Some event selections

Wino.Calendar.ViewModels/AccountManagementViewModel.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 using CommunityToolkit.Mvvm.Input;
@@ -141,6 +142,16 @@ public partial class AccountManagementViewModel : AccountManagementPageViewModel
             Type = CalendarSynchronizationType.CalendarMetadata
         };
 
+        var timer = new Stopwatch();
+
         var synchronizationResponse = await WinoServerConnectionManager.GetResponseAsync<CalendarSynchronizationResult, NewCalendarSynchronizationRequested>(new NewCalendarSynchronizationRequested(synchronizationOptions, SynchronizationSource.Client));
+
+        timer.Stop();
+
+        Debug.WriteLine("Synchronization completed in {timer.ElapsedMilliseconds} ms");
+
+        // TODO: Properly handle synchronization errors.
+
+        accountCreationDialog.Complete(false);
     }
 }

Wino.Calendar.ViewModels/CalendarPageViewModel.cs

@@ -127,6 +127,7 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
     private readonly ICalendarService _calendarService;
     private readonly INavigationService _navigationService;
     private readonly IKeyPressService _keyPressService;
+    private readonly ICalendarServiceEx _calendarServiceEx;
     private readonly IPreferencesService _preferencesService;
 
     // Store latest rendered options.
@@ -146,6 +147,7 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
                                  ICalendarService calendarService,
                                  INavigationService navigationService,
                                  IKeyPressService keyPressService,
+                                 ICalendarServiceEx calendarServiceEx,
                                  IAccountCalendarStateService accountCalendarStateService,
                                  IPreferencesService preferencesService)
     {
@@ -155,6 +157,7 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
         _calendarService = calendarService;
         _navigationService = navigationService;
         _keyPressService = keyPressService;
+        _calendarServiceEx = calendarServiceEx;
         _preferencesService = preferencesService;
 
         AccountCalendarStateService.AccountCalendarSelectionStateChanged += UpdateAccountCalendarRequested;
@@ -235,23 +238,6 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
     [RelayCommand(AllowConcurrentExecutions = false, CanExecute = nameof(CanSaveQuickEvent))]
     private async Task SaveQuickEventAsync()
     {
-        var durationSeconds = (QuickEventEndTime - QuickEventStartTime).TotalSeconds;
-
-        var testCalendarItem = new CalendarItem
-        {
-            CalendarId = SelectedQuickEventAccountCalendar.Id,
-            StartDate = QuickEventStartTime,
-            DurationInSeconds = durationSeconds,
-            CreatedAt = DateTime.UtcNow,
-            Description = string.Empty,
-            Location = Location,
-            Title = EventName,
-            Id = Guid.NewGuid()
-        };
-
-        IsQuickEventDialogOpen = false;
-        await _calendarService.CreateNewCalendarItemAsync(testCalendarItem, null);
-
         // TODO: Create the request with the synchronizer.
     }
 
@@ -635,10 +621,13 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
             // Check all the events for the given date range and calendar.
             // Then find the day representation for all the events returned, and add to the collection.
 
-            var events = await _calendarService.GetCalendarEventsAsync(calendarViewModel, dayRangeRenderModel).ConfigureAwait(false);
+            var events = await _calendarServiceEx.GetExpandedEventsInDateRangeWithExceptionsAsync(dayRangeRenderModel.Period.Start, dayRangeRenderModel.Period.End, calendarViewModel.AccountCalendar).ConfigureAwait(false);
 
             foreach (var @event in events)
             {
+                // TODO: Do it in the service.
+                @event.AssignedCalendar = calendarViewModel.AccountCalendar;
+
                 // Find the days that the event falls into.
                 var allDaysForEvent = dayRangeRenderModel.CalendarDays.Where(a => a.Period.OverlapsWith(@event.Period));
 
@@ -800,12 +789,12 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
         // Recurring events must be selected as a single instance.
         // We need to find the day that the event is in, and then select the event.
 
-        if (!calendarItemViewModel.IsRecurringEvent)
-        {
-            return [calendarItemViewModel];
-        }
-        else
-        {
+        if (calendarItemViewModel == null) return Enumerable.Empty<CalendarItemViewModel>();
+
+        // If the calendar item is not recurring, we can just return it.
+
+        if (calendarItemViewModel.ItemType == CalendarItemType.Timed || calendarItemViewModel.ItemType == CalendarItemType.RecurringException) return new[] { calendarItemViewModel };
+
         return DayRanges
             .SelectMany(a => a.CalendarDays)
             .Select(b => b.EventsCollection.GetCalendarItem(calendarItemViewModel.Id))
@@ -813,7 +802,6 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
             .Cast<CalendarItemViewModel>()
             .Distinct();
     }
-    }
 
     private void UnselectCalendarItem(CalendarItemViewModel calendarItemViewModel, CalendarDayModel calendarDay = null)
     {
@@ -821,6 +809,8 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
 
         var itemsToUnselect = GetCalendarItems(calendarItemViewModel, calendarDay);
 
+        if (itemsToUnselect == null) return;
+
         foreach (var item in itemsToUnselect)
         {
             item.IsSelected = false;
@@ -833,6 +823,8 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
 
         var itemsToSelect = GetCalendarItems(calendarItemViewModel, calendarDay);
 
+        if (itemsToSelect == null) return;
+
         foreach (var item in itemsToSelect)
         {
             item.IsSelected = true;

Wino.Calendar.ViewModels/Data/CalendarItemViewModel.cs

@@ -1,8 +1,10 @@
 using System;
 using System.Collections.ObjectModel;
+using System.Diagnostics;
 using CommunityToolkit.Mvvm.ComponentModel;
 using Itenso.TimePeriod;
 using Wino.Core.Domain.Entities.Calendar;
+using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 
 namespace Wino.Calendar.ViewModels.Data;
@@ -17,28 +19,73 @@ public partial class CalendarItemViewModel : ObservableObject, ICalendarItem, IC
 
     public IAccountCalendar AssignedCalendar => CalendarItem.AssignedCalendar;
 
-    public DateTime StartDate { get => CalendarItem.StartDate; set => CalendarItem.StartDate = value; }
+    public DateTime StartDateTime { get => CalendarItem.StartDateTime; set => CalendarItem.StartDateTime = value; }
 
-    public DateTime EndDate => CalendarItem.EndDate;
+    public DateTime EndDateTime => CalendarItem.EndDateTime;
 
-    public double DurationInSeconds { get => CalendarItem.DurationInSeconds; set => CalendarItem.DurationInSeconds = value; }
+    /// <summary>
+    /// Gets the start date and time in the local time zone for display purposes.
+    /// </summary>
+    public DateTime LocalStartDateTime => ConvertToLocalTime();
+
+    /// <summary>
+    /// Gets the end date and time in the local time zone for display purposes.
+    /// </summary>
+    public DateTime LocalEndDateTime => ConvertToLocalTime();
 
     public ITimePeriod Period => CalendarItem.Period;
 
-    public bool IsAllDayEvent => CalendarItem.IsAllDayEvent;
-    public bool IsMultiDayEvent => CalendarItem.IsMultiDayEvent;
-    public bool IsRecurringEvent => CalendarItem.IsRecurringEvent;
-    public bool IsRecurringChild => CalendarItem.IsRecurringChild;
-    public bool IsRecurringParent => CalendarItem.IsRecurringParent;
+    public bool IsRecurringEvent => !string.IsNullOrEmpty(CalendarItem.RecurrenceRules) || !string.IsNullOrEmpty(CalendarItem.RecurringEventId);
 
     [ObservableProperty]
     private bool _isSelected;
 
     public ObservableCollection<CalendarEventAttendee> Attendees { get; } = new ObservableCollection<CalendarEventAttendee>();
 
+    public CalendarItemType ItemType => CalendarItem.ItemType;
+
     public CalendarItemViewModel(CalendarItem calendarItem)
     {
         CalendarItem = calendarItem;
+
+        Debug.WriteLine($"{Title} : {ItemType}");
+    }
+
+    /// <summary>
+    /// Converts a DateTime to local time based on the provided timezone.
+    /// If timezone is empty or null, assumes the DateTime is in UTC.
+    /// </summary>
+    /// <param name="dateTime">The DateTime to convert</param>
+    /// <param name="timeZone">The timezone string. If empty/null, assumes UTC.</param>
+    /// <returns>DateTime converted to local time</returns>
+    private DateTime ConvertToLocalTime()
+    {
+        // All day events ignore time zones and are treated as local time.
+        if (ItemType == CalendarItemType.AllDay || ItemType == CalendarItemType.MultiDayAllDay || ItemType == CalendarItemType.RecurringAllDay)
+            return CalendarItem.StartDateTime;
+
+        if (string.IsNullOrEmpty(CalendarItem.TimeZone))
+        {
+            // If no timezone specified, assume it's UTC and convert to local time
+            return DateTime.SpecifyKind(CalendarItem.StartDateTime, DateTimeKind.Utc).ToLocalTime();
+        }
+
+        try
+        {
+            // Parse the timezone and convert to local time
+            var sourceTimeZone = TimeZoneInfo.FindSystemTimeZoneById(CalendarItem.TimeZone);
+            return TimeZoneInfo.ConvertTimeToUtc(CalendarItem.StartDateTime, sourceTimeZone).ToLocalTime();
+        }
+        catch (TimeZoneNotFoundException)
+        {
+            // If timezone is not found, fallback to treating as UTC
+            return DateTime.SpecifyKind(CalendarItem.StartDateTime, DateTimeKind.Utc).ToLocalTime();
+        }
+        catch (InvalidTimeZoneException)
+        {
+            // If timezone is invalid, fallback to treating as UTC
+            return DateTime.SpecifyKind(CalendarItem.StartDateTime, DateTimeKind.Utc).ToLocalTime();
+        }
     }
 
     public override string ToString() => CalendarItem.Title;

Wino.Calendar.ViewModels/EventDetailsPageViewModel.cs

@@ -31,7 +31,7 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
     [ObservableProperty]
     private CalendarItemViewModel _seriesParent;
 
-    public bool CanViewSeries => CurrentEvent?.IsRecurringChild ?? false;
+    public bool CanViewSeries => false; //CurrentEvent?.IsRecurringChild ?? false; // TODO: Implement this properly
 
     #endregion
 
@@ -67,7 +67,7 @@ public partial class EventDetailsPageViewModel : CalendarBaseViewModel
 
             CurrentEvent = new CalendarItemViewModel(currentEventItem);
 
-            var attendees = await _calendarService.GetAttendeesAsync(currentEventItem.EventTrackingId);
+            var attendees = await _calendarService.GetAttendeesAsync(currentEventItem.Id);
 
             foreach (var item in attendees)
             {

Wino.Calendar/Controls/CalendarItemControl.xaml

@@ -69,7 +69,7 @@
             VerticalAlignment="Top"
             Orientation="Horizontal"
             Spacing="6">
-            <controls:WinoFontIcon
+            <!--<controls:WinoFontIcon
                 FontSize="12"
                 Foreground="{x:Bind helpers:XamlHelpers.GetReadableTextColor(CalendarItem.AssignedCalendar.BackgroundColorHex), Mode=OneWay}"
                 Icon="CalendarEventRepeat"
@@ -79,7 +79,7 @@
                 FontSize="12"
                 Foreground="{x:Bind helpers:XamlHelpers.GetReadableTextColor(CalendarItem.AssignedCalendar.BackgroundColorHex), Mode=OneWay}"
                 Icon="CalendarEventMuiltiDay"
-                Visibility="{x:Bind CalendarItem.IsMultiDayEvent, Mode=OneWay}" />
+                Visibility="{x:Bind CalendarItem.IsMultiDayEvent, Mode=OneWay}" />-->
         </StackPanel>
 
         <VisualStateManager.VisualStateGroups>

Wino.Calendar/Controls/CalendarItemControl.xaml.cs

@@ -7,6 +7,7 @@ using Windows.UI.Xaml.Input;
 using Wino.Calendar.ViewModels.Data;
 using Wino.Calendar.ViewModels.Messages;
 using Wino.Core.Domain;
+using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Models.Calendar;
 
 namespace Wino.Calendar.Controls;
@@ -90,7 +91,9 @@ public sealed partial class CalendarItemControl : UserControl
         if (CalendarItem == null) return;
         if (DisplayingDate == null) return;
 
-        if (CalendarItem.IsMultiDayEvent)
+        bool isMultiDayEvent = CalendarItem.CalendarItem.ItemType == CalendarItemType.MultiDay || CalendarItem.CalendarItem.ItemType == CalendarItemType.MultiDayAllDay;
+
+        if (isMultiDayEvent)
         {
             // Multi day events are divided into 3 categories:
             // 1. All day events
@@ -103,14 +106,14 @@ public sealed partial class CalendarItemControl : UserControl
                 periodRelation == PeriodRelation.EnclosingStartTouching)
             {
                 // hour -> title
-                CalendarItemTitle = $"{DisplayingDate.CalendarRenderOptions.CalendarSettings.GetTimeString(CalendarItem.StartDate.TimeOfDay)} -> {CalendarItem.Title}";
+                CalendarItemTitle = $"{DisplayingDate.CalendarRenderOptions.CalendarSettings.GetTimeString(CalendarItem.StartDateTime.TimeOfDay)} -> {CalendarItem.Title}";
             }
             else if (
                 periodRelation == PeriodRelation.EndInside ||
                 periodRelation == PeriodRelation.EnclosingEndTouching)
             {
                 // title <- hour
-                CalendarItemTitle = $"{CalendarItem.Title} <- {DisplayingDate.CalendarRenderOptions.CalendarSettings.GetTimeString(CalendarItem.EndDate.TimeOfDay)}";
+                CalendarItemTitle = $"{CalendarItem.Title} <- {DisplayingDate.CalendarRenderOptions.CalendarSettings.GetTimeString(CalendarItem.EndDateTime.TimeOfDay)}";
             }
             else if (periodRelation == PeriodRelation.Enclosing)
             {
@@ -139,11 +142,11 @@ public sealed partial class CalendarItemControl : UserControl
     {
         if (CalendarItem == null) return;
 
