import 'dart:async';
import 'package:location/location.dart';
import 'package:gps/models/gps_point.dart';
import 'package:gps/utils/gps_persister.dart';
import 'bloc_provider.dart';

// An action which is triggert by the UI
enum GpsBlocAction { toggleRecording, save }

// A state change triggert by the Business Logic
enum GpsBlocState { recording, notRecording }

class GpsBloc implements BlocBase {
  final GpsPersister _persister;
  bool _recording = false;
  GpsPoint _currentLocation = GpsPoint();
  List<GpsPoint> _recordedLocations = [];

  final StreamController<GpsPoint> _gpsOutController =
      StreamController<GpsPoint>.broadcast();
  Stream<GpsPoint> get gpsPoint => _gpsOutController.stream;

  final StreamController<LocationData> _gpsInController =
      StreamController<LocationData>.broadcast();
  StreamSink get gpsIn => _gpsInController.sink;

  final StreamController<GpsBlocState> _stateOutController =
      StreamController<GpsBlocState>.broadcast();
  Stream<GpsBlocState> get stateOut => _stateOutController.stream;

  final StreamController<GpsBlocAction> _actionInController =
      StreamController<GpsBlocAction>.broadcast();
  StreamSink get actionIn => _actionInController.sink;

  GpsBloc(this._persister) {
    _gpsInController.stream.listen(_handleNewPosition);
    _actionInController.stream.listen(_handleActions);
  }

  void _handleNewPosition(LocationData event) {
    _currentLocation = GpsPoint(
        latitude: event.latitude ?? 0.0,
        longitude: event.longitude ?? 0.0,
        accuracy: event.accuracy ?? 0.0,
        speed: event.speed ?? 0.0,
        heading: event.heading ?? 0.0,
        time: event.time ?? 0.0,
        satelliteNumber: event.satelliteNumber ?? 0,
        provider: event.provider ?? "none");
    if (_recording) {
      _recordedLocations.add(_currentLocation);
    }
    _gpsOutController.sink.add(_currentLocation);
  }

  void _handleActions(GpsBlocAction event) {
    switch (event) {
      case GpsBlocAction.toggleRecording:
        _recording = !_recording;
        _stateOutController.sink.add(
            _recording ? GpsBlocState.recording : GpsBlocState.notRecording);
        break;
      case GpsBlocAction.save:
        _persister.save(_recordedLocations);
        _recordedLocations = [];
        break;
    }
  }

  @override
  void dispose() {
    _gpsOutController.close();
    _gpsInController.close();
    _stateOutController.close();
    _actionInController.close();
  }
}