Event details page improvements, calendar item update source.

Wino.Calendar.ViewModels/CalendarAccountSettingsPageViewModel.cs

@@ -60,29 +60,30 @@ public partial class CalendarAccountSettingsPageViewModel : CalendarBaseViewMode
     {
         base.OnNavigatedTo(mode, parameters);
 
-        if (parameters is not Guid accountId)
+        if (parameters is AccountCalendar selectedCalendar)
+        {
+            Account = await _accountService.GetAccountAsync(selectedCalendar.AccountId);
+            AccountCalendar = await _calendarService.GetAccountCalendarAsync(selectedCalendar.Id) ?? selectedCalendar;
+        }
+        else if (parameters is Guid accountId)
+        {
+            Account = await _accountService.GetAccountAsync(accountId);
+            var calendars = await _calendarService.GetAccountCalendarsAsync(accountId);
+            AccountCalendar = calendars.FirstOrDefault(c => c.IsPrimary) ?? calendars.FirstOrDefault();
+        }
+        else
+        {
             return;
+        }
 
-        // Load account
+        if (Account == null || AccountCalendar == null)
-        Account = await _accountService.GetAccountAsync(accountId);
-        
-        if (Account == null)
-            return;
-
-        // Load first primary calendar for this account
-        var calendars = await _calendarService.GetAccountCalendarsAsync(accountId);
-        AccountCalendar = calendars.FirstOrDefault(c => c.IsPrimary) ?? calendars.FirstOrDefault();
-
-        if (AccountCalendar == null)
             return;
 
         // Initialize properties from AccountCalendar
         AccountColorHex = AccountCalendar.BackgroundColorHex ?? "#0078D4";
-        IsSyncEnabled = AccountCalendar.IsExtended;
+        IsSyncEnabled = AccountCalendar.IsSynchronizationEnabled;
         IsPrimaryCalendar = AccountCalendar.IsPrimary;
-
+        SelectedDefaultShowAsOption = ShowAsOptions.FirstOrDefault(o => o.ShowAs == AccountCalendar.DefaultShowAs) ?? ShowAsOptions[2];
-        // TODO: Default ShowAs is not stored in AccountCalendar yet, defaulting to Busy
-        SelectedDefaultShowAsOption = ShowAsOptions[2]; // Busy
     }
 
     partial void OnAccountColorHexChanged(string value)
@@ -98,7 +99,7 @@ public partial class CalendarAccountSettingsPageViewModel : CalendarBaseViewMode
     {
         if (AccountCalendar != null)
         {
-            AccountCalendar.IsExtended = value;
+            AccountCalendar.IsSynchronizationEnabled = value;
             SaveChangesAsync();
         }
     }
@@ -114,11 +115,10 @@ public partial class CalendarAccountSettingsPageViewModel : CalendarBaseViewMode
 
     partial void OnSelectedDefaultShowAsOptionChanged(ShowAsOption value)
     {
-        // TODO: Default ShowAs should be stored in AccountCalendar or account preferences
+        if (AccountCalendar != null && value != null)
-        // For now, this is just a placeholder as the property doesn't exist yet
-        if (value != null)
         {
-            // Future: Store value.ShowAs somewhere
+            AccountCalendar.DefaultShowAs = value.ShowAs;
+            SaveChangesAsync();
         }
     }
 

Wino.Calendar.ViewModels/CalendarPageViewModel.cs

@@ -286,6 +286,7 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
                 Description = string.Empty,
                 Location = Location ?? string.Empty,
                 Title = EventName,
+                ShowAs = SelectedQuickEventAccountCalendar.DefaultShowAs,
                 IsHidden = false,
                 AssignedCalendar = SelectedQuickEventAccountCalendar
             };
@@ -907,9 +908,9 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
         });
     }
 
-    protected override async void OnCalendarItemUpdated(CalendarItem calendarItem)
+    protected override async void OnCalendarItemUpdated(CalendarItem calendarItem, CalendarItemUpdateSource source)
     {
-        base.OnCalendarItemUpdated(calendarItem);
+        base.OnCalendarItemUpdated(calendarItem, source);
         Debug.WriteLine($"Calendar item updated: {calendarItem.Id}");
 
         // Series master events should not be visible on the UI.

Wino.Calendar.ViewModels/Data/AccountCalendarViewModel.cs

@@ -2,6 +2,7 @@
 using CommunityToolkit.Mvvm.ComponentModel;
 using Wino.Core.Domain.Entities.Calendar;
 using Wino.Core.Domain.Entities.Shared;
+using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 
 namespace Wino.Calendar.ViewModels.Data;
@@ -54,6 +55,12 @@ public partial class AccountCalendarViewModel : ObservableObject, IAccountCalend
         set => SetProperty(AccountCalendar.IsPrimary, value, AccountCalendar, (u, i) => u.IsPrimary = i);
     }
 
+    public bool IsSynchronizationEnabled
+    {
+        get => AccountCalendar.IsSynchronizationEnabled;
+        set => SetProperty(AccountCalendar.IsSynchronizationEnabled, value, AccountCalendar, (u, i) => u.IsSynchronizationEnabled = i);
+    }
+
     public Guid AccountId
     {
         get => AccountCalendar.AccountId;
@@ -65,6 +72,12 @@ public partial class AccountCalendarViewModel : ObservableObject, IAccountCalend
         get => AccountCalendar.RemoteCalendarId;
         set => SetProperty(AccountCalendar.RemoteCalendarId, value, AccountCalendar, (u, r) => u.RemoteCalendarId = r);
     }
+
+    public CalendarItemShowAs DefaultShowAs
+    {
+        get => AccountCalendar.DefaultShowAs;
+        set => SetProperty(AccountCalendar.DefaultShowAs, value, AccountCalendar, (u, s) => u.DefaultShowAs = s);
+    }
     public Guid Id { get => ((IAccountCalendar)AccountCalendar).Id; set => ((IAccountCalendar)AccountCalendar).Id = value; }
     public MailAccount MailAccount { get => MailAccount; set => MailAccount = value; }
 }

Wino.Calendar.ViewModels/EventDetailsPageViewModel.cs

@@ -105,6 +105,7 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
     public bool IncludeRsvpMessage => !string.IsNullOrEmpty(RsvpMessage);
 
     [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(IncludeRsvpMessage))]
     public partial string RsvpMessage { get; set; } = string.Empty;
 
     public ObservableCollection<RsvpStatusOption> RsvpStatusOptions { get; } = new ObservableCollection<RsvpStatusOption>();
@@ -129,7 +130,7 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
                 CalendarItemStatus.Tentative => Translator.CalendarEventResponse_TentativeResponse,
                 CalendarItemStatus.Cancelled => Translator.CalendarEventResponse_DeclinedResponse,
                 CalendarItemStatus.NotResponded => Translator.CalendarEventResponse_NotResponded,
-                _ => throw new NotImplementedException()
+                _ => Translator.CalendarEventResponse_NotResponded
             };
         }
     }
@@ -179,19 +180,33 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
         await LoadCalendarItemTargetAsync(args);
     }
 
