using System;
using System.Threading;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.EnhancedTouch;
using UnityEngine.UIElements;
using Touch = UnityEngine.InputSystem.EnhancedTouch.Touch;
#if UNITY_EDITOR
using UnityEditor;
#endif
namespace BITKit.UX
{
	[Serializable]
	public class AllowTouchWhenPointerNotOverUI : ICondition
	{
		public bool OnCheck() => UXAllowTouch.Singleton.AllowTouch;
	}
	/*
	 * 当指针进入区域时启用输入
	 * 当指针离开区域时禁用输入,直到所有设备都没有按下,才会再次启用输入
	*/
	/// <summary>
	/// Allow touch when pointer not over UI
	/// </summary>
	public class UXAllowTouch : UXElement<VisualElement>, ICondition
	{
		internal static UXAllowTouch Singleton { get; private set; }
		public bool AllowTouch;
		internal bool IsHoveringUI { get; private set; }
		public bool IsTouching { get; private set; }
		private int updateRequest;
		private CancellationTokenSource cancellationTokenSource;
	
		public override void OnAwake()
		{
			Singleton = this;
			EnhancedTouchSupport.Enable();
			Touch.onFingerUp += OnFingerUp;
			Touch.onFingerDown += OnFingerDown;
			cancellationTokenSource = new CancellationTokenSource();
		}

		private void OnDestroy()
		{
			cancellationTokenSource.Cancel();
		}

		private async void OnFingerDown(Finger obj)
		{
			IsTouching = true;
			try
			{
				await Task.Delay(TimeSpan.FromSeconds(Time.deltaTime*2));
				AllowTouch = !IsHoveringUI;
			}
			catch (OperationCanceledException)
			{
				
			}
		}



		private void OnFingerUp(Finger obj)
		{
			IsTouching = false;
		}

		public override void OnStart()
		{
			base.OnStart();
			visualElement.RegisterCallback<PointerEnterEvent>(OnPointerEnter);
			visualElement.RegisterCallback<PointerLeaveEvent>(OnPointerLevel);
		}

		private void OnPointerLevel(PointerLeaveEvent evt)
		{
			IsHoveringUI = true;
			if (isMouseInput) AllowTouch = false;
		}
		private void OnPointerEnter(PointerEnterEvent evt)
		{
			IsHoveringUI = false;
			if (isMouseInput) AllowTouch = true;
		}

		public bool OnCheck() => AllowTouch;
		private bool isMouseInput => Mouse.current?.delta.ReadValue().sqrMagnitude > 0;
	}
#if UNITY_EDITOR
	[CustomEditor(typeof(UXAllowTouch))]
	public class UXAllowTouchInspector:BITInspector<UXAllowTouch>
	{
		private Label allowTouchLabel;
		private Label isHoveringUILabel;
		private Label isTouching;
		public override VisualElement CreateInspectorGUI()
		{
			FillDefaultInspector();
			CreateSubTitle("Editor");

			allowTouchLabel = root.Create<Label>();
			isHoveringUILabel = root.Create<Label>();
			isTouching = root.Create<Label>();
			
			return root;
		}

		protected override void OnUpdate()
		{
			if (allowTouchLabel is null) return;
			
			allowTouchLabel.text = agent.AllowTouch?"Allow Touch":"Block Touch";
			isHoveringUILabel.text = agent.IsHoveringUI ? "Is Hovering UI" : "Not Hovering UI";
			isTouching.text = agent.IsTouching ? "Is Touching" : "Not Touching";

			allowTouchLabel.style.color = agent.AllowTouch?Color.green:Color.red;
			isHoveringUILabel.style.color = agent.IsHoveringUI?Color.red:Color.green;
			isTouching.style.color = agent.IsTouching?Color.green:Color.red;
		}
	}
	#endif
}