text: import datetime
  import hashlib
  import itertools
  import logging
  import os
  import time
  from collections import defaultdict
  from dataclasses import asdict, dataclass, field
  from operator import itemgetter
  from typing import (
      IO,
      AbstractSet,
      Any,
      Callable,
      Collection,
      Dict,
      Iterable,
      List,
      Mapping,
      Optional,
      Sequence,
      Set,
      Tuple,
      Union,
  )
  
  import django.db.utils
  import orjson
  from django.conf import settings
  from django.contrib.contenttypes.models import ContentType
  from django.core.exceptions import ValidationError
  from django.db import IntegrityError, connection, transaction
  from django.db.models import Count, Exists, F, OuterRef, Q, Sum
  from django.db.models.query import QuerySet
  from django.utils.html import escape
  from django.utils.timezone import now as timezone_now
  from django.utils.translation import gettext as _
  from django.utils.translation import override as override_language
  from psycopg2.extras import execute_values
  from psycopg2.sql import SQL
  from typing_extensions import TypedDict
  
  from analytics.lib.counts import COUNT_STATS, do_increment_logging_stat
  from analytics.models import RealmCount, StreamCount
  from confirmation import settings as confirmation_settings
  from confirmation.models import (
      Confirmation,
      confirmation_url,
      create_confirmation_link,
      generate_key,
  )
  from zerver.decorator import statsd_increment
  from zerver.lib import retention as retention
  from zerver.lib.addressee import Addressee
  from zerver.lib.alert_words import (
      add_user_alert_words,
      get_alert_word_automaton,
      remove_user_alert_words,
  )
  from zerver.lib.avatar import avatar_url, avatar_url_from_dict
  from zerver.lib.bot_config import ConfigError, get_bot_config, get_bot_configs, set_bot_config
  from zerver.lib.bulk_create import bulk_create_users
  from zerver.lib.cache import (
      bot_dict_fields,
      cache_delete,
      cache_delete_many,
      cache_set,
      cache_set_many,
      cache_with_key,
      delete_user_profile_caches,
      display_recipient_cache_key,
      flush_user_profile,
      get_stream_cache_key,
      to_dict_cache_key_id,
      user_profile_by_api_key_cache_key,
      user_profile_delivery_email_cache_key,
  )
  from zerver.lib.create_user import create_user, get_display_email_address
  from zerver.lib.email_mirror_helpers import encode_email_address, encode_email_address_helper
  from zerver.lib.email_notifications import enqueue_welcome_emails
  from zerver.lib.email_validation import (
      email_reserved_for_system_bots_error,
      get_existing_user_errors,
      get_realm_email_validator,
      validate_email_is_valid,
  )
  from zerver.lib.emoji import check_emoji_request, emoji_name_to_emoji_code, get_emoji_file_name
  from zerver.lib.exceptions import (
      InvitationError,
      JsonableError,
      MarkdownRenderingException,
      StreamDoesNotExistError,
      StreamWithIDDoesNotExistError,
      ZephyrMessageAlreadySentException,
  )
  from zerver.lib.export import get_realm_exports_serialized
  from zerver.lib.external_accounts import DEFAULT_EXTERNAL_ACCOUNTS
  from zerver.lib.hotspots import get_next_hotspots
  from zerver.lib.i18n import get_language_name
  from zerver.lib.markdown import MessageRenderingResult, topic_links
  from zerver.lib.markdown import version as markdown_version
  from zerver.lib.mention import MentionData
  from zerver.lib.message import (
      MessageDict,
      SendMessageRequest,
      access_message,
      get_last_message_id,
      normalize_body,
      render_markdown,
      truncate_topic,
      update_first_visible_message_id,
      wildcard_mention_allowed,
  )
  from zerver.lib.notification_data import UserMessageNotificationsData, get_user_group_mentions_data
  from zerver.lib.pysa import mark_sanitized
  from zerver.lib.queue import queue_json_publish
  from zerver.lib.realm_icon import realm_icon_url
  from zerver.lib.realm_logo import get_realm_logo_data
  from zerver.lib.retention import move_messages_to_archive
  from zerver.lib.send_email import (
      FromAddress,
      clear_scheduled_emails,
      clear_scheduled_invitation_emails,
      send_email,
      send_email_to_admins,
  )
  from zerver.lib.server_initialization import create_internal_realm, server_initialized
  from zerver.lib.sessions import delete_user_sessions
  from zerver.lib.storage import static_path
  from zerver.lib.stream_subscription import (
      SubInfo,
      bulk_get_private_peers,
      bulk_get_subscriber_peer_info,
      get_active_subscriptions_for_stream_id,
      get_bulk_stream_subscriber_info,
      get_stream_subscriptions_for_user,
      get_stream_subscriptions_for_users,
      get_subscribed_stream_ids_for_user,
      get_subscriptions_for_send_message,
      get_user_ids_for_streams,
      num_subscribers_for_stream_id,
      subscriber_ids_with_stream_history_access,
  )
  from zerver.lib.stream_topic import StreamTopicTarget
  from zerver.lib.streams import (
      access_stream_by_id,
      access_stream_for_send_message,
      can_access_stream_user_ids,
      check_stream_access_based_on_stream_post_policy,
      check_stream_name,
      create_stream_if_needed,
      get_default_value_for_history_public_to_subscribers,
      render_stream_description,
      send_stream_creation_event,
      subscribed_to_stream,
  )
  from zerver.lib.timestamp import datetime_to_timestamp, timestamp_to_datetime
  from zerver.lib.timezone import canonicalize_timezone
  from zerver.lib.topic import (
      LEGACY_PREV_TOPIC,
      ORIG_TOPIC,
      RESOLVED_TOPIC_PREFIX,
      TOPIC_LINKS,
      TOPIC_NAME,
      filter_by_exact_message_topic,
      filter_by_topic_name_via_message,
      save_message_for_edit_use_case,
      update_edit_history,
      update_messages_for_topic_edit,
  )
  from zerver.lib.topic_mutes import add_topic_mute, get_topic_mutes, remove_topic_mute
  from zerver.lib.types import ProfileFieldData
  from zerver.lib.upload import (
      claim_attachment,
      delete_avatar_image,
      delete_export_tarball,
      delete_message_image,
      upload_emoji_image,
  )
  from zerver.lib.user_groups import access_user_group_by_id, create_user_group
  from zerver.lib.user_mutes import add_user_mute, get_muting_users, get_user_mutes
  from zerver.lib.user_status import update_user_status
  from zerver.lib.users import (
      check_bot_name_available,
      check_full_name,
      format_user_row,
      get_api_key,
      user_profile_to_user_row,
  )
  from zerver.lib.utils import generate_api_key, log_statsd_event
  from zerver.lib.validator import check_widget_content
  from zerver.lib.widget import do_widget_post_save_actions, is_widget_message
  from zerver.models import (
      Attachment,
      Client,
      CustomProfileField,
      CustomProfileFieldValue,
      DefaultStream,
      DefaultStreamGroup,
      Draft,
      EmailChangeStatus,
      Message,
      MultiuseInvite,
      MutedUser,
      PreregistrationUser,
      Reaction,
      Realm,
      RealmAuditLog,
      RealmDomain,
      RealmEmoji,
      RealmFilter,
      RealmPlayground,
      RealmUserDefault,
      Recipient,
      ScheduledEmail,
      ScheduledMessage,
      Service,
      Stream,
      SubMessage,
      Subscription,
      UserActivity,
      UserActivityInterval,
      UserGroup,
      UserGroupMembership,
      UserHotspot,
      UserMessage,
      UserPresence,
      UserProfile,
      UserStatus,
      active_non_guest_user_ids,
      active_user_ids,
      custom_profile_fields_for_realm,
      filter_to_valid_prereg_users,
      get_active_streams,
      get_bot_dicts_in_realm,
      get_bot_services,
      get_client,
      get_default_stream_groups,
      get_huddle_recipient,
      get_huddle_user_ids,
      get_old_unclaimed_attachments,
      get_realm,
      get_realm_playgrounds,
      get_stream,
      get_stream_by_id_in_realm,
      get_system_bot,
      get_user_by_delivery_email,
      get_user_by_id_in_realm_including_cross_realm,
      get_user_profile_by_id,
      is_cross_realm_bot_email,
      linkifiers_for_realm,
      query_for_ids,
      realm_filters_for_realm,
      validate_attachment_request,
  )
  from zerver.tornado.django_api import send_event
  
  if settings.BILLING_ENABLED:
      from corporate.lib.stripe import (
          downgrade_now_without_creating_additional_invoices,
          update_license_ledger_if_needed,
      )
  
  
  @dataclass
  class SubscriptionInfo:
      subscriptions: List[Dict[str, Any]]
      unsubscribed: List[Dict[str, Any]]
      never_subscribed: List[Dict[str, Any]]
  
  
  # These are hard to type-check because of the API_FIELDS loops.
  RawStreamDict = Dict[str, Any]
  RawSubscriptionDict = Dict[str, Any]
  
  ONBOARDING_TOTAL_MESSAGES = 1000
  ONBOARDING_UNREAD_MESSAGES = 20
  
  STREAM_ASSIGNMENT_COLORS = [
      "#76ce90",
      "#fae589",
      "#a6c7e5",
      "#e79ab5",
      "#bfd56f",
      "#f4ae55",
      "#b0a5fd",
      "#addfe5",
      "#f5ce6e",
      "#c2726a",
      "#94c849",
      "#bd86e5",
      "#ee7e4a",
      "#a6dcbf",
      "#95a5fd",
      "#53a063",
      "#9987e1",
      "#e4523d",
      "#c2c2c2",
      "#4f8de4",
      "#c6a8ad",
      "#e7cc4d",
      "#c8bebf",
      "#a47462",
  ]
  
  
  def subscriber_info(user_id: int) -> Dict[str, Any]:
      return {"id": user_id, "flags": ["read"]}
  
  
  def bot_owner_user_ids(user_profile: UserProfile) -> Set[int]:
      is_private_bot = (
          user_profile.default_sending_stream
          and user_profile.default_sending_stream.invite_only
          or user_profile.default_events_register_stream
          and user_profile.default_events_register_stream.invite_only
      )
      if is_private_bot:
          return {user_profile.bot_owner_id}
      else:
          users = {user.id for user in user_profile.realm.get_human_admin_users()}
          users.add(user_profile.bot_owner_id)
          return users
  
  
  def realm_user_count(realm: Realm) -> int:
      return UserProfile.objects.filter(realm=realm, is_active=True, is_bot=False).count()
  
  
  def realm_user_count_by_role(realm: Realm) -> Dict[str, Any]:
      human_counts = {
          str(UserProfile.ROLE_REALM_ADMINISTRATOR): 0,
          str(UserProfile.ROLE_REALM_OWNER): 0,
          str(UserProfile.ROLE_MODERATOR): 0,
          str(UserProfile.ROLE_MEMBER): 0,
          str(UserProfile.ROLE_GUEST): 0,
      }
      for value_dict in list(
          UserProfile.objects.filter(realm=realm, is_bot=False, is_active=True)
          .values("role")
          .annotate(Count("role"))
      ):
          human_counts[str(value_dict["role"])] = value_dict["role__count"]
      bot_count = UserProfile.objects.filter(realm=realm, is_bot=True, is_active=True).count()
      return {
          RealmAuditLog.ROLE_COUNT_HUMANS: human_counts,
          RealmAuditLog.ROLE_COUNT_BOTS: bot_count,
      }
  
  
  def get_signups_stream(realm: Realm) -> Stream:
      # This one-liner helps us work around a lint rule.
      return get_stream("signups", realm)
  
  
  def send_message_to_signup_notification_stream(
      sender: UserProfile, realm: Realm, message: str, topic_name: str = _("signups")
  ) -> None:
      signup_notifications_stream = realm.get_signup_notifications_stream()
      if signup_notifications_stream is None:
          return
  
      with override_language(realm.default_language):
          internal_send_stream_message(sender, signup_notifications_stream, topic_name, message)
  
  
  def notify_new_user(user_profile: UserProfile) -> None:
      user_count = realm_user_count(user_profile.realm)
      sender_email = settings.NOTIFICATION_BOT
      sender = get_system_bot(sender_email, user_profile.realm_id)
  
      is_first_user = user_count == 1
      if not is_first_user:
          message = _("{user} just signed up for Zulip. (total: {user_count})").format(
              user=f"@_**{user_profile.full_name}|{user_profile.id}**", user_count=user_count
          )
  
          if settings.BILLING_ENABLED:
              from corporate.lib.registration import generate_licenses_low_warning_message_if_required
  
              licenses_low_warning_message = generate_licenses_low_warning_message_if_required(
                  user_profile.realm
              )
              if licenses_low_warning_message is not None:
                  message += "\n"
                  message += licenses_low_warning_message
  
          send_message_to_signup_notification_stream(sender, user_profile.realm, message)
  
      # We also send a notification to the Zulip administrative realm
      admin_realm = get_realm(settings.SYSTEM_BOT_REALM)
      admin_realm_sender = get_system_bot(sender_email, admin_realm.id)
      try:
          # Check whether the stream exists
          signups_stream = get_signups_stream(admin_realm)
          # We intentionally use the same strings as above to avoid translation burden.
          message = _("{user} just signed up for Zulip. (total: {user_count})").format(
              user=f"{user_profile.full_name} <`{user_profile.email}`>", user_count=user_count
          )
          internal_send_stream_message(
              admin_realm_sender, signups_stream, user_profile.realm.display_subdomain, message
          )
  
      except Stream.DoesNotExist:
          # If the signups stream hasn't been created in the admin
          # realm, don't auto-create it to send to it; just do nothing.
          pass
  
  
  def notify_invites_changed(user_profile: UserProfile) -> None:
      event = dict(type="invites_changed")
      admin_ids = [user.id for user in user_profile.realm.get_admin_users_and_bots()]
      send_event(user_profile.realm, event, admin_ids)
  
  
  def add_new_user_history(user_profile: UserProfile, streams: Iterable[Stream]) -> None:
      """Give you the last ONBOARDING_TOTAL_MESSAGES messages on your public
      streams, so you have something to look at in your home view once
      you finish the tutorial.  The most recent ONBOARDING_UNREAD_MESSAGES
      are marked unread.
      """
      one_week_ago = timezone_now() - datetime.timedelta(weeks=1)
  
      recipient_ids = [stream.recipient_id for stream in streams if not stream.invite_only]
      recent_messages = Message.objects.filter(
          recipient_id__in=recipient_ids, date_sent__gt=one_week_ago
      ).order_by("-id")
      message_ids_to_use = list(
          reversed(recent_messages.values_list("id", flat=True)[0:ONBOARDING_TOTAL_MESSAGES])
      )
      if len(message_ids_to_use) == 0:
          return
  
      # Handle the race condition where a message arrives between
      # bulk_add_subscriptions above and the Message query just above
      already_ids = set(
          UserMessage.objects.filter(
              message_id__in=message_ids_to_use, user_profile=user_profile
          ).values_list("message_id", flat=True)
      )
  
      # Mark the newest ONBOARDING_UNREAD_MESSAGES as unread.
      marked_unread = 0
      ums_to_create = []
      for message_id in reversed(message_ids_to_use):
          if message_id in already_ids:
              continue
  
          um = UserMessage(user_profile=user_profile, message_id=message_id)
          if marked_unread < ONBOARDING_UNREAD_MESSAGES:
              marked_unread += 1
          else:
              um.flags = UserMessage.flags.read
          ums_to_create.append(um)
  
      UserMessage.objects.bulk_create(reversed(ums_to_create))
  
  
  # Does the processing for a new user account:
  # * Subscribes to default/invitation streams
  # * Fills in some recent historical messages
  # * Notifies other users in realm and Zulip about the signup
  # * Deactivates PreregistrationUser objects
  def process_new_human_user(
      user_profile: UserProfile,
      prereg_user: Optional[PreregistrationUser] = None,
      default_stream_groups: Sequence[DefaultStreamGroup] = [],
      realm_creation: bool = False,
  ) -> None:
      realm = user_profile.realm
  
      mit_beta_user = realm.is_zephyr_mirror_realm
      if prereg_user is not None:
          streams: List[Stream] = list(prereg_user.streams.all())
          acting_user: Optional[UserProfile] = prereg_user.referred_by
      else:
          streams = []
          acting_user = None
  
      # If the user's invitation didn't explicitly list some streams, we
      # add the default streams
      if len(streams) == 0:
          streams = get_default_subs(user_profile)
  
      for default_stream_group in default_stream_groups:
          default_stream_group_streams = default_stream_group.streams.all()
          for stream in default_stream_group_streams:
              if stream not in streams:
                  streams.append(stream)
  
      bulk_add_subscriptions(
          realm,
          streams,
          [user_profile],
          from_user_creation=True,
          acting_user=acting_user,
      )
  
      add_new_user_history(user_profile, streams)
  
      # mit_beta_users don't have a referred_by field
      if not mit_beta_user and prereg_user is not None and prereg_user.referred_by is not None:
          # This is a cross-realm private message.
          with override_language(prereg_user.referred_by.default_language):
              internal_send_private_message(
                  get_system_bot(settings.NOTIFICATION_BOT, prereg_user.referred_by.realm_id),
                  prereg_user.referred_by,
                  _("{user} accepted your invitation to join Zulip!").format(
                      user=f"{user_profile.full_name} <`{user_profile.email}`>"
                  ),
              )
  
      revoke_preregistration_users(user_profile, prereg_user, realm_creation)
      if not realm_creation and prereg_user is not None and prereg_user.referred_by is not None:
          notify_invites_changed(user_profile)
  
      notify_new_user(user_profile)
      # Clear any scheduled invitation emails to prevent them
      # from being sent after the user is created.
      clear_scheduled_invitation_emails(user_profile.delivery_email)
      if realm.send_welcome_emails:
          enqueue_welcome_emails(user_profile, realm_creation)
  
      # We have an import loop here; it's intentional, because we want
      # to keep all the onboarding code in zerver/lib/onboarding.py.
      from zerver.lib.onboarding import send_initial_pms
  
      send_initial_pms(user_profile)
  
  
  def revoke_preregistration_users(
      created_user_profile: UserProfile,
      used_preregistration_user: Optional[PreregistrationUser],
      realm_creation: bool,
  ) -> None:
      if used_preregistration_user is None:
          assert not realm_creation, "realm_creation should only happen with a PreregistrationUser"
  
      if used_preregistration_user is not None:
          used_preregistration_user.status = confirmation_settings.STATUS_ACTIVE
          used_preregistration_user.save(update_fields=["status"])
  
      # In the special case of realm creation, there can be no additional PreregistrationUser
      # for us to want to modify - because other realm_creation PreregistrationUsers should be
      # left usable for creating different realms.
      if realm_creation:
          return
  
      # Mark any other PreregistrationUsers in the realm that are STATUS_ACTIVE as
      # inactive so we can keep track of the PreregistrationUser we
      # actually used for analytics.
      if used_preregistration_user is not None:
          PreregistrationUser.objects.filter(
              email__iexact=created_user_profile.delivery_email, realm=created_user_profile.realm
          ).exclude(id=used_preregistration_user.id).update(
              status=confirmation_settings.STATUS_REVOKED
          )
      else:
          PreregistrationUser.objects.filter(
              email__iexact=created_user_profile.delivery_email, realm=created_user_profile.realm
          ).update(status=confirmation_settings.STATUS_REVOKED)
  
  
  def notify_created_user(user_profile: UserProfile) -> None:
      user_row = user_profile_to_user_row(user_profile)
      person = format_user_row(
          user_profile.realm,
          user_profile,
          user_row,
          # Since we don't know what the client
          # supports at this point in the code, we
          # just assume client_gravatar and
          # user_avatar_url_field_optional = False :(
          client_gravatar=False,
          user_avatar_url_field_optional=False,
          # We assume there's no custom profile
          # field data for a new user; initial
          # values are expected to be added in a
          # later event.
          custom_profile_field_data={},
      )
      event: Dict[str, Any] = dict(type="realm_user", op="add", person=person)
      send_event(user_profile.realm, event, active_user_ids(user_profile.realm_id))
  
  
  def created_bot_event(user_profile: UserProfile) -> Dict[str, Any]:
      def stream_name(stream: Optional[Stream]) -> Optional[str]:
          if not stream:
              return None
          return stream.name
  
      default_sending_stream_name = stream_name(user_profile.default_sending_stream)
      default_events_register_stream_name = stream_name(user_profile.default_events_register_stream)
  
      bot = dict(
          email=user_profile.email,
          user_id=user_profile.id,
          full_name=user_profile.full_name,
          bot_type=user_profile.bot_type,
          is_active=user_profile.is_active,
          api_key=get_api_key(user_profile),
          default_sending_stream=default_sending_stream_name,
          default_events_register_stream=default_events_register_stream_name,
          default_all_public_streams=user_profile.default_all_public_streams,
          avatar_url=avatar_url(user_profile),
          services=get_service_dicts_for_bot(user_profile.id),
      )
  
      # Set the owner key only when the bot has an owner.
      # The default bots don't have an owner. So don't
      # set the owner key while reactivating them.
      if user_profile.bot_owner is not None:
          bot["owner_id"] = user_profile.bot_owner.id
  
      return dict(type="realm_bot", op="add", bot=bot)
  
  
  def notify_created_bot(user_profile: UserProfile) -> None:
      event = created_bot_event(user_profile)
      send_event(user_profile.realm, event, bot_owner_user_ids(user_profile))
  
  
  def create_users(
      realm: Realm, name_list: Iterable[Tuple[str, str]], bot_type: Optional[int] = None
  ) -> None:
      user_set = set()
      for full_name, email in name_list:
          user_set.add((email, full_name, True))
      bulk_create_users(realm, user_set, bot_type)
  
  
  def do_create_user(
      email: str,
      password: Optional[str],
      realm: Realm,
      full_name: str,
      bot_type: Optional[int] = None,
      role: Optional[int] = None,
      bot_owner: Optional[UserProfile] = None,
      tos_version: Optional[str] = None,
      timezone: str = "",
      avatar_source: str = UserProfile.AVATAR_FROM_GRAVATAR,
      default_sending_stream: Optional[Stream] = None,
      default_events_register_stream: Optional[Stream] = None,
      default_all_public_streams: Optional[bool] = None,
      prereg_user: Optional[PreregistrationUser] = None,
      default_stream_groups: Sequence[DefaultStreamGroup] = [],
      source_profile: Optional[UserProfile] = None,
      realm_creation: bool = False,
      *,
      acting_user: Optional[UserProfile],
      enable_marketing_emails: bool = True,
  ) -> UserProfile:
  
      user_profile = create_user(
          email=email,
          password=password,
          realm=realm,
          full_name=full_name,
          role=role,
          bot_type=bot_type,
          bot_owner=bot_owner,
          tos_version=tos_version,
          timezone=timezone,
          avatar_source=avatar_source,
          default_sending_stream=default_sending_stream,
          default_events_register_stream=default_events_register_stream,
          default_all_public_streams=default_all_public_streams,
          source_profile=source_profile,
          enable_marketing_emails=enable_marketing_emails,
      )
  
      event_time = user_profile.date_joined
      if not acting_user:
          acting_user = user_profile
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=acting_user,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_CREATED,
          event_time=event_time,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.ROLE_COUNT: realm_user_count_by_role(user_profile.realm),
              }
          ).decode(),
      )
  
      if realm_creation:
          # If this user just created a realm, make sure they are
          # properly tagged as the creator of the realm.
          realm_creation_audit_log = (
              RealmAuditLog.objects.filter(event_type=RealmAuditLog.REALM_CREATED, realm=realm)
              .order_by("id")
              .last()
          )
          assert realm_creation_audit_log is not None
          realm_creation_audit_log.acting_user = user_profile
          realm_creation_audit_log.save(update_fields=["acting_user"])
  
      do_increment_logging_stat(
          user_profile.realm,
          COUNT_STATS["active_users_log:is_bot:day"],
          user_profile.is_bot,
          event_time,
      )
      if settings.BILLING_ENABLED:
          update_license_ledger_if_needed(user_profile.realm, event_time)
  
      # Note that for bots, the caller will send an additional event
      # with bot-specific info like services.
      notify_created_user(user_profile)
      if bot_type is None:
          process_new_human_user(
              user_profile,
              prereg_user=prereg_user,
              default_stream_groups=default_stream_groups,
              realm_creation=realm_creation,
          )
      return user_profile
  
  
  def do_activate_mirror_dummy_user(
      user_profile: UserProfile, *, acting_user: Optional[UserProfile]
  ) -> None:
      """Called to have a user "take over" a "mirror dummy" user
      (i.e. is_mirror_dummy=True) account when they sign up with the
      same email address.
  
      Essentially, the result should be as though we had created the
      UserProfile just now with do_create_user, except that the mirror
      dummy user may appear as the recipient or sender of messages from
      before their account was fully created.
  
      TODO: This function likely has bugs resulting from this being a
      parallel code path to do_create_user; e.g. it likely does not
      handle preferences or default streams properly.
      """
      with transaction.atomic():
          change_user_is_active(user_profile, True)
          user_profile.is_mirror_dummy = False
          user_profile.set_unusable_password()
          user_profile.date_joined = timezone_now()
          user_profile.tos_version = settings.TOS_VERSION
          user_profile.save(
              update_fields=["date_joined", "password", "is_mirror_dummy", "tos_version"]
          )
  
          event_time = user_profile.date_joined
          RealmAuditLog.objects.create(
              realm=user_profile.realm,
              modified_user=user_profile,
              acting_user=acting_user,
              event_type=RealmAuditLog.USER_ACTIVATED,
              event_time=event_time,
              extra_data=orjson.dumps(
                  {
                      RealmAuditLog.ROLE_COUNT: realm_user_count_by_role(user_profile.realm),
                  }
              ).decode(),
          )
          do_increment_logging_stat(
              user_profile.realm,
              COUNT_STATS["active_users_log:is_bot:day"],
              user_profile.is_bot,
              event_time,
          )
          if settings.BILLING_ENABLED:
              update_license_ledger_if_needed(user_profile.realm, event_time)
  
      notify_created_user(user_profile)
  
  
  def do_reactivate_user(user_profile: UserProfile, *, acting_user: Optional[UserProfile]) -> None:
      """Reactivate a user that had previously been deactivated"""
      with transaction.atomic():
          change_user_is_active(user_profile, True)
  
          event_time = timezone_now()
          RealmAuditLog.objects.create(
              realm=user_profile.realm,
              modified_user=user_profile,
              acting_user=acting_user,
              event_type=RealmAuditLog.USER_REACTIVATED,
              event_time=event_time,
              extra_data=orjson.dumps(
                  {
                      RealmAuditLog.ROLE_COUNT: realm_user_count_by_role(user_profile.realm),
                  }
              ).decode(),
          )
          do_increment_logging_stat(
              user_profile.realm,
              COUNT_STATS["active_users_log:is_bot:day"],
              user_profile.is_bot,
              event_time,
          )
          if settings.BILLING_ENABLED:
              update_license_ledger_if_needed(user_profile.realm, event_time)
  
      notify_created_user(user_profile)
  
      if user_profile.is_bot:
          notify_created_bot(user_profile)
  
  
  def active_humans_in_realm(realm: Realm) -> Sequence[UserProfile]:
      return UserProfile.objects.filter(realm=realm, is_active=True, is_bot=False)
  
  
  def do_set_realm_property(
      realm: Realm, name: str, value: Any, *, acting_user: Optional[UserProfile]
  ) -> None:
      """Takes in a realm object, the name of an attribute to update, the
      value to update and and the user who initiated the update.
      """
      property_type = Realm.property_types[name]
      assert isinstance(
          value, property_type
      ), f"Cannot update {name}: {value} is not an instance of {property_type}"
  
      old_value = getattr(realm, name)
      setattr(realm, name, value)
      realm.save(update_fields=[name])
  
      event = dict(
          type="realm",
          op="update",
          property=name,
          value=value,
      )
      send_event(realm, event, active_user_ids(realm.id))
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=realm,
          event_type=RealmAuditLog.REALM_PROPERTY_CHANGED,
          event_time=event_time,
          acting_user=acting_user,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: value,
                  "property": name,
              }
          ).decode(),
      )
  
      if name == "email_address_visibility":
          if Realm.EMAIL_ADDRESS_VISIBILITY_EVERYONE not in [old_value, value]:
              # We use real email addresses on UserProfile.email only if
              # EMAIL_ADDRESS_VISIBILITY_EVERYONE is configured, so
              # changes between values that will not require changing
              # that field, so we can save work and return here.
              return
  
          user_profiles = UserProfile.objects.filter(realm=realm, is_bot=False)
          for user_profile in user_profiles:
              user_profile.email = get_display_email_address(user_profile)
              # TODO: Design a bulk event for this or force-reload all clients
              send_user_email_update_event(user_profile)
          UserProfile.objects.bulk_update(user_profiles, ["email"])
  
          for user_profile in user_profiles:
              flush_user_profile(sender=UserProfile, instance=user_profile)
  
  
  def do_set_realm_authentication_methods(
      realm: Realm, authentication_methods: Dict[str, bool], *, acting_user: Optional[UserProfile]
  ) -> None:
      old_value = realm.authentication_methods_dict()
      for key, value in list(authentication_methods.items()):
          index = getattr(realm.authentication_methods, key).number
          realm.authentication_methods.set_bit(index, int(value))
      realm.save(update_fields=["authentication_methods"])
      updated_value = realm.authentication_methods_dict()
      RealmAuditLog.objects.create(
          realm=realm,
          event_type=RealmAuditLog.REALM_PROPERTY_CHANGED,
          event_time=timezone_now(),
          acting_user=acting_user,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: updated_value,
                  "property": "authentication_methods",
              }
          ).decode(),
      )
      event = dict(
          type="realm",
          op="update_dict",
          property="default",
          data=dict(authentication_methods=updated_value),
      )
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_set_realm_message_editing(
      realm: Realm,
      allow_message_editing: bool,
      message_content_edit_limit_seconds: int,
      edit_topic_policy: int,
      *,
      acting_user: Optional[UserProfile],
  ) -> None:
      old_values = dict(
          allow_message_editing=realm.allow_message_editing,
          message_content_edit_limit_seconds=realm.message_content_edit_limit_seconds,
          edit_topic_policy=realm.edit_topic_policy,
      )
  
      realm.allow_message_editing = allow_message_editing
      realm.message_content_edit_limit_seconds = message_content_edit_limit_seconds
      realm.edit_topic_policy = edit_topic_policy
  
      event_time = timezone_now()
      updated_properties = dict(
          allow_message_editing=allow_message_editing,
          message_content_edit_limit_seconds=message_content_edit_limit_seconds,
          edit_topic_policy=edit_topic_policy,
      )
  
      for updated_property, updated_value in updated_properties.items():
          if updated_value == old_values[updated_property]:
              continue
          RealmAuditLog.objects.create(
              realm=realm,
              event_type=RealmAuditLog.REALM_PROPERTY_CHANGED,
              event_time=event_time,
              acting_user=acting_user,
              extra_data=orjson.dumps(
                  {
                      RealmAuditLog.OLD_VALUE: old_values[updated_property],
                      RealmAuditLog.NEW_VALUE: updated_value,
                      "property": updated_property,
                  }
              ).decode(),
          )
  
      realm.save(update_fields=list(updated_properties.keys()))
      event = dict(
          type="realm",
          op="update_dict",
          property="default",
          data=updated_properties,
      )
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_set_realm_notifications_stream(
      realm: Realm, stream: Optional[Stream], stream_id: int, *, acting_user: Optional[UserProfile]
  ) -> None:
      old_value = realm.notifications_stream_id
      realm.notifications_stream = stream
      realm.save(update_fields=["notifications_stream"])
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=realm,
          event_type=RealmAuditLog.REALM_PROPERTY_CHANGED,
          event_time=event_time,
          acting_user=acting_user,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: stream_id,
                  "property": "notifications_stream",
              }
          ).decode(),
      )
  
      event = dict(
          type="realm",
          op="update",
          property="notifications_stream_id",
          value=stream_id,
      )
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_set_realm_signup_notifications_stream(
      realm: Realm, stream: Optional[Stream], stream_id: int, *, acting_user: Optional[UserProfile]
  ) -> None:
      old_value = realm.signup_notifications_stream_id
      realm.signup_notifications_stream = stream
      realm.save(update_fields=["signup_notifications_stream"])
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=realm,
          event_type=RealmAuditLog.REALM_PROPERTY_CHANGED,
          event_time=event_time,
          acting_user=acting_user,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: stream_id,
                  "property": "signup_notifications_stream",
              }
          ).decode(),
      )
      event = dict(
          type="realm",
          op="update",
          property="signup_notifications_stream_id",
          value=stream_id,
      )
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_set_realm_user_default_setting(
      realm_user_default: RealmUserDefault,
      name: str,
      value: Any,
      *,
      acting_user: Optional[UserProfile],
  ) -> None:
      old_value = getattr(realm_user_default, name)
      realm = realm_user_default.realm
      event_time = timezone_now()
  
      with transaction.atomic(savepoint=False):
          setattr(realm_user_default, name, value)
          realm_user_default.save(update_fields=[name])
  
