package Business::CreditCard::Obscure;

use strict;
use warnings;

sub new {

	my ($pack,%in) = @_;

	my $hash = {};

	$hash->{'cardnum'} = defined($in{'cardnum'}) ? $in{'cardnum'} : undef;
	$hash->{'head'} = defined($in{'head'}) ? $in{'head'} : 0;
	$hash->{'tail'} = defined($in{'tail'}) ? -$in{'tail'} : -4;
	$hash->{'replacement'} = defined($in{'replacement'}) ? $in{'replacement'} : '*';

	return bless $hash, $pack;
}

sub obscure {

	my ($check,%in) = @_;
	my $self = ($check eq __PACKAGE__) ? $check->new(%in) : $check;

	$self->{'cardnum'} = $in{'cardnum'} if ($in{'cardnum'});
	$self->{'head'} = $in{'head'} if ($in{'head'});
	$self->{'tail'} = - $in{'tail'} if ($in{'tail'});
	$self->{'replacement'} = $in{'replacement'} if ($in{'replacement'});

	return "cardnum not found" unless (defined($self->{'cardnum'}));
	return "head not found" unless (defined($self->{'head'}));
	return "tail not found" unless (defined($self->{'tail'}));
	return "replacement not found" unless (defined($self->{'replacement'}));

	my $cardnum = $self->{'cardnum'};

	substr(	$cardnum,
			$self->{'head'},
			$self->{'tail'}
			) =~ s/./$self->{'replacement'}/g;

	return $self->{'obscured'} = $cardnum;

}

1;