-        if (CalendarItem.IsAllDayEvent)
+        if (CalendarItem.CalendarItem.ItemType == CalendarItemType.AllDay)
         {
             VisualStateManager.GoToState(this, "AllDayEvent", true);
         }
-        else if (CalendarItem.IsMultiDayEvent)
+        else if (CalendarItem.CalendarItem.ItemType == CalendarItemType.MultiDayAllDay || CalendarItem.CalendarItem.ItemType == CalendarItemType.MultiDay)
         {
             if (IsCustomEventArea)
             {

Wino.Calendar/Controls/WinoCalendarPanel.cs

@@ -9,6 +9,7 @@ using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Wino.Calendar.Models;
 using Wino.Calendar.ViewModels.Data;
+using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 
 namespace Wino.Calendar.Controls;
@@ -44,9 +45,9 @@ public partial class WinoCalendarPanel : Panel
 
     private void ResetMeasurements() => _measurements.Clear();
 
-    private double GetChildTopMargin(ICalendarItem calendarItemViewModel, double availableHeight)
+    private double GetChildTopMargin(ICalendarItemViewModel calendarItemViewModel, double availableHeight)
     {
-        var childStart = calendarItemViewModel.StartDate;
+        var childStart = calendarItemViewModel.LocalStartDateTime;
 
         if (childStart <= Period.Start)
         {
@@ -68,10 +69,10 @@ public partial class WinoCalendarPanel : Panel
     private double GetChildLeftMargin(CalendarItemMeasurement calendarItemMeasurement, double availableWidth)
         => availableWidth * calendarItemMeasurement.Left;
 
-    private double GetChildHeight(ICalendarItem child)
+    private double GetChildHeight(ICalendarItemViewModel child)
     {
         // All day events are not measured.
-        if (child.IsAllDayEvent) return 0;
+        if (child.ItemType == CalendarItemType.AllDay) return 0;
 
         double childDurationInMinutes = 0d;
         double availableHeight = HourHeight * 24;
@@ -80,7 +81,7 @@ public partial class WinoCalendarPanel : Panel
 
         // Debug.WriteLine($"Render relation of {child.Title} ({child.Period.Start} - {child.Period.End}) is {periodRelation} with {Period.Start.Day}");
 
-        if (!child.IsMultiDayEvent)
+        if (child.ItemType != CalendarItemType.MultiDay || child.ItemType != CalendarItemType.MultiDayAllDay)
         {
             childDurationInMinutes = child.Period.Duration.TotalMinutes;
         }
@@ -127,7 +128,7 @@ public partial class WinoCalendarPanel : Panel
         foreach (var control in calendarControls)
         {
             // We can't arrange this child.
-            if (!(control.Content is ICalendarItem child)) continue;
+            if (!(control.Content is ICalendarItemViewModel child)) continue;
 
             bool isHorizontallyLastItem = false;
 
@@ -160,7 +161,7 @@ public partial class WinoCalendarPanel : Panel
             double extraRightMargin = 0;
 
             // Multi-day events don't have any margin and their hit test is disabled.
-            if (!child.IsMultiDayEvent)
+            if (child.ItemType != CalendarItemType.MultiDay || child.ItemType != CalendarItemType.MultiDayAllDay)
             {
                 // Max of 5% of the width or 20px max.
                 extraRightMargin = isHorizontallyLastItem ? Math.Max(LastItemRightExtraMargin, finalSize.Width * 5 / 100) : 0;
@@ -168,8 +169,10 @@ public partial class WinoCalendarPanel : Panel
 
             if (childWidth < 0) childWidth = 1;
 
+            bool isAllOrMultiDayEvent = child.ItemType == CalendarItemType.AllDay || child.ItemType == CalendarItemType.MultiDay || child.ItemType == CalendarItemType.MultiDayAllDay;
+
             // Regular events must have 2px margin
-            if (!child.IsMultiDayEvent && !child.IsAllDayEvent)
+            if (!isAllOrMultiDayEvent)
             {
                 childLeft += 2;
                 childTop += 2;
@@ -211,10 +214,12 @@ public partial class WinoCalendarPanel : Panel
         var columns = new List<List<ICalendarItem>>();
         DateTime? lastEventEnding = null;
 
-        foreach (var ev in events.OrderBy(ev => ev.StartDate).ThenBy(ev => ev.EndDate))
+        foreach (var ev in events.OrderBy(ev => ev.StartDateTime).ThenBy(ev => ev.EndDateTime))
         {
             // Multi-day events are not measured.
-            if (ev.IsMultiDayEvent) continue;
+            bool isMultiDayEvent = ev.ItemType == CalendarItemType.MultiDay || ev.ItemType == CalendarItemType.MultiDayAllDay;
+
+            if (isMultiDayEvent) continue;
 
             if (ev.Period.Start >= lastEventEnding)
             {

Wino.Calendar/Helpers/CalendarXamlHelpers.cs

@@ -22,6 +22,7 @@ public static class CalendarXamlHelpers
     /// </summary>
     public static string GetEventDetailsDateString(CalendarItemViewModel calendarItemViewModel, CalendarSettings settings)
     {
+        // TODO: This is not correct.
         if (calendarItemViewModel == null || settings == null) return string.Empty;
 
         var start = calendarItemViewModel.Period.Start;
@@ -30,7 +31,7 @@ public static class CalendarXamlHelpers
         string timeFormat = settings.DayHeaderDisplayType == DayHeaderDisplayType.TwelveHour ? "h:mm tt" : "HH:mm";
         string dateFormat = settings.DayHeaderDisplayType == DayHeaderDisplayType.TwelveHour ? "dddd, dd MMMM h:mm tt" : "dddd, dd MMMM HH:mm";
 
-        if (calendarItemViewModel.IsMultiDayEvent)
+        if (calendarItemViewModel.CalendarItem.ItemType == CalendarItemType.MultiDay || calendarItemViewModel.CalendarItem.ItemType == CalendarItemType.MultiDayAllDay)
         {
             return $"{start.ToString($"dd MMMM ddd {timeFormat}", settings.CultureInfo)} - {end.ToString($"dd MMMM ddd {timeFormat}", settings.CultureInfo)}";
         }
@@ -42,54 +43,14 @@ public static class CalendarXamlHelpers
 
     public static string GetRecurrenceString(CalendarItemViewModel calendarItemViewModel)
     {
-        if (calendarItemViewModel == null || !calendarItemViewModel.IsRecurringChild) return string.Empty;
-
-        // Parse recurrence rules
-        var calendarEvent = new CalendarEvent
-        {
-            Start = new CalDateTime(calendarItemViewModel.StartDate),
-            End = new CalDateTime(calendarItemViewModel.EndDate),
-        };
-
-        var recurrenceLines = Regex.Split(calendarItemViewModel.CalendarItem.Recurrence, Constants.CalendarEventRecurrenceRuleSeperator);
-
-        foreach (var line in recurrenceLines)
-        {
-            calendarEvent.RecurrenceRules.Add(new RecurrencePattern(line));
-        }
-
-        if (calendarEvent.RecurrenceRules == null || !calendarEvent.RecurrenceRules.Any())
-        {
-            return "No recurrence pattern.";
-        }
-
-        var recurrenceRule = calendarEvent.RecurrenceRules.First();
-        var daysOfWeek = string.Join(", ", recurrenceRule.ByDay.Select(day => day.DayOfWeek.ToString()));
-        string timeZone = calendarEvent.DtStart.TzId ?? "UTC";
-
-        return $"Every {daysOfWeek}, effective {calendarEvent.DtStart.Value.ToShortDateString()} " +
-               $"from {calendarEvent.DtStart.Value.ToShortTimeString()} to {calendarEvent.DtEnd.Value.ToShortTimeString()} " +
-               $"{timeZone}.";
+        // TODO
+        return string.Empty;
     }
 
     public static string GetDetailsPopupDurationString(CalendarItemViewModel calendarItemViewModel, CalendarSettings settings)
     {
-        if (calendarItemViewModel == null || settings == null) return string.Empty;
-
-        // Single event in a day.
-        if (!calendarItemViewModel.IsAllDayEvent && !calendarItemViewModel.IsMultiDayEvent)
-        {
-            return $"{calendarItemViewModel.Period.Start.ToString("d", settings.CultureInfo)} {settings.GetTimeString(calendarItemViewModel.Period.Duration)}";
-        }
-        else if (calendarItemViewModel.IsMultiDayEvent)
-        {
-            return $"{calendarItemViewModel.Period.Start.ToString("d", settings.CultureInfo)} - {calendarItemViewModel.Period.End.ToString("d", settings.CultureInfo)}";
-        }
-        else
-        {
-            // All day event.
-            return $"{calendarItemViewModel.Period.Start.ToString("d", settings.CultureInfo)} ({Translator.CalendarItemAllDay})";
-        }
+        // TODO
+        return string.Empty;
     }
 
     public static PopupPlacementMode GetDesiredPlacementModeForEventsDetailsPopup(
@@ -98,8 +59,12 @@ public static class CalendarXamlHelpers
     {
         if (calendarItemViewModel == null) return PopupPlacementMode.Auto;
 
+        bool isAllDayOrMultiDay = calendarItemViewModel.CalendarItem.ItemType == CalendarItemType.MultiDay ||
+            calendarItemViewModel.CalendarItem.ItemType == CalendarItemType.AllDay ||
+            calendarItemViewModel.CalendarItem.ItemType == CalendarItemType.MultiDayAllDay;
+
         // All and/or multi day events always go to the top of the screen.
-        if (calendarItemViewModel.IsAllDayEvent || calendarItemViewModel.IsMultiDayEvent) return PopupPlacementMode.Bottom;
+        if (isAllDayOrMultiDay) return PopupPlacementMode.Bottom;
 
         return XamlHelpers.GetPlaccementModeForCalendarType(calendarDisplayType);
     }

Wino.Calendar/Selectors/CustomAreaCalendarItemSelector.cs

@@ -13,7 +13,8 @@ public partial class CustomAreaCalendarItemSelector : DataTemplateSelector
     {
         if (item is CalendarItemViewModel calendarItemViewModel)
         {
-            return calendarItemViewModel.IsMultiDayEvent ? MultiDayTemplate : AllDayTemplate;
+            return calendarItemViewModel.CalendarItem.ItemType == Core.Domain.Enums.CalendarItemType.MultiDay ||
+                calendarItemViewModel.CalendarItem.ItemType == Core.Domain.Enums.CalendarItemType.MultiDayAllDay ? MultiDayTemplate : AllDayTemplate;
         }
 
         return base.SelectTemplateCore(item, container);

Wino.Calendar/Views/AppShell.xaml

@@ -89,6 +89,7 @@
                             HorizontalAlignment="Stretch"
                             VerticalAlignment="Center"
                             BorderBrush="Transparent"
+                            IsTabStop="False"
                             PlaceholderText="Search" />
 
                         <StackPanel

Wino.Calendar/Views/EventDetailsPage.xaml

@@ -256,7 +256,7 @@
                                         <PersonPicture
                                             Width="40"
                                             Height="40"
-                                            DisplayName="{x:Bind Name}" />
+                                            DisplayName="{x:Bind DisplayName}" />
 
                                         <!--  TODO: Organizer  -->
                                         <Grid Grid.Column="1">
@@ -265,7 +265,7 @@
                                                 <RowDefinition Height="Auto" />
                                             </Grid.RowDefinitions>
 
-                                            <TextBlock FontWeight="SemiBold" Text="{x:Bind Name}" />
+                                            <TextBlock FontWeight="SemiBold" Text="{x:Bind DisplayName}" />
                                             <TextBlock
                                                 Grid.Row="1"
                                                 FontSize="13"

Wino.Core.Domain/Collections/CalendarEventCollection.cs

@@ -80,11 +80,11 @@ public class CalendarEventCollection
         // Multi-day events go to both.
         // Anything else goes to regular.
 
-        if (calendarItem.IsAllDayEvent)
+        if (calendarItem.ItemType == Enums.CalendarItemType.AllDay || calendarItem.ItemType == Enums.CalendarItemType.MultiDayAllDay || calendarItem.ItemType == Enums.CalendarItemType.RecurringAllDay)
         {
             return [_internalAllDayEvents];
         }
-        else if (calendarItem.IsMultiDayEvent)
+        else if (calendarItem.ItemType == Enums.CalendarItemType.MultiDay || calendarItem.ItemType == Enums.CalendarItemType.MultiDayAllDay)
         {
             return [_internalRegularEvents, _internalAllDayEvents];
         }

Wino.Core.Domain/Constants.cs

@@ -8,8 +8,6 @@ public static class Constants
     public const string WinoLocalDraftHeader = "X-Wino-Draft-Id";
     public const string LocalDraftStartPrefix = "localDraft_";
 
-    public const string CalendarEventRecurrenceRuleSeperator = "___";
-
     public const string ToastMailUniqueIdKey = nameof(ToastMailUniqueIdKey);
     public const string ToastActionKey = nameof(ToastActionKey);
 

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

@@ -7,12 +7,40 @@ namespace Wino.Core.Domain.Entities.Calendar;
 public class AccountCalendar : IAccountCalendar
 {
     [PrimaryKey]
-    public Guid Id { get; set; }
+    public Guid Id { get; set; } = Guid.NewGuid();
+
+    [NotNull]
+    public string RemoteCalendarId { get; set; } = string.Empty;
+
+    [NotNull]
     public Guid AccountId { get; set; }
-    public string RemoteCalendarId { get; set; }
-    public string SynchronizationDeltaToken { get; set; }
-    public string Name { get; set; }
-    public bool IsPrimary { get; set; }
+
+    [NotNull]
+    public string Name { get; set; } = string.Empty;
+
+    public string? Description { get; set; }
+
+    public string? Location { get; set; }
+
+    public string? TimeZone { get; set; }
+
+    public string? AccessRole { get; set; }
+
+    public bool IsPrimary { get; set; } = false;
+
+    public string? BackgroundColor { get; set; }
+
+    public string? ForegroundColor { get; set; }
+
+    public DateTime CreatedDate { get; set; }
+
+    public DateTime LastModified { get; set; }
+
+    public DateTime? LastSyncTime { get; set; }
+
+    public string? SynchronizationDeltaToken { get; set; }
+
+    public bool IsDeleted { get; set; } = false;
     public bool IsExtended { get; set; } = true;
 
     /// <summary>
@@ -20,5 +48,4 @@ public class AccountCalendar : IAccountCalendar
     /// </summary>
     public string TextColorHex { get; set; }
     public string BackgroundColorHex { get; set; }
-    public string TimeZone { get; set; }
 }

