import 'package:flutter/foundation.dart';

import '../../data/repositories/settings_repository.dart';
import 'gps_speed_controller.dart';
import 'weather_controller.dart';

/// Persisted Home visibility and source choices for speed and temperature.
///
/// OBD-II is preferred when it is connected and fresh; GPS and the weather
/// provider are the fallbacks. Turning either row on with a GPS source asks for
/// location permission, and turning temperature off stops the weather poller so
/// CarDash keeps working quietly when the row is hidden.
class TelemetrySettingsController extends ChangeNotifier {
  TelemetrySettingsController(this._settings, this._weather, this._gps);

  final SettingsRepository _settings;
  final WeatherController _weather;
  final GpsSpeedController _gps;

  bool _speedEnabled = true;
  bool _speedUseObd = true;
  bool _temperatureEnabled = false;
  bool _temperatureUseObd = true;
  bool _disposed = false;

  bool get speedEnabled => _speedEnabled;

  bool get speedUseObd => _speedUseObd;

  bool get temperatureEnabled => _temperatureEnabled;

  bool get temperatureUseObd => _temperatureUseObd;

  bool get weatherEnabled => _weather.enabled;

  String? get weatherError => _weather.error;

  void initialize() {
    _speedEnabled = _settings.speedEnabled;
    _speedUseObd = _settings.speedUseObd;
    _temperatureEnabled = _settings.temperatureEnabled;
    _temperatureUseObd = _settings.temperatureUseObd;
    _weather.restoreEnabled(
      _temperatureEnabled && _settings.weatherLocationTemperature,
    );
  }

  /// Returns false when the speed switch is on but GPS fallback permission was
  /// denied and OBD-II is not configured as the source.
  Future<bool> setSpeedEnabled(bool value) async {
    if (value == _speedEnabled) return true;
    _speedEnabled = value;
    _notify();
    await _settings.setSpeedEnabled(value);
    if (!value || !_needsGpsSpeed) return true;
    return _gps.requestPermission();
  }

  Future<bool> setSpeedUseObd(bool value) async {
    if (value == _speedUseObd) return true;
    _speedUseObd = value;
    _notify();
    await _settings.setSpeedUseObd(value);
    if (value || !_speedEnabled || !_needsGpsSpeed) return true;
    return _gps.requestPermission();
  }

  /// GPS is the source whenever the adapter is not configured or OBD speed is
  /// explicitly off. A configured-but-disconnected adapter keeps OBD selected.
  bool get _needsGpsSpeed =>
      !_speedUseObd || _settings.obdAdapterAddress == null;

  /// Returns false when the temperature switch is on but location permission
  /// for the weather fallback was denied. OBD-II temperature can still work.
  Future<bool> setTemperatureEnabled(bool value) async {
    if (value == _temperatureEnabled) return true;
    _temperatureEnabled = value;
    _notify();
    await _settings.setTemperatureEnabled(value);
    if (!value) {
      await _settings.setWeatherLocationTemperature(false);
      await _weather.setEnabled(false);
      return true;
    }
    return _enableWeather();
  }

  Future<bool> setTemperatureUseObd(bool value) async {
    if (value == _temperatureUseObd) return true;
    _temperatureUseObd = value;
    _notify();
    await _settings.setTemperatureUseObd(value);
    if (!value && _temperatureEnabled) {
      return _enableWeather();
    }
    return true;
  }

  Future<bool> _enableWeather() async {
    final granted = await _weather.setEnabled(true);
    if (granted) {
      await _settings.setWeatherLocationTemperature(true);
    }
    _notify();
    return granted;
  }

  void _notify() {
    if (!_disposed) notifyListeners();
  }

  @override
  void dispose() {
    _disposed = true;
    super.dispose();
  }
}