#!/usr/bin/perl

=head1 NAME

ExtendedURI - Convert a given URI into an encoded format that can be used to lookup via DNS on Mailspike EBL

=cut

=head1 METHODS

=over 4

=item encode($url)

Returns the encoded URI.

Example:

	encode("http://example.com/XX/somelargerpath/that?foo=bar")'

	returns:

	bar.foo.8c9d53a8.645bd428.XX.example.com

=cut

package ExtendedURI;

use strict;
use vars qw(@ISA);
use bytes;
use Digest::MD5 qw{ md5_hex};
use String::CRC32;

my $MAXHOSTSIZE = 112;
my $MAXPARTSIZE = 8;

sub sub_encode {
	my $string	= shift;
	my $maxpart	= shift || $MAXPARTSIZE;
        #return  '"'.$string."-".substr(md5_hex($string),0,34).'"';
        #return  '"'.$string."-".substr(md5_hex($string),0,$maxpart).'"';
        return  substr(md5_hex($string),0,$maxpart);
}
sub encode {
	my $url		= shift || return '';
	my $rbl		= shift || '';
	my $maxpart	= shift || $MAXPARTSIZE;
	my $max		= shift || $MAXHOSTSIZE;
	$rbl = ".$rbl" if $rbl;

        if ( $url!~/^\w+:\/\// ) {
                $url="http://".$url;
        }
        $url=~/https?:\/\/(.+?)(\/|$)(.*)/;
        my $domain=$1;
	$max -= (length($domain) + length($rbl) + $maxpart +1);
        my $path="/".$3 if $3;
        my $result;

        if ( $path ) {
                my @slices=split(/[\/\?\=\&]/,$path); # Split path into slices
                shift(@slices); # remove empty slice

		# Encode it
		while ((my $slice = shift(@slices)) && ($max > ($maxpart+1))) {
			substr($path,0,length($slice)+1) = '';
               		$result =  sub_encode($slice,$maxpart).".$result";
			$max -= ($maxpart +1);
		}
		chop($result);
		$result = sub_encode($path,$maxpart).".$result"
			if $path;
		return "$result.$domain$rbl";
        } else { 
		# If no path detected, just return the original domain
		return $domain;
	}
}

42;