import 'dart:async';

import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:equatable/equatable.dart';
import 'package:meta/meta.dart';
import 'package:user_repository/user_repository.dart';

part 'authentication_event.dart';
part 'authentication_state.dart';

class AuthenticationBloc
    extends Bloc<AuthenticationEvent, AuthenticationState> {
  final UserRepository userRepository;
  late final StreamSubscription<MyUser?> _userSubscription;

  AuthenticationBloc({required UserRepository myUserRepository})
      : userRepository = myUserRepository,
        super(const AuthenticationState.unknown()) {
    _userSubscription = userRepository.streamUser().listen((authUser) {
      add(AuthenticationUserChanged(authUser));
    });
    on<AuthenticationUserChanged>(_onAuthenticationUserChanged);
    on<AuthenticationLogoutRequested>(_onAuthenticationLogoutRequested);
  }

  void _onAuthenticationUserChanged(
      AuthenticationUserChanged event, Emitter<AuthenticationState> emit) {
    emit(
      event.user != null
          ? AuthenticationState.authenticated(event.user!)
          : const AuthenticationState.unauthenticated(),
    );
  }

  void _onAuthenticationLogoutRequested(AuthenticationLogoutRequested event,
      Emitter<AuthenticationState> emit) async {
    await userRepository.logOut();
    emit(const AuthenticationState.unauthenticated());
  }

  @override
  Future<void> close() {
    _userSubscription.cancel();
    return super.close();
  }
}