/*
 * The contents of this file are subject to the terms 
 * of the Common Development and Distribution License 
 * (the "License").  You may not use this file except 
 * in compliance with the License.
 * 
 * You can obtain a copy of the license at 
 * glassfish/bootstrap/legal/CDDLv1.0.txt or 
 * https://glassfish.dev.java.net/public/CDDLv1.0.html. 
 * See the License for the specific language governing 
 * permissions and limitations under the License.
 * 
 * When distributing Covered Code, include this CDDL 
 * HEADER in each file and include the License file at 
 * glassfish/bootstrap/legal/CDDLv1.0.txt.  If applicable, 
 * add the following below this CDDL HEADER, with the 
 * fields enclosed by brackets "[]" replaced with your 
 * own identifying information: Portions Copyright [yyyy] 
 * [name of copyright owner]
 */
// Copyright (c) 1998, 2005, Oracle. All rights reserved.  
package oracle.toplink.essentials.ejb.cmp3;

import java.lang.instrument.ClassFileTransformer;
import java.io.File;
import java.util.Map;
import java.util.Collection;
import java.util.Iterator;
import java.util.Vector;
import java.util.HashMap;
import java.net.URL;
import javax.persistence.*;
import javax.persistence.spi.*;
import oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerFactoryImpl;
import oracle.toplink.essentials.internal.ejb.cmp3.JavaSECMPInitializer;
import oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl;
import oracle.toplink.essentials.ejb.cmp3.persistence.PersistenceUnitProcessor;
import oracle.toplink.essentials.threetier.ServerSession;
import oracle.toplink.essentials.logging.AbstractSessionLog;
import oracle.toplink.essentials.logging.SessionLog;

import java.util.Properties; 
import oracle.toplink.essentials.tools.schemaframework.SchemaManager;

/**
 * This is the TopLink EJB 3.0 provider
 * The default constructor can be used to build the provider by reflection, after which it can
 * be used to create EntityManagerFactories
 */

public class EntityManagerFactoryProvider implements javax.persistence.spi.PersistenceProvider {

    // The following constants are used in persistence xml to specify properties
    public static final String JDBC_DRIVER_PROPERTY = "jdbc.driver";
    public static final String JDBC_CONNECTION_STRING_PROPERTY = "jdbc.connection.string";
    public static final String JDBC_USER_PROPERTY = "jdbc.user";
    public static final String JDBC_PASSWORD_PROPERTY = "jdbc.password";
    public static final String TOPLINK_PLATFORM_PROPERTY = "toplink.platform.class.name";
    public static final String TOPLINK_SERVER_PLATFORM_PROPERTY = "toplink.server.platform.class.name";
    public static final String TOPLINK_EXTERNAL_TRANSACTION_CONTROLLER_PROPERTY = "toplink.external.transaction.controller.class.name";
    public static final String TOPLINK_LOGGING_LEVEL = "toplink.logging.level";
    public static final String TOPLINK_ORM_THROW_EXCEPTIONS = "toplink.orm.throw.exceptions";
    private static final String TOPLINK_VALIDATION_ONLY_PROPERTY = "oracle.toplink.essentials.ValidationOnly";

    public static final String DDL_GENERATION   = "ddl-generation";
    public static final String CREATE_ONLY      = "createtables";
    public static final String DROP_AND_CREATE  = "dropandcreate";
    public static final String NONE             = "none";
    public static final String APP_LOCATION     = "application-location";
    public static final String CREATE_JDBC_DDL_FILE = "create-ddl-jdbc-file-name";
    public static final String DROP_JDBC_DDL_FILE   = "drop-ddl-jdbc-file-name";
    
    public static final String DEFAULT_APP_LOCATION = "." + File.separator;
     public static final String DEFAULT_CREATE_JDBC_FILE_NAME = "createDDL.jdbc";
     public static final String DEFAULT_DROP_JDBC_FILE_NAME = "dropDDL.jdbc";
     public static final String JAVASE_DB_INTERACTION = "INTERACT_WITH_DB";

