// ========================================================================
   // Copyright (c) 2006-2011 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.osgi.annotations;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.eclipse.jetty.annotations.ClassNameResolver;
  import org.eclipse.jetty.osgi.boot.OSGiWebappConstants;
  import org.eclipse.jetty.osgi.boot.utils.internal.PackageAdminServiceTracker;
  import org.eclipse.jetty.util.resource.Resource;
  import org.eclipse.jetty.webapp.DiscoveredAnnotation;
  import org.eclipse.jetty.webapp.WebAppContext;
  import org.osgi.framework.Bundle;
  import org.osgi.framework.Constants;
  
  /**
   * Extend the AnnotationConfiguration to support OSGi:
   * Look for annotations inside WEB-INF/lib and also in the fragments and required bundles.
   * Discover them using a scanner adapted to OSGi instead of the jarscanner. 
   */
  public class AnnotationConfiguration extends org.eclipse.jetty.annotations.AnnotationConfiguration
  {
  
      /**
       * This parser scans the bundles using the OSGi APIs instead of assuming a jar.
       */
      @Override
      protected org.eclipse.jetty.annotations.AnnotationParser createAnnotationParser()
      {
          return new AnnotationParser();
      }
      
      /**
       * Here is the order in which jars and osgi artifacts are scanned for discoverable annotations.
       * <ol>
       * <li>The container jars are scanned.</li>
       * <li>The WEB-INF/classes are scanned</li>
       * <li>The osgi fragment to the web bundle are parsed.</li>
       * <li>The WEB-INF/lib are scanned</li>
       * <li>The required bundles are parsed</li>
       * </ol>
       */
      @Override
      public void parseWebInfLib (WebAppContext context, org.eclipse.jetty.annotations.AnnotationParser parser)
      throws Exception
      {
          AnnotationParser oparser = (AnnotationParser)parser;
          
          Bundle webbundle = (Bundle) context.getAttribute(OSGiWebappConstants.JETTY_OSGI_BUNDLE);
          Bundle[] fragAndRequiredBundles = PackageAdminServiceTracker.INSTANCE.getFragmentsAndRequiredBundles(webbundle);
          if (fragAndRequiredBundles != null)
          {
              //index:
              for (Bundle bundle : fragAndRequiredBundles)
              {
                  Resource bundleRes = oparser.indexBundle(bundle);
                  if (!context.getMetaData().getWebInfJars().contains(bundleRes))
                  {
                      context.getMetaData().addWebInfJar(bundleRes);
                  }
              }
          
              //scan the fragments
              for (Bundle fragmentBundle : fragAndRequiredBundles)
              {
                  if (fragmentBundle.getHeaders().get(Constants.FRAGMENT_HOST) != null)
                  {
                      //a fragment indeed:
                      parseFragmentBundle(context,oparser,webbundle,fragmentBundle);
                  }
              }
          }
          //scan ourselves
          parseWebBundle(context,oparser,webbundle);
          
          //scan the WEB-INF/lib
          super.parseWebInfLib(context,parser);
          if (fragAndRequiredBundles != null)
          {
              //scan the required bundles
              for (Bundle requiredBundle : fragAndRequiredBundles)
              {
                  if (requiredBundle.getHeaders().get(Constants.FRAGMENT_HOST) == null)
                  {
                      //a bundle indeed:
                      parseRequiredBundle(context,oparser,webbundle,requiredBundle);
                  }
              }
         }
     }
     
     /**
      * Scan a fragment bundle for servlet annotations
      * @param context The webapp context
      * @param parser The parser
      * @param webbundle The current webbundle
      * @param fragmentBundle The OSGi fragment bundle to scan
      * @throws Exception
      */
     protected void parseFragmentBundle(WebAppContext context, AnnotationParser parser,
             Bundle webbundle, Bundle fragmentBundle) throws Exception
     {
         parseBundle(context,parser,webbundle,fragmentBundle);
     }
     
     /**
      * Scan a bundle required by the webbundle for servlet annotations
      * @param context The webapp context
      * @param parser The parser
      * @param webbundle The current webbundle
      * @param fragmentBundle The OSGi required bundle to scan
      * @throws Exception
      */
     protected void parseWebBundle(WebAppContext context, AnnotationParser parser, Bundle webbundle)
     throws Exception
     {
         parseBundle(context,parser,webbundle,webbundle);
     }
     
     /**
      * Scan a bundle required by the webbundle for servlet annotations
      * @param context The webapp context
      * @param parser The parser
      * @param webbundle The current webbundle
      * @param fragmentBundle The OSGi required bundle to scan
      * @throws Exception
      */
     protected void parseRequiredBundle(WebAppContext context, AnnotationParser parser,
             Bundle webbundle, Bundle requiredBundle) throws Exception
     {
         parseBundle(context,parser,webbundle,requiredBundle);
     }
     
     protected void parseBundle(WebAppContext context, AnnotationParser parser,
             Bundle webbundle, Bundle bundle) throws Exception
     {
         Resource bundleRes = parser.getResource(bundle);
         parser.parse(bundle,createClassNameResolver(context));
         List<DiscoveredAnnotation> annotations = new ArrayList<DiscoveredAnnotation>();
         gatherAnnotations(annotations, parser.getAnnotationHandlers());
         if (webbundle == bundle)
         {
             //just like the super with its question about annotations in WEB-INF/classes:
             //"TODO - where to set the annotations discovered from WEB-INF/classes?"
             context.getMetaData().addDiscoveredAnnotations(annotations);
         }
         else
         {
             context.getMetaData().addDiscoveredAnnotations(bundleRes, annotations);
         }
     }
     
     /**
      * Returns the same classname resolver than for the webInfjar scanner
      * @param context
      * @return
      */
     protected ClassNameResolver createClassNameResolver(final WebAppContext context)
     {
         return createClassNameResolver(context,true,false,false,false);
     }
     
     protected ClassNameResolver createClassNameResolver(final WebAppContext context,
             final boolean excludeSysClass, final boolean excludeServerClass, final boolean excludeEverythingElse,
             final boolean overrideIsParenLoaderIsPriority)
     {
         return new ClassNameResolver ()
         {
             public boolean isExcluded (String name)
             {
                 if (context.isSystemClass(name)) return excludeSysClass;
                 if (context.isServerClass(name)) return excludeServerClass;
                 return excludeEverythingElse;
             }
 
             public boolean shouldOverride (String name)
             { 
                 //looking at system classpath
                 if (context.isParentLoaderPriority())
                     return overrideIsParenLoaderIsPriority;
                 return !overrideIsParenLoaderIsPriority;
             }
         };
     }
 
 }