/*

 *   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.config.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.inst().get(Config.MLPOLL_USER, "user");

			final String password =

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

			return new PasswordAuthentication(username, password);

		}

	}

	@Override

	public void run()

	{

		Log.get().info("Starting Mailinglist Poller...");

		int errors = 0;

		while (isRunning()) {

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

				final String username =

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

				final String password =

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

				Stats.getInstance().mlgwRunStart();

				// Create empty properties

				Properties props = System.getProperties();

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

				props.put("mail.mime.address.strict", "false");

				// 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) {

					if (Dispatcher.toGroup(message)

						|| Config.inst().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.get().severe(ex.toString());

				shutdown();

			} catch (AuthenticationFailedException ex) {

				// AuthentificationFailedException may be thrown if credentials are

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

				ex.printStackTrace();

				errors = errors < 5 ? errors + 1 : errors;

			} catch (InterruptedException ex) {

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

				return;

			} catch (MessagingException ex) {

				ex.printStackTrace();

				errors = errors < 5 ? errors + 1 : errors;

			} catch (Exception ex) {

				ex.printStackTrace();

				errors = errors < 5 ? errors + 1 : errors;

			}

		}

		Log.get().severe("MailPoller exited.");

	}

}