gateway.websocket: add basic vsu handling

this adds *theoretical* interfaces to a VoiceManager. The actual
VoiceManager does not work and probably any VSU being sent over will
crash the websocket with an AttributionError.

 - enums: add VOICE_CHANNELS
 - run: add App.voice attribute

litecord/enums.py

@@ -83,6 +83,12 @@ GUILD_CHANS = (ChannelType.GUILD_TEXT,
                ChannelType.GUILD_CATEGORY)
 
 
+VOICE_CHANNELS = (
+    ChannelType.DM, ChannelType.GUILD_VOICE,
+    ChannelType.GUILD_CATEGORY
+)
+
+
 class ActivityType(EasyEnum):
     PLAYING = 0
     STREAMING = 1

litecord/gateway/websocket.py

@@ -30,12 +30,12 @@ from logbook import Logger
 import earl
 
 from litecord.auth import raw_token_check
-from litecord.enums import RelationshipType
+from litecord.enums import RelationshipType, ChannelType, VOICE_CHANNELS
 from litecord.schemas import validate, GW_STATUS_UPDATE
 from litecord.utils import (
     task_wrapper, LitecordJSONEncoder, yield_chunks
 )
-from litecord.permissions import get_permissions
+from litecord.permissions import get_permissions, ALL_PERMISSIONS
 
 from litecord.gateway.opcodes import OP
 from litecord.gateway.state import GatewayState
@@ -48,14 +48,17 @@ from litecord.gateway.errors import (
 )
 
 log = Logger(__name__)
+
 WebsocketProperties = collections.namedtuple(
     'WebsocketProperties', 'v encoding compress zctx tasks'
 )
 
 WebsocketObjects = collections.namedtuple(
-    'WebsocketObjects', ('db', 'state_manager', 'storage',
-                         'loop', 'dispatcher', 'presence', 'ratelimiter',
-                         'user_storage')
+    'WebsocketObjects', (
+        'db', 'state_manager', 'storage',
+        'loop', 'dispatcher', 'presence', 'ratelimiter',
+        'user_storage', 'voice'
+    )
 )
 
 
@@ -113,7 +116,7 @@ class GatewayWebsocket:
         self.ext = WebsocketObjects(
             app.db, app.state_manager, app.storage, app.loop,
             app.dispatcher, app.presence, app.ratelimiter,
-            app.user_storage
+            app.user_storage, app.voice
         )
 
         self.storage = self.ext.storage
@@ -598,16 +601,93 @@ class GatewayWebsocket:
         # setting new presence to state
         await self.update_status(presence)
 
+    @property
+    def voice_key(self):
+        """Voice state key."""
+        return (self.state.user_id, self.state.session_id)
+
+    async def _voice_check(self, guild_id: int, channel_id: int):
+        """Check if the user can join the given guild/channel pair."""
+        guild = None
+        if guild_id:
+            guild = await self.storage.get_guild(guild_id)
+
+        channel = await self.storage.get_channel(channel_id)
+        ctype = ChannelType(channel['type'])
+
+        if ctype not in VOICE_CHANNELS:
+            return
+
+        if guild and channel.get(['guild_id']) != guild['id']:
+            return
+
+        is_guild_voice = ctype == ChannelType.GUILD_VOICE
+
+        states = await self.ext.voice.state_count(channel_id)
+        perms = (ALL_PERMISSIONS
+                 if not is_guild_voice else
+                 await get_permissions(self.state.user_id,
+                                       channel_id, storage=self.storage)
+                )
+
+        is_full = states >= channel['user_limit']
+        is_bot = self.state.bot
+
+        is_manager = perms.bits.manage_channels
+
+        # if the channel is full AND:
+        #  - user is not a bot
+        #  - user is not manage channels
+        # then it fails
+        if not is_bot and not is_manager and is_full:
+            return
+
+        # all checks passed.
+        return True
+
+    async def _move_voice(self, guild_id, channel_id):
+        """Move an existing voice state to the given target."""
+        if channel_id is None:
+            return await self.ext.voice.del_state(self.voice_key)
+
+        if not await self._voice_check(guild_id, channel_id):
+            return
+
+        await self.ext.voice.move_state(
+            self.voice_key, guild_id, channel_id)
+
+    async def _create_voice(self, guild_id, channel_id):
+        """Create a voice state."""
+        if not await self._voice_check(guild_id, channel_id):
+            return
+
+        await self.ext.voice.create_state(self.voice_key, guild_id, channel_id)
+
     async def handle_4(self, payload: Dict[str, Any]):
         """Handle OP 4 Voice Status Update."""
         data = payload['d']
-        # for now, ignore
-        log.debug('got VSU cid={} gid={} deaf={} mute={} video={}',
-                  data.get('channel_id'),
-                  data.get('guild_id'),
-                  data.get('self_deaf'),
-                  data.get('self_mute'),
-                  data.get('self_video'))
+
+        if not self.state:
+            return
+
+        try:
+            channel_id = int(data['channel_id'])
+            guild_id = int(data['guild_id'])
+
+            # TODO: fetch from settings if not provided
+            # self_deaf = bool(data['self_deaf'])
+            # self_mute = bool(data['self_mute'])
+
+            # NOTE: self_video is NOT handled.
+        except (KeyError, ValueError):
+            pass
+
+        # fetch an existing voice state
+        user_id, session_id = self.state.user_id, self.state.session_id
+        voice_state = await self.ext.voice.fetch_state(user_id, session_id)
+
+        func = self._move_voice if voice_state else self._create_voice
+        await func(guild_id, channel_id)
 
     async def _handle_5(self, payload: Dict[str, Any]):
         """Handle OP 5 Voice Server Ping.

litecord/voice/manager.py

@@ -0,0 +1,23 @@
+"""
+
+Litecord
+Copyright (C) 2018-2019  Luna Mendes
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 3 of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+
+class VoiceManager:
+    """Main voice manager class."""
+    def __init__(self, app):
+        self.app = app

run.py

@@ -70,6 +70,7 @@ from litecord.dispatcher import EventDispatcher
 from litecord.presence import PresenceManager
 from litecord.images import IconManager
 from litecord.jobs import JobManager
+from litecord.voice.manager import VoiceManager
 
 from litecord.utils import LitecordJSONEncoder
 
@@ -232,6 +233,8 @@ def init_app_managers(app_):
 
     app_.storage.presence = app_.presence
 
+    app_.voice = VoiceManager(app_)
+
 
 async def api_index(app_):
     to_find = {}