          RealmAuditLog.objects.create(
              realm=realm,
              event_type=RealmAuditLog.REALM_DEFAULT_USER_SETTINGS_CHANGED,
              event_time=event_time,
              acting_user=acting_user,
              extra_data=orjson.dumps(
                  {
                      RealmAuditLog.OLD_VALUE: old_value,
                      RealmAuditLog.NEW_VALUE: value,
                      "property": name,
                  }
              ).decode(),
          )
  
      event = dict(
          type="realm_user_settings_defaults",
          op="update",
          property=name,
          value=value,
      )
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_deactivate_realm(realm: Realm, *, acting_user: Optional[UserProfile]) -> None:
      """
      Deactivate this realm. Do NOT deactivate the users -- we need to be able to
      tell the difference between users that were intentionally deactivated,
      e.g. by a realm admin, and users who can't currently use Zulip because their
      realm has been deactivated.
      """
      if realm.deactivated:
          return
  
      realm.deactivated = True
      realm.save(update_fields=["deactivated"])
  
      if settings.BILLING_ENABLED:
          downgrade_now_without_creating_additional_invoices(realm)
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=realm,
          event_type=RealmAuditLog.REALM_DEACTIVATED,
          event_time=event_time,
          acting_user=acting_user,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.ROLE_COUNT: realm_user_count_by_role(realm),
              }
          ).decode(),
      )
  
      ScheduledEmail.objects.filter(realm=realm).delete()
      for user in active_humans_in_realm(realm):
          # Don't deactivate the users, but do delete their sessions so they get
          # bumped to the login screen, where they'll get a realm deactivation
          # notice when they try to log in.
          delete_user_sessions(user)
  
      # This event will only ever be received by clients with an active
      # longpoll connection, because by this point clients will be
      # unable to authenticate again to their event queue (triggering an
      # immediate reload into the page explaining the realm was
      # deactivated). So the purpose of sending this is to flush all
      # active longpoll connections for the realm.
      event = dict(type="realm", op="deactivated", realm_id=realm.id)
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_reactivate_realm(realm: Realm) -> None:
      realm.deactivated = False
      realm.save(update_fields=["deactivated"])
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=realm,
          event_type=RealmAuditLog.REALM_REACTIVATED,
          event_time=event_time,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.ROLE_COUNT: realm_user_count_by_role(realm),
              }
          ).decode(),
      )
  
  
  def do_change_realm_subdomain(
      realm: Realm, new_subdomain: str, *, acting_user: Optional[UserProfile]
  ) -> None:
      old_subdomain = realm.subdomain
      old_uri = realm.uri
      realm.string_id = new_subdomain
      realm.save(update_fields=["string_id"])
      RealmAuditLog.objects.create(
          realm=realm,
          event_type=RealmAuditLog.REALM_SUBDOMAIN_CHANGED,
          event_time=timezone_now(),
          acting_user=acting_user,
          extra_data={"old_subdomain": old_subdomain, "new_subdomain": new_subdomain},
      )
  
      # If a realm if being renamed multiple times, we should find all the placeholder
      # realms and reset their deactivated_redirect field to point to the new realm uri
      placeholder_realms = Realm.objects.filter(deactivated_redirect=old_uri, deactivated=True)
      for placeholder_realm in placeholder_realms:
          do_add_deactivated_redirect(placeholder_realm, realm.uri)
  
      # When we change a realm's subdomain the realm with old subdomain is basically
      # deactivated. We are creating a deactivated realm using old subdomain and setting
      # it's deactivated redirect to new_subdomain so that we can tell the users that
      # the realm has been moved to a new subdomain.
      placeholder_realm = do_create_realm(old_subdomain, realm.name)
      do_deactivate_realm(placeholder_realm, acting_user=None)
      do_add_deactivated_redirect(placeholder_realm, realm.uri)
  
  
  def do_add_deactivated_redirect(realm: Realm, redirect_url: str) -> None:
      realm.deactivated_redirect = redirect_url
      realm.save(update_fields=["deactivated_redirect"])
  
  
  def do_scrub_realm(realm: Realm, *, acting_user: Optional[UserProfile]) -> None:
      if settings.BILLING_ENABLED:
          downgrade_now_without_creating_additional_invoices(realm)
  
      users = UserProfile.objects.filter(realm=realm)
      for user in users:
          do_delete_messages_by_sender(user)
          do_delete_avatar_image(user, acting_user=acting_user)
          user.full_name = f"Scrubbed {generate_key()[:15]}"
          scrubbed_email = f"scrubbed-{generate_key()[:15]}@{realm.host}"
          user.email = scrubbed_email
          user.delivery_email = scrubbed_email
          user.save(update_fields=["full_name", "email", "delivery_email"])
  
      do_remove_realm_custom_profile_fields(realm)
      Attachment.objects.filter(realm=realm).delete()
  
      RealmAuditLog.objects.create(
          realm=realm,
          event_time=timezone_now(),
          acting_user=acting_user,
          event_type=RealmAuditLog.REALM_SCRUBBED,
      )
  
  
  def do_delete_user(user_profile: UserProfile) -> None:
      if user_profile.realm.is_zephyr_mirror_realm:
          raise AssertionError("Deleting zephyr mirror users is not supported")
  
      do_deactivate_user(user_profile, acting_user=None)
  
      subscribed_huddle_recipient_ids = set(
          Subscription.objects.filter(
              user_profile=user_profile, recipient__type=Recipient.HUDDLE
          ).values_list("recipient_id", flat=True)
      )
      user_id = user_profile.id
      realm = user_profile.realm
      personal_recipient = user_profile.recipient
  
      user_profile.delete()
      # Recipient objects don't get deleted through CASCADE, so we need to handle
      # the user's personal recipient manually. This will also delete all Messages pointing
      # to this recipient (all private messages sent to the user).
      assert personal_recipient is not None
      personal_recipient.delete()
      replacement_user = create_user(
          force_id=user_id,
          email=f"deleteduser{user_id}@{realm.uri}",
          password=None,
          realm=realm,
          full_name=f"Deleted User {user_id}",
          is_mirror_dummy=True,
      )
      subs_to_recreate = [
          Subscription(
              user_profile=replacement_user,
              recipient=recipient,
              is_user_active=replacement_user.is_active,
          )
          for recipient in Recipient.objects.filter(id__in=subscribed_huddle_recipient_ids)
      ]
      Subscription.objects.bulk_create(subs_to_recreate)
  
  
  def change_user_is_active(user_profile: UserProfile, value: bool) -> None:
      """
      Helper function for changing the .is_active field. Not meant as a standalone function
      in production code as properly activating/deactivating users requires more steps.
      This changes the is_active value and saves it, while ensuring
      Subscription.is_user_active values are updated in the same db transaction.
      """
      with transaction.atomic(savepoint=False):
          user_profile.is_active = value
          user_profile.save(update_fields=["is_active"])
          Subscription.objects.filter(user_profile=user_profile).update(is_user_active=value)
  
  
  def get_active_bots_owned_by_user(user_profile: UserProfile) -> QuerySet:
      return UserProfile.objects.filter(is_bot=True, is_active=True, bot_owner=user_profile)
  
  
  def do_deactivate_user(
      user_profile: UserProfile, _cascade: bool = True, *, acting_user: Optional[UserProfile]
  ) -> None:
      if not user_profile.is_active:
          return
  
      if _cascade:
          # We need to deactivate bots before the target user, to ensure
          # that a failure partway through this function cannot result
          # in only the user being deactivated.
          bot_profiles = get_active_bots_owned_by_user(user_profile)
          for profile in bot_profiles:
              do_deactivate_user(profile, _cascade=False, acting_user=acting_user)
  
      with transaction.atomic():
          if user_profile.realm.is_zephyr_mirror_realm:  # nocoverage
              # For zephyr mirror users, we need to make them a mirror dummy
              # again; otherwise, other users won't get the correct behavior
              # when trying to send messages to this person inside Zulip.
              #
              # Ideally, we need to also ensure their zephyr mirroring bot
              # isn't running, but that's a separate issue.
              user_profile.is_mirror_dummy = True
              user_profile.save(update_fields=["is_mirror_dummy"])
  
          change_user_is_active(user_profile, False)
  
          delete_user_sessions(user_profile)
          clear_scheduled_emails(user_profile.id)
  
          event_time = timezone_now()
          RealmAuditLog.objects.create(
              realm=user_profile.realm,
              modified_user=user_profile,
              acting_user=acting_user,
              event_type=RealmAuditLog.USER_DEACTIVATED,
              event_time=event_time,
              extra_data=orjson.dumps(
                  {
                      RealmAuditLog.ROLE_COUNT: realm_user_count_by_role(user_profile.realm),
                  }
              ).decode(),
          )
          do_increment_logging_stat(
              user_profile.realm,
              COUNT_STATS["active_users_log:is_bot:day"],
              user_profile.is_bot,
              event_time,
              increment=-1,
          )
          if settings.BILLING_ENABLED:
              update_license_ledger_if_needed(user_profile.realm, event_time)
  
      event = dict(
          type="realm_user",
          op="remove",
          person=dict(user_id=user_profile.id, full_name=user_profile.full_name),
      )
      send_event(user_profile.realm, event, active_user_ids(user_profile.realm_id))
  
      if user_profile.is_bot:
          event = dict(
              type="realm_bot",
              op="remove",
              bot=dict(user_id=user_profile.id, full_name=user_profile.full_name),
          )
          send_event(user_profile.realm, event, bot_owner_user_ids(user_profile))
  
  
  def do_deactivate_stream(
      stream: Stream, log: bool = True, *, acting_user: Optional[UserProfile]
  ) -> None:
      # We want to mark all messages in the to-be-deactivated stream as
      # read for all users; otherwise they will pollute queries like
      # "Get the user's first unread message".  Since this can be an
      # expensive operation, we do it via the deferred_work queue
      # processor.
      deferred_work_event = {
          "type": "mark_stream_messages_as_read_for_everyone",
          "stream_recipient_id": stream.recipient_id,
      }
      queue_json_publish("deferred_work", deferred_work_event)
  
      # Get the affected user ids *before* we deactivate everybody.
      affected_user_ids = can_access_stream_user_ids(stream)
  
      get_active_subscriptions_for_stream_id(stream.id, include_deactivated_users=True).update(
          active=False
      )
  
      was_invite_only = stream.invite_only
      stream.deactivated = True
      stream.invite_only = True
      # Preserve as much as possible the original stream name while giving it a
      # special prefix that both indicates that the stream is deactivated and
      # frees up the original name for reuse.
      old_name = stream.name
  
      # Prepend a substring of the hashed stream ID to the new stream name
      streamID = str(stream.id)
      stream_id_hash_object = hashlib.sha512(streamID.encode())
      hashed_stream_id = stream_id_hash_object.hexdigest()[0:7]
  
      new_name = (hashed_stream_id + "!DEACTIVATED:" + old_name)[: Stream.MAX_NAME_LENGTH]
  
      stream.name = new_name[: Stream.MAX_NAME_LENGTH]
      stream.save(update_fields=["name", "deactivated", "invite_only"])
  
      # If this is a default stream, remove it, properly sending a
      # notification to browser clients.
      if DefaultStream.objects.filter(realm_id=stream.realm_id, stream_id=stream.id).exists():
          do_remove_default_stream(stream)
  
      default_stream_groups_for_stream = DefaultStreamGroup.objects.filter(streams__id=stream.id)
      for group in default_stream_groups_for_stream:
          do_remove_streams_from_default_stream_group(stream.realm, group, [stream])
  
      # Remove the old stream information from remote cache.
      old_cache_key = get_stream_cache_key(old_name, stream.realm_id)
      cache_delete(old_cache_key)
  
      stream_dict = stream.to_dict()
      stream_dict.update(dict(name=old_name, invite_only=was_invite_only))
      event = dict(type="stream", op="delete", streams=[stream_dict])
      send_event(stream.realm, event, affected_user_ids)
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=stream.realm,
          acting_user=acting_user,
          modified_stream=stream,
          event_type=RealmAuditLog.STREAM_DEACTIVATED,
          event_time=event_time,
      )
  
  
  def send_user_email_update_event(user_profile: UserProfile) -> None:
      payload = dict(user_id=user_profile.id, new_email=user_profile.email)
      send_event(
          user_profile.realm,
          dict(type="realm_user", op="update", person=payload),
          active_user_ids(user_profile.realm_id),
      )
  
  
  def do_change_user_delivery_email(user_profile: UserProfile, new_email: str) -> None:
      delete_user_profile_caches([user_profile])
  
      user_profile.delivery_email = new_email
      if user_profile.email_address_is_realm_public():
          user_profile.email = new_email
          user_profile.save(update_fields=["email", "delivery_email"])
      else:
          user_profile.save(update_fields=["delivery_email"])
  
      # We notify just the target user (and eventually org admins, only
      # when email_address_visibility=EMAIL_ADDRESS_VISIBILITY_ADMINS)
      # about their new delivery email, since that field is private.
      payload = dict(user_id=user_profile.id, delivery_email=new_email)
      event = dict(type="realm_user", op="update", person=payload)
      send_event(user_profile.realm, event, [user_profile.id])
  
      if user_profile.avatar_source == UserProfile.AVATAR_FROM_GRAVATAR:
          # If the user is using Gravatar to manage their email address,
          # their Gravatar just changed, and we need to notify other
          # clients.
          notify_avatar_url_change(user_profile)
  
      if user_profile.email_address_is_realm_public():
          # Additionally, if we're also changing the publicly visible
          # email, we send a new_email event as well.
          send_user_email_update_event(user_profile)
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=user_profile,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_EMAIL_CHANGED,
          event_time=event_time,
      )
  
  
  def do_start_email_change_process(user_profile: UserProfile, new_email: str) -> None:
      old_email = user_profile.delivery_email
      obj = EmailChangeStatus.objects.create(
          new_email=new_email,
          old_email=old_email,
          user_profile=user_profile,
          realm=user_profile.realm,
      )
  
      activation_url = create_confirmation_link(obj, Confirmation.EMAIL_CHANGE)
      from zerver.context_processors import common_context
  
      context = common_context(user_profile)
      context.update(
          old_email=old_email,
          new_email=new_email,
          activate_url=activation_url,
      )
      language = user_profile.default_language
      send_email(
          "zerver/emails/confirm_new_email",
          to_emails=[new_email],
          from_name=FromAddress.security_email_from_name(language=language),
          from_address=FromAddress.tokenized_no_reply_address(),
          language=language,
          context=context,
          realm=user_profile.realm,
      )
  
  
  def compute_irc_user_fullname(email: str) -> str:
      return email.split("@")[0] + " (IRC)"
  
  
  def compute_jabber_user_fullname(email: str) -> str:
      return email.split("@")[0] + " (XMPP)"
  
  
  @cache_with_key(
      lambda realm, email, f: user_profile_delivery_email_cache_key(email, realm),
      timeout=3600 * 24 * 7,
  )
  def create_mirror_user_if_needed(
      realm: Realm, email: str, email_to_fullname: Callable[[str], str]
  ) -> UserProfile:
      try:
          return get_user_by_delivery_email(email, realm)
      except UserProfile.DoesNotExist:
          try:
              # Forge a user for this person
              return create_user(
                  email=email,
                  password=None,
                  realm=realm,
                  full_name=email_to_fullname(email),
                  active=False,
                  is_mirror_dummy=True,
              )
          except IntegrityError:
              return get_user_by_delivery_email(email, realm)
  
  
  def render_incoming_message(
      message: Message,
      content: str,
      user_ids: Set[int],
      realm: Realm,
      mention_data: Optional[MentionData] = None,
      email_gateway: bool = False,
  ) -> MessageRenderingResult:
      realm_alert_words_automaton = get_alert_word_automaton(realm)
      try:
          rendering_result = render_markdown(
              message=message,
              content=content,
              realm=realm,
              realm_alert_words_automaton=realm_alert_words_automaton,
              mention_data=mention_data,
              email_gateway=email_gateway,
          )
      except MarkdownRenderingException:
          raise JsonableError(_("Unable to render message"))
      return rendering_result
  
  
  class RecipientInfoResult(TypedDict):
      active_user_ids: Set[int]
      online_push_user_ids: Set[int]
      pm_mention_email_disabled_user_ids: Set[int]
      pm_mention_push_disabled_user_ids: Set[int]
      stream_email_user_ids: Set[int]
      stream_push_user_ids: Set[int]
      wildcard_mention_user_ids: Set[int]
      muted_sender_user_ids: Set[int]
      um_eligible_user_ids: Set[int]
      long_term_idle_user_ids: Set[int]
      default_bot_user_ids: Set[int]
      service_bot_tuples: List[Tuple[int, int]]
  
  
  def get_recipient_info(
      *,
      realm_id: int,
      recipient: Recipient,
      sender_id: int,
      stream_topic: Optional[StreamTopicTarget],
      possibly_mentioned_user_ids: AbstractSet[int] = set(),
      possible_wildcard_mention: bool = True,
  ) -> RecipientInfoResult:
      stream_push_user_ids: Set[int] = set()
      stream_email_user_ids: Set[int] = set()
      wildcard_mention_user_ids: Set[int] = set()
      muted_sender_user_ids: Set[int] = get_muting_users(sender_id)
  
      if recipient.type == Recipient.PERSONAL:
          # The sender and recipient may be the same id, so
          # de-duplicate using a set.
          message_to_user_ids = list({recipient.type_id, sender_id})
          assert len(message_to_user_ids) in [1, 2]
  
      elif recipient.type == Recipient.STREAM:
          # Anybody calling us w/r/t a stream message needs to supply
          # stream_topic.  We may eventually want to have different versions
          # of this function for different message types.
          assert stream_topic is not None
          user_ids_muting_topic = stream_topic.user_ids_muting_topic()
  
          subscription_rows = (
              get_subscriptions_for_send_message(
                  realm_id=realm_id,
                  stream_id=stream_topic.stream_id,
                  possible_wildcard_mention=possible_wildcard_mention,
                  possibly_mentioned_user_ids=possibly_mentioned_user_ids,
              )
              .annotate(
                  user_profile_email_notifications=F(
                      "user_profile__enable_stream_email_notifications"
                  ),
                  user_profile_push_notifications=F("user_profile__enable_stream_push_notifications"),
                  user_profile_wildcard_mentions_notify=F("user_profile__wildcard_mentions_notify"),
              )
              .values(
                  "user_profile_id",
                  "push_notifications",
                  "email_notifications",
                  "wildcard_mentions_notify",
                  "user_profile_email_notifications",
                  "user_profile_push_notifications",
                  "user_profile_wildcard_mentions_notify",
                  "is_muted",
              )
              .order_by("user_profile_id")
          )
  
          message_to_user_ids = [row["user_profile_id"] for row in subscription_rows]
  
          def should_send(setting: str, row: Dict[str, Any]) -> bool:
              # This implements the structure that the UserProfile stream notification settings
              # are defaults, which can be overridden by the stream-level settings (if those
              # values are not null).
              if row["is_muted"]:
                  return False
              if row["user_profile_id"] in user_ids_muting_topic:
                  return False
              if row[setting] is not None:
                  return row[setting]
              return row["user_profile_" + setting]
  
          stream_push_user_ids = {
              row["user_profile_id"]
              for row in subscription_rows
              # Note: muting a stream overrides stream_push_notify
              if should_send("push_notifications", row)
          }
  
          stream_email_user_ids = {
              row["user_profile_id"]
              for row in subscription_rows
              # Note: muting a stream overrides stream_email_notify
              if should_send("email_notifications", row)
          }
  
          if possible_wildcard_mention:
              # If there's a possible wildcard mention, we need to
              # determine which users would receive a wildcard mention
              # notification for this message should the message indeed
              # contain a wildcard mention.
              #
              # We don't have separate values for push/email
              # notifications here; at this stage, we're just
              # determining whether this wildcard mention should be
              # treated as a mention (and follow the user's mention
              # notification preferences) or a normal message.
              wildcard_mention_user_ids = {
                  row["user_profile_id"]
                  for row in subscription_rows
                  if should_send("wildcard_mentions_notify", row)
              }
  
      elif recipient.type == Recipient.HUDDLE:
          message_to_user_ids = get_huddle_user_ids(recipient)
  
      else:
          raise ValueError("Bad recipient type")
  
      message_to_user_id_set = set(message_to_user_ids)
  
      user_ids = set(message_to_user_id_set)
      # Important note: Because we haven't rendered Markdown yet, we
      # don't yet know which of these possibly-mentioned users was
      # actually mentioned in the message (in other words, the
      # mention syntax might have been in a code block or otherwise
      # escaped).  `get_ids_for` will filter these extra user rows
      # for our data structures not related to bots
      user_ids |= possibly_mentioned_user_ids
  
      if user_ids:
          query = UserProfile.objects.filter(is_active=True).values(
              "id",
              "enable_online_push_notifications",
              "enable_offline_email_notifications",
              "enable_offline_push_notifications",
              "is_bot",
              "bot_type",
              "long_term_idle",
          )
  
          # query_for_ids is fast highly optimized for large queries, and we
          # need this codepath to be fast (it's part of sending messages)
          query = query_for_ids(
              query=query,
              user_ids=sorted(user_ids),
              field="id",
          )
          rows = list(query)
      else:
          # TODO: We should always have at least one user_id as a recipient
          #       of any message we send.  Right now the exception to this
          #       rule is `notify_new_user`, which, at least in a possibly
          #       contrived test scenario, can attempt to send messages
          #       to an inactive bot.  When we plug that hole, we can avoid
          #       this `else` clause and just `assert(user_ids)`.
          #
          # UPDATE: It's February 2020 (and a couple years after the above
          #         comment was written).  We have simplified notify_new_user
          #         so that it should be a little easier to reason about.
          #         There is currently some cleanup to how we handle cross
          #         realm bots that is still under development.  Once that
          #         effort is complete, we should be able to address this
          #         to-do.
          rows = []
  
      def get_ids_for(f: Callable[[Dict[str, Any]], bool]) -> Set[int]:
          """Only includes users on the explicit message to line"""
          return {row["id"] for row in rows if f(row)} & message_to_user_id_set
  
      def is_service_bot(row: Dict[str, Any]) -> bool:
          return row["is_bot"] and (row["bot_type"] in UserProfile.SERVICE_BOT_TYPES)
  
      active_user_ids = get_ids_for(lambda r: True)
      online_push_user_ids = get_ids_for(
          lambda r: r["enable_online_push_notifications"],
      )
  
      # We deal with only the users who have disabled this setting, since that
      # will ususally be much smaller a set than those who have enabled it (which
      # is the default)
      pm_mention_email_disabled_user_ids = get_ids_for(
          lambda r: not r["enable_offline_email_notifications"]
      )
      pm_mention_push_disabled_user_ids = get_ids_for(
          lambda r: not r["enable_offline_push_notifications"]
      )
  
      # Service bots don't get UserMessage rows.
      um_eligible_user_ids = get_ids_for(
          lambda r: not is_service_bot(r),
      )
  
      long_term_idle_user_ids = get_ids_for(
          lambda r: r["long_term_idle"],
      )
  
      # These two bot data structures need to filter from the full set
      # of users who either are receiving the message or might have been
      # mentioned in it, and so can't use get_ids_for.
      #
      # Further in the do_send_messages code path, once
      # `mentioned_user_ids` has been computed via Markdown, we'll filter
      # these data structures for just those users who are either a
      # direct recipient or were mentioned; for now, we're just making
      # sure we have the data we need for that without extra database
      # queries.
      default_bot_user_ids = {
          row["id"] for row in rows if row["is_bot"] and row["bot_type"] == UserProfile.DEFAULT_BOT
      }
  
      service_bot_tuples = [(row["id"], row["bot_type"]) for row in rows if is_service_bot(row)]
  
      info: RecipientInfoResult = dict(
          active_user_ids=active_user_ids,
          online_push_user_ids=online_push_user_ids,
          pm_mention_email_disabled_user_ids=pm_mention_email_disabled_user_ids,
          pm_mention_push_disabled_user_ids=pm_mention_push_disabled_user_ids,
          stream_push_user_ids=stream_push_user_ids,
          stream_email_user_ids=stream_email_user_ids,
          wildcard_mention_user_ids=wildcard_mention_user_ids,
          muted_sender_user_ids=muted_sender_user_ids,
          um_eligible_user_ids=um_eligible_user_ids,
          long_term_idle_user_ids=long_term_idle_user_ids,
          default_bot_user_ids=default_bot_user_ids,
          service_bot_tuples=service_bot_tuples,
      )
      return info
  
  
  def get_service_bot_events(
      sender: UserProfile,
      service_bot_tuples: List[Tuple[int, int]],
      mentioned_user_ids: Set[int],
      active_user_ids: Set[int],
      recipient_type: int,
  ) -> Dict[str, List[Dict[str, Any]]]:
  
      event_dict: Dict[str, List[Dict[str, Any]]] = defaultdict(list)
  
      # Avoid infinite loops by preventing messages sent by bots from generating
      # Service events.
      if sender.is_bot:
          return event_dict
  
      def maybe_add_event(user_profile_id: int, bot_type: int) -> None:
          if bot_type == UserProfile.OUTGOING_WEBHOOK_BOT:
              queue_name = "outgoing_webhooks"
          elif bot_type == UserProfile.EMBEDDED_BOT:
              queue_name = "embedded_bots"
          else:
              logging.error(
                  "Unexpected bot_type for Service bot id=%s: %s",
                  user_profile_id,
                  bot_type,
              )
              return
  
          is_stream = recipient_type == Recipient.STREAM
  
          # Important note: service_bot_tuples may contain service bots
          # who were not actually mentioned in the message (e.g. if
          # mention syntax for that bot appeared in a code block).
          # Thus, it is important to filter any users who aren't part of
          # either mentioned_user_ids (the actual mentioned users) or
          # active_user_ids (the actual recipients).
          #
          # So even though this is implied by the logic below, we filter
          # these not-actually-mentioned users here, to help keep this
          # function future-proof.
          if user_profile_id not in mentioned_user_ids and user_profile_id not in active_user_ids:
              return
  
          # Mention triggers, for stream messages
          if is_stream and user_profile_id in mentioned_user_ids:
              trigger = "mention"
          # PM triggers for personal and huddle messages
          elif (not is_stream) and (user_profile_id in active_user_ids):
              trigger = "private_message"
          else:
              return
  
          event_dict[queue_name].append(
              {
                  "trigger": trigger,
                  "user_profile_id": user_profile_id,
              }
          )
  
      for user_profile_id, bot_type in service_bot_tuples:
          maybe_add_event(
              user_profile_id=user_profile_id,
              bot_type=bot_type,
          )
  
      return event_dict
  
  
  def do_schedule_messages(send_message_requests: Sequence[SendMessageRequest]) -> List[int]:
      scheduled_messages: List[ScheduledMessage] = []
  
      for send_request in send_message_requests:
          scheduled_message = ScheduledMessage()
          scheduled_message.sender = send_request.message.sender
          scheduled_message.recipient = send_request.message.recipient
          topic_name = send_request.message.topic_name()
          scheduled_message.set_topic_name(topic_name=topic_name)
          scheduled_message.content = send_request.message.content
          scheduled_message.sending_client = send_request.message.sending_client
          scheduled_message.stream = send_request.stream
          scheduled_message.realm = send_request.realm
          assert send_request.deliver_at is not None
          scheduled_message.scheduled_timestamp = send_request.deliver_at
          if send_request.delivery_type == "send_later":
              scheduled_message.delivery_type = ScheduledMessage.SEND_LATER
          elif send_request.delivery_type == "remind":
              scheduled_message.delivery_type = ScheduledMessage.REMIND
  
          scheduled_messages.append(scheduled_message)
  
      ScheduledMessage.objects.bulk_create(scheduled_messages)
      return [scheduled_message.id for scheduled_message in scheduled_messages]
  
  
  def build_message_send_dict(
      message: Message,
      stream: Optional[Stream] = None,
      local_id: Optional[str] = None,
      sender_queue_id: Optional[str] = None,
      realm: Optional[Realm] = None,
      widget_content_dict: Optional[Dict[str, Any]] = None,
      email_gateway: bool = False,
  ) -> SendMessageRequest:
      """Returns a dictionary that can be passed into do_send_messages.  In
      production, this is always called by check_message, but some
      testing code paths call it directly.
      """
      if realm is None:
          realm = message.sender.realm
  
      mention_data = MentionData(
          realm_id=realm.id,
          content=message.content,
      )
  
      if message.is_stream_message():
          stream_id = message.recipient.type_id
          stream_topic: Optional[StreamTopicTarget] = StreamTopicTarget(
              stream_id=stream_id,
              topic_name=message.topic_name(),
          )
      else:
          stream_topic = None
  
      info = get_recipient_info(
          realm_id=realm.id,
          recipient=message.recipient,
          sender_id=message.sender_id,
          stream_topic=stream_topic,
          possibly_mentioned_user_ids=mention_data.get_user_ids(),
          possible_wildcard_mention=mention_data.message_has_wildcards(),
      )
  
      # Render our message_dicts.
      assert message.rendered_content is None
  
      rendering_result = render_incoming_message(
          message,
          message.content,
          info["active_user_ids"],
          realm,
          mention_data=mention_data,
          email_gateway=email_gateway,
      )
      message.rendered_content = rendering_result.rendered_content
      message.rendered_content_version = markdown_version
      links_for_embed = rendering_result.links_for_preview
  
      mentioned_user_groups_map = get_user_group_mentions_data(
          mentioned_user_ids=rendering_result.mentions_user_ids,
          mentioned_user_group_ids=list(rendering_result.mentions_user_group_ids),
          mention_data=mention_data,
      )
  
      # For single user as well as user group mentions, we set the `mentioned`
      # flag on `UserMessage`
      for group_id in rendering_result.mentions_user_group_ids:
          members = mention_data.get_group_members(group_id)
          rendering_result.mentions_user_ids.update(members)
  
      # Only send data to Tornado about wildcard mentions if message
      # rendering determined the message had an actual wildcard
      # mention in it (and not e.g. wildcard mention syntax inside a
      # code block).
      if rendering_result.mentions_wildcard:
          wildcard_mention_user_ids = info["wildcard_mention_user_ids"]
      else:
          wildcard_mention_user_ids = set()
  
      """
      Once we have the actual list of mentioned ids from message
      rendering, we can patch in "default bots" (aka normal bots)
      who were directly mentioned in this message as eligible to
      get UserMessage rows.
      """
      mentioned_user_ids = rendering_result.mentions_user_ids
      default_bot_user_ids = info["default_bot_user_ids"]
      mentioned_bot_user_ids = default_bot_user_ids & mentioned_user_ids
      info["um_eligible_user_ids"] |= mentioned_bot_user_ids
  
      message_send_dict = SendMessageRequest(
          stream=stream,
          local_id=local_id,
          sender_queue_id=sender_queue_id,
          realm=realm,
          mention_data=mention_data,
          mentioned_user_groups_map=mentioned_user_groups_map,
          message=message,
          rendering_result=rendering_result,
          active_user_ids=info["active_user_ids"],
          online_push_user_ids=info["online_push_user_ids"],
          pm_mention_email_disabled_user_ids=info["pm_mention_email_disabled_user_ids"],
          pm_mention_push_disabled_user_ids=info["pm_mention_push_disabled_user_ids"],
          stream_push_user_ids=info["stream_push_user_ids"],
          stream_email_user_ids=info["stream_email_user_ids"],
          muted_sender_user_ids=info["muted_sender_user_ids"],
          um_eligible_user_ids=info["um_eligible_user_ids"],
          long_term_idle_user_ids=info["long_term_idle_user_ids"],
          default_bot_user_ids=info["default_bot_user_ids"],
          service_bot_tuples=info["service_bot_tuples"],
          wildcard_mention_user_ids=wildcard_mention_user_ids,
          links_for_embed=links_for_embed,
          widget_content=widget_content_dict,
      )
  
      return message_send_dict
  
  
  def do_send_messages(
      send_message_requests_maybe_none: Sequence[Optional[SendMessageRequest]],
      email_gateway: bool = False,
      mark_as_read: Sequence[int] = [],
  ) -> List[int]:
      """See
      https://zulip.readthedocs.io/en/latest/subsystems/sending-messages.html
      for high-level documentation on this subsystem.
      """
  
      # Filter out messages which didn't pass internal_prep_message properly
      send_message_requests = [
          send_request
          for send_request in send_message_requests_maybe_none
          if send_request is not None
      ]
  
      # Save the message receipts in the database
      user_message_flags: Dict[int, Dict[int, List[str]]] = defaultdict(dict)
      with transaction.atomic():
          Message.objects.bulk_create(send_request.message for send_request in send_message_requests)
  
          # Claim attachments in message
          for send_request in send_message_requests:
              if do_claim_attachments(
                  send_request.message, send_request.rendering_result.potential_attachment_path_ids
              ):
                  send_request.message.has_attachment = True
                  send_request.message.save(update_fields=["has_attachment"])
  
          ums: List[UserMessageLite] = []
          for send_request in send_message_requests:
              # Service bots (outgoing webhook bots and embedded bots) don't store UserMessage rows;
              # they will be processed later.
              mentioned_user_ids = send_request.rendering_result.mentions_user_ids
  
              # Extend the set with users who have muted the sender.
              mark_as_read_for_users = send_request.muted_sender_user_ids
              mark_as_read_for_users.update(mark_as_read)
  
              user_messages = create_user_messages(
                  message=send_request.message,
                  rendering_result=send_request.rendering_result,
                  um_eligible_user_ids=send_request.um_eligible_user_ids,
                  long_term_idle_user_ids=send_request.long_term_idle_user_ids,
                  stream_push_user_ids=send_request.stream_push_user_ids,
                  stream_email_user_ids=send_request.stream_email_user_ids,
                  mentioned_user_ids=mentioned_user_ids,
                  mark_as_read_for_users=mark_as_read_for_users,
              )
  
              for um in user_messages:
                  user_message_flags[send_request.message.id][um.user_profile_id] = um.flags_list()
  
              ums.extend(user_messages)
  
              send_request.message.service_queue_events = get_service_bot_events(
                  sender=send_request.message.sender,
                  service_bot_tuples=send_request.service_bot_tuples,
                  mentioned_user_ids=mentioned_user_ids,
                  active_user_ids=send_request.active_user_ids,
                  recipient_type=send_request.message.recipient.type,
              )
  
          bulk_insert_ums(ums)
  
          for send_request in send_message_requests:
              do_widget_post_save_actions(send_request)
  
      # This next loop is responsible for notifying other parts of the
      # Zulip system about the messages we just committed to the database:
      # * Notifying clients via send_event
      # * Triggering outgoing webhooks via the service event queue.
      # * Updating the `first_message_id` field for streams without any message history.
      # * Implementing the Welcome Bot reply hack
      # * Adding links to the embed_links queue for open graph processing.
      for send_request in send_message_requests:
          realm_id: Optional[int] = None
          if send_request.message.is_stream_message():
              if send_request.stream is None:
                  stream_id = send_request.message.recipient.type_id
                  send_request.stream = Stream.objects.select_related().get(id=stream_id)
              # assert needed because stubs for django are missing
              assert send_request.stream is not None
              realm_id = send_request.stream.realm_id
  
          # Deliver events to the real-time push system, as well as
          # enqueuing any additional processing triggered by the message.
          wide_message_dict = MessageDict.wide_dict(send_request.message, realm_id)
  
          user_flags = user_message_flags.get(send_request.message.id, {})
  
          """
          TODO:  We may want to limit user_ids to only those users who have
                 UserMessage rows, if only for minor performance reasons.
  
