package Data::MultiValued::TagContainer;
use Moose;
use Moose::Util::TypeConstraints;
use MooseX::Types::Moose qw(HashRef);
use Data::MultiValued::Exceptions;

has _storage => (
    is => 'rw',
    isa => HashRef,
    init_arg => undef,
    default => sub { { } },
    traits => ['Hash'],
    handles => {
        _has_tag => 'exists',
        _get_tag => 'get',
        _create_tag => 'set',
    },
);

has _default_tag => (
    is => 'rw',
    init_arg => undef,
    predicate => '_has_default_tag',
);

sub get {
    my ($self,$args) = @_;

    my $tag = $args->{tag};

    if (!defined($tag)) {
        if ($self->_has_default_tag) {
            return $self->_default_tag;
        }

        Data::MultiValued::Exceptions::TagNotFound->throw({
            value => $tag,
        });
    }

    if (!$self->_has_tag($tag)) {
        Data::MultiValued::Exceptions::TagNotFound->throw({
            value => $tag,
        });
    }
    return $self->_get_tag($tag);
}

sub get_or_create {
    my ($self,$args) = @_;

    my $tag = $args->{tag};

    if (!defined($tag)) {
        if ($self->_has_default_tag) {
            return $self->_default_tag;
        }
        else {
            return $self->_default_tag(
                $self->_create_new_inferior
            );
        }
    }

    if (!$self->_has_tag($tag)) {
        $self->_create_tag($tag,$self->_create_new_inferior);
    }
    return $self->_get_tag($tag);
}

sub _create_new_inferior {
    my ($self) = @_;
    return {};
}

1;