using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

using UnityEngine;

using XericLibrary.Runtime.Type;

namespace XericLibrary.Runtime.Security
{
    /// <summary>
    /// 程序流程保全
    /// </summary>
    public class ProgramFlowSecurityExtend : WeaklyObject
    {
		#region 字段属性

		/// <summary>
		/// 可扩展事件
		/// </summary>
		public event Action ExtensibleDelegation
		{
			add
			{
				if(!DelegateContains(value))
					DelegateAdd(value);
			}
			remove
			{
				DelegateRemove(value);
			}
		}

		/// <summary>
		/// 事件列表
		/// </summary>
		private List<DelegateExtensibleFlag> delegateList;

		#endregion

		#region 类内类

		/// <summary>
		/// 事件扩展标识
		/// </summary>
		public class DelegateExtensibleFlag
		{
			/// <summary>
			/// 事件
			/// </summary>
			public Action Event;
			/// <summary>
			/// 单步执行
			/// </summary>
			public bool Doonce;
			/// <summary>
			/// 调用保护
			/// </summary>
			public bool Conservate;

			public DelegateExtensibleFlag(Action action, bool doonce = false)
			{
				this.Event = action;
				this.Doonce = doonce;
				this.Conservate = false;
			}

			public override bool Equals(object obj)
			{
				if(obj is DelegateExtensibleFlag def)
					return def.Event == this.Event;

				return false;
			}

			public override int GetHashCode()
			{
				return Event.GetHashCode();
			}
		}

		public DelegateExtensibleFlag DelegateFind(Action action)
		{
			return delegateList
			.Where(a => a.Event == action)
			.FirstOrDefault();
		}

		public bool DelegateContains(Action action)
		{
			return DelegateFind(action) == null;
		}

		public void DelegateAdd(Action action, bool doonce = false)
		{
			delegateList.Add(new DelegateExtensibleFlag(action, doonce));
		}

		public bool DelegateRemove(Action action)
		{
			return delegateList.Remove(new DelegateExtensibleFlag(action));
		}

		#endregion

		#region 构造

		public ProgramFlowSecurityExtend()
		{
			
		}

		#endregion

		#region 主要流程

		/// <summary>
		/// 调用所有的已注册扩展事件，注意：这会比使用繁琐的外部方法更慢。
		/// </summary>
		public void InvokedAllDelegate()
		{
			for(int i = 0; i < delegateList.Count; i++)
			{
				if(delegateList[i].Conservate)
					continue;

				try
				{
					delegateList[i].Event.Invoke();
				}
				catch(Exception e)
				{
					delegateList[i].Conservate = true;
					Debug.LogError(e);
				}
			}
		}

		#endregion
	}
}