syncrow-app/lib/services/api/network_exception.dart

import 'package:dio/dio.dart';

abstract class Failure {
  final String errMessage;

  Failure(this.errMessage);
}

class ServerFailure extends Failure {
  ServerFailure(super.errMessage);

  @override
  String toString() {
    return errMessage;
  }

  factory ServerFailure.fromDioError(DioException dioError) {
    switch (dioError.type) {
      case DioExceptionType.connectionTimeout:
        return ServerFailure("Connection timeout with the Server.");
      case DioExceptionType.sendTimeout:
        return ServerFailure("Send timeout with the Server.");

      case DioExceptionType.receiveTimeout:
        return ServerFailure("Receive timeout with the Server.");

      case DioExceptionType.badCertificate:
        return ServerFailure("Bad certificate!");

      case DioExceptionType.badResponse:
        {
          // var document = parser.parse(dioError.response!.data.toString());
          // var message = document.body!.text;
          return ServerFailure.fromResponse(dioError.response!.statusCode!,
              dioError.response!.data['message'].toString()
              // message
              );
        }
      case DioExceptionType.cancel:
        return ServerFailure("The request to ApiServer was canceled");

      case DioExceptionType.connectionError:
        return ServerFailure("No Internet Connection");

      case DioExceptionType.unknown:
        return ServerFailure("Unexpected Error, Please try again!");

      default:
        return ServerFailure("Unexpected Error, Please try again!");
    }
  }

  factory ServerFailure.fromResponse(int statusCode, dynamic response) {
    if (statusCode == 401 || statusCode == 403) {
      return ServerFailure(response);
    } else if (statusCode == 400) {
      //response is list of errors
      List<String> errors = [];
      response.forEach((element) {
        errors.add(element);
      });
      return ServerFailure(errors.join('\n'));
    } else if (statusCode == 404) {
      return ServerFailure("Your request not found, Please try later!");
    } else if (statusCode == 500) {
      return ServerFailure(response);
    } else {
      return ServerFailure("Opps there was an Error, Please try again!");
    }
  }
}

class ResponseFailure extends Failure {
  ResponseFailure(super.errMessage);

  @override
  String toString() {
    return errMessage;
  }
}