// /**
//  * File: SSH.cs
//  * Author: haraldwolff
//  *
//  * This file and it's content is copyrighted by the Author and / or copyright holder.
//  * Any use wihtout proper permission is illegal and may lead to legal actions.
//  *
//  *
//  **/
using System;
using Renci.SshNet;
using ln.types;
using Renci.SshNet.Common;
using System.Net.Sockets;
using ln.types.net;
using ln.skyscanner.crawl.service;
using ln.logging;
namespace ln.skyscanner.crawl.tests
{
    public class SSH : CrawlService
    {
        public SSH()
            : base("ssh")
        {
        }

        public static bool CanConnect(CrawledHost crawledHost)
        {
            int sshPort = crawledHost.GetHint<int>("ssh.port", -1);
            IPv4 sshIP = crawledHost.GetHint<IPv4>("ssh.ip", null);
            string sshUser = crawledHost.GetHint<string>("ssh.login", null);
            string sshPassword = crawledHost.GetHint<string>("ssh.password", null);

            if ((sshPort == -1) || !CanConnect(crawledHost,sshIP,sshPort,sshUser,sshPassword))
            {
                if (!Scan(crawledHost))
                {
                    crawledHost.SetHint("ssh.port", -1);
                    crawledHost.SetHint("ssh.ip", null);
                    crawledHost.SetHint("ssh.login", null);
                    crawledHost.SetHint("ssh.password", null);
                    crawledHost.SetHint("ssh.version", null);
                    return false;
                }
            }
            return true;
        }

        private static bool Scan(CrawledHost crawledHost)
        {
            foreach (IPv4 ip in crawledHost.IPAddresses)
            {
                foreach (int port in new int[] { 13022, 22 })
                {
                    if (crawledHost.HasHint(String.Format("tcp.{0}",port)) && crawledHost.GetHint<bool>(String.Format("tcp.{0}", port)))
                    try
                    {
                        foreach (Credential credential in SkyScanner.Instance.Crawler.Credentials)
                        {
                            Logging.Log(LogLevel.DEBUG, "SSH trying {0}:{1}...", credential.Username, credential.Password.Substring(0, 4));

                            if (CanConnect(crawledHost, ip, port, credential.Username, credential.Password, true))
                                return true;
                        }
                    } catch (SocketException)
                    {
                        continue;
                    }
                }
            }
            return false;
        }

        private static bool CanConnect(CrawledHost crawledHost, IPv4 host, int port, string username, string password,bool throwe = false)
        {
            using (SshClient client = new SshClient(host.ToString(), port, username, password))
            {
                client.ConnectionInfo.Timeout = TimeSpan.FromSeconds(5);
                try
                {
                    String authBanner = null;
                    client.ConnectionInfo.AuthenticationBanner += (object sender, AuthenticationBannerEventArgs e) => authBanner = e.BannerMessage;

                    client.Connect();

                    crawledHost.SetHint("ssh.port", client.ConnectionInfo.Port);
                    crawledHost.SetHint("ssh.ip", host);
                    crawledHost.SetHint("ssh.login", client.ConnectionInfo.Username);
                    crawledHost.SetHint("ssh.password", password);
                    crawledHost.SetHint("ssh.version", client.ConnectionInfo.ServerVersion);
                    crawledHost.SetHint("ssh.authbanner", authBanner);

                    client.Disconnect();
                    return true;
                }
                catch (SshException sshe)
                {
                    Logging.Log(sshe);
                }
                catch (SocketException)
                {
                    return false;
                }
            }
            return false;
        }

        public override bool Check(Crawl crawl)
        {
            return CanConnect(crawl.Host);

        }

        public override bool HostProvidesOption(Crawl crawl, params object[] parameters)
        {
            return crawl.Host.GetHint<IPv4>("ssh.ip", null) != null;
        }
    }
}