/*

  *   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.mlgw;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.List;

 import javax.mail.Address;

 import javax.mail.Authenticator;

 import javax.mail.Message;

 import javax.mail.MessagingException;

 import javax.mail.PasswordAuthentication;

 import javax.mail.internet.InternetAddress;

 import org.sonews.config.Config;

 import org.sonews.storage.Article;

 import org.sonews.storage.Headers;

 import org.sonews.storage.StorageBackendException;

 import org.sonews.storage.StorageManager;

 import org.sonews.util.Log;

 import org.sonews.util.Stats;

 /**

  * Dispatches messages from mailing list or newsserver or vice versa.

  * @author Christian Lins

  * @since sonews/0.5.0

  */

 public class Dispatcher 

 {

   static class PasswordAuthenticator extends Authenticator

   {

     @Override

     public PasswordAuthentication getPasswordAuthentication()

     {

       final String username = 

         Config.inst().get(Config.MLSEND_USER, "user");

       final String password = 

         Config.inst().get(Config.MLSEND_PASSWORD, "mysecret");

       return new PasswordAuthentication(username, password);

     }

   }

   /**

    * Posts a message that was received from a mailing list to the 

    * appropriate newsgroup.

    * @param msg

    */

   public static boolean toGroup(final Message msg)

   {

     try

     {

       Address[] to = msg.getAllRecipients(); // includes TO/CC/BCC

       if(to == null || to.length <= 0)

       {

         to = msg.getReplyTo();

       }

       if(to == null || to.length <= 0)

       {

         Log.msg("Skipping message because no recipient!", false);

         return false;

       }

       else

       {

         boolean      posted     = false;

         List<String> newsgroups = new ArrayList<String>();

         for (Address toa : to) // Address can have '<' '>' around

         {

           if (toa instanceof InternetAddress)

           {

             List<String> groups = StorageManager.current()

               .getGroupsForList((InternetAddress)toa);

             newsgroups.addAll(groups);

           }

         }

         if (newsgroups.size() > 0)

         {

           StringBuilder groups = new StringBuilder();

           for(int n = 0; n < newsgroups.size(); n++)

           {

             groups.append(newsgroups.get(n));

             if(n + 1 != newsgroups.size())

             {

               groups.append(',');

             }

           }

           Log.msg("Posting to group " + groups.toString(), true);

           // Create new Article object

           Article article = new Article(msg);

           article.setGroup(groups.toString());

           article.removeHeader(Headers.REPLY_TO);

           article.removeHeader(Headers.TO);

           // Write article to database

           if(!StorageManager.current().isArticleExisting(article.getMessageID()))

           {

             StorageManager.current().addArticle(article);

             Stats.getInstance().mailGatewayed(

               article.getHeader(Headers.NEWSGROUPS)[0]);

           }

           else

           {

             Log.msg("Article " + article.getMessageID() + " already existing.", true);

           }

           posted = true;

         }

         else

         {

           StringBuilder buf = new StringBuilder();

           for(Address toa : to)

           {

             buf.append(' ');

             buf.append(toa.toString());

           }

           Log.msg("No group for" + buf.toString(), false);

         }

         return posted;

       }

     }

     catch(Exception ex)

     {

       ex.printStackTrace();

       return false;

     }

   }

   /**

    * Mails a message received through NNTP to the appropriate mailing list.

    */

   public static void toList(Article article)

     throws IOException, MessagingException, StorageBackendException

   {

     // Get mailing lists for the group of this article

     List<String> listAddresses = new ArrayList<String>();

     String[]     groupnames    = article.getHeader(Headers.NEWSGROUPS)[0].split(",");

     for(String groupname : groupnames)

     {

       String listAddress = StorageManager.current().getListForGroup(groupname);

       if(listAddress != null)

       {

         listAddresses.add(listAddress);

       }

     }

     for(String listAddress : listAddresses)

     {

       // Compose message and send it via given SMTP-Host

       String smtpHost = Config.inst().get(Config.MLSEND_HOST, "localhost");

       int    smtpPort = Config.inst().get(Config.MLSEND_PORT, 25);

       String smtpUser = Config.inst().get(Config.MLSEND_USER, "user");

       String smtpPw   = Config.inst().get(Config.MLSEND_PASSWORD, "mysecret");

       String smtpFrom = Config.inst().get(

           Config.MLSEND_ADDRESS, article.getHeader(Headers.FROM)[0]);

       // TODO: Make Article cloneable()

       String group = article.getHeader(Headers.NEWSGROUPS)[0];

       article.getMessageID(); // Make sure an ID is existing

       article.removeHeader(Headers.NEWSGROUPS);

       article.removeHeader(Headers.PATH);

       article.removeHeader(Headers.LINES);

       article.removeHeader(Headers.BYTES);

       article.setHeader("To", listAddress);

       article.setHeader("Reply-To", listAddress);

       if(Config.inst().get(Config.MLSEND_RW_SENDER, false))

       {

         rewriteSenderAddress(article); // Set the SENDER address

       }

       SMTPTransport smtpTransport = new SMTPTransport(smtpHost, smtpPort);

       smtpTransport.send(article, smtpFrom, listAddress);

       smtpTransport.close();

       Stats.getInstance().mailGatewayed(group);

       Log.msg("MLGateway: Mail " + article.getHeader("Subject")[0] 

         + " was delivered to " + listAddress + ".", true);

     }

   }

   /**

    * Sets the SENDER header of the given MimeMessage. This might be necessary

    * for moderated groups that does not allow the "normal" FROM sender.

    * @param msg

    * @throws javax.mail.MessagingException

    */

   private static void rewriteSenderAddress(Article msg)

     throws MessagingException

   {

     String mlAddress = Config.inst().get(Config.MLSEND_ADDRESS, null);

     if(mlAddress != null)

     {

       msg.setHeader(Headers.SENDER, mlAddress);

     }

     else

     {

       throw new MessagingException("Cannot rewrite SENDER header!");

     }

   }

 }