package Gorgon;
use 5.6.1;
use Exporter qw(import);
use strict;
no strict qw(subs);
use warnings;

use vars qw($VERSION);
$VERSION = '2.00';

use constant Earth => 0x0001;
use constant Air => 0x0002;
use constant Fire => 0x0004;
use constant Water => 0x0008;

our %elmt_name = (
    (Earth, "Earth"), (Air, "Air"),
    (Fire, "Fire"), (Water, "Water"),
);

sub new
{
    my $class = shift;
    my $self = {};

    $class = "Gorgon::Euryale" if ($class eq "Gorgon");
    bless($self, $class);
    return $self->_setup();
}

sub element
{
    my $self = shift;
    $self->{element} = $_ if (scalar @_ > 0);
    return $elmt_name{ $self->{element} };
}

package Gorgon::Euryale;
use strict;
no strict qw(subs);
use warnings;
use base qw(Gorgon);

sub _setup
{
    my $self = shift;
    $self->{element} = Water;
    return $self
}

sub transmute
{
    my $self = shift;
    my $elmt = $self->{element};

    if ($elmt ==  Water ) {$elmt =  Earth ;}
    else {$elmt <<= 1;}

    $self->{element} = $elmt;
    return $elmt;
}


package Gorgon::Stheno;
use strict;
no strict qw(subs);
use warnings;
use base qw(Gorgon);

sub _setup
{
    my $self = shift;
    $self->{element} = Earth;
    return $self
}

sub transmute
{
    my $self = shift;
    my $elmt = $self->{element};

    if ($elmt ==  Earth) {$elmt = Water;}
    else {$elmt >>= 1;}

    $self->{element} = $elmt;
    return $elmt;
}
1;