-    protected override async void OnCalendarItemUpdated(CalendarItem calendarItem)
+    protected override async void OnCalendarItemUpdated(CalendarItem calendarItem, CalendarItemUpdateSource source)
     {
-        base.OnCalendarItemUpdated(calendarItem);
+        base.OnCalendarItemUpdated(calendarItem, source);
 
         // If the current event was updated, reload it
         if (CurrentEvent?.CalendarItem?.Id == calendarItem.Id || CurrentEvent?.CalendarItem.RecurringCalendarItemId == calendarItem.Id)
         {
-            // Refresh the current event data by reloading from service
+            // Reflect client-side optimistic changes immediately; fallback to DB for server updates.
+            if (source == CalendarItemUpdateSource.ClientUpdated || source == CalendarItemUpdateSource.ClientReverted)
+            {
+                var previousAttendees = CurrentEvent?.Attendees?.ToList() ?? [];
+                CurrentEvent = new CalendarItemViewModel(calendarItem);
+
+                foreach (var attendee in previousAttendees)
+                {
+                    CurrentEvent.Attendees.Add(attendee);
+                }
+
+                return;
+            }
+
+            // Refresh from DB when update comes from server sync.
             var refreshedEvent = await _calendarService.GetCalendarItemAsync(calendarItem.Id);
             if (refreshedEvent != null)
             {
                 CurrentEvent = new CalendarItemViewModel(refreshedEvent);
-                await LoadAttendeesAsync(refreshedEvent.EventTrackingId, refreshedEvent);
+                await LoadAttendeesAsync(refreshedEvent.Id, refreshedEvent);
             }
         }
     }
@@ -218,17 +233,17 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
 
             CurrentEvent = new CalendarItemViewModel(currentEventItem);
 
-            await LoadAttendeesAsync(currentEventItem.EventTrackingId, currentEventItem);
+            await LoadAttendeesAsync(currentEventItem.Id, currentEventItem);
 
             // Initialize SelectedShowAsOption based on current event's ShowAs
             SelectedShowAsOption = ShowAsOptions.FirstOrDefault(o => o.ShowAs == currentEventItem.ShowAs) ?? ShowAsOptions[2];
 
             // Load reminders for this calendar item
-            Reminders = await _calendarService.GetRemindersAsync(currentEventItem.EventTrackingId);
+            Reminders = await _calendarService.GetRemindersAsync(currentEventItem.Id);
             InitializeReminderOptions();
 
             // Load attachments
-            await LoadAttachmentsAsync(currentEventItem.EventTrackingId);
+            await LoadAttachmentsAsync(currentEventItem.Id);
         }
         catch (Exception ex)
         {
@@ -236,11 +251,11 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
         }
     }
 
-    private async Task LoadAttendeesAsync(Guid eventTrackingId, CalendarItem calendarItem)
+    private async Task LoadAttendeesAsync(Guid calendarItemId, CalendarItem calendarItem)
     {
         CurrentEvent.Attendees.Clear();
 
-        var attendees = await _calendarService.GetAttendeesAsync(eventTrackingId);
+        var attendees = await _calendarService.GetAttendeesAsync(calendarItemId);
 
         // Separate organizer from other attendees to ensure organizer is always first
         var organizer = attendees.FirstOrDefault(a => a.IsOrganizer);
@@ -348,7 +363,7 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
         {
             // Capture original state BEFORE making any changes for potential revert
             var originalItem = await _calendarService.GetCalendarItemAsync(CurrentEvent.CalendarItem.Id);
-            var originalAttendees = await _calendarService.GetAttendeesAsync(CurrentEvent.CalendarItem.EventTrackingId);
+            var originalAttendees = await _calendarService.GetAttendeesAsync(CurrentEvent.CalendarItem.Id);
 
             // Get selected reminder options
             var selectedOptions = ReminderOptions.Where(o => o.IsSelected).ToList();
@@ -370,7 +385,7 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
             }
 
             // Save reminders to database
-            await _calendarService.SaveRemindersAsync(CurrentEvent.CalendarItem.EventTrackingId, newReminders);
+            await _calendarService.SaveRemindersAsync(CurrentEvent.CalendarItem.Id, newReminders);
             Reminders = newReminders;
 
             // Update ShowAs if changed
@@ -499,7 +514,7 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
             await _winoRequestDelegator.ExecuteAsync(preparationRequest);
 
             // Reload attendees to get the updated status from the server
-            await LoadAttendeesAsync(CurrentEvent.CalendarItem.EventTrackingId, CurrentEvent.CalendarItem);
+            await LoadAttendeesAsync(CurrentEvent.CalendarItem.Id, CurrentEvent.CalendarItem);
 
             OnPropertyChanged(nameof(CurrentRsvpText));
             OnPropertyChanged(nameof(CurrentRsvpStatus));

Wino.Calendar/Views/EventDetailsPage.xaml

@@ -6,9 +6,12 @@
     xmlns:abstract="using:Wino.Calendar.Views.Abstract"
     xmlns:calendar="using:Wino.Core.Domain.Entities.Calendar"
     xmlns:calendarHelpers="using:Wino.Calendar.Helpers"
+    xmlns:calendarViewModels="using:Wino.Calendar.ViewModels"
     xmlns:coreControls="using:Wino.Core.UWP.Controls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:data="using:Wino.Calendar.ViewModels.Data"
     xmlns:domain="using:Wino.Core.Domain"
+    xmlns:enums="using:Wino.Core.Domain.Enums"
     xmlns:helpers="using:Wino.Helpers"
     xmlns:local="using:Wino.Calendar.Views"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
@@ -43,6 +46,7 @@
     </Page.Resources>
     <Grid Padding="20">
         <Grid.RowDefinitions>
+            <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
             <RowDefinition Height="*" />
         </Grid.RowDefinitions>
@@ -60,16 +64,16 @@
                 DefaultLabelPosition="Right"
                 IsSticky="True"
                 OverflowButtonVisibility="Auto">
-                <AppBarToggleButton
+                <AppBarButton
-                    x:Name="ReadOnlyToggle"
+                    Command="{x:Bind ViewModel.SaveCommand}"
-                    Content="Read-only event"
+                    Label="{x:Bind domain:Translator.Buttons_Save}">
-                    IsChecked="True" />
-                <AppBarButton Label="{x:Bind domain:Translator.Buttons_Save}">
                     <AppBarButton.Icon>
                         <coreControls:WinoFontIcon Icon="Save" />
                     </AppBarButton.Icon>
                 </AppBarButton>
-                <AppBarButton Label="{x:Bind domain:Translator.Buttons_Delete}">
+                <AppBarButton
+                    Command="{x:Bind ViewModel.DeleteCommand}"
+                    Label="{x:Bind domain:Translator.Buttons_Delete}">
                     <AppBarButton.Icon>
                         <coreControls:WinoFontIcon Icon="Delete" />
                     </AppBarButton.Icon>
@@ -78,7 +82,9 @@
                 <AppBarSeparator />
 
                 <!--  Join Online  -->
-                <AppBarButton Label="Join Online">
+                <AppBarButton
+                    Command="{x:Bind ViewModel.JoinOnlineCommand}"
+                    Label="Join Online">
                     <AppBarButton.Icon>
                         <coreControls:WinoFontIcon Icon="EventJoinOnline" />
                     </AppBarButton.Icon>
@@ -86,27 +92,37 @@
 
