/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.web;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.openmrs.module.Module;
import org.openmrs.module.ModuleFactory;
import org.openmrs.module.web.WebModuleUtil;
import org.openmrs.util.DatabaseUpdater;
import org.openmrs.util.OpenmrsClassLoader;
import org.openmrs.web.filter.initialization.InitializationFilter;
import org.openmrs.web.filter.update.UpdateFilter;
import org.springframework.beans.BeansException;

/**
 * This class is only used to get access to the DispatcherServlet. <br/>
 * <br/>
 * After creation, this object is saved to WebUtil for later use. When Spring's
 * webApplicationContext is refreshed, the DispatcherServlet needs to be refreshed too.
 * 
 * @see #reInitFrameworkServlet()
 */
public class DispatcherServlet extends org.springframework.web.servlet.DispatcherServlet {
	
	private static final long serialVersionUID = -6925172744402818729L;
	
	private Log log = LogFactory.getLog(this.getClass());
	
	/**
	 * @see org.springframework.web.servlet.FrameworkServlet#initFrameworkServlet()
	 */
	@Override
	protected void initFrameworkServlet() throws ServletException, BeansException {
		// refresh the application context to look for module xml config files as well
		
		//XmlWebApplicationContext wac = ((XmlWebApplicationContext)getWebApplicationContext());
		Thread.currentThread().setContextClassLoader(OpenmrsClassLoader.getInstance());
		//wac.refresh();
		
		log.debug("Framework being initialized");
		WebModuleUtil.setDispatcherServlet(this);
		
		super.initFrameworkServlet();
	}
	
	/**
	 * Called by the ModuleUtil after adding in a new module. This needs to be called because the
	 * new mappings and advice that a new module adds in are cached by Spring's DispatcherServlet.
	 * This method will reload that cache.
	 * 
	 * @throws ServletException
	 */
	public void reInitFrameworkServlet() throws ServletException {
		log.debug("Framework being REinitialized");
		Thread.currentThread().setContextClassLoader(OpenmrsClassLoader.getInstance());
		
		// reset bean info and framework servlet
		init();
		
		// the spring context gets reset by the framework servlet, so we need to 
		// reload the advice points that were lost when refreshing Spring
		for (Module module : ModuleFactory.getStartedModules()) {
			ModuleFactory.loadAdvice(module);
		}
	}
	
	/**
	 * @see javax.servlet.GenericServlet#init(javax.servlet.ServletConfig)
	 */
	@Override
	public void init(ServletConfig config) throws ServletException {
		super.init(config);
		
		// hacky way to know if one of the startup filters needs to be run
		if (UpdateFilter.updatesRequired() && !DatabaseUpdater.allowAutoUpdate()) {
			log.info("DB updates are required, the update wizard must be run");
		}
		if (InitializationFilter.initializationRequired()) {
			log.info("Runtime properties were not found or the database is empty, so initialization is required");
		}
	}
	
}