synapse/synapse/handlers/message.py

# -*- coding: utf-8 -*-
# Copyright 2014, 2015 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from twisted.internet import defer

from synapse.api.constants import EventTypes, Membership
from synapse.api.errors import SynapseError
from synapse.streams.config import PaginationConfig
from synapse.events.utils import serialize_event
from synapse.events.validator import EventValidator
from synapse.util import unwrapFirstError
from synapse.util.logcontext import PreserveLoggingContext
from synapse.types import UserID, RoomStreamToken, StreamToken

from ._base import BaseHandler

import logging

logger = logging.getLogger(__name__)


class MessageHandler(BaseHandler):

    def __init__(self, hs):
        super(MessageHandler, self).__init__(hs)
        self.hs = hs
        self.state = hs.get_state_handler()
        self.clock = hs.get_clock()
        self.validator = EventValidator()

    @defer.inlineCallbacks
    def get_message(self, msg_id=None, room_id=None, sender_id=None,
                    user_id=None):
        """ Retrieve a message.

        Args:
            msg_id (str): The message ID to obtain.
            room_id (str): The room where the message resides.
            sender_id (str): The user ID of the user who sent the message.
            user_id (str): The user ID of the user making this request.
        Returns:
            The message, or None if no message exists.
        Raises:
            SynapseError if something went wrong.
        """
        yield self.auth.check_joined_room(room_id, user_id)

        # Pull out the message from the db
#        msg = yield self.store.get_message(
#            room_id=room_id,
#            msg_id=msg_id,
#            user_id=sender_id
#        )

        # TODO (erikj): Once we work out the correct c-s api we need to think
        # on how to do this.

        defer.returnValue(None)

    @defer.inlineCallbacks
    def get_messages(self, user_id=None, room_id=None, pagin_config=None,
                     as_client_event=True):
        """Get messages in a room.

        Args:
            user_id (str): The user requesting messages.
            room_id (str): The room they want messages from.
            pagin_config (synapse.api.streams.PaginationConfig): The pagination
            config rules to apply, if any.
            as_client_event (bool): True to get events in client-server format.
        Returns:
            dict: Pagination API results
        """
        member_event = yield self.auth.check_user_was_in_room(room_id, user_id)

        data_source = self.hs.get_event_sources().sources["room"]

        if pagin_config.from_token:
            room_token = pagin_config.from_token.room_key
        else:
            pagin_config.from_token = (
                yield self.hs.get_event_sources().get_current_token(
                    direction='b'
                )
            )
            room_token = pagin_config.from_token.room_key

        room_token = RoomStreamToken.parse(room_token)
        if room_token.topological is None:
            raise SynapseError(400, "Invalid token")

        pagin_config.from_token = pagin_config.from_token.copy_and_replace(
            "room_key", str(room_token)
        )

        source_config = pagin_config.get_source_config("room")

        if member_event.membership == Membership.LEAVE:
            # If they have left the room then clamp the token to be before
            # they left the room
            leave_token = yield self.store.get_topological_token_for_event(
                member_event.event_id
            )
            leave_token = RoomStreamToken.parse(leave_token)
            if leave_token.topological < room_token.topological:
                source_config.from_key = str(leave_token)

            if source_config.direction == "f":
                if source_config.to_key is None:
                    source_config.to_key = str(leave_token)
                else:
                    to_token = RoomStreamToken.parse(source_config.to_key)
                    if leave_token.topological < to_token.topological:
                        source_config.to_key = str(leave_token)

        yield self.hs.get_handlers().federation_handler.maybe_backfill(
            room_id, room_token.topological
        )

        user = UserID.from_string(user_id)

        events, next_key = yield data_source.get_pagination_rows(
            user, source_config, room_id
        )

        next_token = pagin_config.from_token.copy_and_replace(
            "room_key", next_key
        )

        if not events:
            defer.returnValue({
                "chunk": [],
                "start": pagin_config.from_token.to_string(),
                "end": next_token.to_string(),
            })

        events = yield self._filter_events_for_client(user_id, room_id, events)

        time_now = self.clock.time_msec()

        chunk = {
            "chunk": [
                serialize_event(e, time_now, as_client_event)
                for e in events
            ],
            "start": pagin_config.from_token.to_string(),
            "end": next_token.to_string(),
        }

        defer.returnValue(chunk)

