package Acme::Goedelize;

use strict;
use warnings;

use Carp;
use Math::BigInt;

require Exporter;

our @ISA = qw(Exporter);

our $VERSION = '0.02';


# Alpha-to-number
my %a_to_n = ( ' ' => '0',
               'a' => '1',
               'b' => '2',
               'c' => '3',
               'd' => '4',
               'e' => '5',
               'f' => '6',
               'g' => '7',
               'h' => '8',
               'i' => '9',
               'j' => '10',
               'k' => '11',
               'l' => '12',
               'm' => '13',
               'n' => '14',
               'o' => '15',
               'p' => '16',
               'q' => '17',
               'r' => '18',
               's' => '19',
               't' => '20',
               'u' => '21',
               'v' => '22',
               'w' => '23',
               'x' => '24',
               'y' => '25',
               'z' => '26',
               '.' => '27'
);

### Methods

sub new {
  bless {}, shift;
}

sub to_number {
  my ($self, $text) = @_;

  my %link = %a_to_n;
  
  ### Check the text
  croak "The string must contain only alpha chars and spaces"
    if ($text !~ /^[a-zA-Z\s]*$/); 
  
  ### Append dot
  if ($text !~ /\.$/) { $text .= "."; }

  my @txt = split(//, $text);

  my $current_prime = 2;
  my $result = Math::BigInt->new(1);

  foreach my $char ( @txt ) {
    my $prime = get_next_prime($current_prime);
    my $current = Math::BigInt->new($prime);
    $result *= ($current ** $link{$char});
    $current_prime = $prime + 1;
  }
  return $result;
}


sub to_text {
  my ($self, $number) = @_;

  my %link = reverse %a_to_n;
  
  ### Check the text
  croak "The string must be number\n"
    if $number !~ /^[0-9]*$/;

  my $goedel = Math::BigInt->new($number);

  my $current_prime = 2;
  my $result;
  
  PROCESS: while (1) {
    my $prime = get_next_prime($current_prime);
  
    my $times = 0;
    my $tmp = $goedel;
    DIVISION: while (1) {
      my $num = ($tmp/$prime);
      last DIVISION if ( ($tmp % $prime) > 0 );
      $times++; 
      $tmp = $num;
    }
    
    last PROCESS if $link{$times} eq ".";
    $result .= $link{$times};
    $current_prime = $prime + 1;
  }
  return $result;
}

sub get_next_prime {
  my $current = shift;
  GUESS: for (my $guess = $current; ; $guess++) 
  {
    for (my $divisor = 2; $divisor < $guess; $divisor++) 
    {
      next GUESS unless $guess % $divisor;
    }
    return $guess;
  }
}


1;
__END__


=head1 NAME

Acme::Goedelize - Goedelize text

=head1 SYNOPSIS

  use Acme::Goedelize;

  my $goedelize = new Acme::Goedelize;
  
  my $number = $goedelize->to_number('text');
  my $text   = $goedelize->to_text($number);

=head1 DESCRIPTION

Transforms text into one big number and vice versa.


=head1 AUTHOR

Todor Todorov, E<lt>acidmax@jambolnet.comE<gt>

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2004 by Todor Todorov

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.


=cut