1# Copyright 2015, 2016 OpenMarket Ltd
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#     http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14import logging
15from typing import TYPE_CHECKING, Iterable, List, Optional, Tuple
16
17from synapse.api.constants import ReadReceiptEventFields, ReceiptTypes
18from synapse.appservice import ApplicationService
19from synapse.streams import EventSource
20from synapse.types import JsonDict, ReadReceipt, UserID, get_domain_from_id
21
22if TYPE_CHECKING:
23    from synapse.server import HomeServer
24
25logger = logging.getLogger(__name__)
26
27
28class ReceiptsHandler:
29    def __init__(self, hs: "HomeServer"):
30        self.notifier = hs.get_notifier()
31        self.server_name = hs.config.server.server_name
32        self.store = hs.get_datastore()
33        self.event_auth_handler = hs.get_event_auth_handler()
34
35        self.hs = hs
36
37        # We only need to poke the federation sender explicitly if its on the
38        # same instance. Other federation sender instances will get notified by
39        # `synapse.app.generic_worker.FederationSenderHandler` when it sees it
40        # in the receipts stream.
41        self.federation_sender = None
42        if hs.should_send_federation():
43            self.federation_sender = hs.get_federation_sender()
44
45        # If we can handle the receipt EDUs we do so, otherwise we route them
46        # to the appropriate worker.
47        if hs.get_instance_name() in hs.config.worker.writers.receipts:
48            hs.get_federation_registry().register_edu_handler(
49                "m.receipt", self._received_remote_receipt
50            )
51        else:
52            hs.get_federation_registry().register_instances_for_edu(
53                "m.receipt",
54                hs.config.worker.writers.receipts,
55            )
56
57        self.clock = self.hs.get_clock()
58        self.state = hs.get_state_handler()
59
60    async def _received_remote_receipt(self, origin: str, content: JsonDict) -> None:
61        """Called when we receive an EDU of type m.receipt from a remote HS."""
62        receipts = []
63        for room_id, room_values in content.items():
64            # If we're not in the room just ditch the event entirely. This is
65            # probably an old server that has come back and thinks we're still in
66            # the room (or we've been rejoined to the room by a state reset).
67            is_in_room = await self.event_auth_handler.check_host_in_room(
68                room_id, self.server_name
69            )
70            if not is_in_room:
71                logger.info(
72                    "Ignoring receipt for room %r from server %s as we're not in the room",
73                    room_id,
74                    origin,
75                )
76                continue
77
78            for receipt_type, users in room_values.items():
79                for user_id, user_values in users.items():
80                    if get_domain_from_id(user_id) != origin:
81                        logger.info(
82                            "Received receipt for user %r from server %s, ignoring",
83                            user_id,
84                            origin,
85                        )
86                        continue
87
88                    receipts.append(
89                        ReadReceipt(
90                            room_id=room_id,
91                            receipt_type=receipt_type,
92                            user_id=user_id,
93                            event_ids=user_values["event_ids"],
94                            data=user_values.get("data", {}),
95                        )
96                    )
97
98        await self._handle_new_receipts(receipts)
99
100    async def _handle_new_receipts(self, receipts: List[ReadReceipt]) -> bool:
101        """Takes a list of receipts, stores them and informs the notifier."""
102        min_batch_id: Optional[int] = None
103        max_batch_id: Optional[int] = None
104
105        for receipt in receipts:
106            res = await self.store.insert_receipt(
107                receipt.room_id,
108                receipt.receipt_type,
109                receipt.user_id,
110                receipt.event_ids,
111                receipt.data,
112            )
113
114            if not res:
115                # res will be None if this read receipt is 'old'
116                continue
117
118            stream_id, max_persisted_id = res
119
120            if min_batch_id is None or stream_id < min_batch_id:
121                min_batch_id = stream_id
122            if max_batch_id is None or max_persisted_id > max_batch_id:
123                max_batch_id = max_persisted_id
124
125        # Either both of these should be None or neither.
126        if min_batch_id is None or max_batch_id is None:
127            # no new receipts
128            return False
129
130        affected_room_ids = list({r.room_id for r in receipts})
131
132        self.notifier.on_new_event("receipt_key", max_batch_id, rooms=affected_room_ids)
133        # Note that the min here shouldn't be relied upon to be accurate.
134        await self.hs.get_pusherpool().on_new_receipts(
135            min_batch_id, max_batch_id, affected_room_ids
136        )
137
138        return True
139
140    async def received_client_receipt(
141        self, room_id: str, receipt_type: str, user_id: str, event_id: str, hidden: bool
142    ) -> None:
143        """Called when a client tells us a local user has read up to the given
144        event_id in the room.