    @defer.inlineCallbacks
    def _filter_events_for_client(self, user_id, room_id, events):
        event_id_to_state = yield self.store.get_state_for_events(
            room_id, frozenset(e.event_id for e in events),
            types=(
                (EventTypes.RoomHistoryVisibility, ""),
                (EventTypes.Member, user_id),
            )
        )

        def allowed(event, state):
            if event.type == EventTypes.RoomHistoryVisibility:
                return True

            membership_ev = state.get((EventTypes.Member, user_id), None)
            if membership_ev:
                membership = membership_ev.membership
            else:
                membership = Membership.LEAVE

            if membership == Membership.JOIN:
                return True

            history = state.get((EventTypes.RoomHistoryVisibility, ''), None)
            if history:
                visibility = history.content.get("history_visibility", "shared")
            else:
                visibility = "shared"

            if visibility == "public":
                return True
            elif visibility == "shared":
                return True
            elif visibility == "joined":
                return membership == Membership.JOIN
            elif visibility == "invited":
                return membership == Membership.INVITE

            return True

        defer.returnValue([
            event
            for event in events
            if allowed(event, event_id_to_state[event.event_id])
        ])

    @defer.inlineCallbacks
    def create_and_send_event(self, event_dict, ratelimit=True,
                              token_id=None, txn_id=None):
        """ Given a dict from a client, create and handle a new event.

        Creates an FrozenEvent object, filling out auth_events, prev_events,
        etc.

        Adds display names to Join membership events.

        Persists and notifies local clients and federation.

        Args:
            event_dict (dict): An entire event
        """
        builder = self.event_builder_factory.new(event_dict)

        self.validator.validate_new(builder)

        if ratelimit:
            self.ratelimit(builder.user_id)
        # TODO(paul): Why does 'event' not have a 'user' object?
        user = UserID.from_string(builder.user_id)
        assert self.hs.is_mine(user), "User must be our own: %s" % (user,)

        if builder.type == EventTypes.Member:
            membership = builder.content.get("membership", None)
            if membership == Membership.JOIN:
                joinee = UserID.from_string(builder.state_key)
                # If event doesn't include a display name, add one.
                yield self.distributor.fire(
                    "collect_presencelike_data",
                    joinee,
                    builder.content
                )

        if token_id is not None:
            builder.internal_metadata.token_id = token_id

        if txn_id is not None:
            builder.internal_metadata.txn_id = txn_id

        event, context = yield self._create_new_client_event(
            builder=builder,
        )

        if event.type == EventTypes.Member:
            member_handler = self.hs.get_handlers().room_member_handler
            yield member_handler.change_membership(event, context)
        else:
            yield self.handle_new_client_event(
                event=event,
                context=context,
            )

        if event.type == EventTypes.Message:
            presence = self.hs.get_handlers().presence_handler
            with PreserveLoggingContext():
                presence.bump_presence_active_time(user)

        defer.returnValue(event)

    @defer.inlineCallbacks
    def get_room_data(self, user_id=None, room_id=None,
                      event_type=None, state_key=""):
        """ Get data from a room.

        Args:
            event : The room path event
        Returns:
            The path data content.
        Raises:
            SynapseError if something went wrong.
        """
        member_event = yield self.auth.check_user_was_in_room(room_id, user_id)

        if member_event.membership == Membership.JOIN:
            data = yield self.state_handler.get_current_state(
                room_id, event_type, state_key
            )
        elif member_event.membership == Membership.LEAVE:
            key = (event_type, state_key)
            room_state = yield self.store.get_state_for_events(
                room_id, [member_event.event_id], [key]
            )
            data = room_state[member_event.event_id].get(key)

        defer.returnValue(data)

    @defer.inlineCallbacks
    def get_state_events(self, user_id, room_id):
        """Retrieve all state events for a given room. If the user is
        joined to the room then return the current state. If the user has
        left the room return the state events from when they left.

