#!/usr/bin/perl

# The LearningOnline Network with CAPA
# barcode.png - A CGI script that dynamically outputs a barcode.
#
# $Id: barcode.png,v 1.12 2005/04/07 06:56:21 albertel Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
###

# I'm using format=Code39.
# The valid formats are
# EAN13, EAN8, UPCA, UPCE, NW7, Code39,
# ITF, IATA2of5, Matrix2of5, and COOP2of5.

# Example usage: /cgi-bin/barcode.gif?encode=12345*31*MSUL1

use strict;
use GD::Barcode::Code39;

$|=1;   # Autoflush after each print/write
my %env;
foreach (split(/&/,$ENV{'QUERY_STRING'})) {
    my ($name, $value) = split(/=/,$_);
    $value =~ tr/+/ /;
    $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
    if ($name eq 'encode') {
	$env{'form.'.$name}=$value;
    }
}

# Tell the server we are sending a png graphic
print <<END;
Content-type: image/png

END

unless(defined($env{'form.encode'}) and length($env{'form.encode'})) {
    $env{'form.encode'}='***ERROR***UNDEFINED***';
}
my $text = '*'.uc($env{'form.encode'}).'*';
my $oGdBar=GD::Barcode::Code39->new($text);
if ($GD::Barcode::errStr or !defined($oGdBar)) {
    warn($GD::Barcode::errStr);
    $oGdBar=GD::Barcode::Code39->new('***ERROR***INVALID***');
}
my $bindata=$oGdBar->plot->png; # create barcode image
undef $oGdBar;
binmode(STDOUT);
#open OUT,"|pngtopnm|ppmtogif 2>/dev/null"; # convert into gif image
#print OUT $bindata; # output image
#$|=1; # be sure to flush before closing
#close OUT;
print $bindata;