package MusicBrainz::Server::Data::Role::NewFromRow;
use Moose::Role;
use Class::Load qw( load_class );
use namespace::autoclean;

sub _entity_class
{
    die("Not implemented");
}

sub _column_mapping
{
    return {};
}

sub _new_from_row
{
    my ($self, $row, $prefix) = @_;
    return unless $row;
    my %info;
    my %mapping = %{$self->_column_mapping};
    my @attribs = %mapping ? keys %mapping : keys %{$row};
    $prefix ||= '';
    foreach my $attrib (@attribs) {
        my $column = $mapping{$attrib} || $attrib;
        my $val;
        if (ref($column) eq 'CODE') {
            $val = $column->($row, $prefix);
        }
        elsif (defined $row->{$prefix.$column}) {
            $val = $row->{$prefix.$column};
        }
        $info{$attrib} = $val if defined $val;
    }
    my $entity_class = $self->_entity_class($row);
    load_class($entity_class);
    return $entity_class->new(%info);
}

1;