using System.Reactive.Linq;
using System.Reactive.Subjects;
using System.Text;
using CliWrap.EventStream;
using InnovEnergy.Lib.Utils;
using InnovEnergy.Lib.Victron.VictronVRM;
using static System.ConsoleColor;
using static System.StringSplitOptions;

namespace InnovEnergy.RemoteSupportConsole;

public static class VrmConnection
{
    public static async Task<Int32> Open(Installation installation, IReadOnlyList<Detail> details)
    {
        var rsHost = details.RemoteSupportIp();
        var rsPort = details.RemoteSupportPort();

        "starting remote support connection with ".Write();
        installation.Name.WriteLine(Green);

        using var proxy = await OpenProxy(rsHost!, rsPort!);

        "initiating SSH connection\n".WriteLine();
        
        return await Ssh.Interactive(proxy.Host, installation.Name, proxy.User, proxy.Port);

    }

    private static async Task<VrmProxy> OpenProxy(String rsHost, String rsPort)
    {
        "contacting Victron remote support host at ".Write();
        rsHost.Write(Cyan);
        " ... ".Write();

        var stdIn = new Subject<String>();

        var stdInPipe = stdIn
                       .Select(l => l + "\n")
                       .Select(Encoding.UTF8.GetBytes)
                       .AsPipeSource();

        var stdOut = Ssh
                    .Command(rsHost, "ccgxsupport", "22")
                    .WithStandardInputPipe(stdInPipe)
                    .Observe()
                    .OfType<StandardOutputCommandEvent>()
                    .Select(e => e.Text)
                    .Replay();

        var connection = stdOut.Connect();
        
        await stdOut.FirstAsync(l => l.StartsWith("Full readline support"));
        
        "ok".WriteLine();
        "requesting tunnel through port ".Write();
        rsPort.Write(Cyan);
        " ... ".Write();    
        
        stdIn.OnNext($"proxyport {rsPort}");

        var connectMsg = await stdOut.FirstAsync(l => l.StartsWith("You can now connect"));
        
        "ok".WriteLine();

        var portUserHost = connectMsg.Split(" ", RemoveEmptyEntries);
        var userHost     = portUserHost[^1].Split("@");
        var user         = userHost[0];
        var host         = userHost[1];
        var port         = portUserHost[^2];
        
        return new VrmProxy(connection, user, host, port);
    }

    public static IObservable<CommandEvent> Log(this IObservable<CommandEvent> es)
    {
        return es.Do(e => Console.WriteLine(Log(e)));
    }

    private static String Log(CommandEvent e) => e switch
    {
        StandardOutputCommandEvent so => "=> " + so.Text,
        StandardErrorCommandEvent  se => "!! " + se.Text,
        StartedCommandEvent           => "START",
        ExitedCommandEvent            => "EXIT",
        _                             => "UNKNOWN MESSAGE: " + e.GetType().Name
    };
}


// ReSharper disable CommentTypo

// $ ssh ccgxsupport@3.72.120.57
// Welcome to the Victron remote support tunnel creator.
//
// You will given a one-time tunnel. SSH authentication to
// the Color Control is done with your SSH public key.
//
// *****************************************************************************
// *                               IMPORTANT NOTE:                             *
// *                                                                           *
// * There are now multiple SSH support hosts. Logging in directly             *
// * is not officially supported behavior, because you may end up on the wrong *
// * server. A script called 'rs' to use the new format '1.2.3.4;45630' is     *
// * available. Ask your Victron contact to supply you with it.                *
// *****************************************************************************
//
// The proxy opened up to the CCGX will be restricted to your IP: 145.40.192.17
//
// Commands are:
//  proxyport [port]  - take color control [port] and temporarily make it available to the outside.
//  iptoport [ip]     - show the ports being listened on by that IP. Note, you do need to know
//                      which server the device is connected to. Currently, possibilites are:
//                      - 84.22.108.49 (EU)
//                      - 84.22.107.120 (EU)
//                      - 3.69.217.175 (EU)
//                      - 3.72.120.57 (EU)
//                      - 3.25.10.245 (AUS Sydney)
//                      - 35.165.124.40 (USA West)
//                      - 13.244.154.199 (South Africa)
//                      - 13.246.113.18 (South Africa)
//                      A good start would be the last known, as seen on the diagnostics page.
//  exit              - exits the shell and all tunnels you set up
//
// Full readline support (command history and editing) is available.
//
// proxyport 24337
// You can now connect to the CCGX with: ssh -o 'UserKnownHostsFile=/dev/null' -o 'StrictHostKeyChecking=no' -o 'ServerAliveInterval=60' -p 4001 root@3.72.120.57