                 <AppBarSeparator />
 
-                <!--  Join Options  -->
+                <!--  RSVP Actions  -->
-                <AppBarButton Label="Accept">
+                <AppBarButton
+                    Command="{x:Bind ViewModel.SendRsvpResponseCommand}"
+                    CommandParameter="{x:Bind enums:AttendeeStatus.Accepted}"
+                    Label="Accept">
                     <AppBarButton.Icon>
                         <coreControls:WinoFontIcon Foreground="#527257" Icon="EventAccept" />
                     </AppBarButton.Icon>
                 </AppBarButton>
 
-                <AppBarButton Label="Tentative">
+                <AppBarButton
+                    Command="{x:Bind ViewModel.SendRsvpResponseCommand}"
+                    CommandParameter="{x:Bind enums:AttendeeStatus.Tentative}"
+                    Label="Tentative">
                     <AppBarButton.Icon>
                         <coreControls:WinoFontIcon Foreground="#805682" Icon="EventTentative" />
                     </AppBarButton.Icon>
                 </AppBarButton>
 
-                <AppBarButton Label="Decline">
+                <AppBarButton
+                    Command="{x:Bind ViewModel.SendRsvpResponseCommand}"
+                    CommandParameter="{x:Bind enums:AttendeeStatus.Declined}"
+                    Label="Decline">
                     <AppBarButton.Icon>
                         <PathIcon Data="F1 M 10.253906 9.375 L 16.064453 15.185547 C 16.18815 15.309245 16.25 15.455729 16.25 15.625 C 16.25 15.794271 16.18815 15.940756 16.064453 16.064453 C 15.940754 16.188152 15.79427 16.25 15.625 16.25 C 15.455729 16.25 15.309244 16.188152 15.185547 16.064453 L 9.375 10.253906 L 3.564453 16.064453 C 3.440755 16.188152 3.294271 16.25 3.125 16.25 C 2.955729 16.25 2.809245 16.188152 2.685547 16.064453 C 2.561849 15.940756 2.5 15.794271 2.5 15.625 C 2.5 15.455729 2.561849 15.309245 2.685547 15.185547 L 8.496094 9.375 L 2.685547 3.564453 C 2.561849 3.440756 2.5 3.294271 2.5 3.125 C 2.5 2.95573 2.561849 2.809246 2.685547 2.685547 C 2.809245 2.56185 2.955729 2.5 3.125 2.5 C 3.294271 2.5 3.440755 2.56185 3.564453 2.685547 L 9.375 8.496094 L 15.185547 2.685547 C 15.309244 2.56185 15.455729 2.5 15.625 2.5 C 15.79427 2.5 15.940754 2.56185 16.064453 2.685547 C 16.18815 2.809246 16.25 2.95573 16.25 3.125 C 16.25 3.294271 16.18815 3.440756 16.064453 3.564453 Z " Foreground="#d94b4e" />
-
                     </AppBarButton.Icon>
                 </AppBarButton>
 
-                <AppBarButton Label="Respond">
+                <AppBarButton
+                    Command="{x:Bind ViewModel.ToggleRsvpPanelCommand}"
+                    Label="{x:Bind ViewModel.CurrentRsvpText, Mode=OneWay}">
                     <AppBarButton.Icon>
                         <coreControls:WinoFontIcon Foreground="#805682" Icon="EventRespond" />
                     </AppBarButton.Icon>
@@ -118,7 +134,11 @@
                 <AppBarElementContainer>
                     <StackPanel Style="{StaticResource ActionBarElementContainerStackStyle}">
                         <TextBlock VerticalAlignment="Center" Text="Show as" />
-                        <ComboBox Width="150" />
+                        <ComboBox
+                            Width="150"
+                            DisplayMemberPath="DisplayText"
+                            ItemsSource="{x:Bind ViewModel.ShowAsOptions}"
+                            SelectedItem="{x:Bind ViewModel.SelectedShowAsOption, Mode=TwoWay}" />
                     </StackPanel>
                 </AppBarElementContainer>
 
@@ -127,14 +147,33 @@
                     <StackPanel Style="{StaticResource ActionBarElementContainerStackStyle}">
                         <coreControls:WinoFontIcon FontSize="16" Icon="Reminder" />
                         <TextBlock VerticalAlignment="Center" Text="Reminder" />
-                        <ComboBox Width="150" />
+                        <Button Content="Set">
+                            <Button.Flyout>
+                                <Flyout>
+                                    <ListView
+                                        Width="200"
+                                        MaxHeight="300"
+                                        ItemsSource="{x:Bind ViewModel.ReminderOptions}"
+                                        SelectionMode="None">
+                                        <ListView.ItemTemplate>
+                                            <DataTemplate x:DataType="calendarViewModels:ReminderOption">
+                                                <CheckBox Content="{x:Bind DisplayText}" IsChecked="{x:Bind IsSelected, Mode=TwoWay}" />
+                                            </DataTemplate>
+                                        </ListView.ItemTemplate>
+                                    </ListView>
+                                </Flyout>
+                            </Button.Flyout>
+                        </Button>
                     </StackPanel>
                 </AppBarElementContainer>
 
                 <AppBarSeparator />
 
                 <!--  Edit Series  -->
-                <AppBarButton Label="Edit Series">
+                <AppBarButton
+                    Command="{x:Bind ViewModel.ViewSeriesCommand}"
+                    Label="Edit Series"
+                    Visibility="{x:Bind ViewModel.CanEditSeries, Mode=OneWay}">
                     <AppBarButton.Icon>
                         <coreControls:WinoFontIcon Icon="EventEditSeries" />
                     </AppBarButton.Icon>
@@ -142,8 +181,51 @@
             </CommandBar>
         </Border>
 
