/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.wicket.authentication;

import org.apache.wicket.Application;

/**
 * The interface of an authentication strategy which is accessible via
 * {@link Application#getSecuritySettings()}. Implementations determine how logon data (username and
 * password) are persisted (e.g. Cookie), retrieved and removed.
 * 
 * @author Juergen Donnerstag
 */
public interface IAuthenticationStrategy
{
	/**
	 * If "rememberMe" is enabled, then load the saved credentials (e.g. username and password) from the persistence storage
	 * (e.g. Cookie) for automatic sign in. This is useful for applications which users typically
	 * have open the whole day but where the server invalidates the session after a timeout and you
	 * want to force the user to sign in again and again during the day.
	 * 
	 * @return The {@link #save(String, String...) saved} credentials
	 */
	String[] load();

	/**
	 * If "rememberMe" is enabled and login was successful, then store the given credentials in the
	 * persistence store (e.g. Cookie).
	 *
	 * <p>The implementation of this method should be symmetrical with the implementation of
	 * {@link #load()}.</p>
	 *
	 * @param credential
	 *          The credential to store. For example: a security token or username.
	 * @param extraCredentials
	 *          Optional extra credentials. For example: a password
	 */
	void save(final String credential, final String... extraCredentials);

	/**
	 * When the user logs out (session invalidation), than remove username and password from the
	 * persistence store
	 */
	void remove();
}