        Args:
            user_id(str): The user requesting state events.
            room_id(str): The room ID to get all state events from.
        Returns:
            A list of dicts representing state events. [{}, {}, {}]
        """
        member_event = yield self.auth.check_user_was_in_room(room_id, user_id)

        if member_event.membership == Membership.JOIN:
            room_state = yield self.state_handler.get_current_state(room_id)
        elif member_event.membership == Membership.LEAVE:
            room_state = yield self.store.get_state_for_events(
                room_id, [member_event.event_id], None
            )
            room_state = room_state[member_event.event_id]

        now = self.clock.time_msec()
        defer.returnValue(
            [serialize_event(c, now) for c in room_state.values()]
        )

    @defer.inlineCallbacks
    def snapshot_all_rooms(self, user_id=None, pagin_config=None, as_client_event=True):
        """Retrieve a snapshot of all rooms the user is invited or has joined.

        This snapshot may include messages for all rooms where the user is
        joined, depending on the pagination config.

        Args:
            user_id (str): The ID of the user making the request.
            pagin_config (synapse.api.streams.PaginationConfig): The pagination
            config used to determine how many messages *PER ROOM* to return.
            as_client_event (bool): True to get events in client-server format.
        Returns:
            A list of dicts with "room_id" and "membership" keys for all rooms
            the user is currently invited or joined in on. Rooms where the user
            is joined on, may return a "messages" key with messages, depending
            on the specified PaginationConfig.
        """
        room_list = yield self.store.get_rooms_for_user_where_membership_is(
            user_id=user_id,
            membership_list=[
                Membership.INVITE, Membership.JOIN, Membership.LEAVE
            ]
        )

        user = UserID.from_string(user_id)

        rooms_ret = []

        now_token = yield self.hs.get_event_sources().get_current_token()

        presence_stream = self.hs.get_event_sources().sources["presence"]
        pagination_config = PaginationConfig(from_token=now_token)
        presence, _ = yield presence_stream.get_pagination_rows(
            user, pagination_config.get_source_config("presence"), None
        )

        receipt_stream = self.hs.get_event_sources().sources["receipt"]
        receipt, _ = yield receipt_stream.get_pagination_rows(
            user, pagination_config.get_source_config("receipt"), None
        )

        public_room_ids = yield self.store.get_public_room_ids()

        limit = pagin_config.limit
        if limit is None:
            limit = 10

        @defer.inlineCallbacks
        def handle_room(event):
            d = {
                "room_id": event.room_id,
                "membership": event.membership,
                "visibility": (
                    "public" if event.room_id in public_room_ids
                    else "private"
                ),
            }

            if event.membership == Membership.INVITE:
                d["inviter"] = event.sender

            rooms_ret.append(d)

            if event.membership not in (Membership.JOIN, Membership.LEAVE):
                return

            try:
                if event.membership == Membership.JOIN:
                    room_end_token = now_token.room_key
                    deferred_room_state = self.state_handler.get_current_state(
                        event.room_id
                    )
                elif event.membership == Membership.LEAVE:
                    room_end_token = "s%d" % (event.stream_ordering,)
                    deferred_room_state = self.store.get_state_for_events(
                        event.room_id, [event.event_id], None
                    )
                    deferred_room_state.addCallback(
                        lambda states: states[event.event_id]
                    )

                (messages, token), current_state = yield defer.gatherResults(
                    [
                        self.store.get_recent_events_for_room(
                            event.room_id,
                            limit=limit,
                            end_token=room_end_token,
                        ),
                        deferred_room_state,
                    ]
                ).addErrback(unwrapFirstError)

                messages = yield self._filter_events_for_client(
                    user_id, event.room_id, messages
                )

                start_token = now_token.copy_and_replace("room_key", token[0])
                end_token = now_token.copy_and_replace("room_key", token[1])
                time_now = self.clock.time_msec()

                d["messages"] = {
                    "chunk": [
                        serialize_event(m, time_now, as_client_event)
                        for m in messages
                    ],
                    "start": start_token.to_string(),
                    "end": end_token.to_string(),
                }

                d["state"] = [
                    serialize_event(c, time_now, as_client_event)
                    for c in current_state.values()
                ]
            except:
                logger.exception("Failed to get snapshot")

        # Only do N rooms at once
        n = 5
        d_list = [handle_room(e) for e in room_list]
        for i in range(0, len(d_list), n):
            yield defer.gatherResults(
                d_list[i:i + n],
                consumeErrors=True
            ).addErrback(unwrapFirstError)

        ret = {
            "rooms": rooms_ret,
            "presence": presence,
            "receipts": receipt,
            "end": now_token.to_string(),
        }

        defer.returnValue(ret)

    @defer.inlineCallbacks
    def room_initial_sync(self, user_id, room_id, pagin_config=None):
        """Capture the a snapshot of a room. If user is currently a member of
        the room this will be what is currently in the room. If the user left
        the room this will be what was in the room when they left.

