initialized Application theme

lib/services/api/network_exception.dart

@@ -0,0 +1,64 @@
+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 ApiServer.");
+      case DioExceptionType.sendTimeout:
+        return ServerFailure("Send timeout with ApiServer.");
+
+      case DioExceptionType.receiveTimeout:
+        return ServerFailure("Receive timeout with ApiServer.");
+
+      case DioExceptionType.badCertificate:
+        return ServerFailure("Bad certificate!");
+
+      case DioExceptionType.badResponse:
+        return ServerFailure.fromResponse(
+            dioError.response!.statusCode!, dioError.response!.data);
+      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!");
+    }
+  }
+
+  factory ServerFailure.fromResponse(int statusCode, dynamic response) {
+    if (statusCode == 400 || statusCode == 401 || statusCode == 403) {
+      return ServerFailure(response);
+    } 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;
+  }
+}