145        """
146        receipt = ReadReceipt(
147            room_id=room_id,
148            receipt_type=receipt_type,
149            user_id=user_id,
150            event_ids=[event_id],
151            data={"ts": int(self.clock.time_msec()), "hidden": hidden},
152        )
153
154        is_new = await self._handle_new_receipts([receipt])
155        if not is_new:
156            return
157
158        if self.federation_sender and not (
159            self.hs.config.experimental.msc2285_enabled and hidden
160        ):
161            await self.federation_sender.send_read_receipt(receipt)
162
163
164class ReceiptEventSource(EventSource[int, JsonDict]):
165    def __init__(self, hs: "HomeServer"):
166        self.store = hs.get_datastore()
167        self.config = hs.config
168
169    @staticmethod
170    def filter_out_hidden(events: List[JsonDict], user_id: str) -> List[JsonDict]:
171        visible_events = []
172
173        # filter out hidden receipts the user shouldn't see
174        for event in events:
175            content = event.get("content", {})
176            new_event = event.copy()
177            new_event["content"] = {}
178
179            for event_id in content.keys():
180                event_content = content.get(event_id, {})
181                m_read = event_content.get(ReceiptTypes.READ, {})
182
183                # If m_read is missing copy over the original event_content as there is nothing to process here
184                if not m_read:
185                    new_event["content"][event_id] = event_content.copy()
186                    continue
187
188                new_users = {}
189                for rr_user_id, user_rr in m_read.items():
190                    try:
191                        hidden = user_rr.get("hidden")
192                    except AttributeError:
193                        # Due to https://github.com/matrix-org/synapse/issues/10376
194                        # there are cases where user_rr is a string, in those cases
195                        # we just ignore the read receipt
196                        continue
197
198                    if hidden is not True or rr_user_id == user_id:
199                        new_users[rr_user_id] = user_rr.copy()
200                        # If hidden has a value replace hidden with the correct prefixed key
201                        if hidden is not None:
202                            new_users[rr_user_id].pop("hidden")
203                            new_users[rr_user_id][
204                                ReadReceiptEventFields.MSC2285_HIDDEN
205                            ] = hidden
206
207                # Set new users unless empty
208                if len(new_users.keys()) > 0:
209                    new_event["content"][event_id] = {ReceiptTypes.READ: new_users}
210
211            # Append new_event to visible_events unless empty
212            if len(new_event["content"].keys()) > 0:
213                visible_events.append(new_event)
214
215        return visible_events
216
217    async def get_new_events(
218        self,
219        user: UserID,
220        from_key: int,
221        limit: Optional[int],
222        room_ids: Iterable[str],
223        is_guest: bool,
224        explicit_room_id: Optional[str] = None,
225    ) -> Tuple[List[JsonDict], int]:
226        from_key = int(from_key)
227        to_key = self.get_current_key()
228
229        if from_key == to_key:
230            return [], to_key
231
232        events = await self.store.get_linearized_receipts_for_rooms(
233            room_ids, from_key=from_key, to_key=to_key
234        )
235
236        if self.config.experimental.msc2285_enabled:
237            events = ReceiptEventSource.filter_out_hidden(events, user.to_string())
238
239        return events, to_key
240
241    async def get_new_events_as(
242        self, from_key: int, service: ApplicationService
243    ) -> Tuple[List[JsonDict], int]:
244        """Returns a set of new read receipt events that an appservice
245        may be interested in.
246
247        Args:
248            from_key: the stream position at which events should be fetched from
249            service: The appservice which may be interested
250
251        Returns:
252            A two-tuple containing the following:
253                * A list of json dictionaries derived from read receipts that the
254                  appservice may be interested in.
255                * The current read receipt stream token.
256        """
257        from_key = int(from_key)
258        to_key = self.get_current_key()
259
260        if from_key == to_key:
261            return [], to_key
262
263        # Fetch all read receipts for all rooms, up to a limit of 100. This is ordered
264        # by most recent.
265        rooms_to_events = await self.store.get_linearized_receipts_for_all_rooms(
266            from_key=from_key, to_key=to_key
267        )
268
269        # Then filter down to rooms that the AS can read
270        events = []
271        for room_id, event in rooms_to_events.items():
272            if not await service.matches_user_in_member_list(room_id, self.store):
273                continue
274
275            events.append(event)
276
277        return events, to_key
278
279    def get_current_key(self, direction: str = "f") -> int:
280        return self.store.get_max_receipt_stream_id()
281