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

@@ -8,12 +8,29 @@ namespace Wino.Core.Domain.Entities.Calendar;
 public class CalendarEventAttendee
 {
     [PrimaryKey]
-    public Guid Id { get; set; }
-    public Guid CalendarItemId { get; set; }
-    public string Name { get; set; }
-    public string Email { get; set; }
-    public AttendeeStatus AttendenceStatus { get; set; }
-    public bool IsOrganizer { get; set; }
-    public bool IsOptionalAttendee { get; set; }
-    public string Comment { get; set; }
+    public Guid Id { get; set; } = Guid.NewGuid();
+
+    [NotNull]
+    public Guid EventId { get; set; }
+
+    [NotNull]
+    public string Email { get; set; } = string.Empty;
+
+    public string? DisplayName { get; set; }
+
+    public AttendeeResponseStatus ResponseStatus { get; set; } = AttendeeResponseStatus.NeedsAction;
+
+    public bool IsOptional { get; set; } = false;
+
+    public bool IsOrganizer { get; set; } = false;
+
+    public bool IsSelf { get; set; } = false;
+
+    public string? Comment { get; set; }
+
+    public int? AdditionalGuests { get; set; }
+
+    public DateTime CreatedDate { get; set; }
+
+    public DateTime LastModified { get; set; }
 }

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

@@ -3,6 +3,7 @@ using System.Diagnostics;
 using Itenso.TimePeriod;
 using SQLite;
 using Wino.Core.Domain.Enums;
+using Wino.Core.Domain.Helpers;
 using Wino.Core.Domain.Interfaces;
 
 namespace Wino.Core.Domain.Entities.Calendar;
@@ -11,169 +12,81 @@ namespace Wino.Core.Domain.Entities.Calendar;
 public class CalendarItem : ICalendarItem
 {
     [PrimaryKey]
-    public Guid Id { get; set; }
-    public string RemoteEventId { get; set; }
-    public string Title { get; set; }
-    public string Description { get; set; }
-    public string Location { get; set; }
+    public Guid Id { get; set; } = Guid.NewGuid();
 
-    public DateTime StartDate { get; set; }
+    [NotNull]
+    public string RemoteEventId { get; set; } = string.Empty;
 
-    public DateTime EndDate
-    {
-        get
-        {
-            return StartDate.AddSeconds(DurationInSeconds);
-        }
-    }
+    [NotNull]
+    public Guid CalendarId { get; set; }
 
-    public TimeSpan StartDateOffset { get; set; }
-    public TimeSpan EndDateOffset { get; set; }
+    [Ignore]
+    public IAccountCalendar AssignedCalendar { get; set; }
+
+    [NotNull]
+    public string Title { get; set; } = string.Empty;
+
+    public string? Description { get; set; }
+
+    public string? Location { get; set; }
+    public string? HtmlLink { get; set; }
+
+    public DateTime StartDateTime { get; set; }
+
+    public DateTime EndDateTime { get; set; }
 
     private ITimePeriod _period;
     public ITimePeriod Period
     {
         get
         {
-            _period ??= new TimeRange(StartDate, EndDate);
+            _period ??= new TimeRange(StartDateTime, EndDateTime);
 
             return _period;
         }
     }
 
-    /// <summary>
-    /// Events that starts at midnight and ends at midnight are considered all-day events.
-    /// </summary>
-    public bool IsAllDayEvent
-    {
-        get
-        {
-            return
-                StartDate.TimeOfDay == TimeSpan.Zero &&
-                EndDate.TimeOfDay == TimeSpan.Zero;
-        }
-    }
+    public bool IsAllDay { get; set; }
+
+    public string? TimeZone { get; set; }
+
+    public string? RecurrenceRules { get; set; }
+
+    public string? Status { get; set; }
+
+    public string? OrganizerDisplayName { get; set; }
+
+    public string? OrganizerEmail { get; set; }
+
+    public DateTime CreatedDate { get; set; }
+
+    public DateTime LastModified { get; set; }
+
+    public bool IsDeleted { get; set; }
+
+    public string? RecurringEventId { get; set; }
+
+    public string? OriginalStartTime { get; set; }
 
     /// <summary>
-    /// Events that are either an exceptional instance of a recurring event or occurrences.
-    /// IsOccurrence is used to display occurrence instances of parent recurring events.
-    /// IsOccurrence == false && IsRecurringChild == true => exceptional single instance.
+    /// The type of calendar item (Timed, AllDay, MultiDay, etc.)
     /// </summary>
-    public bool IsRecurringChild
-    {
-        get
-        {
-            return RecurringCalendarItemId != null;
-        }
-    }
+    public CalendarItemType ItemType { get; set; }
 
     /// <summary>
-    /// Events that are either an exceptional instance of a recurring event or occurrences.
+    /// Automatically determines and sets the ItemType based on event properties
     /// </summary>
-    public bool IsRecurringEvent => IsRecurringChild || IsRecurringParent;
+    public void DetermineItemType()
+    {
+        var hasRecurrence = !string.IsNullOrEmpty(RecurrenceRules);
+        var isCancelled = Status?.ToLowerInvariant() == "cancelled" || IsDeleted;
 
-    /// <summary>
-    /// Events that are the master event definition of recurrence events.
-    /// </summary>
-    public bool IsRecurringParent
-    {
-        get
-        {
-            return !string.IsNullOrEmpty(Recurrence) && RecurringCalendarItemId == null;
-        }
-    }
-
-    /// <summary>
-    /// Events that are not all-day events and last more than one day are considered multi-day events.
-    /// </summary>
-    public bool IsMultiDayEvent
-    {
-        get
-        {
-            return Period.Duration.TotalDays >= 1 && !IsAllDayEvent;
-        }
-    }
-
-    public double DurationInSeconds { get; set; }
-    public string Recurrence { get; set; }
-
-    public string OrganizerDisplayName { get; set; }
-    public string OrganizerEmail { get; set; }
-
-    /// <summary>
-    /// The id of the parent calendar item of the recurring event.
-    /// Exceptional instances are stored as a separate calendar item.
-    /// This makes the calendar item a child of the recurring event.
-    /// </summary>
-    public Guid? RecurringCalendarItemId { get; set; }
-
-    /// <summary>
-    /// Indicates read-only events. Default is false.
-    /// </summary>
-    public bool IsLocked { get; set; }
-
-    /// <summary>
-    /// Hidden events must not be displayed to the user.
-    /// This usually happens when a child instance of recurring parent is cancelled after creation.
-    /// </summary>
-    public bool IsHidden { get; set; }
-
-    // TODO
-    public string CustomEventColorHex { get; set; }
-    public string HtmlLink { get; set; }
-    public CalendarItemStatus Status { get; set; }
-    public CalendarItemVisibility Visibility { get; set; }
-    public DateTimeOffset CreatedAt { get; set; }
-    public DateTimeOffset UpdatedAt { get; set; }
-    public Guid CalendarId { get; set; }
-
-    [Ignore]
-    public IAccountCalendar AssignedCalendar { get; set; }
-
-    /// <summary>
-    /// Whether this item does not really exist in the database or not.
-    /// These are used to display occurrence instances of parent recurring events.
-    /// </summary>
-    [Ignore]
-    public bool IsOccurrence { get; set; }
-
-    /// <summary>
-    /// Id to load information related to this event.
-    /// Occurrences tracked by the parent recurring event if they are not exceptional instances.
-    /// Recurring children here are exceptional instances. They have their own info in the database including Id.
-    /// </summary>
-    public Guid EventTrackingId => IsOccurrence ? RecurringCalendarItemId.Value : Id;
-
-    public CalendarItem CreateRecurrence(DateTime startDate, double durationInSeconds)
-    {
-        // Create a copy with the new start date and duration
-
-        return new CalendarItem
-        {
-            Id = Guid.NewGuid(),
-            Title = Title,
-            Description = Description,
-            Location = Location,
-            StartDate = startDate,
-            DurationInSeconds = durationInSeconds,
-            Recurrence = Recurrence,
-            OrganizerDisplayName = OrganizerDisplayName,
-            OrganizerEmail = OrganizerEmail,
-            RecurringCalendarItemId = Id,
-            AssignedCalendar = AssignedCalendar,
-            CalendarId = CalendarId,
-            CreatedAt = CreatedAt,
-            UpdatedAt = UpdatedAt,
-            Visibility = Visibility,
-            Status = Status,
-            CustomEventColorHex = CustomEventColorHex,
-            HtmlLink = HtmlLink,
-            StartDateOffset = StartDateOffset,
-            EndDateOffset = EndDateOffset,
-            RemoteEventId = RemoteEventId,
-            IsHidden = IsHidden,
-            IsLocked = IsLocked,
-            IsOccurrence = true
-        };
+        ItemType = CalendarItemTypeHelper.DetermineItemType(
+            StartDateTime,
+            EndDateTime,
+            IsAllDay,
+            hasRecurrence,
+            isCancelled,
+            Status);
     }
 }

Wino.Core.Domain/Enums/AttendeeResponseStatus.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Wino.Core.Domain.Enums;
+/// <summary>
+/// Represents the response status of an attendee to a calendar event
+/// </summary>
+public enum AttendeeResponseStatus
+{
+    /// <summary>
+    /// The attendee has not responded to the invitation
+    /// </summary>
+    NeedsAction = 0,
+
+    /// <summary>
+    /// The attendee has accepted the invitation
+    /// </summary>
+    Accepted = 1,
+
+    /// <summary>
+    /// The attendee has declined the invitation
+    /// </summary>
+    Declined = 2,
+
+    /// <summary>
+    /// The attendee has tentatively accepted the invitation
+    /// </summary>
+    Tentative = 3
+}

Wino.Core.Domain/Enums/CalendarItemType.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Wino.Core.Domain.Enums;
+public enum CalendarItemType
+{
+    /// <summary>
+    /// A standard timed event with specific start and end times on the same day
+    /// </summary>
+    Timed = 0,
+
+    /// <summary>
+    /// An all-day event that spans exactly one day
+    /// </summary>
+    AllDay = 1,
+
+    /// <summary>
+    /// A multi-day event that spans more than one day but has specific times
+    /// </summary>
+    MultiDay = 2,
+
+    /// <summary>
+    /// A multi-day all-day event (e.g., vacation, conference spanning multiple days)
+    /// </summary>
+    MultiDayAllDay = 3,
+
+    /// <summary>
+    /// A recurring event with a defined pattern (daily, weekly, monthly, yearly)
+    /// </summary>
+    Recurring = 4,
+
+    /// <summary>
+    /// A recurring all-day event (e.g., annual holiday, weekly all-day event)
+    /// </summary>
+    RecurringAllDay = 5,
+
+    /// <summary>
+    /// A single instance of a recurring event that has been modified
+    /// </summary>
+    RecurringException = 6,
+
+    /// <summary>
+    /// An event that extends beyond midnight but is not multi-day (e.g., 11 PM to 2 AM)
+    /// </summary>
+    CrossMidnight = 7,
+}

Wino.Core.Domain/Helpers/CalendarItemTypeHelper.cs

@@ -0,0 +1,143 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Wino.Core.Domain.Enums;
+
+namespace Wino.Core.Domain.Helpers;
+/// <summary>
+/// Helper class for CalendarItemType operations
+/// </summary>
+public static class CalendarItemTypeHelper
+{
+    /// <summary>
+    /// Determines the calendar item type based on event properties
+    /// </summary>
+    /// <param name="startDateTime">Event start date/time</param>
+    /// <param name="endDateTime">Event end date/time</param>
+    /// <param name="isAllDay">Whether the event is marked as all-day</param>
+    /// <param name="isRecurring">Whether the event has recurrence rules</param>
+    /// <param name="isCancelled">Whether the event is cancelled</param>
+    /// <param name="status">Event status</param>
+    /// <returns>The appropriate CalendarItemType</returns>
+    public static CalendarItemType DetermineItemType(
+        DateTime startDateTime,
+        DateTime endDateTime,
+        bool isAllDay,
+        bool isRecurring = false,
+        bool isCancelled = false,
+        string? status = null)
+    {
+        // Handle recurring events
+        if (isRecurring)
+        {
+            return isAllDay ? CalendarItemType.RecurringAllDay : CalendarItemType.Recurring;
+        }
+
+        // Handle all-day events
+        if (isAllDay)
+        {
+            var daySpan = (endDateTime.Date - startDateTime.Date).Days;
+            return daySpan > 1 ? CalendarItemType.MultiDayAllDay : CalendarItemType.AllDay;
+        }
+
+        // Handle timed events
+        var duration = endDateTime - startDateTime;
+
+
+
+        // Multi-day timed events
+        if (duration.TotalDays >= 1)
+        {
+            return CalendarItemType.MultiDay;
+        }
+
+        // Cross midnight events (same calendar day but extends past midnight)
+        if (startDateTime.Date != endDateTime.Date && duration.TotalHours <= 24)
+        {
+            return CalendarItemType.CrossMidnight;
+        }
+
+        // Standard timed events
+        return CalendarItemType.Timed;
+    }
+
+    /// <summary>
+    /// Gets a human-readable description of the calendar item type
+    /// </summary>
+    /// <param name="itemType">The calendar item type</param>
+    /// <returns>Description string</returns>
+    public static string GetDescription(CalendarItemType itemType)
+    {
+        return itemType switch
+        {
+            CalendarItemType.Timed => "Timed Event",
+            CalendarItemType.AllDay => "All-Day Event",
+            CalendarItemType.MultiDay => "Multi-Day Event",
+            CalendarItemType.MultiDayAllDay => "Multi-Day All-Day Event",
+            CalendarItemType.Recurring => "Recurring Event",
+            CalendarItemType.RecurringAllDay => "Recurring All-Day Event",
+            CalendarItemType.RecurringException => "Modified Recurring Event",
+            CalendarItemType.CrossMidnight => "Cross-Midnight Event",
+            _ => "Unknown Event Type"
+        };
+    }
+
+    /// <summary>
+    /// Checks if the event type represents an all-day event
+    /// </summary>
+    /// <param name="itemType">The calendar item type</param>
+    /// <returns>True if it's an all-day event type</returns>
+    public static bool IsAllDayType(CalendarItemType itemType)
+    {
+        return itemType == CalendarItemType.AllDay ||
+               itemType == CalendarItemType.MultiDayAllDay ||
+               itemType == CalendarItemType.RecurringAllDay;
+    }
+
+    /// <summary>
+    /// Checks if the event type represents a recurring event
+    /// </summary>
+    /// <param name="itemType">The calendar item type</param>
+    /// <returns>True if it's a recurring event type</returns>
+    public static bool IsRecurringType(CalendarItemType itemType)
+    {
+        return itemType == CalendarItemType.Recurring ||
+               itemType == CalendarItemType.RecurringAllDay ||
+               itemType == CalendarItemType.RecurringException;
+    }
+
+    /// <summary>
+    /// Checks if the event type represents a multi-day event
+    /// </summary>
+    /// <param name="itemType">The calendar item type</param>
+    /// <returns>True if it's a multi-day event type</returns>
+    public static bool IsMultiDayType(CalendarItemType itemType)
+    {
+        return itemType == CalendarItemType.MultiDay ||
+               itemType == CalendarItemType.MultiDayAllDay;
+    }
+
+    /// <summary>
+    /// Gets the priority level for sorting events (lower number = higher priority)
+    /// </summary>
+    /// <param name="itemType">The calendar item type</param>
+    /// <returns>Priority number for sorting</returns>
+    public static int GetSortPriority(CalendarItemType itemType)
+    {
+        return itemType switch
+        {
+
+            CalendarItemType.AllDay => 2,
+            CalendarItemType.MultiDayAllDay => 3,
+            CalendarItemType.Timed => 4,
+            CalendarItemType.CrossMidnight => 5,
+            CalendarItemType.MultiDay => 6,
+            CalendarItemType.Recurring => 7,
+            CalendarItemType.RecurringAllDay => 8,
+            CalendarItemType.RecurringException => 9,
+            _ => 99
+        };
+    }
+}

