// ========================================================================
   // Copyright (c) 2006-2009 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.net.URI;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.ServiceLoader;
  
  import javax.servlet.ServletContainerInitializer;
  import javax.servlet.ServletContext;
  import javax.servlet.annotation.HandlesTypes;
  
  
  import org.eclipse.jetty.annotations.AnnotationParser.DiscoverableAnnotationHandler;
  import org.eclipse.jetty.plus.annotation.ContainerInitializer;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  import org.eclipse.jetty.util.resource.Resource;
  import org.eclipse.jetty.webapp.Configuration;
  import org.eclipse.jetty.webapp.AbstractConfiguration;
  import org.eclipse.jetty.webapp.Descriptor;
  import org.eclipse.jetty.webapp.DiscoveredAnnotation;
  import org.eclipse.jetty.webapp.FragmentDescriptor;
  import org.eclipse.jetty.webapp.MetaDataComplete;
  import org.eclipse.jetty.webapp.WebAppContext;
  import org.eclipse.jetty.webapp.WebDescriptor;
  
  /**
   * Configuration for Annotations
   *
   *
   */
  public class AnnotationConfiguration extends AbstractConfiguration
  {
      private static final Logger LOG = Log.getLogger(AnnotationConfiguration.class);
      public static final String CLASS_INHERITANCE_MAP  = "org.eclipse.jetty.classInheritanceMap";    
      
      public void preConfigure(final WebAppContext context) throws Exception
      {
      }
     
      @Override
      public void configure(WebAppContext context) throws Exception
      {
         boolean metadataComplete = context.getMetaData().isMetaDataComplete();
         context.addDecorator(new AnnotationDecorator(context));   
        
          if (metadataComplete)
          {
              //Never scan any jars or classes for annotations if metadata is complete
              if (LOG.isDebugEnabled()) LOG.debug("Metadata-complete==true,  not processing annotations for context "+context);
              return;
          }
          else 
          {
              //Only scan jars and classes if metadata is not complete and the web app is version 3.0, or
              //a 2.5 version webapp that has specifically asked to discover annotations
              if (LOG.isDebugEnabled()) LOG.debug("parsing annotations");
              
              AnnotationParser parser = createAnnotationParser();
              //Discoverable annotations - those that you have to look for without loading a class
              parser.registerAnnotationHandler("javax.servlet.annotation.WebServlet", new WebServletAnnotationHandler(context));
              parser.registerAnnotationHandler("javax.servlet.annotation.WebFilter", new WebFilterAnnotationHandler(context));
              parser.registerAnnotationHandler("javax.servlet.annotation.WebListener", new WebListenerAnnotationHandler(context));
              ClassInheritanceHandler classHandler = new ClassInheritanceHandler();
              parser.registerClassHandler(classHandler);
              registerServletContainerInitializerAnnotationHandlers(context, parser);
              
              if (context.getServletContext().getEffectiveMajorVersion() >= 3 || context.isConfigurationDiscovered())
              {
                  if (LOG.isDebugEnabled()) LOG.debug("Scanning all classses for annotations: webxmlVersion="+context.getServletContext().getEffectiveMajorVersion()+" configurationDiscovered="+context.isConfigurationDiscovered());
                  parseContainerPath(context, parser);
                  //email from Rajiv Mordani jsrs 315 7 April 2010
                  //    If there is a <others/> then the ordering should be 
                  //          WEB-INF/classes the order of the declared elements + others.
                  //    In case there is no others then it is 
                  //          WEB-INF/classes + order of the elements.
                  parseWebInfClasses(context, parser);
                  parseWebInfLib (context, parser);
              } 
              
              //save the type inheritance map created by the parser for later reference
              context.setAttribute(CLASS_INHERITANCE_MAP, classHandler.getMap());
          }    
      }
      
     /**
      * @return a new AnnotationParser. This method can be overridden to use a different impleemntation of
      * the AnnotationParser. Note that this is considered internal API.
      */
     protected AnnotationParser createAnnotationParser()
     {
         return new AnnotationParser();
     }
     
     @Override
     public void cloneConfigure(WebAppContext template, WebAppContext context) throws Exception
     {
         context.addDecorator(new AnnotationDecorator(context));   
     }
     
 
     public void registerServletContainerInitializerAnnotationHandlers (WebAppContext context, AnnotationParser parser)
     throws Exception
     {     
         //TODO verify my interpretation of the spec. That is, that metadata-complete has nothing
         //to do with finding the ServletContainerInitializers, classes designated to be of interest to them,
         //or even calling them on startup. 
         
