root/trunk/cdmlib/cdmlib-model/src/main/java/eu/etaxonomy/cdm/model/common/CdmMetaData.java

// $Id$
/**
* 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.monitor.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 = "3.0.1.5.201109280000";
        
        
        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;
        }
        
}