Wino.Core.Domain/Interfaces/ICalendarItem.cs

@@ -1,5 +1,6 @@
 using System;
 using Itenso.TimePeriod;
+using Wino.Core.Domain.Enums;
 
 namespace Wino.Core.Domain.Interfaces;
 
@@ -8,15 +9,8 @@ public interface ICalendarItem
     string Title { get; }
     Guid Id { get; }
     IAccountCalendar AssignedCalendar { get; }
-    DateTime StartDate { get; set; }
-    DateTime EndDate { get; }
-    double DurationInSeconds { get; set; }
+    DateTime StartDateTime { get; set; }
+    DateTime EndDateTime { get; }
     ITimePeriod Period { get; }
-
-    bool IsAllDayEvent { get; }
-    bool IsMultiDayEvent { get; }
-
-    bool IsRecurringChild { get; }
-    bool IsRecurringParent { get; }
-    bool IsRecurringEvent { get; }
+    CalendarItemType ItemType { get; }
 }

Wino.Core.Domain/Interfaces/ICalendarItemViewModel.cs

@@ -1,9 +1,13 @@
-namespace Wino.Core.Domain.Interfaces;
+using System;
+
+namespace Wino.Core.Domain.Interfaces;
 
 /// <summary>
 /// Temporarily to enforce CalendarItemViewModel. Used in CalendarEventCollection.
 /// </summary>
-public interface ICalendarItemViewModel
+public interface ICalendarItemViewModel : ICalendarItem
 {
     bool IsSelected { get; set; }
+    DateTime LocalStartDateTime { get; }
+    DateTime LocalEndDateTime { get; }
 }

Wino.Core.Domain/Interfaces/ICalendarServiceEx.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Wino.Core.Domain.Entities.Calendar;
+using Wino.Core.Domain.Enums;
+
+namespace Wino.Core.Domain.Interfaces;
+public interface ICalendarServiceEx
+{
+    Task<int> ClearAllCalendarEventAttendeesAsync();
+    Task<int> ClearAllCalendarsAsync();
+    Task<int> ClearAllDataAsync();
+    Task<int> ClearAllEventsAsync();
+    Task<int> DeleteCalendarAsync(string remoteCalendarId);
+    Task<int> DeleteCalendarEventAttendeesForEventAsync(Guid eventId);
+    Task<int> DeleteEventAsync(string remoteEventId);
+    Task<List<CalendarEventAttendee>> GetAllCalendarEventAttendeesAsync();
+    Task<List<AccountCalendar>> GetAllCalendarsAsync();
+    Task<List<CalendarItem>> GetAllDayEventsAsync();
+    Task<List<CalendarItem>> GetAllEventsAsync();
+    Task<List<CalendarItem>> GetAllEventsIncludingDeletedAsync();
+    Task<List<CalendarItem>> GetAllRecurringEventsByTypeAsync();
+    Task<AccountCalendar> GetCalendarByRemoteIdAsync(string remoteCalendarId);
+    Task<Dictionary<AttendeeResponseStatus, int>> GetCalendarEventAttendeeResponseCountsAsync(Guid eventId);
+    Task<List<CalendarEventAttendee>> GetCalendarEventAttendeesForEventAsync(Guid eventId);
+    Task<List<CalendarEventAttendee>> GetCalendarEventAttendeesForEventByRemoteIdAsync(string remoteEventId);
+    Task<string> GetCalendarSyncTokenAsync(string calendarId);
+    Task<CalendarItem> GetEventByRemoteIdAsync(string remoteEventId);
+    Task<List<CalendarItem>> GetEventsByItemTypeAsync(CalendarItemType itemType);
+    Task<List<CalendarItem>> GetEventsByItemTypesAsync(params CalendarItemType[] itemTypes);
+    Task<List<CalendarItem>> GetEventsByremoteCalendarIdAsync(string remoteCalendarId);
+    Task<List<CalendarItem>> GetEventsForCalendarAsync(Guid calendarId);
+    Task<List<CalendarItem>> GetEventsInDateRangeAsync(DateTime startDate, DateTime endDate);
+    Task<List<CalendarItem>> GetEventsSinceLastSyncAsync(DateTime? lastSyncTime);
+    Task<Dictionary<CalendarItemType, int>> GetEventStatsByItemTypeAsync();
+    Task<List<CalendarItem>> GetExpandedEventsInDateRangeAsync(DateTime startDate, DateTime endDate);
+    Task<List<CalendarItem>> GetExpandedEventsInDateRangeWithExceptionsAsync(DateTime startDate, DateTime endDate, AccountCalendar calendar);
+    Task<DateTime?> GetLastSyncTimeAsync(string calendarId);
+    Task<List<CalendarItem>> GetMultiDayEventsAsync();
+    Task<List<CalendarItem>> GetRecurringEventsAsync();
+    Task<int> HardDeleteEventAsync(string remoteEventId);
+    Task<int> InsertCalendarAsync(AccountCalendar calendar);
+    Task<int> InsertCalendarEventAttendeeAsync(CalendarEventAttendee calendareventattendee);
+    Task<int> InsertEventAsync(CalendarItem calendarItem);
+    Task<int> MarkEventAsDeletedAsync(string remoteEventId, string remoteCalendarId);
+    Task<int> SyncAttendeesForEventAsync(Guid eventId, List<CalendarEventAttendee> attendees);
+    Task<int> SyncCalendarEventAttendeesForEventAsync(Guid eventId, List<CalendarEventAttendee> calendareventattendees);
+    Task<int> UpdateAllEventItemTypesAsync();
+    Task<int> UpdateCalendarAsync(AccountCalendar calendar);
+    Task<int> UpdateCalendarEventAttendeeAsync(CalendarEventAttendee calendareventattendee);
+    Task<int> UpdateCalendarSyncTokenAsync(string calendarId, string syncToken);
+    Task<int> UpdateEventAsync(CalendarItem calendarItem);
+    Task<int> UpsertCalendarAsync(AccountCalendar calendar);
+    Task<int> UpsertEventAsync(CalendarItem calendarItem);
+}

Wino.Core/Extensions/GoogleIntegratorExtensions.cs

@@ -5,7 +5,6 @@ using System.Web;
 using Google.Apis.Calendar.v3.Data;
 using Google.Apis.Gmail.v1.Data;
 using MimeKit;
-using Wino.Core.Domain;
 using Wino.Core.Domain.Entities.Calendar;
 using Wino.Core.Domain.Entities.Mail;
 using Wino.Core.Domain.Enums;
@@ -179,6 +178,11 @@ public static class GoogleIntegratorExtensions
             Id = Guid.NewGuid(),
             TimeZone = calendarListEntry.TimeZone,
             IsPrimary = calendarListEntry.Primary.GetValueOrDefault(),
+            Description = calendarListEntry.Description,
+            AccessRole = calendarListEntry.AccessRole,
+            CreatedDate = DateTime.UtcNow,
+            LastSyncTime = DateTime.UtcNow,
+            Location = calendarListEntry.Location,
         };
 
         // Bg color must present. Generate one if doesnt exists.
@@ -190,42 +194,121 @@ public static class GoogleIntegratorExtensions
         return calendar;
     }
 
-    public static DateTimeOffset? GetEventDateTimeOffset(EventDateTime calendarEvent)
+    public static CalendarItem MapGoogleEventToCalendarEvent(this Event googleEvent, AccountCalendar calendar)
     {
-        if (calendarEvent != null)
+        var calendarEvent = new CalendarItem
         {
-            if (calendarEvent.DateTimeDateTimeOffset != null)
+            RemoteEventId = googleEvent.Id,
+            CalendarId = calendar.Id, // Use internal Guid
+            Title = googleEvent.Summary ?? string.Empty,
+            Description = googleEvent.Description,
+            Location = googleEvent.Location,
+            Status = googleEvent.Status,
+            RecurringEventId = googleEvent.RecurringEventId
+        };
+
+        // Handle start and end times
+        if (googleEvent.Start != null)
         {
-                return calendarEvent.DateTimeDateTimeOffset.Value;
+            if (googleEvent.Start.Date != null)
+            {
+                calendarEvent.IsAllDay = true;
+                calendarEvent.StartDateTime = DateTime.Parse(googleEvent.Start.Date);
             }
-            else if (calendarEvent.Date != null)
+            else if (googleEvent.Start.DateTimeDateTimeOffset.HasValue)
             {
-                if (DateTime.TryParse(calendarEvent.Date, out DateTime eventDateTime))
-                {
-                    // Date-only events are treated as UTC midnight
-                    return new DateTimeOffset(eventDateTime, TimeSpan.Zero);
-                }
-                else
-                {
-                    throw new Exception("Invalid date format in Google Calendar event date.");
-                }
+                calendarEvent.IsAllDay = false;
+                calendarEvent.StartDateTime = googleEvent.Start.DateTimeDateTimeOffset.Value.DateTime;
+                calendarEvent.TimeZone = googleEvent.Start.TimeZone;
             }
         }
 
-        return null;
+        if (googleEvent.End != null)
+        {
+            if (googleEvent.End.Date != null)
+            {
+                calendarEvent.EndDateTime = DateTime.Parse(googleEvent.End.Date);
+            }
+            else if (googleEvent.End.DateTimeDateTimeOffset.HasValue)
+            {
+                calendarEvent.EndDateTime = googleEvent.End.DateTimeDateTimeOffset.Value.DateTime;
+            }
+        }
+
+        // Handle recurrence rules
+        if (googleEvent.Recurrence != null && googleEvent.Recurrence.Count > 0)
+        {
+            calendarEvent.RecurrenceRules = string.Join(";", googleEvent.Recurrence);
+        }
+
+        // Handle organizer
+        if (googleEvent.Organizer != null)
+        {
+            calendarEvent.OrganizerDisplayName = googleEvent.Organizer.DisplayName;
+            calendarEvent.OrganizerEmail = googleEvent.Organizer.Email;
+        }
+
+        // Handle timestamps
+        if (googleEvent.CreatedDateTimeOffset.HasValue)
+        {
+            calendarEvent.CreatedDate = googleEvent.CreatedDateTimeOffset.Value.DateTime;
+        }
+
+        if (googleEvent.UpdatedDateTimeOffset.HasValue)
+        {
+            calendarEvent.LastModified = googleEvent.UpdatedDateTimeOffset.Value.DateTime;
+        }
+
+        // Handle original start time for recurring event instances
+        if (googleEvent.OriginalStartTime != null)
+        {
+            if (googleEvent.OriginalStartTime.Date != null)
+            {
+                calendarEvent.OriginalStartTime = googleEvent.OriginalStartTime.Date;
+            }
+            else if (googleEvent.OriginalStartTime.DateTimeDateTimeOffset.HasValue)
+            {
+                calendarEvent.OriginalStartTime = googleEvent.OriginalStartTime.DateTimeDateTimeOffset.Value.ToString("O");
+            }
+        }
+
+        // Automatically determine the calendar item type based on event properties
+        calendarEvent.DetermineItemType();
+
+        return calendarEvent;
     }
 
     /// <summary>
-    /// RRULE, EXRULE, RDATE and EXDATE lines for a recurring event, as specified in RFC5545.
+    /// Converts a Google Calendar API response status string to AttendeeResponseStatus enum
     /// </summary>
-    /// <returns>___ separated lines.</returns>
-    public static string GetRecurrenceString(this Event calendarEvent)
+    /// <param name="googleStatus">The status string from Google Calendar API</param>
+    /// <returns>Corresponding AttendeeResponseStatus enum value</returns>
+    public static AttendeeResponseStatus FromGoogleStatus(string? googleStatus)
     {
-        if (calendarEvent == null || calendarEvent.Recurrence == null || !calendarEvent.Recurrence.Any())
+        return googleStatus?.ToLowerInvariant() switch
         {
-            return null;
+            "accepted" => AttendeeResponseStatus.Accepted,
+            "declined" => AttendeeResponseStatus.Declined,
+            "tentative" => AttendeeResponseStatus.Tentative,
+            "needsaction" => AttendeeResponseStatus.NeedsAction,
+            _ => AttendeeResponseStatus.NeedsAction
+        };
     }
 
-        return string.Join(Constants.CalendarEventRecurrenceRuleSeperator, calendarEvent.Recurrence);
+    /// <summary>
+    /// Converts an AttendeeResponseStatus enum to Google Calendar API response status string
+    /// </summary>
+    /// <param name="status">The AttendeeResponseStatus enum value</param>
+    /// <returns>Corresponding Google Calendar API status string</returns>
+    public static string ToGoogleStatus(AttendeeResponseStatus status)
+    {
+        return status switch
+        {
+            AttendeeResponseStatus.Accepted => "accepted",
+            AttendeeResponseStatus.Declined => "declined",
+            AttendeeResponseStatus.Tentative => "tentative",
+            AttendeeResponseStatus.NeedsAction => "needsAction",
+            _ => "needsAction"
+        };
     }
 }

