package org.apache.tuscany.binding.jms;

import java.util.Properties;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.Session;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class SimpleJMSResourceFactory implements JMSResourceFactory {
		
	private JMSBinding jmsBinding;
	private Connection con;
	private Context context;
	private boolean isConnectionStarted;

	public  SimpleJMSResourceFactory(JMSBinding jmsBinding){
		this.jmsBinding = jmsBinding;
	}
	
	/* 
	 * This is a simple implementation where a connection is created per binding
	 * Ideally the resource factory should be able to leverage the host environment
	 * to provide connection pooling if it can.
	 * 
	 * For ex If Tuscany is running inside an AppServer
	 * Then we could leverage the JMS resources it provides
	 *
	 * @see org.apache.tuscany.binding.jms.JMSResourceFactory#getConnection()
	 */
	public Connection getConnection() throws NamingException, JMSException{
		if (con == null){
			createConnection();			
		}
		return con;
	}
	
	/* (non-Javadoc)
	 * @see org.apache.tuscany.binding.jms.JMSResourceFactory#createSession()
	 */
	public Session createSession() throws JMSException, NamingException{
		return getConnection().createSession(false, Session.AUTO_ACKNOWLEDGE);
	}
	
	/* (non-Javadoc)
	 * @see org.apache.tuscany.binding.jms.JMSResourceFactory#startConnection()
	 */
	public void startConnection() throws JMSException, NamingException{
		if(!isConnectionStarted){
			getConnection().start();
			isConnectionStarted = true;
		}
	}
	
	/* (non-Javadoc)
	 * @see org.apache.tuscany.binding.jms.JMSResourceFactory#closeConnection()
	 */
	public void closeConnection() throws JMSException, NamingException{
		if(con != null){	
			con.close();
		}
	}
	
	/* (non-Javadoc)
	 * @see org.apache.tuscany.binding.jms.JMSResourceFactory#createTextMessage(javax.jms.Session)
	 */
	public Message createMessage(Session session) throws JMSException{
		javax.jms.Message message = session.createTextMessage();  // default
    	message.setJMSDeliveryMode(jmsBinding.getDeliveryMode());
    	message.setJMSPriority(jmsBinding.getPriority());
    	
    	return message;
	}

	private void createConnection() throws NamingException, JMSException {
		if(context == null){
			createInitialContext();
		}
		ConnectionFactory conFac = (ConnectionFactory)context.lookup(jmsBinding.getConnectionFactoryName());
		con = conFac.createConnection();		
	}
	
	private void createInitialContext() throws NamingException{
		Properties props = new Properties();
    	props.setProperty(Context.INITIAL_CONTEXT_FACTORY,jmsBinding.getInitialContextFactoryName());
    	props.setProperty(Context.PROVIDER_URL,jmsBinding.getJNDIProviderURL());
    	
    	context = new InitialContext(props);
	}

}