Fix double init on calendar days.

Wino.Calendar.ViewModels/CalendarPageViewModel.cs

@@ -168,29 +168,28 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
 
         AccountCalendarStateService.AccountCalendarSelectionStateChanged += UpdateAccountCalendarRequested;
         AccountCalendarStateService.CollectiveAccountGroupSelectionStateChanged += AccountCalendarStateCollectivelyChanged;
+
+        // We don't register on navigation here. This page is cached.
+        RegisterRecipients();
     }
 
     protected override void RegisterRecipients()
     {
         base.RegisterRecipients();
 
-        Messenger.Register<LoadCalendarMessage>(this);
-        Messenger.Register<CalendarSettingsUpdatedMessage>(this);
-        Messenger.Register<CalendarItemTappedMessage>(this);
-        Messenger.Register<CalendarItemDoubleTappedMessage>(this);
-        Messenger.Register<CalendarItemRightTappedMessage>(this);
-        Messenger.Register<AccountRemovedMessage>(this);
-    }
-    protected override void UnregisterRecipients()
-    {
-        base.UnregisterRecipients();
-
         Messenger.Unregister<LoadCalendarMessage>(this);
         Messenger.Unregister<CalendarSettingsUpdatedMessage>(this);
         Messenger.Unregister<CalendarItemTappedMessage>(this);
         Messenger.Unregister<CalendarItemDoubleTappedMessage>(this);
         Messenger.Unregister<CalendarItemRightTappedMessage>(this);
         Messenger.Unregister<AccountRemovedMessage>(this);
+
+        Messenger.Register<LoadCalendarMessage>(this);
+        Messenger.Register<CalendarSettingsUpdatedMessage>(this);
+        Messenger.Register<CalendarItemTappedMessage>(this);
+        Messenger.Register<CalendarItemDoubleTappedMessage>(this);
+        Messenger.Register<CalendarItemRightTappedMessage>(this);
+        Messenger.Register<AccountRemovedMessage>(this);
     }
 
     private void AccountCalendarStateCollectivelyChanged(object sender, GroupedAccountCalendarViewModel e)
@@ -234,19 +233,10 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
 
     public override void OnNavigatedTo(NavigationMode mode, object parameters)
     {
-        base.OnNavigatedTo(mode, parameters);
-
-        if (mode == NavigationMode.Back)
-        {
-            // We unregister recipients on navigate-away, so mutations that happened while this page
-            // was not active (e.g. CalendarItemDeleted from details page) can be missed.
-            // Rehydrate currently visible ranges to guarantee UI and DB are consistent on return.
-            _ = RefreshVisibleRangesAsync();
-            return;
-        }
-
         RefreshSettings();
 
+        if (mode == NavigationMode.Back) return;
+
         // Automatically select the first primary calendar for quick event dialog.
         SelectedQuickEventAccountCalendar = AccountCalendarStateService.ActiveCalendars.FirstOrDefault(a => a.IsPrimary);
     }

Wino.Mail.WinUI/Services/NavigationService.cs

@@ -6,6 +6,7 @@ using Microsoft.UI.Xaml.Controls;
 using Wino.Calendar.Views;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Calendar;
 using Wino.Core.Domain.Models.Navigation;
 using Wino.Helpers;
 using Wino.Mail.ViewModels.Data;
@@ -15,6 +16,7 @@ using Wino.Mail.WinUI.Interfaces;
 using Wino.Mail.WinUI.Services;
 using Wino.Mail.WinUI.Views.Calendar;
 using Wino.Messaging.Client.Mails;
+using Wino.Messaging.Client.Calendar;
 using Wino.Messaging.Client.Navigation;
 using Wino.Views;
 using Wino.Views.Account;
@@ -136,6 +138,7 @@ public class NavigationService : NavigationServiceBase, INavigationService
                          NavigationTransitionType transition = NavigationTransitionType.None)
     {
         var pageType = GetPageType(page);
+        if (pageType == null) return false;
 
         var currentApplicationMode = GetCoreFrame(NavigationReferenceFrame.ShellFrame)?.Content?.GetType() == typeof(MailAppShell)
             ? WinoApplicationMode.Mail
@@ -151,6 +154,30 @@ public class NavigationService : NavigationServiceBase, INavigationService
             // Calendar navigations.
             if (currentApplicationMode == WinoApplicationMode.Calendar)
             {
+                var currentFrameType = GetCurrentFrameType(ref innerShellFrame);
+
+                if (page == WinoPage.CalendarPage &&
+                    parameter is CalendarPageNavigationArgs calendarNavigationArgs)
+                {
+                    var loadCalendarMessage = CreateLoadCalendarMessage(calendarNavigationArgs);
+
+                    // Date changes while CalendarPage is already active should not re-navigate the frame.
+                    if (currentFrameType == pageType)
+                    {
+                        WeakReferenceMessenger.Default.Send(loadCalendarMessage);
+                        return true;
+                    }
+
+                    // If CalendarPage is the previous page, reuse it instead of creating a second instance.
+                    var lastBackStackEntry = innerShellFrame.BackStack.Count > 0 ? innerShellFrame.BackStack[^1] : null;
+                    if (innerShellFrame.CanGoBack && lastBackStackEntry?.SourcePageType == pageType)
+                    {
+                        innerShellFrame.GoBack();
+                        WeakReferenceMessenger.Default.Send(loadCalendarMessage);
+                        return true;
+                    }
+                }
+
                 return innerShellFrame.Navigate(pageType, parameter);
             }
             else
@@ -221,6 +248,19 @@ public class NavigationService : NavigationServiceBase, INavigationService
         return false;
     }
 
+    private static LoadCalendarMessage CreateLoadCalendarMessage(CalendarPageNavigationArgs args)
+    {
+        var targetDate = args.RequestDefaultNavigation
+            ? DateTime.Now.Date
+            : args.NavigationDate;
+
+        var initiative = args.RequestDefaultNavigation
+            ? CalendarInitInitiative.App
+            : CalendarInitInitiative.User;
+
+        return new LoadCalendarMessage(targetDate, initiative);
+    }
+
     public void GoBack(Core.Domain.Enums.NavigationTransitionEffect slideEffect = Core.Domain.Enums.NavigationTransitionEffect.FromRight)
     {
         // Check if we're navigating within ManageAccountsPage (applies to both modes)