/*

 *   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 org.sonews.storage.Article;

import org.sonews.daemon.NNTPConnection;

import org.sonews.storage.Channel;

import org.sonews.storage.StorageBackendException;

/**

 * Class handling the ARTICLE, BODY and HEAD commands.

 * @author Christian Lins

 * @author Dennis Schwerdel

 * @since n3tpd/0.1

 */

public class ArticleCommand implements Command

{

  @Override

  public String[] getSupportedCommandStrings()

  {

    return new String[] {"ARTICLE", "BODY", "HEAD"};

  }

  @Override

  public boolean hasFinished()

  {

    return true;

  }

  @Override

  public String impliedCapability()

  {

    return null;

  }

  @Override

  public boolean isStateful()

  {

    return false;

  }

  // TODO: Refactor this method to reduce its complexity!

  @Override

  public void processLine(NNTPConnection conn, final String line, byte[] raw)

    throws IOException

  {

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

    Article article  = null;

    long    artIndex = -1;

    if (command.length == 1)

    {

      article = conn.getCurrentArticle();

      if (article == null)

      {

        conn.println("420 no current article has been selected");

        return;

      }

    }

    else if (command[1].matches(NNTPConnection.MESSAGE_ID_PATTERN))

    {

      // Message-ID

      article = Article.getByMessageID(command[1]);

      if (article == null)

      {

        conn.println("430 no such article found");

        return;

      }

    }

    else

    {

      // Message Number

      try

      {

        Channel currentGroup = conn.getCurrentChannel();

        if(currentGroup == null)

        {

          conn.println("400 no group selected");

          return;

        }

        artIndex = Long.parseLong(command[1]);

        article  = currentGroup.getArticle(artIndex);

      }

      catch(NumberFormatException ex)

      {

        ex.printStackTrace();

      }

      catch(StorageBackendException ex)

      {

        ex.printStackTrace();

      }

      if (article == null)

      {

        conn.println("423 no such article number in this group");

        return;

      }

      conn.setCurrentArticle(article);

    }

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

    {

      conn.println("220 " + artIndex + " " + article.getMessageID()

          + " article retrieved - head and body follow");

      conn.println(article.getHeaderSource());

      conn.println("");

      conn.println(article.getBody());

      conn.println(".");

    }

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

    {

      conn.println("222 " + artIndex + " " + article.getMessageID() + " body");

      conn.println(article.getBody());

      conn.println(".");

    }

    /*

     * HEAD: This command is mandatory.

     *

     * Syntax

     *    HEAD message-id

     *    HEAD number

     *    HEAD

     *

     * Responses

     *

     * First form (message-id specified)

     *  221 0|n message-id    Headers follow (multi-line)

     *  430                   No article with that message-id

     *

     * Second form (article number specified)

     *  221 n message-id      Headers follow (multi-line)

     *  412                   No newsgroup selected

     *  423                   No article with that number

     *

     * Third form (current article number used)

     *  221 n message-id      Headers follow (multi-line)

     *  412                   No newsgroup selected

     *  420                   Current article number is invalid

     *

     * Parameters

     *  number        Requested article number

     *  n             Returned article number

     *  message-id    Article message-id

     */

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

    {

      conn.println("221 " + artIndex + " " + article.getMessageID()

          + " Headers follow (multi-line)");

      conn.println(article.getHeaderSource());

      conn.println(".");

    }

  }  

}