//
   //  ========================================================================
   //  Copyright (c) 1995-2016 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.HashSet;
  import java.util.Set;
  
  import org.eclipse.jetty.annotations.AnnotationParser.Handler;
  import org.eclipse.jetty.annotations.ClassNameResolver;
  import org.eclipse.jetty.osgi.boot.OSGiWebInfConfiguration;
  import org.eclipse.jetty.osgi.boot.OSGiWebappConstants;
  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.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
  {
      private static final Logger LOG = Log.getLogger(org.eclipse.jetty.annotations.AnnotationConfiguration.class);
      
      public class BundleParserTask extends ParserTask
      {
          
          public BundleParserTask (AnnotationParser parser, Set<? extends Handler>handlers, Resource resource, ClassNameResolver resolver)
          {
              super(parser, handlers, resource, resolver);
          }
  
          public Void call() throws Exception
          {
              if (_parser != null)
              {
                  org.eclipse.jetty.osgi.annotations.AnnotationParser osgiAnnotationParser = (org.eclipse.jetty.osgi.annotations.AnnotationParser)_parser;
                  Bundle bundle = osgiAnnotationParser.getBundle(_resource);
                  if (_stat != null)
                      _stat.start();
                  osgiAnnotationParser.parse(_handlers, bundle,  _resolver); 
                  if (_stat != null)
                      _stat.end();
              }
              return null;
          }
      }
      
      
      public 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);
          Set<Bundle> fragAndRequiredBundles = (Set<Bundle>)context.getAttribute(OSGiWebInfConfiguration.FRAGMENT_AND_REQUIRED_BUNDLES);
         if (fragAndRequiredBundles != null)
         {
             //index and scan fragments
             for (Bundle bundle : fragAndRequiredBundles)
             {
                 //skip bundles that have been uninstalled since we discovered them
                 if (bundle.getState() == Bundle.UNINSTALLED)
                     continue;
                 
                 Resource bundleRes = oparser.indexBundle(bundle);
                 if (!context.getMetaData().getWebInfJars().contains(bundleRes))
                 {
                     context.getMetaData().addWebInfJar(bundleRes);
                 }
                 
                 if (bundle.getHeaders().get(Constants.FRAGMENT_HOST) != null)
                 {
                     //a fragment indeed:
                     parseFragmentBundle(context,oparser,webbundle,bundle);
                 }
             }
         }
         //scan ourselves
         oparser.indexBundle(webbundle);
         parseWebBundle(context,oparser,webbundle);
         
         //scan the WEB-INF/lib
         super.parseWebInfLib(context,parser);
         if (fragAndRequiredBundles != null)
         {
             //scan the required bundles
             for (Bundle requiredBundle : fragAndRequiredBundles)
             {
                 //skip bundles that have been uninstalled since we discovered them
                 if (requiredBundle.getState() == Bundle.UNINSTALLED)
                     continue;
                 
                 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 if unable to parse fragment bundle
      */
     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
      * @throws Exception if unable to parse the web bundle
      */
     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 requiredBundle The OSGi required bundle to scan
      * @throws Exception if unable to parse the required bundle
      */
     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);  
         Set<Handler> handlers = new HashSet<Handler>();
         handlers.addAll(_discoverableAnnotationHandlers);
         if (_classInheritanceHandler != null)
             handlers.add(_classInheritanceHandler);
         handlers.addAll(_containerInitializerAnnotationHandlers);
 
         ClassNameResolver classNameResolver = createClassNameResolver(context);
         if (_parserTasks != null)
         {
             BundleParserTask task = new BundleParserTask(parser, handlers, bundleRes, classNameResolver);
             _parserTasks.add(task);
             if (LOG.isDebugEnabled())
                 task.setStatistic(new TimeStatistic());
         }
     }
     
     /**
      * Returns the same classname resolver than for the webInfjar scanner
      * @param context the web app context
      * @return the class name resolver
      */
     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;
             }
         };
     }
 
 }