#!/usr/bin/perl

use warnings;
use strict;

use JSON::Parse;
use LWP::UserAgent;
use CGI;

use Data::Dumper;

my $query = new CGI;

print CGI::header(-charset=>'utf-8');
print CGI::start_html(-title => "XKCD Explorer");

print "<h1>XKCD Explorer</h1>\n";

my $width = $query->url_param('width') || 1024;
my $height = $query->url_param('height') || 117;
my $referer = $query->url_param('referer') || 'http://xkcd.com/';
my $underscore = $query->url_param('underscore') || 13;
my $user_agent = $query->url_param('user-agent') || 'Mozilla/5.0 (Windows; U; Windows NT 5.2; en-GB; rv:1.9.2.9) Gecko/20100824 Firefox/3.6.9';

if($query->url_param('submit'))
{
	# http://umwelt.xkcd.com/story/ghenkEggov8?callback=waldoCallback&w=1042&h=117&r=&_=13
	# Fetch the JSON from xkcd.
	my $ua = LWP::UserAgent->new();
	$ua->agent($user_agent);
	my $url = "http://umwelt.xkcd.com/story/ghenkEggov8?callback=waldoCallback&w=${width}&h=${height}&r=${referer}&_=${underscore}";
	my $request = HTTP::Request->new(GET => $url);
	$request->header( 'Referer' => 'http://imgs.xkcd.com/static/waldo.js');
	my $response = $ua->request($request);
	my $content = $response->decoded_content() if($response->is_success());
	
	print "<pre>$url</pre>\n";
	print "<pre>$content</pre>\n";
	$content =~ s/^waldoCallback\(//;
	$content =~ s/\)$//;
	my $json = JSON::Parse::json_to_perl($content);
	print "<br><br><br>";
	print "<pre>\n";
	print Dumper($json);
	print "\n";
	print "</pre>\n";

	# Emit a comic
	foreach my $panel (@{$json->{panels}})
	{
		my $image_url = $panel->{images}->[0]->{url};
		print "<img src='http://imgs.xkcd.com/a1panels/${image_url}'>\n";
	}
}

print "<br><hr><br>\n";

# Emit the form
print "<form method='GET' action='xkcd-viewer.pl'>\n";
print "Width: <input type='text' name='width' value='$width' size='5' maxlength=10><br>\n";
print "Height: <input type='text' name='height' value='$height' size='5' maxlength=10><br>\n";
print "Referer: <input type='text' name='referer' value='$referer' size='75' maxlength=1000><br>\n";
print "Underscore: <input type='text' name='underscore' value='$underscore' size='75' maxlength=1000><br>\n";
print "User-Agent: <input type='text' name='user-agent' value='$user_agent' size='75' maxlength=1000><br>\n";
print "<br><button name='submit' value='submit'>Submit</button>\n";
print "</form>\n";

print CGI::end_html();


# Draw the form