#!/usr/bin/perl

# VDR SVDRP Peer Demo
#
# (C) 2017 by Klaus Schmidinger <Klaus.Schmidinger@tvdr.de>

use Getopt::Std;
use IO::Socket;
use IO::Select;

$Usage = qq{
Usage: $0 options

Options: -c       communicate with peer VDR
         -v       be verbose
};

die $Usage if (!getopts("cv"));

$Communicate = $opt_c || 0;
$Verbose     = $opt_v || 0;

$SvdrpPort = 6419;
$MyName = "peerdemo";

# Open TCP and UDP sockets:

$TcpSocket = new IO::Socket::INET(Listen => 5, LocalPort => $SvdrpPort, Proto => "tcp", ReusePort => 1) || die "$!";
$UdpSocket = new IO::Socket::INET(             LocalPort => $SvdrpPort, Proto => "udp", ReusePort => 1) || die "$!";
$SvdrpSelect = new IO::Select($TcpSocket);
setsockopt($UdpSocket, SOL_SOCKET, SO_RCVTIMEO, pack('L!L!', 0, 1000)); # 1ms timeout on UDP socket

# Send UDP broadcast:

$BcastSocket = new IO::Socket::INET(PeerAddr => '255.255.255.255', PeerPort => $SvdrpPort, Proto => "udp", Broadcast => 1) || die "$!";
$BcastMsg = "SVDRP:discover name:$MyName port:6419 vdrversion:20309 apiversion:20309 timeout:300";
Log('>', $BcastSocket, $BcastMsg);
print($BcastSocket $BcastMsg);
$BcastSocket->close();

# Listen on UDP and TCP socket:

while (1) {
      if ($UdpSocket->recv($Request, 1024)) {
         if ($SkippedFirstUdpPacket++) { # the first one is the one we sent, so skip it
            Log('<', $UdpSocket, $Request);
            $Request .= " "; # for easier parsing
            my $Name       = Extract($Request, "name");
            my $Port       = Extract($Request, "port");
            my $VdrVersion = Extract($Request, "vdrversion");
            my $ApiVersion = Extract($Request, "apiversion");
            my $Timeout    = Extract($Request, "timeout");
            my $PeerHost   = $UdpSocket->peerhost();
            print("found VDR '$Name' at $PeerHost with SVDRP port '$Port'\n");
            }
         }
      if (my @Ready = $SvdrpSelect->can_read(0.01)) {
         for my $fh (@Ready) {
             if ($fh == $TcpSocket) {
                # accept connection:
                my $new = $TcpSocket->accept();
                Log('<', $new, "incoming TCP connection");
                # send mandatory response to simulate an SVDRP host:
                my $Prompt = "220 $MyName SVDRP VideoDiskRecorder 2.3.9; Wed Nov 29 17:00:29 2017; ISO-8859-1";
                Log('>', $new, $Prompt);
                print($new $Prompt);
                if ($Communicate) {
                   # add incoming connection to select:
                   $SvdrpSelect->add($new);
                   }
                else {
                   # close connection:
                   $new->close;
                   }
                }
             else {
                # process connection:
                my $Request;
                if ($fh->recv($Request, 1024)) {
                   Log('<', $fh, $Request);
                   if ($Request =~ /^LSTT/) {
                      my $Response = "550 No timers defined";
                      Log('>', $fh, $Response);
                      print($fh "$Response\n");
                      }
                   }
                # close connection:
                $SvdrpSelect->remove($fh);
                $fh->close;
                }
             }
         }
      }

# Tools:

sub Extract
{
  my ($s, $n) = @_;
  return ($s =~ / $n:([^ ]*) /)[0];
}

sub Log
{
  return unless ($Verbose);
  my ($Dir, $Socket, $Msg) = @_;
  printf("SVDRP %s [%s:%s] %s\n", $Dir, $Socket->peerhost(), $Socket->peerport(), $Msg);
}