feat(ffi): Add Room::load_or_fetch_event to the FFI layer

This way we can retrieve random events in a room and check their properties - this is needed to decide whether a permalink for an event should open in a thread or not

bindings/matrix-sdk-ffi/src/room/mod.rs

@@ -27,7 +27,7 @@ use ruma::{
             join_rules::JoinRule as RumaJoinRule, message::RoomMessageEventContentWithoutRelation,
             MediaSource,
         },
-        AnyMessageLikeEventContent, AnySyncTimelineEvent,
+        AnyMessageLikeEventContent, AnySyncTimelineEvent, AnyTimelineEvent,
     },
     EventId, Int, OwnedDeviceId, OwnedRoomOrAliasId, OwnedServerName, OwnedUserId, RoomAliasId,
     ServerName, UserId,
@@ -39,6 +39,7 @@ use crate::{
     chunk_iterator::ChunkIterator,
     client::{JoinRule, RoomVisibility},
     error::{ClientError, MediaInfoError, NotYetImplemented, RoomError},
+    event::TimelineEvent,
     identity_status_change::IdentityStatusChange,
     live_location_share::{LastLocation, LiveLocationShare},
     room_member::{RoomMember, RoomMemberWithSenderInfo},
@@ -1178,6 +1179,17 @@ impl Room {
             .await?
             .map(|sub| ThreadSubscription { automatic: sub.automatic }))
     }
+
+    /// Either loads the event associated with the `event_id` from the event
+    /// cache or fetches it from the homeserver.
+    pub async fn load_or_fetch_event(
+        &self,
+        event_id: String,
+    ) -> Result<TimelineEvent, ClientError> {
+        let event_id = EventId::parse(event_id)?;
+        let timeline_event = self.inner.load_or_fetch_event(&event_id, None).await?;
+        Ok(timeline_event.kind.into_raw().deserialize_as_unchecked::<AnyTimelineEvent>()?.into())
+    }
 }
 
 /// A thread subscription (MSC4306).