/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2011, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.cache.ehcache;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicInteger;

import net.sf.ehcache.CacheManager;
import net.sf.ehcache.config.Configuration;
import org.jboss.logging.Logger;

import org.hibernate.cache.CacheException;
import org.hibernate.cache.ehcache.internal.util.HibernateUtil;
import org.hibernate.cfg.Settings;

/**
 * A singleton EhCacheRegionFactory implementation.
 *
 * @author Chris Dennis
 * @author Greg Luck
 * @author Emmanuel Bernard
 * @author Alex Snaps
 */
public class SingletonEhCacheRegionFactory extends AbstractEhcacheRegionFactory {

    private static final EhCacheMessageLogger LOG = Logger.getMessageLogger(
            EhCacheMessageLogger.class,
            SingletonEhCacheRegionFactory.class.getName()
    );
    private static final AtomicInteger REFERENCE_COUNT = new AtomicInteger();

    /**
     * Returns a representation of the singleton EhCacheRegionFactory
     */
    public SingletonEhCacheRegionFactory(Properties prop) {
        super();
    }

    /**
     * {@inheritDoc}
     */
    public void start(Settings settings, Properties properties) throws CacheException {
        try {
            String configurationResourceName = null;
            if ( properties != null ) {
                configurationResourceName = (String) properties.get( NET_SF_EHCACHE_CONFIGURATION_RESOURCE_NAME );
            }
            if ( configurationResourceName == null || configurationResourceName.length() == 0 ) {
                manager = CacheManager.create();
                REFERENCE_COUNT.incrementAndGet();
            }
            else {
                URL url;
                try {
                    url = new URL( configurationResourceName );
                }
                catch ( MalformedURLException e ) {
                    if ( !configurationResourceName.startsWith( "/" ) ) {
                        configurationResourceName = "/" + configurationResourceName;
                        LOG.debugf(
                                "prepending / to %s. It should be placed in the root of the classpath rather than in a package.",
                                configurationResourceName
                        );
                    }
                    url = loadResource( configurationResourceName );
                }
                Configuration configuration = HibernateUtil.loadAndCorrectConfiguration( url );
                manager = CacheManager.create( configuration );
                REFERENCE_COUNT.incrementAndGet();
            }
            mbeanRegistrationHelper.registerMBean( manager, properties );
        }
        catch ( net.sf.ehcache.CacheException e ) {
            throw new CacheException( e );
        }
    }

    /**
     * {@inheritDoc}
     */
    public void stop() {
        try {
            if ( manager != null ) {
                if ( REFERENCE_COUNT.decrementAndGet() == 0 ) {
                    manager.shutdown();
                }
                manager = null;
            }
        }
        catch ( net.sf.ehcache.CacheException e ) {
            throw new CacheException( e );
        }
    }

}