    // Store previously created application entity manager factories here.  For an application based
    // provider, only one factory will exist for each name
    public HashMap<String, EntityManagerFactory> applicationEntityManagerFactories = null;

    /**
     * A default constructor is required by all Providers accoring the the EJB 3.0 specification
     */
    public EntityManagerFactoryProvider() {
        applicationEntityManagerFactories = new HashMap();        
    }

    /**
	 * This is the method that will be used by javax.persistence.Persistence to get an
     * EntityManagerFactory.  javax.persistence.Persistence is used by J2SE EJB 3.0 users
     * @see {@link Persistence#createEntityManagerFactory()}.
	 */
	public EntityManagerFactory createEntityManagerFactory(String emName, Map m){
        String name = emName;
        if (name == null){
            name = "";
        }
        EntityManagerFactory emf = applicationEntityManagerFactories.get(name);
        if (emf != null){
            return emf;
        }
        ServerSession session = getServerSession(name, m);
        if (session != null){
            emf = new EntityManagerFactoryImpl(session);
            session.login(); //PG->
            generateDDLFiles(session, getPersistenceUnitProperties(name, m), true); //PG->
            return emf;
        }
        return null;
    }

  /**
   * This method should be called by containers that wish to integrate with TopLink's
   * EJB 3.0 provider.
   * In order to use TopLink's weaving capabilities to allow lazy loading and change 
   * tracking
   * @param info 
   * @return 
   */
    public EntityManagerFactory createContainerEntityManagerFactory(PersistenceUnitInfo info){
        EntityManagerSetupImpl emSetupImpl = new EntityManagerSetupImpl();
        ClassLoader tempLoader = info.getTempClassLoader();
        Collection entities = buildEntityList(info, tempLoader);
        ClassFileTransformer transformer = emSetupImpl.predeploy(entities, tempLoader, info);
        if (transformer != null){
            info.addTransformer(transformer);
        }
        ClassLoader realLoader = info.getClassLoader();
        entities = buildEntityList(info, realLoader);
        ServerSession session = emSetupImpl.deploy(entities, realLoader);
        boolean validationOnly = info.getProperties().getProperty(
                TOPLINK_VALIDATION_ONLY_PROPERTY, "false").
                equalsIgnoreCase("true");
        if(validationOnly) {
            session.initializeDescriptors();
        } else {
            session.login();
            generateDDLFiles(session, info.getProperties(), false);
        }
        return new EntityManagerFactoryImpl(session);
    }

    private void generateDDLFiles(ServerSession session, Properties props, 
            boolean inSEmode) {
        boolean createTables = false, shouldDropFirst = false;
        String appLocation; 
        String createDDLJdbc;
        String dropDDLJdbc;
        String ddlGeneration = NONE;
        
        if(null == props)
            return;

        ddlGeneration = props.getProperty(DDL_GENERATION, NONE);
        ddlGeneration = ddlGeneration.toLowerCase();
        if(ddlGeneration.equals(NONE)) 
            return;

        if(ddlGeneration.equals(CREATE_ONLY) || 
            ddlGeneration.equals(DROP_AND_CREATE)) {
            createTables = true;
            if(ddlGeneration.equals(DROP_AND_CREATE)) {
                shouldDropFirst = true;
            }
        } 

        if(createTables) {
            appLocation = props.getProperty(
                    APP_LOCATION, DEFAULT_APP_LOCATION);
            createDDLJdbc = props.getProperty(
                    CREATE_JDBC_DDL_FILE, DEFAULT_CREATE_JDBC_FILE_NAME);
            dropDDLJdbc = props.getProperty(
                    DROP_JDBC_DDL_FILE, DEFAULT_DROP_JDBC_FILE_NAME);
            SchemaManager mgr = new SchemaManager(session);

            if(inSEmode) {
                runInSEMode(mgr, shouldDropFirst);
            }
        
            writeDDLsToFiles(mgr, shouldDropFirst, appLocation,  createDDLJdbc,  dropDDLJdbc);
        }
    }

