/*
 * 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.event.spi.EventSource;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.type.CollectionType;

When an entity is passed to replicate(), and there is an existing row, 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. execute a collection removal (SQL DELETE) for each null collection property
or "new" collection
Author:
Gavin King/**
 * When an entity is passed to replicate(), and there is an existing row, 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. execute a collection removal (SQL DELETE) for each null collection property
 * or "new" collection
 *
 * @author Gavin King
 */
public class OnReplicateVisitor extends ReattachVisitor {

	private boolean isUpdate;

	OnReplicateVisitor(EventSource session, Serializable key, Object owner, boolean isUpdate) {
		super( session, key, owner );
		this.isUpdate = isUpdate;
	}

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

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

		if ( isUpdate ) {
			removeCollection( persister, extractCollectionKeyFromOwner( persister ), session );
		}
		if ( collection != null && collection instanceof PersistentCollection ) {
			final PersistentCollection wrapper = (PersistentCollection) collection;
			wrapper.setCurrentSession( session );
			if ( wrapper.wasInitialized() ) {
				session.getPersistenceContext().addNewCollection( persister, wrapper );
			}
			else {
				reattachCollection( wrapper, type );
			}
		}
		else {
			// otherwise a null or brand new collection
			// this will also (inefficiently) handle arrays, which
			// have no snapshot, so we can't do any better
			//processArrayOrNewCollection(collection, type);
		}

		return null;

	}

}