using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.NetworkInformation;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace FileSend
{
    internal class Helper
    {
        /// <summary>
        /// 匹配IP地址是否合法
        /// </summary>
        /// <param name="ip">当前需要匹配的IP地址</param>
        /// <returns>true:表示合法</returns>
        public static bool MatchIP(string ip)
        {
            bool success = false;
            if (!string.IsNullOrEmpty(ip))
            {
                //判断是否为IP
                success = Regex.IsMatch(ip, @"^((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?)$");
            }
            return success;
        }

        /// <summary>
        /// 匹配端口是否合法
        /// </summary>
        /// <param name="port"></param>
        /// <returns>true：表示合法</returns>
        public static bool MatchPort(int port)
        {
            bool success = false;
            if (port >= 0 && port <= 65535)
            {
                success = true;
            }
            return success;
        }


        /// <summary>
        /// 检查IP是否可ping通
        /// </summary>
        /// <param name="strIP">要检查的IP</param>
        /// <returns>是否可连通【true:表示可以连通】</returns>
        public static bool CheckIPIsPing(string strIP)
        {
            if (!string.IsNullOrEmpty(strIP))
            {
                if (!MatchIP(strIP))
                {
                    return false;
                }
                // Windows L2TP VPN和非Windows VPN使用ping VPN服务端的方式获取是否可以连通
                Ping pingSender = new Ping();
                PingOptions options = new PingOptions();

                // 使用默认的128位值
                options.DontFragment = true;

                //创建一个32字节的缓存数据发送进行ping
                string data = "testtesttesttesttesttesttesttest";
                byte[] buffer = Encoding.ASCII.GetBytes(data);
                int timeout = 120;
                PingReply reply = pingSender.Send(strIP, timeout, buffer, options);

                return (reply.Status == IPStatus.Success);
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// 连续几次查看是否某个IP可以PING通
        /// </summary>
        /// <param name="strIP">ping的IP地址</param>
        /// <param name="waitMilliSecond">每次间隔时间，单位：毫秒</param>
        /// <param name="testNumber">测试次数</param>
        /// <returns>是否可以连通【true:表示可以连通】</returns>
        public static bool MutiCheckIPIsPing(string strIP, int waitMilliSecond, int testNumber)
        {
            for (int i = 0; i < testNumber - 1; i++)
            {
                if (CheckIPIsPing(strIP))
                {
                    return true;
                }
                Thread.Sleep(waitMilliSecond);
            }

            return CheckIPIsPing(strIP);
        }
    }
}