/*
 * 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.envers.internal.synchronization;

import java.io.Serializable;

import org.hibernate.Session;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.envers.internal.revisioninfo.RevisionInfoGenerator;
import org.hibernate.envers.internal.synchronization.work.AuditWorkUnit;
import org.hibernate.envers.internal.synchronization.work.PersistentCollectionChangeWorkUnit;
import org.hibernate.envers.internal.tools.EntityTools;

/**
 * Notifies {@link RevisionInfoGenerator} about changes made in the current revision.
 *
 * @author Lukasz Antoniak (lukasz dot antoniak at gmail dot com)
 */
public class EntityChangeNotifier {
	private final RevisionInfoGenerator revisionInfoGenerator;
	private final SessionImplementor sessionImplementor;

	public EntityChangeNotifier(RevisionInfoGenerator revisionInfoGenerator, SessionImplementor sessionImplementor) {
		this.revisionInfoGenerator = revisionInfoGenerator;
		this.sessionImplementor = sessionImplementor;
	}

	/**
	 * Notifies {@link RevisionInfoGenerator} about changes made in the current revision. Provides information
	 * about modified entity class, entity name and its id, as well as {@link org.hibernate.envers.RevisionType}
	 * and revision log entity.
	 *
	 * @param session Active session.
	 * @param currentRevisionData Revision log entity.
	 * @param vwu Performed work unit.
	 */
	public void entityChanged(Session session, Object currentRevisionData, AuditWorkUnit vwu) {
		Serializable entityId = vwu.getEntityId();
		if ( entityId instanceof PersistentCollectionChangeWorkUnit.PersistentCollectionChangeWorkUnitId ) {
			// Notify about a change in collection owner entity.
			entityId = ( (PersistentCollectionChangeWorkUnit.PersistentCollectionChangeWorkUnitId) entityId ).getOwnerId();
		}
		final Class entityClass = EntityTools.getEntityClass( sessionImplementor, vwu.getEntityName() );
		revisionInfoGenerator.entityChanged(
				entityClass,
				vwu.getEntityName(),
				entityId,
				vwu.getRevisionType(),
				currentRevisionData
		);
	}
}