/*
 * 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.id.enhanced;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.hibernate.HibernateException;
import org.hibernate.dialect.Dialect;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.id.IdentifierGeneratorHelper;
import org.hibernate.id.IntegralDataTypeHolder;
import org.hibernate.internal.CoreMessageLogger;

import org.jboss.logging.Logger;

Describes a sequence.
Author:
Steve Ebersole/**
 * Describes a sequence.
 *
 * @author Steve Ebersole
 */
public class SequenceStructure implements DatabaseStructure {
	private static final CoreMessageLogger LOG = Logger.getMessageLogger(
			CoreMessageLogger.class,
			SequenceStructure.class.getName()
	);

	private final String sequenceName;
	private final int initialValue;
	private final int incrementSize;
	private final Class numberType;
	private final String sql;
	private boolean applyIncrementSizeToSourceValues;
	private int accessCounter;

	public SequenceStructure(
			Dialect dialect,
			String sequenceName,
			int initialValue,
			int incrementSize,
			Class numberType) {
		this.sequenceName = sequenceName;
		this.initialValue = initialValue;
		this.incrementSize = incrementSize;
		this.numberType = numberType;
		sql = dialect.getSequenceNextValString( sequenceName );
	}

	@Override
	public String getName() {
		return sequenceName;
	}

	@Override
	public int getIncrementSize() {
		return incrementSize;
	}

	@Override
	public int getTimesAccessed() {
		return accessCounter;
	}

	@Override
	public int getInitialValue() {
		return initialValue;
	}

	@Override
	public AccessCallback buildCallback(final SessionImplementor session) {
		return new AccessCallback() {
			@Override
			public IntegralDataTypeHolder getNextValue() {
				accessCounter++;
				try {
					final PreparedStatement st = session.getTransactionCoordinator().getJdbcCoordinator().getStatementPreparer().prepareStatement( sql );
					try {
						final ResultSet rs = session.getTransactionCoordinator().getJdbcCoordinator().getResultSetReturn().extract( st );
						try {
							rs.next();
							final IntegralDataTypeHolder value = IdentifierGeneratorHelper.getIntegralDataTypeHolder( numberType );
							value.initialize( rs, 1 );
							if ( LOG.isDebugEnabled() ) {
								LOG.debugf( "Sequence value obtained: %s", value.makeValue() );
							}
							return value;
						}
						finally {
							try {
								session.getTransactionCoordinator().getJdbcCoordinator().release( rs, st );
							}
							catch( Throwable ignore ) {
								// intentionally empty
							}
						}
					}
					finally {
						session.getTransactionCoordinator().getJdbcCoordinator().release( st );
					}

				}
				catch ( SQLException sqle) {
					throw session.getFactory().getSQLExceptionHelper().convert(
							sqle,
							"could not get next sequence value",
							sql
					);
				}
			}

			@Override
			public String getTenantIdentifier() {
				return session.getTenantIdentifier();
			}
		};
	}

	@Override
	public void prepare(Optimizer optimizer) {
		applyIncrementSizeToSourceValues = optimizer.applyIncrementSizeToSourceValues();
	}

	@Override
	public String[] sqlCreateStrings(Dialect dialect) throws HibernateException {
		final int sourceIncrementSize = applyIncrementSizeToSourceValues ? incrementSize : 1;
		return dialect.getCreateSequenceStrings( sequenceName, initialValue, sourceIncrementSize );
	}

	@Override
	public String[] sqlDropStrings(Dialect dialect) throws HibernateException {
		return dialect.getDropSequenceStrings( sequenceName );
	}

	@Override
	public boolean isPhysicalSequence() {
		return true;
	}
}