text: # -*- coding: utf-8 -*-
  
  """
  The MIT License (MIT)
  
  Copyright (c) 2015-2016 Rapptz
  
  Permission is hereby granted, free of charge, to any person obtaining a
  copy of this software and associated documentation files (the "Software"),
  to deal in the Software without restriction, including without limitation
  the rights to use, copy, modify, merge, publish, distribute, sublicense,
  and/or sell copies of the Software, and to permit persons to whom the
  Software is furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  DEALINGS IN THE SOFTWARE.
  """
  
  import sys
  import websockets
  import asyncio
  import aiohttp
  from . import utils, compat
  from .enums import Status, try_enum
  from .game import Game
  from .errors import GatewayNotFound, ConnectionClosed, InvalidArgument
  import logging
  import zlib, time, json
  from collections import namedtuple
  import threading
  import struct
  
  log = logging.getLogger(__name__)
  
  __all__ = [ 'ReconnectWebSocket', 'DiscordWebSocket',
              'KeepAliveHandler', 'VoiceKeepAliveHandler',
              'DiscordVoiceWebSocket', 'ResumeWebSocket' ]
  
  class ReconnectWebSocket(Exception):
      """Signals to handle the RECONNECT opcode."""
      pass
  
  class ResumeWebSocket(Exception):
      """Signals to initialise via RESUME opcode instead of IDENTIFY."""
      pass
  
  EventListener = namedtuple('EventListener', 'predicate event result future')
  
  class KeepAliveHandler(threading.Thread):
      def __init__(self, *args, **kwargs):
          ws = kwargs.pop('ws', None)
          interval = kwargs.pop('interval', None)
          threading.Thread.__init__(self, *args, **kwargs)
          self.ws = ws
          self.interval = interval
          self.daemon = True
          self.msg = 'Keeping websocket alive with sequence {0[d]}'
          self._stop_ev = threading.Event()
  
      def run(self):
          while not self._stop_ev.wait(self.interval):
              data = self.get_payload()
              log.debug(self.msg.format(data))
              coro = self.ws.send_as_json(data)
              f = compat.run_coroutine_threadsafe(coro, loop=self.ws.loop)
              try:
                  # block until sending is complete
                  f.result()
              except Exception:
                  self.stop()
  
      def get_payload(self):
          return {
              'op': self.ws.HEARTBEAT,
              'd': self.ws._connection.sequence
          }
  
      def stop(self):
          self._stop_ev.set()
  
  class VoiceKeepAliveHandler(KeepAliveHandler):
      def __init__(self, *args, **kwargs):
          super().__init__(*args, **kwargs)
          self.msg = 'Keeping voice websocket alive with timestamp {0[d]}'
  
      def get_payload(self):
          return {
              'op': self.ws.HEARTBEAT,
              'd': int(time.time() * 1000)
          }
  
  class DiscordWebSocket(websockets.client.WebSocketClientProtocol):
      """Implements a WebSocket for Discord's gateway v6.
  
      This is created through :func:`create_main_websocket`. Library
      users should never create this manually.
  
      Attributes
      -----------
      DISPATCH
          Receive only. Denotes an event to be sent to Discord, such as READY.
      HEARTBEAT
          When received tells Discord to keep the connection alive.
          When sent asks if your connection is currently alive.
      IDENTIFY
          Send only. Starts a new session.
      PRESENCE
          Send only. Updates your presence.
      VOICE_STATE
          Send only. Starts a new connection to a voice server.
      VOICE_PING
          Send only. Checks ping time to a voice server, do not use.
      RESUME
          Send only. Resumes an existing connection.
      RECONNECT
          Receive only. Tells the client to reconnect to a new gateway.
      REQUEST_MEMBERS
          Send only. Asks for the full member list of a server.
      INVALIDATE_SESSION
          Receive only. Tells the client to invalidate the session and IDENTIFY
          again.
      HELLO
          Receive only. Tells the client the heartbeat interval.
      HEARTBEAT_ACK
          Receive only. Confirms receiving of a heartbeat. Not having it implies
          a connection issue.
      GUILD_SYNC
          Send only. Requests a guild sync.
      gateway
          The gateway we are currently connected to.
      token
          The authentication token for discord.
      """
  
      DISPATCH           = 0
      HEARTBEAT          = 1
      IDENTIFY           = 2
      PRESENCE           = 3
      VOICE_STATE        = 4
      VOICE_PING         = 5
      RESUME             = 6
      RECONNECT          = 7
      REQUEST_MEMBERS    = 8
      INVALIDATE_SESSION = 9
      HELLO              = 10
      HEARTBEAT_ACK      = 11
      GUILD_SYNC         = 12
  
      def __init__(self, *args, **kwargs):
          super().__init__(*args, **kwargs)
          self.max_size = None
          # an empty dispatcher to prevent crashes
          self._dispatch = lambda *args: None
          # generic event listeners
          self._dispatch_listeners = []
          # the keep alive
          self._keep_alive = None
  
      @classmethod
      @asyncio.coroutine
      def from_client(cls, client, *, resume=False):
          """Creates a main websocket for Discord from a :class:`Client`.
  
