using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using BITKit;
using BITKit.UX;
using UnityEngine;
using UnityEngine.UIElements;

namespace BITKit.UX
{
	[Serializable]
	public class UXPopupSelector:IUXPopup
	{
		[SerializeReference,SubclassSelector] private IReference popupPath;
		public void Popup(string content, float duration = 3)
		{
			UXPopup.Dictionary[popupPath.Value].Popup(content,duration);
		}
	}
	public sealed class UXPopup : MonoBehaviour,IUXPopup
	{
		internal static readonly Dictionary<string,UXPopup> Dictionary=new();
		
		[SerializeField] private UIDocument document;
		[SerializeReference, SubclassSelector] private IReference containerPath;
		[SerializeReference, SubclassSelector] private IReference popupPath;
		[SerializeField] private VisualTreeAsset popupTemplate;

		private VisualElement container;

		private readonly List<ViewModel> instances = new();
			
			private class ViewModel
			{
				public VisualElement visualElement;
				public float exitTime;
				public bool disposed;
			}
			
		private void Start()
		{
			container = document.rootVisualElement.Q<VisualElement>(containerPath.Value);
			
			Dictionary.Add(popupPath.Value,this);
			
			destroyCancellationToken.Register(() => Dictionary.Remove(popupPath.Value));
			
			container.Clear();
		}

		private void Update()
		{
			foreach (var x in instances.Where(x=>Time.time > x.exitTime))
			{
				x.visualElement.RemoveFromHierarchy();
				x.visualElement.SetOpacity(
					Mathf.MoveTowards(x.visualElement.GetOpacity(),0,Time.deltaTime)
					);
				x.disposed = x.visualElement.GetOpacity() is 0;
			}
			instances.RemoveAll(x =>x.disposed);

			container.SetActive(container.childCount > 0);
		}

		public void Popup(string content, float duration = 3)
		{
			var visualElement = (container.Create<VisualElement>(popupTemplate.CloneTree));
				
			instances.Add(new ViewModel()
			{
				visualElement = visualElement,
				exitTime = Time.time + duration
			});
		}
	}
}