/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *    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.apache.ode.store.hib;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.ode.store.ConfStoreConnection;
import org.apache.ode.store.DeploymentUnitDAO;
import org.apache.ode.store.ProcessConfDAO;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.Query;
import org.hibernate.Session;

import javax.xml.namespace.QName;
import java.util.Collection;
import java.util.Date;

/**
 * Connection to a Hibernate data store. Essentially a thin wrapper around Hibernate's
 * {@link org.hibernate.Session} interface.
 * @author mriou <mriou at apache dot org>
 */
public class ConfStoreConnectionHib implements ConfStoreConnection {

    private static final Logger __log = LoggerFactory.getLogger(ConfStoreConnectionHib.class);
    private Session _session;

    static final ThreadLocal<Session> _current = new ThreadLocal<Session>();

    public ConfStoreConnectionHib(Session session) {
        _session = session;
        _current.set(session);
    }

    public ProcessConfDAO getProcess(QName pid) {
        try {
            return (ProcessConfDaoImpl) _session.get(ProcessConfDaoImpl.class,pid.toString());
        } catch (HibernateException e) {
            __log.error("DbError", e);
            throw e;
        }
    }


    public DeploymentUnitDAO createDeploymentUnit(String name) {
        DeploymentUnitDaoImpl du = new DeploymentUnitDaoImpl();
        du.setName(name);
        du.setDeployDate(new Date());
        _session.save(du);
        return du;
    }

    public DeploymentUnitDAO getDeploymentUnit(String name) {
        try {
            DeploymentUnitDaoImpl du = (DeploymentUnitDaoImpl) _session.get(DeploymentUnitDaoImpl.class,name);
            return du;
        } catch (HibernateException e) {
            __log.error("DbError", e);
            throw e;
        }
    }

    public long getNextVersion() {
        Query q = _session.createQuery("from VersionTrackerDAOImpl v ");
        q.setLockMode("v", LockMode.UPGRADE);
        VersionTrackerDAOImpl vt = (VersionTrackerDAOImpl) q.uniqueResult();
        if (vt == null) {
            vt = new VersionTrackerDAOImpl();
            vt.setVersion(1);
        }else {
            vt.setVersion(vt.getVersion() + 1);
        }
        _session.save(vt);
        return vt.getVersion();
    }

    public void setVersion(long version) {
        _session.flush();

        Query q = _session.createQuery("from VersionTrackerDAOImpl v ");
        q.setLockMode("v", LockMode.UPGRADE);
        VersionTrackerDAOImpl vt = (VersionTrackerDAOImpl) q.uniqueResult();
        if (vt == null) {
            vt = new VersionTrackerDAOImpl();
            vt.setId(1);
            vt.setVersion(1);
        } else {
            vt.setVersion(version);
        }
        _session.save(vt);
    }

    @SuppressWarnings("unchecked")
    public Collection<DeploymentUnitDAO> getDeploymentUnits() {
        Criteria c = _session.createCriteria(DeploymentUnitDaoImpl.class);
        return c.list();
    }

    public void close() {
        _session.close();
    }
}