# Copyright (C) 2010, Sascha Kiefer.

package Class::Properties;
use strict;
use warnings;

require Carp;

sub new {
    my $proto = shift;
    my $class = ref $proto || $proto;

    return bless exists $_[0] ? exists $_[1] ? {@_} : { %{ $_[0] } } : {},
      $class;
}

sub property {
    my $class = shift;

    my ( $idx, $len ) = ( 0, scalar @_ );
    while ( $idx < $len ) {

        my $key = $_[ $idx++ ];
        my $val = $idx < $len ? $_[ $idx++ ] : undef;

        my @names = ref $key eq 'ARRAY' ? @$key : ($key);
        foreach my $name (@names) {
            Carp::croak(qq/Property "$name" is invalid./)
              unless $name =~ /^[a-zA-Z_]\w*$/;

            no strict 'refs';
            *{"${class}::$name"} = sub {
                my $self = shift;
                if (@_) {
                    $self->{$name} = @_ == 1 ? $_[0] : [@_];
                    return $self;
                }
                else {
                    $self->{$name} = $val
                      unless exists $self->{$name};
                    return $self->{$name};
                }
            };
        }
    }
}

1;