import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.Name;
import javax.naming.RefAddr;
import javax.naming.Reference;
import javax.naming.event.EventContext;
import javax.naming.event.NamespaceChangeListener;
import javax.naming.event.NamingEvent;
import javax.naming.event.NamingExceptionEvent;
import javax.naming.spi.ObjectFactory;

import net.sf.ehcache.CacheManager;

public class CacheManagerFactory implements ObjectFactory {

	private static final String CONFIGURATION_FILE = "configurationFile";

	private static final NamespaceChangeListener SHUTDOWN_LISTENER = new NamespaceChangeListener() {

		@Override
		public void namingExceptionThrown(NamingExceptionEvent event) {}

		@Override
		public void objectAdded(NamingEvent event) {}

		@Override
		public void objectRemoved(NamingEvent event) {
			Object object = event.getOldBinding().getObject();
			if (object instanceof CacheManager) {
				CacheManager cacheManager = (CacheManager) object;
				cacheManager.shutdown();
			}
		}

		@Override
		public void objectRenamed(NamingEvent event) {}
	};

	@Override
	public CacheManager getObjectInstance(Object object, Name jndiName, Context context, Hashtable<?, ?> environment) throws Exception {
		String configurationFile = null;
		if (object instanceof Reference) {
			Reference reference = (Reference) object;
			RefAddr refAddr = reference.get(CONFIGURATION_FILE);
			if (refAddr != null) {
				configurationFile = (String) refAddr.getContent();
			}
		}
		if (context instanceof EventContext) {
			EventContext eventContext = (EventContext) context;
			eventContext.addNamingListener(jndiName, EventContext.OBJECT_SCOPE, SHUTDOWN_LISTENER);
		}
		return configurationFile == null ? CacheManager.newInstance() : CacheManager.newInstance(configurationFile);
	}
}