/*

  * Copyright (c) 2003-2011, Simon Brown

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are met:

  *

  *   - Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  *

  *   - Redistributions in binary form must reproduce the above copyright

  *     notice, this list of conditions and the following disclaimer in

  *     the documentation and/or other materials provided with the

  *     distribution.

  *

  *   - Neither the name of Pebble nor the names of its contributors may

  *     be used to endorse or promote products derived from this software

  *     without specific prior written permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

  * POSSIBILITY OF SUCH DAMAGE.

  */

 package net.sourceforge.pebble.decorator;

 import com.sun.syndication.feed.synd.SyndEntry;

 import com.sun.syndication.feed.synd.SyndFeed;

 import com.sun.syndication.feed.synd.SyndLink;

 import com.sun.syndication.feed.synd.SyndLinkImpl;

 import net.sourceforge.pebble.api.decorator.FeedDecorator;

 import net.sourceforge.pebble.domain.Blog;

 import net.sourceforge.pebble.domain.BlogEntry;

 import net.sourceforge.pebble.domain.Response;

 import net.sourceforge.pebble.event.blogentry.PubSubHubBubBlogEntryListener;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import java.util.*;

 /**

  * Adds hub links to the feed, implementing the discovery part of pubsubhubbub

  *

  * @author James Roper

  */

 public class PubSubHubBubFeedDecorator implements FeedDecorator {

   private static final Log log = LogFactory.getLog(PubSubHubBubFeedDecorator.class);

   public static final String HUBS_PROPERTY = "pubsubhubbub.hubs";

   private volatile Boolean listenerEnabled;

   public void decorate(SyndFeed feed, Blog blog) {

     if (checkListenerEnabled(blog)) {

       List<SyndLink> links = new ArrayList<SyndLink>(feed.getLinks());

       for (String hub : getHubs(blog)) {

         SyndLink link = new SyndLinkImpl();

         link.setRel("hub");

         link.setHref(hub.trim());

         links.add(link);

       }

       feed.setLinks(links);

     } else {

       log.warn("PubSubHubBub Feed Decorator plugin is enabled, however the PubSubHubBub " +

           "blog entry listener does not appeared to be enabled. Not adding hub to feed, " +

           "otherwise aggregators will never get updates.");

     }

   }

   public void decorate(SyndFeed feed, Blog blog, BlogEntry blogEntry) {

     // We don't use hubs for response feeds

   }

   public void decorate(SyndEntry entry, Blog blog, BlogEntry blogEntry) {

   }

   public void decorate(SyndEntry entry, Blog blog, Response response) {

     // We don't use hubs for response feeds

   }

   private boolean checkListenerEnabled(Blog blog) {

     return blog.getBlogEntryListeners().contains(PubSubHubBubBlogEntryListener.class.getName());

   }

   private Collection<String> getHubs(Blog blog) {

     String hubs = blog.getPluginProperties().getProperty(HUBS_PROPERTY);

     if (hubs == null || hubs.length() == 0) {

       return Collections.emptyList();

     }

     return Arrays.asList(hubs.split(","));

   }

 }