using System.Text.RegularExpressions;
using System.Windows.Input;
using Xceed.Wpf.Toolkit;

namespace BreCalClient
{
    public class DateTimePickerExt : DateTimePicker
    {
        protected override void OnPreviewTextInput(TextCompositionEventArgs e)
        {
            base.OnPreviewTextInput(e);
                        
            // Die vom Agenten "vorgeschlagene" Zeit könnte auch der Watermark sein?

            string text = this.Text + e.Text;
            if (this.Template.FindName("PART_TextBox", this) is not WatermarkTextBox tb) return;

            if (Regex.IsMatch(text, @"^\d{3}"))
            {
                e.Handled = true;
                tb.Text = Regex.Replace(text, @"(\d{2})(\d)", "$1.$2");
                tb.CaretIndex = tb.Text.Length;
            }
            else if (Regex.IsMatch(text, @"^(\d{2}\.\d{3})"))
            {
                e.Handled = true;
                tb.Text = Regex.Replace(text, @"^(\d{2}\.\d{2})(\d)", "$1.$2");
                tb.CaretIndex = tb.Text.Length;
            }
            else if (Regex.IsMatch(text, @"^(\d{2}\.\d{2}\.\d{2} \d{3})"))
            {
                e.Handled = true;
                tb.Text = Regex.Replace(text, @"(\d{2}\.\d{2}\.\d{2} \d{2})(\d)", "$1:$2");
                tb.CaretIndex = tb.Text.Length;
            }
            else if (Regex.IsMatch(text, @"^(\d{2}\.\d{2}\.\d{4} \d{3})"))
            {
                e.Handled = true;
                tb.Text = Regex.Replace(text, @"(\d{2}\.\d{2}\.\d{4} \d{2})(\d)", "$1:$2");
                tb.CaretIndex = tb.Text.Length;
            }
        }
    }
}