using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Net.Sockets;

using System.Reflection;

using System.Text;

using System.Threading.Tasks;

using System.Xml;

namespace NETworkManager.Models.Network

{

public static class Whois

{

#region Variables

private static readonly string WhoisServerFilePath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "Resources", "WhoisServers.xml");

private static readonly List<WhoisServerInfo> WhoisServerList;

private static readonly Lookup<string, WhoisServerInfo> WhoisServers;

#endregion

#region Constructor

static Whois()

{

var document = new XmlDocument();

document.Load(WhoisServerFilePath);

WhoisServerList = new List<WhoisServerInfo>();

foreach (XmlNode node in document.SelectNodes("/WhoisServers/WhoisServer"))

{

if (node == null)

continue;

WhoisServerList.Add(new WhoisServerInfo(node.SelectSingleNode("Server")?.InnerText, node.SelectSingleNode("TLD")?.InnerText));

}

WhoisServers = (Lookup<string, WhoisServerInfo>)WhoisServerList.ToLookup(x => x.Tld);

}

#endregion

#region Methods

public static Task<string> QueryAsync(string domain, string whoisServer)

{

return Task.Run(() => Query(domain, whoisServer));

}

public static string Query(string domain, string whoisServer)

{

var tcpClient = new TcpClient(whoisServer, 43);

var networkStream = tcpClient.GetStream();

var bufferedStream = new BufferedStream(networkStream);

var streamWriter = new StreamWriter(bufferedStream);

streamWriter.WriteLine(domain);

streamWriter.Flush();

var streamReader = new StreamReader(bufferedStream);

var stringBuilder = new StringBuilder();

while (!streamReader.EndOfStream)

stringBuilder.AppendLine(streamReader.ReadLine());

return stringBuilder.ToString();

}

public static string GetWhoisServer(string domain)

{

var domainParts = domain.Split('.');

// TLD to upper because the lookup is case sensitive

return WhoisServers[domainParts[domainParts.Length - 1].ToUpper()].FirstOrDefault()?.Server;

}

#endregion

}

}