Service: xarici dünya ilə yeganə təmas nöqtəsi

// ══ lib/data/services/api_client.dart ══ (ortaq nazik qat)
class ApiClient {
  ApiClient({
    required http.Client client,
    required String baseUrl,
    required Future<String?> Function() tokenProvider,
  })  : _client = client,
        _baseUrl = baseUrl,
        _tokenProvider = tokenProvider;

  final http.Client _client;
  final String _baseUrl;
  final Future<String?> Function() _tokenProvider;

  Future<Map<String, dynamic>> getJson(
    String path, {
    Map<String, String>? query,
  }) async {
    final token = await _tokenProvider();
    final response = await _client
        .get(
          Uri.parse('$_baseUrl$path').replace(queryParameters: query),
          headers: {
            'Accept': 'application/json',
            if (token != null) 'Authorization': 'Bearer $token',
          },
        )
        .timeout(const Duration(seconds: 20));

    // Status kodunun TİPLİ exception-a çevrilməsi burada baş verir.
    return switch (response.statusCode) {
      200 || 201 => jsonDecode(response.body) as Map<String, dynamic>,
      401 => throw const UnauthorizedException(),
      403 => throw const ForbiddenException(),
      404 => throw const NotFoundException(),
      >= 500 => throw ServerException(response.statusCode),
      _ => throw ApiException(response.statusCode, response.body),
    };
  }
}

// ══ lib/data/services/order_api_client.dart ══ (bir endpoint qrupu)
class OrderApiClient {
  OrderApiClient({required ApiClient api}) : _api = api;
  final ApiClient _api;

  // Giriş: sadə tiplər. Çıxış: DTO. State: YOXDUR.
  Future<List<OrderDto>> getOrders({int page = 1, int limit = 20}) async {
    final json = await _api.getJson('/v1/orders', query: {
      'page': '$page',
      'limit': '$limit',
    });
    return (json['data'] as List<dynamic>)
        .map((e) => OrderDto.fromJson(e as Map<String, dynamic>))
        .toList();
  }

  Future<OrderDto> getOrder(String id) async =>
      OrderDto.fromJson(await _api.getJson('/v1/orders/$id'));
}