using System.Windows;
using System.Windows.Controls;

namespace EmbyToolbox.Behaviors;

public static class TextBoxAutoScrollBehavior
{
    public static readonly DependencyProperty AutoScrollToEndProperty =
        DependencyProperty.RegisterAttached(
            "AutoScrollToEnd",
            typeof(bool),
            typeof(TextBoxAutoScrollBehavior),
            new PropertyMetadata(false, OnAutoScrollToEndChanged));

    public static bool GetAutoScrollToEnd(DependencyObject obj)
    {
        return (bool)obj.GetValue(AutoScrollToEndProperty);
    }

    public static void SetAutoScrollToEnd(DependencyObject obj, bool value)
    {
        obj.SetValue(AutoScrollToEndProperty, value);
    }

    private static void OnAutoScrollToEndChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is not TextBox textBox)
        {
            return;
        }

        if ((bool)e.NewValue)
        {
            textBox.TextChanged += OnTextBoxTextChanged;
            textBox.ScrollToEnd();
        }
        else
        {
            textBox.TextChanged -= OnTextBoxTextChanged;
        }
    }

    private static void OnTextBoxTextChanged(object sender, TextChangedEventArgs e)
    {
        if (sender is TextBox textBox)
        {
            textBox.ScrollToEnd();
        }
    }
}