feat: More advanced create chat methods

This includes a new simplified
API to create new direct and
group chats. It also handles
enabling encryption by
default.

lib/src/client.dart

@@ -556,24 +556,100 @@ class Client extends MatrixApi {
   }
 
   /// Returns an existing direct room ID with this user or creates a new one.
-  /// Returns null on error.
-  Future<String> startDirectChat(String mxid) async {
+  /// By default encryption will be enabled if the client supports encryption
+  /// and the other user has uploaded any encryption keys.
+  Future<String> startDirectChat(
+    String mxid, {
+    bool? enableEncryption,
+    List<StateEvent>? initialState,
+    bool waitForSync = true,
+  }) async {
     // Try to find an existing direct chat
-    var roomId = getDirectChatFromUserId(mxid);
-    if (roomId != null) return roomId;
+    final directChatRoomId = getDirectChatFromUserId(mxid);
+    if (directChatRoomId != null) return directChatRoomId;
+
+    enableEncryption ??= await userOwnsEncryptionKeys(mxid);
+    if (enableEncryption) {
+      initialState ??= [];
+      initialState.add(StateEvent(
+        content: {
+          'algorithm': supportedGroupEncryptionAlgorithms.first,
+        },
+        type: EventTypes.Encryption,
+      ));
+    }
 
     // Start a new direct chat
-    roomId = await createRoom(
+    final roomId = await createRoom(
       invite: [mxid],
       isDirect: true,
       preset: CreateRoomPreset.trustedPrivateChat,
+      initialState: initialState,
     );
 
+    if (waitForSync) {
+      if (getRoomById(roomId) == null) {
+        // Wait for room actually appears in sync
+        await onSync.stream.firstWhere(
+            (sync) => sync.rooms?.join?.containsKey(roomId) ?? false);
+      }
+    }
+
     await Room(id: roomId, client: this).addToDirectChat(mxid);
 
     return roomId;
   }
 
+  /// Simplified method to create a new group chat. By default it is a private
+  /// chat. The encryption is enabled if this client supports encryption and
+  /// the preset is not a public chat.
+  Future<String> createGroupChat({
+    String? groupName,
+    bool? enableEncryption,
+    List<String>? invite,
+    CreateRoomPreset preset = CreateRoomPreset.privateChat,
+    List<StateEvent>? initialState,
+    bool waitForSync = true,
+  }) async {
+    enableEncryption ??=
+        encryptionEnabled && preset != CreateRoomPreset.publicChat;
+    if (enableEncryption) {
+      initialState ??= [];
+      initialState.add(StateEvent(
+        content: {
+          'algorithm': supportedGroupEncryptionAlgorithms.first,
+        },
+        type: EventTypes.Encryption,
+      ));
+    }
+    final roomId = await createRoom(
+      invite: invite,
+      preset: preset,
+      name: groupName,
+      initialState: initialState,
+    );
+
+    if (waitForSync) {
+      if (getRoomById(roomId) == null) {
+        // Wait for room actually appears in sync
+        await onSync.stream.firstWhere(
+            (sync) => sync.rooms?.join?.containsKey(roomId) ?? false);
+      }
+    }
+    return roomId;
+  }
+
+  /// Checks if the given user has encryption keys. May query keys from the
+  /// server to answer this.
+  Future<bool> userOwnsEncryptionKeys(String userId) async {
+    if (userId == userID) return encryptionEnabled;
+    if (_userDeviceKeys.containsKey(userId)) {
+      return true;
+    }
+    final keys = await queryKeys({userId: []});
+    return keys.deviceKeys?.isNotEmpty ?? false;
+  }
+
   /// Creates a new space and returns the Room ID. The parameters are mostly
   /// the same like in [createRoom()].
   /// Be aware that spaces appear in the [rooms] list. You should check if a

lib/src/user.dart

@@ -148,7 +148,17 @@ class User extends Event {
 
   /// Returns an existing direct chat ID with this user or creates a new one.
   /// Returns null on error.
-  Future<String> startDirectChat() async => room.client.startDirectChat(id);
+  Future<String> startDirectChat({
+    bool? enableEncryption,
+    List<StateEvent>? initialState,
+    bool waitForSync = true,
+  }) async =>
+      room.client.startDirectChat(
+        id,
+        enableEncryption: enableEncryption,
+        initialState: initialState,
+        waitForSync: waitForSync,
+      );
 
   /// The newest presence of this user if there is any and null if not.
   Presence? get presence => room.client.presences[id];

test/client_test.dart

@@ -560,6 +560,12 @@ void main() {
           bunnyContent);
       await client.dispose(closeDatabase: true);
     });
+    test('startDirectChat', () async {
+      await matrix.startDirectChat('@alice:example.com', waitForSync: false);
+    });
+    test('createGroupChat', () async {
+      await matrix.createGroupChat(groupName: 'Testgroup', waitForSync: false);
+    });
     test('Test the fake store api', () async {
       final database = await getDatabase(null);
       final client1 = Client(

test/user_test.dart

@@ -118,7 +118,7 @@ void main() {
       await user1.setPower(50);
     });
     test('startDirectChat', () async {
-      await user1.startDirectChat();
+      await user1.startDirectChat(waitForSync: false);
     });
     test('getPresence', () async {
       await client.handleSync(SyncUpdate.fromJson({