          This is for internal use only.
          """
          gateway = yield from client.http.get_gateway()
          ws = yield from websockets.connect(gateway, loop=client.loop, klass=cls)
  
          # dynamically add attributes needed
          ws.token = client.http.token
          ws._connection = client.connection
          ws._dispatch = client.dispatch
          ws.gateway = gateway
          ws.shard_id = client.shard_id
          ws.shard_count = client.shard_count
  
          client.connection._update_references(ws)
  
          log.info('Created websocket connected to {}'.format(gateway))
  
          # poll the event for OP HELLO
          yield from ws.poll_event()
  
          if not resume:
              yield from ws.identify()
              log.info('sent the identify payload to create the websocket')
              return ws
  
          yield from ws.resume()
          log.info('sent the resume payload to create the websocket')
          try:
              yield from ws.ensure_open()
          except websockets.exceptions.ConnectionClosed:
              # ws got closed so let's just do a regular IDENTIFY connect.
              log.info('RESUME failure.')
              return (yield from cls.from_client(client))
          else:
              return ws
  
      def wait_for(self, event, predicate, result=None):
          """Waits for a DISPATCH'd event that meets the predicate.
  
          Parameters
          -----------
          event : str
              The event name in all upper case to wait for.
          predicate
              A function that takes a data parameter to check for event
              properties. The data parameter is the 'd' key in the JSON message.
          result
              A function that takes the same data parameter and executes to send
              the result to the future. If None, returns the data.
  
          Returns
          --------
          asyncio.Future
              A future to wait for.
          """
  
          future = asyncio.Future(loop=self.loop)
          entry = EventListener(event=event, predicate=predicate, result=result, future=future)
          self._dispatch_listeners.append(entry)
          return future
  
      @asyncio.coroutine
      def identify(self):
          """Sends the IDENTIFY packet."""
          payload = {
              'op': self.IDENTIFY,
              'd': {
                  'token': self.token,
                  'properties': {
                      '$os': sys.platform,
                      '$browser': 'discord.py',
                      '$device': 'discord.py',
                      '$referrer': '',
                      '$referring_domain': ''
                  },
                  'compress': True,
                  'large_threshold': 250,
                  'v': 3
              }
          }
  
          if not self._connection.is_bot:
              payload['d']['synced_guilds'] = []
  
          if self.shard_id is not None and self.shard_count is not None:
              payload['d']['shard'] = [self.shard_id, self.shard_count]
  
          yield from self.send_as_json(payload)
  
      @asyncio.coroutine
      def resume(self):
          """Sends the RESUME packet."""
          state = self._connection
          payload = {
              'op': self.RESUME,
              'd': {
                  'seq': state.sequence,
                  'session_id': state.session_id,
                  'token': self.token
              }
          }
  
          yield from self.send_as_json(payload)
  
      @asyncio.coroutine
      def received_message(self, msg):
          self._dispatch('socket_raw_receive', msg)
  
          if isinstance(msg, bytes):
              msg = zlib.decompress(msg, 15, 10490000) # This is 10 MiB
              msg = msg.decode('utf-8')
  
          msg = json.loads(msg)
          state = self._connection
  
          log.debug('WebSocket Event: {}'.format(msg))
          self._dispatch('socket_response', msg)
  
          op = msg.get('op')
          data = msg.get('d')
  
          if 's' in msg:
              state.sequence = msg['s']
  
          if op == self.RECONNECT:
              # "reconnect" can only be handled by the Client
              # so we terminate our connection and raise an
              # internal exception signalling to reconnect.
              log.info('Received RECONNECT opcode.')
              yield from self.close()
              raise ReconnectWebSocket()
  
          if op == self.HEARTBEAT_ACK:
              return # disable noisy logging for now
  
          if op == self.HEARTBEAT:
              beat = self._keep_alive.get_payload()
              yield from self.send_as_json(beat)
              return
  