Wino.Core/Extensions/OutlookIntegratorExtensions.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
 using Microsoft.Graph.Models;
 using MimeKit;
 using Wino.Core.Domain.Entities.Calendar;
@@ -127,125 +126,26 @@ public static class OutlookIntegratorExtensions
         return calendar;
     }
 
-    private static string GetRfc5545DayOfWeek(DayOfWeekObject dayOfWeek)
+
+
+    /// <summary>
+    /// Converts Outlook response status to our enum
+    /// </summary>
+    /// <param name="outlookResponse">Outlook response type</param>
+    /// <returns>AttendeeResponseStatus enum value</returns>
+    public static AttendeeResponseStatus ConvertOutlookResponseStatus(this Microsoft.Graph.Models.ResponseType? outlookResponse)
     {
-        return dayOfWeek switch
+        return outlookResponse switch
         {
-            DayOfWeekObject.Monday => "MO",
-            DayOfWeekObject.Tuesday => "TU",
-            DayOfWeekObject.Wednesday => "WE",
-            DayOfWeekObject.Thursday => "TH",
-            DayOfWeekObject.Friday => "FR",
-            DayOfWeekObject.Saturday => "SA",
-            DayOfWeekObject.Sunday => "SU",
-            _ => throw new ArgumentOutOfRangeException(nameof(dayOfWeek), dayOfWeek, null)
+            Microsoft.Graph.Models.ResponseType.Accepted => AttendeeResponseStatus.Accepted,
+            Microsoft.Graph.Models.ResponseType.Declined => AttendeeResponseStatus.Declined,
+            Microsoft.Graph.Models.ResponseType.TentativelyAccepted => AttendeeResponseStatus.Tentative,
+            Microsoft.Graph.Models.ResponseType.None => AttendeeResponseStatus.NeedsAction,
+            Microsoft.Graph.Models.ResponseType.NotResponded => AttendeeResponseStatus.NeedsAction,
+            _ => AttendeeResponseStatus.NeedsAction
         };
     }
 
-    public static string ToRfc5545RecurrenceString(this PatternedRecurrence recurrence)
-    {
-        if (recurrence == null || recurrence.Pattern == null)
-            throw new ArgumentNullException(nameof(recurrence), "PatternedRecurrence or its Pattern cannot be null.");
-
-        var ruleBuilder = new StringBuilder("RRULE:");
-        var pattern = recurrence.Pattern;
-
-        // Frequency
-        switch (pattern.Type)
-        {
-            case RecurrencePatternType.Daily:
-                ruleBuilder.Append("FREQ=DAILY;");
-                break;
-            case RecurrencePatternType.Weekly:
-                ruleBuilder.Append("FREQ=WEEKLY;");
-                break;
-            case RecurrencePatternType.AbsoluteMonthly:
-                ruleBuilder.Append("FREQ=MONTHLY;");
-                break;
-            case RecurrencePatternType.AbsoluteYearly:
-                ruleBuilder.Append("FREQ=YEARLY;");
-                break;
-            case RecurrencePatternType.RelativeMonthly:
-                ruleBuilder.Append("FREQ=MONTHLY;");
-                break;
-            case RecurrencePatternType.RelativeYearly:
-                ruleBuilder.Append("FREQ=YEARLY;");
-                break;
-            default:
-                throw new NotSupportedException($"Unsupported recurrence pattern type: {pattern.Type}");
-        }
-
-        // Interval
-        if (pattern.Interval > 0)
-            ruleBuilder.Append($"INTERVAL={pattern.Interval};");
-
-        // Days of Week
-        if (pattern.DaysOfWeek?.Any() == true)
-        {
-            var days = string.Join(",", pattern.DaysOfWeek.Select(day => day.ToString().ToUpperInvariant().Substring(0, 2)));
-            ruleBuilder.Append($"BYDAY={days};");
-        }
-
-        // Day of Month (BYMONTHDAY)
-        if (pattern.Type == RecurrencePatternType.AbsoluteMonthly || pattern.Type == RecurrencePatternType.AbsoluteYearly)
-        {
-            if (pattern.DayOfMonth <= 0)
-                throw new ArgumentException("DayOfMonth must be greater than 0 for absoluteMonthly or absoluteYearly patterns.");
-
-            ruleBuilder.Append($"BYMONTHDAY={pattern.DayOfMonth};");
-        }
-
-        // Month (BYMONTH)
-        if (pattern.Type == RecurrencePatternType.AbsoluteYearly || pattern.Type == RecurrencePatternType.RelativeYearly)
-        {
-            if (pattern.Month <= 0)
-                throw new ArgumentException("Month must be greater than 0 for absoluteYearly or relativeYearly patterns.");
-
-            ruleBuilder.Append($"BYMONTH={pattern.Month};");
-        }
-
-        // Count or Until
-        if (recurrence.Range != null)
-        {
-            if (recurrence.Range.Type == RecurrenceRangeType.EndDate && recurrence.Range.EndDate != null)
-            {
-                ruleBuilder.Append($"UNTIL={recurrence.Range.EndDate.Value:yyyyMMddTHHmmssZ};");
-            }
-            else if (recurrence.Range.Type == RecurrenceRangeType.Numbered && recurrence.Range.NumberOfOccurrences.HasValue)
-            {
-                ruleBuilder.Append($"COUNT={recurrence.Range.NumberOfOccurrences.Value};");
-            }
-        }
-
-        // Remove trailing semicolon
-        return ruleBuilder.ToString().TrimEnd(';');
-    }
-
-    public static DateTimeOffset GetDateTimeOffsetFromDateTimeTimeZone(DateTimeTimeZone dateTimeTimeZone)
-    {
-        if (dateTimeTimeZone == null || string.IsNullOrEmpty(dateTimeTimeZone.DateTime) || string.IsNullOrEmpty(dateTimeTimeZone.TimeZone))
-        {
-            throw new ArgumentException("DateTimeTimeZone is null or empty.");
-        }
-
-        try
-        {
-            // Parse the DateTime string
-            if (DateTime.TryParse(dateTimeTimeZone.DateTime, out DateTime parsedDateTime))
-            {
-                // Get TimeZoneInfo to get the offset
-                TimeZoneInfo timeZoneInfo = TimeZoneInfo.FindSystemTimeZoneById(dateTimeTimeZone.TimeZone);
-                TimeSpan offset = timeZoneInfo.GetUtcOffset(parsedDateTime);
-                return new DateTimeOffset(parsedDateTime, offset);
-            }
-            else
-                throw new ArgumentException("DateTime string is not in a valid format.");
-        }
-        catch (Exception)
-        {
-            throw;
-        }
-    }
 
     private static AttendeeStatus GetAttendeeStatus(ResponseType? responseType)
     {
@@ -261,24 +161,6 @@ public static class OutlookIntegratorExtensions
         };
     }
 
-    public static CalendarEventAttendee CreateAttendee(this Attendee attendee, Guid calendarItemId)
-    {
-        bool isOrganizer = attendee?.Status?.Response == ResponseType.Organizer;
-
-        var eventAttendee = new CalendarEventAttendee()
-        {
-            CalendarItemId = calendarItemId,
-            Id = Guid.NewGuid(),
-            Email = attendee.EmailAddress?.Address,
-            Name = attendee.EmailAddress?.Name,
-            AttendenceStatus = GetAttendeeStatus(attendee.Status.Response),
-            IsOrganizer = isOrganizer,
-            IsOptionalAttendee = attendee.Type == AttendeeType.Optional,
-        };
-
-        return eventAttendee;
-    }
-
     #region Mime to Outlook Message Helpers
 
     private static IEnumerable<Recipient> GetRecipients(this InternetAddressList internetAddresses)

Wino.Core/Integration/Processors/DefaultChangeProcessor.cs

@@ -21,7 +21,7 @@ namespace Wino.Core.Integration.Processors;
 /// <see cref="IGmailChangeProcessor"/>,  <see cref="IOutlookChangeProcessor"/> and  <see cref="IImapChangeProcessor"/>
 /// None of the synchronizers can directly change anything in the database.
 /// </summary>
-public interface IDefaultChangeProcessor
+public interface IDefaultChangeProcessor : ICalendarServiceEx
 {
     Task UpdateAccountAsync(MailAccount account);
     // Task<string> UpdateAccountDeltaSynchronizationIdentifierAsync(Guid accountId, string deltaSynchronizationIdentifier);
@@ -113,13 +113,14 @@ public class DefaultChangeProcessor(IDatabaseService databaseService,
                               IMailService mailService,
                               ICalendarService calendarService,
                               IAccountService accountService,
-                              IMimeFileService mimeFileService) : BaseDatabaseService(databaseService), IDefaultChangeProcessor
+                              ICalendarServiceEx calendarServiceEx,
+                              IMimeFileService mimeFileService) : BaseDatabaseService(databaseService), IDefaultChangeProcessor, ICalendarServiceEx
 {
     protected IMailService MailService = mailService;
     protected ICalendarService CalendarService = calendarService;
     protected IFolderService FolderService = folderService;
     protected IAccountService AccountService = accountService;
-
+    private readonly ICalendarServiceEx _calendarServiceEx = calendarServiceEx;
     private readonly IMimeFileService _mimeFileService = mimeFileService;
 
     public Task<string> UpdateAccountDeltaSynchronizationIdentifierAsync(Guid accountId, string synchronizationDeltaIdentifier)
@@ -208,4 +209,234 @@ public class DefaultChangeProcessor(IDatabaseService databaseService,
 
