namespace Melskin.Controls;
/// <summary>
/// 表示一个可关闭的标签控件。
/// </summary>
[TemplatePart(Name = PART_Close, Type = typeof(UIElement))]
public class Tag : System.Windows.Controls.ContentControl
{
    #region Fileds
    private const string PART_Close = "PART_Close";

    private UIElement? close;
    #endregion

    #region Events

    /// <summary>
    /// 当标签即将关闭时触发的路由事件。
    /// </summary>
    public static readonly RoutedEvent ClosingEvent =
        EventManager.RegisterRoutedEvent("Closing", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(Tag));

    /// <summary>
    /// Occurs when closing the tag.
    /// </summary>
    public event RoutedEventHandler Closing
    {
        add => AddHandler(ClosingEvent, value);
        remove => RemoveHandler(ClosingEvent, value);
    }

    /// <summary>
    /// 当标签关闭后触发的路由事件。
    /// </summary>
    public static readonly RoutedEvent ClosedEvent =
        EventManager.RegisterRoutedEvent("Closed", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(Tag));

    /// <summary>
    /// Occurs when a Tag is closed and is no longer visible.
    /// </summary>
    public event RoutedEventHandler Closed
    {
        add => AddHandler(ClosedEvent, value);
        remove => RemoveHandler(ClosedEvent, value);
    }
    #endregion

    #region Properties

    /// <summary>
    /// 表示标签是否可以关闭的依赖属性。
    /// </summary>
    public static readonly DependencyProperty ClosableProperty =
        DependencyProperty.Register(
        nameof(Closable),
        typeof(bool),
        typeof(Tag),
        new PropertyMetadata(false/*, OnClosableChnaged*/));

    /// <summary>
    /// Gets/sets whether the Tag can be closed.
    /// </summary>
    public bool Closable
    {
        get => (bool)GetValue(ClosableProperty);
        set => SetValue(ClosableProperty, value);
    }

    //private static void OnClosableChnaged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    //{
    //    (d as Tag).SetCloseVisibility();
    //}

    //private void SetCloseVisibility()
    //{
    //    if (close != null)
    //    {
    //        close.Visibility = Closable ? Visibility.Visible : Visibility.Collapsed;
    //    }
    //}

    #endregion

    #region Constructors
    static Tag() { DefaultStyleKeyProperty.OverrideMetadata(typeof(Tag), new FrameworkPropertyMetadata(typeof(Tag))); }
    #endregion

    #region Overrides

    /// <inheritdoc />
    public override void OnApplyTemplate()
    {
        base.OnApplyTemplate();

        if (close != null)
        {
            close.MouseLeftButtonUp -= OnRaiseClosingEvent;
            close.PreviewMouseLeftButtonDown -= Close_PreviewMouseLeftButtonDown;
        }

        close = GetTemplateChild(PART_Close) as UIElement;

        if (close != null)
        {
            Loaded -= OnLoaded;
            Loaded += OnLoaded;

            close.PreviewMouseLeftButtonDown += Close_PreviewMouseLeftButtonDown; //阻止ComboBox的ToggleButton切换
            close.MouseLeftButtonUp += OnRaiseClosingEvent;
        }
    }

    private void Close_PreviewMouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
    {
        // 阻止事件继续向上隧道到 ToggleButton
        e.Handled = true;
    }

    private void OnLoaded(object sender, RoutedEventArgs e)
    {
        Closing -= OnClosing;
        Closing += OnClosing;
    }

    private void OnRaiseClosingEvent(object sender, RoutedEventArgs e)
    {
        e.Handled = true;
        RaiseEvent(new RoutedEventArgs(ClosingEvent, this));
    }

    private void OnClosing(object sender, RoutedEventArgs e)
    {
        SetCurrentValue(VisibilityProperty, Visibility.Collapsed);
        RaiseEvent(new RoutedEventArgs(ClosedEvent, this));
    }
    #endregion
}