From b0a4068224386258cf3019dae462530037d21f25 Mon Sep 17 00:00:00 2001
From: Jaap Aarts <JAicewizard@users.noreply.github.com>
Date: Sat, 2 Sep 2023 15:21:46 +0200
Subject: [PATCH] Fix calendar not adding a day for today if there are no later
 events (#453)

---
 lib/ui/screens/calendar_screen.dart |  2 +-
 lib/ui/widgets/events.dart          | 49 ++++++++++++++++++++++-------
 test/unit/calendar_test.dart        | 22 ++++++++++++-
 3 files changed, 60 insertions(+), 13 deletions(-)

diff --git a/lib/ui/screens/calendar_screen.dart b/lib/ui/screens/calendar_screen.dart
index 09b1e2be7..e81bdc492 100644
--- a/lib/ui/screens/calendar_screen.dart
+++ b/lib/ui/screens/calendar_screen.dart
@@ -253,7 +253,7 @@ class CalendarScrollView extends StatelessWidget {
             calendarState.resultsDown.isNotEmpty,
         _monthGroupedEventsDown = calendarState.resultsDown.isEmpty
             ? List.empty()
-            : ensureContainsToday(
+            : ensureMonthsContainsToday(
                 groupByMonth(calendarState.resultsDown)
                     .sortedBy((element) => element.month),
                 now),
diff --git a/lib/ui/widgets/events.dart b/lib/ui/widgets/events.dart
index 2d3bca3c0..738131333 100644
--- a/lib/ui/widgets/events.dart
+++ b/lib/ui/widgets/events.dart
@@ -17,7 +17,7 @@ class CalendarViewDay {
       : events = events.sortedBy((element) => element.start);
 }
 
-List<CalendarViewMonth> ensureContainsToday(
+List<CalendarViewMonth> ensureMonthsContainsToday(
     List<CalendarViewMonth> events, DateTime now) {
   DateTime today = DateTime(
     now.year,
@@ -28,30 +28,57 @@ List<CalendarViewMonth> ensureContainsToday(
     now.year,
     now.month,
   );
+  CalendarViewDay emptyDay = CalendarViewDay(day: today, events: []);
   for (var i = 0; i < events.length; i++) {
     if (events[i].month.isAfter(thisMonth)) {
+      // The current month does not exist yet
+      // Make a new month with only today
       events.insert(i, CalendarViewMonth(month: thisMonth, events: []));
-      events[i].days.add(CalendarViewDay(day: today, events: []));
-
+      events[i].days.add(emptyDay);
       return events;
     }
     if (events[i].month == thisMonth) {
-      for (var j = 0; j < events[i].days.length; j++) {
-        if (events[i].days[j].day == today) return events;
-        if (events[i].days[j].day.isAfter(today)) {
-          events[i].days.insert(j, CalendarViewDay(day: today, events: []));
-          return events;
-        }
-      }
+      events[i] = ensureMonthContainsDay(events[i], now.day);
       return events;
     }
   }
+  // We did not find the current month, and there was no month after the current month
+  // Add a new month to the end
   events.add(CalendarViewMonth(month: thisMonth, events: []));
-  events.last.days.add(CalendarViewDay(day: today, events: []));
+  events.last.days.add(emptyDay);
 
   return events;
 }
 
+CalendarViewMonth ensureMonthContainsDay(CalendarViewMonth month, int day) {
+  DateTime thisMonth = month.month;
+  DateTime today = DateTime(
+    thisMonth.year,
+    thisMonth.month,
+    day,
+  );
+
+  CalendarViewDay emptyDay = CalendarViewDay(day: today, events: []);
+  // Try to find the right day, or a day after
+  for (var j = 0; j < month.days.length; j++) {
+    if (month.days[j].day == today) {
+      // There already exists a day for today in the calendar
+      // Nothing to be done
+      return month;
+    }
+    if (month.days[j].day.isAfter(today)) {
+      // We did not find today, but there was is a day after today
+      // Insert a new day
+      month.days.insert(j, emptyDay);
+      return month;
+    }
+  }
+  // We did not find today, and there was no day after today
+  // Add a new to to the end
+  month.days.add(emptyDay);
+  return month;
+}
+
 List<CalendarViewMonth> groupByMonth(
   List<CalendarEvent> eventList,
 ) =>
diff --git a/test/unit/calendar_test.dart b/test/unit/calendar_test.dart
index a10c18c75..1c5832045 100644
--- a/test/unit/calendar_test.dart
+++ b/test/unit/calendar_test.dart
@@ -120,7 +120,27 @@ void main() {
       );
 
       final calendarEvents = CalendarEvent.splitEventIntoCalendarEvents(event);
-      final monthGroupedEventsDown = ensureContainsToday(
+      final monthGroupedEventsDown = ensureMonthsContainsToday(
+          groupByMonth(calendarEvents).sortedBy((element) => element.month),
+          now);
+
+      expect(monthGroupedEventsDown.length, 2);
+      expect(monthGroupedEventsDown[1].days.length, 1);
+      expect(monthGroupedEventsDown[1].days[0].events.length, 0);
+    });
+    test('AddToEnd', () {
+      final now = DateTime.parse('2022-04-05 13:37');
+      final event = FakeEvent(
+        pk: 1,
+        title: 'Lorem',
+        description: 'Ipsum',
+        start: DateTime.parse('2022-03-04 13:37'),
+        end: DateTime.parse('2022-03-04 14:37'),
+        location: 'Dolor',
+      );
+
+      final calendarEvents = CalendarEvent.splitEventIntoCalendarEvents(event);
+      final monthGroupedEventsDown = ensureMonthsContainsToday(
           groupByMonth(calendarEvents).sortedBy((element) => element.month),
           now);