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

/// <summary>prefab缓存池</summary>
public class PrefabManager : MonoBehaviour
{

	#region 单利函数
	private static PrefabManager _instance = null;

	public int RevertCt = 0;
	public static PrefabManager Instance
	{
		get
		{
			if (_instance == null) {
				GameObject go = new GameObject ();
				go.name = "PrefabManager";
				DontDestroyOnLoad (go);
				_instance = go.AddComponent<PrefabManager> ();
			}

			return _instance;
		}
	}

	void Awake()
	{
		_instance = this;
	}

	#endregion

	/// <summary>缓存列表</summary>
	private Dictionary<string, PrefabInfo> mDictPrefab = new Dictionary<string, PrefabInfo> ();

	public int GetPrefabCt(string assetsName, UnityEngine.Object assetsObject)
	{
		PrefabInfo prefabInfo = GetPrefabInfo(assetsName, assetsObject);
		return prefabInfo.Ct;
	}



	/// <summary>得到一个组件</summary>
	public GameObject GetPrefab(string assetsName, UnityEngine.Object assetsObject)
	{
		PrefabInfo prefabInfo = GetPrefabInfo(assetsName, assetsObject);
		return prefabInfo.GetPrefab();
	}

	/// <summary>删除全部</summary>
	public void RemoveAllPrefab()
	{
		foreach (PrefabInfo info in mDictPrefab.Values) 
		{
			info.Dispose ();
		}
		mDictPrefab.Clear ();
	}

	/// <summary>删除一组资源</summary>
	public void RemovePrefab(string assetsName)
	{
		PrefabInfo prefabInfo = GetPrefabInfo(assetsName);
		if (prefabInfo != null) 
		{
			mDictPrefab.Remove (prefabInfo.PrefabKey);
			prefabInfo.Dispose ();
		}
	}

	/// <summary>恢复一个GameObject的缓存状态</summary>
	public void RevertPrefab(GameObject prefabGO, string assetsName, UnityEngine.Object assetsObject = null)
	{
		//CDebug.Log ("RevertPrefab " +  prefabGO.name + " "  +  assetsName);
		PrefabInfo prefabInfo = GetPrefabInfo(assetsName, assetsObject);
		if (prefabInfo == null) {
			//CDebug.Log ("RevertPrefab " + prefabGO.name + " is NULL");
		} else {
			//CDebug.Log ("RevertPrefab " + prefabInfo.Ct);
		}
		prefabInfo.RevertPrefab(prefabGO);
		RevertCt++;
	}

	/// <summary>获得PrefabInfo</summary>
	private PrefabInfo GetPrefabInfo(string assetsName, UnityEngine.Object assetsObject = null)
	{
		string assetsKey = PrefabInfo.AssetsToKey (assetsName);
		PrefabInfo prefabInfo = null;
		if (mDictPrefab.ContainsKey (assetsKey))
		{
			prefabInfo = mDictPrefab [assetsKey];
		}
		else
		{
			if (assetsObject != null) 
			{
				prefabInfo = new PrefabInfo (assetsName, assetsObject);
				mDictPrefab.Add (assetsKey, prefabInfo);
			}
		}
		return prefabInfo;
	}
}

/// <summary>内存中的组件对象</summary>
public class PrefabInfo
{

	/// <summary>资源源对象</summary>
	public UnityEngine.Object mResourceObject = null;
	/// <summary>资源包名称</summary>
	public string mAssetsName = string.Empty;
	/// <summary>资源Key值</summary>
	private string mPrefabKey = string.Empty;

	/// <summary>缓存的GameObject列表</summary>
	private List<GameObject> mCatchObject = new List<GameObject> ();

	/// <summary>构造函数</summary>
	public PrefabInfo(string assetsName, UnityEngine.Object assetsObject = null)
	{
		mAssetsName = assetsName;

		if (assetsObject == null)
		{
			CDebug.LogError ("缓存了错误的资源:" + PrefabKey);
		}
		else
		{
			mResourceObject = assetsObject;
		}
	}

	/// <summary>释放函数</summary>
	public void Dispose()
	{
		for (int i = 0; i < mCatchObject.Count; i++) 
		{
			GameObject.Destroy (mCatchObject[i]);
		}
		mCatchObject.Clear ();
		mResourceObject = null;
	}

	/// <summary>得到资源</summary>
	public GameObject GetPrefab()
	{
		int catchIndex = GetIndex(mCatchObject, false);
		GameObject returnObj = (catchIndex != -1) ? mCatchObject [catchIndex] : null;

		//存在已经创建的对象
		if (returnObj != null) 
		{
			mCatchObject [catchIndex] = null;
		}
		//创建一个新的
		else 
		{
			if (mResourceObject != null) 
			{
				returnObj = (GameObject)GameObject.Instantiate (mResourceObject);
				returnObj.transform.position = Vector3.zero;
				returnObj.transform.localScale = Vector3.one;
				returnObj.transform.rotation = Quaternion.Euler (Vector3.zero);
				//CDebug.Log ("Create : " + returnObj.name);
			}
			else
			{
				CDebug.LogError ("缓存池创建资源错误:" + mAssetsName);
			}

			if (CStaticMethod.IsEditor) 
			{
				returnObj.name = PrefabKey;
			}

			returnObj.SetActive (false);
		}
		return returnObj;
	}

	/// <summary>恢复一个GameObject的缓存状态</summary>
	public void RevertPrefab(GameObject prefabGO)
	{
		int nullIndex = GetIndex(mCatchObject, true);
		if (nullIndex != -1)
		{
			mCatchObject [nullIndex] = prefabGO;
		}
		else 
		{
			mCatchObject.Add (prefabGO);
		}
		prefabGO.transform.position = Vector3.zero;
		prefabGO.SetActive (false);
	}

	/// <summary>得到索引, 非空位置或null位置</summary>
	private int GetIndex(List<GameObject> list, bool isGetNull = true)
	{
		int catchCount = list.Count;
		for (int i = 0; i < catchCount; i++)
		{
			if ((list [i] != null && !isGetNull) || (list [i] == null && isGetNull)) 
			{
				return i;
			}
		}
		return -1;
	}

	/// <summary>资源Key值</summary>
	public string PrefabKey
	{
		get 
		{
			if (mPrefabKey == string.Empty)
			{
				mPrefabKey = AssetsToKey (mAssetsName);
			}
			return mPrefabKey;
		}
	}

	/// <summary>转换资源Key值</summary>
	public static string AssetsToKey(string assetsName)
	{
		return assetsName;
		/*
		StringBuilder stringBuilder = new StringBuilder ();
		stringBuilder.Append (assetsName);
		stringBuilder.Append ("_");
		return stringBuilder.ToString ();*/
	}

	public int Ct
	{
		get{ return mCatchObject.Count;}
	}
}