/*

  *   SONEWS News Server

  *   see AUTHORS for the list of contributors

  *

  *   This program is free software: you can redistribute it and/or modify

  *   it under the terms of the GNU General Public License as published by

  *   the Free Software Foundation, either version 3 of the License, or

  *   (at your option) any later version.

  *

  *   This program is distributed in the hope that it will be useful,

  *   but WITHOUT ANY WARRANTY; without even the implied warranty of

  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  *   GNU General Public License for more details.

  *

  *   You should have received a copy of the GNU General Public License

  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.

  */

 package org.sonews.daemon.command;

 import java.io.IOException;

 import java.sql.SQLException;

 import org.sonews.daemon.NNTPConnection;

 import org.sonews.daemon.storage.Article;

 import org.sonews.daemon.storage.Group;

 /**

  * Class handling the NEXT and LAST command.

  * @author Christian Lins

  * @author Dennis Schwerdel

  * @since n3tpd/0.1

  */

 public class NextPrevCommand extends AbstractCommand

 {

   public NextPrevCommand(final NNTPConnection conn)

   {

     super(conn);

   }

   @Override

   public boolean hasFinished()

   {

     return true;

   }

   @Override

   public void processLine(final String line)

     throws IOException, SQLException

   {

     final Article currA = getCurrentArticle();

     final Group   currG = getCurrentGroup();

     if (currA == null)

     {

       printStatus(420, "no current article has been selected");

       return;

     }

     if (currG == null)

     {

       printStatus(412, "no newsgroup selected");

       return;

     }

     final String[] command = line.split(" ");

     if(command[0].equalsIgnoreCase("NEXT"))

     {

       selectNewArticle(currA, currG, 1);

     }

     else if(command[0].equalsIgnoreCase("PREV"))

     {

       selectNewArticle(currA, currG, -1);

     }

     else

     {

       printStatus(500, "internal server error");

     }

   }

   private void selectNewArticle(Article article, Group grp, final int delta)

     throws IOException, SQLException

   {

     assert article != null;

     article = Article.getByArticleNumber(article.getIndexInGroup(grp) + delta, grp);

     if(article == null)

     {

       printStatus(421, "no next article in this group");

     }

     else

     {

       setCurrentArticle(article);

       printStatus(223, article.getIndexInGroup(getCurrentGroup()) + " " + article.getMessageID() + " article retrieved - request text separately");

     }

   }

 }