Аутентификация телефона Flutter Firebase с BLoC

Я пытаюсь добиться аутентификации телефона Firebase с помощью шаблона BLoC.

Это мой блочный класс

class AuthBloc extends Bloc<AuthEvent, AuthState> {
  final AuthProvider authProvider;

  AuthBloc({this.authProvider}) : assert(authProvider!= null);

  @override
  AuthState get initialState => Uninitialized();

  @override
  Stream<AuthState> mapEventToState(AuthEvent event) async* {
    if (event is AppLaunched) {
      yield* _mapAppLaunchedToState();
    } else if(event is OtpRequested) {
      yield* _mapOtpRequestedToState();
    } else if (event is LoggedIn) {
      yield* _mapLoggedInToState();
    } else if (event is LoggedOut) {
      yield* _mapLoggedOutToState();
    }
  }

  Stream<AuthState> _mapAppLaunchedToState() async* {
    try {
      final isSignedIn = await authProvider.isLoggedIn();

      if (isSignedIn) {
        final name = userProvider.firebaseUser;
        yield Authenticated(name);
      } else {
        yield Unauthenticated();
      }
    } catch (_) {
      yield Unauthenticated();
    }
  }

  Stream<AuthState> _mapOtpRequestedTostate() async* {
    yield AuthInProgress();
    try {
      FirebaseUser firebaseUser = await authProvider.verifyPhone();

      if (firebaseUser != null) {
        yield Authenticated(firebaseUser);
      } else {
        yield Unauthenticated();
      }
    } catch(_, stacktrace) {
      yield Unauthenticated();
    }
  }

  Stream<AuthState> _mapLoggedInToState() async* {
    yield Authenticated(userProvider.firebaseUser);
  }

  Stream<AuthState> _mapLoggedOutToState() async* {
    yield Unauthenticated();
    authProvider.signOutUser();
  }
}

Это AuthProvider

class AuthProvider extends BaseAuthProvider {
  String _verificationId;
  FirebaseUser user;
  final FirebaseAuth _firebaseAuth;

  AuthProvider(
      {FirebaseAuth firebaseAuth})
      : _firebaseAuth = firebaseAuth ?? FirebaseAuth.instance;

  @override
  Future<FirebaseUser> verifyPhone() async {
    final PhoneVerificationCompleted verificationCompleted =
        (AuthCredential phoneAuthCredential) async {
          user = (await _firebaseAuth.signInWithCredential(phoneAuthCredential)).user;
    };

    final PhoneVerificationFailed verificationFailed =
        (AuthException authException) {
      print(
          'Phone number verification failed. Code: ${authException.code}. Message: ${authException.message}');
    };

    final PhoneCodeSent codeSent =
        (String verificationId, [int forceResendingToken]) async {
      _verificationId = verificationId;
    };

    final PhoneCodeAutoRetrievalTimeout codeAutoRetrievalTimeout =
        (String verificationId) {
      _verificationId = verificationId;
    };

    await _firebaseAuth.verifyPhoneNumber(
        phoneNumber: _phoneNumberProvider.number,
        timeout: const Duration(seconds: 5),
        verificationCompleted: verificationCompleted,
        verificationFailed: verificationFailed,
        codeSent: codeSent,
        codeAutoRetrievalTimeout: codeAutoRetrievalTimeout);

    return user;
  }

  Future<FirebaseUser> signInWithPhone() async {
    final AuthCredential credential = PhoneAuthProvider.getCredential(
      verificationId: _verificationId,
      smsCode: _otpProvider.number,
    );
    final FirebaseUser user =
        (await _firebaseAuth.signInWithCredential(credential)).user;
    final FirebaseUser currentUser = await _firebaseAuth.currentUser();
    assert(user.uid == currentUser.uid);

    if (user != null) {
      return currentUser;
    } else {
      return null;
    }
  }

  @override
  Future<void> signOutUser() async {
    return Future.wait([_firebaseAuth.signOut()]); // terminate the session
  }

  @override
  Future<FirebaseUser> getCurrentUser() async {
    return await _firebaseAuth.currentUser(); //retrieve the current user
  }

  @override
  Future<bool> isLoggedIn() async {
    final user =
        await _firebaseAuth.currentUser(); //check if user is logged in or not
    return user != null;
  }

  @override
  void dispose() {}
}

Когда вызывается verifyPhone из AuthBloc, он выполняется асинхронно и, в свою очередь, вызывает mcallbacks, которые снова являются асинхронными. Таким образом, _mapOtpRequestedToState() будет завершено до того, как мы вернем FirebaseUser из AuthProvider. Следовательно, состояние аутентификации не передается, и пользователь не входит в систему.

Нужна помощь!!!