                 For now we queue events for all subscribers/sendees of the
                 message, since downstream code may still do notifications
                 that don't require UserMessage rows.
  
                 Our automated tests have gotten better on this codepath,
                 but we may have coverage gaps, so we should be careful
                 about changing the next line.
          """
          user_ids = send_request.active_user_ids | set(user_flags.keys())
          sender_id = send_request.message.sender_id
  
          # We make sure the sender is listed first in the `users` list;
          # this results in the sender receiving the message first if
          # there are thousands of recipients, decreasing perceived latency.
          if sender_id in user_ids:
              user_list = [sender_id] + list(user_ids - {sender_id})
          else:
              user_list = list(user_ids)
  
          class UserData(TypedDict):
              id: int
              flags: List[str]
              mentioned_user_group_id: Optional[int]
  
          users: List[UserData] = []
          for user_id in user_list:
              flags = user_flags.get(user_id, [])
              user_data: UserData = dict(id=user_id, flags=flags, mentioned_user_group_id=None)
  
              if user_id in send_request.mentioned_user_groups_map:
                  user_data["mentioned_user_group_id"] = send_request.mentioned_user_groups_map[
                      user_id
                  ]
  
              users.append(user_data)
  
          sender = send_request.message.sender
          message_type = wide_message_dict["type"]
          active_users_data = [
              ActivePresenceIdleUserData(
                  alerted="has_alert_word" in user_flags.get(user_id, []),
                  notifications_data=UserMessageNotificationsData.from_user_id_sets(
                      user_id=user_id,
                      flags=user_flags.get(user_id, []),
                      private_message=(message_type == "private"),
                      online_push_user_ids=send_request.online_push_user_ids,
                      pm_mention_push_disabled_user_ids=send_request.pm_mention_push_disabled_user_ids,
                      pm_mention_email_disabled_user_ids=send_request.pm_mention_email_disabled_user_ids,
                      stream_push_user_ids=send_request.stream_push_user_ids,
                      stream_email_user_ids=send_request.stream_email_user_ids,
                      wildcard_mention_user_ids=send_request.wildcard_mention_user_ids,
                      muted_sender_user_ids=send_request.muted_sender_user_ids,
                  ),
              )
              for user_id in send_request.active_user_ids
          ]
  
          presence_idle_user_ids = get_active_presence_idle_user_ids(
              realm=sender.realm,
              sender_id=sender.id,
              active_users_data=active_users_data,
          )
  
          event = dict(
              type="message",
              message=send_request.message.id,
              message_dict=wide_message_dict,
              presence_idle_user_ids=presence_idle_user_ids,
              online_push_user_ids=list(send_request.online_push_user_ids),
              pm_mention_push_disabled_user_ids=list(send_request.pm_mention_push_disabled_user_ids),
              pm_mention_email_disabled_user_ids=list(
                  send_request.pm_mention_email_disabled_user_ids
              ),
              stream_push_user_ids=list(send_request.stream_push_user_ids),
              stream_email_user_ids=list(send_request.stream_email_user_ids),
              wildcard_mention_user_ids=list(send_request.wildcard_mention_user_ids),
              muted_sender_user_ids=list(send_request.muted_sender_user_ids),
          )
  
          if send_request.message.is_stream_message():
              # Note: This is where authorization for single-stream
              # get_updates happens! We only attach stream data to the
              # notify new_message request if it's a public stream,
              # ensuring that in the tornado server, non-public stream
              # messages are only associated to their subscribed users.
  
              # assert needed because stubs for django are missing
              assert send_request.stream is not None
              if send_request.stream.is_public():
                  event["realm_id"] = send_request.stream.realm_id
                  event["stream_name"] = send_request.stream.name
              if send_request.stream.invite_only:
                  event["invite_only"] = True
              if send_request.stream.first_message_id is None:
                  send_request.stream.first_message_id = send_request.message.id
                  send_request.stream.save(update_fields=["first_message_id"])
          if send_request.local_id is not None:
              event["local_id"] = send_request.local_id
          if send_request.sender_queue_id is not None:
              event["sender_queue_id"] = send_request.sender_queue_id
          send_event(send_request.realm, event, users)
  
          if send_request.links_for_embed:
              event_data = {
                  "message_id": send_request.message.id,
                  "message_content": send_request.message.content,
                  "message_realm_id": send_request.realm.id,
                  "urls": list(send_request.links_for_embed),
              }
              queue_json_publish("embed_links", event_data)
  
          if send_request.message.recipient.type == Recipient.PERSONAL:
              welcome_bot_id = get_system_bot(
                  settings.WELCOME_BOT, send_request.message.sender.realm_id
              ).id
              if (
                  welcome_bot_id in send_request.active_user_ids
                  and welcome_bot_id != send_request.message.sender_id
              ):
                  from zerver.lib.onboarding import send_welcome_bot_response
  
                  send_welcome_bot_response(send_request)
  
          for queue_name, events in send_request.message.service_queue_events.items():
              for event in events:
                  queue_json_publish(
                      queue_name,
                      {
                          "message": wide_message_dict,
                          "trigger": event["trigger"],
                          "user_profile_id": event["user_profile_id"],
                      },
                  )
  
      return [send_request.message.id for send_request in send_message_requests]
  
  
  class UserMessageLite:
      """
      The Django ORM is too slow for bulk operations.  This class
      is optimized for the simple use case of inserting a bunch of
      rows into zerver_usermessage.
      """
  
      def __init__(self, user_profile_id: int, message_id: int, flags: int) -> None:
          self.user_profile_id = user_profile_id
          self.message_id = message_id
          self.flags = flags
  
      def flags_list(self) -> List[str]:
          return UserMessage.flags_list_for_flags(self.flags)
  
  
  def create_user_messages(
      message: Message,
      rendering_result: MessageRenderingResult,
      um_eligible_user_ids: AbstractSet[int],
      long_term_idle_user_ids: AbstractSet[int],
      stream_push_user_ids: AbstractSet[int],
      stream_email_user_ids: AbstractSet[int],
      mentioned_user_ids: AbstractSet[int],
      mark_as_read_for_users: Set[int],
  ) -> List[UserMessageLite]:
      # These properties on the Message are set via
      # render_markdown by code in the Markdown inline patterns
      ids_with_alert_words = rendering_result.user_ids_with_alert_words
      sender_id = message.sender.id
      is_stream_message = message.is_stream_message()
  
      base_flags = 0
      if rendering_result.mentions_wildcard:
          base_flags |= UserMessage.flags.wildcard_mentioned
      if message.recipient.type in [Recipient.HUDDLE, Recipient.PERSONAL]:
          base_flags |= UserMessage.flags.is_private
  
      # For long_term_idle (aka soft-deactivated) users, we are allowed
      # to optimize by lazily not creating UserMessage rows that would
      # have the default 0 flag set (since the soft-reactivation logic
      # knows how to create those when the user comes back).  We need to
      # create the UserMessage rows for these long_term_idle users
      # non-lazily in a few cases:
      #
      # * There are nonzero flags (e.g. the user was mentioned), since
      #   that case is rare and this saves a lot of complexity in
      #   soft-reactivation.
      #
      # * If the user is going to be notified (e.g. they get push/email
      #   notifications for every message on a stream), since in that
      #   case the notifications code will call `access_message` on the
      #   message to re-verify permissions, and for private streams,
      #   will get an error if the UserMessage row doesn't exist yet.
      #
      # See https://zulip.readthedocs.io/en/latest/subsystems/sending-messages.html#soft-deactivation
      # for details on this system.
      user_messages = []
      for user_profile_id in um_eligible_user_ids:
          flags = base_flags
          if (
              user_profile_id == sender_id and message.sent_by_human()
          ) or user_profile_id in mark_as_read_for_users:
              flags |= UserMessage.flags.read
          if user_profile_id in mentioned_user_ids:
              flags |= UserMessage.flags.mentioned
          if user_profile_id in ids_with_alert_words:
              flags |= UserMessage.flags.has_alert_word
  
          if (
              user_profile_id in long_term_idle_user_ids
              and user_profile_id not in stream_push_user_ids
              and user_profile_id not in stream_email_user_ids
              and is_stream_message
              and int(flags) == 0
          ):
              continue
  
          um = UserMessageLite(
              user_profile_id=user_profile_id,
              message_id=message.id,
              flags=flags,
          )
          user_messages.append(um)
  
      return user_messages
  
  
  def bulk_insert_ums(ums: List[UserMessageLite]) -> None:
      """
      Doing bulk inserts this way is much faster than using Django,
      since we don't have any ORM overhead.  Profiling with 1000
      users shows a speedup of 0.436 -> 0.027 seconds, so we're
      talking about a 15x speedup.
      """
      if not ums:
          return
  
      vals = [(um.user_profile_id, um.message_id, um.flags) for um in ums]
      query = SQL(
          """
          INSERT into
              zerver_usermessage (user_profile_id, message_id, flags)
          VALUES %s
      """
      )
  
      with connection.cursor() as cursor:
          execute_values(cursor.cursor, query, vals)
  
  
  def verify_submessage_sender(
      *,
      message_id: int,
      message_sender_id: int,
      submessage_sender_id: int,
  ) -> None:
      """Even though our submessage architecture is geared toward
      collaboration among all message readers, we still enforce
      the the first person to attach a submessage to the message
      must be the original sender of the message.
      """
  
      if message_sender_id == submessage_sender_id:
          return
  
      if SubMessage.objects.filter(
          message_id=message_id,
          sender_id=message_sender_id,
      ).exists():
          return
  
      raise JsonableError(_("You cannot attach a submessage to this message."))
  
  
  def do_add_submessage(
      realm: Realm,
      sender_id: int,
      message_id: int,
      msg_type: str,
      content: str,
  ) -> None:
      """Should be called while holding a SELECT FOR UPDATE lock
      (e.g. via access_message(..., lock_message=True)) on the
      Message row, to prevent race conditions.
      """
      submessage = SubMessage(
          sender_id=sender_id,
          message_id=message_id,
          msg_type=msg_type,
          content=content,
      )
      submessage.save()
  
      event = dict(
          type="submessage",
          msg_type=msg_type,
          message_id=message_id,
          submessage_id=submessage.id,
          sender_id=sender_id,
          content=content,
      )
      ums = UserMessage.objects.filter(message_id=message_id)
      target_user_ids = [um.user_profile_id for um in ums]
  
      transaction.on_commit(lambda: send_event(realm, event, target_user_ids))
  
  
  def notify_reaction_update(
      user_profile: UserProfile, message: Message, reaction: Reaction, op: str
  ) -> None:
      user_dict = {
          "user_id": user_profile.id,
          "email": user_profile.email,
          "full_name": user_profile.full_name,
      }
  
      event: Dict[str, Any] = {
          "type": "reaction",
          "op": op,
          "user_id": user_profile.id,
          # TODO: We plan to remove this redundant user_dict object once
          # clients are updated to support accessing use user_id.  See
          # https://github.com/zulip/zulip/pull/14711 for details.
          "user": user_dict,
          "message_id": message.id,
          "emoji_name": reaction.emoji_name,
          "emoji_code": reaction.emoji_code,
          "reaction_type": reaction.reaction_type,
      }
  
      # Update the cached message since new reaction is added.
      update_to_dict_cache([message])
  
      # Recipients for message update events, including reactions, are
      # everyone who got the original message, plus subscribers of
      # streams with the access to stream's full history.
      #
      # This means reactions won't live-update in preview narrows for a
      # stream the user isn't yet subscribed to; this is the right
      # performance tradeoff to avoid sending every reaction to public
      # stream messages to all users.
      #
      # To ensure that reactions do live-update for any user who has
      # actually participated in reacting to a message, we add a
      # "historical" UserMessage row for any user who reacts to message,
      # subscribing them to future notifications, even if they are not
      # subscribed to the stream.
      user_ids = set(
          UserMessage.objects.filter(message=message.id).values_list("user_profile_id", flat=True)
      )
      if message.recipient.type == Recipient.STREAM:
          stream_id = message.recipient.type_id
          stream = Stream.objects.get(id=stream_id)
          user_ids |= subscriber_ids_with_stream_history_access(stream)
  
      transaction.on_commit(lambda: send_event(user_profile.realm, event, list(user_ids)))
  
  
  def do_add_reaction(
      user_profile: UserProfile,
      message: Message,
      emoji_name: str,
      emoji_code: str,
      reaction_type: str,
  ) -> None:
      """Should be called while holding a SELECT FOR UPDATE lock
      (e.g. via access_message(..., lock_message=True)) on the
      Message row, to prevent race conditions.
      """
  
      reaction = Reaction(
          user_profile=user_profile,
          message=message,
          emoji_name=emoji_name,
          emoji_code=emoji_code,
          reaction_type=reaction_type,
      )
  
      reaction.save()
  
      notify_reaction_update(user_profile, message, reaction, "add")
  
  
  def check_add_reaction(
      user_profile: UserProfile,
      message_id: int,
      emoji_name: str,
      emoji_code: Optional[str],
      reaction_type: Optional[str],
  ) -> None:
      message, user_message = access_message(user_profile, message_id, lock_message=True)
  
      if emoji_code is None:
          # The emoji_code argument is only required for rare corner
          # cases discussed in the long block comment below.  For simple
          # API clients, we allow specifying just the name, and just
          # look up the code using the current name->code mapping.
          emoji_code = emoji_name_to_emoji_code(message.sender.realm, emoji_name)[0]
  
      if reaction_type is None:
          reaction_type = emoji_name_to_emoji_code(message.sender.realm, emoji_name)[1]
  
      if Reaction.objects.filter(
          user_profile=user_profile,
          message=message,
          emoji_code=emoji_code,
          reaction_type=reaction_type,
      ).exists():
          raise JsonableError(_("Reaction already exists."))
  
      query = Reaction.objects.filter(
          message=message, emoji_code=emoji_code, reaction_type=reaction_type
      )
      if query.exists():
          # If another user has already reacted to this message with
          # same emoji code, we treat the new reaction as a vote for the
          # existing reaction.  So the emoji name used by that earlier
          # reaction takes precedence over whatever was passed in this
          # request.  This is necessary to avoid a message having 2
          # "different" emoji reactions with the same emoji code (and
          # thus same image) on the same message, which looks ugly.
          #
          # In this "voting for an existing reaction" case, we shouldn't
          # check whether the emoji code and emoji name match, since
          # it's possible that the (emoji_type, emoji_name, emoji_code)
          # triple for this existing rection xmay not pass validation
          # now (e.g. because it is for a realm emoji that has been
          # since deactivated).  We still want to allow users to add a
          # vote any old reaction they see in the UI even if that is a
          # deactivated custom emoji, so we just use the emoji name from
          # the existing reaction with no further validation.
          reaction = query.first()
          assert reaction is not None
          emoji_name = reaction.emoji_name
      else:
          # Otherwise, use the name provided in this request, but verify
          # it is valid in the user's realm (e.g. not a deactivated
          # realm emoji).
          check_emoji_request(user_profile.realm, emoji_name, emoji_code, reaction_type)
  
      if user_message is None:
          # Users can see and react to messages sent to streams they
          # were not a subscriber to; in order to receive events for
          # those, we give the user a `historical` UserMessage objects
          # for the message.  This is the same trick we use for starring
          # messages.
          UserMessage.objects.create(
              user_profile=user_profile,
              message=message,
              flags=UserMessage.flags.historical | UserMessage.flags.read,
          )
  
      do_add_reaction(user_profile, message, emoji_name, emoji_code, reaction_type)
  
  
  def do_remove_reaction(
      user_profile: UserProfile, message: Message, emoji_code: str, reaction_type: str
  ) -> None:
      """Should be called while holding a SELECT FOR UPDATE lock
      (e.g. via access_message(..., lock_message=True)) on the
      Message row, to prevent race conditions.
      """
      reaction = Reaction.objects.filter(
          user_profile=user_profile,
          message=message,
          emoji_code=emoji_code,
          reaction_type=reaction_type,
      ).get()
      reaction.delete()
  
      notify_reaction_update(user_profile, message, reaction, "remove")
  
  
  def do_send_typing_notification(
      realm: Realm, sender: UserProfile, recipient_user_profiles: List[UserProfile], operator: str
  ) -> None:
  
      sender_dict = {"user_id": sender.id, "email": sender.email}
  
      # Include a list of recipients in the event body to help identify where the typing is happening
      recipient_dicts = [
          {"user_id": profile.id, "email": profile.email} for profile in recipient_user_profiles
      ]
      event = dict(
          type="typing",
          message_type="private",
          op=operator,
          sender=sender_dict,
          recipients=recipient_dicts,
      )
  
      # Only deliver the notification to active user recipients
      user_ids_to_notify = [user.id for user in recipient_user_profiles if user.is_active]
  
      send_event(realm, event, user_ids_to_notify)
  
  
  # check_send_typing_notification:
  # Checks the typing notification and sends it
  def check_send_typing_notification(sender: UserProfile, user_ids: List[int], operator: str) -> None:
      realm = sender.realm
  
      if sender.id not in user_ids:
          user_ids.append(sender.id)
  
      # If any of the user_ids being sent in are invalid, we will
      # just reject the whole request, since a partial list of user_ids
      # can create confusion related to huddles.  Plus it's a good
      # sign that a client is confused (or possibly even malicious) if
      # we get bad user_ids.
      user_profiles = []
      for user_id in user_ids:
          try:
              # We include cross-bot realms as possible recipients,
              # so that clients can know which huddle conversation
              # is relevant here.
              user_profile = get_user_by_id_in_realm_including_cross_realm(user_id, sender.realm)
          except UserProfile.DoesNotExist:
              raise JsonableError(_("Invalid user ID {}").format(user_id))
          user_profiles.append(user_profile)
  
      do_send_typing_notification(
          realm=realm,
          sender=sender,
          recipient_user_profiles=user_profiles,
          operator=operator,
      )
  
  
  def do_send_stream_typing_notification(
      sender: UserProfile, operator: str, stream: Stream, topic: str
  ) -> None:
  
      sender_dict = {"user_id": sender.id, "email": sender.email}
  
      event = dict(
          type="typing",
          message_type="stream",
          op=operator,
          sender=sender_dict,
          stream_id=stream.id,
          topic=topic,
      )
  
      user_ids_to_notify = get_user_ids_for_streams({stream.id})[stream.id]
  
      send_event(sender.realm, event, user_ids_to_notify)
  
  
  def ensure_stream(
      realm: Realm,
      stream_name: str,
      invite_only: bool = False,
      stream_description: str = "",
      *,
      acting_user: Optional[UserProfile],
  ) -> Stream:
      return create_stream_if_needed(
          realm,
          stream_name,
          invite_only=invite_only,
          stream_description=stream_description,
          acting_user=acting_user,
      )[0]
  
  
  def get_recipient_from_user_profiles(
      recipient_profiles: Sequence[UserProfile],
      forwarded_mirror_message: bool,
      forwarder_user_profile: Optional[UserProfile],
      sender: UserProfile,
  ) -> Recipient:
  
      # Avoid mutating the passed in list of recipient_profiles.
      recipient_profiles_map = {user_profile.id: user_profile for user_profile in recipient_profiles}
  
      if forwarded_mirror_message:
          # In our mirroring integrations with some third-party
          # protocols, bots subscribed to the third-party protocol
          # forward to Zulip messages that they received in the
          # third-party service.  The permissions model for that
          # forwarding is that users can only submit to Zulip private
          # messages they personally received, and here we do the check
          # for whether forwarder_user_profile is among the private
          # message recipients of the message.
          assert forwarder_user_profile is not None
          if forwarder_user_profile.id not in recipient_profiles_map:
              raise ValidationError(_("User not authorized for this query"))
  
      # If the private message is just between the sender and
      # another person, force it to be a personal internally
      if len(recipient_profiles_map) == 2 and sender.id in recipient_profiles_map:
          del recipient_profiles_map[sender.id]
  
      assert recipient_profiles_map
      if len(recipient_profiles_map) == 1:
          [user_profile] = recipient_profiles_map.values()
          return user_profile.recipient
  
      # Otherwise, we need a huddle.  Make sure the sender is included in huddle messages
      recipient_profiles_map[sender.id] = sender
  
      user_ids = set(recipient_profiles_map)
      return get_huddle_recipient(user_ids)
  
  
  def validate_recipient_user_profiles(
      user_profiles: Sequence[UserProfile], sender: UserProfile, allow_deactivated: bool = False
  ) -> Sequence[UserProfile]:
      recipient_profiles_map: Dict[int, UserProfile] = {}
  
      # We exempt cross-realm bots from the check that all the recipients
      # are in the same realm.
      realms = set()
      if not is_cross_realm_bot_email(sender.email):
          realms.add(sender.realm_id)
  
      for user_profile in user_profiles:
          if (
              not user_profile.is_active
              and not user_profile.is_mirror_dummy
              and not allow_deactivated
          ) or user_profile.realm.deactivated:
              raise ValidationError(
                  _("'{email}' is no longer using Zulip.").format(email=user_profile.email)
              )
          recipient_profiles_map[user_profile.id] = user_profile
          if not is_cross_realm_bot_email(user_profile.email):
              realms.add(user_profile.realm_id)
  
      if len(realms) > 1:
          raise ValidationError(_("You can't send private messages outside of your organization."))
  
      return list(recipient_profiles_map.values())
  
  
  def recipient_for_user_profiles(
      user_profiles: Sequence[UserProfile],
      forwarded_mirror_message: bool,
      forwarder_user_profile: Optional[UserProfile],
      sender: UserProfile,
      allow_deactivated: bool = False,
  ) -> Recipient:
  
      recipient_profiles = validate_recipient_user_profiles(
          user_profiles, sender, allow_deactivated=allow_deactivated
      )
  
      return get_recipient_from_user_profiles(
          recipient_profiles, forwarded_mirror_message, forwarder_user_profile, sender
      )
  
  
  def already_sent_mirrored_message_id(message: Message) -> Optional[int]:
      if message.recipient.type == Recipient.HUDDLE:
          # For huddle messages, we use a 10-second window because the
          # timestamps aren't guaranteed to actually match between two
          # copies of the same message.
          time_window = datetime.timedelta(seconds=10)
      else:
          time_window = datetime.timedelta(seconds=0)
  
      query = Message.objects.filter(
          sender=message.sender,
          recipient=message.recipient,
          content=message.content,
          sending_client=message.sending_client,
          date_sent__gte=message.date_sent - time_window,
          date_sent__lte=message.date_sent + time_window,
      )
  
      messages = filter_by_exact_message_topic(
          query=query,
          message=message,
      )
  
      if messages.exists():
          return messages[0].id
      return None
  
  
  def extract_stream_indicator(s: str) -> Union[str, int]:
      # Users can pass stream name as either an id or a name,
      # and if they choose to pass a name, they may JSON encode
      # it for legacy reasons.
  
      try:
          data = orjson.loads(s)
      except orjson.JSONDecodeError:
          # If there was no JSON encoding, then we just
          # have a raw stream name.
          return s
  
      # We should stop supporting this odd use case
      # once we improve our documentation.
      if isinstance(data, list):
          if len(data) != 1:  # nocoverage
              raise JsonableError(_("Expected exactly one stream"))
          data = data[0]
  
      if isinstance(data, str):
          # We had a JSON-encoded stream name.
          return data
  
      if isinstance(data, int):
          # We had a stream id.
          return data
  
      raise JsonableError(_("Invalid data type for stream"))
  
  
  def extract_private_recipients(s: str) -> Union[List[str], List[int]]:
      # We try to accept multiple incoming formats for recipients.
      # See test_extract_recipients() for examples of what we allow.
  
      try:
          data = orjson.loads(s)
      except orjson.JSONDecodeError:
          data = s
  
      if isinstance(data, str):
          data = data.split(",")
  
      if not isinstance(data, list):
          raise JsonableError(_("Invalid data type for recipients"))
  
      if not data:
          # We don't complain about empty message recipients here
          return data
  
      if isinstance(data[0], str):
          return get_validated_emails(data)
  
      if not isinstance(data[0], int):
          raise JsonableError(_("Invalid data type for recipients"))
  
      return get_validated_user_ids(data)
  
  
  def get_validated_user_ids(user_ids: Collection[int]) -> List[int]:
      for user_id in user_ids:
          if not isinstance(user_id, int):
              raise JsonableError(_("Recipient lists may contain emails or user IDs, but not both."))
  
      return list(set(user_ids))
  
  
  def get_validated_emails(emails: Collection[str]) -> List[str]:
      for email in emails:
          if not isinstance(email, str):
              raise JsonableError(_("Recipient lists may contain emails or user IDs, but not both."))
  
      return list(filter(bool, {email.strip() for email in emails}))
  
  
  def check_send_stream_message(
      sender: UserProfile,
      client: Client,
      stream_name: str,
      topic: str,
      body: str,
      realm: Optional[Realm] = None,
  ) -> int:
      addressee = Addressee.for_stream_name(stream_name, topic)
      message = check_message(sender, client, addressee, body, realm)
  
      return do_send_messages([message])[0]
  
  
  def check_send_stream_message_by_id(
      sender: UserProfile,
      client: Client,
      stream_id: int,
      topic: str,
      body: str,
      realm: Optional[Realm] = None,
  ) -> int:
      addressee = Addressee.for_stream_id(stream_id, topic)
      message = check_message(sender, client, addressee, body, realm)
  
      return do_send_messages([message])[0]
  
  
  def check_send_private_message(
      sender: UserProfile, client: Client, receiving_user: UserProfile, body: str
  ) -> int:
      addressee = Addressee.for_user_profile(receiving_user)
      message = check_message(sender, client, addressee, body)
  
      return do_send_messages([message])[0]
  
  
  # check_send_message:
  # Returns the id of the sent message.  Has same argspec as check_message.
  def check_send_message(
      sender: UserProfile,
      client: Client,
      message_type_name: str,
      message_to: Union[Sequence[int], Sequence[str]],
      topic_name: Optional[str],
      message_content: str,
      realm: Optional[Realm] = None,
      forged: bool = False,
      forged_timestamp: Optional[float] = None,
      forwarder_user_profile: Optional[UserProfile] = None,
      local_id: Optional[str] = None,
      sender_queue_id: Optional[str] = None,
      widget_content: Optional[str] = None,
      *,
      skip_stream_access_check: bool = False,
  ) -> int:
  
      addressee = Addressee.legacy_build(sender, message_type_name, message_to, topic_name)
      try:
          message = check_message(
              sender,
              client,
              addressee,
              message_content,
              realm,
              forged,
              forged_timestamp,
              forwarder_user_profile,
              local_id,
              sender_queue_id,
              widget_content,
              skip_stream_access_check=skip_stream_access_check,
          )
      except ZephyrMessageAlreadySentException as e:
          return e.message_id
      return do_send_messages([message])[0]
  
  
  def check_schedule_message(
      sender: UserProfile,
      client: Client,
      message_type_name: str,
      message_to: Union[Sequence[str], Sequence[int]],
      topic_name: Optional[str],
      message_content: str,
      delivery_type: str,
      deliver_at: datetime.datetime,
      realm: Optional[Realm] = None,
      forwarder_user_profile: Optional[UserProfile] = None,
  ) -> int:
      addressee = Addressee.legacy_build(sender, message_type_name, message_to, topic_name)
  
      send_request = check_message(
          sender,
          client,
          addressee,
          message_content,
          realm=realm,
          forwarder_user_profile=forwarder_user_profile,
      )
      send_request.deliver_at = deliver_at
      send_request.delivery_type = delivery_type
  
      recipient = send_request.message.recipient
      if delivery_type == "remind" and (
          recipient.type != Recipient.STREAM and recipient.type_id != sender.id
      ):
          raise JsonableError(_("Reminders can only be set for streams."))
  
      return do_schedule_messages([send_request])[0]
  
  
  def validate_message_edit_payload(
      message: Message,
      stream_id: Optional[int],
      topic_name: Optional[str],
      propagate_mode: Optional[str],
      content: Optional[str],
  ) -> None:
      """
      Checks that the data sent is well-formed. Does not handle editability, permissions etc.
      """
      if topic_name is None and content is None and stream_id is None:
          raise JsonableError(_("Nothing to change"))
  
      if not message.is_stream_message():
          if stream_id is not None:
              raise JsonableError(_("Private messages cannot be moved to streams."))
          if topic_name is not None:
              raise JsonableError(_("Private messages cannot have topics."))
  
      if propagate_mode != "change_one" and topic_name is None and stream_id is None:
          raise JsonableError(_("Invalid propagate_mode without topic edit"))
  
      if topic_name == "":
          raise JsonableError(_("Topic can't be empty"))
  
      if stream_id is not None and content is not None:
          raise JsonableError(_("Cannot change message content while changing stream"))
  
      # Right now, we prevent users from editing widgets.
      if content is not None and is_widget_message(message):
          raise JsonableError(_("Widgets cannot be edited."))
  
  
  def can_edit_content_or_topic(
      message: Message,
      user_profile: UserProfile,
      is_no_topic_msg: bool,
      content: Optional[str] = None,
      topic_name: Optional[str] = None,
  ) -> bool:
      # You have permission to edit the message (both content and topic) if you sent it.
      if message.sender_id == user_profile.id:
          return True
  
      # You cannot edit the content of message sent by someone else.
      if content is not None:
          return False
  
      assert topic_name is not None
  
      # The following cases are the various reasons a user might be
      # allowed to edit topics.
  
      # We allow anyone to edit (no topic) messages to help tend them.
      if is_no_topic_msg:
          return True
  
      # The can_edit_topic_of_any_message helper returns whether the user can edit the topic
      # or not based on edit_topic_policy setting and the user's role.
      if user_profile.can_edit_topic_of_any_message():
          return True
  
      return False
  
  
  def check_update_message(
      user_profile: UserProfile,
      message_id: int,
      stream_id: Optional[int] = None,
      topic_name: Optional[str] = None,
      propagate_mode: str = "change_one",
      send_notification_to_old_thread: bool = True,
      send_notification_to_new_thread: bool = True,
      content: Optional[str] = None,
  ) -> int:
      """This will update a message given the message id and user profile.
      It checks whether the user profile has the permission to edit the message
      and raises a JsonableError if otherwise.
      It returns the number changed.
      """
      message, ignored_user_message = access_message(user_profile, message_id)
  
      if not user_profile.realm.allow_message_editing:
          raise JsonableError(_("Your organization has turned off message editing"))
  
      # The zerver/views/message_edit.py callpoint already strips this
      # via REQ_topic; so we can delete this line if we arrange a
      # contract where future callers in the embedded bots system strip
      # use REQ_topic as well (or otherwise are guaranteed to strip input).
      if topic_name is not None:
          topic_name = topic_name.strip()
          if topic_name == message.topic_name():
              topic_name = None
  
      validate_message_edit_payload(message, stream_id, topic_name, propagate_mode, content)
  
      is_no_topic_msg = message.topic_name() == "(no topic)"
  
      if content is not None or topic_name is not None:
          if not can_edit_content_or_topic(
              message, user_profile, is_no_topic_msg, content, topic_name
          ):
              raise JsonableError(_("You don't have permission to edit this message"))
  
