Implement changes to MSC2285 (hidden read receipts) (#12168)

* Changes hidden read receipts to be a separate receipt type
  (instead of a field on `m.read`).
* Updates the `/receipts` endpoint to accept `m.fully_read`.

synapse/rest/client/receipts.py

@@ -16,8 +16,8 @@ import logging
 import re
 from typing import TYPE_CHECKING, Tuple
 
-from synapse.api.constants import ReadReceiptEventFields, ReceiptTypes
-from synapse.api.errors import Codes, SynapseError
+from synapse.api.constants import ReceiptTypes
+from synapse.api.errors import SynapseError
 from synapse.http import get_request_user_agent
 from synapse.http.server import HttpServer
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
@@ -46,6 +46,7 @@ class ReceiptRestServlet(RestServlet):
         self.hs = hs
         self.auth = hs.get_auth()
         self.receipts_handler = hs.get_receipts_handler()
+        self.read_marker_handler = hs.get_read_marker_handler()
         self.presence_handler = hs.get_presence_handler()
 
     async def on_POST(
@@ -53,7 +54,19 @@ class ReceiptRestServlet(RestServlet):
     ) -> Tuple[int, JsonDict]:
         requester = await self.auth.get_user_by_req(request)
 
-        if receipt_type != ReceiptTypes.READ:
+        if self.hs.config.experimental.msc2285_enabled and receipt_type not in [
+            ReceiptTypes.READ,
+            ReceiptTypes.READ_PRIVATE,
+            ReceiptTypes.FULLY_READ,
+        ]:
+            raise SynapseError(
+                400,
+                "Receipt type must be 'm.read', 'org.matrix.msc2285.read.private' or 'm.fully_read'",
+            )
+        elif (
+            not self.hs.config.experimental.msc2285_enabled
+            and receipt_type != ReceiptTypes.READ
+        ):
             raise SynapseError(400, "Receipt type must be 'm.read'")
 
         # Do not allow older SchildiChat and Element Android clients (prior to Element/1.[012].x) to send an empty body.
@@ -62,26 +75,24 @@ class ReceiptRestServlet(RestServlet):
         if "Android" in user_agent:
             if pattern.match(user_agent) or "Riot" in user_agent:
                 allow_empty_body = True
-        body = parse_json_object_from_request(request, allow_empty_body)
-        hidden = body.get(ReadReceiptEventFields.MSC2285_HIDDEN, False)
-
-        if not isinstance(hidden, bool):
-            raise SynapseError(
-                400,
-                "Param %s must be a boolean, if given"
-                % ReadReceiptEventFields.MSC2285_HIDDEN,
-                Codes.BAD_JSON,
-            )
+        # This call makes sure possible empty body is handled correctly
+        parse_json_object_from_request(request, allow_empty_body)
 
         await self.presence_handler.bump_presence_active_time(requester.user)
 
-        await self.receipts_handler.received_client_receipt(
-            room_id,
-            receipt_type,
-            user_id=requester.user.to_string(),
-            event_id=event_id,
-            hidden=hidden,
-        )
+        if receipt_type == ReceiptTypes.FULLY_READ:
+            await self.read_marker_handler.received_client_read_marker(
+                room_id,
+                user_id=requester.user.to_string(),
+                event_id=event_id,
+            )
+        else:
+            await self.receipts_handler.received_client_receipt(
+                room_id,
+                receipt_type,
+                user_id=requester.user.to_string(),
+                event_id=event_id,
+            )
 
         return 200, {}