/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.event.internal;

import java.io.Serializable;

import org.hibernate.HibernateException;
import org.hibernate.collection.spi.PersistentCollection;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.event.spi.EventSource;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.type.CollectionType;

When a transient entity is passed to lock(), we must inspect all its collections and
1. associate any uninitialized PersistentCollections with this session
2. associate any initialized PersistentCollections with this session, using the
existing snapshot
3. throw an exception for each "new" collection
Author:
Gavin King/**
 * When a transient entity is passed to lock(), we must inspect all its collections and
 * 1. associate any uninitialized PersistentCollections with this session
 * 2. associate any initialized PersistentCollections with this session, using the
 * existing snapshot
 * 3. throw an exception for each "new" collection
 *
 * @author Gavin King
 */
public class OnLockVisitor extends ReattachVisitor {

	public OnLockVisitor(EventSource session, Serializable key, Object owner) {
		super( session, key, owner );
	}

	@Override
	public Object processCollection(Object collection, CollectionType type) throws HibernateException {
		if ( collection == null ) {
			return null;
		}

		final SessionImplementor session = getSession();
		final CollectionPersister persister = session.getFactory().getCollectionPersister( type.getRole() );

		if ( collection instanceof PersistentCollection ) {
			final PersistentCollection persistentCollection = (PersistentCollection) collection;
			if ( persistentCollection.setCurrentSession( session ) ) {
				if ( isOwnerUnchanged( persistentCollection, persister, extractCollectionKeyFromOwner( persister ) ) ) {
					// a "detached" collection that originally belonged to the same entity
					if ( persistentCollection.isDirty() ) {
						throw new HibernateException( "reassociated object has dirty collection" );
					}
					reattachCollection( persistentCollection, type );
				}
				else {
					// a "detached" collection that belonged to a different entity
					throw new HibernateException( "reassociated object has dirty collection reference" );
				}
			}
			else {
				// a collection loaded in the current session
				// can not possibly be the collection belonging
				// to the entity passed to update()
				throw new HibernateException( "reassociated object has dirty collection reference" );
			}
		}
		else {
			// brand new collection
			//TODO: or an array!! we can't lock objects with arrays now??
			throw new HibernateException( "reassociated object has dirty collection reference (or an array)" );
		}

		return null;
	}

}