EDIT

/**

* 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.monitor.IProgressMonitor;

import eu.etaxonomy.cdm.database.ICdmDataSource;

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

/**

 * Common updater base class for updating schema or terms.

 *

 * @see CdmUpdater

 * @see ISchemaUpdater

 * @see ITermUpdater

 *

 * @author a.mueller

 * @date 16.11.2010

 *

 */

public abstract class UpdaterBase<T extends ISchemaUpdaterStep, U extends IUpdater<U>> implements IUpdater<U> {

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

	protected List<T> list;

	protected String startVersion;

	protected String targetVersion;

	protected abstract boolean updateVersion(ICdmDataSource datasource, IProgressMonitor monitor, CaseType caseType) throws SQLException;

	protected abstract String getCurrentVersion(ICdmDataSource datasource, IProgressMonitor monitor, CaseType caseType) throws SQLException;

	@Override

	public int countSteps(ICdmDataSource datasource, IProgressMonitor monitor, CaseType caseType){

		int result = 0;

		//TODO test if previous updater is needed

		if (isToBeInvoked(datasource, monitor, caseType)){

			for (T step: list){

				result++; //+= list.size();

				result += step.getInnerSteps().size();

			}

			if (getPreviousUpdater() != null){

				result += getPreviousUpdater().countSteps(datasource, monitor, caseType);

			}

		}

		return result;

	}

	private boolean isToBeInvoked(ICdmDataSource datasource, IProgressMonitor monitor, CaseType caseType) {

		boolean result = true;

		String datasourceVersion;

		try {

			datasourceVersion = getCurrentVersion(datasource, monitor, caseType);

		} catch (SQLException e1) {

			monitor.warning("SQLException", e1);

			return false;

		}

		boolean isAfterMyStartVersion = isAfterMyStartVersion(datasourceVersion, monitor);

		boolean isBeforeMyStartVersion = isBeforeMyStartVersion(datasourceVersion, monitor);

//		boolean isBeforeMyTargetVersion = isBeforeMyTargetVersion(targetVersion, monitor);

		boolean isBeforeMyTargetVersion = isBeforeMyTargetVersion(targetVersion, monitor);

		boolean isDatasourceBeforeMyTargetVersion = isBeforeMyTargetVersion(datasourceVersion, monitor);

		result &= isDatasourceBeforeMyTargetVersion;

		result &= !(isAfterMyStartVersion && isBeforeMyTargetVersion);

		result &= ! (isBeforeMyStartVersion && getPreviousUpdater() == null);

		result &= !isBeforeMyTargetVersion;

		return result;

	}

	@Override

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

		String currentLibrarySchemaVersion = CdmMetaData.getDbSchemaVersion();

		return invoke(currentLibrarySchemaVersion, datasource, monitor, caseType);

	}

	@Override

	public boolean invoke(String targetVersion, ICdmDataSource datasource, IProgressMonitor monitor, CaseType caseType) throws Exception{

		boolean result = true;

		String datasourceVersion;

		try {

			datasourceVersion = getCurrentVersion(datasource, monitor, caseType);

		} catch (SQLException e1) {

			monitor.warning("SQLException", e1);

			return false;

		}

		boolean isAfterMyStartVersion = isAfterMyStartVersion(datasourceVersion, monitor);

		boolean isBeforeMyStartVersion = isBeforeMyStartVersion(datasourceVersion, monitor);

//		boolean isAfterMyTargetVersion = isAfterMyTargetVersion(targetVersion, monitor);

		boolean isBeforeMyTargetVersion = isBeforeMyTargetVersion(targetVersion, monitor);

		boolean isDatasourceBeforeMyTargetVersion = isBeforeMyTargetVersion(datasourceVersion, monitor);

		if (! isDatasourceBeforeMyTargetVersion){

			String warning = "Target version ("+targetVersion+") is not before updater target version ("+this.targetVersion+"). Nothing to update.";

			monitor.warning(warning);

			return true;

		}

		if (isAfterMyStartVersion && isBeforeMyTargetVersion){

			String warning = "Database version is higher than updater start version but lower than updater target version";

			RuntimeException exeption = new RuntimeException(warning);

			monitor.warning(warning, exeption);

			throw exeption;

		}

		if (isBeforeMyStartVersion){

			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(startVersion, datasource, monitor, caseType);

		}

		if (isBeforeMyTargetVersion){

			String warning = "Target version ("+targetVersion+") is lower than updater target version ("+this.targetVersion+")";

			RuntimeException exeption = new RuntimeException(warning);

			monitor.warning(warning, exeption);

			throw exeption;

		}

		if (result == false){

			return result;

		}

//		datasource.startTransaction();  transaction already started by CdmUpdater

		try {

			for (T step : list){

				result &= handleSingleStep(datasource, monitor, result, step, false, caseType);

				if (result == false){

					break;

				}

			}

			if (result == true){

				result &= updateVersion(datasource, monitor, caseType);

			}else{

				datasource.rollback();

			}

		} catch (Exception e) {

			datasource.rollback();

			logger.error("Error occurred while trying to run updater: " + this.getClass().getName());

			result = false;

		}

		return result;

	}

//	protected abstract boolean handleSingleStep(ICdmDataSource datasource,	IProgressMonitor monitor, boolean result, ISchemaUpdaterStep step, boolean isInnerStep) throws Exception;

	protected boolean handleSingleStep(ICdmDataSource datasource, IProgressMonitor monitor, boolean result, ISchemaUpdaterStep step, boolean isInnerStep, CaseType caseType)

			throws Exception {

		try {

			monitor.subTask(step.getStepName());

			Integer invokeResult = step.invoke(datasource, monitor, caseType);

			result &= (invokeResult != null);

			for (ISchemaUpdaterStep innerStep : step.getInnerSteps()){

				result &= handleSingleStep(datasource, monitor, result, innerStep, true, caseType);

				if (!result){

				    break;

				}

			}

//			if (! isInnerStep){

				monitor.worked(1);

//			}

		} catch (Exception e) {

			monitor.warning("Monitor: Exception occurred while handling single schema updating step", e);

			datasource.rollback();

			result = false;

		}

		return result;

	}

	protected boolean isAfterMyStartVersion(String dataSourceSchemaVersion, IProgressMonitor monitor) {

		int depth = 4;

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

		return compareResult > 0;

	}

	protected boolean isBeforeMyStartVersion(String dataSourceSchemaVersion, IProgressMonitor monitor) {

		int depth = 4;

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

		return compareResult < 0;

	}

	protected boolean isAfterMyTargetVersion(String dataSourceSchemaVersion, IProgressMonitor monitor) {

		int depth = 4;

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

		return compareResult > 0;

	}

	protected boolean isBeforeMyTargetVersion(String dataSourceSchemaVersion, IProgressMonitor monitor) {

		int depth = 4;

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

		return compareResult < 0;

	}

	@Override

	public abstract U getNextUpdater();

	@Override

	public abstract U getPreviousUpdater();

	/**

	 * @return

	 */

	public String getTargetVersion() {

		return this.targetVersion;

	}

}