Grade editing

app/lib/grades/grades_service/grades_service.dart

@@ -278,6 +278,16 @@ class GradeRef {
     return this;
   }
 
+  // TODO: Test this seperately / make sure if not existing does not throw
+  GradeResult? get() {
+    return _service.terms.value
+        .firstWhere((term) => term.id == termRef.id)
+        .subjects
+        .firstWhere((subject) => subject.id == subjectRef.id)
+        .grades
+        .firstWhere((grade) => grade.id == id);
+  }
+
   void changeWeight(Weight weight) {
     _service.changeGradeWeight(id: id, termId: termRef.id, weight: weight);
   }

app/lib/grades/pages/grades_details_page/grade_details_page.dart

@@ -12,6 +12,7 @@ import 'package:sharezone/grades/models/grade_id.dart';
 import 'package:sharezone/grades/pages/grades_details_page/grade_details_page_controller.dart';
 import 'package:sharezone/grades/pages/grades_details_page/grade_details_page_controller_factory.dart';
 import 'package:sharezone/grades/pages/grades_details_page/grade_details_view.dart';
+import 'package:sharezone/grades/pages/grades_dialog/grades_dialog.dart';
 import 'package:sharezone/grades/pages/shared/saved_grade_icons.dart';
 import 'package:sharezone/support/support_page.dart';
 import 'package:sharezone_widgets/sharezone_widgets.dart';
@@ -109,23 +110,14 @@ class _EditIconButton extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return IconButton(
+      key: const Key('edit-grade-icon-button'),
       tooltip: 'Note bearbeiten',
-      onPressed: () {
-        showDialog(
-          context: context,
-          builder: (context) {
-            return AlertDialog(
-              title: const Text('Note bearbeiten'),
-              content: const Text(
-                'Das Bearbeiten einer Note ist aktuell noch nicht möglich. Bitte lösche die Note und erstelle sie neu.',
-              ),
-              actions: [
-                TextButton(
-                  child: const Text('OK'),
-                  onPressed: () => Navigator.pop(context),
-                ),
-              ],
-            );
+      onPressed: () async {
+        await Navigator.pushNamed(
+          context,
+          GradesDialog.tag,
+          arguments: {
+            'gradeId': context.read<GradeDetailsPageController>().id.value,
           },
         );
       },

app/lib/grades/pages/grades_dialog/grades_dialog.dart

@@ -30,10 +30,13 @@ import 'package:sharezone_widgets/sharezone_widgets.dart';
 part 'fields.dart';
 
 class GradesDialog extends StatelessWidget {
-  const GradesDialog({super.key});
+  const GradesDialog({super.key, this.gradeId});
 
   static const tag = 'grades-dialog';
 
+  /// The [GradeId] of the grade to edit, `null` if grade should be created.
+  final GradeId? gradeId;
+
   @override
   Widget build(BuildContext context) {
     return ChangeNotifierProvider<GradesDialogController>(

app/lib/grades/pages/grades_dialog/grades_dialog_controller.dart

@@ -22,6 +22,7 @@ import 'package:sharezone/grades/grades_service/grades_service.dart';
 import 'grades_dialog_view.dart';
 
 class GradesDialogController extends ChangeNotifier {
+  final GradeId? gradeId;
   final Stream<List<Course>> coursesStream;
   final GradesService gradesService;
   final CrashAnalytics crashAnalytics;
@@ -139,19 +140,44 @@ class GradesDialogController extends ChangeNotifier {
     required this.coursesStream,
     required this.crashAnalytics,
     required this.analytics,
+    this.gradeId,
   }) {
-    _selectedTermId = _getActiveTermId();
-    _gradingSystemOfSelectedTerm = _getGradingSystemOfTerm(_selectedTermId);
-    _gradingSystem =
-        _gradingSystemOfSelectedTerm ?? GradingSystem.oneToSixWithPlusAndMinus;
-    _date = Date.today();
-    _gradeType = GradeType.writtenExam;
-    _title = _gradeType.predefinedType?.toUiString();
-    _takeIntoAccount = true;
+    if (gradeId != null) {
+      final gradeRef = gradesService.grade(gradeId!);
+      final grade = gradeRef.get()!;
+      final subjectOfGrade = gradesService.getSubject(gradeRef.subjectRef.id)!;
+      _grade =
+          grade.value.displayableGrade ??
+          grade.value.asNum.toString().replaceAll('.', ',');
+      _title = grade.title;
+
+      _selectedTermId = _getActiveTermId();
+      _gradingSystemOfSelectedTerm = _getGradingSystemOfTerm(_selectedTermId);
+      _gradingSystem = grade.gradingSystem;
+      _selectSubjectId = subjectOfGrade.id;
+      _date = grade.date;
+      _gradeType = gradesService.getPossibleGradeTypes().firstWhere(
+        (gt) => gt.id == grade.gradeTypeId,
+      );
+      _takeIntoAccount = grade.isTakenIntoAccount;
+      _subjects = gradesService.getSubjects();
+      _detailsController = TextEditingController(text: grade.details);
+    } else {
+      _selectedTermId = _getActiveTermId();
+      _gradingSystemOfSelectedTerm = _getGradingSystemOfTerm(_selectedTermId);
+      _gradingSystem =
+          _gradingSystemOfSelectedTerm ??
+          GradingSystem.oneToSixWithPlusAndMinus;
+      _date = Date.today();
+      _gradeType = GradeType.writtenExam;
+      _title = _gradeType.predefinedType?.toUiString();
+      _takeIntoAccount = true;
+      _subjects = gradesService.getSubjects();
+      _detailsController = TextEditingController();
+    }
+
     _titleController = TextEditingController(text: _title);
-    _subjects = gradesService.getSubjects();
-    _gradeFieldController = TextEditingController();
-    _detailsController = TextEditingController();
+    _gradeFieldController = TextEditingController(text: _grade);
 
