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

namespace XericLibrary.Runtime.MacroLibrary
{
	public static class MacroObject
	{
		#region 对象操作


		/// <summary>
		/// 获取一个变换节点下所有的子成员
		/// </summary>
		/// <param name="trans"></param>
		/// <returns></returns>
		public static IEnumerable<Transform> GetChildren(this Transform trans)
		{
			for(int i = 0; i < trans.childCount; i++)
			{
				yield return trans.GetChild(i);
			}
		}

		/// <summary>
		/// 在所有子成员中深度优先找到第一个组件
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="trans"></param>
		/// <param name="recursion">遍历深度，0表示仅在此处寻找，1表示在包含下一级在内的所有成员中寻找</param>
		/// <returns></returns>
		public static IEnumerable<T> GetChildrenRecursionComponents<T>(this Transform trans, int recursion = 1)
		where T : Component
		{
			int newRecursion = recursion - 1;
			
			foreach(var item in trans.GetChildren())
			{
				var comp = item.GetComponent<T>();
				if(comp == null && newRecursion > 0)
					comp = item.GetChildrenRecursionComponent<T>(newRecursion);
				yield return comp;
			}
		}

		/// <summary>
		/// 按深度优先寻找一个组件
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="trans"></param>
		/// <param name="depth">遍历深度，0表示仅在第一子集中寻找，1表示在包含下一级在内的所有成员中寻找</param>
		/// <returns></returns>
		public static T GetChildrenRecursionComponent<T>(this Transform trans, int depth = 1)
		where T : Component
		{
			T result;
			int newDepth = depth - 1;

#if true   // 如果不知道这里在找什么的可以打开调试看看                           
			foreach(var item in trans.GetChildren())
			{
				result = item.GetComponent<T>();
				if(result == null && newDepth > 0)
					result = item.GetChildrenRecursionComponent<T>(newDepth);
				if(result != null)
					return result;
			}
#else
			string info = $"{depth}.   开始在{trans.name}中寻找\r\n";
			foreach(var item in trans.GetChildren())
			{
				info += $"{depth}. > 正在{item.name}中寻找\r\n";

				result = item.GetComponent<T>();

				info += $"{depth}.   当前节点{(result == null ? "不包含组件":"包含组件")}\r\n";

				if(result == null && newDepth >= 0)
				{
					info += $"{depth}.   前往深层寻找 > \r\n";
					result = item.GetRecursionComponent<T>(newDepth);
					info += $"{depth}.   深层查找返回 < \r\n";
				}

				if(result != null)
				{
					info += $"{depth}.   已找到结果：{result.name} \r\n";
					Debug.Log(info);
					return result;
				}
				info += $"{depth}.   没有找到任何东西 \r\n";
			}
			Debug.Log(info + "没有找到，空结束");
#endif
			return null;
		}

		/// <summary>
		/// 无论如何都要获取一个组件
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <returns></returns>
		public static T GetComponentAnyway<T>(this GameObject obj)
		where T : Component
		{
			var component = obj.GetComponent<T>();
			if(component is null)
				component = obj.AddComponent<T>();
			return component;
		}

		/// <summary>
		/// 无论如何都要获取一个对象
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="obj"></param>
		/// <returns></returns>
		public static T GetObjectAnyway<T>(this T obj)
		where T : new()
		{
			if(obj is null)
				obj = new T();
			return obj;
		}

		#endregion

	}
}