✨ Handle for month

Author: Shubham Jitiya

lib/src/event_controller.dart

@@ -124,6 +124,47 @@ class EventController<T extends Object?> extends ChangeNotifier {
         return currentDate.isBefore(endDate);
     }
   }
+
+  bool _isMonthlyRecurrence({
+    required DateTime currentDate,
+    required DateTime startDate,
+    required RecurrenceSettings recurrenceSettings,
+  }) {
+    final recurrenceEndDate = recurrenceSettings.endDate;
+    final interval = recurrenceSettings.interval;
+
+    switch (recurrenceSettings.recurrenceEndOn) {
+      case RecurrenceEnd.never:
+        return currentDate.day == startDate.day;
+      case RecurrenceEnd.on:
+        return recurrenceEndDate != null &&
+            (currentDate.day == startDate.day) &&
+            currentDate.isBefore(recurrenceEndDate.add(
+              Duration(days: 1),
+            ));
+
+      /// Calculate the last valid occurrence based on the interval count
+      /// `interval - 1` is used here because:
+      /// - The `interval` represents the total number of occurrences, including the starting month.
+      /// - Subtracting 1 allows us to calculate the number of additional months to add
+      ///   after the start month to get to the final occurrence.
+      /// For example, if `interval = 3`, occurrences should happen in:
+      /// - Start month (1st occurrence), plus two additional months to reach the 3rd occurrence.
+      case RecurrenceEnd.after:
+        if (interval == null || interval <= 1) {
+          return false;
+        }
+        final lastOccurrenceDate = DateTime(
+          startDate.year,
+          startDate.month + (interval - 1),
+          startDate.day,
+        );
+        return (currentDate.day == startDate.day) &&
+            currentDate.isBefore(lastOccurrenceDate.add(
+              Duration(days: 1),
+            ));
+    }
+  }
   //#endregion
 
   //#region Public Methods
@@ -251,7 +292,7 @@ class EventController<T extends Object?> extends ChangeNotifier {
         case RepeatFrequency.monthly:
           final isWeeklyRecurrence = _isMonthlyRecurrence(
             currentDate: date,
-            eventEnd: event.endDate,
+            startDate: event.date,
             recurrenceSettings: recurrenceSettings,
           );
           if (isWeeklyRecurrence) {
@@ -262,7 +303,6 @@ class EventController<T extends Object?> extends ChangeNotifier {
           // TODO: Handle this case.
           break;
         case RepeatFrequency.doNotRepeat:
-          // TODO: Handle this case.
           break;
       }
     }