import 'package:dio/dio.dart';

import '../config/api_config.dart';
import '../models/models.dart';

class ApiException implements Exception {
  ApiException(this.message, {this.statusCode});

  final String message;
  final int? statusCode;

  @override
  String toString() => message;
}

class ApiClient {
  ApiClient() {
    dio = Dio(
      BaseOptions(
        baseUrl: resolveApiBaseUrl(),
        connectTimeout: const Duration(seconds: 15),
        receiveTimeout: const Duration(seconds: 15),
        headers: const {
          'Content-Type': 'application/json',
          'Accept': 'application/json',
        },
      ),
    );
    dio.interceptors.add(
      InterceptorsWrapper(
        onRequest: (options, handler) {
          if (token != null && token!.isNotEmpty) {
            options.headers['Authorization'] = 'Bearer $token';
          }
          handler.next(options);
        },
      ),
    );
  }

  late final Dio dio;
  String? token;

  Future<({String token, AppUser user})> staffLogin(String phone, String password) {
    return _send(
      dio.post('/auth/staff-login', data: {'phone': phone, 'password': password}),
      (data) {
        final map = data as Map<String, dynamic>;
        return (
          token: map['token'] as String,
          user: AppUser.fromJson(map['user'] as Map<String, dynamic>),
        );
      },
    );
  }

  Future<({String requestId, String secret})> dealerLogin(String phone) {
    return _send(dio.post('/auth/dealer-login', data: {'phone': phone}), (data) {
      final map = data as Map<String, dynamic>;
      return (requestId: map['requestId'] as String, secret: map['secret'] as String);
    });
  }

  Future<DealerLoginStatus> dealerLoginStatus(String requestId, String secret) {
    return _send(
      dio.get('/auth/dealer-login/$requestId', queryParameters: {'secret': secret}),
      (data) => DealerLoginStatus.fromJson(data as Map<String, dynamic>),
    );
  }

  Future<List<LoginRequestItem>> loginRequests() {
    return _send(dio.get('/auth/login-requests'), (data) => _list(data, LoginRequestItem.fromJson));
  }

  Future<void> approveLogin(String id) {
    return _send(dio.post('/auth/login-requests/$id/approve'), (_) {});
  }

  Future<void> rejectLogin(String id) {
    return _send(dio.post('/auth/login-requests/$id/reject'), (_) {});
  }

  Future<AppUser> me() {
    return _send(
      dio.get('/auth/me'),
      (data) => AppUser.fromJson(data as Map<String, dynamic>),
    );
  }

  Future<List<Dealer>> dealers() {
    return _send(dio.get('/dealers'), (data) => _list(data, Dealer.fromJson));
  }

  Future<List<StockItem>> stocks({String? dealerId}) {
    return _send(
      dio.get(
        '/stocks',
        queryParameters: {
          if (dealerId != null && dealerId.isNotEmpty) 'dealerId': dealerId,
        },
      ),
      (data) => _list(data, StockItem.fromJson),
    );
  }

  Future<StockItem> createStock(Map<String, dynamic> body) {
    return _send(
      dio.post('/stocks', data: body),
      (data) => StockItem.fromJson((data as Map<String, dynamic>)['data'] as Map<String, dynamic>),
    );
  }

  Future<StockItem> updateStage(String chassisNumber, Map<String, dynamic> body) {
    return _send(
      dio.patch('/stocks/$chassisNumber/stage', data: body),
      (data) => StockItem.fromJson((data as Map<String, dynamic>)['data'] as Map<String, dynamic>),
    );
  }

  Future<StockItem> transferStock(String chassisNumber, String dealerId) {
    return _send(
      dio.post('/stocks/$chassisNumber/transfer', data: {'dealerId': dealerId}),
      (data) => StockItem.fromJson((data as Map<String, dynamic>)['data'] as Map<String, dynamic>),
    );
  }

  Future<List<EventPlan>> events({String? dealerId, String? planType}) {
    return _send(
      dio.get(
        '/events',
        queryParameters: {
          if (dealerId != null && dealerId.isNotEmpty) 'dealerId': dealerId,
          if (planType != null && planType.isNotEmpty) 'planType': planType,
        },
      ),
      (data) => _list(data, EventPlan.fromJson),
    );
  }

  Future<EventPlan> createEvent(Map<String, dynamic> body) {
    return _send(
      dio.post('/events', data: body),
      (data) => EventPlan.fromJson((data as Map<String, dynamic>)['data'] as Map<String, dynamic>),
    );
  }

  Future<List<ServicePoint>> servicePoints({String? district, String? search}) {
    return _send(
      dio.get(
        '/service-points',
        queryParameters: {
          if (district != null && district.isNotEmpty) 'district': district,
          if (search != null && search.isNotEmpty) 'search': search,
        },
      ),
      (data) => _list(data, ServicePoint.fromJson),
    );
  }

  Future<ServicePoint> createServicePoint(Map<String, dynamic> body) {
    return _send(
      dio.post('/service-points', data: body),
      (data) => ServicePoint.fromJson((data as Map<String, dynamic>)['data'] as Map<String, dynamic>),
    );
  }

  Future<Dealer> createDealer(Map<String, dynamic> body) {
    return _send(
      dio.post('/admin/dealers', data: body),
      (data) => Dealer.fromJson((data as Map<String, dynamic>)['data'] as Map<String, dynamic>),
    );
  }

  Future<void> deleteDealer(String id) {
    return _send(dio.delete('/admin/dealers/$id'), (_) {});
  }

  Future<List<Dealer>> adminDealers() {
    return _send(dio.get('/admin/dealers'), (data) => _list(data, Dealer.fromJson));
  }

  Future<List<AppUser>> salesReps() {
    return _send(dio.get('/admin/sales-reps'), (data) => _list(data, AppUser.fromJson));
  }

  Future<AppUser> createSalesRep(Map<String, dynamic> body) {
    return _send(
      dio.post('/admin/sales-reps', data: body),
      (data) => AppUser.fromJson((data as Map<String, dynamic>)['data'] as Map<String, dynamic>),
    );
  }

  Future<AppUser> assignDealer({
    required String salesRepId,
    required String dealerId,
    required bool assigned,
  }) {
    return _send(
      dio.patch(
        '/admin/assign-dealer',
        data: {
          'salesRepId': salesRepId,
          'dealerId': dealerId,
          'assigned': assigned,
        },
      ),
      (data) => AppUser.fromJson((data as Map<String, dynamic>)['data'] as Map<String, dynamic>),
    );
  }

  Future<T> _send<T>(Future<Response<dynamic>> request, T Function(dynamic data) parse) async {
    try {
      final response = await request;
      return parse(response.data);
    } on DioException catch (error) {
      final data = error.response?.data;
      final message = data is Map && data['message'] is String
          ? data['message'] as String
          : 'Network request failed';
      throw ApiException(message, statusCode: error.response?.statusCode);
    }
  }

  List<T> _list<T>(dynamic data, T Function(Map<String, dynamic>) parse) {
    final raw = (data as Map<String, dynamic>)['data'] as List<dynamic>;
    return raw.map((item) => parse(item as Map<String, dynamic>)).toList();
  }
}