  /**
   * Create a list of the entities that will be deployed.  This list is build from the information
   * provided in the PersistenceUnitInfo argument.
   * The list contains Classes specified in the PersistenceUnitInfo's class list and also
   * files that are annotated with @Entity, @Embeddable and @EmbeddableSuperclass in
   * the jar files provided in the persistence info.
   * This list of classes will used by TopLink to build a deployment project and to 
   * decide what classes to weave.
   * @param info 
   * @param loader 
   * @return 
   */
    public static Collection buildEntityList(PersistenceUnitInfo info, ClassLoader loader) {
        Vector classNames = new Vector();
        classNames.addAll(info.getManagedClassNames());
        Iterator i = info.getJarFileUrls().iterator();
        while (i.hasNext()){
            classNames.addAll(PersistenceUnitProcessor.getPersistentClassNamesFromURL((URL)i.next(), loader));
        }
        if (!info.excludeUnlistedClasses()){
            classNames.addAll(PersistenceUnitProcessor.getPersistentClassNamesFromURL(info.getPersistenceUnitRootUrl(), loader));
        }
        Vector entityList = new Vector();
        i = classNames.iterator();
        String className = null;
        while (i.hasNext()){
            try{
                className = (String)i.next();
                Class entityClass = loader.loadClass(className);
                entityList.add(entityClass);
            } catch (ClassNotFoundException exc){
                AbstractSessionLog.getLog().log(SessionLog.CONFIG, "exception_loading_entity_class", className, exc);
            }
        }        
        return entityList;
    }
   
    /**
     * @see {@link Persistence#createEntityManagerFactory()}.
     */
    protected ServerSession getServerSession(String emName, Map m) {
        JavaSECMPInitializer initializer = JavaSECMPInitializer.getJavaSECMPInitializer(m);
        return initializer.getServerSession(emName, m);
    }

  /**
   * Get the named property from the map of provided properties.  If it is not available 
   * in that map, check the System properties
   * @param propertyName 
   * @param providedProperties 
   * @return the value of the give property
   */
    public static String getConfigProperty(String propertyName, Map providedProperties) {
        String property = (String)providedProperties.get(propertyName);
        if (property == null) {
            property = System.getProperty(propertyName);
        }
        return property;
    }

    protected Properties getPersistenceUnitProperties(String emName, Map m) {
        JavaSECMPInitializer initializer = JavaSECMPInitializer.getJavaSECMPInitializer(m);
        return initializer.getPersistenceUnitProperties(emName);
    }
            
    private void runInSEMode(SchemaManager mgr, boolean shouldDropFirst) {
        boolean interactWithDB = getJava2dbSystemProperty();
        if (!interactWithDB)
            return;
        
        createOrReplaceDefaultTables(mgr, shouldDropFirst);
    }
    
    private boolean getJava2dbSystemProperty() {
        String str = System.getProperty(JAVASE_DB_INTERACTION, "true");
        return Boolean.valueOf(str.toLowerCase()).booleanValue();
    }
    
    private void createOrReplaceDefaultTables(
        SchemaManager mgr, boolean shouldDropFirst) {          
        if (shouldDropFirst) 
            mgr.replaceDefaultTables();
        else
            mgr.createDefaultTables();
    }

    private void writeDDLsToFiles(SchemaManager mgr,  
        boolean shouldDropFirst, String appLocation,
        String createDDLJdbc, String dropDDLJdbc) {
        // Ensure that the appLocation string ends with  File.seperator 
        appLocation = addFileSeperator(appLocation);
        if (null != createDDLJdbc) {
            String createJdbcFileName = appLocation + createDDLJdbc;
            mgr.outputCreateDDLToFile(createJdbcFileName);
        }

        if (null != dropDDLJdbc) {
            String dropJdbcFileName = appLocation + dropDDLJdbc;              
            mgr.outputDropDDLToFile(dropJdbcFileName);
        }

        mgr.setCreateSQLFiles(false);            
        createOrReplaceDefaultTables(mgr, shouldDropFirst);
    }
    
    private String addFileSeperator(String appLocation) {
        int strLength = appLocation.length();
        if (appLocation.substring(strLength -1, strLength).equals(File.separator)) 
            return appLocation;
        else
            return appLocation + File.separator;        
    }
    
}