#!/usr/bin/perl
use Chart::Graph::Gnuplot qw(gnuplot);
use Getopt::Long;
use Pod::Usage;
use strict;
use warnings;

my $title = 'Burndown';
my $pngname = 'burndown.png';
GetOptions( 'title=s'   => \$title,
            'pngname=s' => \$pngname,
            'help'      => sub {pod2usage({-verbose => 1}); exit},
          ) or do {pod2usage({-verbose => 1}); exit};

my @dates;
my @totals;
my @todos;
while(<>) {
    next if /^YYYY/; # ignore header
    my ($date, $total, $todo) = split /\s+/;
    push @dates, $date;
    push @totals, $total;
    push @todos, $todo;
}
die "No data read!\n" unless @totals;

# Make the y range 10% larger than the highest value
my $ymax = (sort {$a <=> $b} @totals)[-1];
$ymax *= 1.1; 

gnuplot({"title" => $title,
         "x-axis label" => "Date",
         "y-axis label" => "Points",
         "output type" => "png",
         "output file" => $pngname,
         "yrange"  => "[0:$ymax]",
         "xdata"    => "time",
         "format"  => ["x", "%m/%d"],
         "timefmt" => '%Y/%m/%d',
         },
         [{title => "Total work",
           style => "lines",
           type  => "columns"}, \@dates, \@totals],
         [{title => "Remaining work",
           style => "lines",
           type  => "columns"}, \@dates, \@todos],
);

__END__

=head1 NAME

hwd-burnchart -- Create burndown charts from hwd burndown output

=head1 SYNOPSIS

  hwd --burndown foo.txt | hwd-burnchart --title "Project Foo"

Options:

  --title       Use the given title (defaults to "Burndown")
  --pngname     Write the chart to this filename (defaults to burndown.png)
  --help        Show this help

=head1 OVERVIEW

The burndown chart shows the history of the task totals and of how much
work remains to be done.  The remaining work should approach zero as the 
project completes.

=head1 TODO

=head2 Text based graphs

=head1 AUTHORS

Luke Closs C<< <lukec@activestate.com> >>

=head1 COPYRIGHT

Copyright 2005 by Luke Closs C<< <lukec@activestate.com> >>.

This program is free software; you can redistribute it and/or 
modify it under the same terms as Perl itself.

See L<http://www.perl.com/perl/misc/Artistic.html>.

=cut