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

namespace instabot
{
    class Proxy
    {

        private static bool PingHost(string strIP, int intPort)
        {
            bool blProxy = false;
            try
            {
                TcpClient client = new TcpClient(strIP, intPort);

                blProxy = true;
            }
            catch (Exception ex)
            {

                return false;
            }
            return blProxy;
        }

        public  static string GetProxy()
        {
            string proxyip = "";
            var urlAddress = "https://www.us-proxy.org";
            //<td>35.190.133.37</td><td>80</td><td class='hm'>United States</td><td>anonymous</td><td class='hm'>no</td>

            WebRequest reqGET = System.Net.WebRequest.Create(urlAddress);
            WebResponse resp;

            try
            {
                resp = reqGET.GetResponse();
                System.IO.Stream stream = resp.GetResponseStream();
                System.IO.StreamReader sr = new System.IO.StreamReader(stream);
                string s = sr.ReadToEnd();

                string pattern = @"(<td>\d+.\d+.\d+.\d+</td><td>\d+</td><td>\w+</td><td class='hm'>\w+ \w+</td><td>\w+</td><td class='hm'>\w+</td><td>\w+</td>)";
                Regex regex = new Regex(pattern);

                Match match = regex.Match(s);
                proxyip = "";
                while (match.Success)
                {
                    var ip_port = match.Groups[1].Value.Replace(" class='hm'", "");
                    string[] keys = ip_port.Split(new[] { "</td><td>" }, StringSplitOptions.None);
                    for (int i = 0; i < keys.Length; i++)
                    {
                        keys[i] = keys[i].Replace("</td>", "").Replace("<td>", "");
                    }
                    Console.WriteLine(keys[0]+':'+keys[1]+" "+keys[6]);
                    if (keys[6] == "yes")
                    {
                        if (PingHost(keys[0], int.Parse(keys[1])))
                            return proxyip += "https://" + keys[0] + ':' + keys[1];
                    }
                    else
                    {
                        if (PingHost(keys[0], int.Parse(keys[1])))
                           return proxyip += "http://" + keys[0] + ':' + keys[1];
                    }
                    match = match.NextMatch();
                }
            }
            catch (WebException)
            {

            }
            return "Error";
        }
    }
}