#!/usr/bin/perl -wT
# filter.cgi

use strict;
use CGI qw(:standard);
use Image::Magick;

my %filters = (Charcoal => 'amount',
		   OilPaint => 'radius',
		   Spread => 'amount',
		   Solarize => 'factor',
		   Swirl => 'degrees',
		   Implode => 'factor',
		   Flip => undef,
		   Emboss => undef
		);

my $filename = "kyla_smile.jpg";

(my $filtered = $filename) =~ s!(\.\w*$)!${filename}_filtered$1!i;

if (!param('doit')) {
	print header,
		start_html("Filter Image");
	print h2(param('error')) if param('error');
	print h2("Choose Filter"),
		start_form(-action=>"filter.cgi");

	for (sort keys %filters) {
		print qq($_ <INPUT TYPE="radio" NAME="filter" VALUE="$_"> );
		defined($filters{$_})
			? print qq($filters{$_} <INPUT TYPE="text" NAME="$_" SIZE=3><P>)
			: print qq(<P>);
	}

	print submit(-value=>"Alter Image", -name=>"doit"),
		end_form,
		end_html;
} else {
	my $filter = param('filter') || error("Please choose a filter");
	my $amount = param($filter);
	my $q = new Image::Magick;
	error("Couldn't read in image file") if $q->Read($filename);
	defined($filters{$filter})
		? $q->$filter($filters{$filter} => $amount)
		: $q->$filter();
	$q->Write($filtered);
	print redirect($filtererd);
}

sub error {
	my $error = CGI::escape(@_);
	print "Location: filter.cgi?error=$error\n\n";
	exit;
}