        Args:
            user_id(str): The user to get a snapshot for.
            room_id(str): The room to get a snapshot of.
            pagin_config(synapse.streams.config.PaginationConfig):
                The pagination config used to determine how many messages to
                return.
        Raises:
            AuthError if the user wasn't in the room.
        Returns:
            A JSON object with the snapshot of the room.
        """

        member_event = yield self.auth.check_user_was_in_room(room_id, user_id)

        if member_event.membership == Membership.JOIN:
            result = yield self._room_initial_sync_joined(
                user_id, room_id, pagin_config, member_event
            )
        elif member_event.membership == Membership.LEAVE:
            result = yield self._room_initial_sync_parted(
                user_id, room_id, pagin_config, member_event
            )
        defer.returnValue(result)

    @defer.inlineCallbacks
    def _room_initial_sync_parted(self, user_id, room_id, pagin_config,
                                  member_event):
        room_state = yield self.store.get_state_for_events(
            member_event.room_id, [member_event.event_id], None
        )

        room_state = room_state[member_event.event_id]

        limit = pagin_config.limit if pagin_config else None
        if limit is None:
            limit = 10

        stream_token = yield self.store.get_stream_token_for_event(
            member_event.event_id
        )

        messages, token = yield self.store.get_recent_events_for_room(
            room_id,
            limit=limit,
            end_token=stream_token
        )

        messages = yield self._filter_events_for_client(
            user_id, room_id, messages
        )

        start_token = StreamToken(token[0], 0, 0, 0)
        end_token = StreamToken(token[1], 0, 0, 0)

        time_now = self.clock.time_msec()

        defer.returnValue({
            "membership": member_event.membership,
            "room_id": room_id,
            "messages": {
                "chunk": [serialize_event(m, time_now) for m in messages],
                "start": start_token.to_string(),
                "end": end_token.to_string(),
            },
            "state": [serialize_event(s, time_now) for s in room_state.values()],
            "presence": [],
            "receipts": [],
        })

    @defer.inlineCallbacks
    def _room_initial_sync_joined(self, user_id, room_id, pagin_config,
                                  member_event):
        current_state = yield self.state.get_current_state(
            room_id=room_id,
        )

        # TODO(paul): I wish I was called with user objects not user_id
        #   strings...
        auth_user = UserID.from_string(user_id)

        # TODO: These concurrently
        time_now = self.clock.time_msec()
        state = [
            serialize_event(x, time_now)
            for x in current_state.values()
        ]

        now_token = yield self.hs.get_event_sources().get_current_token()

        limit = pagin_config.limit if pagin_config else None
        if limit is None:
            limit = 10

        room_members = [
            m for m in current_state.values()
            if m.type == EventTypes.Member
            and m.content["membership"] == Membership.JOIN
        ]

        presence_handler = self.hs.get_handlers().presence_handler

        @defer.inlineCallbacks
        def get_presence():
            states = yield presence_handler.get_states(
                target_users=[UserID.from_string(m.user_id) for m in room_members],
                auth_user=auth_user,
                as_event=True,
                check_auth=False,
            )

            defer.returnValue(states.values())

        receipts_handler = self.hs.get_handlers().receipts_handler

        presence, receipts, (messages, token) = yield defer.gatherResults(
            [
                get_presence(),
                receipts_handler.get_receipts_for_room(room_id, now_token.receipt_key),
                self.store.get_recent_events_for_room(
                    room_id,
                    limit=limit,
                    end_token=now_token.room_key,
                )
            ],
            consumeErrors=True,
        ).addErrback(unwrapFirstError)

        messages = yield self._filter_events_for_client(
            user_id, room_id, messages
        )

        start_token = now_token.copy_and_replace("room_key", token[0])
        end_token = now_token.copy_and_replace("room_key", token[1])

        time_now = self.clock.time_msec()

        defer.returnValue({
            "membership": member_event.membership,
            "room_id": room_id,
            "messages": {
                "chunk": [serialize_event(m, time_now) for m in messages],
                "start": start_token.to_string(),
                "end": end_token.to_string(),
            },
            "state": state,
            "presence": presence,
            "receipts": receipts,
        })