using UnityEngine;
using System;
using System.Collections;

/// <summary>
/// 오브젝트를 관리하는 클래스 (오브젝트 풀)
/// </summary>
public class ObjectManager : MonoBehaviour {

	public static ObjectManager Instance 
	{ 
		get; 
		private set; 
	}
	
	#region member
	/// <summary>	
	/// 프리팹을 오브젝트 풀에 등록 한다 
	/// </summary>	
	[Serializable]	
	public class ObjectPoolEntry {		
		/// <summary>		
		/// 인스턴스를 생성하기 위한 프리팹 	
		/// </summary>		
		[SerializeField]		
		public GameObject Prefab;
		
		/// <summary>	
		/// 생성되는 프리팹 갯수 	
		/// </summary>		
		[SerializeField]		
		public int Count;
		
		[HideInInspector]		
		public GameObject[] pool;
		
		[HideInInspector]		
		public int objectsInPool = 0;	
	}	
	#endregion
	
	/// <summary>
	/// 지정한 양 만큼 처리 하도록 버퍼를 생성
	/// </summary>	
	public ObjectPoolEntry[] Entries;
	
	/// <summary>	
	/// 사용되지 않고 있는 풀링된 객체를 관리 하는 컨테이너
	/// </summary>	
	protected GameObject ContainerObject;
	
	void OnEnable()		
	{	
		Instance = this;		
	}
	
	// Use this for initialization	
	void Start()		
	{	
		ContainerObject = new GameObject("ObjectPool");
		
		// 프리랩을 반복하여 새로운 목록을 확인	
		for (int i = 0; i < Entries.Length; i++)		
		{	
			ObjectPoolEntry objectPrefab = Entries[i];
			
			// 임시 저장될 오브젝트를 생성	
			objectPrefab.pool = new GameObject[objectPrefab.Count];
			
			// 임시 저장될 오브젝트에 프리랩들을 채운다                   			
			for (int n = 0; n < objectPrefab.Count; n++)		
			{	
				GameObject newObj = (GameObject)Instantiate(objectPrefab.Prefab);
				newObj.name = objectPrefab.Prefab.name; 	
				PoolObject(newObj);	
			}	
		}	
	}
	
	/// <summary>
	/// 스트링으로 풀링된 객체를 가져온다 
	/// </summary>	
	/// <returns>	
	/// 스트링으로 찾은 객체	
	/// </returns>	
	/// <param name='objectType'>	
	/// 가져올 객체
	/// </param>
	/// <param name='onlyPooled'>
	/// true 면 객체가 풀링 되어있으면 반환한다.
	/// </param>
	public GameObject GetObjectForType(string objectType, Vector3 pos, Quaternion rot, bool onlyPooled = true)		
	{
		for (int i = 0; i < Entries.Length; i++)		
		{	
			GameObject prefab = Entries[i].Prefab;
			
			if (prefab.name != objectType)			
				continue;
			
			if (Entries[i].objectsInPool > 0)				
			{		
				GameObject pooledObject = Entries[i].pool[--Entries[i].objectsInPool]; 			
				pooledObject.transform.parent = null;
				pooledObject.transform.position = pos;
				pooledObject.transform.rotation = rot;
				pooledObject.SetActive(true);	
				return pooledObject;
				
			} 
			else if (!onlyPooled)			
			{	
				GameObject obj = (GameObject)Instantiate(Entries[i].Prefab);
				obj.name = obj.name + "_not_pooled";	
				return obj;
			}
		}
		
		return null;	
	}

	/// <summary>
	/// 스트링으로 풀링된 객체를 가져온다 
	/// then null will be returned.	
	/// </summary>	
	/// <returns>	
	/// 스트링으로 찾은 객체	
	/// </returns>	
	/// <param name='objectType'>	
	/// 가져올 객체
	/// </param>
	/// <param name='onlyPooled'>
	/// true 면 객체가 풀링 되어있으면 반환한다.
	/// </param>
	
	public GameObject GetObjectForType(string objectType, Vector2 pos, bool onlyPooled = true)		
	{
		for (int i = 0; i < Entries.Length; i++)		
		{	
			GameObject prefab = Entries[i].Prefab;
			
			if (prefab.name != objectType)			
				continue;
			
			if (Entries[i].objectsInPool > 0)				
			{		
				GameObject pooledObject = Entries[i].pool[--Entries[i].objectsInPool]; 			
				pooledObject.transform.parent = null;
				pooledObject.transform.position = pos;
				pooledObject.SetActive(true);	
				return pooledObject;
				
			} 
			else if (!onlyPooled)			
			{	
				GameObject obj = (GameObject)Instantiate(Entries[i].Prefab);
				obj.name = obj.name + "_not_pooled";	
				return obj;
			}
		}
		
		return null;	
	}
	
	/// <summary>	
	/// 객체를 다시 풀링 한다
	/// </summary>	
	/// <param name='obj'>	
	/// 풀링할 객체	
	/// </param>	
	public void PoolObject(GameObject obj)		
	{
		for (int i = 0; i < Entries.Length; i++)		
		{
			if (Entries[i].Prefab.name != obj.name)				
				continue;
			
			obj.SetActive(false); 			
			obj.transform.parent = ContainerObject.transform;			
			if (obj.rigidbody != null) 
			{	
				obj.rigidbody.velocity = Vector3.zero;	
			}
			
			Entries[i].pool[Entries[i].objectsInPool++] = obj;
			
			return;	
		}
		Destroy(obj);	
	}
}