fix dimmed safearea and translate error messages

mobile/lib/main.dart

@@ -19,6 +19,9 @@ import 'package:mobile/controllers/routing.dart';
 
 void main() {
   WidgetsFlutterBinding.ensureInitialized();
+
+  ErrorMessages.init("danish");
+
   final server = BackendServer();
   final usersController = UsersController(server: server);
   final sessionController = SessionController(server: server);

mobile/lib/pages/finish_shopping_page.dart

@@ -3,6 +3,7 @@ import 'package:mobile/controllers/routing.dart';
 import 'package:mobile/controllers/cart.dart';
 import 'package:mobile/controllers/paying_state.dart';
 import 'package:mobile/results.dart';
+import 'package:mobile/server/server.dart';
 import 'package:mobile/utils/price.dart';
 import 'package:mobile/widgets/primary_button.dart';
 import 'package:mobile/widgets/receipt_item.dart';
@@ -20,10 +21,10 @@ class FinishShoppingPage extends StatelessWidget {
     final cart = cartController.allCartItems();
 
     return Scaffold(
-      body: SafeArea(
-        child: Stack(
+      body: Stack(
         children: [
-            Column(
+          SafeArea(
+            child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
                 const BackButton(),
@@ -57,14 +58,13 @@ class FinishShoppingPage extends StatelessWidget {
                             payingStateRepo.next();
                             await Future.delayed(const Duration(seconds: 1));
                             if (await cartController.purchase()
-                                is Err<Null, String>) {
+                                case Err<Null, String>(value: final message)) {
                               if (context.mounted) {
                                 showDialog<String>(
                                   context: context,
                                   builder: (BuildContext context) =>
                                       AlertDialog(
-                                    content: const Text(
-                                        'Du har desværre ikke råd til at købe dette'),
+                                    content: Text(ErrorMessages.fancy(message)),
                                     actions: <Widget>[
                                       TextButton(
                                         onPressed: () =>
@@ -93,6 +93,7 @@ class FinishShoppingPage extends StatelessWidget {
                 ),
               ],
             ),
+          ),
           if (payingStateRepo.state != PayingState.unset) ...[
             Container(
               color: Colors.black.withValues(alpha: 0.5),
@@ -142,7 +143,6 @@ class FinishShoppingPage extends StatelessWidget {
           )
         ],
       ),
-      ),
     );
   }
 }

mobile/lib/server/server.dart

@@ -1,3 +1,4 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:mobile/models/cart_item.dart';
 import 'package:mobile/models/product.dart';
@@ -32,3 +33,62 @@ abstract class Server {
 
   Image productImage(int productId);
 }
+
+class ErrorMessages {
+  final String language;
+
+  static ErrorMessages? _instance;
+
+  static init(String language) {
+    _instance = ErrorMessages(language: language);
+  }
+
+  static ErrorMessages get instance {
+    final instance = _instance;
+    if (instance == null) {
+      throw NotInitialized();
+    }
+    return instance;
+  }
+
+  ErrorMessages({required this.language});
+
+  static String fancy(String message) {
+    return instance._fancy(message);
+  }
+
+  String _fancy(String message) {
+    switch (language) {
+      case "danish":
+        return _fancyDanish(message);
+      default:
+        return "error: $message";
+    }
+  }
+
+  String _fancyDanish(String message) {
+    switch (message) {
+      case "insufficient funds":
+        return "Du har desværre ikke nok penge på kontoen.";
+
+      default:
+        if (kDebugMode) {
+          throw NotTranslated(message: message);
+        }
+        return "error: $message";
+    }
+  }
+}
+
+class NotInitialized implements Exception {}
+
+class NotTranslated implements Exception {
+  final String message;
+
+  NotTranslated({required this.message});
+
+  @override
+  String toString() {
+    return "${super.toString()}: message \"$message\" is not translated";
+  }
+}