import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:http/http.dart' as http;
import 'models/weather_models.dart';
import 'repositories/weather_repository.dart';
import 'services/wallpaper_service.dart';
import 'providers/city_provider.dart';

// 仓库 Provider
final weatherRepositoryProvider = Provider<WeatherRepository>((ref) {
  return WeatherRepository(client: http.Client());
});

// 天气状态 Notifier
final weatherProvider = AsyncNotifierProvider<WeatherNotifier, WeatherModel>(
  () {
    return WeatherNotifier();
  },
);

class WeatherNotifier extends AsyncNotifier<WeatherModel> {
  @override
  Future<WeatherModel> build() async {
    // 从城市管理获取当前城市
    final cityListNotifier = ref.read(cityListProvider.notifier);
    final currentCity = await cityListNotifier.getCurrentCity();

    // 监听当前城市变化
    ref.listen(currentCityProvider, (previous, next) {
      next.whenData((city) {
        if (previous?.value != city) {
          refetchWeather(city);
        }
      });
    });

    return _fetchWeather(currentCity);
  }

  Future<WeatherModel> _fetchWeather(String city) async {
    final repository = ref.read(weatherRepositoryProvider);
    return await repository.fetchWeather(city);
  }

  Future<void> refetchWeather(String city) async {
    state = const AsyncValue.loading();
    try {
      final weather = await _fetchWeather(city);
      state = AsyncValue.data(weather);
    } catch (e, s) {
      state = AsyncValue.error(e, s);
    }
  }

  // 切换城市并刷新天气
  Future<void> switchCity(String city) async {
    final cityListNotifier = ref.read(cityListProvider.notifier);
    await cityListNotifier.setCurrentCity(city);
    await refetchWeather(city);
  }
}

// 壁纸服务 Provider
final wallpaperServiceProvider = Provider<WallpaperService>((ref) {
  return WallpaperService();
});

// 动态壁纸路径 Provider
final dynamicWallpaperProvider = Provider<String>((ref) {
  final weatherAsync = ref.watch(weatherProvider);
  final wallpaperService = ref.watch(wallpaperServiceProvider);
  return weatherAsync.when(
    data: (weather) {
      final code = weather.current.condition.code;
      final isDay = weather.current.isDay == 1;
      return wallpaperService.getWallpaper(code, isDay);
    },
    loading: () => wallpaperService.getWallpaper(1000, true),
    error: (e, s) => wallpaperService.getWallpaper(1000, true),
  );
});