flutter-samples/packages/chatty/lib/data/local/stream_api_local_impl.dart

import 'package:stream_chatter/data/stream_api_repository.dart';
import 'package:stream_chatter/domain/models/chat_user.dart';
import 'package:stream_chat_flutter/stream_chat_flutter.dart';

class StreamApiLocalImpl extends StreamApiRepository {
  StreamApiLocalImpl(this._client);

  final StreamChatClient _client;

  @override
  Future<ChatUser> connectUser(ChatUser user, String? token) async {
    Map<String, dynamic> extraData = {};
    if (user.image != null) {
      extraData['image'] = user.image;
    }
    if (user.name != null) {
      extraData['name'] = user.name;
    }
    await _client.disconnect();
    await _client.connectUser(
      User(id: user.id!, extraData: extraData as Map<String, Object>),
      token,
    );
    return user;
  }

  @override
  Future<List<ChatUser>> getChatUsers() async {
    final result = await _client.queryUsers();
    final chatUsers = result.users
        .where((element) => element.id != _client.state.user!.id)
        .map(
          (e) => ChatUser(
            id: e.id,
            name: e.name,
            image: e.extraData['image'] as String?,
          ),
        )
        .toList();
    return chatUsers;
  }

  @override
  Future<String> getToken(String userId) async {
    return _client.devToken(userId);
  }

  @override
  Future<Channel> createGroupChat(
      String channelId, String? name, List<String?>? members,
      {String? image}) async {
    final channel = _client.channel('messaging', id: channelId, extraData: {
      'name': name!,
      'image': image!,
      'members': [_client.state.user!.id, ...members!],
    });
    await channel.watch();
    return channel;
  }

  @override
  Future<Channel> createSimpleChat(String? friendId) async {
    final channel = _client.channel('messaging',
        id: '${_client.state.user!.id.hashCode}${friendId.hashCode}',
        extraData: {
          'members': [
            friendId,
            _client.state.user!.id,
          ],
        });
    await channel.watch();
    return channel;
  }

  @override
  Future<void> logout() {
    return _client.disconnect();
  }

  @override
  Future<bool> connectIfExist(String userId) async {
    final token = await getToken(userId);
    await _client.connectUser(
      User(id: userId),
      token,
    );
    return _client.state.user!.name != null && _client.state.user!.name != userId;
  }
}