+        <!-- RSVP Panel -->
+        <Border
+            Grid.Row="1"
+            Margin="0,8,0,0"
+            Padding="12"
+            Background="{ThemeResource WinoContentZoneBackgroud}"
+            BorderBrush="{StaticResource CardStrokeColorDefaultBrush}"
+            BorderThickness="1"
+            CornerRadius="7"
+            Visibility="{x:Bind ViewModel.IsRsvpPanelVisible, Mode=OneWay}">
+            <Grid RowSpacing="8">
+                <Grid.RowDefinitions>
+                    <RowDefinition Height="Auto" />
+                    <RowDefinition Height="Auto" />
+                </Grid.RowDefinitions>
+
+                <StackPanel Orientation="Horizontal" Spacing="8">
+                    <Button
+                        Command="{x:Bind ViewModel.SendRsvpResponseCommand}"
+                        CommandParameter="{x:Bind enums:AttendeeStatus.Accepted}"
+                        Content="Accept" />
+                    <Button
+                        Command="{x:Bind ViewModel.SendRsvpResponseCommand}"
+                        CommandParameter="{x:Bind enums:AttendeeStatus.Tentative}"
+                        Content="Tentative" />
+                    <Button
+                        Command="{x:Bind ViewModel.SendRsvpResponseCommand}"
+                        CommandParameter="{x:Bind enums:AttendeeStatus.Declined}"
+                        Content="Decline" />
+                    <Button
+                        Command="{x:Bind ViewModel.CloseRsvpPanelCommand}"
+                        Content="Close" />
+                </StackPanel>
+
+                <TextBox
+                    Grid.Row="1"
+                    AcceptsReturn="True"
+                    PlaceholderText="Add a message (optional)"
+                    Text="{x:Bind ViewModel.RsvpMessage, Mode=TwoWay}"
+                    TextWrapping="Wrap" />
+            </Grid>
+        </Border>
+
         <!--  Event details  -->
-        <ScrollViewer Grid.Row="1">
+        <ScrollViewer Grid.Row="2">
             <Grid>
                 <Grid.ColumnDefinitions>
                     <ColumnDefinition Width="2*" />
@@ -170,8 +252,7 @@
                         <!--  Read-Only Event  -->
                         <Grid
                             x:Name="ReadOnlyDetailsGrid"
-                            RowSpacing="6"
+                            RowSpacing="6">
-                            Visibility="{x:Bind ReadOnlyToggle.IsChecked, Mode=OneWay}">
                             <Grid.RowDefinitions>
                                 <RowDefinition Height="Auto" />
                                 <RowDefinition Height="16" />
@@ -195,7 +276,7 @@
                             <Grid
                                 Grid.Row="3"
                                 ColumnSpacing="6"
-                                Visibility="{x:Bind ViewModel.CurrentEvent.IsRecurringEvent}">
+                                Visibility="{x:Bind ViewModel.CurrentEvent.IsRecurringEvent, Mode=OneWay}">
                                 <Grid.ColumnDefinitions>
                                     <ColumnDefinition Width="Auto" />
                                     <ColumnDefinition Width="*" />
@@ -208,12 +289,6 @@
                                     Text="{x:Bind calendarHelpers:CalendarXamlHelpers.GetRecurrenceString(ViewModel.CurrentEvent), Mode=OneWay}"
                                     TextWrapping="Wrap" />
                             </Grid>
-
-                        </Grid>
-
-                        <!--  Editable Event  -->
-                        <Grid Visibility="{x:Bind helpers:XamlHelpers.ReverseVisibilityConverter(ReadOnlyDetailsGrid.Visibility), Mode=OneWay}">
-                            <TextBlock Text="editing" />
                         </Grid>
                     </Grid>
                 </Grid>
@@ -238,7 +313,8 @@
                         <AutoSuggestBox
                             Margin="6,0"
                             BorderThickness="0"
-                            PlaceholderText="Invite someone" />
+                            PlaceholderText="Invite someone"
+                            Visibility="{x:Bind ViewModel.IsCurrentUserOrganizer, Mode=OneWay}" />
 
                         <ListView
                             Grid.Row="1"
@@ -251,6 +327,7 @@
                                         <Grid.ColumnDefinitions>
                                             <ColumnDefinition Width="Auto" />
                                             <ColumnDefinition Width="*" />
+                                            <ColumnDefinition Width="Auto" />
                                         </Grid.ColumnDefinitions>
 
                                         <PersonPicture
@@ -285,6 +362,19 @@
                                                     Text="{x:Bind domain:Translator.CalendarEventDetails_Organizer}" />
                                             </Border>
                                         </Grid>
+
+                                        <Border
+                                            Grid.Column="2"
+                                            Padding="6,2"
+                                            HorizontalAlignment="Right"
+                                            VerticalAlignment="Center"
+                                            Background="{ThemeResource CardStrokeColorDefaultBrush}"
+                                            CornerRadius="4">
+                                            <TextBlock
+                                                FontSize="11"
+                                                Foreground="{ThemeResource TextFillColorSecondaryBrush}"
+                                                Text="{x:Bind AttendenceStatus}" />
+                                        </Border>
                                     </Grid>
                                 </DataTemplate>
                             </ListView.ItemTemplate>
@@ -296,7 +386,8 @@
                 <Grid
                     x:Name="AttachmentsGrid"
                     Grid.Column="2"
-                    Style="{StaticResource EventDetailsPanelGridStyle}">
+                    Style="{StaticResource EventDetailsPanelGridStyle}"
+                    Visibility="{x:Bind ViewModel.HasAttachments, Mode=OneWay}">
                     <Grid.RowDefinitions>
                         <RowDefinition Height="Auto" />
                         <RowDefinition Height="*" />
@@ -304,6 +395,82 @@
 
                     <TextBlock Style="{StaticResource EventDetailsPanelTitleStyle}" Text="Attachments" />
 
+                    <ListView
+                        Grid.Row="1"
+                        IsItemClickEnabled="True"
+                        ItemClick="AttachmentClicked"
+                        ItemsSource="{x:Bind ViewModel.Attachments, Mode=OneWay}"
+                        SelectionMode="None">
+                        <ListView.ItemTemplate>
+                            <DataTemplate x:DataType="data:CalendarAttachmentViewModel">
+                                <Grid Height="51">
+                                    <Grid.RowDefinitions>
+                                        <RowDefinition Height="50" />
+                                        <RowDefinition Height="*" />
+                                    </Grid.RowDefinitions>
+                                    <Grid
+                                        Grid.Row="0"
+                                        Height="50"
+                                        Background="Transparent"
+                                        ColumnSpacing="6">
+                                        <Grid.ContextFlyout>
+                                            <MenuFlyout Placement="Right">
+                                                <MenuFlyoutItem
+                                                    Click="OpenCalendarAttachment_Click"
+                                                    CommandParameter="{x:Bind}"
+                                                    Text="{x:Bind domain:Translator.Buttons_Open}" />
+                                                <MenuFlyoutItem
+                                                    Click="SaveCalendarAttachment_Click"
+                                                    CommandParameter="{x:Bind}"
+                                                    Text="{x:Bind domain:Translator.Buttons_Save}" />
+                                            </MenuFlyout>
+                                        </Grid.ContextFlyout>
+                                        <Grid.ColumnDefinitions>
+                                            <ColumnDefinition Width="24" />
+                                            <ColumnDefinition Width="*" />
+                                        </Grid.ColumnDefinitions>
+
+                                        <SymbolIcon Symbol="Attach" />
+
+                                        <Grid
+                                            Grid.Column="1"
+                                            MaxWidth="200"
+                                            HorizontalAlignment="Left"
+                                            VerticalAlignment="Center">
+                                            <Grid.RowDefinitions>
+                                                <RowDefinition Height="Auto" />
+                                                <RowDefinition Height="*" />
+                                            </Grid.RowDefinitions>
+
+                                            <TextBlock
+                                                FontSize="13"
+                                                MaxLines="1"
+                                                Text="{x:Bind FileName}"
+                                                TextTrimming="CharacterEllipsis"
+                                                TextWrapping="Wrap" />
+
+                                            <TextBlock
+                                                Grid.Row="1"
+                                                HorizontalAlignment="Right"
+                                                VerticalAlignment="Bottom"
+                                                FontSize="11"
+                                                Foreground="Gray"
+                                                Text="{x:Bind ReadableSize}" />
+                                        </Grid>
+                                    </Grid>
+                                    <ProgressBar
+                                        Grid.Row="1"
+                                        Margin="0,-5,0,0"
+                                        HorizontalAlignment="Stretch"
+                                        VerticalAlignment="Top"
+                                        IsIndeterminate="{x:Bind IsBusy, Mode=OneWay}"
+                                        ShowError="False"
+                                        ShowPaused="False"
+                                        Visibility="{x:Bind IsBusy, Mode=OneWay}" />
+                                </Grid>
+                            </DataTemplate>
+                        </ListView.ItemTemplate>
+                    </ListView>
                 </Grid>
             </Grid>
         </ScrollViewer>