     // Even though the fields are not filled at the beginning, we don't want to
     // show any error messages. The user should see the error messages only

app/lib/main/sharezone_app.dart

@@ -64,6 +64,7 @@ import 'package:sharezone/util/navigation_service.dart';
 import 'package:sharezone_common/references.dart';
 import 'package:showcaseview/showcaseview.dart';
 
+import '../grades/grades_service/grades_service.dart';
 import 'missing_account_information_guard/missing_account_information_guard.dart';
 import 'onboarding/onboarding_listener.dart';
 
@@ -209,7 +210,14 @@ class _SharezoneAppState extends State<SharezoneApp>
                 ICalLinksPage.tag: (context) => const ICalLinksPage(),
                 ICalLinksDialog.tag: (context) => const ICalLinksDialog(),
                 CreateTermPage.tag: (context) => const CreateTermPage(),
-                GradesDialog.tag: (context) => const GradesDialog(),
+                GradesDialog.tag: (context) {
+                  if (ModalRoute.of(context)!.settings.arguments case {
+                    'gradeId': String id,
+                  }) {
+                    return GradesDialog(gradeId: GradeId(id));
+                  }
+                  return const GradesDialog();
+                },
                 LanguagePage.tag: (context) => const LanguagePage(),
               },
               navigatorKey: navigationService.navigatorKey,

app/test/grades/pages/grade_details_page/grade_details_page_test.dart

@@ -11,17 +11,21 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/annotations.dart';
 import 'package:mockito/mockito.dart';
 import 'package:provider/provider.dart';
-import 'package:sharezone/grades/models/grade_id.dart';
+import 'package:sharezone/grades/grades_service/grades_service.dart';
 import 'package:sharezone/grades/pages/grades_details_page/grade_details_page.dart';
 import 'package:sharezone/grades/pages/grades_details_page/grade_details_page_controller.dart';
 import 'package:sharezone/grades/pages/grades_details_page/grade_details_page_controller_factory.dart';
 import 'package:sharezone/grades/pages/grades_details_page/grade_details_view.dart';
+import 'package:sharezone/grades/pages/grades_dialog/grades_dialog.dart';
+import 'package:sharezone/grades/pages/grades_dialog/grades_dialog_controller_factory.dart';
 
+import '../grades_dialog/grades_dialog_controller_test.dart';
 import 'grade_details_page_test.mocks.dart';
 
 @GenerateNiceMocks([
   MockSpec<GradeDetailsPageController>(),
   MockSpec<GradeDetailsPageControllerFactory>(),
+  MockSpec<GradesDialogControllerFactory>(),
 ])
 void main() {
   const id = GradeId('1');
@@ -56,29 +60,66 @@ void main() {
   setUp(() {
     controllerFactory = MockGradeDetailsPageControllerFactory();
     controller = MockGradeDetailsPageController();
+    when(controller.id).thenReturn(id);
     when(controllerFactory.create(id)).thenReturn(controller);
     setLoaded();
   });
 
   group(GradeDetailsPage, () {
     Future<void> pushGradeDetailsPage(WidgetTester tester) async {
       await tester.pumpWidget(
-        MaterialApp(
-          home: MultiProvider(
-            providers: [
-              Provider<GradeDetailsPageControllerFactory>.value(
-                value: controllerFactory,
+        MultiProvider(
+          providers: [
+            Provider<GradeDetailsPageControllerFactory>.value(
+              value: controllerFactory,
+            ),
+            ChangeNotifierProvider<GradeDetailsPageController>(
+              create: (context) => controller,
+            ),
+            Provider<GradesDialogControllerFactory>.value(
+              value: GradesDialogControllerFactory(
+                analytics: MockAnalytics(),
+                coursesStream: () => Stream.empty(),
+                gradesService: GradesService(),
+                crashAnalytics: MockCrashAnalytics(),
               ),
-              ChangeNotifierProvider<GradeDetailsPageController>(
-                create: (context) => controller,
-              ),
-            ],
-            child: const GradeDetailsPage(id: id),
+            ),
+          ],
+          child: MaterialApp(
+            routes: {
+              GradesDialog.tag: (context) {
+                if (ModalRoute.of(context)!.settings.arguments case {
+                  'gradeId': String id,
+                }) {
+                  return GradesDialog(gradeId: GradeId(id));
+                }
+                return const GradesDialog();
+              },
+            },
+            home: const GradeDetailsPage(id: id),
           ),
         ),
       );
     }
 
+    testWidgets(
+      'should show grades editing dialog with selected grade when edit icon is tapped',
+      (tester) async {
+        await pushGradeDetailsPage(tester);
+
+        await tester.tap(find.byKey(const Key('edit-grade-icon-button')));
+        await tester.pumpAndSettle();
+
+        expect(find.byType(GradesDialog), findsOneWidget);
+        expect(
+          find.byWidgetPredicate(
+            (widget) => widget is GradesDialog && widget.gradeId == id,
+          ),
+          findsOneWidget,
+        );
+      },
+    );
+
     testWidgets('should delete grade when confirmed', (tester) async {
       await pushGradeDetailsPage(tester);