text: # -*- coding: utf-8 -*-
  import hashlib
  from typing import Text
  
  from django.conf import settings
  from django.db import migrations
  from django.db.backends.postgresql_psycopg2.schema import DatabaseSchemaEditor
  from django.db.migrations.state import StateApps
  from mock import patch
  
  from zerver.lib.upload import upload_backend
  from zerver.lib.utils import make_safe_digest
  from zerver.models import UserProfile
  
  
  # We hackishly patch this function in order to revert it to the state
  # it had when this migration was first written.  This is a balance
  # between copying in a historical version of hundreds of lines of code
  # from zerver.lib.upload (which would pretty annoying, but would be a
  # pain) and just using the current version, which doesn't work
  # since we rearranged the avatars in Zulip 1.6.
  def patched_user_avatar_path(user_profile: UserProfile) -> Text:
      email = user_profile.email
      user_key = email.lower() + settings.AVATAR_SALT
      return make_safe_digest(user_key, hashlib.sha1)
  
  @patch('zerver.lib.upload.user_avatar_path', patched_user_avatar_path)
  def verify_medium_avatar_image(apps: StateApps, schema_editor: DatabaseSchemaEditor) -> None:
      user_profile_model = apps.get_model('zerver', 'UserProfile')
      for user_profile in user_profile_model.objects.filter(avatar_source="U"):
          upload_backend.ensure_medium_avatar_image(user_profile)
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('zerver', '0031_remove_system_avatar_source'),
      ]
  
      operations = [
          migrations.RunPython(verify_medium_avatar_image)
      ]
  