/*
 * Copyright 2009-2012 by KNURT Systeme (http://www.knurt.de)
 *
 * Licensed under the Creative Commons License Attribution-NonCommercial-ShareAlike 3.0 Unported;
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://creativecommons.org/licenses/by-nc-sa/3.0/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package de.knurt.fam.core.aspects.security.encoder;

import de.knurt.fam.core.model.persist.User;

/**
 * encode the main password of a user.
 * 
 * @author Daniel Oltmanns
 * @since 0.20090409 (04/09/2009)
 */
public class FamUserPassEncoderControl extends FamEncoderControl {

	/** one and only instance of me */
	private volatile static FamUserPassEncoderControl me;

	/** construct me */
	private FamUserPassEncoderControl() {
	}

	/**
	 * return the one and only instance of FamUserPassEncoderControl
	 * 
	 * @return the one and only instance of FamUserPassEncoderControl
	 */
	public static FamUserPassEncoderControl getInstance() {
		if (me == null) { // no instance so far
			synchronized (FamUserPassEncoderControl.class) {
				if (me == null) { // still no instance so far
					me = new FamUserPassEncoderControl(); // the one and only
				}
			}
		}
		return me;
	}

	/**
	 * encode the password. only encode, if user password is not already
	 * encoded! do not set it as users password! use
	 * {@link User#encodePassword()} instead!
	 * 
	 * @see User#encodePassword()
	 * @param user
	 *            the password shall be encoded.
	 * @return the encoded password.
	 */
	@Override
	public String encodePassword(User user) {
		String result = user.getPassword();
		if (user.isPasswordEncoded() == false) {
			result = super.encodePassword(user);
		}
		return result;
	}

	/**
	 * no salt here.
	 * 
	 * @param user
	 *            the encoded password is for
	 * @return null for not using a salt here
	 */
	@Override
	protected Object getSalt(User user) {
		return null;
	}
}