import 'package:dio/dio.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../core/network/api_exception.dart';
import '../core/network/dio_client.dart';
import '../models/health.dart';
import '../models/json_util.dart';

final healthApiProvider =
    Provider<HealthApi>((ref) => HealthApi(ref.watch(dioProvider)));

/// 「强宝健康」接口：体重 / 减重目标 / 饮食 / 食物库
///
/// 后端路径都挂在 /api/health/ 下，dio 的 baseUrl 已含 /api。
class HealthApi {
  final Dio _dio;

  HealthApi(this._dio);

  // ================================================================
  // 体重
  // ================================================================

  /// 记一次体重。同一天再记就是覆盖（后端保证）。
  ///
  /// [note] 不传 = 不改动已有备注；传空串 = 清空。
  Future<void> saveWeight({
    required double weight,
    DateTime? date,
    String? note,
  }) async {
    try {
      await _dio.post('/health/weight', data: {
        'weight': weight,
        if (date != null) 'recordDate': _dateText(date),
        'note': ?note,
      });
    } on DioException catch (e) {
      throw _asApiException(e, '体重保存失败');
    }
  }

  /// 折线图数据。[days] 是时间窗（默认 90 天）。
  Future<WeightChart> weightChart({int days = 90}) async {
    try {
      final res = await _dio.get('/health/weight/chart',
          queryParameters: {'days': days});
      return WeightChart.fromJson(_asMap(res.data));
    } on DioException catch (e) {
      throw _asApiException(e, '体重数据加载失败');
    }
  }

  Future<List<WeightRecordItem>> weightHistory() async {
    try {
      final res = await _dio.get('/health/weight/history');
      return asMapListFrom(res.data).map(WeightRecordItem.fromJson).toList();
    } on DioException catch (e) {
      throw _asApiException(e, '历史记录加载失败');
    }
  }

  Future<void> deleteWeight(int id) async {
    try {
      await _dio.delete('/health/weight/$id');
    } on DioException catch (e) {
      throw _asApiException(e, '删除失败');
    }
  }

  // ================================================================
  // 减重目标
  // ================================================================

  Future<WeightGoal> goal() async {
    try {
      final res = await _dio.get('/health/weight/goal');
      return WeightGoal.fromJson(_asMap(res.data));
    } on DioException catch (e) {
      throw _asApiException(e, '目标加载失败');
    }
  }

  /// 设置目标。会覆盖当前进行中的目标。
  Future<WeightGoal> saveGoal({
    required double startWeight,
    required double targetWeight,
    required DateTime startDate,
    required DateTime targetDate,
  }) async {
    try {
      final res = await _dio.post('/health/weight/goal', data: {
        'startWeight': startWeight,
        'targetWeight': targetWeight,
        'startDate': _dateText(startDate),
        'targetDate': _dateText(targetDate),
      });
      return WeightGoal.fromJson(_asMap(res.data));
    } on DioException catch (e) {
      throw _asApiException(e, '目标保存失败');
    }
  }

  // ================================================================
  // 饮食
  // ================================================================

  /// 某天的饮食明细 + 全天合计
  Future<DietDay> dietDay({DateTime? date}) async {
    try {
      final res = await _dio.get('/health/diet/day', queryParameters: {
        if (date != null) 'date': _dateText(date),
      });
      return DietDay.fromJson(_asMap(res.data));
    } on DioException catch (e) {
      throw _asApiException(e, '饮食记录加载失败');
    }
  }

  /// 今日热量合计（首页卡片用）
  Future<NutritionTotals> todayTotals() async {
    try {
      final res = await _dio.get('/health/diet/today');
      final data = _asMap(res.data);
      // 这个接口只回能量和条数，别的字段是 0
      return NutritionTotals(
        energyKcal: asDouble(data['energyKcal']),
        itemCount: asInt(data['itemCount']),
      );
    } on DioException catch (e) {
      throw _asApiException(e, '今日热量加载失败');
    }
  }