         //Get all ServletContainerInitializers, and check them for HandlesTypes annotations.
         //For each class in the HandlesTypes value, if it IS an annotation, register a handler
         //that will record the classes that have that annotation.
         //If it is NOT an annotation, then we will interrogate the type hierarchy discovered during
         //parsing later on to find the applicable classes.
         ArrayList<ContainerInitializer> initializers = new ArrayList<ContainerInitializer>();
         context.setAttribute(ContainerInitializerConfiguration.CONTAINER_INITIALIZERS, initializers);
         
         //We use the ServiceLoader mechanism to find the ServletContainerInitializer classes to inspect
         ServiceLoader<ServletContainerInitializer> loadedInitializers = ServiceLoader.load(ServletContainerInitializer.class, context.getClassLoader());
        
         if (loadedInitializers != null)
         {
             for (ServletContainerInitializer service : loadedInitializers)
             {
                 if (!isFromExcludedJar(context, service))
                 { 
                     HandlesTypes annotation = service.getClass().getAnnotation(HandlesTypes.class);
                     ContainerInitializer initializer = new ContainerInitializer();
                     initializer.setTarget(service);
                     initializers.add(initializer);
                     if (annotation != null)
                     {
                         Class[] classes = annotation.value();
                         if (classes != null)
                         {
                             initializer.setInterestedTypes(classes);
                             for (Class c: classes)
                             {
                                 if (c.isAnnotation())
                                 {
                                     if (LOG.isDebugEnabled()) LOG.debug("Registering annotation handler for "+c.getName());
                                     parser.registerAnnotationHandler(c.getName(), new ContainerInitializerAnnotationHandler(initializer, c));
                                 }
                             }
                         }
                         else
                             if (LOG.isDebugEnabled()) LOG.debug("No classes in HandlesTypes on initializer "+service.getClass());
                     }
                     else
                         if (LOG.isDebugEnabled()) LOG.debug("No annotation on initializer "+service.getClass());
                 }
             }
         }
     }
     
     /**
      * Check to see if the ServletContainerIntializer loaded via the ServiceLoader came
      * from a jar that is excluded by the fragment ordering. See ServletSpec 3.0 p.85.
      * @param orderedJars
      * @param service
      * @return
      */
     public boolean isFromExcludedJar (WebAppContext context, ServletContainerInitializer service)
     throws Exception
     {
         List<Resource> orderedJars = context.getMetaData().getOrderedWebInfJars();
 
         //If no ordering, nothing is excluded
         if (context.getMetaData().getOrdering() == null)
             return false;
 
         //there is an ordering, but there are no jars resulting from the ordering, everything excluded
         if (orderedJars.isEmpty())
             return true; 
 
         String loadingJarName = Thread.currentThread().getContextClassLoader().getResource(service.getClass().getName().replace('.','/')+".class").toString();
 
         int i = loadingJarName.indexOf(".jar");  
         if (i < 0)
             return false; //not from a jar therefore not from WEB-INF so not excludable
 
         loadingJarName = loadingJarName.substring(0,i+4);
         loadingJarName = (loadingJarName.startsWith("jar:")?loadingJarName.substring(4):loadingJarName);
         URI loadingJarURI = Resource.newResource(loadingJarName).getURI();
         boolean found = false;
         Iterator<Resource> itor = orderedJars.iterator();
         while (!found && itor.hasNext())
         {
             Resource r = itor.next();         
             found = r.getURI().equals(loadingJarURI);
         }
 
         return !found;
     }
    
     public void parseContainerPath (final WebAppContext context, final AnnotationParser parser)
     throws Exception
     {
         //if no pattern for the container path is defined, then by default scan NOTHING
         LOG.debug("Scanning container jars");
         
         //clear any previously discovered annotations
         clearAnnotationList(parser.getAnnotationHandlers());       
         
         //Convert from Resource to URI
         ArrayList<URI> containerUris = new ArrayList<URI>();
         for (Resource r : context.getMetaData().getOrderedContainerJars())
         {
             URI uri = r.getURI();
                 containerUris.add(uri);          
         }
         
         parser.parse (containerUris.toArray(new URI[containerUris.size()]),
                 new ClassNameResolver ()
                 {
                     public boolean isExcluded (String name)
                     {
                         if (context.isSystemClass(name)) return false;
                         if (context.isServerClass(name)) return true;
                         return false;
                     }
 
                     public boolean shouldOverride (String name)
                     { 
                         //looking at system classpath
                         if (context.isParentLoaderPriority())
                             return true;
                         return false;
                     }
                 });
         
         //gather together all annotations discovered
         List<DiscoveredAnnotation> annotations = new ArrayList<DiscoveredAnnotation>();
         gatherAnnotations(annotations, parser.getAnnotationHandlers());
 
         context.getMetaData().addDiscoveredAnnotations(annotations);           
     }
     
     
     public void parseWebInfLib (final WebAppContext context, final AnnotationParser parser)
     throws Exception
     {  
         List<FragmentDescriptor> frags = context.getMetaData().getFragments();
         
