import 'package:hive_flutter/hive_flutter.dart';
import 'package:lunchpick/domain/entities/weather_info.dart';
import 'package:lunchpick/domain/repositories/weather_repository.dart';

class WeatherRepositoryImpl implements WeatherRepository {
  static const String _boxName = 'weather_cache';
  static const String _keyCachedWeather = 'cached_weather';
  static const String _keyLastUpdateTime = 'last_update_time';
  static const Duration _cacheValidDuration = Duration(hours: 1);

  Future<Box> get _box async => await Hive.openBox(_boxName);

  @override
  Future<WeatherInfo> getCurrentWeather({
    required double latitude,
    required double longitude,
  }) async {
    // TODO: 실제 날씨 API 호출 구현
    // 여기서는 임시로 더미 데이터 반환

    final dummyWeather = WeatherInfo(
      current: WeatherData(temperature: 20, isRainy: false, description: '맑음'),
      nextHour: WeatherData(temperature: 22, isRainy: false, description: '맑음'),
    );

    // 캐시에 저장
    await cacheWeatherInfo(dummyWeather);

    return dummyWeather;
  }

  @override
  Future<WeatherInfo?> getCachedWeather() async {
    final box = await _box;

    // 캐시가 유효한지 확인
    final isValid = await _isCacheValid();
    if (!isValid) {
      return null;
    }

    // 캐시된 데이터 가져오기
    final cachedData = box.get(_keyCachedWeather);
    if (cachedData == null) {
      return null;
    }

    try {
      // 안전한 타입 변환
      if (cachedData is! Map) {
        print(
          'WeatherCache: Invalid data type - expected Map but got ${cachedData.runtimeType}',
        );
        await clearWeatherCache();
        return null;
      }

      final Map<String, dynamic> weatherMap = Map<String, dynamic>.from(
        cachedData,
      );

      // Map 구조 검증
      if (!weatherMap.containsKey('current') ||
          !weatherMap.containsKey('nextHour')) {
        print('WeatherCache: Missing required fields in weather data');
        await clearWeatherCache();
        return null;
      }

      return _weatherInfoFromMap(weatherMap);
    } catch (e) {
      // 캐시 데이터가 손상된 경우
      print('WeatherCache: Error parsing cached weather data: $e');
      await clearWeatherCache();
      return null;
    }
  }

  @override
  Future<void> cacheWeatherInfo(WeatherInfo weatherInfo) async {
    final box = await _box;

    // WeatherInfo를 Map으로 변환하여 저장
    final weatherMap = _weatherInfoToMap(weatherInfo);
    await box.put(_keyCachedWeather, weatherMap);
    await box.put(_keyLastUpdateTime, DateTime.now().toIso8601String());
  }

  @override
  Future<void> clearWeatherCache() async {
    final box = await _box;
    await box.delete(_keyCachedWeather);
    await box.delete(_keyLastUpdateTime);
  }

  @override
  Future<bool> isWeatherUpdateNeeded() async {
    final box = await _box;

    // 캐시된 날씨 정보가 없으면 업데이트 필요
    if (!box.containsKey(_keyCachedWeather)) {
      return true;
    }

    // 캐시가 유효한지 확인
    return !(await _isCacheValid());
  }

  Future<bool> _isCacheValid() async {
    final box = await _box;

    final lastUpdateTimeStr = box.get(_keyLastUpdateTime);
    if (lastUpdateTimeStr == null) {
      return false;
    }

    try {
      // 날짜 파싱 시도
      final lastUpdateTime = DateTime.tryParse(lastUpdateTimeStr);
      if (lastUpdateTime == null) {
        print('WeatherCache: Invalid date format in cache: $lastUpdateTimeStr');
        return false;
      }

      final now = DateTime.now();
      final difference = now.difference(lastUpdateTime);

      return difference < _cacheValidDuration;
    } catch (e) {
      print('WeatherCache: Error checking cache validity: $e');
      return false;
    }
  }

  Map<String, dynamic> _weatherInfoToMap(WeatherInfo weatherInfo) {
    return {
      'current': {
        'temperature': weatherInfo.current.temperature,
        'isRainy': weatherInfo.current.isRainy,
        'description': weatherInfo.current.description,
      },
      'nextHour': {
        'temperature': weatherInfo.nextHour.temperature,
        'isRainy': weatherInfo.nextHour.isRainy,
        'description': weatherInfo.nextHour.description,
      },
    };
  }

  WeatherInfo _weatherInfoFromMap(Map<String, dynamic> map) {
    try {
      // current 필드 검증
      final currentMap = map['current'] as Map<String, dynamic>?;
      if (currentMap == null) {
        throw FormatException('Missing current weather data');
      }

      // nextHour 필드 검증
      final nextHourMap = map['nextHour'] as Map<String, dynamic>?;
      if (nextHourMap == null) {
        throw FormatException('Missing nextHour weather data');
      }

      // 필수 필드 검증 및 기본값 제공
      final currentTemp = currentMap['temperature'] as num? ?? 20;
      final currentRainy = currentMap['isRainy'] as bool? ?? false;
      final currentDesc = currentMap['description'] as String? ?? '알 수 없음';

      final nextTemp = nextHourMap['temperature'] as num? ?? 20;
      final nextRainy = nextHourMap['isRainy'] as bool? ?? false;
      final nextDesc = nextHourMap['description'] as String? ?? '알 수 없음';

      return WeatherInfo(
        current: WeatherData(
          temperature: currentTemp.round(),
          isRainy: currentRainy,
          description: currentDesc,
        ),
        nextHour: WeatherData(
          temperature: nextTemp.round(),
          isRainy: nextRainy,
          description: nextDesc,
        ),
      );
    } catch (e) {
      print('WeatherCache: Error converting map to WeatherInfo: $e');
      print('WeatherCache: Map data: $map');
      rethrow;
    }
  }
}