using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using BITKit.UX;
using UnityEngine;
using Cysharp.Threading.Tasks;
using kcp2k;
using UnityEngine.Pool;
using UnityEngine.UIElements;
namespace BITKit
{
    [CustomType(typeof(IUXWaiting))]
    public class UXWaiting : MonoBehaviour,IUXWaiting
    {
        public sealed class WaitingHandle : IUXWaitingHandle
        {
            public string Message
            {
                get => label.text;
                set => SetMessage(value);
            }
            public object Container => container;
            internal VisualElement container;
            internal Label label;
            public async void SetMessage(string message)
            {
                await UniTask.SwitchToMainThread();
                if(container.panel!=null)
                {
                    label.text = message;
                }
                else
                {
                    BIT4Log.Log<UXWaiting>("WaitingHandle is destroyed");
                }
            }
        }
        
        [SerializeField] private VisualTreeAsset handleTemplate;
        [SerializeField] private bool asGlobal;
        
        [UXBindPath("waiting-container")]
        private VisualElement _container;
        [UXBindPath("waiting-root")]
        private VisualElement _root;

        private Pool<IUXWaitingHandle> _pool;
        private readonly HashSet<IUXWaitingHandle> _handles = new();

        public IUXWaitingHandle Get()
        {
            var handle = _pool.Take();
            Active();
            _handles.Add(handle);
            return handle;
            async void Active()
            {
                await UniTask.SwitchToMainThread();
                handle.As<WaitingHandle>().container.SetActive(true);
                _root.SetActive(true);
            }
        } 
        public async void Release(IUXWaitingHandle handle)
        {
            await UniTask.SwitchToMainThread();
            if (destroyCancellationToken.IsCancellationRequested) return;
            _pool.Return(handle);
            _handles.Remove(handle);
            Check();
        }
        private void Awake()
        {
            UXUtils.Inject(this);
            _container.Clear();
            _pool = new Pool<IUXWaitingHandle>(Create,OnReset,10);
            if (asGlobal)
            {
                DI.Register<IUXWaiting>(this);
            }
            _root.SetActive(false);
        }

        private void Start()
        {
            Check();
        }

        private async void OnReset(IUXWaitingHandle obj)
        {
            await UniTask.SwitchToMainThread();
            obj.As<WaitingHandle>().container.SetActive(false);
        }
        [BIT]
        private async void Check()
        {
            await UniTask.Yield();
            await UniTask.SwitchToMainThread();
            if(destroyCancellationToken.IsCancellationRequested) return;
            _root.SetActive(_handles.Count>0);
        }
        private IUXWaitingHandle Create()
        {
            var handle = new WaitingHandle
            {
                container = _container.Create(handleTemplate),
                label = _container.Q<Label>(UXConstant.ContextLabel)
            };

            handle.SetMessage($"未初始化");
            
            handle.container.SetActive(false);
            
            return handle;
        }
    }
}