  /// 加一条饮食记录。营养值由服务端算，这里只给食物 + 克数。
  Future<void> addDiet({
    required int foodId,
    required double grams,
    required String mealType,
    DateTime? date,
  }) async {
    try {
      await _dio.post('/health/diet', data: {
        'foodId': foodId,
        'amountGrams': grams,
        'mealType': mealType,
        if (date != null) 'recordDate': _dateText(date),
      });
    } on DioException catch (e) {
      throw _asApiException(e, '添加失败');
    }
  }

  /// 改份量（营养值会跟着重算）
  Future<void> updateDietAmount(int id, double grams) async {
    try {
      await _dio.put('/health/diet/$id', data: {'amountGrams': grams});
    } on DioException catch (e) {
      throw _asApiException(e, '修改失败');
    }
  }

  Future<void> deleteDiet(int id) async {
    try {
      await _dio.delete('/health/diet/$id');
    } on DioException catch (e) {
      throw _asApiException(e, '删除失败');
    }
  }

  // ================================================================
  // 食物库
  // ================================================================

  Future<List<FoodItem>> searchFood(String keyword) async {
    try {
      final res = await _dio.get('/health/food/search',
          queryParameters: {'keyword': keyword});
      return asMapListFrom(res.data).map(FoodItem.fromJson).toList();
    } on DioException catch (e) {
      throw _asApiException(e, '搜索失败');
    }
  }

  /// 分类浏览。[category] 为空时返回一级分类列表，
  /// 传了就返回该分类下的食物 —— 后端按参数切换返回类型。
  Future<List<FoodCategory>> foodCategories() async {
    try {
      final res = await _dio.get('/health/food/browse');
      return asMapListFrom(res.data).map(FoodCategory.fromJson).toList();
    } on DioException catch (e) {
      throw _asApiException(e, '分类加载失败');
    }
  }

  Future<List<FoodItem>> foodByCategory(String category,
      {String? subCategory}) async {
    try {
      final res = await _dio.get('/health/food/browse', queryParameters: {
        'category': category,
        'subCategory': ?subCategory,
      });
      return asMapListFrom(res.data).map(FoodItem.fromJson).toList();
    } on DioException catch (e) {
      throw _asApiException(e, '食物加载失败');
    }
  }

  Future<List<FoodCategory>> foodSubCategories(String category) async {
    try {
      final res = await _dio.get('/health/food/sub-categories',
          queryParameters: {'category': category});
      return asMapListFrom(res.data).map(FoodCategory.fromJson).toList();
    } on DioException catch (e) {
      throw _asApiException(e, '子分类加载失败');
    }
  }

  // ================================================================

  static String _dateText(DateTime date) {
    final m = date.month.toString().padLeft(2, '0');
    final d = date.day.toString().padLeft(2, '0');
    return '${date.year}-$m-$d';
  }

  ApiException _asApiException(DioException e, String fallback) {
    final err = e.error;
    return err is ApiException ? err : ApiException(-1, fallback);
  }

  Map<String, dynamic> _asMap(Object? data) {
    if (data is Map<String, dynamic>) {
      // 饮食接口是 { success, data: {...} } 包了一层
      if (data['data'] is Map) {
        return Map<String, dynamic>.from(data['data'] as Map);
      }
      return data;
    }
    return const {};
  }
}

/// 后端这类接口把数组放在 { success, list: [...] } 里，
/// 直接从 data 上取会拿到 null，这里统一拆一层。
List<Map<String, dynamic>> asMapListFrom(Object? data) {
  if (data is Map) {
    final list = data['list'] ?? data['data'];
    if (list is List) {
      return list.whereType<Map<String, dynamic>>().toList();
    }
  }
  if (data is List) {
    return data.whereType<Map<String, dynamic>>().toList();
  }
  return const [];
}