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

/// <summary>
/// A simple class that can create multiple objectpools
/// </summary>
public class ObjectPool : Singleton<ObjectPool>
{
    // Class that holds a objectPool
    [Serializable]
    public class ActiveAndInActive
    {
        public List<GameObject> Active = new List<GameObject>();
        public Queue<GameObject> InActive = new Queue<GameObject>();
        public GameObject Holder;
    }

    // Holds all the objectpools. every object pool has a tag 
    public Dictionary<string, ActiveAndInActive> ObjectPoolDic = new Dictionary<string, ActiveAndInActive>();

    // The main function that Spawns A Prefab with a string as tag to 
    public GameObject SpawnPrefab(string poolTag, GameObject prefab, Vector3 spawnLocation)
    {
        // Creates a new objectpool if it doesn't exists
        if (!ObjectPoolDic.ContainsKey(poolTag))
        {
            ObjectPoolDic[poolTag] = new ActiveAndInActive();
            ObjectPoolDic[poolTag].Holder = new GameObject($"{poolTag}s");
        }

        // If we don't have any InActive objects we spawn a new one
        if (ObjectPoolDic[poolTag].InActive.Count == 0)
        {
            var newPrefab = Instantiate(prefab, spawnLocation, Quaternion.identity);
            newPrefab.transform.parent = ObjectPoolDic[poolTag].Holder.transform;
            ObjectPoolDic[poolTag].Active.Add(newPrefab);
            return newPrefab;
        }
        // If we do have a InActive object we spawn it in
        else
        {
            var OldPrefab = ObjectPoolDic[poolTag].InActive.Dequeue();
            ObjectPoolDic[poolTag].Active.Add(OldPrefab);
            OldPrefab.SetActive(true);
            OldPrefab.transform.position = spawnLocation;
            return OldPrefab;
        }
    }

    public GameObject deActivedPrefab(string poolTag, GameObject sceneobject)
    {
        // Check if there was a ObjectPool with this tag
        if (!ObjectPoolDic.ContainsKey(poolTag))
        {
            Debug.LogError("prefab was never spawned");
            return null;
        }

        // Checks if the object exists in the pool
        if(!ObjectPoolDic[poolTag].Active.Contains(sceneobject)) return null;
        
        // Put it back in the queue and deActive it
        ObjectPoolDic[poolTag].Active.Remove(sceneobject);
        ObjectPoolDic[poolTag].InActive.Enqueue(sceneobject);
        sceneobject.SetActive(false);
        
        return sceneobject;
    }
}