using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using Quadtree;
using Quadtree.Items;
using UnityEngine;
using UnityEngine.Pool;

namespace BITKit.OpenWorld
{
	
	[Serializable]
	public struct UnityWorldChunkSingleton:IChunkService
	{
		public void Register(IWorldChunkObject obj)=>UnityWorldChunkService.Register(obj);

		public void Unregister(IWorldChunkObject obj)=>UnityWorldChunkService.Unregister(obj);
	}
	public class UnityWorldChunkService : MonoBehaviour
	{
		[RuntimeInitializeOnLoadMethod]
		private static void Reload()
		{
			_registerQueue.Clear();
			_unregisterQueue.Clear();
		}
		private static readonly ConcurrentQueue<IWorldChunkObject> _registerQueue = new();
		private static readonly ConcurrentQueue<IWorldChunkObject> _unregisterQueue = new();
		public static void Register(IWorldChunkObject obj)=>_registerQueue.Enqueue(obj);
		public static void Unregister(IWorldChunkObject obj)=>_unregisterQueue.Enqueue(obj);
		private QuadtreeRoot<IWorldChunkObject, Node<IWorldChunkObject>> _quadtree;

		[SerializeReference, SubclassSelector] private ITicker ticker;
		[SerializeField,ReadOnly] private int count;
		[SerializeField,Range(0,128)] private int[] lodDistances;
		[SerializeField] private Vector3 size;
        private Camera _camera;
        private readonly HashSet<int> cacheList = new();
		private void Start()
		{
			ticker.Add(OnTick);
			destroyCancellationToken.Register(Dispose);
			_quadtree = new QuadtreeRoot<IWorldChunkObject, Node<IWorldChunkObject>>(default,size);
			_camera = Camera.main;
		}
		private void Dispose()
		{
			ticker.Remove(OnTick);
			Reload();
		}
		private void OnTick(float deltaTime)
		{
			while (_unregisterQueue.TryDequeue(out var obj))
			{
				_quadtree.Remove(obj);
			}
			while (_registerQueue.TryDequeue(out var obj))
			{
				obj.Id = count++;
				_quadtree.Insert(obj);
			}
			
			var cameraPosition = _camera.transform.position;

			
			for (var index = 0; index < lodDistances.Length; index++)
			{
				var distance = lodDistances[index];
				foreach (var chunkObject in _quadtree.Find(new Bounds(cameraPosition, Vector3.one * distance)))
				{
					if (cacheList.Contains(chunkObject.Id)) continue;
					cacheList.Add(chunkObject.Id);
					var lod = chunkObject.Lod;
					if (lod == index) continue;
					chunkObject.Lod = index;
				}
			}
			
			cacheList.Clear();
		}

		private void OnDrawGizmosSelected()
		{
			var pos = transform.position;
			// pos.x-=size.x/2;
			// pos.y-=size.y/2;
			// pos.z-=size.z/2;
			Gizmos.DrawWireCube(pos, size);
			
			
		}
	}
}