using System.Collections;
using System.Collections.Generic;
using UnityEngine;
/*******************************************************************************
*Create By CG
*Function 对象池管理_大池子
*******************************************************************************/
namespace ZXK.Framework
{
    public class ObjectPoolsManager : ClassSingleton<ObjectPoolsManager>
    {
        //所有对象池的父物体
        private GameObject _poolsParent;
        //所有对象池的共同父物体在Hierarchy窗口的名字
        private const string _poolsParentName = "ObjectPools";

        //当前所有对象池的列表
        private List<ObjectPool> _objectPoolsList = new List<ObjectPool>();

        //用来表示游戏对象所属的对象池
        private Dictionary<GameObject, ObjectPool> _objectsDictionary = new Dictionary<GameObject, ObjectPool>();

        /// <summary>
        /// 从对象池生成游戏对象。
        /// 如果对象池有，从对象池中取出来用。
        /// 如果对象池没有，实例化该对象。
        /// </summary>
        public GameObject Spawn(GameObject prefab, Vector3 position, Quaternion rotation, Transform parent = null)
        {
            if (prefab == null) return null;

            //如果场景中没有对象池的父物体，则生成一个空物体，作为所有对象池的父物体
            CreatePoolsParentIfNull();

            //先通过预制体来查找它所属的小对象池，如果找到了，则返回这个小对象池。
            //如果找不到，则创建一个小对象池，用来存放这种预制体。
            ObjectPool objectPool = FindPoolByPrefabOrCreatePool(prefab);

            GameObject go = objectPool.Spawn(position, rotation, parent);

            _objectsDictionary.Add(go, objectPool);

            return go;
        }

        public void Despawn(GameObject go, float delayTime = 0)
        {
            if (go == null) return;
            MonoManager.Instance.StartCoroutine(DespawnCoroutine(go, delayTime));
        }
        IEnumerator DespawnCoroutine(GameObject go, float delayTime = 0)
        {
            //等待指定秒数
            if (delayTime > 0)
                yield return new WaitForSeconds(delayTime);

            if (_objectsDictionary.TryGetValue(go, out ObjectPool pool))
            {
                _objectsDictionary.Remove(go);

                pool.Despawn(go);
            }
            else
            {
                //获取这个游戏对象所属的对象池
                pool = FindPoolByUsedGameObject(go);

                if (pool != null)
                {
                    pool.Despawn(go);
                }
            }
        }

        ObjectPool FindPoolByUsedGameObject(GameObject go)
        {
            if (go == null) return null;

            for (int i = 0; i < _objectPoolsList.Count; i++)
            {
                ObjectPool pool = _objectPoolsList[i];

                for (int j = 0; j < pool._UsedGameObjectList.Count; j++)
                {
                    if (pool._UsedGameObjectList[j] == go)
                        return pool;
                }
            }

            return null;
        }

        //先通过预制体来查找它所属的小对象池，如果找到了，则返回这个小对象池。
        //如果找不到，则创建一个小对象池，用来存放这种预制体。
        private ObjectPool FindPoolByPrefabOrCreatePool(GameObject prefab)
        {
            //确保大对象池是存在的
            CreatePoolsParentIfNull();

            //查找并返回该预制体对数的对象池
            ObjectPool objectPool = null;
            if (prefab != null)
            {
                for (int i = 0; i < _objectPoolsList.Count; i++)
                {
                    if (_objectPoolsList[i]._Prefab == prefab)
                        objectPool = _objectPoolsList[i];
                }
            }
            if (objectPool == null)
            {
                objectPool = new GameObject($"ObjectPool_{prefab.name}").AddComponent<ObjectPool>();

                objectPool._Prefab = prefab;

                objectPool.transform.SetParent(_poolsParent.transform);

                _objectPoolsList.Add(objectPool);
            }

            return objectPool;
        }

        //如果场景中没有对象池的父物体，则生成一个空物体，作为所有对象池的父物体。
        private void CreatePoolsParentIfNull()
        {
            if (_poolsParent == null)
            {
                _objectPoolsList.Clear();
                _objectsDictionary.Clear();

                _poolsParent = new GameObject(_poolsParentName);
            }
        }       
    }
}