using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Media.Effects;

namespace _29WxOrderWpf.ToolCtrls;

public enum ToastType { Info, Success, Warning, Error }

/// <summary>
/// 在指定 Window 内显示自动消失的提示框(Toast)
/// 用法:ToastHelper.Show(window, "保存成功", ToastType.Success);
/// </summary>
public static class ToastHelper
{
	// 每个 Window 对应一个提示容器,用于多个提示堆叠
	private static readonly ConditionalWeakTable<Window, ToastAdorner> Hosts = new();
	private static SolidColorBrush msgBrush;
	static ToastHelper()
	{
		msgBrush = Application.Current.Resources["pageColorBrush"] as SolidColorBrush;
		msgBrush = Application.Current.Resources["pageColorBrush"] as SolidColorBrush;
	}
	/// <param name="owner">要展示提示的窗口</param>
	/// <param name="message">提示内容</param>
	/// <param name="type">类型(决定背景色)</param>
	/// <param name="durationMs">停留时长(毫秒,不含淡入淡出)</param>
	public static void Show(Window owner, string message,
							ToastType type = ToastType.Info, int durationMs = 2000)
	{
		if (owner == null || string.IsNullOrEmpty(message)) return;

		// 允许在非 UI 线程调用
		if (!owner.Dispatcher.CheckAccess())
		{
			owner.Dispatcher.BeginInvoke(new Action(() => Show(owner, message, type, durationMs)));
			return;
		}

		// 窗口还没加载完,等加载后再显示
		if (!owner.IsLoaded)
		{
			RoutedEventHandler handler = null;
			handler = (s, e) =>
			{
				owner.Loaded -= handler;
				Show(owner, message, type, durationMs);
			};
			owner.Loaded += handler;
			return;
		}

		if (owner.Content is not UIElement content) return;
		var layer = AdornerLayer.GetAdornerLayer(content);
		if (layer == null) return;

		if (!Hosts.TryGetValue(owner, out var host))
		{
			host = new ToastAdorner(content);
			layer.Add(host);
			Hosts.Add(owner, host);
		}

		var toast = CreateToast(message, type);
		host.Panel.Children.Add(toast);

		// 淡入 -> 停留 -> 淡出
		var fadeIn = TimeSpan.FromMilliseconds(250);
		var fadeOut = TimeSpan.FromMilliseconds(400);
		var hold = TimeSpan.FromMilliseconds(Math.Max(durationMs, 0));

		var anim = new DoubleAnimationUsingKeyFrames();
		anim.KeyFrames.Add(new LinearDoubleKeyFrame(0, TimeSpan.Zero));
		anim.KeyFrames.Add(new LinearDoubleKeyFrame(1, fadeIn));
		anim.KeyFrames.Add(new LinearDoubleKeyFrame(1, fadeIn + hold));
		anim.KeyFrames.Add(new LinearDoubleKeyFrame(0, fadeIn + hold + fadeOut));
		anim.Completed += (s, e) =>
		{
			host.Panel.Children.Remove(toast);
			if (host.Panel.Children.Count == 0)
			{
				layer.Remove(host);
				Hosts.Remove(owner);
			}
		};
		toast.BeginAnimation(UIElement.OpacityProperty, anim);
	}
	public static void Show(string message,
							ToastType type = ToastType.Info, int durationMs = 2000)
	{
		Window window = Application.Current.Windows
			.OfType<Window>()
			.FirstOrDefault(w => w.IsActive) ?? Application.Current.MainWindow;
		Show(window, message, type, durationMs);
	}
	private static Border CreateToast(string message, ToastType type)
	{
		var color = type switch
		{
			ToastType.Success => Color.FromRgb(0x2E, 0x9E, 0x5B),
			ToastType.Warning => Color.FromRgb(0xE6, 0x9A, 0x1A),
			ToastType.Error => Color.FromRgb(0xD9, 0x4A, 0x4A),
			_ => msgBrush.Color,//Color.FromRgb(0x40, 0x40, 0x40),
		};

		return new Border
		{
			Background = new SolidColorBrush(color),
			CornerRadius = new CornerRadius(6),
			Padding = new Thickness(18, 10, 18, 10),
			Margin = new Thickness(0, 0, 0, 8),
			Opacity = 0,
			MaxWidth = 480,
			Effect = new DropShadowEffect
			{
				BlurRadius = 12,
				ShadowDepth = 2,
				Opacity = 0.3,
				Color = Colors.Black
			},
			Child = new TextBlock
			{
				Text = message,
				Foreground = Brushes.White,
				FontSize = 14,
				TextWrapping = TextWrapping.Wrap
			}
		};
	}

	/// <summary>覆盖在窗口内容上方的提示容器,顶部居中</summary>
	private sealed class ToastAdorner : Adorner
	{
		public StackPanel Panel { get; }

		public ToastAdorner(UIElement adornedElement) : base(adornedElement)
		{
			IsHitTestVisible = false; // 不拦截鼠标事件
			Panel = new StackPanel { Orientation = Orientation.Vertical };
			AddVisualChild(Panel);
		}

		protected override int VisualChildrenCount => 1;
		protected override Visual GetVisualChild(int index) => Panel;

		protected override Size MeasureOverride(Size constraint)
		{
			Panel.Measure(constraint);
			return AdornedElement.RenderSize;
		}

		protected override Size ArrangeOverride(Size finalSize)
		{
			var size = Panel.DesiredSize;
			double x = (finalSize.Width - size.Width) / 2;
			Panel.Arrange(new Rect(new Point(Math.Max(x, 0), 30), size)); // 距顶部 30
			return finalSize;
		}
	}
}