          if op == self.HELLO:
              interval = data['heartbeat_interval'] / 1000.0
              self._keep_alive = KeepAliveHandler(ws=self, interval=interval)
              self._keep_alive.start()
              return
  
          if op == self.INVALIDATE_SESSION:
              state.sequence = None
              state.session_id = None
              if data == True:
                  yield from self.close()
                  raise ResumeWebSocket()
  
              yield from self.identify()
              return
  
          if op != self.DISPATCH:
              log.info('Unhandled op {}'.format(op))
              return
  
          event = msg.get('t')
          is_ready = event == 'READY'
  
          if is_ready:
              state.clear()
              state.sequence = msg['s']
              state.session_id = data['session_id']
  
          parser = 'parse_' + event.lower()
  
          try:
              func = getattr(self._connection, parser)
          except AttributeError:
              log.info('Unhandled event {}'.format(event))
          else:
              func(data)
  
          # remove the dispatched listeners
          removed = []
          for index, entry in enumerate(self._dispatch_listeners):
              if entry.event != event:
                  continue
  
              future = entry.future
              if future.cancelled():
                  removed.append(index)
  
              try:
                  valid = entry.predicate(data)
              except Exception as e:
                  future.set_exception(e)
                  removed.append(index)
              else:
                  if valid:
                      ret = data if entry.result is None else entry.result(data)
                      future.set_result(ret)
                      removed.append(index)
  
          for index in reversed(removed):
              del self._dispatch_listeners[index]
  
      def _can_handle_close(self, code):
          return code not in (1000, 4004)
  
      @asyncio.coroutine
      def poll_event(self):
          """Polls for a DISPATCH event and handles the general gateway loop.
  
          Raises
          ------
          ConnectionClosed
              The websocket connection was terminated for unhandled reasons.
          """
          try:
              msg = yield from self.recv()
              yield from self.received_message(msg)
          except websockets.exceptions.ConnectionClosed as e:
              if self._can_handle_close(e.code):
                  log.info('Websocket closed with {0.code} ({0.reason}), attempting a reconnect.'.format(e))
                  raise ResumeWebSocket() from e
              else:
                  raise ConnectionClosed(e) from e
  
      @asyncio.coroutine
      def send(self, data):
          self._dispatch('socket_raw_send', data)
          yield from super().send(data)
  
      @asyncio.coroutine
      def send_as_json(self, data):
          try:
              yield from super().send(utils.to_json(data))
          except websockets.exceptions.ConnectionClosed as e:
              if not self._can_handle_close(e.code):
                  raise ConnectionClosed(e) from e
  
      @asyncio.coroutine
      def change_presence(self, *, game=None, status=None, afk=False, since=0.0, idle=None):
          if game is not None and not isinstance(game, Game):
              raise InvalidArgument('game must be of Game or None')
  
          if idle:
              status = 'idle'
  
          if status == 'idle':
              since = int(time.time() * 1000)
  
          sent_game = dict(game) if game else None
  
          payload = {
              'op': self.PRESENCE,
              'd': {
                  'game': sent_game,
                  'afk': afk,
                  'since': since,
                  'status': status
              }
          }
  
          sent = utils.to_json(payload)
          log.debug('Sending "{}" to change status'.format(sent))
          yield from self.send(sent)
  
          status_enum = try_enum(Status, status)
          if status_enum is Status.invisible:
              status_enum = Status.offline
  
          for server in self._connection.servers:
              me = server.me
              if me is None:
                  continue
  
              me.game = game
              me.status = status_enum
  
      @asyncio.coroutine
      def request_sync(self, guild_ids):
          payload = {
              'op': self.GUILD_SYNC,
              'd': list(guild_ids)
          }
          yield from self.send_as_json(payload)
  
      @asyncio.coroutine
      def voice_state(self, guild_id, channel_id, self_mute=False, self_deaf=False):
          payload = {
              'op': self.VOICE_STATE,
              'd': {
                  'guild_id': guild_id,
                  'channel_id': channel_id,
                  'self_mute': self_mute,
                  'self_deaf': self_deaf
              }
          }
  
          yield from self.send_as_json(payload)
  
          # we're leaving a voice channel so remove it from the client list
          if channel_id is None:
              self._connection._remove_voice_client(guild_id)
  
      @asyncio.coroutine
      def close_connection(self, force=False):
          if self._keep_alive:
              self._keep_alive.stop()
  
          yield from super().close_connection(force=force)
  
  class DiscordVoiceWebSocket(websockets.client.WebSocketClientProtocol):
      """Implements the websocket protocol for handling voice connections.
  
