using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.IO;
using System.Collections;

namespace Demo
{
    public class FileListen
    {
        private AutoResetEvent autoResetEvent;
        private string listenPath = @"D:\项目资料\随笔\Demo\listen";
        private Queue fileQueue = new Queue();
        private static object objLock = new object();
        private bool isWait = true;

        public FileListen(string listenPath)
        {
            this.listenPath = listenPath;
            Init();
        }

        private void Init()
        {
            FileSystemWatcher watcher = new FileSystemWatcher(listenPath);
            watcher.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;
            watcher.Filter = "*.txt";
            watcher.EnableRaisingEvents = true;
            watcher.Created += new FileSystemEventHandler(MonitorFileCreate);

            autoResetEvent = new AutoResetEvent(false);

            Thread thread = new Thread(DoWork);
            thread.Start();

            Reload();
        }

        private void Reload()
        {
            DirectoryInfo dires = new DirectoryInfo(listenPath);
            FileInfo[] files = dires.GetFiles().OrderBy(c => c.CreationTime).ToArray();
            foreach (FileInfo file in files)
            {
                if (!fileQueue.Contains(file.FullName))
                {
                    fileQueue.Enqueue(file.FullName);
                    //休眠1秒
                    Thread.Sleep(1000);
                    autoResetEvent.Set();
                }
            }
        }

        private void DoWork()
        {
            Console.WriteLine("DoWork Begin");
            //等待信号
            while (isWait)
            {
                autoResetEvent.WaitOne();
                //锁定 防止并发
                lock (objLock)
                {
                    //获取文件队列信息 并移除
                    string path = fileQueue.Dequeue().ToString();
                    Console.WriteLine("正在处理=>" + path);
                    Console.WriteLine("处理中...");
                    Console.WriteLine("处理完成");
                    File.Delete(path);
                }
            }
        }

        private void MonitorFileCreate(object sender, FileSystemEventArgs e)
        {
            if (e.ChangeType == WatcherChangeTypes.Created)
            {
                try
                {
                    if (!fileQueue.Contains(e.FullPath))
                    {
                        Console.WriteLine("监听文件=>" + e.FullPath);

                        Thread.Sleep(500);
                        fileQueue.Enqueue(e.FullPath);
                        autoResetEvent.Set();
                    }
                }
                catch (Exception ex)
                {
                    //LogHelper.Error(ex.Message + "\r\n" + ex.StackTrace);
                }
            }
        }
    }
}