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/budget.dart';

final budgetApiProvider = Provider<BudgetApi>((ref) => BudgetApi(ref.watch(dioProvider)));

/// 预算接口（后端只提供当月预算）
class BudgetApi {
  final Dio _dio;

  BudgetApi(this._dio);

  /// 获取当月预算。
  ///
  /// 未设置预算时后端可能返回 204 / 空 body，此时返回 [BudgetInfo.empty]
  /// 而不是抛错——否则首页会因为"没设预算"而进入错误态。
  Future<BudgetInfo> getBudget() async {
    try {
      final res = await _dio.get('/budgets');
      return _parse(res.data);
    } on DioException catch (e) {
      final err = e.error;
      throw err is ApiException ? err : ApiException(-1, '预算加载失败');
    }
  }

  /// 设置/修改当月预算（每月生效，可随时修改）。
  /// 后端自动填充年月，amount 必须 >= 0。
  Future<BudgetInfo> setCurrentBudget(double amount) async {
    try {
      final res = await _dio.put('/budgets/current', data: {'amount': amount});
      return _parse(res.data);
    } on DioException catch (e) {
      final err = e.error;
      throw err is ApiException ? err : ApiException(-1, '预算保存失败');
    }
  }

  BudgetInfo _parse(Object? data) {
    if (data == null) return BudgetInfo.empty;
    if (data is Map<String, dynamic>) return BudgetInfo.fromJson(data);
    if (data is Map && data['data'] is Map) {
      return BudgetInfo.fromJson(Map<String, dynamic>.from(data['data'] as Map));
    }
    return BudgetInfo.empty;
  }
}