// ========================================================================
   // Copyright (c) 2010 Mort Bay Consulting Pty. Ltd.
   // ------------------------------------------------------------------------
   // All rights reserved. This program and the accompanying materials
   // are made available under the terms of the Eclipse Public License v1.0
   // and Apache License v2.0 which accompanies this distribution.
   // The Eclipse Public License is available at 
   // http://www.eclipse.org/legal/epl-v10.html
   // The Apache License v2.0 is available at
  // http://www.opensource.org/licenses/apache2.0.php
  // You may elect to redistribute this code under either of these licenses. 
  // ========================================================================
  
  package org.eclipse.jetty.annotations;
  
  import java.util.ArrayList;
  
  import javax.servlet.annotation.WebInitParam;
  import javax.servlet.annotation.WebServlet;
  import javax.servlet.http.HttpServlet;
  
  import org.eclipse.jetty.servlet.Holder;
  import org.eclipse.jetty.servlet.ServletHolder;
  import org.eclipse.jetty.servlet.ServletMapping;
  import org.eclipse.jetty.util.LazyList;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  import org.eclipse.jetty.webapp.DiscoveredAnnotation;
  import org.eclipse.jetty.webapp.MetaData;
  import org.eclipse.jetty.webapp.WebAppContext;
  import org.eclipse.jetty.webapp.Origin;
  
  /**
   * WebServletAnnotation
   *
   *
   */
  public class WebServletAnnotation extends DiscoveredAnnotation
  {
      private static final Logger LOG = Log.getLogger(WebServletAnnotation.class);
      
      public WebServletAnnotation (WebAppContext context, String className)
      {
          super(context, className);
      }
  
      /** 
       * @see org.eclipse.jetty.annotations.ClassAnnotation#apply()
       */
      public void apply()
      {
          //TODO check this algorithm with new rules for applying descriptors and annotations in order
          Class clazz = getTargetClass();
          
          if (clazz == null)
          {
              LOG.warn(_className+" cannot be loaded");
              return;
          }
          
          //Servlet Spec 8.1.1
          if (!HttpServlet.class.isAssignableFrom(clazz))
          {
              LOG.warn(clazz.getName()+" is not assignable from javax.servlet.http.HttpServlet");
              return;
          }
          
          WebServlet annotation = (WebServlet)clazz.getAnnotation(WebServlet.class);
          
          if (annotation.urlPatterns().length > 0 && annotation.value().length > 0)
          {
              LOG.warn(clazz.getName()+ " defines both @WebServlet.value and @WebServlet.urlPatterns");
              return;
          }
          
          String[] urlPatterns = annotation.value();
          if (urlPatterns.length == 0)
              urlPatterns = annotation.urlPatterns();
          
          if (urlPatterns.length == 0)
          {
              LOG.warn(clazz.getName()+ " defines neither @WebServlet.value nor @WebServlet.urlPatterns");
              return;
          }
          
          //canonicalize the patterns
          ArrayList<String> urlPatternList = new ArrayList<String>();
          for (String p : urlPatterns)
              urlPatternList.add(Util.normalizePattern(p));
          
          String servletName = (annotation.name().equals("")?clazz.getName():annotation.name());
          
          MetaData metaData = _context.getMetaData();
  
          //Find out if a <servlet>  of this type already exists with this name
          ServletHolder[] holders = _context.getServletHandler().getServlets();
          boolean isNew = true;
          ServletHolder holder = null;
          if (holders != null)
         {
             for (ServletHolder h : holders)
             {
                 if (h.getClassName().equals(clazz.getName()) && h.getName().equals(servletName))
                 {
                     holder = h;
                     isNew = false;
                     break;
                 }
             }
         }
 
         if (isNew)
         {
             //No servlet of this name has already been defined, either by a descriptor
             //or another annotation (which would be impossible).
             holder = _context.getServletHandler().newServletHolder(Holder.Source.ANNOTATION);
             holder.setHeldClass(clazz);   
             metaData.setOrigin(servletName+".servlet.servlet-class");
             
             holder.setName(servletName);
             holder.setDisplayName(annotation.displayName());
             metaData.setOrigin(servletName+".servlet.display-name");
             
             holder.setInitOrder(annotation.loadOnStartup());
             metaData.setOrigin(servletName+".servlet.load-on-startup");
             
             holder.setAsyncSupported(annotation.asyncSupported());
             metaData.setOrigin(servletName+".servlet.async-supported");
             
             for (WebInitParam ip:annotation.initParams())
             {
                 holder.setInitParameter(ip.name(), ip.value());
                 metaData.setOrigin(servletName+".servlet.init-param."+ip.name());
             }
           
             _context.getServletHandler().addServlet(holder);
             ServletMapping mapping = new ServletMapping();  
             mapping.setServletName(holder.getName());
             mapping.setPathSpecs( LazyList.toStringArray(urlPatternList));
             _context.getServletHandler().addServletMapping(mapping);
             metaData.setOrigin(servletName+".servlet.mappings");
         }
         else
         {
             //check if the existing servlet has each init-param from the annotation
             //if not, add it
             for (WebInitParam ip:annotation.initParams())
             {
               //if (holder.getInitParameter(ip.name()) == null)
                 if (metaData.getOrigin(servletName+".servlet.init-param"+ip.name())==Origin.NotSet)
                 {
                     holder.setInitParameter(ip.name(), ip.value());
                     metaData.setOrigin(servletName+".servlet.init-param."+ip.name());
                 }  
             }
             
             //check the url-patterns, if there annotation has a new one, add it
             ServletMapping[] mappings = _context.getServletHandler().getServletMappings();
 
             //ServletSpec 3.0 p81 If a servlet already has url mappings from a 
             //descriptor the annotation is ignored
             if (mappings == null && metaData.getOriginDescriptor(servletName+".servlet.mappings") != null)
             {
                 ServletMapping mapping = new ServletMapping();
                 mapping.setServletName(servletName);
                 mapping.setPathSpecs(LazyList.toStringArray(urlPatternList));
                 _context.getServletHandler().addServletMapping(mapping); 
             }
         }
     }   
 }