Wino.Calendar/Views/EventDetailsPage.xaml.cs

@@ -1,4 +1,5 @@
-
+using Windows.UI.Xaml.Controls;
+using Wino.Calendar.ViewModels.Data;
 using Wino.Calendar.Views.Abstract;
 
 namespace Wino.Calendar.Views;
@@ -9,4 +10,28 @@ public sealed partial class EventDetailsPage : EventDetailsPageAbstract
     {
         this.InitializeComponent();
     }
+
+    private void AttachmentClicked(object sender, ItemClickEventArgs e)
+    {
+        if (e.ClickedItem is CalendarAttachmentViewModel attachmentViewModel)
+        {
+            ViewModel?.OpenAttachmentCommand.Execute(attachmentViewModel);
+        }
+    }
+
+    private void OpenCalendarAttachment_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
+    {
+        if (sender is MenuFlyoutItem item && item.CommandParameter is CalendarAttachmentViewModel attachment)
+        {
+            ViewModel?.OpenAttachmentCommand.Execute(attachment);
+        }
+    }
+
+    private void SaveCalendarAttachment_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
+    {
+        if (sender is MenuFlyoutItem item && item.CommandParameter is CalendarAttachmentViewModel attachment)
+        {
+            ViewModel?.SaveAttachmentCommand.Execute(attachment);
+        }
+    }
 }

Wino.Core.Domain/Entities/Calendar/AccountCalendar.cs

@@ -1,6 +1,7 @@
 using System;
 using SQLite;
 using Wino.Core.Domain.Entities.Shared;
+using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 
 namespace Wino.Core.Domain.Entities.Calendar;
@@ -15,7 +16,9 @@ public class AccountCalendar : IAccountCalendar
     public string SynchronizationDeltaToken { get; set; }
     public string Name { get; set; }
     public bool IsPrimary { get; set; }
+    public bool IsSynchronizationEnabled { get; set; } = true;
     public bool IsExtended { get; set; } = true;
+    public CalendarItemShowAs DefaultShowAs { get; set; } = CalendarItemShowAs.Busy;
 
     /// <summary>
     /// Unused for now.

Wino.Core.Domain/Enums/CalendarItemUpdateSource.cs

@@ -0,0 +1,22 @@
+namespace Wino.Core.Domain.Enums;
+
+/// <summary>
+/// Indicates the source of a calendar item update.
+/// </summary>
+public enum CalendarItemUpdateSource
+{
+    /// <summary>
+    /// Update originated from client-side UI changes (ApplyUIChanges).
+    /// </summary>
+    ClientUpdated,
+
+    /// <summary>
+    /// Update originated from client-side UI revert (RevertUIChanges).
+    /// </summary>
+    ClientReverted,
+
+    /// <summary>
+    /// Update originated from server synchronization or database operations.
+    /// </summary>
+    Server
+}

Wino.Core.Domain/Interfaces/IAccountCalendar.cs

@@ -1,5 +1,6 @@
 using System;
 using Wino.Core.Domain.Entities.Shared;
+using Wino.Core.Domain.Enums;
 
 namespace Wino.Core.Domain.Interfaces;
 
@@ -9,9 +10,11 @@ public interface IAccountCalendar
     string TextColorHex { get; set; }
     string BackgroundColorHex { get; set; }
     bool IsPrimary { get; set; }
+    bool IsSynchronizationEnabled { get; set; }
     Guid AccountId { get; set; }
     string RemoteCalendarId { get; set; }
     bool IsExtended { get; set; }
+    CalendarItemShowAs DefaultShowAs { get; set; }
     Guid Id { get; set; }
     MailAccount MailAccount { get; set; }
 }

Wino.Core.ViewModels/CalendarBaseViewModel.cs

@@ -1,5 +1,7 @@
-using CommunityToolkit.Mvvm.Messaging;
+using System;
+using CommunityToolkit.Mvvm.Messaging;
 using Wino.Core.Domain.Entities.Calendar;
+using Wino.Core.Domain.Enums;
 using Wino.Messaging.Client.Calendar;
 
 namespace Wino.Core.ViewModels;
@@ -9,14 +11,19 @@ public class CalendarBaseViewModel : CoreBaseViewModel,
     IRecipient<CalendarItemUpdated>,
     IRecipient<CalendarItemDeleted>
 {
-    public void Receive(CalendarItemAdded message) => OnCalendarItemAdded(message.CalendarItem);
+    public void Receive(CalendarItemAdded message) => DispatchToUIThread(() => OnCalendarItemAdded(message.CalendarItem));
-    public void Receive(CalendarItemUpdated message) => OnCalendarItemUpdated(message.CalendarItem);
+    public void Receive(CalendarItemUpdated message) => DispatchToUIThread(() => OnCalendarItemUpdated(message.CalendarItem, message.Source));
-    public void Receive(CalendarItemDeleted message) => OnCalendarItemDeleted(message.CalendarItem);
+    public void Receive(CalendarItemDeleted message) => DispatchToUIThread(() => OnCalendarItemDeleted(message.CalendarItem));
 
     protected virtual void OnCalendarItemAdded(CalendarItem calendarItem) { }
-    protected virtual void OnCalendarItemUpdated(CalendarItem calendarItem) { }
+    protected virtual void OnCalendarItemUpdated(CalendarItem calendarItem, CalendarItemUpdateSource source) { }
     protected virtual void OnCalendarItemDeleted(CalendarItem calendarItem) { }
 
+    private void DispatchToUIThread(Action action)
+    {
+        _ = ExecuteUIThread(action);
+    }
+
     protected override void RegisterRecipients()
     {
         base.RegisterRecipients();
@@ -35,3 +42,4 @@ public class CalendarBaseViewModel : CoreBaseViewModel,
         Messenger.Unregister<CalendarItemDeleted>(this);
     }
 }
+

Wino.Core.ViewModels/CoreBaseViewModel.cs

@@ -40,7 +40,18 @@ public class CoreBaseViewModel : ObservableRecipient, INavigationAware
 
     public virtual void OnPageLoaded() { }
 
-    public async Task ExecuteUIThread(Action action) => await Dispatcher?.ExecuteOnUIThread(action);
+    public Task ExecuteUIThread(Action action)
+    {
+        if (action == null) return Task.CompletedTask;
+
+        if (Dispatcher == null)
+        {
+            action();
+            return Task.CompletedTask;
+        }
+
+        return Dispatcher.ExecuteOnUIThread(action);
+    }
     public void ReportUIChange<TMessage>(TMessage message) where TMessage : class, IUIMessage => Messenger.Send(message);
 
     protected virtual void OnDispatcherAssigned() { }

Wino.Core/Extensions/GoogleIntegratorExtensions.cs

@@ -141,6 +141,7 @@ public static class GoogleIntegratorExtensions
             Id = Guid.NewGuid(),
             TimeZone = calendarListEntry.TimeZone,
             IsPrimary = calendarListEntry.Primary.GetValueOrDefault(),
+            IsSynchronizationEnabled = true,
         };
 
         // Bg color must present. Generate one if doesnt exists.

