/*
 * Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
 *
 * 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
 *
 *      https://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.springframework.security.web.authentication.logout;

import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jspecify.annotations.Nullable;

import org.springframework.core.log.LogMessage;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContext;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.context.SecurityContextHolderStrategy;
import org.springframework.security.web.context.HttpSessionSecurityContextRepository;
import org.springframework.security.web.context.SecurityContextRepository;
import org.springframework.util.Assert;

/**
 * Performs a logout by modifying the
 * {@link org.springframework.security.core.context.SecurityContextHolder}.
 * <p>
 * Will also invalidate the {@link HttpSession} if {@link #isInvalidateHttpSession()} is
 * {@code true} and the session is not {@code null}.
 * <p>
 * Will also remove the {@link Authentication} from the current {@link SecurityContext} if
 * {@link #clearAuthentication} is set to true (default).
 *
 * @author Ben Alex
 * @author Rob Winch
 */
public class SecurityContextLogoutHandler implements LogoutHandler {

	protected final Log logger = LogFactory.getLog(this.getClass());

	private SecurityContextHolderStrategy securityContextHolderStrategy = SecurityContextHolder
		.getContextHolderStrategy();

	private boolean invalidateHttpSession = true;

	private boolean clearAuthentication = true;

	private SecurityContextRepository securityContextRepository = new HttpSessionSecurityContextRepository();

	/**
	 * Requires the request to be passed in.
	 * @param request from which to obtain a HTTP session (cannot be null)
	 * @param response not used (can be <code>null</code>)
	 * @param authentication not used (can be <code>null</code>)
	 */
	@Override
	public void logout(HttpServletRequest request, HttpServletResponse response,
			@Nullable Authentication authentication) {
		Assert.notNull(request, "HttpServletRequest required");
		if (this.invalidateHttpSession) {
			HttpSession session = request.getSession(false);
			if (session != null) {
				session.invalidate();
				if (this.logger.isDebugEnabled()) {
					this.logger.debug(LogMessage.format("Invalidated session %s", session.getId()));
				}
			}
		}
		SecurityContext context = this.securityContextHolderStrategy.getContext();
		this.securityContextHolderStrategy.clearContext();
		if (this.clearAuthentication) {
			context.setAuthentication(null);
		}
		SecurityContext emptyContext = this.securityContextHolderStrategy.createEmptyContext();
		this.securityContextRepository.saveContext(emptyContext, request, response);
	}

	public boolean isInvalidateHttpSession() {
		return this.invalidateHttpSession;
	}

	/**
	 * Sets the {@link SecurityContextHolderStrategy} to use. The default action is to use
	 * the {@link SecurityContextHolderStrategy} stored in {@link SecurityContextHolder}.
	 *
	 * @since 5.8
	 */
	public void setSecurityContextHolderStrategy(SecurityContextHolderStrategy securityContextHolderStrategy) {
		Assert.notNull(securityContextHolderStrategy, "securityContextHolderStrategy cannot be null");
		this.securityContextHolderStrategy = securityContextHolderStrategy;
	}

	/**
	 * Causes the {@link HttpSession} to be invalidated when this {@link LogoutHandler} is
	 * invoked. Defaults to true.
	 * @param invalidateHttpSession true if you wish the session to be invalidated
	 * (default) or false if it should not be.
	 */
	public void setInvalidateHttpSession(boolean invalidateHttpSession) {
		this.invalidateHttpSession = invalidateHttpSession;
	}

	/**
	 * If true, removes the {@link Authentication} from the {@link SecurityContext} to
	 * prevent issues with concurrent requests.
	 * @param clearAuthentication true if you wish to clear the {@link Authentication}
	 * from the {@link SecurityContext} (default) or false if the {@link Authentication}
	 * should not be removed.
	 */
	public void setClearAuthentication(boolean clearAuthentication) {
		this.clearAuthentication = clearAuthentication;
	}

	/**
	 * