using System;
using System.Collections;
using System.Collections.Generic;
using System.Threading;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.Serialization;
using UnityEngine.UIElements;
// ReSharper disable MemberCanBeProtected.Global
// ReSharper disable ClassWithVirtualMembersNeverInherited.Global
// ReSharper disable UnusedMember.Global

namespace BITKit.UX
{
	public class UIToolKitPanel : MonoBehaviour,IUXPanel
	{
		public const string USSEntry = "transition_entry";
		public const string USSEntryAsync = "transition_entry_async";
		public const string USSEntered = "transition_entried";
		public const string USSExit = "transition_exit";
		public const string USSExitAsync = "transition_exit_async";
		public const string USSExited = "transition_exited";
		
		[RuntimeInitializeOnLoadMethod]
		private static void Reload()
		{
			
			inputActionGroup = new InputActionGroup
			{
				allowGlobalActivation = false,
				Source = nameof(UIToolKitPanel)
			};
			inputActionGroup.allowInput.AddElement(0);
		}
		public UIToolKitPanel()
		{
			Index = GetType().FullName;
		}
		[Header(Constant.Header.Components)]
		[SerializeField] protected UIDocument document;

		[Header(Constant.Header.Settings)]
		[SerializeField, ReadOnly] private bool isActive;
		//[SerializeField,ReadOnly] private float currentOpacity;
		[Header(Constant.Header.Settings)]
		[SerializeField] private bool isWindow;
		[SerializeField] private bool closeWhenClickOutside;
		[SerializeField] private bool isAnimate;
		[SerializeField] private bool allowCursor;
		[SerializeField] private bool allowInput;
		[SerializeField] private bool autoEntry;
		
		[Header(Constant.Header.Settings)]
		[SerializeField] private Optional<float> entryDuration;
		[SerializeField] private Optional<float> exitDuration;
		protected static InputActionGroup inputActionGroup = new()
		{
			allowGlobalActivation = false,
			Source = nameof(UIToolKitPanel)
		};
		public bool IsWindow => isWindow;
		public bool IsAnimate => isAnimate;
		public bool IsValid => destroyCancellationToken.IsCancellationRequested;
		public string Index { get; private set; } 
		public bool AllowCursor => allowCursor;
		public bool AllowInput => allowInput;
		protected float TargetOpacity { get; private set; }
		protected virtual VisualElement background => document.rootVisualElement;
		// protected float CurrentOpacity
		// {
		// 	get => background?.GetOpacity() ?? currentOpacity;
		// 	set	
		// 	{
		// 		currentOpacity = value;
		// 		background?.SetOpacity(value);
		// 	}
		// }
	
		protected virtual void Awake()
		{
			Index= typeof(UIToolKitPanel) == GetType() ? gameObject.name : GetType().Name;
			document.rootVisualElement.SetActive(false);
			//background?.SetOpacity(0);
			if (IsWindow) document.sortingOrder++;
		}

		protected virtual void Start()
		{
			BITKit.UX.UXUtils.Inject(this);
			
			document.rootVisualElement.AddToClassList(USSEntry);

			UXService.Register(this);
			destroyCancellationToken.Register(() => { UXService.UnRegister(this); });

			if (IsValid && autoEntry)
				UXService.Entry(this);

			var returnButton = document.rootVisualElement.Q("return-button");
			returnButton?.RegisterCallback<MouseDownEvent>(x =>
			{
				if (x.button is 0)
					OnReturn();
			});

			var invisible = document.rootVisualElement.Create<VisualElement>();
			invisible.name = "invisible_return_generate";
			invisible.style.position = Position.Absolute;
			invisible.pickingMode = PickingMode.Ignore;
			invisible.style.left = 0;
			invisible.style.right = 0;
			invisible.style.top = 0;
			invisible.style.bottom = 0;
			invisible.SendToBack();

			if (closeWhenClickOutside)
			{
				invisible.RegisterCallback<MouseDownEvent>(x => { OnReturn(); });
				invisible.pickingMode = PickingMode.Position;
			}
			if (isWindow)
			{
				invisible.style.backgroundColor = new Color(0, 0, 0, 0.9f);
			}
		}

		public bool IsEntered { get; set; }
		[BIT]
		public void Entry()
		{
			UXService.Entry(this);
		}
		protected virtual void OnReturn()
		{
			UXService.Return();
		}
		protected virtual void OnEnable(){}
		protected virtual void OnDisable(){}
		protected virtual void OnPanelEntry(){}
		protected virtual void OnPanelExit(){}
        void IEntryElement.Entry()
        {
	        try
	        {
		        //CurrentOpacity = 0;
		        //TargetOpacity = 1f;
		      
		        document.rootVisualElement.SetActive(true);
		     
		        OnEntry?.Invoke();
	        }
	        catch (Exception e)
	        {
		        Debug.Log(gameObject.name);
		        throw;
	        }
	        isActive = true;
		}

		async UniTask IEntryElement.EntryAsync()
        {
	        document.rootVisualElement.AddToClassList(USSEntry);

	        // for (var i = 0; i < 32; i++)
	        // {
		       //  await UniTask.NextFrame();
	        // }
	        
	        document.rootVisualElement.AddToClassList(USSEntryAsync);

	        if (entryDuration.Allow)
	        {
		        var task = EntryAsync();
		        var durationTask = UniTask.Delay(TimeSpan.FromSeconds(entryDuration.Value), cancellationToken: destroyCancellationToken);

		        await durationTask;
		        document.rootVisualElement.RemoveFromClassList(USSEntry);
		        document.rootVisualElement.RemoveFromClassList(USSEntryAsync);
		        document.rootVisualElement.AddToClassList(USSEntered);

		        await task;
	        }
	        else
	        {
		        await EntryAsync();
	        }
        }
        public virtual UniTask EntryAsync()
        {
	        return UniTask.CompletedTask;
        }
        void IEntryElement.Entered()
        {
	     
	        //inputActionGroup.allowInput.AddElement(this);
	        OnPanelEntry();
        }

        void IEntryElement.Exit()
		{
			document.rootVisualElement.AddToClassList(USSExit);
			if (IsValid is false) return;
			//TargetOpacity = 0;
			//inputActionGroup.allowInput.RemoveElement(this);
			OnPanelExit();
		}
		async UniTask IEntryElement.ExitAsync()
		{
			document.rootVisualElement.RemoveFromClassList(USSEntered);
			document.rootVisualElement.AddToClassList(USSExitAsync);
			// if (exitDuration.Allow is false) return;
			// while (CurrentOpacity > 0 && TargetOpacity is 0)
			// {
			// 	await UniTask.NextFrame(cancellationToken);
			// }
			if (entryDuration.Allow is false) return;
			await UniTask.Delay(TimeSpan.FromSeconds(entryDuration.Value), cancellationToken: destroyCancellationToken);
			//return UniTask.CompletedTask;
		}
        void IEntryElement.Exited()
		{
			document.rootVisualElement.RemoveFromClassList(USSExit);
			document.rootVisualElement.RemoveFromClassList(USSExitAsync);
			document.rootVisualElement.AddToClassList(USSEntry);
			document.rootVisualElement.SetActive(false);
			isActive = false;
			OnExit?.Invoke();
		}

		public event Action OnEntry;
		public event Action OnExit;
		public virtual void OnUpdate(float deltaTime)
		{
			// var duration = 1f;
			// if (TargetOpacity is not 0)
			// {
			// 	if (entryDuration.Allow is false)
			// 	{
			// 		CurrentOpacity = TargetOpacity;
			// 		return;
			// 	}
			// 	duration = entryDuration.Value;
			// }
			// else
			// {
			// 	if (exitDuration.Allow is false)
			// 	{
			// 		CurrentOpacity = TargetOpacity;
			// 		return;
			// 	}
			// 	duration = exitDuration.Value;
			// }
			// CurrentOpacity = Mathf.MoveTowards(CurrentOpacity,TargetOpacity,1f/duration * Time.deltaTime);
		}
	}

}