fix: support for stable mutual rooms endpoint (#2939)

* add support for stable mutual rooms endpoint

* add stable mutual room feature check

src/app/hooks/useMutualRooms.ts

@@ -1,9 +1,10 @@
 import { useCallback } from 'react';
+import { MatrixClient, Method } from 'matrix-js-sdk';
 import { useMatrixClient } from './useMatrixClient';
 import { AsyncState, useAsyncCallbackValue } from './useAsyncCallback';
 import { useSpecVersions } from './useSpecVersions';
 
-export const useMutualRoomsSupport = (): boolean => {
+export const useUnstableMutualRoomsSupport = (): boolean => {
   const { unstable_features: unstableFeatures } = useSpecVersions();
 
   const supported =
@@ -14,16 +15,59 @@ export const useMutualRoomsSupport = (): boolean => {
   return !!supported;
 };
 
+export const useMutualRoomsSupport = (): boolean => {
+  const { unstable_features: unstableFeatures, versions } = useSpecVersions();
+
+  const supported =
+    versions.includes('v1.19') ||
+    unstableFeatures?.['uk.half-shot.msc2666.query_mutual_rooms.stable'];
+
+  return !!supported;
+};
+
+type MutualRoomsOK = {
+  joined: string[];
+  next_batch?: string;
+  count: number;
+};
+
+const fetchAllMutualRooms = async (mx: MatrixClient, userId: string): Promise<string[]> => {
+  const mutualRooms: Set<string> = new Set();
+
+  let nextBatch: string | undefined;
+  do {
+    // eslint-disable-next-line no-await-in-loop
+    const result = await mx.http.authedRequest<MutualRoomsOK>(
+      Method.Get,
+      '/mutual_rooms',
+      {
+        user_id: userId,
+        from: nextBatch,
+      },
+      undefined,
+      {
+        prefix: '/_matrix/client/v1',
+      }
+    );
+    result.joined.forEach((r) => mutualRooms.add(r));
+    nextBatch = result.next_batch;
+  } while (typeof nextBatch === 'string');
+
+  return Array.from(mutualRooms);
+};
+
 export const useMutualRooms = (userId: string): AsyncState<string[], unknown> => {
   const mx = useMatrixClient();
 
-  const supported = useMutualRoomsSupport();
+  const unstableSupport = useUnstableMutualRoomsSupport();
+  const support = useMutualRoomsSupport();
 
   const [mutualRoomsState] = useAsyncCallbackValue(
-    useCallback(
-      () => (supported ? mx._unstable_getSharedRooms(userId) : Promise.resolve([])),
-      [mx, userId, supported]
-    )
+    useCallback(() => {
+      if (support) return fetchAllMutualRooms(mx, userId);
+      if (unstableSupport) return mx._unstable_getSharedRooms(userId);
+      return Promise.resolve([]);
+    }, [mx, userId, unstableSupport, support])
   );
 
   return mutualRoomsState;