/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC 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 Middleware LLC.
 *
 * 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;

import org.hibernate.type.VersionType;

/**
 * Represents a replication strategy.
 *
 * @author Gavin King
 * @see Session#replicate(Object, ReplicationMode)
 */
public enum ReplicationMode {
	/**
	 * Throw an exception when a row already exists.
	 */
	EXCEPTION {
		public boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType) {
			throw new AssertionFailure( "should not be called" );
		}
	},
	/**
	 * Ignore replicated entities when a row already exists.
	 */
	IGNORE {
		public boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType) {
			return false;
		}
	},
	/**
	 * Overwrite existing rows when a row already exists.
	 */
	OVERWRITE {
		public boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType) {
			return true;
		}
	},
	/**
	 * When a row already exists, choose the latest version.
	 */
	LATEST_VERSION {
		public boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType) {
			if ( versionType == null ) {
				return true; //always overwrite nonversioned data
			}
			return versionType.getComparator().compare( currentVersion, newVersion ) <= 0;
		}
	};

	public abstract boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType);


}