/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
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 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().getMetamodel().collectionPersister( type.getRole() );

		if ( isUpdate ) {
			removeCollection( persister, extractCollectionKeyFromOwner( persister ), session );
		}
		if ( collection != null && collection instanceof PersistentCollection ) {
			final PersistentCollection wrapper = (PersistentCollection) collection;
			wrapper.setCurrentSession( (SessionImplementor) 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;

	}

}