     public Task<bool> IsMailExistsInFolderAsync(string messageId, Guid folderId)
             => MailService.IsMailExistsAsync(messageId, folderId);
+
+    // TODO: Normalize this shit. Not everything needs to be exposed for processor.
+    #region ICalendarServiceEx
+
+    public Task<int> ClearAllCalendarEventAttendeesAsync()
+    {
+        return _calendarServiceEx.ClearAllCalendarEventAttendeesAsync();
+    }
+
+    public Task<int> ClearAllCalendarsAsync()
+    {
+        return _calendarServiceEx.ClearAllCalendarsAsync();
+    }
+
+    public Task<int> ClearAllDataAsync()
+    {
+        return _calendarServiceEx.ClearAllDataAsync();
+    }
+
+    public Task<int> ClearAllEventsAsync()
+    {
+        return _calendarServiceEx.ClearAllEventsAsync();
+    }
+
+    public Task<int> DeleteCalendarAsync(string remoteCalendarId)
+    {
+        return _calendarServiceEx.DeleteCalendarAsync(remoteCalendarId);
+    }
+
+    public Task<int> DeleteCalendarEventAttendeesForEventAsync(Guid eventId)
+    {
+        return _calendarServiceEx.DeleteCalendarEventAttendeesForEventAsync(eventId);
+    }
+
+    public Task<int> DeleteEventAsync(string remoteEventId)
+    {
+        return _calendarServiceEx.DeleteEventAsync(remoteEventId);
+    }
+
+    public Task<List<CalendarEventAttendee>> GetAllCalendarEventAttendeesAsync()
+    {
+        return _calendarServiceEx.GetAllCalendarEventAttendeesAsync();
+    }
+
+    public Task<List<AccountCalendar>> GetAllCalendarsAsync()
+    {
+        return _calendarServiceEx.GetAllCalendarsAsync();
+    }
+
+    public Task<List<CalendarItem>> GetAllDayEventsAsync()
+    {
+        return _calendarServiceEx.GetAllDayEventsAsync();
+    }
+
+    public Task<List<CalendarItem>> GetAllEventsAsync()
+    {
+        return _calendarServiceEx.GetAllEventsAsync();
+    }
+
+    public Task<List<CalendarItem>> GetAllEventsIncludingDeletedAsync()
+    {
+        return _calendarServiceEx.GetAllEventsIncludingDeletedAsync();
+    }
+
+    public Task<List<CalendarItem>> GetAllRecurringEventsByTypeAsync()
+    {
+        return _calendarServiceEx.GetAllRecurringEventsByTypeAsync();
+    }
+
+    public Task<AccountCalendar> GetCalendarByRemoteIdAsync(string remoteCalendarId)
+    {
+        return _calendarServiceEx.GetCalendarByRemoteIdAsync(remoteCalendarId);
+    }
+
+    public Task<Dictionary<AttendeeResponseStatus, int>> GetCalendarEventAttendeeResponseCountsAsync(Guid eventId)
+    {
+        return _calendarServiceEx.GetCalendarEventAttendeeResponseCountsAsync(eventId);
+    }
+
+    public Task<List<CalendarEventAttendee>> GetCalendarEventAttendeesForEventAsync(Guid eventId)
+    {
+        return _calendarServiceEx.GetCalendarEventAttendeesForEventAsync(eventId);
+    }
+
+    public Task<List<CalendarEventAttendee>> GetCalendarEventAttendeesForEventByRemoteIdAsync(string remoteEventId)
+    {
+        return _calendarServiceEx.GetCalendarEventAttendeesForEventByRemoteIdAsync(remoteEventId);
+    }
+
+    public Task<string> GetCalendarSyncTokenAsync(string calendarId)
+    {
+        return _calendarServiceEx.GetCalendarSyncTokenAsync(calendarId);
+    }
+
+    public Task<CalendarItem> GetEventByRemoteIdAsync(string remoteEventId)
+    {
+        return _calendarServiceEx.GetEventByRemoteIdAsync(remoteEventId);
+    }
+
+    public Task<List<CalendarItem>> GetEventsByItemTypeAsync(CalendarItemType itemType)
+    {
+        return _calendarServiceEx.GetEventsByItemTypeAsync(itemType);
+    }
+
+    public Task<List<CalendarItem>> GetEventsByItemTypesAsync(params CalendarItemType[] itemTypes)
+    {
+        return _calendarServiceEx.GetEventsByItemTypesAsync(itemTypes);
+    }
+
+    public Task<List<CalendarItem>> GetEventsByremoteCalendarIdAsync(string remoteCalendarId)
+    {
+        return _calendarServiceEx.GetEventsByremoteCalendarIdAsync(remoteCalendarId);
+    }
+
+    public Task<List<CalendarItem>> GetEventsForCalendarAsync(Guid calendarId)
+    {
+        return _calendarServiceEx.GetEventsForCalendarAsync(calendarId);
+    }
+
+    public Task<List<CalendarItem>> GetEventsInDateRangeAsync(DateTime startDate, DateTime endDate)
+    {
+        return _calendarServiceEx.GetEventsInDateRangeAsync(startDate, endDate);
+    }
+
+    public Task<List<CalendarItem>> GetEventsSinceLastSyncAsync(DateTime? lastSyncTime)
+    {
+        return _calendarServiceEx.GetEventsSinceLastSyncAsync(lastSyncTime);
+    }
+
+    public Task<Dictionary<CalendarItemType, int>> GetEventStatsByItemTypeAsync()
+    {
+        return _calendarServiceEx.GetEventStatsByItemTypeAsync();
+    }
+
+    public Task<List<CalendarItem>> GetExpandedEventsInDateRangeAsync(DateTime startDate, DateTime endDate)
+    {
+        return _calendarServiceEx.GetExpandedEventsInDateRangeAsync(startDate, endDate);
+    }
+
+    public Task<List<CalendarItem>> GetExpandedEventsInDateRangeWithExceptionsAsync(DateTime startDate, DateTime endDate, AccountCalendar calendar)
+    {
+        return _calendarServiceEx.GetExpandedEventsInDateRangeWithExceptionsAsync(startDate, endDate, calendar);
+    }
+
+    public Task<DateTime?> GetLastSyncTimeAsync(string calendarId)
+    {
+        return _calendarServiceEx.GetLastSyncTimeAsync(calendarId);
+    }
+
+    public Task<List<CalendarItem>> GetMultiDayEventsAsync()
+    {
+        return _calendarServiceEx.GetMultiDayEventsAsync();
+    }
+
+    public Task<List<CalendarItem>> GetRecurringEventsAsync()
+    {
+        return _calendarServiceEx.GetRecurringEventsAsync();
+    }
+
+    public Task<int> HardDeleteEventAsync(string remoteEventId)
+    {
+        return _calendarServiceEx.HardDeleteEventAsync(remoteEventId);
+    }
+
+    public Task<int> InsertCalendarAsync(AccountCalendar calendar)
+    {
+        return _calendarServiceEx.InsertCalendarAsync(calendar);
+    }
+
+    public Task<int> InsertCalendarEventAttendeeAsync(CalendarEventAttendee calendareventattendee)
+    {
+        return _calendarServiceEx.InsertCalendarEventAttendeeAsync(calendareventattendee);
+    }
+
+    public Task<int> InsertEventAsync(CalendarItem calendarItem)
+    {
+        return _calendarServiceEx.InsertEventAsync(calendarItem);
+    }
+
+    public Task<int> MarkEventAsDeletedAsync(string remoteEventId, string remoteCalendarId)
+    {
+        return _calendarServiceEx.MarkEventAsDeletedAsync(remoteEventId, remoteCalendarId);
+    }
+
+    public Task<int> SyncCalendarEventAttendeesForEventAsync(Guid eventId, List<CalendarEventAttendee> calendareventattendees)
+    {
+        return _calendarServiceEx.SyncCalendarEventAttendeesForEventAsync(eventId, calendareventattendees);
+    }
+
+    public Task<int> UpdateAllEventItemTypesAsync()
+    {
+        return _calendarServiceEx.UpdateAllEventItemTypesAsync();
+    }
+
+    public Task<int> UpdateCalendarAsync(AccountCalendar calendar)
+    {
+        return _calendarServiceEx.UpdateCalendarAsync(calendar);
+    }
+
+    public Task<int> UpdateCalendarEventAttendeeAsync(CalendarEventAttendee calendareventattendee)
+    {
+        return _calendarServiceEx.UpdateCalendarEventAttendeeAsync(calendareventattendee);
+    }
+
+    public Task<int> UpdateCalendarSyncTokenAsync(string calendarId, string syncToken)
+    {
+        return _calendarServiceEx.UpdateCalendarSyncTokenAsync(calendarId, syncToken);
+    }
+
+    public Task<int> UpdateEventAsync(CalendarItem calendarItem)
+    {
+        return _calendarServiceEx.UpdateEventAsync(calendarItem);
+    }
+
+    public Task<int> UpsertCalendarAsync(AccountCalendar calendar)
+    {
+        return _calendarServiceEx.UpsertCalendarAsync(calendar);
+    }
+
+    public Task<int> UpsertEventAsync(CalendarItem calendarItem)
+    {
+        return _calendarServiceEx.UpsertEventAsync(calendarItem);
+    }
+
+    public Task<int> SyncAttendeesForEventAsync(Guid eventId, List<CalendarEventAttendee> attendees)
+    {
+        return _calendarServiceEx.SyncAttendeesForEventAsync(eventId, attendees);
+    }
+
+    #endregion
 }

Wino.Core/Integration/Processors/GmailChangeProcessor.cs

@@ -1,18 +1,13 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Threading.Tasks;
 using Google.Apis.Calendar.v3.Data;
-using Serilog;
 using Wino.Core.Domain.Entities.Calendar;
 using Wino.Core.Domain.Entities.Shared;
 using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.MailItem;
-using Wino.Core.Extensions;
 using Wino.Services;
-using CalendarEventAttendee = Wino.Core.Domain.Entities.Calendar.CalendarEventAttendee;
-using CalendarItem = Wino.Core.Domain.Entities.Calendar.CalendarItem;
 
 namespace Wino.Core.Integration.Processors;
 
@@ -23,7 +18,8 @@ public class GmailChangeProcessor : DefaultChangeProcessor, IGmailChangeProcesso
                                 IMailService mailService,
                                 ICalendarService calendarService,
                                 IAccountService accountService,
-                                IMimeFileService mimeFileService) : base(databaseService, folderService, mailService, calendarService, accountService, mimeFileService)
+                                ICalendarServiceEx calendarServiceEx,
+                                IMimeFileService mimeFileService) : base(databaseService, folderService, mailService, calendarService, accountService, calendarServiceEx, mimeFileService)
     {
 
     }
@@ -35,226 +31,9 @@ public class GmailChangeProcessor : DefaultChangeProcessor, IGmailChangeProcesso
         => MailService.CreateAssignmentAsync(accountId, mailCopyId, remoteFolderId);
 
     public async Task ManageCalendarEventAsync(Event calendarEvent, AccountCalendar assignedCalendar, MailAccount organizerAccount)
-    {
-        var status = calendarEvent.Status;
-
-        var recurringEventId = calendarEvent.RecurringEventId;
-
-        // 1. Canceled exceptions of recurred events are only guaranteed to have recurringEventId, Id and start time.
-        // 2. Updated exceptions of recurred events have different Id, but recurringEventId is the same as parent.
-
-        // Check if we have this event before.
-        var existingCalendarItem = await CalendarService.GetCalendarItemAsync(assignedCalendar.Id, calendarEvent.Id);
-
-        if (existingCalendarItem == null)
-        {
-            CalendarItem parentRecurringEvent = null;
-
-            // Manage the recurring event id.
-            if (!string.IsNullOrEmpty(recurringEventId))
-            {
-                parentRecurringEvent = await CalendarService.GetCalendarItemAsync(assignedCalendar.Id, recurringEventId).ConfigureAwait(false);
-
-                if (parentRecurringEvent == null)
-                {
-                    Log.Information($"Parent recurring event is missing for event. Skipping creation of {calendarEvent.Id}");
-                    return;
-                }
-            }
-
-            // We don't have this event yet. Create a new one.
-            var eventStartDateTimeOffset = GoogleIntegratorExtensions.GetEventDateTimeOffset(calendarEvent.Start);
-            var eventEndDateTimeOffset = GoogleIntegratorExtensions.GetEventDateTimeOffset(calendarEvent.End);
-
-            double totalDurationInSeconds = 0;
-
-            if (eventStartDateTimeOffset != null && eventEndDateTimeOffset != null)
-            {
-                totalDurationInSeconds = (eventEndDateTimeOffset.Value - eventStartDateTimeOffset.Value).TotalSeconds;
-            }
-
-            CalendarItem calendarItem = null;
-
-            if (parentRecurringEvent != null)
-            {
-                // Exceptions of parent events might not have all the fields populated.
-                // We must use the parent event's data for fields that don't exists.
-
-                // Update duration if it's not populated.
-                if (totalDurationInSeconds == 0)
-                {
-                    totalDurationInSeconds = parentRecurringEvent.DurationInSeconds;
-                }
-
-                var organizerMail = GetOrganizerEmail(calendarEvent, organizerAccount);
-                var organizerName = GetOrganizerName(calendarEvent, organizerAccount);
-
-
-                calendarItem = new CalendarItem()
-                {
-                    CalendarId = assignedCalendar.Id,
-                    CreatedAt = DateTimeOffset.UtcNow,
-                    Description = calendarEvent.Description ?? parentRecurringEvent.Description,
-                    Id = Guid.NewGuid(),
-                    StartDate = eventStartDateTimeOffset.Value.DateTime,
-                    StartDateOffset = eventStartDateTimeOffset.Value.Offset,
-                    EndDateOffset = eventEndDateTimeOffset?.Offset ?? parentRecurringEvent.EndDateOffset,
-                    DurationInSeconds = totalDurationInSeconds,
-                    Location = string.IsNullOrEmpty(calendarEvent.Location) ? parentRecurringEvent.Location : calendarEvent.Location,
-
-                    // Leave it empty if it's not populated.
-                    Recurrence = GoogleIntegratorExtensions.GetRecurrenceString(calendarEvent) == null ? string.Empty : GoogleIntegratorExtensions.GetRecurrenceString(calendarEvent),
-                    Status = GetStatus(calendarEvent.Status),
-                    Title = string.IsNullOrEmpty(calendarEvent.Summary) ? parentRecurringEvent.Title : calendarEvent.Summary,
-                    UpdatedAt = DateTimeOffset.UtcNow,
-                    Visibility = string.IsNullOrEmpty(calendarEvent.Visibility) ? parentRecurringEvent.Visibility : GetVisibility(calendarEvent.Visibility),
-                    HtmlLink = string.IsNullOrEmpty(calendarEvent.HtmlLink) ? parentRecurringEvent.HtmlLink : calendarEvent.HtmlLink,
-                    RemoteEventId = calendarEvent.Id,
-                    IsLocked = calendarEvent.Locked.GetValueOrDefault(),
-                    OrganizerDisplayName = string.IsNullOrEmpty(organizerName) ? parentRecurringEvent.OrganizerDisplayName : organizerName,
-                    OrganizerEmail = string.IsNullOrEmpty(organizerMail) ? parentRecurringEvent.OrganizerEmail : organizerMail
-                };
-            }
-            else
-            {
-                // This is a parent event creation.
-                // Start-End dates are guaranteed to be populated.
-
-                if (eventStartDateTimeOffset == null || eventEndDateTimeOffset == null)
-                {
-                    Log.Error("Failed to create parent event because either start or end date is not specified.");
-                    return;
-                }
-
-                calendarItem = new CalendarItem()
-                {
-                    CalendarId = assignedCalendar.Id,
-                    CreatedAt = DateTimeOffset.UtcNow,
-                    Description = calendarEvent.Description,
-                    Id = Guid.NewGuid(),
-                    StartDate = eventStartDateTimeOffset.Value.DateTime,
-                    StartDateOffset = eventStartDateTimeOffset.Value.Offset,
-                    EndDateOffset = eventEndDateTimeOffset.Value.Offset,
-                    DurationInSeconds = totalDurationInSeconds,
-                    Location = calendarEvent.Location,
-                    Recurrence = GoogleIntegratorExtensions.GetRecurrenceString(calendarEvent),
-                    Status = GetStatus(calendarEvent.Status),
-                    Title = calendarEvent.Summary,
-                    UpdatedAt = DateTimeOffset.UtcNow,
-                    Visibility = GetVisibility(calendarEvent.Visibility),
-                    HtmlLink = calendarEvent.HtmlLink,
-                    RemoteEventId = calendarEvent.Id,
-                    IsLocked = calendarEvent.Locked.GetValueOrDefault(),
-                    OrganizerDisplayName = GetOrganizerName(calendarEvent, organizerAccount),
-                    OrganizerEmail = GetOrganizerEmail(calendarEvent, organizerAccount)
-                };
-            }
-
-            // Hide canceled events.
-            calendarItem.IsHidden = calendarItem.Status == CalendarItemStatus.Cancelled;
-
-            // Manage the recurring event id.
-            if (parentRecurringEvent != null)
-            {
-                calendarItem.RecurringCalendarItemId = parentRecurringEvent.Id;
-            }
-
-            Debug.WriteLine($"({assignedCalendar.Name}) {calendarItem.Title}, Start: {calendarItem.StartDate.ToString("f")}, End: {calendarItem.EndDate.ToString("f")}");
-
-            // Attendees
-            var attendees = new List<CalendarEventAttendee>();
-
-            if (calendarEvent.Attendees == null)
-            {
-                // Self-only event.
-
-                attendees.Add(new CalendarEventAttendee()
-                {
-                    CalendarItemId = calendarItem.Id,
-                    IsOrganizer = true,
-                    Email = organizerAccount.Address,
-                    Name = organizerAccount.SenderName,
-                    AttendenceStatus = AttendeeStatus.Accepted,
-                    Id = Guid.NewGuid(),
-                    IsOptionalAttendee = false,
-                });
-            }
-            else
-            {
-                foreach (var attendee in calendarEvent.Attendees)
-                {
-                    if (attendee.Self == true)
     {
         // TODO:
     }
-                    else if (!string.IsNullOrEmpty(attendee.Email))
-                    {
-                        AttendeeStatus GetAttendenceStatus(string responseStatus)
-                        {
-                            return responseStatus switch
-                            {
-                                "accepted" => AttendeeStatus.Accepted,
-                                "declined" => AttendeeStatus.Declined,
-                                "tentative" => AttendeeStatus.Tentative,
-                                "needsAction" => AttendeeStatus.NeedsAction,
-                                _ => AttendeeStatus.NeedsAction
-                            };
-                        }
-
-                        var eventAttendee = new CalendarEventAttendee()
-                        {
-                            CalendarItemId = calendarItem.Id,
-                            IsOrganizer = attendee.Organizer ?? false,
-                            Comment = attendee.Comment,
-                            Email = attendee.Email,
-                            Name = attendee.DisplayName,
-                            AttendenceStatus = GetAttendenceStatus(attendee.ResponseStatus),
-                            Id = Guid.NewGuid(),
-                            IsOptionalAttendee = attendee.Optional ?? false,
-                        };
-
-                        attendees.Add(eventAttendee);
-                    }
-                }
-            }
-
-            await CalendarService.CreateNewCalendarItemAsync(calendarItem, attendees);
-        }
-        else
-        {
-            // We have this event already. Update it.
-            if (calendarEvent.Status == "cancelled")
-            {
-                // Parent event is canceled. We must delete everything.
-                if (string.IsNullOrEmpty(recurringEventId))
-                {
-                    Log.Information("Parent event is canceled. Deleting all instances of {Id}", existingCalendarItem.Id);
-
-                    await CalendarService.DeleteCalendarItemAsync(existingCalendarItem.Id).ConfigureAwait(false);
-
-                    return;
-                }
-                else
-                {
-                    // Child event is canceled.
-                    // Child should live as long as parent lives, but must not be displayed to the user.
-
-                    existingCalendarItem.IsHidden = true;
-                }
-            }
-            else
-            {
-                // Make sure to unhide the event.
-                // It might be marked as hidden before.
-                existingCalendarItem.IsHidden = false;
-
-                // Update the event properties.
-            }
-        }
-
-        // Upsert the event.
-        await Connection.InsertOrReplaceAsync(existingCalendarItem);
-    }
 
