/*
 * Copyright 2015 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
*/

package org.jbpm.process.audit.strategy;

import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.TransactionRequiredException;
import javax.transaction.Status;
import javax.transaction.UserTransaction;

import org.jbpm.process.audit.JPAWorkingMemoryDbLogger;
import org.kie.api.runtime.KieSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This strategy is used by instances that are<ul>
 * <li>used outside the {@link KieSession}</li>
 * <li>use their own {@link EntityManager} instance per operation</li>
 * </ul>
 */
public class StandaloneLocalStrategy implements PersistenceStrategy {

    protected EntityManagerFactory emf;
    
    public StandaloneLocalStrategy(EntityManagerFactory emf) { 
        this.emf = emf;
    }
    
    @Override
    public EntityManager getEntityManager() {
        return emf.createEntityManager();
    }

    @Override
    public Object joinTransaction(EntityManager em) {
       em.getTransaction().begin(); 
       return true;
    }

    @Override
    public void leaveTransaction(EntityManager em, Object transaction) {
        em.getTransaction().commit();
        em.close();
    }

    @Override
    public void dispose() {
        // NEVER close the emf, you don't know what it is also being used for!
        emf = null;
    }
}
