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/statistics_response.dart';

final statisticsApiProvider =
    Provider<StatisticsApi>((ref) => StatisticsApi(ref.watch(dioProvider)));

/// 统计接口。
///
/// 注意后端三个接口实际都委托给同一段按日聚合逻辑，区别只在参数：
/// daily 传日期区间，weekly 传周一，monthly 传年月。
class StatisticsApi {
  final Dio _dio;

  StatisticsApi(this._dio);

  /// 按日期区间统计（yyyy-MM-dd）
  Future<StatisticsResponse> getDaily({
    required String startDate,
    required String endDate,
  }) async {
    return _request('/statistics/daily', {
      'startDate': startDate,
      'endDate': endDate,
    });
  }

  /// 按周统计，weekStart 为本周一（后端自行算到周内其余日期）
  Future<StatisticsResponse> getWeekly({required String weekStart}) async {
    return _request('/statistics/weekly', {'weekStart': weekStart});
  }

  /// 按月统计
  Future<StatisticsResponse> getMonthly({required int year, required int month}) async {
    return _request('/statistics/monthly', {'year': year, 'month': month});
  }

  Future<StatisticsResponse> _request(String path, Map<String, dynamic> params) async {
    try {
      final res = await _dio.get(path, queryParameters: params);
      final data = res.data;
      if (data is Map<String, dynamic>) return StatisticsResponse.fromJson(data);
      if (data is Map && data['data'] is Map) {
        return StatisticsResponse.fromJson(Map<String, dynamic>.from(data['data'] as Map));
      }
      // 空响应（无数据）按空统计处理，不视为错误
      return StatisticsResponse.empty;
    } on DioException catch (e) {
      final err = e.error;
      throw err is ApiException ? err : ApiException(-1, '统计加载失败');
    }
  }
}