         //email from Rajiv Mordani jsrs 315 7 April 2010
         //jars that do not have a web-fragment.xml are still considered fragments
         //they have to participate in the ordering
         ArrayList<URI> webInfUris = new ArrayList<URI>();
         
         List<Resource> jars = context.getMetaData().getOrderedWebInfJars();
         
         //No ordering just use the jars in any order
         if (jars == null || jars.isEmpty())
             jars = context.getMetaData().getWebInfJars();
    
         for (Resource r : jars)
         {          
             //clear any previously discovered annotations from handlers
             clearAnnotationList(parser.getAnnotationHandlers());
 
             
             URI uri  = r.getURI();
             FragmentDescriptor f = getFragmentFromJar(r, frags);
            
             //if a jar has no web-fragment.xml we scan it (because it is not exluded by the ordering)
             //or if it has a fragment we scan it if it is not metadata complete
             if (f == null || !isMetaDataComplete(f))
             {
                 parser.parse(uri, 
                              new ClassNameResolver()
                              {
                                  public boolean isExcluded (String name)
                                  {    
                                      if (context.isSystemClass(name)) return true;
                                      if (context.isServerClass(name)) return false;
                                      return false;
                                  }
 
                                  public boolean shouldOverride (String name)
                                  {
                                     //looking at webapp classpath, found already-parsed class of same name - did it come from system or duplicate in webapp?
                                     if (context.isParentLoaderPriority())
                                         return false;
                                     return true;
                                  }
                              });  
                 List<DiscoveredAnnotation> annotations = new ArrayList<DiscoveredAnnotation>();
                 gatherAnnotations(annotations, parser.getAnnotationHandlers());
                 context.getMetaData().addDiscoveredAnnotations(r, annotations);
             }
         }
     }
      
     public void parseWebInfClasses (final WebAppContext context, final AnnotationParser parser)
     throws Exception
     {
         LOG.debug("Scanning classes in WEB-INF/classes");
         if (context.getWebInf() != null)
         {
             Resource classesDir = context.getWebInf().addPath("classes/");
             if (classesDir.exists())
             {
                 clearAnnotationList(parser.getAnnotationHandlers());
                 parser.parse(classesDir, 
                              new ClassNameResolver()
                 {
                     public boolean isExcluded (String name)
                     {
                         if (context.isSystemClass(name)) return true;
                         if (context.isServerClass(name)) return false;
                         return false;
                     }
 
                     public boolean shouldOverride (String name)
                     {
                         //looking at webapp classpath, found already-parsed class of same name - did it come from system or duplicate in webapp?
                         if (context.isParentLoaderPriority())
                             return false;
                         return true;
                     }
                 });
                 
                 //TODO - where to set the annotations discovered from WEB-INF/classes?    
                 List<DiscoveredAnnotation> annotations = new ArrayList<DiscoveredAnnotation>();
                 gatherAnnotations(annotations, parser.getAnnotationHandlers());
                 context.getMetaData().addDiscoveredAnnotations (annotations);
             }
         }
     }
     
  
     
     public FragmentDescriptor getFragmentFromJar (Resource jar,  List<FragmentDescriptor> frags)
     throws Exception
     {
         //check if the jar has a web-fragment.xml
         FragmentDescriptor d = null;
         for (FragmentDescriptor frag: frags)
         {
             Resource fragResource = frag.getResource(); //eg jar:file:///a/b/c/foo.jar!/META-INF/web-fragment.xml
             if (Resource.isContainedIn(fragResource,jar))
             {
                 d = frag;
                 break;
             }
         }
         return d;
     }
     
     public boolean isMetaDataComplete (WebDescriptor d)
     {
         return (d!=null && d.getMetaDataComplete() == MetaDataComplete.True);
     }
     
     protected void clearAnnotationList (List<DiscoverableAnnotationHandler> handlers)
     {
         if (handlers == null)
             return;
         
         for (DiscoverableAnnotationHandler h:handlers)
         {
             if (h instanceof AbstractDiscoverableAnnotationHandler)
                 ((AbstractDiscoverableAnnotationHandler)h).resetList();
         }
     }
 
     protected void gatherAnnotations (List<DiscoveredAnnotation> annotations, List<DiscoverableAnnotationHandler> handlers)
     {
         for (DiscoverableAnnotationHandler h:handlers)
         {
             if (h instanceof AbstractDiscoverableAnnotationHandler)
                 annotations.addAll(((AbstractDiscoverableAnnotationHandler)h).getAnnotationList());
         }
     }
 }