/*

  * 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.web.view.impl;

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

 import com.sun.syndication.io.FeedException;

 import com.sun.syndication.io.SyndFeedOutput;

 import net.sourceforge.pebble.Constants;

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

 import net.sourceforge.pebble.decorator.ContentDecoratorChain;

 import net.sourceforge.pebble.domain.*;

 import net.sourceforge.pebble.web.view.View;

 import javax.servlet.ServletContext;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import java.io.IOException;

 import java.text.SimpleDateFormat;

 import java.util.*;

 /**

  * Abstract view from which all ROME feeds are rendered.

  *

  * @author James Roper

  */

 public abstract class AbstractRomeFeedView extends View {

   private final FeedType feedType;

   private final SimpleDateFormat idDateFormat;

   protected AbstractRomeFeedView(FeedType feedType) {

     this.feedType = feedType;

     this.idDateFormat = new SimpleDateFormat("yyyy-MM-dd");

     idDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));

   }

   /**

    * Prepares the view for presentation.

    */

   @SuppressWarnings("unchecked")

   public void prepare() {

     ContentDecoratorContext context = new ContentDecoratorContext();

     context.setView(ContentDecoratorContext.SUMMARY_VIEW);

     context.setMedia(ContentDecoratorContext.NEWS_FEED);

     List<BlogEntry> blogEntries = (List<BlogEntry>) getModel().get(Constants.BLOG_ENTRIES);

     ContentDecoratorChain.decorate(context, blogEntries);

     getModel().put(Constants.BLOG_ENTRIES, blogEntries);

   }

   /**

    * Gets the content type of this view.

    *

    * @return the content type as a String

    */

   public String getContentType() {

     AbstractBlog blog = (AbstractBlog) getModel().get(Constants.BLOG_KEY);

     return feedType.getContentType() + "; charset=" + blog.getCharacterEncoding();

   }

   /**

    * Dispatch the view using ROME

    *

    * @param request  the request

    * @param response the resopnse

    * @param context  the the servlet context

    * @throws ServletException

    */

   public void dispatch(HttpServletRequest request, HttpServletResponse response, ServletContext context) throws ServletException {

     SyndFeed syndFeed = getFeed();

     syndFeed.setFeedType(getFeedType().getFeedType());

     SyndFeedOutput output = new SyndFeedOutput();

     try {

       output.output(syndFeed, response.getWriter());

     } catch (IOException e) {

       throw new ServletException("Error generating feed", e);

     } catch (FeedException e) {

       throw new ServletException("Error generating feed", e);

     }

   }

   /**

    * Get the feed to return.

    *

    * @return The feed to return.

    */

   protected abstract SyndFeed getFeed();

   /**

    * Get the feed type for this view

    *

    * @return The feed type

    */

   public FeedType getFeedType() {

     return feedType;

   }

   protected SimpleDateFormat getIdDateFormat() {

     return idDateFormat;

   }

   protected String generateId(AbstractBlog blog, Date date, String contentId) {

     StringBuilder id = new StringBuilder("tag:");

     id.append(blog.getDomainName()).append(",");

     if (date != null) {

       id.append(getIdDateFormat().format(date));

     } else {

       id.append("0000-00-00");

     }

     id.append(":").append(blog.getId());

     if (contentId != null) {

       id.append("/").append(contentId);

     }

     return id.toString();

   }

   /**

    * The type of feed

    */

   public enum FeedType {

     ATOM("atom_1.0", "atom.xml", "application/atom+xml"),

     RSS("rss_2.0", "rss.xml", "application/xml");

     private final String feedType;

     private final String fileName;

     private final String contentType;

     FeedType(String feedType, String fileName, String contentType) {

       this.feedType = feedType;

       this.fileName = fileName;

       this.contentType = contentType;

     }

     /**

      * Get the ROME feed type, eg atom_1.0

      *

      * @return The ROME feed type

      */

     public String getFeedType() {

       return feedType;

     }

     /**

      * Get the file name that this feed uses, eg atom.xml, rss.xml

      *

      * @return The filename

      */

     public String getFileName() {

       return fileName;

     }

     /**

      * Get the content type to set when sending this feed

      *

      * @return The content type

      */

     public String getContentType() {

       return contentType;

     }

   }

 }