/*

 *   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.util.Properties;

import javax.mail.AuthenticationFailedException;

import javax.mail.Authenticator;

import javax.mail.Flags.Flag;

import javax.mail.Folder;

import javax.mail.Message;

import javax.mail.MessagingException;

import javax.mail.NoSuchProviderException;

import javax.mail.PasswordAuthentication;

import javax.mail.Session;

import javax.mail.Store;

import org.sonews.daemon.Config;

import org.sonews.daemon.AbstractDaemon;

import org.sonews.util.Log;

import org.sonews.util.Stats;

/**

 * Daemon polling for new mails in a POP3 account to be delivered to newsgroups.

 * @author Christian Lins

 * @since sonews/0.5.0

 */

public class MailPoller extends AbstractDaemon

{

  static class PasswordAuthenticator extends Authenticator

  {

    @Override

    public PasswordAuthentication getPasswordAuthentication()

    {

      final String username = 

        Config.getInstance().get(Config.MLPOLL_USER, "user");

      final String password = 

        Config.getInstance().get(Config.MLPOLL_PASSWORD, "mysecret");

      return new PasswordAuthentication(username, password);

    }

  }

  @Override

  public void run()

  {

    Log.msg("Starting Mailinglist Poller...", false);

    int errors = 0;

    while(isRunning() && errors < 5)

    {

      try

      {

        // Wait some time between runs. At the beginning has advantages,

        // because the wait is not skipped if an exception occurs.

        Thread.sleep(60000 * (errors + 1)); // one minute * errors

        final String host     = 

          Config.getInstance().get(Config.MLPOLL_HOST, "samplehost");

        final String username = 

          Config.getInstance().get(Config.MLPOLL_USER, "user");

        final String password = 

          Config.getInstance().get(Config.MLPOLL_PASSWORD, "mysecret");

        Stats.getInstance().mlgwRunStart();

        // Create empty properties

        Properties props = System.getProperties();

        props.put("mail.pop3.host", host);

        // Get session

        Session session = Session.getInstance(props);

        // Get the store

        Store store = session.getStore("pop3");

        store.connect(host, 110, username, password);

        // Get folder

        Folder folder = store.getFolder("INBOX");

        folder.open(Folder.READ_WRITE);

        // Get directory

        Message[] messages = folder.getMessages();

        // Dispatch messages and delete it afterwards on the inbox

        for(Message message : messages)

        {

          String subject = message.getSubject();

          System.out.println("MLGateway: message with subject \"" + subject + "\" received.");

          if(Dispatcher.toGroup(message)

            || Config.getInstance().get(Config.MLPOLL_DELETEUNKNOWN, false))

          {

            // Delete the message

            message.setFlag(Flag.DELETED, true);

          }

        }

        // Close connection 

        folder.close(true); // true to expunge deleted messages

        store.close();

        errors = 0;

        Stats.getInstance().mlgwRunEnd();

      }

      catch(NoSuchProviderException ex)

      {

        Log.msg(ex.toString(), false);

        shutdown();

      }

      catch(AuthenticationFailedException ex)

      {

        // AuthentificationFailedException may be thrown if credentials are

        // bad or if the Mailbox is in use (locked).

        ex.printStackTrace();

        errors++;

      }

      catch(InterruptedException ex)

      {

        System.out.println("sonews: " + this + " returns.");

        return;

      }

      catch(MessagingException ex)

      {

        ex.printStackTrace();

        errors++;

      }

      catch(Exception ex)

      {

        ex.printStackTrace();

        errors++;

      }

    }

    Log.msg("MailPoller exited.", false);

  }

}