#!/usr/bin/perl
#
# The LearningOnline Network with CAPA
#
# Behrouz Minaei
# 9/13/2001, 9/25/2001
# 10/6/2001, 10,9,2001
#
# A CGI script that dynamically outputs a graphical chart for lonstatistics.

use strict;
use GD::Graph::bars;
use GD::Graph::colour;
use GD::Graph::Data;

my ($cid, $Tag, $Max, $PNo, $data) = split(/&/,$ENV{'QUERY_STRING'});

my @data1=split(/\,/,$data);
   
my @xlabels;
for (my $nIdx=0; $nIdx<$PNo; $nIdx++ ) {
    $xlabels[$nIdx]=$nIdx+1;
} 
my @data =(\@xlabels,\@data1);

my $Range;
if ( $PNo > 10 ) {$Range = 30*$PNo;}
else { $Range = 300+30*$PNo; }

if ( $Max < 1 ) { $Max = 1; }
elsif ( $Max < 10 ) { $Max = 10; }
elsif ( $Max < 100 ) { $Max = 100; }

my $MyGraph = GD::Graph::bars->new($Range, 400);

$MyGraph->set( 
    x_label         => 'Problems #',
    y_label         => $Tag,
    title           => 'LON-CAPA Graphical Chart, Course: '.$cid,
    y_max_value     => $Max,
    y_tick_number   => 10,
    y_label_skip    => 1,
    x_label_skip    => 2,
    
    # colors
    dclrs           => [ qw(green lblue lyellow lpurple cyan lorange)],
    
    # shadows
    bar_spacing     => 4,
    shadow_depth    => 1,
    shadowclr       => 'dred',

    transparent     => 0,
) or warn $MyGraph->error; 

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

END

my $BinaryData=$MyGraph->plot(\@data)->png;
undef $MyGraph;
binmode(STDOUT);
open IMG,"|pngtopnm|ppmtogif 2>/dev/null"; # convert into a gif image
print IMG $BinaryData; # output image
$|=1; # be sure to flush before closing
close IMG;