package IMPL::ORM;
use strict;
use warnings;

use base qw(IMPL::Object);
use IMPL::Class::Property;
use Scalar::Util qw(weaken refaddr);

use IMPL::Exception;

our $Depth = 1; # çàãðóæàòü îáúåêò + 1 óðîâåíü äåòåé
our $UseProxy = 1;

BEGIN {
    private property _ObjectCache => prop_all;
    private property _MapInstances => prop_all;
    private property _WorkUnit => prop_all;
    public property Schema => prop_all;
}

sub ObjectInfoById {
    my ($this,$oid) = @_;
    
    return $this->_ObjectCache->{$oid};
}

sub ObjectInfo {
    my ($this,$inst) = @_;
    
    die new IMPL::InvalidOperationException("This method can be used only for a reference") unless ref $inst;
    
    return $this->_MapInstances->{refaddr $inst};
}


1;
__END__
=pod
=head1 SYNOPSIS

use IMPL::ORM::Sql;

my $DB = new IMPL::ORM::Sql("connection string");

local $IMPL::ORM::Depth = 1; # load childs only, no more

my $artist = $DB->Lookup( Artist => { name => 'Beatles' } );

my $order = new Order();
$order->AddItem($_) foreach $artist->Albums->List;

$DB->Save($order);

my $label = $artist->Albums->Index(0)->Label;

$DB->Populate($label); #load $label

=head1 DESCRIPTION
=head2 MEMBERS
=level 4
=back
=head2 Variables
=head2 INTERNALS
=head3 Object Representation

Êàæäûé êëàññ îòîáðàæàåìûé â èñòî÷íèê äàííûõ ïðåäñòàâëÿåòñÿ â âèäå íàáîðà
ñóùíîñòåé, êàæäàÿ èç êîòîðûõ ïðåäñòàâëÿåò ñîñòîÿíèå áàçîâîãî êëàññà.

Foo         entityFoo
    Bar         entityBar
    Baz         entityBaz

Ïðè ñîõðàíåíèè âèðòóàëüíûõ ñâîéñòâ êëàññîâ â ñîîòâåòñòâóþùèõ ñóùíîñòÿõ çàâîäèòñÿ
äâà ïîëÿ - îäíî ïîä ñîõðàíåíèå ñîáñòâåííîãî çíà÷åíèÿ ñâîéñòâà, äðóãîå - äëÿ
õðåíåèÿ âèðòóàëüíîãî çíà÷åíèÿ.

Foo
    public virtual property Name => prop_all, {Type => String};
    
entityFoo
    string m_Name - ñîáñòâåííîå çíà÷åíèå
    string v_Name - âðòóàëüíîå çíà÷åíèå
    
Êàæäûé ñîõðàíåííûé îáúåêò â áàçå èìååò ñîáñòâåííûé èäåíòèôèêàòîð.
Íîâûå îáúåêòû èäåíòèôèêàòîðà íå èìåþò, äî òåõ ïîð ïîêà îíè íå áóäóò ñîõðàíåíû.

=head3 Object Cache

Äëÿ ó÷åòà îáúåêòîâ, êîòîðûå ïðèñóòñòâóþò â èñòî÷íèêå äàííûõ èñïîëüçóåòñÿ êåø
îáúåêòîâ. Ñþäà ïîïàäàþò ïîëó÷åííûå èç áàçû îáúåêòû, à òàêæå âíîâü äîáàâëåííûå
îáúåêòû.

ObjectInfo => {
    instance => weak ref
    _id => data source dependent id
    state => {persistent|null|new|deleted}
    work_unit => ref to the work unit where object is acting
}

äàííàÿ ñòðóêòóðà äîñòóïíà ÷åðåç äâå ôóíêöèè ObjectInfoById è ObjectInfo

=head3 Type mapping

Èñòî÷íèê äàííûõ èìååò â ñåáå ñõåìó äàííûõ, êîòîðàÿ îïðåäåëÿåò íàáîð òèïîâ,
õðàíèìûõ â äàííîì èñòî÷íèêå. Åñòü íåñêîëüêî âèäîâ îòîáðàæåíèÿ òèïîâ:

=level 4

=item 1

Îòîáðàæåíèå êëàññîâ, êîãäà êëàññ ðàññìàðèâàåòñÿ â èäå íàáîðà ñâîéñòâ

=item

Îòîáðàæåíèå êëàññîâ â îäíî çíà÷åíèå (íàïðìåð ñòðîêó, äàííûå è ò.ï.)

=item

Êëàññû, êîòîðûå íà ïðÿìóþ ðàáîòàþò ñ èñòî÷íèêîì äàííûõ, òàêèå êàê êîëëåêöèè.

=back

=cut