      # If there is a change to the content, check that it hasn't been too long
      # Allow an extra 20 seconds since we potentially allow editing 15 seconds
      # past the limit, and in case there are network issues, etc. The 15 comes
      # from (min_seconds_to_edit + seconds_left_buffer) in message_edit.js; if
      # you change this value also change those two parameters in message_edit.js.
      edit_limit_buffer = 20
      if content is not None and user_profile.realm.message_content_edit_limit_seconds > 0:
          deadline_seconds = user_profile.realm.message_content_edit_limit_seconds + edit_limit_buffer
          if (timezone_now() - message.date_sent) > datetime.timedelta(seconds=deadline_seconds):
              raise JsonableError(_("The time limit for editing this message has passed"))
  
      # If there is a change to the topic, check that the user is allowed to
      # edit it and that it has not been too long. If this is not the user who
      # sent the message, they are not the admin, and the time limit for editing
      # topics is passed, raise an error.
      if (
          topic_name is not None
          and message.sender != user_profile
          and not user_profile.is_realm_admin
          and not user_profile.is_moderator
          and not is_no_topic_msg
      ):
          deadline_seconds = Realm.DEFAULT_COMMUNITY_TOPIC_EDITING_LIMIT_SECONDS + edit_limit_buffer
          if (timezone_now() - message.date_sent) > datetime.timedelta(seconds=deadline_seconds):
              raise JsonableError(_("The time limit for editing this message's topic has passed"))
  
      rendering_result = None
      links_for_embed: Set[str] = set()
      prior_mention_user_ids: Set[int] = set()
      mention_data: Optional[MentionData] = None
      if content is not None:
          if content.rstrip() == "":
              content = "(deleted)"
          content = normalize_body(content)
  
          mention_data = MentionData(
              realm_id=user_profile.realm.id,
              content=content,
          )
          user_info = get_user_info_for_message_updates(message.id)
          prior_mention_user_ids = user_info["mention_user_ids"]
  
          # We render the message using the current user's realm; since
          # the cross-realm bots never edit messages, this should be
          # always correct.
          # Note: If rendering fails, the called code will raise a JsonableError.
          rendering_result = render_incoming_message(
              message,
              content,
              user_info["message_user_ids"],
              user_profile.realm,
              mention_data=mention_data,
          )
          links_for_embed |= rendering_result.links_for_preview
  
      new_stream = None
      number_changed = 0
  
      if stream_id is not None:
          assert message.is_stream_message()
          if not user_profile.can_move_messages_between_streams():
              raise JsonableError(_("You don't have permission to move this message"))
          try:
              access_stream_by_id(user_profile, message.recipient.type_id)
          except JsonableError:
              raise JsonableError(
                  _(
                      "You don't have permission to move this message due to missing access to its stream"
                  )
              )
  
          new_stream = access_stream_by_id(user_profile, stream_id, require_active=True)[0]
          check_stream_access_based_on_stream_post_policy(user_profile, new_stream)
  
      number_changed = do_update_message(
          user_profile,
          message,
          new_stream,
          topic_name,
          propagate_mode,
          send_notification_to_old_thread,
          send_notification_to_new_thread,
          content,
          rendering_result,
          prior_mention_user_ids,
          mention_data,
      )
  
      if links_for_embed:
          event_data = {
              "message_id": message.id,
              "message_content": message.content,
              # The choice of `user_profile.realm_id` rather than
              # `sender.realm_id` must match the decision made in the
              # `render_incoming_message` call earlier in this function.
              "message_realm_id": user_profile.realm_id,
              "urls": list(links_for_embed),
          }
          queue_json_publish("embed_links", event_data)
  
      return number_changed
  
  
  def check_default_stream_group_name(group_name: str) -> None:
      if group_name.strip() == "":
          raise JsonableError(_("Invalid default stream group name '{}'").format(group_name))
      if len(group_name) > DefaultStreamGroup.MAX_NAME_LENGTH:
          raise JsonableError(
              _("Default stream group name too long (limit: {} characters)").format(
                  DefaultStreamGroup.MAX_NAME_LENGTH,
              )
          )
      for i in group_name:
          if ord(i) == 0:
              raise JsonableError(
                  _("Default stream group name '{}' contains NULL (0x00) characters.").format(
                      group_name,
                  )
              )
  
  
  def send_rate_limited_pm_notification_to_bot_owner(
      sender: UserProfile, realm: Realm, content: str
  ) -> None:
      """
      Sends a PM error notification to a bot's owner if one hasn't already
      been sent in the last 5 minutes.
      """
      if sender.realm.is_zephyr_mirror_realm or sender.realm.deactivated:
          return
  
      if not sender.is_bot or sender.bot_owner is None:
          return
  
      # Don't send these notifications for cross-realm bot messages
      # (e.g. from EMAIL_GATEWAY_BOT) since the owner for
      # EMAIL_GATEWAY_BOT is probably the server administrator, not
      # the owner of the bot who could potentially fix the problem.
      if sender.realm != realm:
          return
  
      # We warn the user once every 5 minutes to avoid a flood of
      # PMs on a misconfigured integration, re-using the
      # UserProfile.last_reminder field, which is not used for bots.
      last_reminder = sender.last_reminder
      waitperiod = datetime.timedelta(minutes=UserProfile.BOT_OWNER_STREAM_ALERT_WAITPERIOD)
      if last_reminder and timezone_now() - last_reminder <= waitperiod:
          return
  
      internal_send_private_message(
          get_system_bot(settings.NOTIFICATION_BOT, sender.bot_owner.realm_id),
          sender.bot_owner,
          content,
      )
  
      sender.last_reminder = timezone_now()
      sender.save(update_fields=["last_reminder"])
  
  
  def send_pm_if_empty_stream(
      stream: Optional[Stream],
      realm: Realm,
      sender: UserProfile,
      stream_name: Optional[str] = None,
      stream_id: Optional[int] = None,
  ) -> None:
      """If a bot sends a message to a stream that doesn't exist or has no
      subscribers, sends a notification to the bot owner (if not a
      cross-realm bot) so that the owner can correct the issue."""
      if not sender.is_bot or sender.bot_owner is None:
          return
  
      arg_dict = {
          "bot_identity": f"`{sender.delivery_email}`",
          "stream_id": stream_id,
          "stream_name": f"#**{stream_name}**",
          "new_stream_link": "#streams/new",
      }
      if sender.bot_owner is not None:
          with override_language(sender.bot_owner.default_language):
              if stream is None:
                  if stream_id is not None:
                      content = _(
                          "Your bot {bot_identity} tried to send a message to stream ID "
                          "{stream_id}, but there is no stream with that ID."
                      ).format(**arg_dict)
                  else:
                      assert stream_name is not None
                      content = _(
                          "Your bot {bot_identity} tried to send a message to stream "
                          "{stream_name}, but that stream does not exist. "
                          "Click [here]({new_stream_link}) to create it."
                      ).format(**arg_dict)
              else:
                  if num_subscribers_for_stream_id(stream.id) > 0:
                      return
                  content = _(
                      "Your bot {bot_identity} tried to send a message to "
                      "stream {stream_name}. The stream exists but "
                      "does not have any subscribers."
                  ).format(**arg_dict)
  
          send_rate_limited_pm_notification_to_bot_owner(sender, realm, content)
  
  
  def validate_stream_name_with_pm_notification(
      stream_name: str, realm: Realm, sender: UserProfile
  ) -> Stream:
      stream_name = stream_name.strip()
      check_stream_name(stream_name)
  
      try:
          stream = get_stream(stream_name, realm)
          send_pm_if_empty_stream(stream, realm, sender)
      except Stream.DoesNotExist:
          send_pm_if_empty_stream(None, realm, sender, stream_name=stream_name)
          raise StreamDoesNotExistError(escape(stream_name))
  
      return stream
  
  
  def validate_stream_id_with_pm_notification(
      stream_id: int, realm: Realm, sender: UserProfile
  ) -> Stream:
      try:
          stream = get_stream_by_id_in_realm(stream_id, realm)
          send_pm_if_empty_stream(stream, realm, sender)
      except Stream.DoesNotExist:
          send_pm_if_empty_stream(None, realm, sender, stream_id=stream_id)
          raise StreamWithIDDoesNotExistError(stream_id)
  
      return stream
  
  
  def check_private_message_policy(
      realm: Realm, sender: UserProfile, user_profiles: Sequence[UserProfile]
  ) -> None:
      if realm.private_message_policy == Realm.PRIVATE_MESSAGE_POLICY_DISABLED:
          if sender.is_bot or (len(user_profiles) == 1 and user_profiles[0].is_bot):
              # We allow PMs only between users and bots, to avoid
              # breaking the tutorial as well as automated
              # notifications from system bots to users.
              return
  
          raise JsonableError(_("Private messages are disabled in this organization."))
  
  
  # check_message:
  # Returns message ready for sending with do_send_message on success or the error message (string) on error.
  def check_message(
      sender: UserProfile,
      client: Client,
      addressee: Addressee,
      message_content_raw: str,
      realm: Optional[Realm] = None,
      forged: bool = False,
      forged_timestamp: Optional[float] = None,
      forwarder_user_profile: Optional[UserProfile] = None,
      local_id: Optional[str] = None,
      sender_queue_id: Optional[str] = None,
      widget_content: Optional[str] = None,
      email_gateway: bool = False,
      *,
      skip_stream_access_check: bool = False,
  ) -> SendMessageRequest:
      """See
      https://zulip.readthedocs.io/en/latest/subsystems/sending-messages.html
      for high-level documentation on this subsystem.
      """
      stream = None
  
      message_content = normalize_body(message_content_raw)
  
      if realm is None:
          realm = sender.realm
  
      if addressee.is_stream():
          topic_name = addressee.topic()
          topic_name = truncate_topic(topic_name)
  
          stream_name = addressee.stream_name()
          stream_id = addressee.stream_id()
  
          if stream_name is not None:
              stream = validate_stream_name_with_pm_notification(stream_name, realm, sender)
          elif stream_id is not None:
              stream = validate_stream_id_with_pm_notification(stream_id, realm, sender)
          else:
              stream = addressee.stream()
          assert stream is not None
  
          # To save a database round trip, we construct the Recipient
          # object for the Stream rather than fetching it from the
          # database using the stream.recipient foreign key.
          #
          # This is simpler than ensuring that code paths that fetch a
          # Stream that will be used for sending a message have a
          # `select_related("recipient"), which would also needlessly
          # expand Stream objects in memory (all the fields of Recipient
          # are already known given the Stream object).
          recipient = Recipient(
              id=stream.recipient_id,
              type_id=stream.id,
              type=Recipient.STREAM,
          )
  
          if not skip_stream_access_check:
              access_stream_for_send_message(
                  sender=sender, stream=stream, forwarder_user_profile=forwarder_user_profile
              )
          else:
              # Defensive assertion - the only currently supported use case
              # for this option is for outgoing webhook bots and since this
              # is security-sensitive code, it's beneficial to ensure nothing
              # else can sneak past the access check.
              assert sender.bot_type == sender.OUTGOING_WEBHOOK_BOT
  
      elif addressee.is_private():
          user_profiles = addressee.user_profiles()
          mirror_message = client and client.name in [
              "zephyr_mirror",
              "irc_mirror",
              "jabber_mirror",
              "JabberMirror",
          ]
  
          check_private_message_policy(realm, sender, user_profiles)
  
          # API super-users who set the `forged` flag are allowed to
          # forge messages sent by any user, so we disable the
          # `forwarded_mirror_message` security check in that case.
          forwarded_mirror_message = mirror_message and not forged
          try:
              recipient = recipient_for_user_profiles(
                  user_profiles, forwarded_mirror_message, forwarder_user_profile, sender
              )
          except ValidationError as e:
              assert isinstance(e.messages[0], str)
              raise JsonableError(e.messages[0])
      else:
          # This is defensive code--Addressee already validates
          # the message type.
          raise AssertionError("Invalid message type")
  
      message = Message()
      message.sender = sender
      message.content = message_content
      message.recipient = recipient
      if addressee.is_stream():
          message.set_topic_name(topic_name)
      if forged and forged_timestamp is not None:
          # Forged messages come with a timestamp
          message.date_sent = timestamp_to_datetime(forged_timestamp)
      else:
          message.date_sent = timezone_now()
      message.sending_client = client
  
      # We render messages later in the process.
      assert message.rendered_content is None
  
      if client.name == "zephyr_mirror":
          id = already_sent_mirrored_message_id(message)
          if id is not None:
              raise ZephyrMessageAlreadySentException(id)
  
      widget_content_dict = None
      if widget_content is not None:
          try:
              widget_content_dict = orjson.loads(widget_content)
          except orjson.JSONDecodeError:
              raise JsonableError(_("Widgets: API programmer sent invalid JSON content"))
  
          try:
              check_widget_content(widget_content_dict)
          except ValidationError as error:
              raise JsonableError(
                  _("Widgets: {error_msg}").format(
                      error_msg=error.message,
                  )
              )
  
      message_send_dict = build_message_send_dict(
          message=message,
          stream=stream,
          local_id=local_id,
          sender_queue_id=sender_queue_id,
          realm=realm,
          widget_content_dict=widget_content_dict,
          email_gateway=email_gateway,
      )
  
      if stream is not None and message_send_dict.rendering_result.mentions_wildcard:
          if not wildcard_mention_allowed(sender, stream):
              raise JsonableError(
                  _("You do not have permission to use wildcard mentions in this stream.")
              )
      return message_send_dict
  
  
  def _internal_prep_message(
      realm: Realm,
      sender: UserProfile,
      addressee: Addressee,
      content: str,
      email_gateway: bool = False,
  ) -> Optional[SendMessageRequest]:
      """
      Create a message object and checks it, but doesn't send it or save it to the database.
      The internal function that calls this can therefore batch send a bunch of created
      messages together as one database query.
      Call do_send_messages with a list of the return values of this method.
      """
      # Remove any null bytes from the content
      if len(content) > settings.MAX_MESSAGE_LENGTH:
          content = content[0:3900] + "\n\n[message was too long and has been truncated]"
  
      # If we have a stream name, and the stream doesn't exist, we
      # create it here (though this code path should probably be removed
      # eventually, moving that responsibility to the caller).  If
      # addressee.stream_name() is None (i.e. we're sending to a stream
      # by ID), we skip this, as the stream object must already exist.
      if addressee.is_stream():
          stream_name = addressee.stream_name()
          if stream_name is not None:
              ensure_stream(realm, stream_name, acting_user=sender)
  
      try:
          return check_message(
              sender,
              get_client("Internal"),
              addressee,
              content,
              realm=realm,
              email_gateway=email_gateway,
          )
      except JsonableError as e:
          logging.exception(
              "Error queueing internal message by %s: %s",
              sender.delivery_email,
              e.msg,
              stack_info=True,
          )
  
      return None
  
  
  def internal_prep_stream_message(
      sender: UserProfile,
      stream: Stream,
      topic: str,
      content: str,
      email_gateway: bool = False,
  ) -> Optional[SendMessageRequest]:
      """
      See _internal_prep_message for details of how this works.
      """
      realm = stream.realm
      addressee = Addressee.for_stream(stream, topic)
  
      return _internal_prep_message(
          realm=realm,
          sender=sender,
          addressee=addressee,
          content=content,
          email_gateway=email_gateway,
      )
  
  
  def internal_prep_stream_message_by_name(
      realm: Realm,
      sender: UserProfile,
      stream_name: str,
      topic: str,
      content: str,
  ) -> Optional[SendMessageRequest]:
      """
      See _internal_prep_message for details of how this works.
      """
      addressee = Addressee.for_stream_name(stream_name, topic)
  
      return _internal_prep_message(
          realm=realm,
          sender=sender,
          addressee=addressee,
          content=content,
      )
  
  
  def internal_prep_private_message(
      realm: Realm, sender: UserProfile, recipient_user: UserProfile, content: str
  ) -> Optional[SendMessageRequest]:
      """
      See _internal_prep_message for details of how this works.
      """
      addressee = Addressee.for_user_profile(recipient_user)
  
      return _internal_prep_message(
          realm=realm,
          sender=sender,
          addressee=addressee,
          content=content,
      )
  
  
  def internal_send_private_message(
      sender: UserProfile, recipient_user: UserProfile, content: str
  ) -> Optional[int]:
      realm = recipient_user.realm
      message = internal_prep_private_message(realm, sender, recipient_user, content)
      if message is None:
          return None
      message_ids = do_send_messages([message])
      return message_ids[0]
  
  
  def internal_send_stream_message(
      sender: UserProfile,
      stream: Stream,
      topic: str,
      content: str,
      email_gateway: bool = False,
  ) -> Optional[int]:
  
      message = internal_prep_stream_message(sender, stream, topic, content, email_gateway)
  
      if message is None:
          return None
      message_ids = do_send_messages([message])
      return message_ids[0]
  
  
  def internal_send_stream_message_by_name(
      realm: Realm,
      sender: UserProfile,
      stream_name: str,
      topic: str,
      content: str,
  ) -> Optional[int]:
      message = internal_prep_stream_message_by_name(
          realm,
          sender,
          stream_name,
          topic,
          content,
      )
  
      if message is None:
          return None
      message_ids = do_send_messages([message])
      return message_ids[0]
  
  
  def internal_send_huddle_message(
      realm: Realm, sender: UserProfile, emails: List[str], content: str
  ) -> Optional[int]:
      addressee = Addressee.for_private(emails, realm)
      message = _internal_prep_message(
          realm=realm,
          sender=sender,
          addressee=addressee,
          content=content,
      )
      if message is None:
          return None
      message_ids = do_send_messages([message])
      return message_ids[0]
  
  
  def pick_color(user_profile: UserProfile, used_colors: Set[str]) -> str:
      # These colors are shared with the palette in stream_settings_ui.js.
      available_colors = [s for s in STREAM_ASSIGNMENT_COLORS if s not in used_colors]
  
      if available_colors:
          return available_colors[0]
      else:
          return STREAM_ASSIGNMENT_COLORS[len(used_colors) % len(STREAM_ASSIGNMENT_COLORS)]
  
  
  def validate_user_access_to_subscribers(
      user_profile: Optional[UserProfile], stream: Stream
  ) -> None:
      """Validates whether the user can view the subscribers of a stream.  Raises a JsonableError if:
      * The user and the stream are in different realms
      * The realm is MIT and the stream is not invite only.
      * The stream is invite only, requesting_user is passed, and that user
        does not subscribe to the stream.
      """
      validate_user_access_to_subscribers_helper(
          user_profile,
          {
              "realm_id": stream.realm_id,
              "is_web_public": stream.is_web_public,
              "invite_only": stream.invite_only,
          },
          # We use a lambda here so that we only compute whether the
          # user is subscribed if we have to
          lambda user_profile: subscribed_to_stream(user_profile, stream.id),
      )
  
  
  def validate_user_access_to_subscribers_helper(
      user_profile: Optional[UserProfile],
      stream_dict: Mapping[str, Any],
      check_user_subscribed: Callable[[UserProfile], bool],
  ) -> None:
      """Helper for validate_user_access_to_subscribers that doesn't require
      a full stream object.  This function is a bit hard to read,
      because it is carefully optimized for performance in the two code
      paths we call it from:
  
      * In `bulk_get_subscriber_user_ids`, we already know whether the
      user was subscribed via `sub_dict`, and so we want to avoid a
      database query at all (especially since it calls this in a loop);
      * In `validate_user_access_to_subscribers`, we want to only check
      if the user is subscribed when we absolutely have to, since it
      costs a database query.
  
      The `check_user_subscribed` argument is a function that reports
      whether the user is subscribed to the stream.
  
      Note also that we raise a ValidationError in cases where the
      caller is doing the wrong thing (maybe these should be
      AssertionErrors), and JsonableError for 400 type errors.
      """
      if user_profile is None:
          raise ValidationError("Missing user to validate access for")
  
      if user_profile.realm_id != stream_dict["realm_id"]:
          raise ValidationError("Requesting user not in given realm")
  
      # Even guest users can access subscribers to web-public streams,
      # since they can freely become subscribers to these streams.
      if stream_dict["is_web_public"]:
          return
  
      # With the exception of web public streams, a guest must
      # be subscribed to a stream (even a public one) in order
      # to see subscribers.
      if user_profile.is_guest:
          if check_user_subscribed(user_profile):
              return
          # We could explicitly handle the case where guests aren't
          # subscribed here in an `else` statement or we can fall
          # through to the subsequent logic.  Tim prefers the latter.
          # Adding an `else` would ensure better code coverage.
  
      if not user_profile.can_access_public_streams() and not stream_dict["invite_only"]:
          raise JsonableError(_("Subscriber data is not available for this stream"))
  
      # Organization administrators can view subscribers for all streams.
      if user_profile.is_realm_admin:
          return
  
      if stream_dict["invite_only"] and not check_user_subscribed(user_profile):
          raise JsonableError(_("Unable to retrieve subscribers for private stream"))
  
  
  def bulk_get_subscriber_user_ids(
      stream_dicts: Collection[Mapping[str, Any]],
      user_profile: UserProfile,
      subscribed_stream_ids: Set[int],
  ) -> Dict[int, List[int]]:
      """sub_dict maps stream_id => whether the user is subscribed to that stream."""
      target_stream_dicts = []
      for stream_dict in stream_dicts:
          stream_id = stream_dict["id"]
          is_subscribed = stream_id in subscribed_stream_ids
  
          try:
              validate_user_access_to_subscribers_helper(
                  user_profile,
                  stream_dict,
                  lambda user_profile: is_subscribed,
              )
          except JsonableError:
              continue
          target_stream_dicts.append(stream_dict)
  
      recip_to_stream_id = {stream["recipient_id"]: stream["id"] for stream in target_stream_dicts}
      recipient_ids = sorted(stream["recipient_id"] for stream in target_stream_dicts)
  
      result: Dict[int, List[int]] = {stream["id"]: [] for stream in stream_dicts}
      if not recipient_ids:
          return result
  
      """
      The raw SQL below leads to more than a 2x speedup when tested with
      20k+ total subscribers.  (For large realms with lots of default
      streams, this function deals with LOTS of data, so it is important
      to optimize.)
      """
  
      query = SQL(
          """
          SELECT
              zerver_subscription.recipient_id,
              zerver_subscription.user_profile_id
          FROM
              zerver_subscription
          WHERE
              zerver_subscription.recipient_id in %(recipient_ids)s AND
              zerver_subscription.active AND
              zerver_subscription.is_user_active
          ORDER BY
              zerver_subscription.recipient_id,
              zerver_subscription.user_profile_id
          """
      )
  
      cursor = connection.cursor()
      cursor.execute(query, {"recipient_ids": tuple(recipient_ids)})
      rows = cursor.fetchall()
      cursor.close()
  
      """
      Using groupby/itemgetter here is important for performance, at scale.
      It makes it so that all interpreter overhead is just O(N) in nature.
      """
      for recip_id, recip_rows in itertools.groupby(rows, itemgetter(0)):
          user_profile_ids = [r[1] for r in recip_rows]
          stream_id = recip_to_stream_id[recip_id]
          result[stream_id] = list(user_profile_ids)
  
      return result
  
  
  def get_subscribers_query(stream: Stream, requesting_user: Optional[UserProfile]) -> QuerySet:
      # TODO: Make a generic stub for QuerySet
      """Build a query to get the subscribers list for a stream, raising a JsonableError if:
  
      'realm' is optional in stream.
  
      The caller can refine this query with select_related(), values(), etc. depending
      on whether it wants objects or just certain fields
      """
      validate_user_access_to_subscribers(requesting_user, stream)
  
      return get_active_subscriptions_for_stream_id(stream.id, include_deactivated_users=False)
  
  
  def get_subscriber_ids(stream: Stream, requesting_user: Optional[UserProfile] = None) -> List[str]:
      subscriptions_query = get_subscribers_query(stream, requesting_user)
      return subscriptions_query.values_list("user_profile_id", flat=True)
  
  
  def send_subscription_add_events(
      realm: Realm,
      sub_info_list: List[SubInfo],
      subscriber_dict: Dict[int, Set[int]],
  ) -> None:
      info_by_user: Dict[int, List[SubInfo]] = defaultdict(list)
      for sub_info in sub_info_list:
          info_by_user[sub_info.user.id].append(sub_info)
  
      stream_ids = {sub_info.stream.id for sub_info in sub_info_list}
      recent_traffic = get_streams_traffic(stream_ids=stream_ids)
  
      for user_id, sub_infos in info_by_user.items():
          sub_dicts = []
          for sub_info in sub_infos:
              stream = sub_info.stream
              subscription = sub_info.sub
              sub_dict = stream.to_dict()
              for field_name in Subscription.API_FIELDS:
                  sub_dict[field_name] = getattr(subscription, field_name)
  
              sub_dict["in_home_view"] = not subscription.is_muted
              sub_dict["email_address"] = encode_email_address(stream, show_sender=True)
              sub_dict["stream_weekly_traffic"] = get_average_weekly_stream_traffic(
                  stream.id, stream.date_created, recent_traffic
              )
              if stream.is_in_zephyr_realm and not stream.invite_only:
                  sub_dict["subscribers"] = []
              else:
                  sub_dict["subscribers"] = list(subscriber_dict[stream.id])
              sub_dicts.append(sub_dict)
  
          # Send a notification to the user who subscribed.
          event = dict(type="subscription", op="add", subscriptions=sub_dicts)
          send_event(realm, event, [user_id])
  
  
  SubT = Tuple[List[SubInfo], List[SubInfo]]
  
  
  def bulk_add_subscriptions(
      realm: Realm,
      streams: Collection[Stream],
      users: Iterable[UserProfile],
      color_map: Mapping[str, str] = {},
      from_user_creation: bool = False,
      *,
      acting_user: Optional[UserProfile],
  ) -> SubT:
      users = list(users)
  
      # Sanity check out callers
      for stream in streams:
          assert stream.realm_id == realm.id
  
      for user in users:
          assert user.realm_id == realm.id
  
      recipient_id_to_stream = {stream.recipient_id: stream for stream in streams}
  
      subs_by_user: Dict[int, List[Subscription]] = defaultdict(list)
      all_subs_query = get_stream_subscriptions_for_users(users)
      for sub in all_subs_query:
          subs_by_user[sub.user_profile_id].append(sub)
  
      already_subscribed: List[SubInfo] = []
      subs_to_activate: List[SubInfo] = []
      subs_to_add: List[SubInfo] = []
      for user_profile in users:
          my_subs = subs_by_user[user_profile.id]
          used_colors = {sub.color for sub in my_subs}
  
          # Make a fresh set of all new recipient ids, and then we will
          # remove any for which our user already has a subscription
          # (and we'll re-activate any subscriptions as needed).
          new_recipient_ids = {stream.recipient_id for stream in streams}
  
          for sub in my_subs:
              if sub.recipient_id in new_recipient_ids:
                  new_recipient_ids.remove(sub.recipient_id)
                  stream = recipient_id_to_stream[sub.recipient_id]
                  sub_info = SubInfo(user_profile, sub, stream)
                  if sub.active:
                      already_subscribed.append(sub_info)
                  else:
                      subs_to_activate.append(sub_info)
  
          for recipient_id in new_recipient_ids:
              stream = recipient_id_to_stream[recipient_id]
  
              if stream.name in color_map:
                  color = color_map[stream.name]
              else:
                  color = pick_color(user_profile, used_colors)
              used_colors.add(color)
  
              sub = Subscription(
                  user_profile=user_profile,
                  is_user_active=user_profile.is_active,
                  active=True,
                  color=color,
                  recipient_id=recipient_id,
              )
              sub_info = SubInfo(user_profile, sub, stream)
              subs_to_add.append(sub_info)
  
      bulk_add_subs_to_db_with_logging(
          realm=realm,
          acting_user=acting_user,
          subs_to_add=subs_to_add,
          subs_to_activate=subs_to_activate,
      )
  
      altered_user_dict: Dict[int, Set[int]] = defaultdict(set)
      for sub_info in subs_to_add + subs_to_activate:
          altered_user_dict[sub_info.stream.id].add(sub_info.user.id)
  
      stream_dict = {stream.id: stream for stream in streams}
  
      new_streams = [stream_dict[stream_id] for stream_id in altered_user_dict]
  
      subscriber_peer_info = bulk_get_subscriber_peer_info(
          realm=realm,
          streams=new_streams,
      )
  
      # We now send several types of events to notify browsers.  The
      # first batches of notifications are sent only to the user(s)
      # being subscribed; we can skip these notifications when this is
      # being called from the new user creation flow.
      if not from_user_creation:
          send_stream_creation_events_for_private_streams(
              realm=realm,
              stream_dict=stream_dict,
              altered_user_dict=altered_user_dict,
          )
  
          send_subscription_add_events(
              realm=realm,
              sub_info_list=subs_to_add + subs_to_activate,
              subscriber_dict=subscriber_peer_info.subscribed_ids,
          )
  
      send_peer_subscriber_events(
          op="peer_add",
          realm=realm,
          altered_user_dict=altered_user_dict,
          stream_dict=stream_dict,
          private_peer_dict=subscriber_peer_info.private_peer_dict,
      )
  
      return (
          subs_to_add + subs_to_activate,
          already_subscribed,
      )
  
  
  # This function contains all the database changes as part of
  # subscribing users to streams; we use a transaction to ensure that
  # the RealmAuditLog entries are created atomically with the
  # Subscription object creation (and updates).
  @transaction.atomic
  def bulk_add_subs_to_db_with_logging(
      realm: Realm,
      acting_user: Optional[UserProfile],
      subs_to_add: List[SubInfo],
      subs_to_activate: List[SubInfo],
  ) -> None:
  
      Subscription.objects.bulk_create(info.sub for info in subs_to_add)
      sub_ids = [info.sub.id for info in subs_to_activate]
      Subscription.objects.filter(id__in=sub_ids).update(active=True)
  
      # Log subscription activities in RealmAuditLog
      event_time = timezone_now()
      event_last_message_id = get_last_message_id()
  
      all_subscription_logs: (List[RealmAuditLog]) = []
      for sub_info in subs_to_add:
          all_subscription_logs.append(
              RealmAuditLog(
                  realm=realm,
                  acting_user=acting_user,
                  modified_user=sub_info.user,
                  modified_stream=sub_info.stream,
                  event_last_message_id=event_last_message_id,
                  event_type=RealmAuditLog.SUBSCRIPTION_CREATED,
                  event_time=event_time,
              )
          )
      for sub_info in subs_to_activate:
          all_subscription_logs.append(
              RealmAuditLog(
                  realm=realm,
                  acting_user=acting_user,
                  modified_user=sub_info.user,
                  modified_stream=sub_info.stream,
                  event_last_message_id=event_last_message_id,
                  event_type=RealmAuditLog.SUBSCRIPTION_ACTIVATED,
                  event_time=event_time,
              )
          )
      # Now since we have all log objects generated we can do a bulk insert
      RealmAuditLog.objects.bulk_create(all_subscription_logs)
  
  
  def send_stream_creation_events_for_private_streams(
      realm: Realm,
      stream_dict: Dict[int, Stream],
      altered_user_dict: Dict[int, Set[int]],
  ) -> None:
      for stream_id, stream_users_ids in altered_user_dict.items():
          stream = stream_dict[stream_id]
  
          if not stream.is_public():
              # Users newly added to invite-only streams
              # need a `create` notification.  The former, because
              # they need the stream to exist before
              # they get the "subscribe" notification, and the latter so
              # they can manage the new stream.
              # Realm admins already have all created private streams.
              realm_admin_ids = {user.id for user in realm.get_admin_users_and_bots()}
              notify_user_ids = list(stream_users_ids - realm_admin_ids)
  
              if notify_user_ids:
                  send_stream_creation_event(stream, notify_user_ids)
  
  
  def send_peer_subscriber_events(
      op: str,
      realm: Realm,
      stream_dict: Dict[int, Stream],
      altered_user_dict: Dict[int, Set[int]],
      private_peer_dict: Dict[int, Set[int]],
  ) -> None:
      # Send peer_add/peer_remove events to other users who are tracking the
      # subscribers lists of streams in their browser; everyone for
      # public streams and only existing subscribers for private streams.
  
