/*
    * Copyright 2010-2012 Capgemini
    * 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 net.sf.appstatus.web;
  
  import static org.apache.commons.lang3.StringUtils.defaultString;
  
  import java.io.IOException;
  import java.util.LinkedHashMap;
  import java.util.Map;
  
  import javax.servlet.ServletConfig;
  import javax.servlet.ServletContext;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import net.sf.appstatus.core.AppStatus;
  import net.sf.appstatus.core.AppStatusStatic;
  import net.sf.appstatus.core.IServletContextProvider;
  import net.sf.appstatus.web.pages.BatchPage;
  import net.sf.appstatus.web.pages.LoggersPage;
  import net.sf.appstatus.web.pages.RadiatorPage;
  import net.sf.appstatus.web.pages.ServicesPage;
  import net.sf.appstatus.web.pages.StatusPage;
  
  public class StatusServlet extends HttpServlet {
  
  	private static Logger logger = LoggerFactory.getLogger(AppStatus.class);
  	private static final long serialVersionUID = 3912325072098291029L;
  	private static StatusWebHandler statusWeb = null;
  
  	private void addPage(final Map<String, IPage> map, final IPage page) {
  		map.put(page.getId(), page);
  	}
  
  	/*
  	 * (non-Javadoc)
  	 *
  	 * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.
  	 * HttpServletRequest , javax.servlet.http.HttpServletResponse)
  	 */
  	@Override
  	protected void doGet(final HttpServletRequest req, final HttpServletResponse resp)
  			throws ServletException, IOException {
  		statusWeb.doGet(req, resp);
  	}
  
  	/*
  	 * (non-Javadoc)
  	 *
  	 * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.
  	 * HttpServletRequest , javax.servlet.http.HttpServletResponse)
  	 */
  	@Override
  	protected void doPost(final HttpServletRequest req, final HttpServletResponse resp)
  			throws ServletException, IOException {
  		statusWeb.doPost(req, resp);
  	}
  
  	/**
  	 * Init the AppStatus Web UI.
  	 * <p>
  	 * Read <b>bean</> init parameter. If defined, switch to Spring-enabled
  	 * behavior.
  	 */
  	@Override
  	public void init(final ServletConfig config) throws ServletException {
  		super.init(config);
  
  		super.init();
  
  		SpringObjectInstantiationListener instantiation = null;
  		final String beanName = getInitParameter("bean");
  		final String[] pagesBeanNames = StringUtils.split(getInitParameter("custom-pages"), ", ");
  		final Map<String, IPage> pages = new LinkedHashMap<String, IPage>();
  		;
  
  		AppStatus status;
  		if (beanName != null) {
  			// Using Spring
  			instantiation = new SpringObjectInstantiationListener(this.getServletContext());
 
 			// Status
 			status = (AppStatus) instantiation.getInstance(beanName);
 
 		} else {
 			status = AppStatusStatic.getInstance();
 
 		}
 
 		status.setServletContextProvider(new IServletContextProvider() {
 			public ServletContext getServletContext() {
 				return StatusServlet.this.getServletContext();
 			}
 		});
 
 		//
 		// Pages
 		addPage(pages, new StatusPage());
 
 		if (status.getServiceManager() != null) {
 			addPage(pages, new ServicesPage());
 		}
 
 		if (status.getBatchManager() != null) {
 			addPage(pages, new BatchPage());
 
 		}
 
 		if (status.getLoggersManager() != null) {
 			addPage(pages, new LoggersPage());
 
 		}
 
 		// Custom pages
 		if (pagesBeanNames != null) {
 			for (final String pageBean : pagesBeanNames) {
 
 				IPage newPage = null;
 
 				if (instantiation != null) {
 					newPage = (IPage) instantiation.getInstance(pageBean);
 					if (newPage == null) {
 						try {
 							newPage = (IPage) Thread.currentThread().getContextClassLoader().loadClass(pageBean)
 									.newInstance();
 						} catch (final ClassNotFoundException e) {
 							logger.warn("Class {} not found ", pageBean, e);
 						} catch (final InstantiationException e) {
 							logger.warn("Cannot instanciate {} ", pageBean, e);
 						} catch (final IllegalAccessException e) {
 							logger.warn("Cannot access class {} for instantiation ", pageBean, e);
 						}
 					}
 				}
 
 				addPage(pages, newPage);
 
 			}
 		}
 
 		// Radiator at the end.
 		addPage(pages, new RadiatorPage());
 
 		// Init
 		statusWeb = new StatusWebHandler();
 		statusWeb.setAppStatus(status);
 		statusWeb.setApplicationName(defaultString(config.getServletContext().getServletContextName(), "No name"));
 		statusWeb.setPages(pages);
 		statusWeb.init();
 	}
 }