Calendar invitations for Mail part of the app.

Wino.Core/Requests/Calendar/UpdateCalendarEventRequest.cs

@@ -0,0 +1,53 @@
+using System.Collections.Generic;
+using CommunityToolkit.Mvvm.Messaging;
+using Wino.Core.Domain.Entities.Calendar;
+using Wino.Core.Domain.Enums;
+using Wino.Core.Domain.Models.Requests;
+using Wino.Messaging.Client.Calendar;
+
+namespace Wino.Core.Requests.Calendar;
+
+/// <summary>
+/// Request to update an existing calendar event on the server.
+/// The calendar item should be already updated in the local database before queuing this request.
+/// </summary>
+public record UpdateCalendarEventRequest(CalendarItem Item, List<CalendarEventAttendee> Attendees) : CalendarRequestBase(Item)
+{
+    /// <summary>
+    /// Original attendees before the update, used for reverting changes if the update fails.
+    /// </summary>
+    public List<CalendarEventAttendee> OriginalAttendees { get; init; }
+
+    /// <summary>
+    /// Original calendar item state before the update, used for reverting changes if the update fails.
+    /// </summary>
+    public CalendarItem OriginalItem { get; init; }
+
+    public override CalendarSynchronizerOperation Operation => CalendarSynchronizerOperation.UpdateEvent;
+
+    /// <summary>
+    /// After successful update, we need to resync to ensure changes are properly reflected.
+    /// </summary>
+    public override int ResynchronizationDelay => 2000;
+
+    public override void ApplyUIChanges()
+    {
+        // Notify UI that the event was updated locally
+        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+    }
+
+    public override void RevertUIChanges()
+    {
+        // If update fails, restore the original state
+        if (OriginalItem != null && OriginalAttendees != null)
+        {
+            // Send the original item back to restore UI state
+            WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(OriginalItem));
+        }
+        else
+        {
+            // Fallback: just notify with current item to trigger refresh
+            WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+        }
+    }
+}