      assert op in ["peer_add", "peer_remove"]
  
      private_stream_ids = [
          stream_id for stream_id in altered_user_dict if stream_dict[stream_id].invite_only
      ]
  
      for stream_id in private_stream_ids:
          altered_user_ids = altered_user_dict[stream_id]
          peer_user_ids = private_peer_dict[stream_id] - altered_user_ids
  
          if peer_user_ids and altered_user_ids:
              event = dict(
                  type="subscription",
                  op=op,
                  stream_ids=[stream_id],
                  user_ids=sorted(list(altered_user_ids)),
              )
              send_event(realm, event, peer_user_ids)
  
      public_stream_ids = [
          stream_id
          for stream_id in altered_user_dict
          if not stream_dict[stream_id].invite_only and not stream_dict[stream_id].is_in_zephyr_realm
      ]
  
      if public_stream_ids:
          user_streams: Dict[int, Set[int]] = defaultdict(set)
  
          public_peer_ids = set(active_non_guest_user_ids(realm.id))
  
          for stream_id in public_stream_ids:
              altered_user_ids = altered_user_dict[stream_id]
              peer_user_ids = public_peer_ids - altered_user_ids
  
              if peer_user_ids and altered_user_ids:
                  if len(altered_user_ids) == 1:
                      # If we only have one user, we will try to
                      # find other streams they have (un)subscribed to
                      # (where it's just them).  This optimization
                      # typically works when a single user is subscribed
                      # to multiple default public streams during
                      # new-user registration.
                      #
                      # This optimization depends on all public streams
                      # having the same peers for any single user, which
                      # isn't the case for private streams.
                      altered_user_id = list(altered_user_ids)[0]
                      user_streams[altered_user_id].add(stream_id)
                  else:
                      event = dict(
                          type="subscription",
                          op=op,
                          stream_ids=[stream_id],
                          user_ids=sorted(list(altered_user_ids)),
                      )
                      send_event(realm, event, peer_user_ids)
  
          for user_id, stream_ids in user_streams.items():
              peer_user_ids = public_peer_ids - {user_id}
              event = dict(
                  type="subscription",
                  op=op,
                  stream_ids=sorted(list(stream_ids)),
                  user_ids=[user_id],
              )
              send_event(realm, event, peer_user_ids)
  
  
  def send_peer_remove_events(
      realm: Realm,
      streams: List[Stream],
      altered_user_dict: Dict[int, Set[int]],
  ) -> None:
      private_streams = [stream for stream in streams if stream.invite_only]
  
      private_peer_dict = bulk_get_private_peers(
          realm=realm,
          private_streams=private_streams,
      )
      stream_dict = {stream.id: stream for stream in streams}
  
      send_peer_subscriber_events(
          op="peer_remove",
          realm=realm,
          stream_dict=stream_dict,
          altered_user_dict=altered_user_dict,
          private_peer_dict=private_peer_dict,
      )
  
  
  def get_available_notification_sounds() -> List[str]:
      notification_sounds_path = static_path("audio/notification_sounds")
      available_notification_sounds = []
  
      for file_name in os.listdir(notification_sounds_path):
          root, ext = os.path.splitext(file_name)
          if "." in root:  # nocoverage
              # Exclude e.g. zulip.abcd1234.ogg (generated by production hash-naming)
              # to avoid spurious duplicates.
              continue
          if ext == ".ogg":
              available_notification_sounds.append(root)
  
      return sorted(available_notification_sounds)
  
  
  def notify_subscriptions_removed(user_profile: UserProfile, streams: Iterable[Stream]) -> None:
  
      payload = [dict(name=stream.name, stream_id=stream.id) for stream in streams]
      event = dict(type="subscription", op="remove", subscriptions=payload)
      send_event(user_profile.realm, event, [user_profile.id])
  
  
  SubAndRemovedT = Tuple[List[Tuple[UserProfile, Stream]], List[Tuple[UserProfile, Stream]]]
  
  
  def bulk_remove_subscriptions(
      users: Iterable[UserProfile],
      streams: Iterable[Stream],
      *,
      acting_user: Optional[UserProfile],
  ) -> SubAndRemovedT:
  
      users = list(users)
      streams = list(streams)
  
      stream_dict = {stream.id: stream for stream in streams}
  
      existing_subs_by_user = get_bulk_stream_subscriber_info(users, streams)
  
      def get_non_subscribed_subs() -> List[Tuple[UserProfile, Stream]]:
          stream_ids = {stream.id for stream in streams}
  
          not_subscribed: List[Tuple[UserProfile, Stream]] = []
  
          for user_profile in users:
              user_sub_stream_info = existing_subs_by_user[user_profile.id]
  
              subscribed_stream_ids = {sub_info.stream.id for sub_info in user_sub_stream_info}
              not_subscribed_stream_ids = stream_ids - subscribed_stream_ids
  
              for stream_id in not_subscribed_stream_ids:
                  stream = stream_dict[stream_id]
                  not_subscribed.append((user_profile, stream))
  
          return not_subscribed
  
      not_subscribed = get_non_subscribed_subs()
  
      subs_to_deactivate: List[SubInfo] = []
      sub_ids_to_deactivate: List[int] = []
  
      # This loop just flattens out our data into big lists for
      # bulk operations.
      for sub_infos in existing_subs_by_user.values():
          for sub_info in sub_infos:
              subs_to_deactivate.append(sub_info)
              sub_ids_to_deactivate.append(sub_info.sub.id)
  
      our_realm = users[0].realm
  
      # We do all the database changes in a transaction to ensure
      # RealmAuditLog entries are atomically created when making changes.
      with transaction.atomic():
          occupied_streams_before = list(get_occupied_streams(our_realm))
          Subscription.objects.filter(
              id__in=sub_ids_to_deactivate,
          ).update(active=False)
          occupied_streams_after = list(get_occupied_streams(our_realm))
  
          # Log subscription activities in RealmAuditLog
          event_time = timezone_now()
          event_last_message_id = get_last_message_id()
          all_subscription_logs = [
              RealmAuditLog(
                  realm=sub_info.user.realm,
                  acting_user=acting_user,
                  modified_user=sub_info.user,
                  modified_stream=sub_info.stream,
                  event_last_message_id=event_last_message_id,
                  event_type=RealmAuditLog.SUBSCRIPTION_DEACTIVATED,
                  event_time=event_time,
              )
              for sub_info in subs_to_deactivate
          ]
  
          # Now since we have all log objects generated we can do a bulk insert
          RealmAuditLog.objects.bulk_create(all_subscription_logs)
  
      altered_user_dict: Dict[int, Set[int]] = defaultdict(set)
      streams_by_user: Dict[int, List[Stream]] = defaultdict(list)
      for sub_info in subs_to_deactivate:
          stream = sub_info.stream
          streams_by_user[sub_info.user.id].append(stream)
          altered_user_dict[stream.id].add(sub_info.user.id)
  
      for user_profile in users:
          if len(streams_by_user[user_profile.id]) == 0:
              continue
          notify_subscriptions_removed(user_profile, streams_by_user[user_profile.id])
  
          event = {
              "type": "mark_stream_messages_as_read",
              "user_profile_id": user_profile.id,
              "stream_recipient_ids": [stream.recipient_id for stream in streams],
          }
          queue_json_publish("deferred_work", event)
  
      send_peer_remove_events(
          realm=our_realm,
          streams=streams,
          altered_user_dict=altered_user_dict,
      )
  
      new_vacant_streams = set(occupied_streams_before) - set(occupied_streams_after)
      new_vacant_private_streams = [stream for stream in new_vacant_streams if stream.invite_only]
  
      if new_vacant_private_streams:
          # Deactivate any newly-vacant private streams
          for stream in new_vacant_private_streams:
              do_deactivate_stream(stream, acting_user=acting_user)
  
      return (
          [(sub_info.user, sub_info.stream) for sub_info in subs_to_deactivate],
          not_subscribed,
      )
  
  
  def do_change_subscription_property(
      user_profile: UserProfile,
      sub: Subscription,
      stream: Stream,
      property_name: str,
      value: Any,
      *,
      acting_user: Optional[UserProfile],
  ) -> None:
      database_property_name = property_name
      event_property_name = property_name
      database_value = value
      event_value = value
  
      # For this property, is_muted is used in the database, but
      # in_home_view in the API, since we haven't migrated the events
      # API to the new name yet.
      if property_name == "in_home_view":
          database_property_name = "is_muted"
          database_value = not value
      if property_name == "is_muted":
          event_property_name = "in_home_view"
          event_value = not value
  
      old_value = getattr(sub, database_property_name)
      setattr(sub, database_property_name, database_value)
      sub.save(update_fields=[database_property_name])
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          event_type=RealmAuditLog.SUBSCRIPTION_PROPERTY_CHANGED,
          event_time=event_time,
          modified_user=user_profile,
          acting_user=acting_user,
          modified_stream=stream,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: database_value,
                  "property": database_property_name,
              }
          ).decode(),
      )
  
      event = dict(
          type="subscription",
          op="update",
          property=event_property_name,
          value=event_value,
          stream_id=stream.id,
      )
      send_event(user_profile.realm, event, [user_profile.id])
  
  
  def do_change_password(user_profile: UserProfile, password: str, commit: bool = True) -> None:
      user_profile.set_password(password)
      if commit:
          user_profile.save(update_fields=["password"])
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=user_profile,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_PASSWORD_CHANGED,
          event_time=event_time,
      )
  
  
  def do_change_full_name(
      user_profile: UserProfile, full_name: str, acting_user: Optional[UserProfile]
  ) -> None:
      old_name = user_profile.full_name
      user_profile.full_name = full_name
      user_profile.save(update_fields=["full_name"])
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=acting_user,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_FULL_NAME_CHANGED,
          event_time=event_time,
          extra_data=old_name,
      )
      payload = dict(user_id=user_profile.id, full_name=user_profile.full_name)
      send_event(
          user_profile.realm,
          dict(type="realm_user", op="update", person=payload),
          active_user_ids(user_profile.realm_id),
      )
      if user_profile.is_bot:
          send_event(
              user_profile.realm,
              dict(type="realm_bot", op="update", bot=payload),
              bot_owner_user_ids(user_profile),
          )
  
  
  def check_change_full_name(
      user_profile: UserProfile, full_name_raw: str, acting_user: UserProfile
  ) -> str:
      """Verifies that the user's proposed full name is valid.  The caller
      is responsible for checking check permissions.  Returns the new
      full name, which may differ from what was passed in (because this
      function strips whitespace)."""
      new_full_name = check_full_name(full_name_raw)
      do_change_full_name(user_profile, new_full_name, acting_user)
      return new_full_name
  
  
  def check_change_bot_full_name(
      user_profile: UserProfile, full_name_raw: str, acting_user: UserProfile
  ) -> None:
      new_full_name = check_full_name(full_name_raw)
  
      if new_full_name == user_profile.full_name:
          # Our web app will try to patch full_name even if the user didn't
          # modify the name in the form.  We just silently ignore those
          # situations.
          return
  
      check_bot_name_available(
          realm_id=user_profile.realm_id,
          full_name=new_full_name,
      )
      do_change_full_name(user_profile, new_full_name, acting_user)
  
  
  def do_change_bot_owner(
      user_profile: UserProfile, bot_owner: UserProfile, acting_user: UserProfile
  ) -> None:
      previous_owner = user_profile.bot_owner
      user_profile.bot_owner = bot_owner
      user_profile.save()  # Can't use update_fields because of how the foreign key works.
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=acting_user,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_BOT_OWNER_CHANGED,
          event_time=event_time,
      )
  
      update_users = bot_owner_user_ids(user_profile)
  
      # For admins, update event is sent instead of delete/add
      # event. bot_data of admin contains all the
      # bots and none of them should be removed/(added again).
  
      # Delete the bot from previous owner's bot data.
      if previous_owner and not previous_owner.is_realm_admin:
          send_event(
              user_profile.realm,
              dict(
                  type="realm_bot",
                  op="delete",
                  bot=dict(
                      user_id=user_profile.id,
                  ),
              ),
              {previous_owner.id},
          )
          # Do not send update event for previous bot owner.
          update_users = update_users - {previous_owner.id}
  
      # Notify the new owner that the bot has been added.
      if not bot_owner.is_realm_admin:
          add_event = created_bot_event(user_profile)
          send_event(user_profile.realm, add_event, {bot_owner.id})
          # Do not send update event for bot_owner.
          update_users = update_users - {bot_owner.id}
  
      send_event(
          user_profile.realm,
          dict(
              type="realm_bot",
              op="update",
              bot=dict(
                  user_id=user_profile.id,
                  owner_id=user_profile.bot_owner.id,
              ),
          ),
          update_users,
      )
  
      # Since `bot_owner_id` is included in the user profile dict we need
      # to update the users dict with the new bot owner id
      event: Dict[str, Any] = dict(
          type="realm_user",
          op="update",
          person=dict(
              user_id=user_profile.id,
              bot_owner_id=user_profile.bot_owner.id,
          ),
      )
      send_event(user_profile.realm, event, active_user_ids(user_profile.realm_id))
  
  
  def do_change_tos_version(user_profile: UserProfile, tos_version: str) -> None:
      user_profile.tos_version = tos_version
      user_profile.save(update_fields=["tos_version"])
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=user_profile,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_TOS_VERSION_CHANGED,
          event_time=event_time,
      )
  
  
  def do_regenerate_api_key(user_profile: UserProfile, acting_user: UserProfile) -> str:
      old_api_key = user_profile.api_key
      new_api_key = generate_api_key()
      user_profile.api_key = new_api_key
      user_profile.save(update_fields=["api_key"])
  
      # We need to explicitly delete the old API key from our caches,
      # because the on-save handler for flushing the UserProfile object
      # in zerver/lib/cache.py only has access to the new API key.
      cache_delete(user_profile_by_api_key_cache_key(old_api_key))
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=acting_user,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_API_KEY_CHANGED,
          event_time=event_time,
      )
  
      if user_profile.is_bot:
          send_event(
              user_profile.realm,
              dict(
                  type="realm_bot",
                  op="update",
                  bot=dict(
                      user_id=user_profile.id,
                      api_key=new_api_key,
                  ),
              ),
              bot_owner_user_ids(user_profile),
          )
  
      event = {"type": "clear_push_device_tokens", "user_profile_id": user_profile.id}
      queue_json_publish("deferred_work", event)
  
      return new_api_key
  
  
  def notify_avatar_url_change(user_profile: UserProfile) -> None:
      if user_profile.is_bot:
          send_event(
              user_profile.realm,
              dict(
                  type="realm_bot",
                  op="update",
                  bot=dict(
                      user_id=user_profile.id,
                      avatar_url=avatar_url(user_profile),
                  ),
              ),
              bot_owner_user_ids(user_profile),
          )
  
      payload = dict(
          avatar_source=user_profile.avatar_source,
          avatar_url=avatar_url(user_profile),
          avatar_url_medium=avatar_url(user_profile, medium=True),
          avatar_version=user_profile.avatar_version,
          # Even clients using client_gravatar don't need the email,
          # since we're sending the URL anyway.
          user_id=user_profile.id,
      )
  
      send_event(
          user_profile.realm,
          dict(type="realm_user", op="update", person=payload),
          active_user_ids(user_profile.realm_id),
      )
  
  
  def do_change_avatar_fields(
      user_profile: UserProfile,
      avatar_source: str,
      skip_notify: bool = False,
      *,
      acting_user: Optional[UserProfile],
  ) -> None:
      user_profile.avatar_source = avatar_source
      user_profile.avatar_version += 1
      user_profile.save(update_fields=["avatar_source", "avatar_version"])
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_AVATAR_SOURCE_CHANGED,
          extra_data={"avatar_source": avatar_source},
          event_time=event_time,
          acting_user=acting_user,
      )
  
      if not skip_notify:
          notify_avatar_url_change(user_profile)
  
  
  def do_delete_avatar_image(user: UserProfile, *, acting_user: Optional[UserProfile]) -> None:
      do_change_avatar_fields(user, UserProfile.AVATAR_FROM_GRAVATAR, acting_user=acting_user)
      delete_avatar_image(user)
  
  
  def do_change_icon_source(
      realm: Realm, icon_source: str, *, acting_user: Optional[UserProfile]
  ) -> None:
      realm.icon_source = icon_source
      realm.icon_version += 1
      realm.save(update_fields=["icon_source", "icon_version"])
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=realm,
          event_type=RealmAuditLog.REALM_ICON_SOURCE_CHANGED,
          extra_data={"icon_source": icon_source, "icon_version": realm.icon_version},
          event_time=event_time,
          acting_user=acting_user,
      )
  
      send_event(
          realm,
          dict(
              type="realm",
              op="update_dict",
              property="icon",
              data=dict(icon_source=realm.icon_source, icon_url=realm_icon_url(realm)),
          ),
          active_user_ids(realm.id),
      )
  
  
  def do_change_logo_source(
      realm: Realm, logo_source: str, night: bool, *, acting_user: Optional[UserProfile]
  ) -> None:
      if not night:
          realm.logo_source = logo_source
          realm.logo_version += 1
          realm.save(update_fields=["logo_source", "logo_version"])
  
      else:
          realm.night_logo_source = logo_source
          realm.night_logo_version += 1
          realm.save(update_fields=["night_logo_source", "night_logo_version"])
  
      RealmAuditLog.objects.create(
          event_type=RealmAuditLog.REALM_LOGO_CHANGED,
          realm=realm,
          event_time=timezone_now(),
          acting_user=acting_user,
      )
  
      event = dict(
          type="realm",
          op="update_dict",
          property="night_logo" if night else "logo",
          data=get_realm_logo_data(realm, night),
      )
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_change_plan_type(
      realm: Realm, plan_type: int, *, acting_user: Optional[UserProfile]
  ) -> None:
      old_value = realm.plan_type
      realm.plan_type = plan_type
      realm.save(update_fields=["plan_type"])
      RealmAuditLog.objects.create(
          event_type=RealmAuditLog.REALM_PLAN_TYPE_CHANGED,
          realm=realm,
          event_time=timezone_now(),
          acting_user=acting_user,
          extra_data={"old_value": old_value, "new_value": plan_type},
      )
  
      if plan_type == Realm.STANDARD:
          realm.max_invites = Realm.INVITES_STANDARD_REALM_DAILY_MAX
          realm.message_visibility_limit = None
          realm.upload_quota_gb = Realm.UPLOAD_QUOTA_STANDARD
      elif plan_type == Realm.SELF_HOSTED:
          realm.max_invites = None  # type: ignore[assignment] # Apparent mypy bug with Optional[int] setter.
          realm.message_visibility_limit = None
          realm.upload_quota_gb = None
      elif plan_type == Realm.STANDARD_FREE:
          realm.max_invites = Realm.INVITES_STANDARD_REALM_DAILY_MAX
          realm.message_visibility_limit = None
          realm.upload_quota_gb = Realm.UPLOAD_QUOTA_STANDARD
      elif plan_type == Realm.LIMITED:
          realm.max_invites = settings.INVITES_DEFAULT_REALM_DAILY_MAX
          realm.message_visibility_limit = Realm.MESSAGE_VISIBILITY_LIMITED
          realm.upload_quota_gb = Realm.UPLOAD_QUOTA_LIMITED
      else:
          raise AssertionError("Invalid plan type")
  
      update_first_visible_message_id(realm)
  
      realm.save(update_fields=["_max_invites", "message_visibility_limit", "upload_quota_gb"])
  
      event = {
          "type": "realm",
          "op": "update",
          "property": "plan_type",
          "value": plan_type,
          "extra_data": {"upload_quota": realm.upload_quota_bytes()},
      }
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_change_default_sending_stream(
      user_profile: UserProfile, stream: Optional[Stream], *, acting_user: Optional[UserProfile]
  ) -> None:
      old_value = user_profile.default_sending_stream_id
      user_profile.default_sending_stream = stream
      user_profile.save(update_fields=["default_sending_stream"])
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          event_type=RealmAuditLog.USER_DEFAULT_SENDING_STREAM_CHANGED,
          event_time=event_time,
          modified_user=user_profile,
          acting_user=acting_user,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: None if stream is None else stream.id,
              }
          ).decode(),
      )
  
      if user_profile.is_bot:
          if stream:
              stream_name: Optional[str] = stream.name
          else:
              stream_name = None
          send_event(
              user_profile.realm,
              dict(
                  type="realm_bot",
                  op="update",
                  bot=dict(
                      user_id=user_profile.id,
                      default_sending_stream=stream_name,
                  ),
              ),
              bot_owner_user_ids(user_profile),
          )
  
  
  def do_change_default_events_register_stream(
      user_profile: UserProfile, stream: Optional[Stream], *, acting_user: Optional[UserProfile]
  ) -> None:
      old_value = user_profile.default_events_register_stream_id
      user_profile.default_events_register_stream = stream
      user_profile.save(update_fields=["default_events_register_stream"])
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          event_type=RealmAuditLog.USER_DEFAULT_REGISTER_STREAM_CHANGED,
          event_time=event_time,
          modified_user=user_profile,
          acting_user=acting_user,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: None if stream is None else stream.id,
              }
          ).decode(),
      )
  
      if user_profile.is_bot:
          if stream:
              stream_name: Optional[str] = stream.name
          else:
              stream_name = None
          send_event(
              user_profile.realm,
              dict(
                  type="realm_bot",
                  op="update",
                  bot=dict(
                      user_id=user_profile.id,
                      default_events_register_stream=stream_name,
                  ),
              ),
              bot_owner_user_ids(user_profile),
          )
  
  
  def do_change_default_all_public_streams(
      user_profile: UserProfile, value: bool, *, acting_user: Optional[UserProfile]
  ) -> None:
      old_value = user_profile.default_all_public_streams
      user_profile.default_all_public_streams = value
      user_profile.save(update_fields=["default_all_public_streams"])
  
      event_time = timezone_now()
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          event_type=RealmAuditLog.USER_DEFAULT_ALL_PUBLIC_STREAMS_CHANGED,
          event_time=event_time,
          modified_user=user_profile,
          acting_user=acting_user,
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: value,
              }
          ).decode(),
      )
  
      if user_profile.is_bot:
          send_event(
              user_profile.realm,
              dict(
                  type="realm_bot",
                  op="update",
                  bot=dict(
                      user_id=user_profile.id,
                      default_all_public_streams=user_profile.default_all_public_streams,
                  ),
              ),
              bot_owner_user_ids(user_profile),
          )
  
  
  def do_change_user_role(
      user_profile: UserProfile, value: int, *, acting_user: Optional[UserProfile]
  ) -> None:
      old_value = user_profile.role
      user_profile.role = value
      user_profile.save(update_fields=["role"])
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          modified_user=user_profile,
          acting_user=acting_user,
          event_type=RealmAuditLog.USER_ROLE_CHANGED,
          event_time=timezone_now(),
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_value,
                  RealmAuditLog.NEW_VALUE: value,
                  RealmAuditLog.ROLE_COUNT: realm_user_count_by_role(user_profile.realm),
              }
          ).decode(),
      )
      event = dict(
          type="realm_user", op="update", person=dict(user_id=user_profile.id, role=user_profile.role)
      )
      send_event(user_profile.realm, event, active_user_ids(user_profile.realm_id))
  
  
  def do_make_user_billing_admin(user_profile: UserProfile) -> None:
      user_profile.is_billing_admin = True
      user_profile.save(update_fields=["is_billing_admin"])
      event = dict(
          type="realm_user", op="update", person=dict(user_id=user_profile.id, is_billing_admin=True)
      )
      send_event(user_profile.realm, event, active_user_ids(user_profile.realm_id))
  
  
  def do_change_can_forge_sender(user_profile: UserProfile, value: bool) -> None:
      user_profile.can_forge_sender = value
      user_profile.save(update_fields=["can_forge_sender"])
  
  
  def do_change_can_create_users(user_profile: UserProfile, value: bool) -> None:
      user_profile.can_create_users = value
      user_profile.save(update_fields=["can_create_users"])
  
  
  def do_change_stream_invite_only(
      stream: Stream, invite_only: bool, history_public_to_subscribers: Optional[bool] = None
  ) -> None:
      history_public_to_subscribers = get_default_value_for_history_public_to_subscribers(
          stream.realm,
          invite_only,
          history_public_to_subscribers,
      )
      stream.invite_only = invite_only
      stream.history_public_to_subscribers = history_public_to_subscribers
      stream.is_web_public = False
      stream.save(update_fields=["invite_only", "history_public_to_subscribers", "is_web_public"])
      event = dict(
          op="update",
          type="stream",
          property="invite_only",
          value=invite_only,
          history_public_to_subscribers=history_public_to_subscribers,
          is_web_public=False,
          stream_id=stream.id,
          name=stream.name,
      )
      send_event(stream.realm, event, can_access_stream_user_ids(stream))
  
  
  def do_make_stream_web_public(stream: Stream) -> None:
      stream.is_web_public = True
      stream.invite_only = False
      stream.history_public_to_subscribers = True
      stream.save(update_fields=["invite_only", "history_public_to_subscribers", "is_web_public"])
  
  
  def do_change_stream_post_policy(stream: Stream, stream_post_policy: int) -> None:
      stream.stream_post_policy = stream_post_policy
      stream.save(update_fields=["stream_post_policy"])
      event = dict(
          op="update",
          type="stream",
          property="stream_post_policy",
          value=stream_post_policy,
          stream_id=stream.id,
          name=stream.name,
      )
      send_event(stream.realm, event, can_access_stream_user_ids(stream))
  
      # Backwards-compatibility code: We removed the
      # is_announcement_only property in early 2020, but we send a
      # duplicate event for legacy mobile clients that might want the
      # data.
      event = dict(
          op="update",
          type="stream",
          property="is_announcement_only",
          value=stream.stream_post_policy == Stream.STREAM_POST_POLICY_ADMINS,
          stream_id=stream.id,
          name=stream.name,
      )
      send_event(stream.realm, event, can_access_stream_user_ids(stream))
  
  
  def do_rename_stream(stream: Stream, new_name: str, user_profile: UserProfile) -> Dict[str, str]:
      old_name = stream.name
      stream.name = new_name
      stream.save(update_fields=["name"])
  
      RealmAuditLog.objects.create(
          realm=stream.realm,
          acting_user=user_profile,
          modified_stream=stream,
          event_type=RealmAuditLog.STREAM_NAME_CHANGED,
          event_time=timezone_now(),
          extra_data=orjson.dumps(
              {
                  RealmAuditLog.OLD_VALUE: old_name,
                  RealmAuditLog.NEW_VALUE: new_name,
              }
          ).decode(),
      )
  
      recipient_id = stream.recipient_id
      messages = Message.objects.filter(recipient_id=recipient_id).only("id")
  
      # Update the display recipient and stream, which are easy single
      # items to set.
      old_cache_key = get_stream_cache_key(old_name, stream.realm_id)
      new_cache_key = get_stream_cache_key(stream.name, stream.realm_id)
      if old_cache_key != new_cache_key:
          cache_delete(old_cache_key)
          cache_set(new_cache_key, stream)
      cache_set(display_recipient_cache_key(recipient_id), stream.name)
  
      # Delete cache entries for everything else, which is cheaper and
      # clearer than trying to set them. display_recipient is the out of
      # date field in all cases.
      cache_delete_many(to_dict_cache_key_id(message.id) for message in messages)
      new_email = encode_email_address(stream, show_sender=True)
  
      # We will tell our users to essentially
      # update stream.name = new_name where name = old_name
      # and update stream.email = new_email where name = old_name.
      # We could optimize this by trying to send one message, but the
      # client code really wants one property update at a time, and
      # updating stream names is a pretty infrequent operation.
      # More importantly, we want to key these updates by id, not name,
      # since id is the immutable primary key, and obviously name is not.
      data_updates = [
          ["email_address", new_email],
          ["name", new_name],
      ]
      for property, value in data_updates:
          event = dict(
              op="update",
              type="stream",
              property=property,
              value=value,
              stream_id=stream.id,
              name=old_name,
          )
          send_event(stream.realm, event, can_access_stream_user_ids(stream))
      sender = get_system_bot(settings.NOTIFICATION_BOT, stream.realm_id)
      with override_language(stream.realm.default_language):
          internal_send_stream_message(
              sender,
              stream,
              Realm.STREAM_EVENTS_NOTIFICATION_TOPIC,
              _("{user_name} renamed stream {old_stream_name} to {new_stream_name}.").format(
                  user_name=f"@_**{user_profile.full_name}|{user_profile.id}**",
                  old_stream_name=f"**{old_name}**",
                  new_stream_name=f"**{new_name}**",
              ),
          )
      # Even though the token doesn't change, the web client needs to update the
      # email forwarding address to display the correctly-escaped new name.
      return {"email_address": new_email}
  
  
  def do_change_stream_description(stream: Stream, new_description: str) -> None:
      stream.description = new_description
      stream.rendered_description = render_stream_description(new_description)
      stream.save(update_fields=["description", "rendered_description"])
  
      event = dict(
          type="stream",
          op="update",
          property="description",
          name=stream.name,
          stream_id=stream.id,
          value=new_description,
          rendered_description=stream.rendered_description,
      )
      send_event(stream.realm, event, can_access_stream_user_ids(stream))
  
  
  def do_change_stream_message_retention_days(
      stream: Stream, message_retention_days: Optional[int] = None
  ) -> None:
      stream.message_retention_days = message_retention_days
      stream.save(update_fields=["message_retention_days"])
  
      event = dict(
          op="update",
          type="stream",
          property="message_retention_days",
          value=message_retention_days,
          stream_id=stream.id,
          name=stream.name,
      )
      send_event(stream.realm, event, can_access_stream_user_ids(stream))
  
  
  def do_create_realm(
      string_id: str,
      name: str,
      *,
      emails_restricted_to_domains: Optional[bool] = None,
      email_address_visibility: Optional[int] = None,
      description: Optional[str] = None,
      invite_required: Optional[bool] = None,
      plan_type: Optional[int] = None,
      org_type: Optional[int] = None,
      date_created: Optional[datetime.datetime] = None,
      is_demo_organization: Optional[bool] = False,
  ) -> Realm:
      if Realm.objects.filter(string_id=string_id).exists():
          raise AssertionError(f"Realm {string_id} already exists!")
      if not server_initialized():
          logging.info("Server not yet initialized. Creating the internal realm first.")
          create_internal_realm()
  
      kwargs: Dict[str, Any] = {}
      if emails_restricted_to_domains is not None:
          kwargs["emails_restricted_to_domains"] = emails_restricted_to_domains
      if email_address_visibility is not None:
          kwargs["email_address_visibility"] = email_address_visibility
      if description is not None:
          kwargs["description"] = description
      if invite_required is not None:
          kwargs["invite_required"] = invite_required
      if plan_type is not None:
          kwargs["plan_type"] = plan_type
      if org_type is not None:
          kwargs["org_type"] = org_type
  
      if date_created is not None:
          # The date_created parameter is intended only for use by test
          # suites that want to backdate the date of a realm's creation.
          assert not settings.PRODUCTION
          kwargs["date_created"] = date_created
  
      with transaction.atomic():
          realm = Realm(string_id=string_id, name=name, **kwargs)
          if is_demo_organization:
              realm.demo_organization_scheduled_deletion_date = (
                  realm.date_created + datetime.timedelta(days=settings.DEMO_ORG_DEADLINE_DAYS)
              )
          realm.save()
  
          RealmAuditLog.objects.create(
              realm=realm, event_type=RealmAuditLog.REALM_CREATED, event_time=realm.date_created
          )
  
          RealmUserDefault.objects.create(realm=realm)
  
      # Create stream once Realm object has been saved
      notifications_stream = ensure_stream(
          realm,
          Realm.DEFAULT_NOTIFICATION_STREAM_NAME,
          stream_description="Everyone is added to this stream by default. Welcome! :octopus:",
          acting_user=None,
      )
      realm.notifications_stream = notifications_stream
  
      # With the current initial streams situation, the only public
      # stream is the notifications_stream.
      DefaultStream.objects.create(stream=notifications_stream, realm=realm)
  
      signup_notifications_stream = ensure_stream(
          realm,
          Realm.INITIAL_PRIVATE_STREAM_NAME,
          invite_only=True,
          stream_description="A private stream for core team members.",
          acting_user=None,
      )
      realm.signup_notifications_stream = signup_notifications_stream
  
      realm.save(update_fields=["notifications_stream", "signup_notifications_stream"])
  
      if plan_type is None and settings.BILLING_ENABLED:
          do_change_plan_type(realm, Realm.LIMITED, acting_user=None)
  
      admin_realm = get_realm(settings.SYSTEM_BOT_REALM)
      sender = get_system_bot(settings.NOTIFICATION_BOT, admin_realm.id)
      # Send a notification to the admin realm
      signup_message = _("Signups enabled")
  
      try:
          signups_stream = get_signups_stream(admin_realm)
          topic = realm.display_subdomain
  
          internal_send_stream_message(
              sender,
              signups_stream,
              topic,
              signup_message,
          )
      except Stream.DoesNotExist:  # nocoverage
          # If the signups stream hasn't been created in the admin
          # realm, don't auto-create it to send to it; just do nothing.
          pass
      return realm
  
  
  def do_change_user_setting(
      user_profile: UserProfile,
      setting_name: str,
      setting_value: Union[bool, str, int],
      *,
      acting_user: Optional[UserProfile],
  ) -> None:
      old_value = getattr(user_profile, setting_name)
      event_time = timezone_now()
  
      if setting_name == "timezone":
          assert isinstance(setting_value, str)
      else:
          property_type = UserProfile.property_types[setting_name]
          assert isinstance(setting_value, property_type)
      setattr(user_profile, setting_name, setting_value)
  
      # TODO: Move these database actions into a transaction.atomic block.
      user_profile.save(update_fields=[setting_name])
  
      if setting_name in UserProfile.notification_setting_types:
          # Prior to all personal settings being managed by property_types,
          # these were only created for notification settings.
          #
          # TODO: Start creating these for all settings, and do a
          # backfilled=True migration.
          RealmAuditLog.objects.create(
              realm=user_profile.realm,
              event_type=RealmAuditLog.USER_SETTING_CHANGED,
              event_time=event_time,
              acting_user=acting_user,
              modified_user=user_profile,
              extra_data=orjson.dumps(
                  {
                      RealmAuditLog.OLD_VALUE: old_value,
                      RealmAuditLog.NEW_VALUE: setting_value,
                      "property": setting_name,
                  }
              ).decode(),
          )
      # Disabling digest emails should clear a user's email queue
      if setting_name == "enable_digest_emails" and not setting_value:
          clear_scheduled_emails(user_profile.id, ScheduledEmail.DIGEST)
  
      event = {
          "type": "user_settings",
          "op": "update",
          "property": setting_name,
          "value": setting_value,
      }
      if setting_name == "default_language":
          assert isinstance(setting_value, str)
          event["language_name"] = get_language_name(setting_value)
  
      send_event(user_profile.realm, event, [user_profile.id])
  
      if setting_name in UserProfile.notification_settings_legacy:
          # This legacy event format is for backwards-compatiblity with
          # clients that don't support the new user_settings event type.
          # We only send this for settings added before Feature level 89.
          legacy_event = {
              "type": "update_global_notifications",
              "user": user_profile.email,
              "notification_name": setting_name,
              "setting": setting_value,
          }
          send_event(user_profile.realm, legacy_event, [user_profile.id])
  
      if setting_name in UserProfile.display_settings_legacy or setting_name == "timezone":
          # This legacy event format is for backwards-compatiblity with
          # clients that don't support the new user_settings event type.
          # We only send this for settings added before Feature level 89.
          legacy_event = {
              "type": "update_display_settings",
              "user": user_profile.email,
              "setting_name": setting_name,
              "setting": setting_value,
          }
          if setting_name == "default_language":
              assert isinstance(setting_value, str)
              legacy_event["language_name"] = get_language_name(setting_value)
  
          send_event(user_profile.realm, legacy_event, [user_profile.id])
  
