EDIT

// $Id$

/**

* Copyright (C) 2007 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.model.common;

import java.util.ArrayList;

import java.util.Comparator;

import java.util.List;

import javax.persistence.Entity;

import org.apache.log4j.Logger;

import org.joda.time.DateTime;

import eu.etaxonomy.cdm.common.IProgressMonitor;

/**

 * @author a.mueller

 * @created 07.09.2009

 * @version 1.0

 */

@Entity

public class CdmMetaData extends CdmBase{

	private static final long serialVersionUID = -3033376680593279078L;

	@SuppressWarnings("unused")

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

	/* It is a little bit confusing that this specific information is located in

	 * a generic class for metadata. Think about moving the schema version 

	 *  

	 */

	/**

	 * The database schema version number.

	 * It is recommended to have the first two numbers equal to the CDM Library version number.

	 * But it is not obligatory as there may be cases when the library number changes but the

	 * schema version is not changing.

	 * The third should be incremented if the schema changes in a way that SCHEMA_VALIDATION.UPDATE

	 * will probably not work or will not be enough to transform old data into new data.

	 * The fourth number should be incremented when minor schema changes take place that can

	 * be handled by SCHEMA_VALIDATION.UPDATE

	 * The last number represents the date of change.

	 */

//	private static final String dbSchemaVersion = "3.0.0.1.201101050000";

	private static final String dbSchemaVersion = "3.0.1.0.201104190000";	

	/**

	 * @return a list of default metadata objects 

	 */

	public static final List<CdmMetaData> defaultMetaData(){

		List<CdmMetaData> result = new ArrayList<CdmMetaData>();

		// schema version

		result.add(new CdmMetaData(MetaDataPropertyName.DB_SCHEMA_VERSION, dbSchemaVersion));

		//term version

		result.add(new CdmMetaData(MetaDataPropertyName.TERMS_VERSION, termsVersion));

		// database create time

		result.add(new CdmMetaData(MetaDataPropertyName.DB_CREATE_DATE, new DateTime().toString()));

		return result;	

	}

	/**

	 * The version number for the terms loaded by the termloader (csv-files)

	 * It is recommended to have the first two numbers equal to the CDM Library version number.

	 * 

	 * But it is not obligatory as there may be cases when the library number changes but the

	 * schema version is not changing.

	 * 

	 * The third should be incremented if the terms change in a way that is not compatible

	 * to the previous version (e.g. by changing the type of a term)

	 * 

	 * The fourth number should be incremented when compatible term changes take place

	 * (e.g. when new terms were added)

	 * 

	 * The last number represents the date of change.

	 */

	private static final String termsVersion = "3.0.1.4.201105100000";

	public enum MetaDataPropertyName{

		DB_SCHEMA_VERSION,

		TERMS_VERSION,

 		DB_CREATE_DATE,

		DB_CREATE_NOTE;

		public String getSqlQuery(){

			return "SELECT value FROM CdmMetaData WHERE propertyname=" + this.ordinal();

		}

	}

	/* END OF CONFUSION */

	private MetaDataPropertyName propertyName;

	private String value;

	/**

	 * Method to retrieve a CDM Libraries meta data

	 * @return

	 */

	public static final List<CdmMetaData> propertyList(){

		List<CdmMetaData> result = new ArrayList<CdmMetaData>();

		result.add(new CdmMetaData(MetaDataPropertyName.DB_SCHEMA_VERSION, dbSchemaVersion));

		result.add(new CdmMetaData(MetaDataPropertyName.TERMS_VERSION, termsVersion));

		result.add(new CdmMetaData(MetaDataPropertyName.DB_CREATE_DATE, new DateTime().toString()));

		return result;

	}

//********************* Constructor *********************************************/	

	/**

	 * Simple constructor to be used by Spring

	 */

	protected CdmMetaData(){

		super();

	}

	public CdmMetaData(MetaDataPropertyName propertyName, String value) {

		super();

		this.propertyName = propertyName;

		this.value = value;

	}

//****************** instance methods ****************************************/	

	/**

	 * @return the propertyName

	 */

	public MetaDataPropertyName getPropertyName() {

		return propertyName;

	}

	/**

	 * @param propertyName the propertyName to set

	 */

	public void setPropertyName(MetaDataPropertyName propertyName) {

		this.propertyName = propertyName;

	}

	/**

	 * @return the value

	 */

	public String getValue() {

		return value;

	}

	/**

	 * @param value the value to set

	 */

	public void setValue(String value) {

		this.value = value;

	}

//******************** Version comparator **********************************/

	public static class VersionComparator implements Comparator<String>{

		Integer depth;

		IProgressMonitor monitor;

		public VersionComparator(Integer depth, IProgressMonitor monitor){

			this.depth = depth;

			this.monitor = monitor;

		}

		/* (non-Javadoc)

		 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)

		 */

		public int compare(String version1, String version2) {

			int result = 0;

			String[] version1Split = version1.split("\\.");

			String[] version2Split = version2.split("\\.");

			if(version1Split.length == 1 || version2Split.length == 1){

				throwException("Tried to compare version but given Strings don't seem to " +

						"contain version numbers. version1: " + version1 + ", version2:" + version2); 

			}

			if(depth != null && (version1Split.length < depth || version2Split.length < depth )){

				throwException("Desired depth can not be achieved with the given strings. depth: " + depth  + ", version1: " + version1 + ", version2:" + version2); 

			}			

			int length = (depth == null ||version1Split.length < depth) ? version1Split.length : depth;

			for (int i = 0; i < length; i++){

				Long version1Part = Long.valueOf(version1Split[i]);

				Long version2Part = Long.valueOf(version2Split[i]);

				int partCompare = version1Part.compareTo(version2Part);

				if (partCompare != 0){

					return partCompare;

				}

			}

			return result;

		}

		private Throwable throwException(String message){

			RuntimeException exception =  new RuntimeException(message);

			if (monitor != null){

				monitor.warning(message, exception);

			}

			throw exception;

		}

	}

	/**

	 * Compares two version string. If version1 is higher than version2 a positive result is returned.

	 * If both are equal 0 is returned, otherwise -1 is returned.

	 * @see Comparator#compare(Object, Object)

	 * @param version1

	 * @param version2

	 * @param depth

	 * @param monitor

	 * @return

	 */

	public static int compareVersion(String version1, String version2, Integer depth, IProgressMonitor monitor){

		VersionComparator versionComparator = new VersionComparator(depth, monitor);

		return versionComparator.compare(version1, version2);

	}

	public static boolean isDbSchemaVersionCompatible(String version){

		return compareVersion(dbSchemaVersion, version, 3, null) == 0;

	}

	public static String getDbSchemaVersion() {

		return dbSchemaVersion;

	}

	public static String getTermsVersion() {

		return termsVersion;

	}

	public static boolean isTermsVersionCompatible(String version){

		return compareVersion(termsVersion, version, 3, null) == 0;

	}

}