import 'package:connectivity_plus/connectivity_plus.dart';

import '../constants/app_enum.dart';

class NetworkService {
  final Connectivity _connectivity = Connectivity();

  Stream<NetworkStatus> watchNetwork() async* {
    // 初始状态
    final initial = await _connectivity.checkConnectivity();
    yield _map(initial);
    // 持续监听
    await for (final result
    in _connectivity.onConnectivityChanged) {
      yield _map(result);
    }
  }

  NetworkStatus _map(List<ConnectivityResult> results) {
    // 优先返回 wifi，其次是 mobile，最后是 none
    if (results.contains(ConnectivityResult.wifi)) {
      return NetworkStatus.wifi;
    }
    if (results.contains(ConnectivityResult.mobile)) {
      return NetworkStatus.mobile;
    }
    return NetworkStatus.none;
  }
}