// ***********************************************************************
// Assembly         : Unity
// Author           : Kimch
// Created          : 
//
// Last Modified By : Kimch
// Last Modified On : 
// ***********************************************************************
// <copyright file= "KUIList" company=""></copyright>
// <summary></summary>
// ***********************************************************************
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// KUIItem 对象管理(简单)
/// </summary>
public class KUIList : MonoBehaviour
{
	#region Field

	/// <summary>
	/// 物品模版
	/// </summary>
	public GameObject itemTemplate;
	/// <summary>
	/// 物品列表
	/// </summary>
	private readonly List<GameObject> _itemObjects = new List<GameObject>();

	#endregion

	#region Property

	/// <summary>
	/// 
	/// </summary>
	public int count
	{
		get { return _itemObjects.Count; }
	}

	#endregion

	#region Method

	/// <summary>
	/// 添加模板
	/// </summary>
	/// <typeparam name="T"></typeparam>
	public T AddTemplate<T>(bool useTemplate = false) where T : KUIWidget
	{
		if (!itemTemplate && transform.childCount > 0)
		{
			itemTemplate = transform.GetChild(0).gameObject;
		}
		T result = default;

		if (itemTemplate)
		{
			itemTemplate.SetActive(false);
			result = itemTemplate.GetComponent<T>();
			if (!result)
				result = itemTemplate.AddComponent<T>();
		}

		if (useTemplate)
		{
			for (int i = 0; i < transform.childCount; i++)
			{
				var child = transform.GetChild(i);
				if (child.GetComponent<T>())
				{
					child.gameObject.SetActive(false);
					_itemObjects.Add(child.gameObject);
				}
			}
		}
		return result;
	}

	public void PreCreate(int count)
	{
		if (itemTemplate)
		{
			for (int i = 0; i < count; i++)
			{
				var itemGO = Instantiate(itemTemplate, this.transform);
				_itemObjects.Add(itemGO);
			}
		}
	}

	/// <summary>
	/// 
	/// </summary>
	/// <param name="active">默认活跃</param>
	/// <returns></returns>
	private KUIWidget AddObject(bool active = true)
	{
		if (itemTemplate)
		{
			var itemGO = Instantiate(itemTemplate, this.transform);
			itemGO.SetActive(active);
			_itemObjects.Add(itemGO);
			itemGO.name = itemTemplate.name + "_" + _itemObjects.Count;

			var item = itemGO.GetComponent<KUIWidget>();
			if (item)
			{
				item.index = _itemObjects.Count - 1;
				return item;
			}
		}
		return null;
	}

	/// <summary>
	/// 
	/// </summary>
	/// <param name="amount"></param>
	private void ActivateAvailableObjects(int amount)
	{
		if (_itemObjects.Count < amount)
		{
			amount = _itemObjects.Count;
		}

		for (int i = 0; i < amount; i++)
		{
			_itemObjects[i].SetActive(true);
		}

		for (int i = _itemObjects.Count - 1; i >= amount; i--)
		{
			_itemObjects[i].SetActive(false);
		}
	}

	/// <summary>
	/// 
	/// </summary>
	/// <param name="amount"></param>
	public void Clear(int amount = 0)
	{
		this.ActivateAvailableObjects((amount <= _itemObjects.Count) ? amount : _itemObjects.Count);
	}

	/// <summary>
	/// 
	/// </summary>
	/// <returns></returns>
	public KUIWidget GetItem()
	{
		var item = _itemObjects.Find(obj => !obj.activeSelf);
		if (item)
		{
			item.SetActive(true);
			return item.GetComponent<KUIWidget>();
		}
		else
		{
			return AddObject(true);
		}
	}

	/// <summary>
	/// 
	/// </summary>
	/// <typeparam name="T"></typeparam>
	/// <returns></returns>
	public T GetItem<T>() where T : KUIWidget
	{
		var item = _itemObjects.Find(obj => !obj.activeSelf);
		if (item)
		{
			item.SetActive(true);
			return item.GetComponent<T>();
		}
		else
		{
			return (T)AddObject(true);
		}
	}

	/// <summary>
	/// 
	/// </summary>
	/// <param name="index"></param>
	/// <returns></returns>
	public KUIWidget GetItem(int index)
	{
		if (index < _itemObjects.Count)
		{
			var itemObject = _itemObjects[index];
			return itemObject.GetComponent<KUIWidget>();
		}
		return this.AddObject(true);
	}

	/// <summary>
	/// 
	/// </summary>
	/// <param name="index"></param>
	/// <param name="active"></param>
	/// <returns></returns>
	public KUIWidget GetItem(int index, bool active)
	{
		if (index < _itemObjects.Count)
		{
			var itemObject = _itemObjects[index];
			itemObject.SetActive(active);
			return itemObject.GetComponent<KUIWidget>();
		}
		return this.AddObject(active);
	}

	/// <summary>
	/// 
	/// </summary>
	/// <param name="amount"></param>
	public void RefreshList(int amount)
	{
		ActivateAvailableObjects(amount);
	}

	#endregion

	#region Unity

	private void Awake()
	{
		//if (!itemTemplate)
		//{
		//	if (transform.childCount > 0)
		//		itemTemplate = transform.GetChild(0).gameObject;
		//}

		//if (itemTemplate)
		//{
		//	itemTemplate.SetActive(false);
		//}
	}

	#endregion

	#region Layout

	private void InitLayout()
	{

	}

	#endregion
}