Refactor

lib/core/model/failures.dart

@@ -0,0 +1,73 @@
+import 'package:dio/dio.dart';
+import 'package:hiddify/core/localization/translations.dart';
+
+typedef PresentableError = ({String type, String? message});
+
+mixin Failure {
+  ({String type, String? message}) present(TranslationsEn t);
+}
+
+/// failures that are not expected to happen but depending on [error] type might not be relevant (eg network errors)
+mixin UnexpectedFailure {
+  Object? get error;
+  StackTrace? get stackTrace;
+}
+
+/// failures that are expected to happen and should be handled by the app
+/// and should be logged, eg missing permissions
+mixin ExpectedMeasuredFailure {}
+
+/// failures ignored by analytics service etc.
+mixin ExpectedFailure {}
+
+extension ErrorPresenter on TranslationsEn {
+  PresentableError errorToPair(Object error) => switch (error) {
+        UnexpectedFailure(error: final nestedErr?) => errorToPair(nestedErr),
+        Failure() => error.present(this),
+        DioException() => error.present(this),
+        _ => (type: failure.unexpected, message: null),
+      };
+
+  PresentableError presentError(
+    Object error, {
+    String? action,
+  }) {
+    final pair = errorToPair(error);
+    if (action == null) return pair;
+    return (
+      type: action,
+      message: pair.type + (pair.message == null ? "" : "\n${pair.message!}"),
+    );
+  }
+
+  String presentShortError(
+    Object error, {
+    String? action,
+  }) {
+    final pair = errorToPair(error);
+    if (action == null) return pair.type;
+    return "$action: ${pair.type}";
+  }
+}
+
+extension DioExceptionPresenter on DioException {
+  PresentableError present(TranslationsEn t) => switch (type) {
+        DioExceptionType.connectionTimeout ||
+        DioExceptionType.sendTimeout ||
+        DioExceptionType.receiveTimeout =>
+          (type: t.failure.connection.timeout, message: null),
+        DioExceptionType.badCertificate => (
+            type: t.failure.connection.badCertificate,
+            message: message,
+          ),
+        DioExceptionType.badResponse => (
+            type: t.failure.connection.badResponse,
+            message: message,
+          ),
+        DioExceptionType.connectionError => (
+            type: t.failure.connection.connectionError,
+            message: message,
+          ),
+        _ => (type: t.failure.connection.unexpected, message: message),
+      };
+}