Wino.Core/Extensions/OutlookIntegratorExtensions.cs

@@ -183,6 +183,7 @@ public static class OutlookIntegratorExtensions
             RemoteCalendarId = outlookCalendar.Id,
             IsPrimary = outlookCalendar.IsDefaultCalendar.GetValueOrDefault(),
             Name = outlookCalendar.Name,
+            IsSynchronizationEnabled = true,
             IsExtended = true,
         };
 

Wino.Core/Requests/Calendar/AcceptEventRequest.cs

@@ -27,13 +27,13 @@ public record AcceptEventRequest(CalendarItem Item, string ResponseMessage = nul
         Item.Status = CalendarItemStatus.Accepted;
         
         // Notify UI that the event status was updated
-        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item, CalendarItemUpdateSource.ClientUpdated));
     }
 
     public override void RevertUIChanges()
     {
         // If acceptance fails, revert to the previous status
         Item.Status = _previousStatus;
-        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item, CalendarItemUpdateSource.ClientReverted));
     }
 }

Wino.Core/Requests/Calendar/DeclineEventRequest.cs

@@ -27,13 +27,13 @@ public record DeclineEventRequest(CalendarItem Item, string ResponseMessage = nu
         Item.Status = CalendarItemStatus.Cancelled;
 
         // Notify UI that the event status was updated
-        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item, CalendarItemUpdateSource.ClientUpdated));
     }
 
     public override void RevertUIChanges()
     {
         // If decline fails, revert to the previous status
         Item.Status = _previousStatus;
-        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item, CalendarItemUpdateSource.ClientReverted));
     }
 }

Wino.Core/Requests/Calendar/TentativeEventRequest.cs

@@ -27,13 +27,13 @@ public record TentativeEventRequest(CalendarItem Item, string ResponseMessage =
         Item.Status = CalendarItemStatus.Tentative;
         
         // Notify UI that the event status was updated
-        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item, CalendarItemUpdateSource.ClientUpdated));
     }
 
     public override void RevertUIChanges()
     {
         // If tentative acceptance fails, revert to the previous status
         Item.Status = _previousStatus;
-        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item, CalendarItemUpdateSource.ClientReverted));
     }
 }

Wino.Core/Requests/Calendar/UpdateCalendarEventRequest.cs

@@ -33,7 +33,7 @@ public record UpdateCalendarEventRequest(CalendarItem Item, List<CalendarEventAt
     public override void ApplyUIChanges()
     {
         // Notify UI that the event was updated locally
-        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+        WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item, CalendarItemUpdateSource.ClientUpdated));
     }
 
     public override void RevertUIChanges()
@@ -42,12 +42,12 @@ public record UpdateCalendarEventRequest(CalendarItem Item, List<CalendarEventAt
         if (OriginalItem != null && OriginalAttendees != null)
         {
             // Send the original item back to restore UI state
-            WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(OriginalItem));
+            WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(OriginalItem, CalendarItemUpdateSource.ClientReverted));
         }
         else
         {
             // Fallback: just notify with current item to trigger refresh
-            WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item));
+            WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(Item, CalendarItemUpdateSource.ClientReverted));
         }
     }
 }

Wino.Core/Synchronizers/GmailSynchronizer.cs

@@ -484,7 +484,9 @@ public class GmailSynchronizer : WinoSynchronizer<IClientServiceRequest, Message
 
         _logger.Debug("Is initial synchronization: {IsInitialSync}", isInitialSync);
 
-        var localCalendars = await _gmailChangeProcessor.GetAccountCalendarsAsync(Account.Id).ConfigureAwait(false);
+        var localCalendars = (await _gmailChangeProcessor.GetAccountCalendarsAsync(Account.Id).ConfigureAwait(false))
+            .Where(c => c.IsSynchronizationEnabled)
+            .ToList();
 
         // TODO: Better logging and exception handling.
         foreach (var calendar in localCalendars)
@@ -566,6 +568,7 @@ public class GmailSynchronizer : WinoSynchronizer<IClientServiceRequest, Message
         }
 
         var localCalendars = await _gmailChangeProcessor.GetAccountCalendarsAsync(Account.Id).ConfigureAwait(false);
+        var remotePrimaryCalendarId = GetPrimaryCalendarId(calendarListResponse.Items);
 
         List<AccountCalendar> insertedCalendars = new();
         List<AccountCalendar> updatedCalendars = new();
@@ -596,14 +599,21 @@ public class GmailSynchronizer : WinoSynchronizer<IClientServiceRequest, Message
             {
                 // Insert new calendar.
                 var localCalendar = calendar.AsCalendar(Account.Id);
+                localCalendar.IsPrimary = string.Equals(localCalendar.RemoteCalendarId, remotePrimaryCalendarId, StringComparison.OrdinalIgnoreCase);
                 insertedCalendars.Add(localCalendar);
             }
             else
             {
                 // Update existing calendar. Right now we only update the name.
-                if (ShouldUpdateCalendar(calendar, existingLocalCalendar))
+                if (ShouldUpdateCalendar(calendar, existingLocalCalendar, remotePrimaryCalendarId))
                 {
                     existingLocalCalendar.Name = calendar.Summary;
+                    existingLocalCalendar.TimeZone = calendar.TimeZone;
+                    if (!string.IsNullOrEmpty(calendar.BackgroundColor))
+                        existingLocalCalendar.BackgroundColorHex = calendar.BackgroundColor;
+                    if (!string.IsNullOrEmpty(calendar.ForegroundColor))
+                        existingLocalCalendar.TextColorHex = calendar.ForegroundColor;
+                    existingLocalCalendar.IsPrimary = string.Equals(existingLocalCalendar.RemoteCalendarId, remotePrimaryCalendarId, StringComparison.OrdinalIgnoreCase);
 
                     updatedCalendars.Add(existingLocalCalendar);
                 }
@@ -770,14 +780,41 @@ public class GmailSynchronizer : WinoSynchronizer<IClientServiceRequest, Message
         }
     }
 
-    private bool ShouldUpdateCalendar(CalendarListEntry calendarListEntry, AccountCalendar accountCalendar)
+    private bool ShouldUpdateCalendar(CalendarListEntry calendarListEntry, AccountCalendar accountCalendar, string remotePrimaryCalendarId)
     {
-        // TODO: Only calendar name is updated for now. We can add more checks here.
-
         var remoteCalendarName = calendarListEntry.Summary;
-        var localCalendarName = accountCalendar.Name;
+        var remoteTimeZone = calendarListEntry.TimeZone;
+        var remoteBackgroundColor = string.IsNullOrEmpty(calendarListEntry.BackgroundColor) ? accountCalendar.BackgroundColorHex : calendarListEntry.BackgroundColor;
+        var remoteTextColor = string.IsNullOrEmpty(calendarListEntry.ForegroundColor) ? accountCalendar.TextColorHex : calendarListEntry.ForegroundColor;
+        var remoteIsPrimary = string.Equals(calendarListEntry.Id, remotePrimaryCalendarId, StringComparison.OrdinalIgnoreCase);
 
