Prepare utils for local rooms (#9084)

* Prepare utils for local rooms

* Split up direct-messages module

src/utils/localRoom/isRoomReady.ts

@@ -0,0 +1,47 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { EventType, MatrixClient } from "matrix-js-sdk/src/matrix";
+
+import { LocalRoom } from "../../models/LocalRoom";
+
+/**
+ * Tests whether a room created based on a local room is ready.
+ */
+export function isRoomReady(
+    client: MatrixClient,
+    localRoom: LocalRoom,
+): boolean {
+    // not ready if no actual room id exists
+    if (!localRoom.actualRoomId) return false;
+
+    const room = client.getRoom(localRoom.actualRoomId);
+    // not ready if the room does not exist
+    if (!room) return false;
+
+    // not ready if not all members joined/invited
+    if (room.getInvitedAndJoinedMemberCount() !== 1 + localRoom.targets?.length) return false;
+
+    const roomHistoryVisibilityEvents = room.currentState.getStateEvents(EventType.RoomHistoryVisibility);
+    // not ready if the room history has not been configured
+    if (roomHistoryVisibilityEvents.length === 0) return false;
+
+    const roomEncryptionEvents = room.currentState.getStateEvents(EventType.RoomEncryption);
+    // not ready if encryption has not been configured (applies only to encrypted rooms)
+    if (localRoom.encrypted === true && roomEncryptionEvents.length === 0) return false;
+
+    return true;
+}