/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, 2013, 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;

import org.hibernate.type.VersionType;

Represents a replication strategy.
Author:
Gavin King
See Also:
Session.replicate(Object, ReplicationMode)/**
 * Represents a replication strategy.
 *
 * @author Gavin King
 * @see Session#replicate(Object, ReplicationMode)
 */
public enum ReplicationMode {
	
Throw an exception when a row already exists.
/**
	 * Throw an exception when a row already exists.
	 */
	EXCEPTION {
		@Override
		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 replicated entities when a row already exists.
	 */
	IGNORE {
		@Override
		public boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType) {
			return false;
		}
	},
	
Overwrite existing rows when a row already exists.
/**
	 * Overwrite existing rows when a row already exists.
	 */
	OVERWRITE {
		@Override
		public boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType) {
			return true;
		}
	},
	
When a row already exists, choose the latest version.
/**
	 * When a row already exists, choose the latest version.
	 */
	LATEST_VERSION {
		@Override
		@SuppressWarnings("unchecked")
		public boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType) {
			// always overwrite non-versioned data (because we don't know which is newer)
			return versionType == null || versionType.getComparator().compare( currentVersion, newVersion ) <= 0;
		}
	};

	
Determine whether the mode dictates that the data being replicated should overwrite the data found.
Params:
entity – The entity being replicated
currentVersion – The version currently on the target database table.
newVersion – The replicating version
versionType – The version type
Returns:
true indicates the data should be overwritten; false indicates it should not./**
	 * Determine whether the mode dictates that the data being replicated should overwrite the data found.
	 *
	 * @param entity The entity being replicated
	 * @param currentVersion The version currently on the target database table.
	 * @param newVersion The replicating version
	 * @param versionType The version type
	 *
	 * @return {@code true} indicates the data should be overwritten; {@code false} indicates it should not.
	 */
	public abstract boolean shouldOverwriteCurrentVersion(Object entity, Object currentVersion, Object newVersion, VersionType versionType);

}