#!/usr/bin/perl -w
# vim:ts=4:sw=4
# Summary:      CGI to count prevalence of birth months and draw pretty graphs. 
# Author:       Chris Ball. <chris@cpan.org>
# Function:     To do silly things with graphs.

use CGI qw/-no_xhtml :standard/;	
use CGI::Carp qw(fatalsToBrowser);  
use GD::Graph::pie;					
use strict;				     		
my ($name, $month);  				
my @data;							
my (%name_month, %halfyear_freq, %season_freq);	
my $filename = "birthmonths.dat";   

# Going to print the HTML page before input.
print header,                      # Print the HTTP headers. 
      start_html('Birth months.'), h1('Birth months.'), start_form,
      "Your name: ", textfield('name'), br, 
      "Your birth month (1-12): ", textfield('month'), p, submit, 
      end_form, hr;			
	
# If we have input, write it to the flat file. 
if ( param() ) {  
    $name   = param('name');       # Set local variables to the input 
    $month  = param('month');      # from the form. 
  
    open(FILE, ">>$filename");     # open $filename for append/create 
    if ($month > 0 and $month < 13) { print FILE "$name||$month\n"; }
    close(FILE);                   # reached EOF - close the file.
}
    
# Read the hashes from the file.
open(FILE, "<$filename");          # open $filename for read
while (<FILE>) { ($name, $month) = split(/\|\|/); $name_month{$name} = $month; }

# Prep a table.
print '<br><table border=1><tr><th>Name</th><th>Birthmonth</th></tr>';

# Print name => month, create a hash of test => frequency.
while (($name, $month) = each %name_month) { 
	print "<tr><td>$name</td><td>$month</td>";
	if (($month > 0) and ($month < 13)) {
		$season_freq{($month<10 and $month>3) ?"summer":"winter"}++;
		$halfyear_freq{($month>0 and $month<7) ?"onetosix":"seventotwelve"}++;
	}
}

# Tidy up the table.
print '</tr></table><br clear="all">';

# Print the totals.
print "Total number of entries: " . scalar(keys(%name_month)) . "<br><br>";
print "January-June: $halfyear_freq{onetosix}<br>";
print "July-December: $halfyear_freq{seventotwelve}<br><br>";

print "April-September (Summer): $season_freq{summer}<br>";
print "October-August (Winter): $season_freq{winter}<br>";

# Prepare space for the image.
print '<hr><div align="center">';
print '<img src="halfyear.png"> <img src="season.png"></div><hr>';

# Graph one: 1-6/6-12
# Prepare GD's two-dimensional array.
$data[0]=(["Months 1-6","Months 7-12"]);
$data[1]=([$halfyear_freq{onetosix},$halfyear_freq{seventotwelve}]);

# Plot. 
my $graph = GD::Graph::pie->new(400, 300);
$graph->set( title => 'Geek birthdays - Half-year by Frequency.' );
my $gd = $graph->plot(\@data);
open(IMG, '>halfyear.png') or die $!; binmode IMG; print IMG $gd->png;

# Graph two: summer/winter
# Prepare GD's two-dimensional array.
$data[0]=(["Summer","Winter"]);
$data[1]=([$season_freq{summer},$season_freq{winter}]);

# Plot.
my $graph = GD::Graph::pie->new(400, 300);
$graph->set( title => 'Geek birthdays - Season by Frequency.' );
$graph->set( dclrs => [ qw(cyan lorange) ] );
my $gd = $graph->plot(\@data);
open(IMG, '>season.png') or die $!; binmode IMG; print IMG $gd->png;

print end_html; 		     		# wrap up the html..