package Enigmatic::Rotor;
use DAKKAR::p 'class';
use Enigmatic::Types qw(WiringMap Letter RotorPos);

has wiring => (
    is => 'ro',
    isa => WiringMap,
    coerce => 1,
);

has ring_setting => (
    is => 'rw',
    isa => RotorPos,
    default => 0,
);

around BUILDARGS => sub {
    my $orig  = shift;
    my $class = shift;

    if ( @_ == 1 && !ref $_[0] ) {
        return $class->$orig( wiring => $_[0] );
    }
    else {
        return $class->$orig(@_);
    }
};

sub map {
    my $self = shift;
    my ($letter) = pos_validated_list(
        \@_,
        { isa => Letter },
    );

    return $self->wiring->at($self->_apply_ring_setting($letter));
}

sub _apply_ring_setting {
    my $self = shift;
    my ($letter) = pos_validated_list(
        \@_,
        { isa => Letter },
    );

    return chr(
        (ord($letter) - ord('A') + $self->ring_setting)
            % 26
                +ord('A') );
}