<?PHP
/**
 * Created by Gachl
 * admin@bloodisgood.org
 * Please give credit where credit belongs.
 *
 * Resources used:
 * * http://php.net/pack
 * * https://developer.valvesoftware.com/wiki/Source_RCON_Protocol
 * * My own Rust server
 *
 * License: http://creativecommons.org/licenses/by-nc-sa/4.0/
 */
class RustRcon
{
    private $debug = false; // activate this flag if you want to see verbose communication
    private $read_timeout = 2; // 2 seconds read timeout
    private $packet_id = 0;
    private $stream;

    public function __construct($server, $port, $rcon_password)
    {
        $this->connect($server, $port, $rcon_password);
    }

    private function connect($server, $port, $rcon_password)
    {
        $error = 0;
        $errorstring = "";

        $this->stream = @fsockopen("tcp://$server", intval($port), $error, $errorstring);

        if ($error !== 0 || $errorstring !== "")
            throw new Exception("Could not connect to rust server: Error($error) $errorstring.");

        stream_set_timeout($this->stream, 1); // don't take too long for requests
        $auth = $this->transmit($rcon_password, 3); // 3 = Auth flag
    }

    public function __destruct()
    {
        $this->Disconnect();
    }

    public function Disconnect()
    {
        fclose($this->stream);
    }

    public function Send($command)
    {
        return $this->transmit($command);
    }

    private function transmit($packet_body, $packet_type = 2)
    {
        $packet_id = ++$this->packet_id;
        $request = pack('VV', $packet_id, $packet_type) . $packet_body . "\x00\x00";
        $request = Pack('V', strlen($request)) . $request;

        if ($this->debug)
        {
            echo "> LEN " . strlen($request) . "\n" .
                     "> ID $packet_id\n" .
                     "> TYPE $packet_type\n" .
                     "> BODY $packet_body\n\n\n";
        }

        fwrite($this->stream, $request); // Give no shits about how much data was sent
        return $packet_id;
    }

    public function Read()
    {
        if (feof($this->stream))
            return null;

        // Let's do this
        $size = fread($this->stream, 4);
        if (strlen($size) !== 4)
            return null; // Invalid!

        $size = unpack('V', $size);
        $id = unpack('V', fread($this->stream, 4));
        $type = unpack('V', fread($this->stream, 4));
        $body = fread($this->stream, $size[1] - 8);

        if ($this->debug)
        {
            echo "< LEN ${size[1]}\n" .
                     "< ID ${id[1]}" . ($id[1] == 0xffffffff ? ' (-1)' : '') . "\n" .
                     "< TYPE ${type[1]}\n" .
                     "< BODY " . $body . "\n\n\n";
        }

        if ($id[1] == 0xffffffff)
            throw new Exception("Rcon password invalid.");

        return new RustRconResponse($id[1], $body);
    }
}

class RustRconResponse
{
    private $id = -1;
    private $body = null;

    public function __construct($id, $body)
    {
        $this->id = intval($id);
        $this->body = trim($body);
    }

    public function ID()
    {
        return $this->id;
    }

    public function Response()
    {
        return $this->body;
    }
}