-        return !localCalendarName.Equals(remoteCalendarName, StringComparison.OrdinalIgnoreCase);
+        bool isNameChanged = !string.Equals(accountCalendar.Name, remoteCalendarName, StringComparison.OrdinalIgnoreCase);
+        bool isTimeZoneChanged = !string.Equals(accountCalendar.TimeZone, remoteTimeZone, StringComparison.OrdinalIgnoreCase);
+        bool isBackgroundColorChanged = !string.Equals(accountCalendar.BackgroundColorHex, remoteBackgroundColor, StringComparison.OrdinalIgnoreCase);
+        bool isTextColorChanged = !string.Equals(accountCalendar.TextColorHex, remoteTextColor, StringComparison.OrdinalIgnoreCase);
+        bool isPrimaryChanged = accountCalendar.IsPrimary != remoteIsPrimary;
+
+        return isNameChanged || isTimeZoneChanged || isBackgroundColorChanged || isTextColorChanged || isPrimaryChanged;
+    }
+
+    private string GetPrimaryCalendarId(IList<CalendarListEntry> remoteCalendars)
+    {
+        if (remoteCalendars == null || remoteCalendars.Count == 0)
+            return string.Empty;
+
+        var explicitPrimary = remoteCalendars.FirstOrDefault(c => c.Primary.GetValueOrDefault());
+        if (explicitPrimary != null)
+            return explicitPrimary.Id;
+
+        var byPrimaryKeyword = remoteCalendars.FirstOrDefault(c => string.Equals(c.Id, "primary", StringComparison.OrdinalIgnoreCase));
+        if (byPrimaryKeyword != null)
+            return byPrimaryKeyword.Id;
+
+        var byAccountAddress = remoteCalendars.FirstOrDefault(c => string.Equals(c.Id, Account.Address, StringComparison.OrdinalIgnoreCase));
+        if (byAccountAddress != null)
+            return byAccountAddress.Id;
+
+        return remoteCalendars.First().Id;
     }
 
     private bool ShouldUpdateFolder(Label remoteFolder, MailItemFolder existingLocalFolder)

Wino.Core/Synchronizers/OutlookSynchronizer.cs

@@ -1961,7 +1961,9 @@ public class OutlookSynchronizer : WinoSynchronizer<RequestInformation, Message,
 
         await SynchronizeCalendarsAsync(cancellationToken).ConfigureAwait(false);
 
-        var localCalendars = await _outlookChangeProcessor.GetAccountCalendarsAsync(Account.Id).ConfigureAwait(false);
+        var localCalendars = (await _outlookChangeProcessor.GetAccountCalendarsAsync(Account.Id).ConfigureAwait(false))
+            .Where(c => c.IsSynchronizationEnabled)
+            .ToList();
 
         Microsoft.Graph.Me.Calendars.Item.CalendarView.Delta.DeltaGetResponse eventsDeltaResponse = null;
 
@@ -2078,6 +2080,7 @@ public class OutlookSynchronizer : WinoSynchronizer<RequestInformation, Message,
     private async Task SynchronizeCalendarsAsync(CancellationToken cancellationToken = default)
     {
         var calendars = await _graphClient.Me.Calendars.GetAsync(cancellationToken: cancellationToken).ConfigureAwait(false);
+        var remotePrimaryCalendarId = await GetPrimaryCalendarIdAsync(calendars.Value, cancellationToken).ConfigureAwait(false);
 
         var localCalendars = await _outlookChangeProcessor.GetAccountCalendarsAsync(Account.Id).ConfigureAwait(false);
 
@@ -2110,14 +2113,18 @@ public class OutlookSynchronizer : WinoSynchronizer<RequestInformation, Message,
             {
                 // Insert new calendar.
                 var localCalendar = calendar.AsCalendar(Account);
+                localCalendar.IsPrimary = string.Equals(localCalendar.RemoteCalendarId, remotePrimaryCalendarId, StringComparison.OrdinalIgnoreCase);
                 insertedCalendars.Add(localCalendar);
             }
             else
             {
                 // Update existing calendar. Right now we only update the name.
-                if (ShouldUpdateCalendar(calendar, existingLocalCalendar))
+                if (ShouldUpdateCalendar(calendar, existingLocalCalendar, remotePrimaryCalendarId))
                 {
                     existingLocalCalendar.Name = calendar.Name;
+                    existingLocalCalendar.IsPrimary = string.Equals(existingLocalCalendar.RemoteCalendarId, remotePrimaryCalendarId, StringComparison.OrdinalIgnoreCase);
+                    if (!string.IsNullOrEmpty(calendar.HexColor))
+                        existingLocalCalendar.BackgroundColorHex = calendar.HexColor;
 
                     updatedCalendars.Add(existingLocalCalendar);
                 }
@@ -2147,14 +2154,40 @@ public class OutlookSynchronizer : WinoSynchronizer<RequestInformation, Message,
         }
     }
 
-    private bool ShouldUpdateCalendar(Calendar calendar, AccountCalendar accountCalendar)
+    private bool ShouldUpdateCalendar(Calendar calendar, AccountCalendar accountCalendar, string remotePrimaryCalendarId)
     {
-        // TODO: Only calendar name is updated for now. We can add more checks here.
-
         var remoteCalendarName = calendar.Name;
-        var localCalendarName = accountCalendar.Name;
+        var remoteBackgroundColor = string.IsNullOrEmpty(calendar.HexColor) ? accountCalendar.BackgroundColorHex : calendar.HexColor;
+        var remoteIsPrimary = string.Equals(calendar.Id, remotePrimaryCalendarId, StringComparison.OrdinalIgnoreCase);
 
-        return !localCalendarName.Equals(remoteCalendarName, StringComparison.OrdinalIgnoreCase);
+        bool isNameChanged = !string.Equals(accountCalendar.Name, remoteCalendarName, StringComparison.OrdinalIgnoreCase);
+        bool isBackgroundColorChanged = !string.Equals(accountCalendar.BackgroundColorHex, remoteBackgroundColor, StringComparison.OrdinalIgnoreCase);
+        bool isPrimaryChanged = accountCalendar.IsPrimary != remoteIsPrimary;
+
+        return isNameChanged || isBackgroundColorChanged || isPrimaryChanged;
+    }
+
+    private async Task<string> GetPrimaryCalendarIdAsync(IList<Calendar> remoteCalendars, CancellationToken cancellationToken)
+    {
+        if (remoteCalendars == null || remoteCalendars.Count == 0)
+            return string.Empty;
+
+        var explicitPrimary = remoteCalendars.FirstOrDefault(c => c.IsDefaultCalendar.GetValueOrDefault());
+        if (explicitPrimary != null)
+            return explicitPrimary.Id;
+
+        try
+        {
+            var meCalendar = await _graphClient.Me.Calendar.GetAsync(cancellationToken: cancellationToken).ConfigureAwait(false);
+            if (!string.IsNullOrEmpty(meCalendar?.Id))
+                return meCalendar.Id;
+        }
+        catch (Exception ex)
+        {
+            _logger.Warning(ex, "Failed to fetch default Outlook calendar for {Name}. Falling back to first available calendar.", Account.Name);
+        }
+
+        return remoteCalendars.First().Id;
     }
 
