/*
 * Copyright 2006 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.crawler.kiss.servlet;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.wamblee.crawler.kiss.scheduling.CrawlerScheduler;
import org.wamblee.general.BeanKernel;

/**
 * The mechanism for kick starting the scheduling of the KiSS crawler. 
 *
 * @author Erik Brakkee
 */
public class Application implements ServletContextListener {

    /**
     * Constructs the listener.
     *
     */
    public Application() { 
        // Empty. 
    }

    /*
     * (non-Javadoc)
     * 
     * @see javax.servlet.ServletContextListener#contextInitialized(javax.servlet.ServletContextEvent)
     */
    public void contextInitialized(ServletContextEvent aEvent) {
        aEvent.getServletContext().log("KiSS Crawler initializing");
        try {
            getScheduler().initialize();
        } catch (Exception e) {
            aEvent.getServletContext().log("Error scheduling job", e);
            return; 
        }
        aEvent.getServletContext().log("KiSS Crawler initialized");
    }

    /*
     * (non-Javadoc)
     * 
     * @see javax.servlet.ServletContextListener#contextDestroyed(javax.servlet.ServletContextEvent)
     */
    public void contextDestroyed(ServletContextEvent aEvent) {
        aEvent.getServletContext().log("KiSS Crawler shutting down");
        try {
            getScheduler().shutdown();
        } catch (Exception e) {
            aEvent.getServletContext().log("Error scheduling job", e);
            return; 
        }
        aEvent.getServletContext().log("KiSS Crawler shut down complete");
    }

    /**
     * Gets the scheduler from Spring. 
     * @return Scheduler. 
     */
    private CrawlerScheduler getScheduler() { 
        return BeanKernel.getBeanFactory().find(CrawlerScheduler.class);
    }

    public static void main(String[] aArgs) throws Exception {
        Application application = new Application();
        application.getScheduler().initialize();
    }
}