      # Updates to the timezone display setting are sent to all users
      if setting_name == "timezone":
          payload = dict(
              email=user_profile.email,
              user_id=user_profile.id,
              timezone=canonicalize_timezone(user_profile.timezone),
          )
          send_event(
              user_profile.realm,
              dict(type="realm_user", op="update", person=payload),
              active_user_ids(user_profile.realm_id),
          )
  
      if setting_name == "enable_drafts_synchronization" and setting_value is False:
          # Delete all of the drafts from the backend but don't send delete events
          # for them since all that's happened is that we stopped syncing changes,
          # not deleted every previously synced draft - to do that use the DELETE
          # endpoint.
          Draft.objects.filter(user_profile=user_profile).delete()
  
  
  def lookup_default_stream_groups(
      default_stream_group_names: List[str], realm: Realm
  ) -> List[DefaultStreamGroup]:
      default_stream_groups = []
      for group_name in default_stream_group_names:
          try:
              default_stream_group = DefaultStreamGroup.objects.get(name=group_name, realm=realm)
          except DefaultStreamGroup.DoesNotExist:
              raise JsonableError(_("Invalid default stream group {}").format(group_name))
          default_stream_groups.append(default_stream_group)
      return default_stream_groups
  
  
  def notify_default_streams(realm: Realm) -> None:
      event = dict(
          type="default_streams",
          default_streams=streams_to_dicts_sorted(get_default_streams_for_realm(realm.id)),
      )
      send_event(realm, event, active_non_guest_user_ids(realm.id))
  
  
  def notify_default_stream_groups(realm: Realm) -> None:
      event = dict(
          type="default_stream_groups",
          default_stream_groups=default_stream_groups_to_dicts_sorted(
              get_default_stream_groups(realm)
          ),
      )
      send_event(realm, event, active_non_guest_user_ids(realm.id))
  
  
  def do_add_default_stream(stream: Stream) -> None:
      realm_id = stream.realm_id
      stream_id = stream.id
      if not DefaultStream.objects.filter(realm_id=realm_id, stream_id=stream_id).exists():
          DefaultStream.objects.create(realm_id=realm_id, stream_id=stream_id)
          notify_default_streams(stream.realm)
  
  
  def do_remove_default_stream(stream: Stream) -> None:
      realm_id = stream.realm_id
      stream_id = stream.id
      DefaultStream.objects.filter(realm_id=realm_id, stream_id=stream_id).delete()
      notify_default_streams(stream.realm)
  
  
  def do_create_default_stream_group(
      realm: Realm, group_name: str, description: str, streams: List[Stream]
  ) -> None:
      default_streams = get_default_streams_for_realm(realm.id)
      for stream in streams:
          if stream in default_streams:
              raise JsonableError(
                  _(
                      "'{stream_name}' is a default stream and cannot be added to '{group_name}'",
                  ).format(stream_name=stream.name, group_name=group_name)
              )
  
      check_default_stream_group_name(group_name)
      (group, created) = DefaultStreamGroup.objects.get_or_create(
          name=group_name, realm=realm, description=description
      )
      if not created:
          raise JsonableError(
              _(
                  "Default stream group '{group_name}' already exists",
              ).format(group_name=group_name)
          )
  
      group.streams.set(streams)
      notify_default_stream_groups(realm)
  
  
  def do_add_streams_to_default_stream_group(
      realm: Realm, group: DefaultStreamGroup, streams: List[Stream]
  ) -> None:
      default_streams = get_default_streams_for_realm(realm.id)
      for stream in streams:
          if stream in default_streams:
              raise JsonableError(
                  _(
                      "'{stream_name}' is a default stream and cannot be added to '{group_name}'",
                  ).format(stream_name=stream.name, group_name=group.name)
              )
          if stream in group.streams.all():
              raise JsonableError(
                  _(
                      "Stream '{stream_name}' is already present in default stream group '{group_name}'",
                  ).format(stream_name=stream.name, group_name=group.name)
              )
          group.streams.add(stream)
  
      group.save()
      notify_default_stream_groups(realm)
  
  
  def do_remove_streams_from_default_stream_group(
      realm: Realm, group: DefaultStreamGroup, streams: List[Stream]
  ) -> None:
      for stream in streams:
          if stream not in group.streams.all():
              raise JsonableError(
                  _(
                      "Stream '{stream_name}' is not present in default stream group '{group_name}'",
                  ).format(stream_name=stream.name, group_name=group.name)
              )
          group.streams.remove(stream)
  
      group.save()
      notify_default_stream_groups(realm)
  
  
  def do_change_default_stream_group_name(
      realm: Realm, group: DefaultStreamGroup, new_group_name: str
  ) -> None:
      if group.name == new_group_name:
          raise JsonableError(
              _("This default stream group is already named '{}'").format(new_group_name)
          )
  
      if DefaultStreamGroup.objects.filter(name=new_group_name, realm=realm).exists():
          raise JsonableError(_("Default stream group '{}' already exists").format(new_group_name))
  
      group.name = new_group_name
      group.save()
      notify_default_stream_groups(realm)
  
  
  def do_change_default_stream_group_description(
      realm: Realm, group: DefaultStreamGroup, new_description: str
  ) -> None:
      group.description = new_description
      group.save()
      notify_default_stream_groups(realm)
  
  
  def do_remove_default_stream_group(realm: Realm, group: DefaultStreamGroup) -> None:
      group.delete()
      notify_default_stream_groups(realm)
  
  
  def get_default_streams_for_realm(realm_id: int) -> List[Stream]:
      return [
          default.stream
          for default in DefaultStream.objects.select_related().filter(realm_id=realm_id)
      ]
  
  
  def get_default_subs(user_profile: UserProfile) -> List[Stream]:
      # Right now default streams are realm-wide.  This wrapper gives us flexibility
      # to some day further customize how we set up default streams for new users.
      return get_default_streams_for_realm(user_profile.realm_id)
  
  
  # returns default streams in json serializeable format
  def streams_to_dicts_sorted(streams: List[Stream]) -> List[Dict[str, Any]]:
      return sorted((stream.to_dict() for stream in streams), key=lambda elt: elt["name"])
  
  
  def default_stream_groups_to_dicts_sorted(groups: List[DefaultStreamGroup]) -> List[Dict[str, Any]]:
      return sorted((group.to_dict() for group in groups), key=lambda elt: elt["name"])
  
  
  def do_update_user_activity_interval(
      user_profile: UserProfile, log_time: datetime.datetime
  ) -> None:
      effective_end = log_time + UserActivityInterval.MIN_INTERVAL_LENGTH
      # This code isn't perfect, because with various races we might end
      # up creating two overlapping intervals, but that shouldn't happen
      # often, and can be corrected for in post-processing
      try:
          last = UserActivityInterval.objects.filter(user_profile=user_profile).order_by("-end")[0]
          # Two intervals overlap iff each interval ends after the other
          # begins.  In this case, we just extend the old interval to
          # include the new interval.
          if log_time <= last.end and effective_end >= last.start:
              last.end = max(last.end, effective_end)
              last.start = min(last.start, log_time)
              last.save(update_fields=["start", "end"])
              return
      except IndexError:
          pass
  
      # Otherwise, the intervals don't overlap, so we should make a new one
      UserActivityInterval.objects.create(
          user_profile=user_profile, start=log_time, end=effective_end
      )
  
  
  @statsd_increment("user_activity")
  def do_update_user_activity(
      user_profile_id: int, client_id: int, query: str, count: int, log_time: datetime.datetime
  ) -> None:
      (activity, created) = UserActivity.objects.get_or_create(
          user_profile_id=user_profile_id,
          client_id=client_id,
          query=query,
          defaults={"last_visit": log_time, "count": count},
      )
  
      if not created:
          activity.count += count
          activity.last_visit = log_time
          activity.save(update_fields=["last_visit", "count"])
  
  
  def send_presence_changed(user_profile: UserProfile, presence: UserPresence) -> None:
      # Most presence data is sent to clients in the main presence
      # endpoint in response to the user's own presence; this results
      # data that is 1-2 minutes stale for who is online.  The flaw with
      # this plan is when a user comes back online and then immediately
      # sends a message, recipients may still see that user as offline!
      # We solve that by sending an immediate presence update clients.
      #
      # See https://zulip.readthedocs.io/en/latest/subsystems/presence.html for
      # internals documentation on presence.
      user_ids = active_user_ids(user_profile.realm_id)
      if len(user_ids) > settings.USER_LIMIT_FOR_SENDING_PRESENCE_UPDATE_EVENTS:
          # These immediate presence generate quadratic work for Tornado
          # (linear number of users in each event and the frequency of
          # users coming online grows linearly with userbase too).  In
          # organizations with thousands of users, this can overload
          # Tornado, especially if much of the realm comes online at the
          # same time.
          #
          # The utility of these live-presence updates goes down as
          # organizations get bigger (since one is much less likely to
          # be paying attention to the sidebar); so beyond a limit, we
          # stop sending them at all.
          return
  
      presence_dict = presence.to_dict()
      event = dict(
          type="presence",
          email=user_profile.email,
          user_id=user_profile.id,
          server_timestamp=time.time(),
          presence={presence_dict["client"]: presence_dict},
      )
      send_event(user_profile.realm, event, user_ids)
  
  
  def consolidate_client(client: Client) -> Client:
      # The web app reports a client as 'website'
      # The desktop app reports a client as ZulipDesktop
      # due to it setting a custom user agent. We want both
      # to count as web users
  
      # Alias ZulipDesktop to website
      if client.name in ["ZulipDesktop"]:
          return get_client("website")
      else:
          return client
  
  
  @statsd_increment("user_presence")
  def do_update_user_presence(
      user_profile: UserProfile, client: Client, log_time: datetime.datetime, status: int
  ) -> None:
      client = consolidate_client(client)
  
      defaults = dict(
          timestamp=log_time,
          status=status,
          realm_id=user_profile.realm_id,
      )
  
      (presence, created) = UserPresence.objects.get_or_create(
          user_profile=user_profile,
          client=client,
          defaults=defaults,
      )
  
      stale_status = (log_time - presence.timestamp) > datetime.timedelta(minutes=1, seconds=10)
      was_idle = presence.status == UserPresence.IDLE
      became_online = (status == UserPresence.ACTIVE) and (stale_status or was_idle)
  
      # If an object was created, it has already been saved.
      #
      # We suppress changes from ACTIVE to IDLE before stale_status is reached;
      # this protects us from the user having two clients open: one active, the
      # other idle. Without this check, we would constantly toggle their status
      # between the two states.
      if not created and stale_status or was_idle or status == presence.status:
          # The following block attempts to only update the "status"
          # field in the event that it actually changed.  This is
          # important to avoid flushing the UserPresence cache when the
          # data it would return to a client hasn't actually changed
          # (see the UserPresence post_save hook for details).
          presence.timestamp = log_time
          update_fields = ["timestamp"]
          if presence.status != status:
              presence.status = status
              update_fields.append("status")
          presence.save(update_fields=update_fields)
  
      if not user_profile.realm.presence_disabled and (created or became_online):
          send_presence_changed(user_profile, presence)
  
  
  def update_user_activity_interval(user_profile: UserProfile, log_time: datetime.datetime) -> None:
      event = {"user_profile_id": user_profile.id, "time": datetime_to_timestamp(log_time)}
      queue_json_publish("user_activity_interval", event)
  
  
  def update_user_presence(
      user_profile: UserProfile,
      client: Client,
      log_time: datetime.datetime,
      status: int,
      new_user_input: bool,
  ) -> None:
      event = {
          "user_profile_id": user_profile.id,
          "status": status,
          "time": datetime_to_timestamp(log_time),
          "client": client.name,
      }
  
      queue_json_publish("user_presence", event)
  
      if new_user_input:
          update_user_activity_interval(user_profile, log_time)
  
  
  def do_update_user_status(
      user_profile: UserProfile,
      away: Optional[bool],
      status_text: Optional[str],
      client_id: int,
      emoji_name: Optional[str],
      emoji_code: Optional[str],
      reaction_type: Optional[str],
  ) -> None:
      if away is None:
          status = None
      elif away:
          status = UserStatus.AWAY
      else:
          status = UserStatus.NORMAL
  
      realm = user_profile.realm
  
      update_user_status(
          user_profile_id=user_profile.id,
          status=status,
          status_text=status_text,
          client_id=client_id,
          emoji_name=emoji_name,
          emoji_code=emoji_code,
          reaction_type=reaction_type,
      )
  
      event = dict(
          type="user_status",
          user_id=user_profile.id,
      )
  
      if away is not None:
          event["away"] = away
  
      if status_text is not None:
          event["status_text"] = status_text
  
      if emoji_name is not None:
          event["emoji_name"] = emoji_name
          event["emoji_code"] = emoji_code
          event["reaction_type"] = reaction_type
      send_event(realm, event, active_user_ids(realm.id))
  
  
  @dataclass
  class ReadMessagesEvent:
      messages: List[int]
      all: bool
      type: str = field(default="update_message_flags", init=False)
      op: str = field(default="add", init=False)
      operation: str = field(default="add", init=False)
      flag: str = field(default="read", init=False)
  
  
  def do_mark_all_as_read(user_profile: UserProfile, client: Client) -> int:
      log_statsd_event("bankruptcy")
  
      # First, we clear mobile push notifications.  This is safer in the
      # event that the below logic times out and we're killed.
      all_push_message_ids = (
          UserMessage.objects.filter(
              user_profile=user_profile,
          )
          .extra(
              where=[UserMessage.where_active_push_notification()],
          )
          .values_list("message_id", flat=True)[0:10000]
      )
      do_clear_mobile_push_notifications_for_ids([user_profile.id], all_push_message_ids)
  
      msgs = UserMessage.objects.filter(user_profile=user_profile).extra(
          where=[UserMessage.where_unread()],
      )
  
      count = msgs.update(
          flags=F("flags").bitor(UserMessage.flags.read),
      )
  
      event = asdict(
          ReadMessagesEvent(
              messages=[],  # we don't send messages, since the client reloads anyway
              all=True,
          )
      )
      event_time = timezone_now()
  
      send_event(user_profile.realm, event, [user_profile.id])
  
      do_increment_logging_stat(
          user_profile, COUNT_STATS["messages_read::hour"], None, event_time, increment=count
      )
      do_increment_logging_stat(
          user_profile,
          COUNT_STATS["messages_read_interactions::hour"],
          None,
          event_time,
          increment=min(1, count),
      )
  
      return count
  
  
  def do_mark_stream_messages_as_read(
      user_profile: UserProfile, stream_recipient_id: int, topic_name: Optional[str] = None
  ) -> int:
      log_statsd_event("mark_stream_as_read")
  
      msgs = UserMessage.objects.filter(
          user_profile=user_profile,
      )
  
      msgs = msgs.filter(message__recipient_id=stream_recipient_id)
  
      if topic_name:
          msgs = filter_by_topic_name_via_message(
              query=msgs,
              topic_name=topic_name,
          )
  
      msgs = msgs.extra(
          where=[UserMessage.where_unread()],
      )
  
      message_ids = list(msgs.values_list("message_id", flat=True))
  
      count = msgs.update(
          flags=F("flags").bitor(UserMessage.flags.read),
      )
  
      event = asdict(
          ReadMessagesEvent(
              messages=message_ids,
              all=False,
          )
      )
      event_time = timezone_now()
  
      send_event(user_profile.realm, event, [user_profile.id])
      do_clear_mobile_push_notifications_for_ids([user_profile.id], message_ids)
  
      do_increment_logging_stat(
          user_profile, COUNT_STATS["messages_read::hour"], None, event_time, increment=count
      )
      do_increment_logging_stat(
          user_profile,
          COUNT_STATS["messages_read_interactions::hour"],
          None,
          event_time,
          increment=min(1, count),
      )
      return count
  
  
  def do_mark_muted_user_messages_as_read(
      user_profile: UserProfile,
      muted_user: UserProfile,
  ) -> int:
      messages = UserMessage.objects.filter(
          user_profile=user_profile, message__sender=muted_user
      ).extra(where=[UserMessage.where_unread()])
  
      message_ids = list(messages.values_list("message_id", flat=True))
  
      count = messages.update(
          flags=F("flags").bitor(UserMessage.flags.read),
      )
  
      event = asdict(
          ReadMessagesEvent(
              messages=message_ids,
              all=False,
          )
      )
      event_time = timezone_now()
  
      send_event(user_profile.realm, event, [user_profile.id])
      do_clear_mobile_push_notifications_for_ids([user_profile.id], message_ids)
  
      do_increment_logging_stat(
          user_profile, COUNT_STATS["messages_read::hour"], None, event_time, increment=count
      )
      do_increment_logging_stat(
          user_profile,
          COUNT_STATS["messages_read_interactions::hour"],
          None,
          event_time,
          increment=min(1, count),
      )
      return count
  
  
  def do_update_mobile_push_notification(
      message: Message,
      prior_mention_user_ids: Set[int],
      mentions_user_ids: Set[int],
      stream_push_user_ids: Set[int],
  ) -> None:
      # Called during the message edit code path to remove mobile push
      # notifications for users who are no longer mentioned following
      # the edit.  See #15428 for details.
      #
      # A perfect implementation would also support updating the message
      # in a sent notification if a message was edited to mention a
      # group rather than a user (or vice versa), though it is likely
      # not worth the effort to do such a change.
      if not message.is_stream_message():
          return
  
      remove_notify_users = prior_mention_user_ids - mentions_user_ids - stream_push_user_ids
      do_clear_mobile_push_notifications_for_ids(list(remove_notify_users), [message.id])
  
  
  def do_clear_mobile_push_notifications_for_ids(
      user_profile_ids: List[int], message_ids: List[int]
  ) -> None:
      if len(message_ids) == 0:
          return
  
      # This function supports clearing notifications for several users
      # only for the message-edit use case where we'll have a single message_id.
      assert len(user_profile_ids) == 1 or len(message_ids) == 1
  
      messages_by_user = defaultdict(list)
      notifications_to_update = list(
          UserMessage.objects.filter(
              message_id__in=message_ids,
              user_profile_id__in=user_profile_ids,
          )
          .extra(
              where=[UserMessage.where_active_push_notification()],
          )
          .values_list("user_profile_id", "message_id")
      )
  
      for (user_id, message_id) in notifications_to_update:
          messages_by_user[user_id].append(message_id)
  
      for (user_profile_id, event_message_ids) in messages_by_user.items():
          queue_json_publish(
              "missedmessage_mobile_notifications",
              {
                  "type": "remove",
                  "user_profile_id": user_profile_id,
                  "message_ids": event_message_ids,
              },
          )
  
  
  def do_update_message_flags(
      user_profile: UserProfile, client: Client, operation: str, flag: str, messages: List[int]
  ) -> int:
      valid_flags = [item for item in UserMessage.flags if item not in UserMessage.NON_API_FLAGS]
      if flag not in valid_flags:
          raise JsonableError(_("Invalid flag: '{}'").format(flag))
      if flag in UserMessage.NON_EDITABLE_FLAGS:
          raise JsonableError(_("Flag not editable: '{}'").format(flag))
      if operation not in ("add", "remove"):
          raise JsonableError(_("Invalid message flag operation: '{}'").format(operation))
      flagattr = getattr(UserMessage.flags, flag)
  
      msgs = UserMessage.objects.filter(user_profile=user_profile, message_id__in=messages)
      # This next block allows you to star any message, even those you
      # didn't receive (e.g. because you're looking at a public stream
      # you're not subscribed to, etc.).  The problem is that starring
      # is a flag boolean on UserMessage, and UserMessage rows are
      # normally created only when you receive a message to support
      # searching your personal history.  So we need to create one.  We
      # add UserMessage.flags.historical, so that features that need
      # "messages you actually received" can exclude these UserMessages.
      if msgs.count() == 0:
          if not len(messages) == 1:
              raise JsonableError(_("Invalid message(s)"))
          if flag != "starred":
              raise JsonableError(_("Invalid message(s)"))
          # Validate that the user could have read the relevant message
          message = access_message(user_profile, messages[0])[0]
  
          # OK, this is a message that you legitimately have access
          # to via narrowing to the stream it is on, even though you
          # didn't actually receive it.  So we create a historical,
          # read UserMessage message row for you to star.
          UserMessage.objects.create(
              user_profile=user_profile,
              message=message,
              flags=UserMessage.flags.historical | UserMessage.flags.read,
          )
  
      if operation == "add":
          count = msgs.update(flags=F("flags").bitor(flagattr))
      elif operation == "remove":
          count = msgs.update(flags=F("flags").bitand(~flagattr))
  
      event = {
          "type": "update_message_flags",
          "op": operation,
          "operation": operation,
          "flag": flag,
          "messages": messages,
          "all": False,
      }
      send_event(user_profile.realm, event, [user_profile.id])
  
      if flag == "read" and operation == "add":
          event_time = timezone_now()
          do_clear_mobile_push_notifications_for_ids([user_profile.id], messages)
  
          do_increment_logging_stat(
              user_profile, COUNT_STATS["messages_read::hour"], None, event_time, increment=count
          )
          do_increment_logging_stat(
              user_profile,
              COUNT_STATS["messages_read_interactions::hour"],
              None,
              event_time,
              increment=min(1, count),
          )
      return count
  
  
  class MessageUpdateUserInfoResult(TypedDict):
      message_user_ids: Set[int]
      mention_user_ids: Set[int]
  
  
  def maybe_send_resolve_topic_notifications(
      *,
      user_profile: UserProfile,
      stream: Stream,
      old_topic: str,
      new_topic: str,
  ) -> None:
      # Note that topics will have already been stripped in check_update_message.
      #
      # This logic is designed to treat removing a weird "✔ ✔✔ "
      # prefix as unresolving the topic.
      if old_topic.lstrip(RESOLVED_TOPIC_PREFIX) != new_topic.lstrip(RESOLVED_TOPIC_PREFIX):
          return
  
      if new_topic.startswith(RESOLVED_TOPIC_PREFIX) and not old_topic.startswith(
          RESOLVED_TOPIC_PREFIX
      ):
          notification_string = _("{user} has marked this topic as resolved.")
      elif old_topic.startswith(RESOLVED_TOPIC_PREFIX) and not new_topic.startswith(
          RESOLVED_TOPIC_PREFIX
      ):
          notification_string = _("{user} has marked this topic as unresolved.")
      else:
          # If there's some other weird topic that does not toggle the
          # state of "topic starts with RESOLVED_TOPIC_PREFIX", we do
          # nothing. Any other logic could result in cases where we send
          # these notifications in a non-alternating fashion.
          #
          # Note that it is still possible for an individual topic to
          # have multiple "This topic was marked as resolved"
          # notifications in a row: one can send new messages to the
          # pre-resolve topic and then resolve the topic created that
          # way to get multiple in the resolved topic. And then an
          # administrator can the messages in between. We consider this
          # to be a fundamental risk of irresponsible message deletion,
          # not a bug with the "resolve topics" feature.
          return
  
      sender = get_system_bot(settings.NOTIFICATION_BOT, user_profile.realm_id)
      user_mention = f"@_**{user_profile.full_name}|{user_profile.id}**"
      with override_language(stream.realm.default_language):
          internal_send_stream_message(
              sender,
              stream,
              new_topic,
              notification_string.format(
                  user=user_mention,
              ),
          )
  
  
  def send_message_moved_breadcrumbs(
      user_profile: UserProfile,
      old_stream: Stream,
      old_topic: str,
      old_thread_notification_string: Optional[str],
      new_stream: Stream,
      new_topic: Optional[str],
      new_thread_notification_string: Optional[str],
  ) -> None:
      # Since moving content between streams is highly disruptive,
      # it's worth adding a couple tombstone messages showing what
      # happened.
      sender = get_system_bot(settings.NOTIFICATION_BOT, old_stream.realm_id)
  
      if new_topic is None:
          new_topic = old_topic
  
      user_mention = f"@_**{user_profile.full_name}|{user_profile.id}**"
      old_topic_link = f"#**{old_stream.name}>{old_topic}**"
      new_topic_link = f"#**{new_stream.name}>{new_topic}**"
  
      if new_thread_notification_string is not None:
          with override_language(new_stream.realm.default_language):
              internal_send_stream_message(
                  sender,
                  new_stream,
                  new_topic,
                  new_thread_notification_string.format(
                      old_location=old_topic_link,
                      user=user_mention,
                  ),
              )
  
      if old_thread_notification_string is not None:
          with override_language(old_stream.realm.default_language):
              # Send a notification to the old stream that the topic was moved.
              internal_send_stream_message(
                  sender,
                  old_stream,
                  old_topic,
                  old_thread_notification_string.format(
                      user=user_mention,
                      new_location=new_topic_link,
                  ),
              )
  
  
  def get_user_info_for_message_updates(message_id: int) -> MessageUpdateUserInfoResult:
  
      # We exclude UserMessage.flags.historical rows since those
      # users did not receive the message originally, and thus
      # probably are not relevant for reprocessed alert_words,
      # mentions and similar rendering features.  This may be a
      # decision we change in the future.
      query = UserMessage.objects.filter(
          message=message_id,
          flags=~UserMessage.flags.historical,
      ).values("user_profile_id", "flags")
      rows = list(query)
  
      message_user_ids = {row["user_profile_id"] for row in rows}
  
      mask = UserMessage.flags.mentioned | UserMessage.flags.wildcard_mentioned
  
      mention_user_ids = {row["user_profile_id"] for row in rows if int(row["flags"]) & mask}
  
      return dict(
          message_user_ids=message_user_ids,
          mention_user_ids=mention_user_ids,
      )
  
  
  def update_user_message_flags(
      rendering_result: MessageRenderingResult, ums: Iterable[UserMessage]
  ) -> None:
      wildcard = rendering_result.mentions_wildcard
      mentioned_ids = rendering_result.mentions_user_ids
      ids_with_alert_words = rendering_result.user_ids_with_alert_words
      changed_ums: Set[UserMessage] = set()
  
      def update_flag(um: UserMessage, should_set: bool, flag: int) -> None:
          if should_set:
              if not (um.flags & flag):
                  um.flags |= flag
                  changed_ums.add(um)
          else:
              if um.flags & flag:
                  um.flags &= ~flag
                  changed_ums.add(um)
  
      for um in ums:
          has_alert_word = um.user_profile_id in ids_with_alert_words
          update_flag(um, has_alert_word, UserMessage.flags.has_alert_word)
  
          mentioned = um.user_profile_id in mentioned_ids
          update_flag(um, mentioned, UserMessage.flags.mentioned)
  
          update_flag(um, wildcard, UserMessage.flags.wildcard_mentioned)
  
      for um in changed_ums:
          um.save(update_fields=["flags"])
  
  
  def update_to_dict_cache(
      changed_messages: List[Message], realm_id: Optional[int] = None
  ) -> List[int]:
      """Updates the message as stored in the to_dict cache (for serving
      messages)."""
      items_for_remote_cache = {}
      message_ids = []
      changed_messages_to_dict = MessageDict.to_dict_uncached(changed_messages, realm_id)
      for msg_id, msg in changed_messages_to_dict.items():
          message_ids.append(msg_id)
          key = to_dict_cache_key_id(msg_id)
          items_for_remote_cache[key] = (msg,)
  
      cache_set_many(items_for_remote_cache)
      return message_ids
  
  
  def do_update_embedded_data(
      user_profile: UserProfile,
      message: Message,
      content: Optional[str],
      rendering_result: MessageRenderingResult,
  ) -> None:
      event: Dict[str, Any] = {"type": "update_message", "message_id": message.id}
      changed_messages = [message]
      rendered_content: Optional[str] = None
  
      ums = UserMessage.objects.filter(message=message.id)
  
      if content is not None:
          update_user_message_flags(rendering_result, ums)
          rendered_content = rendering_result.rendered_content
          message.rendered_content = rendered_content
          message.rendered_content_version = markdown_version
          event["content"] = content
          event["rendered_content"] = rendered_content
  
      message.save(update_fields=["content", "rendered_content"])
  
      event["message_ids"] = update_to_dict_cache(changed_messages)
  
      def user_info(um: UserMessage) -> Dict[str, Any]:
          return {
              "id": um.user_profile_id,
              "flags": um.flags_list(),
          }
  
      send_event(user_profile.realm, event, list(map(user_info, ums)))
  
  
  class DeleteMessagesEvent(TypedDict, total=False):
      type: str
      message_ids: List[int]
      message_type: str
      topic: str
      stream_id: int
  
  
  # We use transaction.atomic to support select_for_update in the attachment codepath.
  @transaction.atomic
  def do_update_message(
      user_profile: UserProfile,
      target_message: Message,
      new_stream: Optional[Stream],
      topic_name: Optional[str],
      propagate_mode: str,
      send_notification_to_old_thread: bool,
      send_notification_to_new_thread: bool,
      content: Optional[str],
      rendering_result: Optional[MessageRenderingResult],
      prior_mention_user_ids: Set[int],
      mention_data: Optional[MentionData] = None,
  ) -> int:
      """
      The main function for message editing.  A message edit event can
      modify:
      * the message's content (in which case the caller will have
        set both content and rendered_content),
      * the topic, in which case the caller will have set topic_name
      * or both
  
      With topic edits, propagate_mode determines whether other message
      also have their topics edited.
      """
      timestamp = timezone_now()
      target_message.last_edit_time = timestamp
  
      event: Dict[str, Any] = {
          "type": "update_message",
          "user_id": user_profile.id,
          "edit_timestamp": datetime_to_timestamp(timestamp),
          "message_id": target_message.id,
      }
  
      edit_history_event: Dict[str, Any] = {
          "user_id": user_profile.id,
          "timestamp": event["edit_timestamp"],
      }
  
      changed_messages = [target_message]
  
      realm = user_profile.realm
  
      stream_being_edited = None
      if target_message.is_stream_message():
          stream_id = target_message.recipient.type_id
          stream_being_edited = get_stream_by_id_in_realm(stream_id, realm)
          event["stream_name"] = stream_being_edited.name
  
      ums = UserMessage.objects.filter(message=target_message.id)
  
      if content is not None:
          assert rendering_result is not None
  
          # mention_data is required if there's a content edit.
          assert mention_data is not None
  
          # add data from group mentions to mentions_user_ids.
          for group_id in rendering_result.mentions_user_group_ids:
              members = mention_data.get_group_members(group_id)
              rendering_result.mentions_user_ids.update(members)
  
          update_user_message_flags(rendering_result, ums)
  
          # One could imagine checking realm.allow_edit_history here and
          # modifying the events based on that setting, but doing so
          # doesn't really make sense.  We need to send the edit event
          # to clients regardless, and a client already had access to
          # the original/pre-edit content of the message anyway.  That
          # setting must be enforced on the client side, and making a
          # change here simply complicates the logic for clients parsing
          # edit history events.
          event["orig_content"] = target_message.content
          event["orig_rendered_content"] = target_message.rendered_content
          edit_history_event["prev_content"] = target_message.content
          edit_history_event["prev_rendered_content"] = target_message.rendered_content
          edit_history_event[
              "prev_rendered_content_version"
          ] = target_message.rendered_content_version
          target_message.content = content
          target_message.rendered_content = rendering_result.rendered_content
          target_message.rendered_content_version = markdown_version
          event["content"] = content
          event["rendered_content"] = rendering_result.rendered_content
          event["prev_rendered_content_version"] = target_message.rendered_content_version
          event["is_me_message"] = Message.is_status_message(
              content, rendering_result.rendered_content
          )
  
