Wino-Mail/Wino.Calendar/Helpers/CalendarXamlHelpers.cs

using System.Linq;
using System.Text.RegularExpressions;
using Ical.Net.CalendarComponents;
using Ical.Net.DataTypes;
using Windows.UI.Xaml.Controls.Primitives;
using Wino.Calendar.ViewModels.Data;
using Wino.Core.Domain;
using Wino.Core.Domain.Collections;
using Wino.Core.Domain.Enums;
using Wino.Core.Domain.Models.Calendar;
using Wino.Helpers;

namespace Wino.Calendar.Helpers;

public static class CalendarXamlHelpers
{
    public static CalendarItemViewModel GetFirstAllDayEvent(CalendarEventCollection collection)
        => (CalendarItemViewModel)collection.AllDayEvents.FirstOrDefault();

    /// <summary>
    /// Returns full date + duration info in Event Details page details title.
    /// </summary>
    public static string GetEventDetailsDateString(CalendarItemViewModel calendarItemViewModel, CalendarSettings settings)
    {
        if (calendarItemViewModel == null || settings == null) return string.Empty;

        var start = calendarItemViewModel.Period.Start;
        var end = calendarItemViewModel.Period.End;

        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)
        {
            return $"{start.ToString($"dd MMMM ddd {timeFormat}", settings.CultureInfo)} - {end.ToString($"dd MMMM ddd {timeFormat}", settings.CultureInfo)}";
        }
        else
        {
            return $"{start.ToString(dateFormat, settings.CultureInfo)} - {end.ToString(timeFormat, settings.CultureInfo)}";
        }
    }

    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}.";
    }

    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})";
        }
    }

    public static PopupPlacementMode GetDesiredPlacementModeForEventsDetailsPopup(
        CalendarItemViewModel calendarItemViewModel,
        CalendarDisplayType calendarDisplayType)
    {
        if (calendarItemViewModel == null) return PopupPlacementMode.Auto;

        // All and/or multi day events always go to the top of the screen.
        if (calendarItemViewModel.IsAllDayEvent || calendarItemViewModel.IsMultiDayEvent) return PopupPlacementMode.Bottom;

        return XamlHelpers.GetPlaccementModeForCalendarType(calendarDisplayType);
    }
}