#!/usr/bin/perl
use warnings;
use strict;
use threads;

package BRscan::Config;
our $port = 54925;
our $printer = "192.168.4.42";
our $myip = "192.168.4.247";
our $debug = 1;
our $work_dir = "/mnt/levant/nfs/tmp";

package BRscan::Listener;
use IO::Socket;
use feature qw/switch/;
#use Data::Dumper;

sub run {
	my $max_len = 2048;
	our $debug = $BRscan::Config::debug;
	my $msg;
	my @processed;

	my $sock = IO::Socket::INET->new(LocalPort => $BRscan::Config::port, Proto => 'udp') or die "socket: $@";

	while ($sock->recv($msg, $max_len)) {
		my $cport = $sock->peerport();
		my $chost = $sock->peerhost();

		print STDERR "Client $chost:$cport said: $msg\n" if $debug;

		# discard first 4 bytes, probably not relevant
		# TODO: what do they mean?
		$msg = substr($msg, 4);

		my %fields;

		for my $field (split(/;/, $msg)) {
			my ($key, $value) = split(/=/, $field);
			next unless defined($key) and defined($value);

			print STDERR "key: \"$key\"; value:  \"$value\"\n" if $debug;

			$fields{$key} = $value;
		}

		# BR likely stands for "brother". use this to determine if it's really a request from a brother device
		next unless $fields{TYPE} eq "BR";

		# ignore multiple requests
		# TODO: clean up old ids
		my $id = $fields{REGID}."-".$fields{SEQ};
		if ($id ~~ @processed) {
			print STDERR "already processed $id. skipping...\n" if $debug;
			next;
		}

		# we only handle the scan button
		next unless $fields{BUTTON} eq "SCAN";

		print STDERR "got $fields{FUNC} scan request\n" if $debug;

		# possible values: FILE, IMAGE, OCR, EMAIL
		given ($fields{FUNC}) {
			when (/IMAGE/) {
				chdir("$BRscan::Config::work_dir");
				system("scan-multi");
			}
			when (/FILE/) {
				chdir("$BRscan::Config::work_dir");
				system("scan-multi --pdf");
			}
		}

		push @processed, $id;
		print STDERR "finished processing $id\n";
	}
}

package BRscan::RegWatcher;
use Net::SNMP;

sub run {
	our $debug = $BRscan::Config::debug;
	my ($session, $error) = Net::SNMP->session(
		-community => "internal", 
		-version => 1, 
		-hostname => $BRscan::Config::printer,
	);

	if (!defined $session) {
		printf STDERR "ERROR: %s.\n", $error;

		exit 1;
	}

	# unhandled are commented out
	my @apps = (
		{appnum => 1, func => "IMAGE"},
		#{appnum => 2, func => "EMAIL"},
		#{appnum => 3, func => "OCR"},
		{appnum => 5, func => "FILE"},
	);

	my @varbindlist;

	for my $app (@apps) {
		push @varbindlist, "1.3.6.1.4.1.2435.2.3.9.2.11.1.1.0";
		push @varbindlist, OCTET_STRING;
		push @varbindlist, "TYPE=BR;BUTTON=SCAN;USER=".$ENV{USER}.";FUNC=".$app->{"func"}.";HOST=".$BRscan::Config::myip.":".$BRscan::Config::port.";APPNUM=".$app->{"appnum"}.";DURATION=360;BRID=;";
	}

	@apps = undef;

	while (1) {
		print STDERR "sending snmp set_request\n" if $debug;

		my $result = $session->set_request(-varbindlist => \@varbindlist);

		if (!defined $result) {
			printf "ERROR in set_request: %s.\n", $session->error();
		}

		sleep 60;
	}
}

package main;
our $debug = $BRscan::Config::debug;

threads->new("BRscan::Listener::run");
threads->new("BRscan::RegWatcher::run");

# wait for everyone before exiting
foreach my $thr (threads->list) { 
        if ($thr->tid && !threads::equal($thr, threads->self)) { 
                print "waiting for thread ".$thr->tid()." to finish\n" if $debug;
                $thr->join; 
        } 
}

__END__

=head1 NAME

brscan-key.pl - Deamon for brother scanner key

=head1 DESCRIPTION

This daemon registers itself with a brother scanner and accepts incoming scanning requests.

=cut