using System.Collections.Generic;
using UnityEngine;

namespace Main
{
    /// <summary>
    /// 类对象池
    /// </summary>
    public interface IClassPool
    {
        /// <summary>
        /// 将类对象存进池里
        /// </summary>
        /// <param name="obj"></param>
        void Creation(GameObject obj);
        /// <summary>
        /// 从未激活池里面取类对象，并放入激活池
        /// </summary>
        /// <returns></returns>
        GameObject Spawn(Transform parent);
        /// <summary>
        /// 从激活池中释放类对象到未激活池中
        /// </summary>
        GameObject RecycleSpawn(GameObject obj);
        /// <summary>
        /// 回收类对象
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
    
        /// <summary>
        /// 清空类对象池
        /// </summary>
        void RecycleAll();
        
        int GetPolLength();
    }
    public class GameObjectPool:IClassPool
    {
        private GameObject poolObject;
        
        /// <summary>
        /// 回收对象的父物体
        /// </summary>
        private Transform recycle;
        
        protected List<GameObject> activepool = new List<GameObject>();
        protected Stack<GameObject> inactivepool = new Stack<GameObject>();
        //没有回收的个数
        protected int noRecycleCount;

        public GameObjectPool(GameObject poolObject,Transform recycle)
        {
            this.poolObject = poolObject;
            this.recycle = recycle;
        }
        /// <summary>
        /// 将类对象存进池里
        /// </summary>
        /// <param name="obj"></param>
        public void Creation(GameObject obj)
        {
            inactivepool.Push(obj);
            noRecycleCount++;
        }



        /// <summary>
        /// 从未激活池里面取类对象，并放入激活池
        /// </summary>
        /// <param name="createIfPoolEmpty">如果为空是否new出来</param>
        public GameObject Spawn(Transform parent)
        {
            GameObject obj = null;
            if(noRecycleCount>0)
            {
                obj = inactivepool.Pop();
                obj.transform.SetParent(parent);
                noRecycleCount--;
                if(obj==null)
                    Debug.LogErrorFormat("对象池中不存在此对象【{0}】请排查代码", obj);
            }
            else
            {
                obj= GameObject.Instantiate(poolObject,parent);
            }
            obj.transform.localPosition = Vector3.zero;
            obj.transform.localRotation = Quaternion.identity;
            obj.transform.localScale = Vector3.one;
            obj.SetActive(true);
            activepool.Add(obj);
            
            return obj;
        }
        /// <summary>
        /// 从激活池中释放类对象到未激活池中
        /// </summary>
        public GameObject RecycleSpawn(GameObject obj)
        {
            if(obj!=null&&activepool.Contains(obj))
            {
                activepool.Remove(obj);
                inactivepool.Push(obj);
                obj.transform.parent = recycle;
                obj.gameObject.SetActive(false);
                noRecycleCount++;
            }
            return null;
        }
    
        /// <summary>
        /// 清空类对象池
        /// </summary>
        public void RecycleAll()
        {
            noRecycleCount=0;
          
            foreach (var pool in inactivepool)
            {
                GameObject.Destroy(pool);
            }
            inactivepool.Clear();
            foreach (var pool in activepool)
            {
                GameObject.Destroy(pool);
            }
            activepool.Clear();
        }
        public int GetPolLength()
        {
            return inactivepool.Count;
        }
    }
}