/**
 * $RCSfile$
 * $Revision: $
 * $Date: $
 *
 * Copyright 2003-2007 Jive Software.
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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 org.jivesoftware.smack;

import javax.security.auth.callback.CallbackHandler;

/**
 * There are two ways to authenticate a user with a server. Using SASL or
 * Non-SASL authentication. This interface makes {@link SASLAuthentication} and
 * {@link NonSASLAuthentication} polyphormic.
 * 
 * @author Gaston Dombiak
 * @author Jay Kline
 */
interface UserAuthentication {

	/**
	 * Authenticates the user with the server. This method will return the full
	 * JID provided by the server. The server may assign a full JID with a
	 * username and resource different than requested by this method.
	 * 
	 * Note that using callbacks is the prefered method of authenticating users
	 * since it allows more flexability in the mechanisms used.
	 * 
	 * @param username
	 *            the requested username (authorization ID) for authenticating
	 *            to the server
	 * @param resource
	 *            the requested resource.
	 * @param cbh
	 *            the CallbackHandler used to obtain authentication ID,
	 *            password, or other information
	 * @return the full JID provided by the server while binding a resource for
	 *         the connection.
	 * @throws XMPPException
	 *             if an error occurs while authenticating.
	 */
	String authenticate(String username, String resource, CallbackHandler cbh)
			throws XMPPException;

	/**
	 * Authenticates the user with the server. This method will return the full
	 * JID provided by the server. The server may assign a full JID with a
	 * username and resource different than the requested by this method.
	 * 
	 * It is recommended that @{link #authenticate(String, String,
	 * CallbackHandler)} be used instead since it provides greater flexability
	 * in authenticaiton and authorization.
	 * 
	 * @param username
	 *            the username that is authenticating with the server.
	 * @param password
	 *            the password to send to the server.
	 * @param resource
	 *            the desired resource.
	 * @return the full JID provided by the server while binding a resource for
	 *         the connection.
	 * @throws XMPPException
	 *             if an error occures while authenticating.
	 */
	String authenticate(String username, String password, String resource)
			throws XMPPException;

	/**
	 * Performs an anonymous authentication with the server. The server will
	 * created a new full JID for this connection. An exception will be thrown
	 * if the server does not support anonymous authentication.
	 * 
	 * @return the full JID provided by the server while binding a resource for
	 *         the connection.
	 * @throws XMPPException
	 *             if an error occures while authenticating.
	 */
	String authenticateAnonymously() throws XMPPException;
}