      Attributes
      -----------
      IDENTIFY
          Send only. Starts a new voice session.
      SELECT_PROTOCOL
          Send only. Tells discord what encryption mode and how to connect for voice.
      READY
          Receive only. Tells the websocket that the initial connection has completed.
      HEARTBEAT
          Send only. Keeps your websocket connection alive.
      SESSION_DESCRIPTION
          Receive only. Gives you the secret key required for voice.
      SPEAKING
          Send only. Notifies the client if you are currently speaking.
      """
  
      IDENTIFY            = 0
      SELECT_PROTOCOL     = 1
      READY               = 2
      HEARTBEAT           = 3
      SESSION_DESCRIPTION = 4
      SPEAKING            = 5
  
      def __init__(self, *args, **kwargs):
          super().__init__(*args, **kwargs)
          self.max_size = None
          self._keep_alive = None
  
      @asyncio.coroutine
      def send_as_json(self, data):
          yield from self.send(utils.to_json(data))
  
      @classmethod
      @asyncio.coroutine
      def from_client(cls, client):
          """Creates a voice websocket for the :class:`VoiceClient`."""
          gateway = 'wss://' + client.endpoint
          ws = yield from websockets.connect(gateway, loop=client.loop, klass=cls)
          ws.gateway = gateway
          ws._connection = client
  
          identify = {
              'op': cls.IDENTIFY,
              'd': {
                  'server_id': client.guild_id,
                  'user_id': client.user.id,
                  'session_id': client.session_id,
                  'token': client.token
              }
          }
  
          yield from ws.send_as_json(identify)
          return ws
  
      @asyncio.coroutine
      def select_protocol(self, ip, port):
          payload = {
              'op': self.SELECT_PROTOCOL,
              'd': {
                  'protocol': 'udp',
                  'data': {
                      'address': ip,
                      'port': port,
                      'mode': 'xsalsa20_poly1305'
                  }
              }
          }
  
          yield from self.send_as_json(payload)
          log.debug('Selected protocol as {}'.format(payload))
  
      @asyncio.coroutine
      def speak(self, is_speaking=True):
          payload = {
              'op': self.SPEAKING,
              'd': {
                  'speaking': is_speaking,
                  'delay': 0
              }
          }
  
          yield from self.send_as_json(payload)
          log.debug('Voice speaking now set to {}'.format(is_speaking))
  
      @asyncio.coroutine
      def received_message(self, msg):
          log.debug('Voice websocket frame received: {}'.format(msg))
          op = msg.get('op')
          data = msg.get('d')
  
          if op == self.READY:
              interval = data['heartbeat_interval'] / 1000.0
              self._keep_alive = VoiceKeepAliveHandler(ws=self, interval=interval)
              self._keep_alive.start()
              yield from self.initial_connection(data)
          elif op == self.SESSION_DESCRIPTION:
              yield from self.load_secret_key(data)
  
      @asyncio.coroutine
      def initial_connection(self, data):
          state = self._connection
          state.ssrc = data.get('ssrc')
          state.voice_port = data.get('port')
          packet = bytearray(70)
          struct.pack_into('>I', packet, 0, state.ssrc)
          state.socket.sendto(packet, (state.endpoint_ip, state.voice_port))
          recv = yield from self.loop.sock_recv(state.socket, 70)
          log.debug('received packet in initial_connection: {}'.format(recv))
  
          # the ip is ascii starting at the 4th byte and ending at the first null
          ip_start = 4
          ip_end = recv.index(0, ip_start)
          state.ip = recv[ip_start:ip_end].decode('ascii')
  
          # the port is a little endian unsigned short in the last two bytes
          # yes, this is different endianness from everything else
          state.port = struct.unpack_from('<H', recv, len(recv) - 2)[0]
  
          log.debug('detected ip: {0.ip} port: {0.port}'.format(state))
          yield from self.select_protocol(state.ip, state.port)
          log.info('selected the voice protocol for use')
  
      @asyncio.coroutine
      def load_secret_key(self, data):
          log.info('received secret key for voice connection')
          self._connection.secret_key = data.get('secret_key')
          yield from self.speak()
  
      @asyncio.coroutine
      def poll_event(self):
          try:
              msg = yield from asyncio.wait_for(self.recv(), timeout=30.0, loop=self.loop)
              yield from self.received_message(json.loads(msg))
          except websockets.exceptions.ConnectionClosed as e:
              raise ConnectionClosed(e) from e
  
      @asyncio.coroutine
      def close_connection(self, force=False):
          if self._keep_alive:
              self._keep_alive.stop()
  
          yield from super().close_connection(force=force)
  
  
  