package Algorithm::CheckDigits::M97_001;
use 5.006;
use strict;
use warnings;
use integer;
our $VERSION = '0.53';
our @ISA = qw(Algorithm::CheckDigits);
sub new {
my $proto = shift;
my $type = shift;
my $class = ref($proto) || $proto;
my $self = bless({}, $class);
$self->{type} = lc($type);
return $self;
} # new()
sub is_valid {
my ($self,$number) = @_;
if ($number =~ /^(\d{7})?(\d\d)$/i) {
return $2 eq $self->_compute_checkdigit($1);
}
return ''
} # is_valid()
sub complete {
my ($self,$number) = @_;
if ($number =~ /^(\d{7})$/i) {
return $number . $self->_compute_checkdigit($1);
}
return '';
} # complete()
sub basenumber {
my ($self,$number) = @_;
if ($number =~ /^(\d{7})(\d\d)$/i) {
return $1 if ($2 eq $self->_compute_checkdigit($1));
}
return '';
} # basenumber()
sub checkdigit {
my ($self,$number) = @_;
if ($number =~ /^(\d{7})(\d\d)$/i) {
return $2 if (uc($2) eq $self->_compute_checkdigit($1));
}
return '';
} # checkdigit()
sub _compute_checkdigit {
my $self = shift;
my $number = shift;
if ($number =~ /^\d{7}$/i) {
return sprintf("%2.2d",97 - ($number % 97));
}
return -1;
} # _compute_checkdigit()
# Preloaded methods go here.
1;
__END__
=head1 NAME
CheckDigits::M97_001 - compute check digits for VAT Registration Number (BE)
=head1 SYNOPSIS
use Algorithm::CheckDigits;
$ustid = CheckDigits('ustid_be');
if ($ustid->is_valid('136695962')) {
# do something
}
$cn = $ustid->complete('1366959');
# $cn = '136695962'
$cd = $ustid->checkdigit('136695962');
# $cd = '62'
$bn = $ustid->basenumber('136695962');
# $bn = '1366959'
=head1 DESCRIPTION
=head2 ALGORITHM
=over 4
=item 1
The whole number (without checksum) is taken modulo 97.
=item 2
The checksum is difference of the remainder from step 1 to 97.
=back
=head2 METHODS
=over 4
=item is_valid($number)
Returns true only if C<$number> consists solely of numbers and the last digit
is a valid check digit according to the algorithm given above.
Returns false otherwise,
=item complete($number)
The check digit for C<$number> is computed and concatenated to the end
of C<$number>.
Returns the complete number with check digit or '' if C<$number>
does not consist solely of digits and spaces.
=item basenumber($number)
Returns the basenumber of C<$number> if C<$number> has a valid check
digit.
Return '' otherwise.
=item checkdigit($number)
Returns the checkdigits of C<$number> if C<$number> has a valid check
digit.
Return '' otherwise.
=back
=head2 EXPORT
None by default.
=head1 AUTHOR
Mathias Weidner, C<< <mamawe@cpan.org> >>
=head1 SEE ALSO
L<perl>,
L<CheckDigits>,
F<www.pruefziffernberechnung.de>.
=cut