     private string GetOrganizerName(Event calendarEvent, MailAccount account)
     {

Wino.Core/Integration/Processors/ImapChangeProcessor.cs

@@ -13,7 +13,8 @@ public class ImapChangeProcessor : DefaultChangeProcessor, IImapChangeProcessor
                                IMailService mailService,
                                IAccountService accountService,
                                ICalendarService calendarService,
-                               IMimeFileService mimeFileService) : base(databaseService, folderService, mailService, calendarService, accountService, mimeFileService)
+                               ICalendarServiceEx calendarServiceEx,
+                               IMimeFileService mimeFileService) : base(databaseService, folderService, mailService, calendarService, accountService, calendarServiceEx, mimeFileService)
     {
     }
 

Wino.Core/Integration/Processors/OutlookChangeProcessor.cs

@@ -1,13 +1,9 @@
 using System;
-using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.Graph.Models;
-using Serilog;
 using Wino.Core.Domain.Entities.Calendar;
 using Wino.Core.Domain.Entities.Shared;
-using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
-using Wino.Core.Extensions;
 using Wino.Services;
 
 namespace Wino.Core.Integration.Processors;
@@ -17,7 +13,8 @@ public class OutlookChangeProcessor(IDatabaseService databaseService,
                                     ICalendarService calendarService,
                                     IMailService mailService,
                                     IAccountService accountService,
-                                    IMimeFileService mimeFileService) : DefaultChangeProcessor(databaseService, folderService, mailService, calendarService, accountService, mimeFileService)
+                                    ICalendarServiceEx calendarServiceEx,
+                                    IMimeFileService mimeFileService) : DefaultChangeProcessor(databaseService, folderService, mailService, calendarService, accountService, calendarServiceEx, mimeFileService)
     , IOutlookChangeProcessor
 {
 
@@ -40,106 +37,6 @@ public class OutlookChangeProcessor(IDatabaseService databaseService,
 
     public async Task ManageCalendarEventAsync(Event calendarEvent, AccountCalendar assignedCalendar, MailAccount organizerAccount)
     {
-        // We parse the occurrences based on the parent event.
-        // There is literally no point to store them because
-        // type=Exception events are the exceptional childs of recurrency parent event.
-
-        if (calendarEvent.Type == EventType.Occurrence) return;
-
-        var savingItem = await CalendarService.GetCalendarItemAsync(assignedCalendar.Id, calendarEvent.Id);
-
-        Guid savingItemId = Guid.Empty;
-
-        if (savingItem != null)
-            savingItemId = savingItem.Id;
-        else
-        {
-            savingItemId = Guid.NewGuid();
-            savingItem = new CalendarItem() { Id = savingItemId };
-        }
-
-        DateTimeOffset eventStartDateTimeOffset = OutlookIntegratorExtensions.GetDateTimeOffsetFromDateTimeTimeZone(calendarEvent.Start);
-        DateTimeOffset eventEndDateTimeOffset = OutlookIntegratorExtensions.GetDateTimeOffsetFromDateTimeTimeZone(calendarEvent.End);
-
-        var durationInSeconds = (eventEndDateTimeOffset - eventStartDateTimeOffset).TotalSeconds;
-
-        savingItem.RemoteEventId = calendarEvent.Id;
-        savingItem.StartDate = eventStartDateTimeOffset.DateTime;
-        savingItem.StartDateOffset = eventStartDateTimeOffset.Offset;
-        savingItem.EndDateOffset = eventEndDateTimeOffset.Offset;
-        savingItem.DurationInSeconds = durationInSeconds;
-
-        savingItem.Title = calendarEvent.Subject;
-        savingItem.Description = calendarEvent.Body?.Content;
-        savingItem.Location = calendarEvent.Location?.DisplayName;
-
-        if (calendarEvent.Type == EventType.Exception && !string.IsNullOrEmpty(calendarEvent.SeriesMasterId))
-        {
-            // This is a recurring event exception.
-            // We need to find the parent event and set it as recurring event id.
-
-            var parentEvent = await CalendarService.GetCalendarItemAsync(assignedCalendar.Id, calendarEvent.SeriesMasterId);
-
-            if (parentEvent != null)
-            {
-                savingItem.RecurringCalendarItemId = parentEvent.Id;
-            }
-            else
-            {
-                Log.Warning($"Parent recurring event is missing for event. Skipping creation of {calendarEvent.Id}");
-                return;
-            }
-        }
-
-        // Convert the recurrence pattern to string for parent recurring events.
-        if (calendarEvent.Type == EventType.SeriesMaster && calendarEvent.Recurrence != null)
-        {
-            savingItem.Recurrence = OutlookIntegratorExtensions.ToRfc5545RecurrenceString(calendarEvent.Recurrence);
-        }
-
-        savingItem.HtmlLink = calendarEvent.WebLink;
-        savingItem.CalendarId = assignedCalendar.Id;
-        savingItem.OrganizerEmail = calendarEvent.Organizer?.EmailAddress?.Address;
-        savingItem.OrganizerDisplayName = calendarEvent.Organizer?.EmailAddress?.Name;
-        savingItem.IsHidden = false;
-
-        if (calendarEvent.ResponseStatus?.Response != null)
-        {
-            switch (calendarEvent.ResponseStatus.Response.Value)
-            {
-                case ResponseType.None:
-                case ResponseType.NotResponded:
-                    savingItem.Status = CalendarItemStatus.NotResponded;
-                    break;
-                case ResponseType.TentativelyAccepted:
-                    savingItem.Status = CalendarItemStatus.Tentative;
-                    break;
-                case ResponseType.Accepted:
-                case ResponseType.Organizer:
-                    savingItem.Status = CalendarItemStatus.Confirmed;
-                    break;
-                case ResponseType.Declined:
-                    savingItem.Status = CalendarItemStatus.Cancelled;
-                    savingItem.IsHidden = true;
-                    break;
-                default:
-                    break;
-            }
-        }
-        else
-        {
-            savingItem.Status = CalendarItemStatus.Confirmed;
-        }
-
-        // Upsert the event.
-        await Connection.InsertOrReplaceAsync(savingItem);
-
-        // Manage attendees.
-        if (calendarEvent.Attendees != null)
-        {
-            // Clear all attendees for this event.
-            var attendees = calendarEvent.Attendees.Select(a => a.CreateAttendee(savingItemId)).ToList();
-            await CalendarService.ManageEventAttendeesAsync(savingItemId, attendees).ConfigureAwait(false);
-        }
+        // TODO
     }
 }

Wino.Core/Synchronizers/GmailSynchronizer.cs

@@ -361,75 +361,207 @@ public class GmailSynchronizer : WinoSynchronizer<IClientServiceRequest, Message
 
         await SynchronizeCalendarsAsync(cancellationToken).ConfigureAwait(false);
 
-        bool isInitialSync = string.IsNullOrEmpty(Account.SynchronizationDeltaIdentifier);
-
-        _logger.Debug("Is initial synchronization: {IsInitialSync}", isInitialSync);
-
         var localCalendars = await _gmailChangeProcessor.GetAccountCalendarsAsync(Account.Id).ConfigureAwait(false);
 
-        // TODO: Better logging and exception handling.
         foreach (var calendar in localCalendars)
         {
-            var request = _calendarService.Events.List(calendar.RemoteCalendarId);
+            // We can do just delta sync. It will fallback to full sync if there are no sync tokens or if the token is expired.
+            await DeltaSynchronizeCalendarAsync(calendar).ConfigureAwait(false);
+        }
 
-            request.SingleEvents = false;
-            request.ShowDeleted = true;
-
-            if (!string.IsNullOrEmpty(calendar.SynchronizationDeltaToken))
+        // TODO: Return proper result from delta or full sync.
+        return new CalendarSynchronizationResult()
         {
-                // If a sync token is available, perform an incremental sync
-                request.SyncToken = calendar.SynchronizationDeltaToken;
+            CompletedState = SynchronizationCompletedState.Success,
+            DownloadedEvents = new List<ICalendarItem>(),
+        };
+    }
+
+    private async Task FullSynchronizeCalendarAsync(AccountCalendar calendar)
+    {
+        var calendarId = calendar.RemoteCalendarId;
+
+        try
+        {
+            // Get events from the last 30 days to 1 year in the future
+            var timeMin = DateTime.Now.AddYears(-3);
+            var timeMax = DateTime.Now.AddYears(2);
+
+            var request = _calendarService.Events.List(calendarId);
+            request.TimeMinDateTimeOffset = timeMin;
+            request.TimeMaxDateTimeOffset = timeMax;
+            request.SingleEvents = false; // Include recurring events
+            request.ShowDeleted = true; // Include deleted events for synchronization
+            request.MaxResults = 2500; // Maximum allowed by Google Calendar API
+
+            var events = await request.ExecuteAsync();
+
+            if (events.Items != null && events.Items.Count > 0)
+            {
+                Console.WriteLine($"Processing {events.Items.Count} events from calendar: {calendarId}");
+
+                foreach (var googleEvent in events.Items)
+                {
+                    await ProcessGoogleEventAsync(googleEvent, calendar);
+                }
             }
             else
             {
-                // If no sync token, perform an initial sync
-                // Fetch events from the past year
-
-                request.TimeMinDateTimeOffset = DateTimeOffset.UtcNow.AddYears(-1);
+                Console.WriteLine($"No events found in calendar: {calendarId}");
             }
 
-            string nextPageToken;
-            string syncToken;
-
-            var allEvents = new List<Event>();
-
-            do
+            // Store the sync token for future delta syncs
+            if (!string.IsNullOrEmpty(events.NextSyncToken))
             {
-                // Execute the request
-                var events = await request.ExecuteAsync();
+                await _gmailChangeProcessor.UpdateCalendarDeltaSynchronizationToken(calendar.Id, events.NextSyncToken).ConfigureAwait(false);
 
-                // Process the fetched events
-                if (events.Items != null)
+                Console.WriteLine($"Stored sync token for calendar {calendarId} to enable delta sync");
+            }
+        }
+        catch (Exception ex)
         {
-                    allEvents.AddRange(events.Items);
+            throw new InvalidOperationException($"Failed to synchronize calendar {calendarId}: {ex.Message}", ex);
+        }
     }
 
-                // Get the next page token and sync token
-                nextPageToken = events.NextPageToken;
-                syncToken = events.NextSyncToken;
-
-                // Set the next page token for subsequent requests
-                request.PageToken = nextPageToken;
-
-            } while (!string.IsNullOrEmpty(nextPageToken));
-
-            calendar.SynchronizationDeltaToken = syncToken;
-
-            // allEvents contains new or updated events.
-            // Process them and create/update local calendar items.
-
-            foreach (var @event in allEvents)
+    private async Task<bool> DeltaSynchronizeCalendarAsync(AccountCalendar calendar)
     {
-                // TODO: Exception handling for event processing.
-                // TODO: Also update attendees and other properties.
+        var calendarId = calendar.RemoteCalendarId;
 
-                await _gmailChangeProcessor.ManageCalendarEventAsync(@event, calendar, Account).ConfigureAwait(false);
+        try
+        {
+            Console.WriteLine($"Starting delta sync for calendar: {calendarId}");
+
+            // Get the stored sync token for this calendar
+            var syncToken = calendar.SynchronizationDeltaToken;
+
+            if (string.IsNullOrEmpty(syncToken))
+            {
+                Console.WriteLine($"No sync token found for calendar {calendarId}. Performing full sync...");
+                await FullSynchronizeCalendarAsync(calendar);
+                return true;
             }
 
-            await _gmailChangeProcessor.UpdateAccountCalendarAsync(calendar).ConfigureAwait(false);
+            // Create the events list request with sync token
+            var request = _calendarService.Events.List(calendarId);
+            request.SyncToken = syncToken;
+            request.ShowDeleted = true; // Important: include deleted events for delta sync
+            request.SingleEvents = false; // Include recurring events
+
+            Console.WriteLine($"Requesting delta changes with sync token: {syncToken.Substring(0, Math.Min(20, syncToken.Length))}...");
+
+            Events events;
+            try
+            {
+                events = await request.ExecuteAsync();
+            }
+            catch (Google.GoogleApiException ex) when (ex.HttpStatusCode == System.Net.HttpStatusCode.Gone)
+            {
+                // Sync token has expired, need to do full sync
+                Console.WriteLine($"Sync token expired for calendar {calendarId}. Performing full sync...");
+                await FullSynchronizeCalendarAsync(calendar);
+                return true;
             }
 
