/*

  * 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.event.blogentry;

 import java.io.BufferedReader;

 import java.io.IOException;

 import java.io.InputStreamReader;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.net.URLConnection;

 import net.sourceforge.pebble.PluginProperties;

 import net.sourceforge.pebble.api.event.blogentry.BlogEntryEvent;

 import net.sourceforge.pebble.api.event.blogentry.BlogEntryListener;

 import net.sourceforge.pebble.domain.Blog;

 import net.sourceforge.pebble.domain.BlogEntry;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import twitter4j.Twitter;

 /**

  * Post new blog entries to twitter.

  * This class is based on a patch by Steve Carton (PEBBLE-15), but changes it to use the

  * pebble plugin mechanism by implementing the {@link BlogEntryListener} interface

  * 

  * @author Steve Carton, Olaf Kock

  */

 public class PostToTwitterBlogEntryListener extends BlogEntryListenerSupport {

         /** the log used by this class */

         private static final Log log = LogFactory

                         .getLog(PostToTwitterBlogEntryListener.class);

         private static final String DEFAULT_TWEET_URL="https://twitter.com/";

         /**

          * Called when a blog entry has been published.

          * 

          * @param event

          *            a BlogEntryEvent instance

          */

         public void blogEntryPublished(BlogEntryEvent event) {

                 BlogEntry blogEntry = event.getBlogEntry();

                 String twitterUsername = getTwitterUsername(blogEntry);

                 String twitterPassword = getTwitterPassword(blogEntry);

                 String twitterUrl = getTwitterUrl(blogEntry);

                 if(twitterUsername == null || twitterPassword == null) {

                         blogEntry.getBlog().error("Please configure twitter credentials in order to post to twitter");

                         return;

                 }

                 String longUrl = blogEntry.getLocalPermalink();

 //                if(!checkUrl(longUrl)) {

 //                        blogEntry.getBlog().error("cowardly refusing to post url '" + longUrl + "' to twitter");

 //                        return;

 //                }

                 String tinyUrl = makeTinyURL(longUrl);

                 if (tinyUrl.equalsIgnoreCase("error"))

                         tinyUrl = longUrl;

                 String msg = composeMessage(blogEntry.getTitle(), longUrl, tinyUrl);

                 try {

                         if(getProperty(blogEntry, "simulate") != null) {

                                 blogEntry.getBlog().info("Found property 'twitter.simulate' - This would have been posted to twitter with username '" + twitterUsername + "':\n" + msg);

                         } else {

                                 post(twitterUrl, twitterUsername, twitterPassword, msg);

                         }

                 } catch (Exception e) {

                         e.printStackTrace();

                 }

                 log.debug("Blog entry <a href=\"" + longUrl

                                 + "\">" + blogEntry.getTitle() + "</a> tweeted.");

         }

         /**

          * make sure that the url we are about to post is one that makes sense to post - e.g. don't post 'localhost' urls.

          * @param longUrl

          * @return true if the url passes the (simple) tests and may be posted

          */

         boolean checkUrl(String longUrl) {

                 return ! (longUrl.contains("://localhost:") || longUrl.contains("://localhost/"));

         }

         /**

          * combine message with url. This will use longUrl when enough characters are left, tinyUrl otherwise.

          * If necessary, the title will be shortened in order to include the full URL

          * @param title

          * @param longUrl

          * @param tinyUrl

          * @return the "up to 140 character" message to post to twitter

          */

         String composeMessage(String title, String longUrl, String tinyUrl) {

                 if(longUrl.length() + title.length() > 139 ) {

                         if(tinyUrl.length() + title.length() > 139) {

                                 return title.substring(0, 139-tinyUrl.length()) + " " + tinyUrl;

                         } else {

                                 return title + " " + tinyUrl;

                         }

                 } else {

                         return title + " " + longUrl ;

                 }

         }

         /**

          * get twitter URL to post to. This can be overridden with the blog property twitter.url - e.g. for testing purposes.

          * @param blogEntry

          * @return

          */

         private String getTwitterUrl(BlogEntry blogEntry) {

                 String twitterUrl = getProperty(blogEntry, "url");

                 if(twitterUrl == null) twitterUrl = DEFAULT_TWEET_URL;

                 return twitterUrl;

         }

         /**

          * the password to post to twitter as configured in the blog properties

          * @param blogEntry

          * @return

          */

         private String getTwitterPassword(BlogEntry blogEntry) {

                 return getProperty(blogEntry, "password");

         }

         /**

          * the username to post to twitter as configured in the blog properties

          * @param blogEntry

          * @return

          */

         private String getTwitterUsername(BlogEntry blogEntry) {

                 return getProperty(blogEntry, "username");

         }

         private String getProperty(BlogEntry blogEntry, String property) {

                 Blog blog = blogEntry.getBlog();

                 String blogName = blog.getName();

                 PluginProperties pluginProperties = blog.getPluginProperties();

                 String result = pluginProperties.getProperty("twitter." + blogName + "." + property);

                 if(result == null) {

                         result = pluginProperties.getProperty("twitter." + property);

                         if(result == null) {

                                 log.error("Twitter credentials (" + property + ") not found. Please configure twitter." + property + " in order to post to twitter");

                         } else {

                                 log.debug("found twitter credentials in twitter." + property );

                         }

                 } else {

                         log.debug("found twitter credentials in twitter." + blogName + "." + property);

                 }

                 return result;

         }

         /**

          * Post the given message to twitter, using the given postUrl and credentials.

          * @param twitterUrl URL to post to

          * @param twitterUsername username to post as

          * @param twitterPassword password to authenticate username

          * @param msg the message to post to twitter.

          * @throws Exception

          */

         private void post(String twitterUrl, String twitterUsername,

                         String twitterPassword, String msg) throws Exception {

                 System.out.println("Posting to Twitter: " + msg);

                 Twitter twitter = new Twitter(twitterUsername, twitterPassword, twitterUrl);

                 twitter.updateStatus(msg);

         }

         /**

          * create a shortened version of the given url

          * @param url

          * @return

          */

         private String makeTinyURL(String url) {

                 // http://tinyurl.com/api-create.php?...

                 StringBuffer response = new StringBuffer();

                 try {

                         URL turl = new URL("http://tinyurl.com/api-create.php?"+url);

                         URLConnection connection = turl.openConnection();

                         connection.setDoInput(true);

                         connection.setDoOutput(false);

                         connection.setUseCaches(false);

                         BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));

                         String r;

                         while ((r = in.readLine()) != null) {

                                 response.append(r);

                         }

                         in.close();

                 }

                 catch (MalformedURLException e) {

                         log.error(e.getMessage());

                         return url;

                 }

                 catch (IOException e) {

                         log.error(e.getMessage());

                         return url;

                 }

                 log.debug("tinyurl for " + url + " is " + response.toString());

                 return response.toString();

         }

 }