/*
 * Copyright 2005-2010 the original author or authors.
 * 
 * Licensed 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.wamblee.cdi;

import java.util.logging.Logger;

import javax.enterprise.inject.spi.BeanManager;
import javax.naming.InitialContext;
import javax.naming.NamingException;

/**
 * Class that encapsulates beanmanager lookup in a way so that the lookup can be
 * explicitly overriden (e.g. for unit test).
 * 
 * In case no bean manager is found the beanmanager is set to null and the
 * problem is logged.
 * 
 * @author Erik Brakkee
 */
public class BeanManagerLookup {

    private static final Logger LOGGER = Logger
        .getLogger(BeanManagerLookup.class.getName());

    public static final String BEAN_MANAGER_JNDI = "java:comp/BeanManager";
    private static BeanManager BEAN_MANAGER = null;

    /**
     * Sets the bean manager (mainly for testability).
     * 
     * @param aMgr
     *            Bean manager.
     */
    public static void setBeanManager(BeanManager aMgr) {
        BEAN_MANAGER = aMgr;
    }

    /**
     * Looks up the bean manager if not already cached and returns it.
     * 
     * @return Bean manager.
     */
    public static BeanManager lookup() {
        if (BEAN_MANAGER == null) {
            try {
                InitialContext ctx = new InitialContext();
                BEAN_MANAGER = (BeanManager) ctx.lookup(BEAN_MANAGER_JNDI);
                LOGGER.info("Beanmanager successfully located");
            } catch (NamingException e) {
                LOGGER.warning("No beanmanager was found, using null");
                BEAN_MANAGER = null;
            }
        }
        return BEAN_MANAGER;
    }
}