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.

 *

 * Note: prior to v4.8 this was a common base class for {@link SchemaUpdaterBase}

 * and term updater. Since v4.8 we do not have a term updater anymore.

 * Therefore in future this class could be merged with {@link SchemaUpdaterBase}

 *

 * @see CdmUpdater

 * @see ISchemaUpdater

 *

 * @author a.mueller

 * @since 16.11.2010

 *

 */

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

            implements IUpdater<U> {

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

	protected List<T> list;

	protected String startVersion;

	protected String targetVersion;

	protected abstract void updateVersion(ICdmDataSource datasource, IProgressMonitor monitor,

	        CaseType caseType, SchemaUpdateResult result) 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 void invoke(ICdmDataSource datasource, IProgressMonitor monitor,

	        CaseType caseType, SchemaUpdateResult result) throws Exception{

		String currentLibrarySchemaVersion = CdmMetaData.getDbSchemaVersion();

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

	}

	@Override

	public void invoke(String targetVersion, ICdmDataSource datasource,

	        IProgressMonitor monitor, CaseType caseType, SchemaUpdateResult result) throws Exception{

	    String datasourceVersion;

		try {

			datasourceVersion = getCurrentVersion(datasource, monitor, caseType);

		} catch (SQLException e1) {

		    String message = "SQLException";

			monitor.warning(message, e1);

			result.addException(e1, message, "UpdaterBase.invoke");

			return;

		}

		if (isBefore4_0_0(datasourceVersion, monitor, result)){

		    return;

		}

		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);

			result.addWarning(warning);

			return;

		}

		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;

			}

			getPreviousUpdater().invoke(startVersion, datasource, monitor, caseType, result);

		}

		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.isSuccess()){

			return;

		}

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

		try {

			for (T step : list){

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

				if (!result.isSuccess()){

					break;

				}

			}

			if (result.isSuccess()){

				updateVersion(datasource, monitor, caseType, result);

			}else{

				datasource.rollback();

			}

		} catch (Exception e) {

			datasource.rollback();

			String message = "Error occurred while trying to run updater: " + this.getClass().getName();

			logger.error(message);

			result.addException(e, message, "UpdaterBase.invoke");

		}

		return;

	}

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

			throws Exception {

		try {

			monitor.subTask(step.getStepName());

			step.invoke(datasource, monitor, caseType, result);

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

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

				if (!result.isSuccess()){

				    break;

				}

			}

//			if (! isInnerStep){

			monitor.worked(1);

//			}

		} catch (Exception e) {

		    String message = "Monitor: Exception occurred while handling single schema updating step";

			monitor.warning(message, e);

			datasource.rollback();

			result.addException(e, message, "handleSingleStep:" + step.getStepName());

		}

		return;

	}

	   /**

     * @param datasourceVersion

     * @param monitor

     * @param result

     * @return

     */

    private boolean isBefore4_0_0(String datasourceVersion, IProgressMonitor monitor, SchemaUpdateResult result) {

        if (CdmMetaData.compareVersion(datasourceVersion, "4.0.0.0", 3, monitor) < 0){

            String message = "Schema version of the database is prior to version 4.0.0.\n"

                    + "Versions prior to 4.0.0 need to be updated by an EDIT Platform between 4.0 and 4.7 (including both).\n"

                    + "Please update first to version 4.0.0 (or higher) before updating to the current version.";

            result.addError(message, "CdmUpdater.updateToCurrentVersion");

            return true;

        }

        return false;

    }

	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;

	}

}