-        return default;
+            if (events.Items != null && events.Items.Count > 0)
+            {
+                Console.WriteLine($"Processing {events.Items.Count} delta changes for calendar: {calendarId}");
+
+                foreach (var googleEvent in events.Items)
+                {
+                    await ProcessDeltaCalendarEventAsync(googleEvent, calendar);
+                }
+            }
+            else
+            {
+                Console.WriteLine($"No changes found for calendar: {calendarId}");
+            }
+
+            // Store the new sync token
+            if (!string.IsNullOrEmpty(events.NextSyncToken))
+            {
+                await _gmailChangeProcessor.UpdateCalendarSyncTokenAsync(calendarId, events.NextSyncToken).ConfigureAwait(false);
+
+                calendar.SynchronizationDeltaToken = events.NextSyncToken;
+                Console.WriteLine($"Updated sync token for calendar {calendarId}");
+            }
+
+            return true;
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Error during delta sync for calendar {calendarId}: {ex.Message}");
+            return false;
+        }
+    }
+
+    /// <summary>
+    /// Processes a single event change from delta synchronization
+    /// </summary>
+    /// <param name="googleEvent">The Google Calendar event</param>
+    /// <param name="calendarId">The ID of the calendar containing the event</param>
+    private async Task ProcessDeltaCalendarEventAsync(Event googleEvent, AccountCalendar calendar)
+    {
+        var calendarId = calendar.RemoteCalendarId;
+
+        try
+        {
+            if (googleEvent.Status == "cancelled")
+            {
+                // Handle deleted/canceled events
+                await _gmailChangeProcessor.MarkEventAsDeletedAsync(googleEvent.Id, calendarId);
+                Console.WriteLine($"🗑️ Marked event as deleted: {googleEvent.Summary ?? googleEvent.Id}");
+                return;
+            }
+
+            // For active events (confirmed, tentative), process normally
+            var calendarEvent = GoogleIntegratorExtensions.MapGoogleEventToCalendarEvent(googleEvent, calendar);
+            var result = await _gmailChangeProcessor.UpsertEventAsync(calendarEvent);
+
+            // Sync attendees for delta events too
+            await SyncEventAttendeesAsync(googleEvent, calendarEvent.Id);
+
+            if (result > 0)
+            {
+                var action = await _gmailChangeProcessor.GetEventByRemoteIdAsync(googleEvent.Id) != null ? "Updated" : "Created";
+                Console.WriteLine($"✅ {action} event: {calendarEvent.Title} ({calendarEvent.RemoteEventId})");
+            }
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"❌ Failed to process delta event {googleEvent.Id}: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    /// Processes a single Google Calendar event and updates the local database
+    /// </summary>
+    /// <param name="googleEvent">The Google Calendar event</param>
+    /// <param name="calendarId">The ID of the calendar containing the event</param>
+    private async Task ProcessGoogleEventAsync(Event googleEvent, AccountCalendar calendar)
+    {
+        try
+        {
+            if (googleEvent.Status == "cancelled")
+            {
+                // Handle deleted events
+                await _gmailChangeProcessor.DeleteEventAsync(googleEvent.Id);
+                Console.WriteLine($"Marked event as deleted: {googleEvent.Summary ?? googleEvent.Id}");
+                return;
+            }
+
+            var calendarEvent = googleEvent.MapGoogleEventToCalendarEvent(calendar);
+            await _gmailChangeProcessor.UpsertEventAsync(calendarEvent);
+
+            // Sync attendees separately
+            await SyncEventAttendeesAsync(googleEvent, calendarEvent.Id);
+
+            Console.WriteLine($"Processed event: {calendarEvent.Title} ({calendarEvent.RemoteEventId})");
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Failed to process event {googleEvent.Id}: {ex.Message}");
+        }
     }
 
     private async Task SynchronizeCalendarsAsync(CancellationToken cancellationToken = default)
@@ -511,6 +643,40 @@ public class GmailSynchronizer : WinoSynchronizer<IClientServiceRequest, Message
         }
     }
 
+    /// <summary>
+    /// Syncs attendees for an event from Google Calendar data
+    /// </summary>
+    /// <param name="googleEvent">The Google Calendar event</param>
+    /// <param name="eventId">The internal event Guid</param>
+    private async Task SyncEventAttendeesAsync(Event googleEvent, Guid eventId)
+    {
+        var attendees = new List<CalendarEventAttendee>();
+
+        if (googleEvent.Attendees != null && googleEvent.Attendees.Count > 0)
+        {
+            foreach (var googleAttendee in googleEvent.Attendees)
+            {
+                var attendee = new CalendarEventAttendee
+                {
+                    EventId = eventId,
+                    Email = googleAttendee.Email ?? string.Empty,
+                    DisplayName = googleAttendee.DisplayName,
+                    ResponseStatus = GoogleIntegratorExtensions.FromGoogleStatus(googleAttendee.ResponseStatus),
+                    IsOptional = googleAttendee.Optional ?? false,
+                    IsOrganizer = googleAttendee.Organizer ?? false,
+                    IsSelf = googleAttendee.Self ?? false,
+                    Comment = googleAttendee.Comment,
+                    AdditionalGuests = googleAttendee.AdditionalGuests
+                };
+
+                attendees.Add(attendee);
+            }
+        }
+
+        // Sync attendees (replaces existing)
+        await _gmailChangeProcessor.SyncAttendeesForEventAsync(eventId, attendees).ConfigureAwait(false);
+    }
+
     private async Task InitializeArchiveFolderAsync()
     {
         var localFolders = await _gmailChangeProcessor.GetLocalFoldersAsync(Account.Id).ConfigureAwait(false);

Wino.Services/CalendarService.cs

@@ -1,16 +1,9 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
-using System.Linq;
-using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using CommunityToolkit.Mvvm.Messaging;
-using Ical.Net.CalendarComponents;
-using Ical.Net.DataTypes;
 using SqlKata;
-using Wino.Core.Domain;
 using Wino.Core.Domain.Entities.Calendar;
-using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Calendar;
 using Wino.Messaging.Client.Calendar;
@@ -58,27 +51,7 @@ public class CalendarService : BaseDatabaseService, ICalendarService
 
     public async Task DeleteCalendarItemAsync(Guid calendarItemId)
     {
-        var calendarItem = await Connection.GetAsync<CalendarItem>(calendarItemId);
 
-        if (calendarItem == null) return;
-
-        List<CalendarItem> eventsToRemove = new() { calendarItem };
-
-        // In case of parent event, delete all child events as well.
-        if (!string.IsNullOrEmpty(calendarItem.Recurrence))
-        {
-            var recurringEvents = await Connection.Table<CalendarItem>().Where(a => a.RecurringCalendarItemId == calendarItemId).ToListAsync().ConfigureAwait(false);
-
-            eventsToRemove.AddRange(recurringEvents);
-        }
-
-        foreach (var @event in eventsToRemove)
-        {
-            await Connection.Table<CalendarItem>().DeleteAsync(x => x.Id == @event.Id).ConfigureAwait(false);
-            await Connection.Table<CalendarEventAttendee>().DeleteAsync(a => a.CalendarItemId == @event.Id).ConfigureAwait(false);
-
-            WeakReferenceMessenger.Default.Send(new CalendarItemDeleted(@event));
-        }
     }
 
     public async Task CreateNewCalendarItemAsync(CalendarItem calendarItem, List<CalendarEventAttendee> attendees)
@@ -98,83 +71,8 @@ public class CalendarService : BaseDatabaseService, ICalendarService
 
     public async Task<List<CalendarItem>> GetCalendarEventsAsync(IAccountCalendar calendar, DayRangeRenderModel dayRangeRenderModel)
     {
-        // TODO: We might need to implement caching here.
-        // I don't know how much of the events we'll have in total, but this logic scans all events every time for given calendar.
-
-        var accountEvents = await Connection.Table<CalendarItem>()
-            .Where(x => x.CalendarId == calendar.Id && !x.IsHidden).ToListAsync();
-
-        var result = new List<CalendarItem>();
-
-        foreach (var ev in accountEvents)
-        {
-            ev.AssignedCalendar = calendar;
-
-            // Parse recurrence rules
-            var calendarEvent = new CalendarEvent
-            {
-                Start = new CalDateTime(ev.StartDate),
-                End = new CalDateTime(ev.EndDate),
-            };
-
-            if (string.IsNullOrEmpty(ev.Recurrence))
-            {
-                // No recurrence, only check if we fall into the given period.
-
-                if (ev.Period.OverlapsWith(dayRangeRenderModel.Period))
-                {
-                    result.Add(ev);
-                }
-            }
-            else
-            {
-                // This event has recurrences.
-                // Wino stores exceptional recurrent events as a separate calendar item, without the recurrence rule.
-                // Because each instance of recurrent event can have different attendees, properties etc.
-                // Even though the event is recurrent, each updated instance is a separate calendar item.
-                // Calculate the all recurrences, and remove the exceptional instances like hidden ones.
-
-                var recurrenceLines = Regex.Split(ev.Recurrence, Constants.CalendarEventRecurrenceRuleSeperator);
-
-                foreach (var line in recurrenceLines)
-                {
-                    calendarEvent.RecurrenceRules.Add(new RecurrencePattern(line));
-                }
-
-                // Calculate occurrences in the range.
-                var occurrences = calendarEvent.GetOccurrences(dayRangeRenderModel.Period.Start, dayRangeRenderModel.Period.End);
-
-                // Get all recurrent exceptional calendar events.
-                var exceptionalRecurrences = await Connection.Table<CalendarItem>()
-                    .Where(a => a.RecurringCalendarItemId == ev.Id)
-                    .ToListAsync()
-                    .ConfigureAwait(false);
-
-                foreach (var occurrence in occurrences)
-                {
-                    var exactInstanceCheck = exceptionalRecurrences.FirstOrDefault(a =>
-                    a.Period.OverlapsWith(dayRangeRenderModel.Period));
-
-                    if (exactInstanceCheck == null)
-                    {
-                        // There is no exception for the period.
-                        // Change the instance StartDate and Duration.
-
-                        var recurrence = ev.CreateRecurrence(occurrence.Period.StartTime.Value, occurrence.Period.Duration.TotalSeconds);
-
-                        result.Add(recurrence);
-                    }
-                    else
-                    {
-                        // There is a single instance of this recurrent event.
-                        // It will be added as single item if it's not hidden.
-                        // We don't need to do anything here.
-                    }
-                }
-            }
-        }
-
-        return result;
+        // TODO
+        return new List<CalendarItem>();
     }
 
     public Task<AccountCalendar> GetAccountCalendarAsync(Guid accountCalendarId)
@@ -221,7 +119,7 @@ public class CalendarService : BaseDatabaseService, ICalendarService
     }
 
     public Task<List<CalendarEventAttendee>> GetAttendeesAsync(Guid calendarEventTrackingId)
-        => Connection.Table<CalendarEventAttendee>().Where(x => x.CalendarItemId == calendarEventTrackingId).ToListAsync();
+        => Connection.Table<CalendarEventAttendee>().Where(x => x.EventId == calendarEventTrackingId).ToListAsync();
 
     public async Task<List<CalendarEventAttendee>> ManageEventAttendeesAsync(Guid calendarItemId, List<CalendarEventAttendee> allAttendees)
     {
@@ -230,7 +128,7 @@ public class CalendarService : BaseDatabaseService, ICalendarService
             // Clear all attendees.
             var query = new Query()
                 .From(nameof(CalendarEventAttendee))
-                .Where(nameof(CalendarEventAttendee.CalendarItemId), calendarItemId)
+                .Where(nameof(CalendarEventAttendee.EventId), calendarItemId)
                 .AsDelete();
 
             connection.Execute(query.GetRawQuery());
@@ -239,67 +137,12 @@ public class CalendarService : BaseDatabaseService, ICalendarService
             connection.InsertAll(allAttendees);
         });
 
-        return await Connection.Table<CalendarEventAttendee>().Where(a => a.CalendarItemId == calendarItemId).ToListAsync();
+        return await Connection.Table<CalendarEventAttendee>().Where(a => a.EventId == calendarItemId).ToListAsync();
     }
 
     public async Task<CalendarItem> GetCalendarItemTargetAsync(CalendarItemTarget targetDetails)
     {
-        var eventId = targetDetails.Item.Id;
-
-        // Get the event by Id first.
-        var item = await GetCalendarItemAsync(eventId).ConfigureAwait(false);
-
-        bool isRecurringChild = targetDetails.Item.IsRecurringChild;
-        bool isRecurringParent = targetDetails.Item.IsRecurringParent;
-
-        if (targetDetails.TargetType == CalendarEventTargetType.Single)
-        {
-            if (isRecurringChild)
-            {
-                if (item == null)
-                {
-                    // This is an occurrence of a recurring event.
-                    // They don't exist in db.
-
-                    return targetDetails.Item;
-                }
-                else
-                {
-                    // Single exception occurrence of recurring event.
-                    // Return the item.
-
-                    return item;
-                }
-            }
-            else if (isRecurringParent)
-            {
-                // Parent recurring events are never listed.
-                Debugger.Break();
-                return null;
-            }
-            else
-            {
-                // Single event.
-                return item;
-            }
-        }
-        else
-        {
-            // Series.
-
-            if (isRecurringChild)
-            {
-                // Return the parent.
-                return await GetCalendarItemAsync(targetDetails.Item.RecurringCalendarItemId.Value).ConfigureAwait(false);
-            }
-            else if (isRecurringParent)
-                return item;
-            else
-            {
-                // NA. Single events don't have series.
-                Debugger.Break();
+        // TODO
         return null;
     }
 }
-    }
-}

Wino.Services/ServicesContainerSetup.cs

@@ -17,6 +17,7 @@ public static class ServicesContainerSetup
         services.AddSingleton<IMimeFileService, MimeFileService>();
 
         services.AddTransient<ICalendarService, CalendarService>();
+        services.AddTransient<ICalendarServiceEx, CalendarServiceEx>();
         services.AddTransient<IMailService, MailService>();
         services.AddTransient<IFolderService, FolderService>();
         services.AddTransient<IAccountService, AccountService>();
@@ -29,7 +30,5 @@ public static class ServicesContainerSetup
         services.AddTransient<IOutlookThreadingStrategy, OutlookThreadingStrategy>();
         services.AddTransient<IGmailThreadingStrategy, GmailThreadingStrategy>();
         services.AddTransient<IImapThreadingStrategy, ImapThreadingStrategy>();
-
-
     }
 }