using HslCommunication.Core;
using HslCommunication.LogNet;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace HslCommunication.Enthernet
{
    /// <summary>
    /// 文件标记对象类
    /// </summary>
    internal class FileMarkId
    {
        /// <summary>
        /// 实例化一个文件标记对象
        /// </summary>
        /// <param name="logNet">日志对象</param>
        /// <param name="fileName">完整的文件名称</param>
        public FileMarkId( ILogNet logNet, string fileName )
        {
            LogNet = logNet;
            FileName = fileName;
        }

        private ILogNet LogNet;                                                     // 日志
        private string FileName = null;                                             // 文件名称
        private Queue<Action> queues = new Queue<Action>( );                        // 操作的队列
        private SimpleHybirdLock hybirdLock = new SimpleHybirdLock( );              // 状态的锁


        /// <summary>
        /// 新增一个文件的操作，仅仅是删除文件
        /// </summary>
        /// <param name="action">对当前文件的操作内容</param>
        public void AddOperation( Action action )
        {
            hybirdLock.Enter( );

            if (readStatus == 0)
            {
                // 没有读取状态，立马执行
                action?.Invoke( );
            }
            else
            {
                // 添加标记
                queues.Enqueue( action );
            }
            hybirdLock.Leave( );
        }


        private int readStatus = 0;

        /// <summary>
        /// 指示该对象是否能被清除
        /// </summary>
        /// <returns>是否能够删除</returns>
        public bool CanClear( )
        {
            bool result = false;
            hybirdLock.Enter( );
            result = readStatus == 0 && queues.Count == 0;
            hybirdLock.Leave( );
            return result;
        }

        /// <summary>
        /// 进入文件的读取状态
        /// </summary>
        public void EnterReadOperator( )
        {
            hybirdLock.Enter( );
            readStatus++;
            hybirdLock.Leave( );
        }

        /// <summary>
        /// 离开本次的文件读取状态
        /// </summary>
        public void LeaveReadOperator( )
        {
            // 检查文件标记状态
            hybirdLock.Enter( );
            readStatus--;
            if (readStatus == 0)
            {
                while (queues.Count > 0)
                {
                    try
                    {
                        queues.Dequeue( )?.Invoke( );
                    }
                    catch (Exception ex)
                    {
                        LogNet?.WriteException( "FileMarkId", "File Action Failed:", ex );
                    }
                }
            }
            hybirdLock.Leave( );
        }
    }
}