#! /usr/bin/perl

use strict;
use warnings;

package Class::InsideOut;
use Attribute::Handlers;
use NEXT;
use Scalar::Util 1.09 qw(blessed refaddr);
our $VERSION = 0.01;

sub self { refaddr shift };

my %Values;
    
sub Field : ATTR(HASH) {
    my ($class, $symbol, $hash) = @_;
    my $values = $Values{$class} ||= [];
    push @{$values}, $hash;
};
        
sub DESTROY {
    my $self = $_[0];
    my $id = $self->self;
    while ( my ($class, $values) = each %Values ) {
        delete $_->{$id} foreach (@$values);
    };
    $self->NEXT::DESTROY()
};


package Class::InsideOut::YAML;

sub yaml_dump {
    my $item = shift;
    my $class = ref $item;
    my $self_id = $item->self;
    my $inverted = {};
    while (my ($class, $values) = each %Values) {
        my $class_fields = $inverted->{$class} ||= [];
        foreach my $field (@$values) {
            push @$class_fields, $field->{$self_id};
        };
        delete $inverted->{$class} unless @$class_fields;
    };
    my $ynode = YAML::Node->new({}, "perl/$class");
    $ynode->{class} = $class;
    $ynode->{object} = bless Storable::dclone($item), 'Class::InsideOut::Frozen';
    $ynode->{inverted} = $inverted;
    return($ynode);
};

sub yaml_load {
    my $ynode = shift;  
    my $self = bless $ynode->{object}, $ynode->{class};
    my $inverted = $ynode->{inverted};
    my $self_id = $self->self;
    while (my ($class, $values) = each %$inverted) {
        my $i = 0;
        foreach my $value (@$values) {
            $Values{$class}->[$i++]->{$self_id} = $value;
        };
    };
    return(bless $self, $ynode->{class});
};


1;