Replace CalendricalEventType with EventType enum. (#1317)

`CalendricalEventType` had subclasses that we never used and also
creating Enums with members wasn't possible back then.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Introduced an `EventType` enum to standardize event types across the
app, including 'meeting' and 'exam'.
- **Refactor**
- Updated various components to use the new `EventType` enum for better
consistency and readability.
	- Removed obsolete methods and enums related to event type handling.
- **Tests**
	- Adjusted tests to align with the new `EventType` enum usage.
- **Chores**
- Code clean-up including import reordering and removing unused code
blocks.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

app/lib/calendrical_events/models/calendrical_event.dart

@@ -13,7 +13,25 @@ import 'package:sharezone/timetable/src/models/lesson.dart';
 import 'package:sharezone/timetable/src/models/lesson_length/lesson_length.dart';
 import 'package:time/time.dart';
 
-import 'calendrical_event_types.dart';
+enum EventType {
+  event('meeting'),
+  exam('exam');
+
+  /// Database key for the event type.
+  final String key;
+
+  const EventType(this.key);
+
+  static EventType fromString(String s) {
+    switch (s) {
+      case 'meeting':
+        return event;
+      case 'exam':
+        return exam;
+    }
+    throw ArgumentError("Couldn't parse $EventType from unkown event type: $s");
+  }
+}
 
 class CalendricalEvent {
   /// The date and time when the event was created.
@@ -25,7 +43,7 @@ class CalendricalEvent {
 
   final String eventID, groupID, authorID;
   final GroupType groupType;
-  final CalendricalEventType eventType;
+  final EventType eventType;
   final Date date;
   final Time startTime, endTime;
   final String title;
@@ -64,7 +82,7 @@ class CalendricalEvent {
       endTime: Time.parse(data['endTime'] as String),
       title: data['title'] as String,
       groupType: GroupType.values.byName(data['groupType'] as String),
-      eventType: getEventTypeFromString(data['eventType'] as String),
+      eventType: EventType.fromString(data['eventType'] as String),
       detail: data['detail'] as String?,
       place: data['place'] as String?,
       sendNotification: (data['sendNotification'] as bool?) ?? false,
@@ -77,7 +95,7 @@ class CalendricalEvent {
       'createdOn': createdOn,
       'groupID': groupID,
       'groupType': groupType.name,
-      'eventType': getEventTypeToString(eventType),
+      'eventType': eventType.key,
       'authorID': authorID,
       'date': date.toDateString,
       'startTime': startTime.time,
@@ -95,7 +113,7 @@ class CalendricalEvent {
     String? groupID,
     String? authorID,
     GroupType? groupType,
-    CalendricalEventType? eventType,
+    EventType? eventType,
     Date? date,
     Time? startTime,
     Time? endTime,

app/lib/calendrical_events/page/past_calendrical_events_page.dart

@@ -15,7 +15,6 @@ import 'package:flutter/material.dart';
 import 'package:group_domain_models/group_domain_models.dart';
 import 'package:provider/provider.dart';
 import 'package:sharezone/calendrical_events/models/calendrical_event.dart';
-import 'package:sharezone/calendrical_events/models/calendrical_event_types.dart';
 import 'package:sharezone/calendrical_events/provider/past_calendrical_events_page_controller.dart';
 import 'package:sharezone/calendrical_events/provider/past_calendrical_events_page_controller_factory.dart';
 import 'package:sharezone/sharezone_plus/page/sharezone_plus_page.dart';
@@ -176,7 +175,7 @@ class _SharezonePlusAd extends StatelessWidget {
         detail: null,
         endTime: Time(hour: 12, minute: 0),
         eventID: 'eventId',
-        eventType: Exam(),
+        eventType: EventType.exam,
         groupType: GroupType.course,
         latestEditor: null,
         place: null,

app/lib/timetable/src/widgets/events/calender_event_card.dart

@@ -8,10 +8,9 @@
 
 import 'package:bloc_provider/bloc_provider.dart';
 import 'package:flutter/material.dart';
-import 'package:sharezone/main/application_bloc.dart';
 import 'package:sharezone/calendrical_events/models/calendrical_event.dart';
-import 'package:sharezone/calendrical_events/models/calendrical_event_types.dart';
 import 'package:sharezone/groups/src/pages/course/course_edit/design/course_edit_design.dart';
+import 'package:sharezone/main/application_bloc.dart';
 import 'package:sharezone/report/page/report_page.dart';
 import 'package:sharezone/report/report_icon.dart';
 import 'package:sharezone/report/report_item.dart';
@@ -112,7 +111,7 @@ Future<void> onEventLongPress(
   final isAuthor = api.uID == event.authorID;
   final hasPermissionsToManageEvents = hasPermissionToManageEvents(
       api.course.getRoleFromCourseNoSync(event.groupID)!, isAuthor);
-  final isExam = event.eventType == Exam();
+  final isExam = event.eventType == EventType.exam;
   final result = await showLongPressAdaptiveDialog<_EventLongPressResult>(
     context: context,
     title: "${isExam ? "Prüfung" : "Termin"}: ${event.title}",

app/lib/timetable/timetable_add_event/src/timetable_add_event_event_dialog_api.dart

@@ -11,10 +11,12 @@ import 'package:date/date.dart';
 import 'package:equatable/equatable.dart';
 import 'package:group_domain_models/group_domain_models.dart';
 import 'package:sharezone/calendrical_events/models/calendrical_event.dart';
-import 'package:sharezone/calendrical_events/models/calendrical_event_types.dart';
 import 'package:sharezone/util/api.dart';
 import 'package:time/time.dart';
 
