using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ObjectPoolManager : MonoBehaviour
{
    public static ObjectPoolManager Instance { get; private set; }

    // 多个对象池，每种类型一个 Queue
    private Dictionary<string, Queue<GameObject>> poolDict = new Dictionary<string, Queue<GameObject>>();

    // 记录每种类型的原始 prefab
    // private Dictionary<string, GameObject> prefabDict = new Dictionary<string, GameObject>();

    private void Awake()
    {
        if (Instance == null) Instance = this;
        else Destroy(gameObject);

        DontDestroyOnLoad(gameObject); // 保持池子跨场景有效
    }

    /// <summary>
    /// 获取一个对象（从对象池中或新建）
    /// </summary>
    public GameObject Get(string key, GameObject prefab, Transform parent = null)
    {
        if (!poolDict.ContainsKey(key))
        {
            poolDict[key] = new Queue<GameObject>();
            // prefabDict[key] = prefab;
        }

        GameObject obj;

        if (poolDict[key].Count > 0)
        {
            obj = poolDict[key].Dequeue();
        }
        else
        {
            // obj = Instantiate(prefabDict[key]);
            obj = Instantiate(prefab);
        }

        obj.SetActive(true);
        if (parent != null)
            obj.transform.SetParent(parent);

        return obj;
    }

    /// <summary>
    /// 回收一个对象（回到池中）
    /// </summary>
    public void Release(string key, GameObject obj)
    {
        if (!poolDict.ContainsKey(key))
        {
            Debug.LogWarning("ObjectPoolManager: 没有这个 key 的对象池：" + key);
            Destroy(obj); return;
        }

        obj.SetActive(false);
        obj.transform.SetParent(transform); // 可统一收纳到 manager 下
        poolDict[key].Enqueue(obj);
    }

    /// <summary>
    /// 清除所有池（可用于重启/清场）
    /// </summary>
    public void ClearAllPools()
    {
        foreach (var queue in poolDict.Values)
        {
            while (queue.Count > 0)
            {
                GameObject obj = queue.Dequeue();
                Destroy(obj);
            }
        }

        poolDict.Clear();
        // prefabDict.Clear();
    }
}