     #region Calendar Operations

Wino.Mail.ViewModels/AccountDetailsPageViewModel.cs

@@ -26,6 +26,7 @@ public partial class AccountDetailsPageViewModel : MailBaseViewModel
     private readonly IAccountService _accountService;
     private readonly IFolderService _folderService;
     private readonly ICalendarService _calendarService;
+    private readonly IStatePersistanceService _statePersistanceService;
     private bool isLoaded = false;
 
     public MailAccount Account { get; set; }
@@ -60,12 +61,14 @@ public partial class AccountDetailsPageViewModel : MailBaseViewModel
     public AccountDetailsPageViewModel(IMailDialogService dialogService,
         IAccountService accountService,
         IFolderService folderService,
-        ICalendarService calendarService)
+        ICalendarService calendarService,
+        IStatePersistanceService statePersistanceService)
     {
         _dialogService = dialogService;
         _accountService = accountService;
         _folderService = folderService;
         _calendarService = calendarService;
+        _statePersistanceService = statePersistanceService;
     }
 
     [RelayCommand]
@@ -132,6 +135,8 @@ public partial class AccountDetailsPageViewModel : MailBaseViewModel
 
             OnPropertyChanged(nameof(IsFocusedInboxSupportedForAccount));
 
+            SelectedTabIndex = _statePersistanceService.ApplicationMode == WinoApplicationMode.Calendar ? 2 : 1;
+
             var folderStructures = (await _folderService.GetFolderStructureForAccountAsync(Account.Id, true)).Folders;
 
             foreach (var folder in folderStructures)

Wino.Mail.WinUI/Services/AccountCalendarStateService.cs

@@ -225,6 +225,8 @@ public partial class AccountCalendarStateService : ObservableRecipient,
                     existingCalendar.BackgroundColorHex = accountCalendar.BackgroundColorHex;
                     existingCalendar.IsExtended = accountCalendar.IsExtended;
                     existingCalendar.IsPrimary = accountCalendar.IsPrimary;
+                    existingCalendar.IsSynchronizationEnabled = accountCalendar.IsSynchronizationEnabled;
+                    existingCalendar.DefaultShowAs = accountCalendar.DefaultShowAs;
                 }
             });
         }
@@ -241,6 +243,8 @@ public partial class AccountCalendarStateService : ObservableRecipient,
                 existingCalendar.BackgroundColorHex = accountCalendar.BackgroundColorHex;
                 existingCalendar.IsExtended = accountCalendar.IsExtended;
                 existingCalendar.IsPrimary = accountCalendar.IsPrimary;
+                existingCalendar.IsSynchronizationEnabled = accountCalendar.IsSynchronizationEnabled;
+                existingCalendar.DefaultShowAs = accountCalendar.DefaultShowAs;
             }
         }
     }

Wino.Mail.WinUI/Views/Account/AccountDetailsPage.xaml.cs

@@ -51,8 +51,13 @@ public sealed partial class AccountDetailsPage : AccountDetailsPageAbstract
 
         if (e.NavigationMode == NavigationMode.New)
         {
-            // Set initial tab to Mail (index 1)
+            var targetTabIndex = ViewModel.SelectedTabIndex;
-            TabSelector.SelectedItem = TabSelector.Items[1];
+            if (targetTabIndex < 0 || targetTabIndex >= TabSelector.Items.Count)
+            {
+                targetTabIndex = 1;
+            }
+
+            TabSelector.SelectedItem = TabSelector.Items[targetTabIndex];
         }
     }
 }

Wino.Mail.WinUI/Views/Calendar/EventDetailsPage.xaml.cs

@@ -2,6 +2,7 @@ using System;
 using System.Text.Json;
 using System.Threading.Tasks;
 using CommunityToolkit.Mvvm.Messaging;
+using CommunityToolkit.WinUI;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Navigation;
@@ -77,6 +78,12 @@ public sealed partial class EventDetailsPage : EventDetailsPageAbstract,
 
     private async Task RenderDescriptionAsync()
     {
+        if (DispatcherQueue != null && !DispatcherQueue.HasThreadAccess)
+        {
+            await DispatcherQueue.EnqueueAsync(RenderDescriptionAsync);
+            return;
+        }
+
         if (ViewModel?.CurrentEvent?.CalendarItem == null)
             return;
 
@@ -141,6 +148,12 @@ public sealed partial class EventDetailsPage : EventDetailsPageAbstract,
 
     private async Task UpdateEditorThemeAsync()
     {
+        if (DispatcherQueue != null && !DispatcherQueue.HasThreadAccess)
+        {
+            await DispatcherQueue.EnqueueAsync(UpdateEditorThemeAsync);
+            return;
+        }
+
         await DOMLoadedTask.Task;
 
         if (ViewModel.IsDarkWebviewRenderer)
@@ -171,9 +184,9 @@ public sealed partial class EventDetailsPage : EventDetailsPageAbstract,
         _ = UpdateEditorThemeAsync();
     }
 
-    async void IRecipient<CalendarDescriptionRenderingRequested>.Receive(CalendarDescriptionRenderingRequested message)
+    void IRecipient<CalendarDescriptionRenderingRequested>.Receive(CalendarDescriptionRenderingRequested message)
     {
-        await RenderDescriptionAsync();
+        _ = RenderDescriptionAsync();
     }
 
     protected override void RegisterRecipients()

Wino.Messages/Client/Calendar/CalendarItemEventMessages.cs

@@ -1,7 +1,8 @@
-using Wino.Core.Domain.Entities.Calendar;
+using Wino.Core.Domain.Entities.Calendar;
+using Wino.Core.Domain.Enums;
 
 namespace Wino.Messaging.Client.Calendar;
 
 public record CalendarItemAdded(CalendarItem CalendarItem);
-public record CalendarItemUpdated(CalendarItem CalendarItem);
+public record CalendarItemUpdated(CalendarItem CalendarItem, CalendarItemUpdateSource Source);
 public record CalendarItemDeleted(CalendarItem CalendarItem);

Wino.Services/CalendarService.cs

@@ -144,7 +144,7 @@ public class CalendarService : BaseDatabaseService, ICalendarService
                 }
             });
 
-            WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(calendarItem));
+            WeakReferenceMessenger.Default.Send(new CalendarItemUpdated(calendarItem, CalendarItemUpdateSource.Server));
         }
         catch (Exception ex)
         {

Wino.Services/DatabaseService.cs

@@ -64,4 +64,5 @@ public class DatabaseService : IDatabaseService
             Connection.CreateTableAsync<MailInvitationCalendarMapping>()
             );
     }
+
 }