Follow permalinks to and from threads (#5414)

* Implement navigation to event inside a thread when a permalink is used

* Fix permalink navigation in threads to rooms

* Fix navigating to a different thread from a permalink in an existing thread

* Fix tests

* Add missing tests for thread navigation

* Reduce number of diff between ThreadedMessagesNode.kt and MessagesNode.kt

* Navigate back to the room when a link to the current room is clicked in a thread.

---------

Co-authored-by: Benoit Marty <benoitm@element.io>
Co-authored-by: Benoit Marty <benoit@matrix.org>

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/room/BaseRoom.kt

@@ -244,7 +244,9 @@ interface BaseRoom : Closeable {
 
     suspend fun subscribeToCallDecline(notificationEventId: EventId): Flow<UserId>
 
-        /**
+    suspend fun threadRootIdForEvent(eventId: EventId): Result<ThreadId?>
+
+    /**
      * Destroy the room and release all resources associated to it.
      */
     fun destroy()

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/RustBaseRoom.kt

@@ -322,4 +322,12 @@ class RustBaseRoom(
             })
         }
     }
+
+    override suspend fun threadRootIdForEvent(eventId: EventId): Result<ThreadId?> = withContext(roomDispatcher) {
+        runCatchingExceptions {
+            innerRoom.loadOrFetchEvent(eventId.value).use {
+                it.threadRootEventId()?.let(::ThreadId)
+            }
+        }
+    }
 }

libraries/matrix/test/src/main/kotlin/io/element/android/libraries/matrix/test/room/FakeBaseRoom.kt

@@ -71,6 +71,7 @@ class FakeBaseRoom(
     private val forgetResult: () -> Result<Unit> = { lambdaError() },
     private val reportRoomResult: (String?) -> Result<Unit> = { lambdaError() },
     private val predecessorRoomResult: () -> PredecessorRoom? = { null },
+    private val threadRootIdForEventResult: (EventId) -> Result<ThreadId?> = { lambdaError() },
 ) : BaseRoom {
     private val _roomInfoFlow: MutableStateFlow<RoomInfo> = MutableStateFlow(initialRoomInfo)
     override val roomInfoFlow: StateFlow<RoomInfo> = _roomInfoFlow
@@ -244,6 +245,10 @@ class FakeBaseRoom(
     fun givenUpdateMembersResult(result: () -> Unit) {
         updateMembersResult = result
     }
+
+    override suspend fun threadRootIdForEvent(eventId: EventId): Result<ThreadId?> {
+        return threadRootIdForEventResult(eventId)
+    }
 }
 
 fun defaultRoomPowerLevelValues() = RoomPowerLevelsValues(