+export 'package:sharezone/calendrical_events/models/calendrical_event.dart'
+    show EventType;
+
 class EventDialogApi {
   final SharezoneGateway _api;
 
@@ -33,10 +35,7 @@ class EventDialogApi {
       createdOn: null,
       groupID: command.courseId.id,
       groupType: GroupType.course,
-      eventType: switch (command.eventType) {
-        EventType.event => Meeting(),
-        EventType.exam => Exam(),
-      },
+      eventType: command.eventType,
       date: command.date,
       place: command.location,
       startTime: command.startTime,
@@ -52,8 +51,6 @@ class EventDialogApi {
   }
 }
 
-enum EventType { event, exam }
-
 class CreateEventCommand extends Equatable {
   final String title;
   final CourseId courseId;

app/lib/timetable/timetable_edit/event/timetable_event_edit_page.dart

@@ -12,9 +12,8 @@ import 'package:bloc_provider/bloc_provider.dart';
 import 'package:date/date.dart';
 import 'package:flutter/material.dart';
 import 'package:group_domain_models/group_domain_models.dart';
-import 'package:sharezone/main/application_bloc.dart';
 import 'package:sharezone/calendrical_events/models/calendrical_event.dart';
-import 'package:sharezone/calendrical_events/models/calendrical_event_types.dart';
+import 'package:sharezone/main/application_bloc.dart';
 import 'package:sharezone/markdown/markdown_analytics.dart';
 import 'package:sharezone/markdown/markdown_support.dart';
 import 'package:sharezone/timetable/src/edit_date.dart';
@@ -90,7 +89,7 @@ class _TimetableEditEventPage extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final isExam = initialEvent.eventType == Exam();
+    final isExam = initialEvent.eventType == EventType.exam;
     return PopScope(
       canPop: false,
       onPopInvoked: (didPop) async {
@@ -354,7 +353,7 @@ class _DetailField extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final isExam = initialEvent.eventType == Exam();
+    final isExam = initialEvent.eventType == EventType.exam;
     final bloc = BlocProvider.of<TimetableEditEventBloc>(context);
     return Padding(
       padding: const EdgeInsets.only(top: 10),

app/lib/timetable/timetable_page/timetable_event_details.dart

@@ -13,10 +13,10 @@ import 'package:design/design.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_markdown/flutter_markdown.dart';
 import 'package:flutter_native_timezone/flutter_native_timezone.dart';
+import 'package:platform_check/platform_check.dart';
 import 'package:provider/provider.dart';
-import 'package:sharezone/main/application_bloc.dart';
 import 'package:sharezone/calendrical_events/models/calendrical_event.dart';
-import 'package:sharezone/calendrical_events/models/calendrical_event_types.dart';
+import 'package:sharezone/main/application_bloc.dart';
 import 'package:sharezone/report/page/report_page.dart';
 import 'package:sharezone/report/report_icon.dart';
 import 'package:sharezone/report/report_item.dart';
@@ -26,7 +26,6 @@ import 'package:sharezone/timetable/timetable_edit/event/timetable_event_edit_pa
 import 'package:sharezone/timetable/timetable_permissions.dart';
 import 'package:sharezone/util/launch_link.dart';
 import 'package:sharezone/util/navigation_service.dart';
-import 'package:platform_check/platform_check.dart';
 import 'package:sharezone_widgets/sharezone_widgets.dart';
 
 enum _EventModelSheetAction { edit, delete, report }
@@ -152,7 +151,7 @@ class _TimetableEventDetailsPage extends StatelessWidget {
     final isAuthor = api.uID == event.authorID;
     final hasPermissionsToManageLessons = hasPermissionToManageEvents(
         api.course.getRoleFromCourseNoSync(event.groupID)!, isAuthor);
-    final isExam = event.eventType == Exam();
+    final isExam = event.eventType == EventType.exam;
     final theme = Theme.of(context);
 
     return Scaffold(
@@ -198,11 +197,6 @@ class _TimetableEventDetailsPage extends StatelessWidget {
                     ),
                   ),
                 ),
-                if (event.eventType is OtherEventType == false)
-                  ListTile(
-                    leading: const Icon(Icons.label),
-                    title: Text("Art: ${event.eventType.name}"),
-                  ),
                 ListTile(
                   leading: const Icon(Icons.place),
                   title: Text("Raum: ${event.place ?? "-"}"),

app/test/timetable/timetable_bloc_test.dart

@@ -16,7 +16,6 @@ import 'package:date/weektype.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:group_domain_models/group_domain_models.dart';
 import 'package:sharezone/calendrical_events/models/calendrical_event.dart';
-import 'package:sharezone/calendrical_events/models/calendrical_event_types.dart';
 import 'package:sharezone/timetable/src/bloc/timetable_bloc.dart';
 import 'package:sharezone/timetable/src/models/lesson.dart';
 import 'package:sharezone/timetable/timetable_page/school_class_filter/school_class_filter_view.dart';
@@ -73,7 +72,7 @@ void main() {
         date: Date.today(),
         detail: '',
         eventID: 'eventId',
-        eventType: Meeting(),
+        eventType: EventType.event,
         latestEditor: '',
         sendNotification: false,
         title: 'title',