DiscordChatExporter/DiscordChatExporter.Gui/Converters/TimeSpanToDateTimeConverter.cs

using System;
using System.Globalization;
using System.Windows.Data;

namespace DiscordChatExporter.Gui.Converters
{
    [ValueConversion(typeof(TimeSpan?), typeof(DateTime?))]
    public class TimeSpanToDateTimeConverter : IValueConverter
    {
        public static TimeSpanToDateTimeConverter Instance { get; } = new TimeSpanToDateTimeConverter();

        public object? Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is TimeSpan timeSpanValue)
                return DateTime.Today.Add(timeSpanValue);

            return default(DateTime?);
        }

        public object? ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is DateTime dateTimeValue)
                return dateTimeValue.TimeOfDay;

            return default(TimeSpan?);
        }
    }
}