/*

 *   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.acl;

import java.io.IOException;

import java.util.Arrays;

import java.util.logging.Level;

import java.util.logging.Logger;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import org.sonews.daemon.NNTPConnection;

import org.sonews.daemon.command.Command;

import org.sonews.storage.StorageBackendException;

import org.sonews.storage.StorageManager;

/**

 *

 * @author František Kučera (frantovo.cz)

 */

public class AuthInfoCommand implements Command {

	private static final Logger log = Logger.getLogger(AuthInfoCommand.class.getName());

	private static String[] SUPPORTED_COMMANDS = {"AUTHINFO"};

	@Override

	public boolean hasFinished() {

		return true;

	}

	@Override

	public String impliedCapability() {

		return "AUTHINFO";

	}

	@Override

	public boolean isStateful() {

		// TODO: make it statefull?

		return false;

	}

	@Override

	public String[] getSupportedCommandStrings() {

		return SUPPORTED_COMMANDS;

	}

	@Override

	public void processLine(NNTPConnection conn, String line, byte[] rawLine) throws IOException, StorageBackendException {

		Pattern commandPattern = Pattern.compile("AUTHINFO (USER|PASS) (.*)", Pattern.CASE_INSENSITIVE);

		Matcher commandMatcher = commandPattern.matcher(line);

		if (commandMatcher.matches()) {

			if (conn.getUser() != null && conn.getUser().isAuthenticated()) {

				conn.println("502 Command unavailable (you are already authenticated)");

			} else if ("USER".equalsIgnoreCase(commandMatcher.group(1))) {

				conn.setUser(new User(commandMatcher.group(2)));

				conn.println("381 Password required"); // ask user for his password

				log.log(Level.FINE, "User ''{0}'' greets us. We are waiting for his password.", conn.getUser().getUserName());

			} else if ("PASS".equalsIgnoreCase(commandMatcher.group(1))) {

				if (conn.getUser() == null) {

					conn.println("482 Authentication commands issued out of sequence");

				} else {

					char[] password = commandMatcher.group(2).toCharArray();

					// TODO: StorageManager should return User object instead of boolean (so there could be transferred some additional information about user)

					boolean goodPassword = StorageManager.current().authenticateUser(conn.getUser().getUserName(), password);

					Arrays.fill(password, '*');

					commandMatcher = null;

					if (goodPassword) {

						conn.println("281 Authentication accepted");

						conn.getUser().setAuthenticated(true);

						log.log(Level.INFO, "User ''{0}'' has been succesfully authenticated.", conn.getUser().getUserName());

					} else {

						log.log(Level.INFO, "User ''{0}'' has provided wrong password.", conn.getUser().getUserName());

						conn.setUser(null);

						conn.println("481 Authentication failed: wrong password");

					}

				}

			} else {

				// impossible, see commandPattern

				conn.println("500 Unknown command");

			}

		} else {

			conn.println("500 Unknown command, expecting AUTHINFO USER username or AUTHINFO PASS password ");

		}

	}

}