namespace Melskin.Controls;

using System.Windows;


/// <summary>
/// A spinner for displaying loading state of a page or a section.
/// </summary>
[TemplateVisualState(Name = "Spun", GroupName = "SpinStates")]
[TemplateVisualState(Name = "Unspun", GroupName = "SpinStates")]
public class Spin : ContentControl
{
    #region Properties

    /// <summary>
    /// 获取或设置指示器属性的依赖属性。此属性用于定义旋转控件中使用的指示器元素。
    /// </summary>
    public static readonly DependencyProperty IndicatorProperty =
        DependencyProperty.Register(
        nameof(Indicator),
        typeof(UIElement),
        typeof(Spin),
        new PropertyMetadata(null, OnSpinningChanged));

    /// <summary>
    /// 获取或设置指示器元素。
    /// </summary>
    public UIElement Indicator
    {
        get => (UIElement)GetValue(IndicatorProperty);
        set => SetValue(IndicatorProperty, value);
    }

    /// <summary>
    /// 获取或设置一个布尔值，指示旋转控件是否处于旋转状态。
    /// </summary>
    public static readonly DependencyProperty SpinningProperty =
        DependencyProperty.Register(
        nameof(Spinning),
        typeof(bool),
        typeof(Spin),
        new PropertyMetadata(true, OnSpinningChanged));

    /// <summary>
    /// 获取或设置是否正在旋转。
    /// </summary>
    public bool Spinning { get => (bool)GetValue(SpinningProperty);
        set => SetValue(SpinningProperty, value);
    }

    private static void OnSpinningChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    { (d as Spin)?.GoToSpinState(); }

    private void GoToSpinState()
    { VisualStateManager.GoToState(this, Spinning && null == Indicator ? "Spun" : "Unspun", true); }

    /// <summary>
    /// 获取或设置提示文本。
    /// </summary>
    public static readonly DependencyProperty TipProperty =
        DependencyProperty.Register(nameof(Tip), typeof(string), typeof(Spin), new PropertyMetadata(string.Empty));

    /// <summary>
    /// 获取或设置提示文本。
    /// </summary>
    public string Tip { get => (string)GetValue(TipProperty);
        set => SetValue(TipProperty, value);
    }
    #endregion

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

    #region Overrides

    /// <inheritdoc />
    public override void OnApplyTemplate()
    {
        base.OnApplyTemplate();
        GoToSpinState();
    }
    #endregion
}