EDIT

// $Id$

/**

* Copyright (C) 2009 EDIT

* European Distributed Institute of Taxonomy 

* http://www.e-taxonomy.eu

* 

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.database.update;

import java.sql.SQLException;

import java.util.List;

import org.apache.log4j.Logger;

import eu.etaxonomy.cdm.common.IProgressMonitor;

import eu.etaxonomy.cdm.database.ICdmDataSource;

import eu.etaxonomy.cdm.model.common.CdmMetaData;

/**

 * @author a.mueller

 * @date 10.09.2010

 *

 */

public abstract class SchemaUpdaterBase implements ISchemaUpdater {

	@SuppressWarnings("unused")

	private static final Logger logger = Logger.getLogger(SchemaUpdaterBase.class);

	private String mySchemaVersion;

	protected static boolean INCLUDE_AUDIT = true;

	private List<ISchemaUpdaterStep> list;

	protected SchemaUpdaterBase(String mySchemaVersion){

		this.mySchemaVersion = mySchemaVersion;

		list = getUpdaterList();

	}

	@Override

	public int countSteps(ICdmDataSource datasource){

		int result = 0;

		//TODO test if previous updater is needed

		if (getPreviousUpdater() != null){

			result += getPreviousUpdater().countSteps(datasource);

		}

		result += list.size();

		return result;

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.database.update.ICdmUpdater#invoke()

	 */

	@Override

	public boolean invoke(ICdmDataSource datasource, IProgressMonitor monitor) throws Exception{

		boolean result = true;

		String datasourceSchemaVersion;

		try {

			datasourceSchemaVersion = getCurrentVersion(datasource, monitor);

		} catch (SQLException e1) {

			monitor.warning("SQLException", e1);

			return false;

		}

		boolean isAfterMyVersion = isAfterMyVersion(datasourceSchemaVersion, monitor);

		if (isAfterMyVersion){

			String warning = "Database version is higher than updater version";

			RuntimeException exeption = new RuntimeException(warning);

			monitor.warning(warning, exeption);

			throw exeption;

		}

		boolean isBeforeMyVersion = isBeforeMyVersion(datasourceSchemaVersion, monitor);

		if (isBeforeMyVersion){

			if (getPreviousUpdater() == null){

				String warning = "Database version is before updater version but no previous version updater exists";

				RuntimeException exeption = new RuntimeException(warning);

				monitor.warning(warning, exeption);

				throw exeption;

			}

			result &= getPreviousUpdater().invoke(datasource, monitor);

		}

		for (ISchemaUpdaterStep step : list){

			try {

				monitor.subTask(step.getStepName());

				Integer termId = step.invoke(datasource, monitor);

				result &= (termId != null);

				monitor.worked(1);

			} catch (Exception e) {

				// TODO Auto-generated catch block

				monitor.warning("Exception occurred while updating schema", e);

				throw e;

			}

		}

		return result;

	}

	protected abstract List<ISchemaUpdaterStep> getUpdaterList();

	protected boolean isAfterMyVersion(String dataSourceSchemaVersion, IProgressMonitor monitor) {

		int depth = 4;

		int compareResult = CdmMetaData.compareVersion(dataSourceSchemaVersion, mySchemaVersion, depth, monitor);

		return compareResult > 0;

	}

	protected boolean isBeforeMyVersion(String dataSourceSchemaVersion, IProgressMonitor monitor) {

		int depth = 4;

		int compareResult = CdmMetaData.compareVersion(dataSourceSchemaVersion, mySchemaVersion, depth, monitor);

		return compareResult > 0;

	}

	protected String getCurrentVersion(ICdmDataSource datasource, IProgressMonitor monitor) throws SQLException {

		int intSchemaVersion = 0;

		String sqlSchemaVersion = "SELECT value FROM CdmMetaData WHERE propertyname = " +  intSchemaVersion;

		try {

			String value = (String)datasource.getSingleValue(sqlSchemaVersion);

			return value;

		} catch (SQLException e) {

			monitor.warning("Error when trying to receive schemaversion: ", e);

			throw e;

		}

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.database.update.ICdmUpdater#getNextUpdater()

	 */

	@Override

	public abstract ISchemaUpdater getNextUpdater();

	/* (non-Javadoc)

	 * @see eu.etaxonomy.cdm.database.update.ICdmUpdater#getPreviousUpdater()

	 */

	@Override

	public abstract ISchemaUpdater getPreviousUpdater();

}