          # target_message.has_image and target_message.has_link will have been
          # already updated by Markdown rendering in the caller.
          target_message.has_attachment = check_attachment_reference_change(
              target_message, rendering_result
          )
  
          if target_message.is_stream_message():
              if topic_name is not None:
                  new_topic_name = topic_name
              else:
                  new_topic_name = target_message.topic_name()
  
              stream_topic: Optional[StreamTopicTarget] = StreamTopicTarget(
                  stream_id=stream_id,
                  topic_name=new_topic_name,
              )
          else:
              stream_topic = None
  
          info = get_recipient_info(
              realm_id=realm.id,
              recipient=target_message.recipient,
              sender_id=target_message.sender_id,
              stream_topic=stream_topic,
              possible_wildcard_mention=mention_data.message_has_wildcards(),
          )
  
          event["online_push_user_ids"] = list(info["online_push_user_ids"])
          event["pm_mention_push_disabled_user_ids"] = list(info["pm_mention_push_disabled_user_ids"])
          event["pm_mention_email_disabled_user_ids"] = list(
              info["pm_mention_email_disabled_user_ids"]
          )
          event["stream_push_user_ids"] = list(info["stream_push_user_ids"])
          event["stream_email_user_ids"] = list(info["stream_email_user_ids"])
          event["muted_sender_user_ids"] = list(info["muted_sender_user_ids"])
          event["prior_mention_user_ids"] = list(prior_mention_user_ids)
          event["presence_idle_user_ids"] = filter_presence_idle_user_ids(info["active_user_ids"])
          if rendering_result.mentions_wildcard:
              event["wildcard_mention_user_ids"] = list(info["wildcard_mention_user_ids"])
          else:
              event["wildcard_mention_user_ids"] = []
  
          do_update_mobile_push_notification(
              target_message,
              prior_mention_user_ids,
              rendering_result.mentions_user_ids,
              info["stream_push_user_ids"],
          )
  
      if topic_name is not None or new_stream is not None:
          orig_topic_name = target_message.topic_name()
          event["propagate_mode"] = propagate_mode
          event["stream_id"] = target_message.recipient.type_id
  
      if new_stream is not None:
          assert content is None
          assert target_message.is_stream_message()
          assert stream_being_edited is not None
  
          edit_history_event["prev_stream"] = stream_being_edited.id
          event[ORIG_TOPIC] = orig_topic_name
          target_message.recipient_id = new_stream.recipient_id
  
          event["new_stream_id"] = new_stream.id
          event["propagate_mode"] = propagate_mode
  
          # When messages are moved from one stream to another, some
          # users may lose access to those messages, including guest
          # users and users not subscribed to the new stream (if it is a
          # private stream).  For those users, their experience is as
          # though the messages were deleted, and we should send a
          # delete_message event to them instead.
  
          subs_to_old_stream = get_active_subscriptions_for_stream_id(
              stream_id, include_deactivated_users=True
          ).select_related("user_profile")
          subs_to_new_stream = list(
              get_active_subscriptions_for_stream_id(
                  new_stream.id, include_deactivated_users=True
              ).select_related("user_profile")
          )
  
          old_stream_sub_ids = [user.user_profile_id for user in subs_to_old_stream]
          new_stream_sub_ids = [user.user_profile_id for user in subs_to_new_stream]
  
          # Get users who aren't subscribed to the new_stream.
          subs_losing_usermessages = [
              sub for sub in subs_to_old_stream if sub.user_profile_id not in new_stream_sub_ids
          ]
          # Users who can longer access the message without some action
          # from administrators.
          subs_losing_access = [
              sub
              for sub in subs_losing_usermessages
              if sub.user_profile.is_guest or not new_stream.is_public()
          ]
          ums = ums.exclude(
              user_profile_id__in=[sub.user_profile_id for sub in subs_losing_usermessages]
          )
  
          subs_gaining_usermessages = []
          if not new_stream.is_history_public_to_subscribers():
              # For private streams, with history not public to subscribers,
              # We find out users who are not present in the msgs' old stream
              # and create new UserMessage for these users so that they can
              # access this message.
              subs_gaining_usermessages += [
                  user_id for user_id in new_stream_sub_ids if user_id not in old_stream_sub_ids
              ]
  
      if topic_name is not None:
          topic_name = truncate_topic(topic_name)
          target_message.set_topic_name(topic_name)
  
          # These fields have legacy field names.
          event[ORIG_TOPIC] = orig_topic_name
          event[TOPIC_NAME] = topic_name
          event[TOPIC_LINKS] = topic_links(target_message.sender.realm_id, topic_name)
          edit_history_event[LEGACY_PREV_TOPIC] = orig_topic_name
  
      update_edit_history(target_message, timestamp, edit_history_event)
  
      delete_event_notify_user_ids: List[int] = []
      if propagate_mode in ["change_later", "change_all"]:
          assert topic_name is not None or new_stream is not None
          assert stream_being_edited is not None
  
          # Other messages should only get topic/stream fields in their edit history.
          topic_only_edit_history_event = {
              k: v
              for (k, v) in edit_history_event.items()
              if k
              not in [
                  "prev_content",
                  "prev_rendered_content",
                  "prev_rendered_content_version",
              ]
          }
  
          messages_list = update_messages_for_topic_edit(
              acting_user=user_profile,
              edited_message=target_message,
              propagate_mode=propagate_mode,
              orig_topic_name=orig_topic_name,
              topic_name=topic_name,
              new_stream=new_stream,
              old_stream=stream_being_edited,
              edit_history_event=topic_only_edit_history_event,
              last_edit_time=timestamp,
          )
          changed_messages += messages_list
  
          if new_stream is not None:
              assert stream_being_edited is not None
              changed_message_ids = [msg.id for msg in changed_messages]
  
              if subs_gaining_usermessages:
                  ums_to_create = []
                  for message_id in changed_message_ids:
                      for user_profile_id in subs_gaining_usermessages:
                          # The fact that the user didn't have a UserMessage originally means we can infer that the user
                          # was not mentioned in the original message (even if mention syntax was present, it would not
                          # take effect for a user who was not subscribed). If we were editing the message's content, we
                          # would rerender the message and then use the new stream's data to determine whether this is
                          # a mention of a subscriber; but as we are not doing so, we choose to preserve the "was this
                          # mention syntax an actual mention" decision made during the original rendering for implementation
                          # simplicity. As a result, the only flag to consider applying here is read.
                          um = UserMessageLite(
                              user_profile_id=user_profile_id,
                              message_id=message_id,
                              flags=UserMessage.flags.read,
                          )
                          ums_to_create.append(um)
                  bulk_insert_ums(ums_to_create)
  
              # Delete UserMessage objects for users who will no
              # longer have access to these messages.  Note: This could be
              # very expensive, since it's N guest users x M messages.
              UserMessage.objects.filter(
                  user_profile_id__in=[sub.user_profile_id for sub in subs_losing_usermessages],
                  message_id__in=changed_message_ids,
              ).delete()
  
              delete_event: DeleteMessagesEvent = {
                  "type": "delete_message",
                  "message_ids": changed_message_ids,
                  "message_type": "stream",
                  "stream_id": stream_being_edited.id,
                  "topic": orig_topic_name,
              }
              delete_event_notify_user_ids = [sub.user_profile_id for sub in subs_losing_access]
              send_event(user_profile.realm, delete_event, delete_event_notify_user_ids)
  
      # This does message.save(update_fields=[...])
      save_message_for_edit_use_case(message=target_message)
  
      realm_id: Optional[int] = None
      if stream_being_edited is not None:
          realm_id = stream_being_edited.realm_id
  
      event["message_ids"] = update_to_dict_cache(changed_messages, realm_id)
  
      def user_info(um: UserMessage) -> Dict[str, Any]:
          return {
              "id": um.user_profile_id,
              "flags": um.flags_list(),
          }
  
      # The following blocks arranges that users who are subscribed to a
      # stream and can see history from before they subscribed get
      # live-update when old messages are edited (e.g. if the user does
      # a topic edit themself).
      #
      # We still don't send an update event to users who are not
      # subscribed to this stream and don't have a UserMessage row. This
      # means if a non-subscriber is viewing the narrow, they won't get
      # a real-time updates. This is a balance between sending
      # message-edit notifications for every public stream to every user
      # in the organization (too expansive, and also not what we do for
      # newly sent messages anyway) and having magical live-updates
      # where possible.
      users_to_be_notified = list(map(user_info, ums))
      if stream_being_edited is not None:
          if stream_being_edited.is_history_public_to_subscribers:
              subscriptions = get_active_subscriptions_for_stream_id(
                  stream_id, include_deactivated_users=False
              )
              # We exclude long-term idle users, since they by
              # definition have no active clients.
              subscriptions = subscriptions.exclude(user_profile__long_term_idle=True)
              # Remove duplicates by excluding the id of users already
              # in users_to_be_notified list.  This is the case where a
              # user both has a UserMessage row and is a current
              # Subscriber
              subscriptions = subscriptions.exclude(
                  user_profile_id__in=[um.user_profile_id for um in ums]
              )
  
              if new_stream is not None:
                  assert delete_event_notify_user_ids is not None
                  subscriptions = subscriptions.exclude(
                      user_profile_id__in=delete_event_notify_user_ids
                  )
  
              # All users that are subscribed to the stream must be
              # notified when a message is edited
              subscriber_ids = set(subscriptions.values_list("user_profile_id", flat=True))
  
              if new_stream is not None:
                  # TODO: Guest users don't see the new moved topic
                  # unless breadcrumb message for new stream is
                  # enabled. Excluding these users from receiving this
                  # event helps us avoid a error trackeback for our
                  # clients. We should figure out a way to inform the
                  # guest users of this new topic if sending a 'message'
                  # event for these messages is not an option.
                  #
                  # Don't send this event to guest subs who are not
                  # subscribers of the old stream but are subscribed to
                  # the new stream; clients will be confused.
                  old_stream_unsubbed_guests = [
                      sub
                      for sub in subs_to_new_stream
                      if sub.user_profile.is_guest and sub.user_profile_id not in subscriber_ids
                  ]
                  subscriptions = subscriptions.exclude(
                      user_profile_id__in=[sub.user_profile_id for sub in old_stream_unsubbed_guests]
                  )
                  subscriber_ids = set(subscriptions.values_list("user_profile_id", flat=True))
  
              users_to_be_notified += list(map(subscriber_info, sorted(list(subscriber_ids))))
  
      send_event(user_profile.realm, event, users_to_be_notified)
  
      if len(changed_messages) > 0 and new_stream is not None and stream_being_edited is not None:
          # Notify users that the topic was moved.
          old_thread_notification_string = None
          if send_notification_to_old_thread:
              old_thread_notification_string = _("This topic was moved by {user} to {new_location}")
  
          new_thread_notification_string = None
          if send_notification_to_new_thread:
              new_thread_notification_string = _(
                  "This topic was moved here from {old_location} by {user}"
              )
  
          send_message_moved_breadcrumbs(
              user_profile,
              stream_being_edited,
              orig_topic_name,
              old_thread_notification_string,
              new_stream,
              topic_name,
              new_thread_notification_string,
          )
  
      if (
          topic_name is not None
          and new_stream is None
          and content is None
          and len(changed_messages) > 0
      ):
          assert stream_being_edited is not None
          maybe_send_resolve_topic_notifications(
              user_profile=user_profile,
              stream=stream_being_edited,
              old_topic=orig_topic_name,
              new_topic=topic_name,
          )
  
      return len(changed_messages)
  
  
  def do_delete_messages(realm: Realm, messages: Iterable[Message]) -> None:
      # messages in delete_message event belong to the same topic
      # or is a single private message, as any other behaviour is not possible with
      # the current callers to this method.
      messages = list(messages)
      message_ids = [message.id for message in messages]
      if not message_ids:
          return
  
      event: DeleteMessagesEvent = {
          "type": "delete_message",
          "message_ids": message_ids,
      }
  
      sample_message = messages[0]
      message_type = "stream"
      users_to_notify = []
      if not sample_message.is_stream_message():
          assert len(messages) == 1
          message_type = "private"
          ums = UserMessage.objects.filter(message_id__in=message_ids)
          users_to_notify = [um.user_profile_id for um in ums]
          archiving_chunk_size = retention.MESSAGE_BATCH_SIZE
  
      if message_type == "stream":
          stream_id = sample_message.recipient.type_id
          event["stream_id"] = stream_id
          event["topic"] = sample_message.topic_name()
          subscriptions = get_active_subscriptions_for_stream_id(
              stream_id, include_deactivated_users=False
          )
          # We exclude long-term idle users, since they by definition have no active clients.
          subscriptions = subscriptions.exclude(user_profile__long_term_idle=True)
          users_to_notify = list(subscriptions.values_list("user_profile_id", flat=True))
          archiving_chunk_size = retention.STREAM_MESSAGE_BATCH_SIZE
  
      move_messages_to_archive(message_ids, realm=realm, chunk_size=archiving_chunk_size)
  
      event["message_type"] = message_type
      transaction.on_commit(lambda: send_event(realm, event, users_to_notify))
  
  
  def do_delete_messages_by_sender(user: UserProfile) -> None:
      message_ids = list(
          Message.objects.filter(sender=user).values_list("id", flat=True).order_by("id")
      )
      if message_ids:
          move_messages_to_archive(message_ids, chunk_size=retention.STREAM_MESSAGE_BATCH_SIZE)
  
  
  def get_streams_traffic(stream_ids: Set[int]) -> Dict[int, int]:
      stat = COUNT_STATS["messages_in_stream:is_bot:day"]
      traffic_from = timezone_now() - datetime.timedelta(days=28)
  
      query = StreamCount.objects.filter(property=stat.property, end_time__gt=traffic_from)
      query = query.filter(stream_id__in=stream_ids)
  
      traffic_list = query.values("stream_id").annotate(value=Sum("value"))
      traffic_dict = {}
      for traffic in traffic_list:
          traffic_dict[traffic["stream_id"]] = traffic["value"]
  
      return traffic_dict
  
  
  def round_to_2_significant_digits(number: int) -> int:
      return int(round(number, 2 - len(str(number))))
  
  
  STREAM_TRAFFIC_CALCULATION_MIN_AGE_DAYS = 7
  
  
  def get_average_weekly_stream_traffic(
      stream_id: int, stream_date_created: datetime.datetime, recent_traffic: Dict[int, int]
  ) -> Optional[int]:
      try:
          stream_traffic = recent_traffic[stream_id]
      except KeyError:
          stream_traffic = 0
  
      stream_age = (timezone_now() - stream_date_created).days
  
      if stream_age >= 28:
          average_weekly_traffic = int(stream_traffic // 4)
      elif stream_age >= STREAM_TRAFFIC_CALCULATION_MIN_AGE_DAYS:
          average_weekly_traffic = int(stream_traffic * 7 // stream_age)
      else:
          return None
  
      if average_weekly_traffic == 0 and stream_traffic > 0:
          average_weekly_traffic = 1
  
      return round_to_2_significant_digits(average_weekly_traffic)
  
  
  def get_web_public_subs(realm: Realm) -> SubscriptionInfo:
      color_idx = 0
  
      def get_next_color() -> str:
          nonlocal color_idx
          color = STREAM_ASSIGNMENT_COLORS[color_idx]
          color_idx = (color_idx + 1) % len(STREAM_ASSIGNMENT_COLORS)
          return color
  
      subscribed = []
      for stream in Stream.objects.filter(realm=realm, is_web_public=True, deactivated=False):
          stream_dict = stream.to_dict()
  
          # Add versions of the Subscription fields based on a simulated
          # new user subscription set.
          stream_dict["is_muted"] = False
          stream_dict["color"] = get_next_color()
          stream_dict["desktop_notifications"] = True
          stream_dict["audible_notifications"] = True
          stream_dict["push_notifications"] = True
          stream_dict["email_notifications"] = True
          stream_dict["pin_to_top"] = False
          stream_weekly_traffic = get_average_weekly_stream_traffic(
              stream.id, stream.date_created, {}
          )
          stream_dict["stream_weekly_traffic"] = stream_weekly_traffic
          stream_dict["email_address"] = ""
          subscribed.append(stream_dict)
  
      return SubscriptionInfo(
          subscriptions=subscribed,
          unsubscribed=[],
          never_subscribed=[],
      )
  
  
  def build_stream_dict_for_sub(
      user: UserProfile,
      sub_dict: RawSubscriptionDict,
      raw_stream_dict: RawStreamDict,
      recent_traffic: Dict[int, int],
  ) -> Dict[str, object]:
      # We first construct a dictionary based on the standard Stream
      # and Subscription models' API_FIELDS.
      result = {}
      for field_name in Stream.API_FIELDS:
          if field_name == "id":
              result["stream_id"] = raw_stream_dict["id"]
              continue
          elif field_name == "date_created":
              result["date_created"] = datetime_to_timestamp(raw_stream_dict[field_name])
              continue
          result[field_name] = raw_stream_dict[field_name]
  
      # Copy Subscription.API_FIELDS.
      for field_name in Subscription.API_FIELDS:
          result[field_name] = sub_dict[field_name]
  
      # Backwards-compatibility for clients that haven't been
      # updated for the in_home_view => is_muted API migration.
      result["in_home_view"] = not result["is_muted"]
  
      # Backwards-compatibility for clients that haven't been
      # updated for the is_announcement_only -> stream_post_policy
      # migration.
      result["is_announcement_only"] = (
          raw_stream_dict["stream_post_policy"] == Stream.STREAM_POST_POLICY_ADMINS
      )
  
      # Add a few computed fields not directly from the data models.
      result["stream_weekly_traffic"] = get_average_weekly_stream_traffic(
          raw_stream_dict["id"], raw_stream_dict["date_created"], recent_traffic
      )
  
      result["email_address"] = encode_email_address_helper(
          raw_stream_dict["name"], raw_stream_dict["email_token"], show_sender=True
      )
  
      # Our caller may add a subscribers field.
      return result
  
  
  def build_stream_dict_for_never_sub(
      raw_stream_dict: RawStreamDict,
      recent_traffic: Dict[int, int],
  ) -> Dict[str, object]:
      result = {}
      for field_name in Stream.API_FIELDS:
          if field_name == "id":
              result["stream_id"] = raw_stream_dict["id"]
              continue
          elif field_name == "date_created":
              result["date_created"] = datetime_to_timestamp(raw_stream_dict[field_name])
              continue
          result[field_name] = raw_stream_dict[field_name]
  
      result["stream_weekly_traffic"] = get_average_weekly_stream_traffic(
          raw_stream_dict["id"], raw_stream_dict["date_created"], recent_traffic
      )
  
      # Backwards-compatibility addition of removed field.
      result["is_announcement_only"] = (
          raw_stream_dict["stream_post_policy"] == Stream.STREAM_POST_POLICY_ADMINS
      )
  
      # Our caller may add a subscribers field.
      return result
  
  
  # In general, it's better to avoid using .values() because it makes
  # the code pretty ugly, but in this case, it has significant
  # performance impact for loading / for users with large numbers of
  # subscriptions, so it's worth optimizing.
  def gather_subscriptions_helper(
      user_profile: UserProfile,
      include_subscribers: bool = True,
  ) -> SubscriptionInfo:
      realm = user_profile.realm
      all_streams: QuerySet[RawStreamDict] = get_active_streams(realm).values(
          *Stream.API_FIELDS,
          # The realm_id and recipient_id are generally not needed in the API.
          "realm_id",
          "recipient_id",
          # email_token isn't public to some users with access to
          # the stream, so doesn't belong in API_FIELDS.
          "email_token",
      )
      recip_id_to_stream_id: Dict[int, int] = {
          stream["recipient_id"]: stream["id"] for stream in all_streams
      }
      all_streams_map: Dict[int, RawStreamDict] = {stream["id"]: stream for stream in all_streams}
  
      sub_dicts_query: Iterable[RawSubscriptionDict] = (
          get_stream_subscriptions_for_user(user_profile)
          .values(
              *Subscription.API_FIELDS,
              "recipient_id",
              "active",
          )
          .order_by("recipient_id")
      )
  
      # We only care about subscriptions for active streams.
      sub_dicts: List[RawSubscriptionDict] = [
          sub_dict
          for sub_dict in sub_dicts_query
          if recip_id_to_stream_id.get(sub_dict["recipient_id"])
      ]
  
      def get_stream_id(sub_dict: RawSubscriptionDict) -> int:
          return recip_id_to_stream_id[sub_dict["recipient_id"]]
  
      traffic_stream_ids = {get_stream_id(sub_dict) for sub_dict in sub_dicts}
      recent_traffic = get_streams_traffic(stream_ids=traffic_stream_ids)
  
      # Okay, now we finally get to populating our main results, which
      # will be these three lists.
      subscribed = []
      unsubscribed = []
      never_subscribed = []
  
      sub_unsub_stream_ids = set()
      for sub_dict in sub_dicts:
          stream_id = get_stream_id(sub_dict)
          sub_unsub_stream_ids.add(stream_id)
          raw_stream_dict = all_streams_map[stream_id]
  
          stream_dict = build_stream_dict_for_sub(
              user=user_profile,
              sub_dict=sub_dict,
              raw_stream_dict=raw_stream_dict,
              recent_traffic=recent_traffic,
          )
  
          # is_active is represented in this structure by which list we include it in.
          is_active = sub_dict["active"]
          if is_active:
              subscribed.append(stream_dict)
          else:
              unsubscribed.append(stream_dict)
  
      if user_profile.can_access_public_streams():
          never_subscribed_stream_ids = set(all_streams_map) - sub_unsub_stream_ids
      else:
          web_public_stream_ids = {stream["id"] for stream in all_streams if stream["is_web_public"]}
          never_subscribed_stream_ids = web_public_stream_ids - sub_unsub_stream_ids
  
      never_subscribed_streams = [
          all_streams_map[stream_id] for stream_id in never_subscribed_stream_ids
      ]
  
      for raw_stream_dict in never_subscribed_streams:
          is_public = not raw_stream_dict["invite_only"]
          if is_public or user_profile.is_realm_admin:
              stream_dict = build_stream_dict_for_never_sub(
                  raw_stream_dict=raw_stream_dict, recent_traffic=recent_traffic
              )
  
              never_subscribed.append(stream_dict)
  
      if include_subscribers:
          # The highly optimized bulk_get_subscriber_user_ids wants to know which
          # streams we are subscribed to, for validation purposes, and it uses that
          # info to know if it's allowed to find OTHER subscribers.
          subscribed_stream_ids = {
              get_stream_id(sub_dict) for sub_dict in sub_dicts if sub_dict["active"]
          }
  
          subscriber_map = bulk_get_subscriber_user_ids(
              all_streams,
              user_profile,
              subscribed_stream_ids,
          )
  
          for lst in [subscribed, unsubscribed, never_subscribed]:
              for stream_dict in lst:
                  assert isinstance(stream_dict["stream_id"], int)
                  stream_id = stream_dict["stream_id"]
                  stream_dict["subscribers"] = subscriber_map[stream_id]
  
      return SubscriptionInfo(
          subscriptions=sorted(subscribed, key=lambda x: x["name"]),
          unsubscribed=sorted(unsubscribed, key=lambda x: x["name"]),
          never_subscribed=sorted(never_subscribed, key=lambda x: x["name"]),
      )
  
  
  def gather_subscriptions(
      user_profile: UserProfile,
      include_subscribers: bool = False,
  ) -> Tuple[List[Dict[str, Any]], List[Dict[str, Any]]]:
      helper_result = gather_subscriptions_helper(
          user_profile,
          include_subscribers=include_subscribers,
      )
      subscribed = helper_result.subscriptions
      unsubscribed = helper_result.unsubscribed
      return (subscribed, unsubscribed)
  
  
  class ActivePresenceIdleUserData(TypedDict):
      alerted: bool
      notifications_data: UserMessageNotificationsData
  
  
  def get_active_presence_idle_user_ids(
      realm: Realm,
      sender_id: int,
      active_users_data: List[ActivePresenceIdleUserData],
  ) -> List[int]:
      """
      Given a list of active_user_ids, we build up a subset
      of those users who fit these criteria:
  
          * They are likely to need notifications.
          * They are no longer "present" according to the
            UserPresence table.
      """
  
      if realm.presence_disabled:
          return []
  
      user_ids = set()
      for user_data in active_users_data:
          user_notifications_data: UserMessageNotificationsData = user_data["notifications_data"]
          alerted = user_data["alerted"]
  
          # We only need to know the presence idle state for a user if this message would be notifiable
          # for them if they were indeed idle. Only including those users in the calculation below is a
          # very important optimization for open communities with many inactive users.
          if user_notifications_data.is_notifiable(sender_id, idle=True) or alerted:
              user_ids.add(user_notifications_data.user_id)
  
      return filter_presence_idle_user_ids(user_ids)
  
  
  def filter_presence_idle_user_ids(user_ids: Set[int]) -> List[int]:
      # Given a set of user IDs (the recipients of a message), accesses
      # the UserPresence table to determine which of these users are
      # currently idle and should potentially get email notifications
      # (and push notifications with with
      # user_profile.enable_online_push_notifications=False).
      #
      # We exclude any presence data from ZulipMobile for the purpose of
      # triggering these notifications; the mobile app can more
      # effectively do its own client-side filtering of notification
      # sounds/etc. for the case that the user is actively doing a PM
      # conversation in the app.
  
      if not user_ids:
          return []
  
      # Matches presence.js constant
      OFFLINE_THRESHOLD_SECS = 140
  
      recent = timezone_now() - datetime.timedelta(seconds=OFFLINE_THRESHOLD_SECS)
      rows = (
          UserPresence.objects.filter(
              user_profile_id__in=user_ids,
              status=UserPresence.ACTIVE,
              timestamp__gte=recent,
          )
          .exclude(client__name="ZulipMobile")
          .distinct("user_profile_id")
          .values("user_profile_id")
      )
      active_user_ids = {row["user_profile_id"] for row in rows}
      idle_user_ids = user_ids - active_user_ids
      return sorted(idle_user_ids)
  
  
  def do_send_confirmation_email(
      invitee: PreregistrationUser, referrer: UserProfile, email_language: str
  ) -> str:
      """
      Send the confirmation/welcome e-mail to an invited user.
      """
      activation_url = create_confirmation_link(invitee, Confirmation.INVITATION)
      context = {
          "referrer_full_name": referrer.full_name,
          "referrer_email": referrer.delivery_email,
          "activate_url": activation_url,
          "referrer_realm_name": referrer.realm.name,
      }
      send_email(
          "zerver/emails/invitation",
          to_emails=[invitee.email],
          from_address=FromAddress.tokenized_no_reply_address(),
          language=email_language,
          context=context,
          realm=referrer.realm,
      )
      return activation_url
  
  
  def email_not_system_bot(email: str) -> None:
      if is_cross_realm_bot_email(email):
          msg = email_reserved_for_system_bots_error(email)
          code = msg
          raise ValidationError(
              msg,
              code=code,
              params=dict(deactivated=False),
          )
  
  
  def estimate_recent_invites(realms: Collection[Realm], *, days: int) -> int:
      """An upper bound on the number of invites sent in the last `days` days"""
      recent_invites = RealmCount.objects.filter(
          realm__in=realms,
          property="invites_sent::day",
          end_time__gte=timezone_now() - datetime.timedelta(days=days),
      ).aggregate(Sum("value"))["value__sum"]
      if recent_invites is None:
          return 0
      return recent_invites
  
  
  def check_invite_limit(realm: Realm, num_invitees: int) -> None:
      """Discourage using invitation emails as a vector for carrying spam."""
      msg = _(
          "You do not have enough remaining invites for today. "
          "Please contact {email} to have your limit raised. "
          "No invitations were sent."
      ).format(email=settings.ZULIP_ADMINISTRATOR)
      if not settings.OPEN_REALM_CREATION:
          return
  
      recent_invites = estimate_recent_invites([realm], days=1)
      if num_invitees + recent_invites > realm.max_invites:
          raise InvitationError(msg, [], sent_invitations=False)
  
      default_max = settings.INVITES_DEFAULT_REALM_DAILY_MAX
      newrealm_age = datetime.timedelta(days=settings.INVITES_NEW_REALM_DAYS)
      if realm.date_created <= timezone_now() - newrealm_age:
          # If this isn't a "newly-created" realm, we're done. The
          # remaining code applies an aggregate limit across all
          # "new" realms, to address sudden bursts of spam realms.
          return
  
      if realm.max_invites > default_max:
          # If a user is on a realm where we've bumped up
          # max_invites, then we exempt them from invite limits.
          return
  
      new_realms = Realm.objects.filter(
          date_created__gte=timezone_now() - newrealm_age,
          _max_invites__lte=default_max,
      ).all()
  
      for days, count in settings.INVITES_NEW_REALM_LIMIT_DAYS:
          recent_invites = estimate_recent_invites(new_realms, days=days)
          if num_invitees + recent_invites > count:
              raise InvitationError(msg, [], sent_invitations=False)
  
  
  def do_invite_users(
      user_profile: UserProfile,
      invitee_emails: Collection[str],
      streams: Collection[Stream],
      invite_as: int = PreregistrationUser.INVITE_AS["MEMBER"],
  ) -> None:
      num_invites = len(invitee_emails)
  
      check_invite_limit(user_profile.realm, num_invites)
      if settings.BILLING_ENABLED:
          from corporate.lib.registration import check_spare_licenses_available_for_inviting_new_users
  
          check_spare_licenses_available_for_inviting_new_users(user_profile.realm, num_invites)
  
      realm = user_profile.realm
      if not realm.invite_required:
          # Inhibit joining an open realm to send spam invitations.
          min_age = datetime.timedelta(days=settings.INVITES_MIN_USER_AGE_DAYS)
          if user_profile.date_joined > timezone_now() - min_age and not user_profile.is_realm_admin:
              raise InvitationError(
                  _(
                      "Your account is too new to send invites for this organization. "
                      "Ask an organization admin, or a more experienced user."
                  ),
                  [],
                  sent_invitations=False,
              )
  
      good_emails: Set[str] = set()
      errors: List[Tuple[str, str, bool]] = []
      validate_email_allowed_in_realm = get_realm_email_validator(user_profile.realm)
      for email in invitee_emails:
          if email == "":
              continue
          email_error = validate_email_is_valid(
              email,
              validate_email_allowed_in_realm,
          )
  
          if email_error:
              errors.append((email, email_error, False))
          else:
              good_emails.add(email)
  
      """
      good_emails are emails that look ok so far,
      but we still need to make sure they're not
      gonna conflict with existing users
      """
      error_dict = get_existing_user_errors(user_profile.realm, good_emails)
  
      skipped: List[Tuple[str, str, bool]] = []
      for email in error_dict:
          msg, deactivated = error_dict[email]
          skipped.append((email, msg, deactivated))
          good_emails.remove(email)
  
      validated_emails = list(good_emails)
  
      if errors:
          raise InvitationError(
              _("Some emails did not validate, so we didn't send any invitations."),
              errors + skipped,
              sent_invitations=False,
          )
  
      if skipped and len(skipped) == len(invitee_emails):
          # All e-mails were skipped, so we didn't actually invite anyone.
          raise InvitationError(
              _("We weren't able to invite anyone."), skipped, sent_invitations=False
          )
  
      # We do this here rather than in the invite queue processor since this
      # is used for rate limiting invitations, rather than keeping track of
      # when exactly invitations were sent
      do_increment_logging_stat(
          user_profile.realm,
          COUNT_STATS["invites_sent::day"],
          None,
          timezone_now(),
          increment=len(validated_emails),
      )
  
      # Now that we are past all the possible errors, we actually create
      # the PreregistrationUser objects and trigger the email invitations.
      for email in validated_emails:
          # The logged in user is the referrer.
          prereg_user = PreregistrationUser(
              email=email, referred_by=user_profile, invited_as=invite_as, realm=user_profile.realm
          )
          prereg_user.save()
          stream_ids = [stream.id for stream in streams]
          prereg_user.streams.set(stream_ids)
  
          event = {
              "prereg_id": prereg_user.id,
              "referrer_id": user_profile.id,
              "email_language": user_profile.realm.default_language,
          }
          queue_json_publish("invites", event)
  
      if skipped:
          raise InvitationError(
              _(
                  "Some of those addresses are already using Zulip, "
                  "so we didn't send them an invitation. We did send "
                  "invitations to everyone else!"
              ),
              skipped,
              sent_invitations=True,
          )
      notify_invites_changed(user_profile)
  
  
  def do_get_user_invites(user_profile: UserProfile) -> List[Dict[str, Any]]:
      if user_profile.is_realm_admin:
          prereg_users = filter_to_valid_prereg_users(
              PreregistrationUser.objects.filter(referred_by__realm=user_profile.realm)
          )
      else:
          prereg_users = filter_to_valid_prereg_users(
              PreregistrationUser.objects.filter(referred_by=user_profile)
          )
  
      invites = []
  
      for invitee in prereg_users:
          invites.append(
              dict(
                  email=invitee.email,
                  invited_by_user_id=invitee.referred_by.id,
                  invited=datetime_to_timestamp(invitee.invited_at),
                  id=invitee.id,
                  invited_as=invitee.invited_as,
                  is_multiuse=False,
              )
          )
  
      if not user_profile.is_realm_admin:
          # We do not return multiuse invites to non-admin users.
          return invites
  
      lowest_datetime = timezone_now() - datetime.timedelta(
          days=settings.INVITATION_LINK_VALIDITY_DAYS
      )
      multiuse_confirmation_objs = Confirmation.objects.filter(
          realm=user_profile.realm, type=Confirmation.MULTIUSE_INVITE, date_sent__gte=lowest_datetime
      )
      for confirmation_obj in multiuse_confirmation_objs:
          invite = confirmation_obj.content_object
          assert invite is not None
          invites.append(
              dict(
                  invited_by_user_id=invite.referred_by.id,
                  invited=datetime_to_timestamp(confirmation_obj.date_sent),
                  id=invite.id,
                  link_url=confirmation_url(
                      confirmation_obj.confirmation_key,
                      user_profile.realm,
                      Confirmation.MULTIUSE_INVITE,
                  ),
                  invited_as=invite.invited_as,
                  is_multiuse=True,
              )
          )
      return invites
  
  
  def do_create_multiuse_invite_link(
      referred_by: UserProfile, invited_as: int, streams: Sequence[Stream] = []
  ) -> str:
      realm = referred_by.realm
      invite = MultiuseInvite.objects.create(realm=realm, referred_by=referred_by)
      if streams:
          invite.streams.set(streams)
      invite.invited_as = invited_as
      invite.save()
      notify_invites_changed(referred_by)
      return create_confirmation_link(invite, Confirmation.MULTIUSE_INVITE)
  
  
  def do_revoke_user_invite(prereg_user: PreregistrationUser) -> None:
      email = prereg_user.email
  
