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

namespace SafeMobileLib
{
    public class IP_Helpers
    {
        public static string GetInterface(string IPstr)
        {
            string strInterface = "";
            try
            {
                string[] arrStr = IPstr.Split(".".ToCharArray());
                int lastPartOfIP = Convert.ToInt32(arrStr[3]);
                arrStr[3] = (lastPartOfIP + 1).ToString();
                strInterface = arrStr[0] + "." + arrStr[1] + "." + arrStr[2] + "." + arrStr[3];
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error GEtting interface");
                Console.WriteLine(ex.ToString());
            }
            return strInterface;
        }

        public static string GetReverse_Interface(string IPstr)
        {
            string strInterface = "";
            try
            {
                string[] arrStr = IPstr.Split(".".ToCharArray());
                int lastPartOfIP = Convert.ToInt32(arrStr[3]);
                arrStr[3] = (lastPartOfIP - 1).ToString();
                strInterface = arrStr[0] + "." + arrStr[1] + "." + arrStr[2] + "." + arrStr[3];
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error GEtting interface");
                Console.WriteLine(ex.ToString());
            }
            return strInterface;
        }

        public static async Task<string> GetPublicIPAsync()
        {
            return await Task.Run(() => GetPublicIP());
        }

        public static string GetPublicIP()
        {
            string a4 = "";
            try
            {
                string url = "http://checkip.dyndns.org";
                System.Net.WebRequest req = System.Net.WebRequest.Create(url);
                System.Net.WebResponse resp = req.GetResponse();
                System.IO.StreamReader sr = new System.IO.StreamReader(resp.GetResponseStream());
                string response = sr.ReadToEnd().Trim();
                string[] a = response.Split(":".ToCharArray());
                string a2 = a[1].Substring(1);
                string[] a3 = a2.Split("<".ToCharArray());
                a4 = a3[0];
                if(a4 == "")
                        a4 = new WebClient().DownloadString(@"http://icanhazip.com").Trim();
            }
            catch { a4 = new WebClient().DownloadString(@"http://icanhazip.com").Trim(); }
            return a4;
        }


        

    }


}