      # Delete both the confirmation objects and the prereg_user object.
      # TODO: Probably we actually want to set the confirmation objects
      # to a "revoked" status so that we can give the invited user a better
      # error message.
      content_type = ContentType.objects.get_for_model(PreregistrationUser)
      Confirmation.objects.filter(content_type=content_type, object_id=prereg_user.id).delete()
      prereg_user.delete()
      clear_scheduled_invitation_emails(email)
      notify_invites_changed(prereg_user)
  
  
  def do_revoke_multi_use_invite(multiuse_invite: MultiuseInvite) -> None:
      content_type = ContentType.objects.get_for_model(MultiuseInvite)
      Confirmation.objects.filter(content_type=content_type, object_id=multiuse_invite.id).delete()
      multiuse_invite.delete()
      notify_invites_changed(multiuse_invite.referred_by)
  
  
  def do_resend_user_invite_email(prereg_user: PreregistrationUser) -> int:
      # These are two structurally for the caller's code path.
      assert prereg_user.referred_by is not None
      assert prereg_user.realm is not None
  
      check_invite_limit(prereg_user.referred_by.realm, 1)
  
      prereg_user.invited_at = timezone_now()
      prereg_user.save()
  
      do_increment_logging_stat(
          prereg_user.realm, COUNT_STATS["invites_sent::day"], None, prereg_user.invited_at
      )
  
      clear_scheduled_invitation_emails(prereg_user.email)
      # We don't store the custom email body, so just set it to None
      event = {
          "prereg_id": prereg_user.id,
          "referrer_id": prereg_user.referred_by.id,
          "email_language": prereg_user.referred_by.realm.default_language,
      }
      queue_json_publish("invites", event)
  
      return datetime_to_timestamp(prereg_user.invited_at)
  
  
  def notify_realm_emoji(realm: Realm) -> None:
      event = dict(type="realm_emoji", op="update", realm_emoji=realm.get_emoji())
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def check_add_realm_emoji(
      realm: Realm, name: str, author: UserProfile, image_file: IO[bytes]
  ) -> Optional[RealmEmoji]:
      realm_emoji = RealmEmoji(realm=realm, name=name, author=author)
      realm_emoji.full_clean()
      realm_emoji.save()
  
      emoji_file_name = get_emoji_file_name(image_file.name, realm_emoji.id)
  
      # The only user-controlled portion of 'emoji_file_name' is an extension,
      # which can not contain '..' or '/' or '\', making it difficult to exploit
      emoji_file_name = mark_sanitized(emoji_file_name)
  
      emoji_uploaded_successfully = False
      try:
          upload_emoji_image(image_file, emoji_file_name, author)
          emoji_uploaded_successfully = True
      finally:
          if not emoji_uploaded_successfully:
              realm_emoji.delete()
              return None
          else:
              realm_emoji.file_name = emoji_file_name
              realm_emoji.save(update_fields=["file_name"])
              notify_realm_emoji(realm_emoji.realm)
      return realm_emoji
  
  
  def do_remove_realm_emoji(realm: Realm, name: str) -> None:
      emoji = RealmEmoji.objects.get(realm=realm, name=name, deactivated=False)
      emoji.deactivated = True
      emoji.save(update_fields=["deactivated"])
      notify_realm_emoji(realm)
  
  
  def notify_alert_words(user_profile: UserProfile, words: Sequence[str]) -> None:
      event = dict(type="alert_words", alert_words=words)
      send_event(user_profile.realm, event, [user_profile.id])
  
  
  def do_add_alert_words(user_profile: UserProfile, alert_words: Iterable[str]) -> None:
      words = add_user_alert_words(user_profile, alert_words)
      notify_alert_words(user_profile, words)
  
  
  def do_remove_alert_words(user_profile: UserProfile, alert_words: Iterable[str]) -> None:
      words = remove_user_alert_words(user_profile, alert_words)
      notify_alert_words(user_profile, words)
  
  
  def do_mute_topic(
      user_profile: UserProfile,
      stream: Stream,
      topic: str,
      date_muted: Optional[datetime.datetime] = None,
  ) -> None:
      if date_muted is None:
          date_muted = timezone_now()
      add_topic_mute(user_profile, stream.id, stream.recipient_id, topic, date_muted)
      event = dict(type="muted_topics", muted_topics=get_topic_mutes(user_profile))
      send_event(user_profile.realm, event, [user_profile.id])
  
  
  def do_unmute_topic(user_profile: UserProfile, stream: Stream, topic: str) -> None:
      remove_topic_mute(user_profile, stream.id, topic)
      event = dict(type="muted_topics", muted_topics=get_topic_mutes(user_profile))
      send_event(user_profile.realm, event, [user_profile.id])
  
  
  def do_mute_user(
      user_profile: UserProfile,
      muted_user: UserProfile,
      date_muted: Optional[datetime.datetime] = None,
  ) -> None:
      if date_muted is None:
          date_muted = timezone_now()
      add_user_mute(user_profile, muted_user, date_muted)
      do_mark_muted_user_messages_as_read(user_profile, muted_user)
      event = dict(type="muted_users", muted_users=get_user_mutes(user_profile))
      send_event(user_profile.realm, event, [user_profile.id])
  
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=user_profile,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_MUTED,
          event_time=date_muted,
          extra_data=orjson.dumps({"muted_user_id": muted_user.id}).decode(),
      )
  
  
  def do_unmute_user(mute_object: MutedUser) -> None:
      user_profile = mute_object.user_profile
      muted_user = mute_object.muted_user
      mute_object.delete()
      event = dict(type="muted_users", muted_users=get_user_mutes(user_profile))
      send_event(user_profile.realm, event, [user_profile.id])
  
      RealmAuditLog.objects.create(
          realm=user_profile.realm,
          acting_user=user_profile,
          modified_user=user_profile,
          event_type=RealmAuditLog.USER_UNMUTED,
          event_time=timezone_now(),
          extra_data=orjson.dumps({"unmuted_user_id": muted_user.id}).decode(),
      )
  
  
  def do_mark_hotspot_as_read(user: UserProfile, hotspot: str) -> None:
      UserHotspot.objects.get_or_create(user=user, hotspot=hotspot)
      event = dict(type="hotspots", hotspots=get_next_hotspots(user))
      send_event(user.realm, event, [user.id])
  
  
  def notify_linkifiers(realm: Realm) -> None:
      realm_linkifiers = linkifiers_for_realm(realm.id)
      event = dict(type="realm_linkifiers", realm_linkifiers=realm_linkifiers)
      send_event(realm, event, active_user_ids(realm.id))
  
      # Below is code for backwards compatibility. The now deprecated
      # "realm_filters" event-type is used by older clients, and uses
      # tuples.
      realm_filters = realm_filters_for_realm(realm.id)
      event = dict(type="realm_filters", realm_filters=realm_filters)
      send_event(realm, event, active_user_ids(realm.id))
  
  
  # NOTE: Regexes must be simple enough that they can be easily translated to JavaScript
  # RegExp syntax. In addition to JS-compatible syntax, the following features are available:
  #   * Named groups will be converted to numbered groups automatically
  #   * Inline-regex flags will be stripped, and where possible translated to RegExp-wide flags
  def do_add_linkifier(realm: Realm, pattern: str, url_format_string: str) -> int:
      pattern = pattern.strip()
      url_format_string = url_format_string.strip()
      linkifier = RealmFilter(realm=realm, pattern=pattern, url_format_string=url_format_string)
      linkifier.full_clean()
      linkifier.save()
      notify_linkifiers(realm)
  
      return linkifier.id
  
  
  def do_remove_linkifier(
      realm: Realm, pattern: Optional[str] = None, id: Optional[int] = None
  ) -> None:
      if pattern is not None:
          RealmFilter.objects.get(realm=realm, pattern=pattern).delete()
      else:
          RealmFilter.objects.get(realm=realm, id=id).delete()
      notify_linkifiers(realm)
  
  
  def do_update_linkifier(realm: Realm, id: int, pattern: str, url_format_string: str) -> None:
      pattern = pattern.strip()
      url_format_string = url_format_string.strip()
      linkifier = RealmFilter.objects.get(realm=realm, id=id)
      linkifier.pattern = pattern
      linkifier.url_format_string = url_format_string
      linkifier.full_clean()
      linkifier.save(update_fields=["pattern", "url_format_string"])
      notify_linkifiers(realm)
  
  
  def do_add_realm_domain(realm: Realm, domain: str, allow_subdomains: bool) -> (RealmDomain):
      realm_domain = RealmDomain.objects.create(
          realm=realm, domain=domain, allow_subdomains=allow_subdomains
      )
      event = dict(
          type="realm_domains",
          op="add",
          realm_domain=dict(
              domain=realm_domain.domain, allow_subdomains=realm_domain.allow_subdomains
          ),
      )
      send_event(realm, event, active_user_ids(realm.id))
      return realm_domain
  
  
  def do_change_realm_domain(realm_domain: RealmDomain, allow_subdomains: bool) -> None:
      realm_domain.allow_subdomains = allow_subdomains
      realm_domain.save(update_fields=["allow_subdomains"])
      event = dict(
          type="realm_domains",
          op="change",
          realm_domain=dict(
              domain=realm_domain.domain, allow_subdomains=realm_domain.allow_subdomains
          ),
      )
      send_event(realm_domain.realm, event, active_user_ids(realm_domain.realm_id))
  
  
  def do_remove_realm_domain(
      realm_domain: RealmDomain, *, acting_user: Optional[UserProfile]
  ) -> None:
      realm = realm_domain.realm
      domain = realm_domain.domain
      realm_domain.delete()
      if RealmDomain.objects.filter(realm=realm).count() == 0 and realm.emails_restricted_to_domains:
          # If this was the last realm domain, we mark the realm as no
          # longer restricted to domain, because the feature doesn't do
          # anything if there are no domains, and this is probably less
          # confusing than the alternative.
          do_set_realm_property(realm, "emails_restricted_to_domains", False, acting_user=acting_user)
      event = dict(type="realm_domains", op="remove", domain=domain)
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def notify_realm_playgrounds(realm: Realm) -> None:
      event = dict(type="realm_playgrounds", realm_playgrounds=get_realm_playgrounds(realm))
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def do_add_realm_playground(realm: Realm, **kwargs: Any) -> int:
      realm_playground = RealmPlayground(realm=realm, **kwargs)
      # We expect full_clean to always pass since a thorough input validation
      # is performed in the view (using check_url, check_pygments_language, etc)
      # before calling this function.
      realm_playground.full_clean()
      realm_playground.save()
      notify_realm_playgrounds(realm)
      return realm_playground.id
  
  
  def do_remove_realm_playground(realm: Realm, realm_playground: RealmPlayground) -> None:
      realm_playground.delete()
      notify_realm_playgrounds(realm)
  
  
  def get_occupied_streams(realm: Realm) -> QuerySet:
      # TODO: Make a generic stub for QuerySet
      """Get streams with subscribers"""
      exists_expression = Exists(
          Subscription.objects.filter(
              active=True,
              is_user_active=True,
              user_profile__realm=realm,
              recipient_id=OuterRef("recipient_id"),
          ),
      )
      occupied_streams = (
          Stream.objects.filter(realm=realm, deactivated=False)
          .annotate(occupied=exists_expression)
          .filter(occupied=True)
      )
      return occupied_streams
  
  
  def get_web_public_streams(realm: Realm) -> List[Dict[str, Any]]:  # nocoverage
      query = Stream.objects.filter(realm=realm, deactivated=False, is_web_public=True)
      streams = Stream.get_client_data(query)
      return streams
  
  
  def do_get_streams(
      user_profile: UserProfile,
      include_public: bool = True,
      include_web_public: bool = False,
      include_subscribed: bool = True,
      include_all_active: bool = False,
      include_default: bool = False,
      include_owner_subscribed: bool = False,
  ) -> List[Dict[str, Any]]:
      # This function is only used by API clients now.
  
      if include_all_active and not user_profile.is_realm_admin:
          raise JsonableError(_("User not authorized for this query"))
  
      include_public = include_public and user_profile.can_access_public_streams()
  
      # Start out with all active streams in the realm.
      query = Stream.objects.filter(realm=user_profile.realm, deactivated=False)
  
      if include_all_active:
          streams = Stream.get_client_data(query)
      else:
          # We construct a query as the or (|) of the various sources
          # this user requested streams from.
          query_filter: Optional[Q] = None
  
          def add_filter_option(option: Q) -> None:
              nonlocal query_filter
              if query_filter is None:
                  query_filter = option
              else:
                  query_filter |= option
  
          if include_subscribed:
              subscribed_stream_ids = get_subscribed_stream_ids_for_user(user_profile)
              recipient_check = Q(id__in=set(subscribed_stream_ids))
              add_filter_option(recipient_check)
          if include_public:
              invite_only_check = Q(invite_only=False)
              add_filter_option(invite_only_check)
          if include_web_public:
              web_public_check = Q(is_web_public=True)
              add_filter_option(web_public_check)
          if include_owner_subscribed and user_profile.is_bot:
              bot_owner = user_profile.bot_owner
              assert bot_owner is not None
              owner_stream_ids = get_subscribed_stream_ids_for_user(bot_owner)
              owner_subscribed_check = Q(id__in=set(owner_stream_ids))
              add_filter_option(owner_subscribed_check)
  
          if query_filter is not None:
              query = query.filter(query_filter)
              streams = Stream.get_client_data(query)
          else:
              # Don't bother going to the database with no valid sources
              streams = []
  
      streams.sort(key=lambda elt: elt["name"])
  
      if include_default:
          is_default = {}
          default_streams = get_default_streams_for_realm(user_profile.realm_id)
          for default_stream in default_streams:
              is_default[default_stream.id] = True
          for stream in streams:
              stream["is_default"] = is_default.get(stream["stream_id"], False)
  
      return streams
  
  
  def notify_attachment_update(
      user_profile: UserProfile, op: str, attachment_dict: Dict[str, Any]
  ) -> None:
      event = {
          "type": "attachment",
          "op": op,
          "attachment": attachment_dict,
          "upload_space_used": user_profile.realm.currently_used_upload_space_bytes(),
      }
      send_event(user_profile.realm, event, [user_profile.id])
  
  
  def do_claim_attachments(message: Message, potential_path_ids: List[str]) -> bool:
      claimed = False
      for path_id in potential_path_ids:
          user_profile = message.sender
          is_message_realm_public = False
          is_message_web_public = False
          if message.is_stream_message():
              stream = Stream.objects.get(id=message.recipient.type_id)
              is_message_realm_public = stream.is_public()
              is_message_web_public = stream.is_web_public
  
          if not validate_attachment_request(user_profile, path_id):
              # Technically, there are 2 cases here:
              # * The user put something in their message that has the form
              # of an upload, but doesn't correspond to a file that doesn't
              # exist.  validate_attachment_request will return None.
              # * The user is trying to send a link to a file they don't have permission to
              # access themselves.  validate_attachment_request will return False.
              #
              # Either case is unusual and suggests a UI bug that got
              # the user in this situation, so we log in these cases.
              logging.warning(
                  "User %s tried to share upload %s in message %s, but lacks permission",
                  user_profile.id,
                  path_id,
                  message.id,
              )
              continue
  
          claimed = True
          attachment = claim_attachment(
              user_profile, path_id, message, is_message_realm_public, is_message_web_public
          )
          notify_attachment_update(user_profile, "update", attachment.to_dict())
      return claimed
  
  
  def do_delete_old_unclaimed_attachments(weeks_ago: int) -> None:
      old_unclaimed_attachments = get_old_unclaimed_attachments(weeks_ago)
  
      for attachment in old_unclaimed_attachments:
          delete_message_image(attachment.path_id)
          attachment.delete()
  
  
  def check_attachment_reference_change(
      message: Message, rendering_result: MessageRenderingResult
  ) -> bool:
      # For a unsaved message edit (message.* has been updated, but not
      # saved to the database), adjusts Attachment data to correspond to
      # the new content.
      prev_attachments = {a.path_id for a in message.attachment_set.all()}
      new_attachments = set(rendering_result.potential_attachment_path_ids)
  
      if new_attachments == prev_attachments:
          return bool(prev_attachments)
  
      to_remove = list(prev_attachments - new_attachments)
      if len(to_remove) > 0:
          attachments_to_update = Attachment.objects.filter(path_id__in=to_remove).select_for_update()
          message.attachment_set.remove(*attachments_to_update)
  
      to_add = list(new_attachments - prev_attachments)
      if len(to_add) > 0:
          do_claim_attachments(message, to_add)
  
      return message.attachment_set.exists()
  
  
  def notify_realm_custom_profile_fields(realm: Realm) -> None:
      fields = custom_profile_fields_for_realm(realm.id)
      event = dict(type="custom_profile_fields", fields=[f.as_dict() for f in fields])
      send_event(realm, event, active_user_ids(realm.id))
  
  
  def try_add_realm_default_custom_profile_field(
      realm: Realm, field_subtype: str
  ) -> CustomProfileField:
      field_data = DEFAULT_EXTERNAL_ACCOUNTS[field_subtype]
      custom_profile_field = CustomProfileField(
          realm=realm,
          name=field_data["name"],
          field_type=CustomProfileField.EXTERNAL_ACCOUNT,
          hint=field_data["hint"],
          field_data=orjson.dumps(dict(subtype=field_subtype)).decode(),
      )
      custom_profile_field.save()
      custom_profile_field.order = custom_profile_field.id
      custom_profile_field.save(update_fields=["order"])
      notify_realm_custom_profile_fields(realm)
      return custom_profile_field
  
  
  def try_add_realm_custom_profile_field(
      realm: Realm,
      name: str,
      field_type: int,
      hint: str = "",
      field_data: Optional[ProfileFieldData] = None,
  ) -> CustomProfileField:
      custom_profile_field = CustomProfileField(realm=realm, name=name, field_type=field_type)
      custom_profile_field.hint = hint
      if (
          custom_profile_field.field_type == CustomProfileField.SELECT
          or custom_profile_field.field_type == CustomProfileField.EXTERNAL_ACCOUNT
      ):
          custom_profile_field.field_data = orjson.dumps(field_data or {}).decode()
  
      custom_profile_field.save()
      custom_profile_field.order = custom_profile_field.id
      custom_profile_field.save(update_fields=["order"])
      notify_realm_custom_profile_fields(realm)
      return custom_profile_field
  
  
  def do_remove_realm_custom_profile_field(realm: Realm, field: CustomProfileField) -> None:
      """
      Deleting a field will also delete the user profile data
      associated with it in CustomProfileFieldValue model.
      """
      field.delete()
      notify_realm_custom_profile_fields(realm)
  
  
  def do_remove_realm_custom_profile_fields(realm: Realm) -> None:
      CustomProfileField.objects.filter(realm=realm).delete()
  
  
  def try_update_realm_custom_profile_field(
      realm: Realm,
      field: CustomProfileField,
      name: str,
      hint: str = "",
      field_data: Optional[ProfileFieldData] = None,
  ) -> None:
      field.name = name
      field.hint = hint
      if (
          field.field_type == CustomProfileField.SELECT
          or field.field_type == CustomProfileField.EXTERNAL_ACCOUNT
      ):
          field.field_data = orjson.dumps(field_data or {}).decode()
      field.save()
      notify_realm_custom_profile_fields(realm)
  
  
  def try_reorder_realm_custom_profile_fields(realm: Realm, order: List[int]) -> None:
      order_mapping = {_[1]: _[0] for _ in enumerate(order)}
      custom_profile_fields = CustomProfileField.objects.filter(realm=realm)
      for custom_profile_field in custom_profile_fields:
          if custom_profile_field.id not in order_mapping:
              raise JsonableError(_("Invalid order mapping."))
      for custom_profile_field in custom_profile_fields:
          custom_profile_field.order = order_mapping[custom_profile_field.id]
          custom_profile_field.save(update_fields=["order"])
      notify_realm_custom_profile_fields(realm)
  
  
  def notify_user_update_custom_profile_data(
      user_profile: UserProfile, field: Dict[str, Union[int, str, List[int], None]]
  ) -> None:
      data = dict(id=field["id"])
      if field["type"] == CustomProfileField.USER:
          data["value"] = orjson.dumps(field["value"]).decode()
      else:
          data["value"] = field["value"]
      if field["rendered_value"]:
          data["rendered_value"] = field["rendered_value"]
      payload = dict(user_id=user_profile.id, custom_profile_field=data)
      event = dict(type="realm_user", op="update", person=payload)
      send_event(user_profile.realm, event, active_user_ids(user_profile.realm.id))
  
  
  def do_update_user_custom_profile_data_if_changed(
      user_profile: UserProfile,
      data: List[Dict[str, Union[int, str, List[int]]]],
  ) -> None:
      with transaction.atomic():
          for custom_profile_field in data:
              field_value, created = CustomProfileFieldValue.objects.get_or_create(
                  user_profile=user_profile, field_id=custom_profile_field["id"]
              )
  
              if not created and field_value.value == str(custom_profile_field["value"]):
                  # If the field value isn't actually being changed to a different one,
                  # we have nothing to do here for this field.
                  # Note: field_value.value is a TextField() so we need to cast field['value']
                  # to a string for the comparison in this if.
                  continue
  
              field_value.value = custom_profile_field["value"]
              if field_value.field.is_renderable():
                  field_value.rendered_value = render_stream_description(
                      str(custom_profile_field["value"])
                  )
                  field_value.save(update_fields=["value", "rendered_value"])
              else:
                  field_value.save(update_fields=["value"])
              notify_user_update_custom_profile_data(
                  user_profile,
                  {
                      "id": field_value.field_id,
                      "value": field_value.value,
                      "rendered_value": field_value.rendered_value,
                      "type": field_value.field.field_type,
                  },
              )
  
  
  def check_remove_custom_profile_field_value(user_profile: UserProfile, field_id: int) -> None:
      try:
          custom_profile_field = CustomProfileField.objects.get(realm=user_profile.realm, id=field_id)
          field_value = CustomProfileFieldValue.objects.get(
              field=custom_profile_field, user_profile=user_profile
          )
          field_value.delete()
          notify_user_update_custom_profile_data(
              user_profile,
              {
                  "id": field_id,
                  "value": None,
                  "rendered_value": None,
                  "type": custom_profile_field.field_type,
              },
          )
      except CustomProfileField.DoesNotExist:
          raise JsonableError(_("Field id {id} not found.").format(id=field_id))
      except CustomProfileFieldValue.DoesNotExist:
          pass
  
  
  def do_send_create_user_group_event(user_group: UserGroup, members: List[UserProfile]) -> None:
      event = dict(
          type="user_group",
          op="add",
          group=dict(
              name=user_group.name,
              members=[member.id for member in members],
              description=user_group.description,
              id=user_group.id,
              is_system_group=user_group.is_system_group,
          ),
      )
      send_event(user_group.realm, event, active_user_ids(user_group.realm_id))
  
  
  def check_add_user_group(
      realm: Realm, name: str, initial_members: List[UserProfile], description: str
  ) -> None:
      try:
          user_group = create_user_group(name, initial_members, realm, description=description)
          do_send_create_user_group_event(user_group, initial_members)
      except django.db.utils.IntegrityError:
          raise JsonableError(_("User group '{}' already exists.").format(name))
  
  
  def do_send_user_group_update_event(user_group: UserGroup, data: Dict[str, str]) -> None:
      event = dict(type="user_group", op="update", group_id=user_group.id, data=data)
      send_event(user_group.realm, event, active_user_ids(user_group.realm_id))
  
  
  def do_update_user_group_name(user_group: UserGroup, name: str) -> None:
      try:
          user_group.name = name
          user_group.save(update_fields=["name"])
      except django.db.utils.IntegrityError:
          raise JsonableError(_("User group '{}' already exists.").format(name))
      do_send_user_group_update_event(user_group, dict(name=name))
  
  
  def do_update_user_group_description(user_group: UserGroup, description: str) -> None:
      user_group.description = description
      user_group.save(update_fields=["description"])
      do_send_user_group_update_event(user_group, dict(description=description))
  
  
  def do_update_outgoing_webhook_service(
      bot_profile: UserProfile, service_interface: int, service_payload_url: str
  ) -> None:
      # TODO: First service is chosen because currently one bot can only have one service.
      # Update this once multiple services are supported.
      service = get_bot_services(bot_profile.id)[0]
      service.base_url = service_payload_url
      service.interface = service_interface
      service.save()
      send_event(
          bot_profile.realm,
          dict(
              type="realm_bot",
              op="update",
              bot=dict(
                  user_id=bot_profile.id,
                  services=[
                      dict(
                          base_url=service.base_url, interface=service.interface, token=service.token
                      )
                  ],
              ),
          ),
          bot_owner_user_ids(bot_profile),
      )
  
  
  def do_update_bot_config_data(bot_profile: UserProfile, config_data: Dict[str, str]) -> None:
      for key, value in config_data.items():
          set_bot_config(bot_profile, key, value)
      updated_config_data = get_bot_config(bot_profile)
      send_event(
          bot_profile.realm,
          dict(
              type="realm_bot",
              op="update",
              bot=dict(
                  user_id=bot_profile.id,
                  services=[dict(config_data=updated_config_data)],
              ),
          ),
          bot_owner_user_ids(bot_profile),
      )
  
  
  def get_service_dicts_for_bot(user_profile_id: int) -> List[Dict[str, Any]]:
      user_profile = get_user_profile_by_id(user_profile_id)
      services = get_bot_services(user_profile_id)
      service_dicts: List[Dict[str, Any]] = []
      if user_profile.bot_type == UserProfile.OUTGOING_WEBHOOK_BOT:
          service_dicts = [
              {
                  "base_url": service.base_url,
                  "interface": service.interface,
                  "token": service.token,
              }
              for service in services
          ]
      elif user_profile.bot_type == UserProfile.EMBEDDED_BOT:
          try:
              service_dicts = [
                  {
                      "config_data": get_bot_config(user_profile),
                      "service_name": services[0].name,
                  }
              ]
          # A ConfigError just means that there are no config entries for user_profile.
          except ConfigError:
              pass
      return service_dicts
  
  
  def get_service_dicts_for_bots(
      bot_dicts: List[Dict[str, Any]], realm: Realm
  ) -> Dict[int, List[Dict[str, Any]]]:
      bot_profile_ids = [bot_dict["id"] for bot_dict in bot_dicts]
      bot_services_by_uid: Dict[int, List[Service]] = defaultdict(list)
      for service in Service.objects.filter(user_profile_id__in=bot_profile_ids):
          bot_services_by_uid[service.user_profile_id].append(service)
  
      embedded_bot_ids = [
          bot_dict["id"] for bot_dict in bot_dicts if bot_dict["bot_type"] == UserProfile.EMBEDDED_BOT
      ]
      embedded_bot_configs = get_bot_configs(embedded_bot_ids)
  
      service_dicts_by_uid: Dict[int, List[Dict[str, Any]]] = {}
      for bot_dict in bot_dicts:
          bot_profile_id = bot_dict["id"]
          bot_type = bot_dict["bot_type"]
          services = bot_services_by_uid[bot_profile_id]
          service_dicts: List[Dict[str, Any]] = []
          if bot_type == UserProfile.OUTGOING_WEBHOOK_BOT:
              service_dicts = [
                  {
                      "base_url": service.base_url,
                      "interface": service.interface,
                      "token": service.token,
                  }
                  for service in services
              ]
          elif bot_type == UserProfile.EMBEDDED_BOT:
              if bot_profile_id in embedded_bot_configs.keys():
                  bot_config = embedded_bot_configs[bot_profile_id]
                  service_dicts = [
                      {
                          "config_data": bot_config,
                          "service_name": services[0].name,
                      }
                  ]
          service_dicts_by_uid[bot_profile_id] = service_dicts
      return service_dicts_by_uid
  
  
  def get_owned_bot_dicts(
      user_profile: UserProfile, include_all_realm_bots_if_admin: bool = True
  ) -> List[Dict[str, Any]]:
      if user_profile.is_realm_admin and include_all_realm_bots_if_admin:
          result = get_bot_dicts_in_realm(user_profile.realm)
      else:
          result = UserProfile.objects.filter(
              realm=user_profile.realm, is_bot=True, bot_owner=user_profile
          ).values(*bot_dict_fields)
      services_by_ids = get_service_dicts_for_bots(result, user_profile.realm)
      return [
          {
              "email": botdict["email"],
              "user_id": botdict["id"],
              "full_name": botdict["full_name"],
              "bot_type": botdict["bot_type"],
              "is_active": botdict["is_active"],
              "api_key": botdict["api_key"],
              "default_sending_stream": botdict["default_sending_stream__name"],
              "default_events_register_stream": botdict["default_events_register_stream__name"],
              "default_all_public_streams": botdict["default_all_public_streams"],
              "owner_id": botdict["bot_owner_id"],
              "avatar_url": avatar_url_from_dict(botdict),
              "services": services_by_ids[botdict["id"]],
          }
          for botdict in result
      ]
  
  
  def do_send_user_group_members_update_event(
      event_name: str, user_group: UserGroup, user_ids: List[int]
  ) -> None:
      event = dict(type="user_group", op=event_name, group_id=user_group.id, user_ids=user_ids)
      send_event(user_group.realm, event, active_user_ids(user_group.realm_id))
  
  
  def bulk_add_members_to_user_group(user_group: UserGroup, user_profiles: List[UserProfile]) -> None:
      memberships = [
          UserGroupMembership(user_group_id=user_group.id, user_profile=user_profile)
          for user_profile in user_profiles
      ]
      UserGroupMembership.objects.bulk_create(memberships)
  
      user_ids = [up.id for up in user_profiles]
      do_send_user_group_members_update_event("add_members", user_group, user_ids)
  
  
  def remove_members_from_user_group(user_group: UserGroup, user_profiles: List[UserProfile]) -> None:
      UserGroupMembership.objects.filter(
          user_group_id=user_group.id, user_profile__in=user_profiles
      ).delete()
  
      user_ids = [up.id for up in user_profiles]
      do_send_user_group_members_update_event("remove_members", user_group, user_ids)
  
  
  def do_send_delete_user_group_event(realm: Realm, user_group_id: int, realm_id: int) -> None:
      event = dict(type="user_group", op="remove", group_id=user_group_id)
      send_event(realm, event, active_user_ids(realm_id))
  
  
  def check_delete_user_group(user_group_id: int, user_profile: UserProfile) -> None:
      user_group = access_user_group_by_id(user_group_id, user_profile)
      user_group.delete()
      do_send_delete_user_group_event(user_profile.realm, user_group_id, user_profile.realm.id)
  
  
  def do_send_realm_reactivation_email(realm: Realm, *, acting_user: Optional[UserProfile]) -> None:
      url = create_confirmation_link(realm, Confirmation.REALM_REACTIVATION)
      RealmAuditLog.objects.create(
          realm=realm,
          acting_user=acting_user,
          event_type=RealmAuditLog.REALM_REACTIVATION_EMAIL_SENT,
          event_time=timezone_now(),
      )
      context = {"confirmation_url": url, "realm_uri": realm.uri, "realm_name": realm.name}
      language = realm.default_language
      send_email_to_admins(
          "zerver/emails/realm_reactivation",
          realm,
          from_address=FromAddress.tokenized_no_reply_address(),
          from_name=FromAddress.security_email_from_name(language=language),
          language=language,
          context=context,
      )
  
  
  def do_set_zoom_token(user: UserProfile, token: Optional[Dict[str, object]]) -> None:
      user.zoom_token = token
      user.save(update_fields=["zoom_token"])
      send_event(
          user.realm,
          dict(type="has_zoom_token", value=token is not None),
          [user.id],
      )
  
  
  def notify_realm_export(user_profile: UserProfile) -> None:
      # In the future, we may want to send this event to all realm admins.
      event = dict(type="realm_export", exports=get_realm_exports_serialized(user_profile))
      send_event(user_profile.realm, event, [user_profile.id])
  
  
  def do_delete_realm_export(user_profile: UserProfile, export: RealmAuditLog) -> None:
      # Give mypy a hint so it knows `orjson.loads`
      # isn't being passed an `Optional[str]`.
      export_extra_data = export.extra_data
      assert export_extra_data is not None
      export_data = orjson.loads(export_extra_data)
      export_path = export_data.get("export_path")
  
      if export_path:
          # Allow removal even if the export failed.
          delete_export_tarball(export_path)
  
      export_data.update(deleted_timestamp=timezone_now().timestamp())
      export.extra_data = orjson.dumps(export_data).decode()
      export.save(update_fields=["extra_data"])
      notify_realm_export(user_profile)
  
  
  def get_topic_messages(user_profile: UserProfile, stream: Stream, topic_name: str) -> List[Message]:
      query = UserMessage.objects.filter(
          user_profile=user_profile,
          message__recipient=stream.recipient,
      ).order_by("id")
      return [um.message for um in filter_by_topic_name_via_message(query, topic_name)]
  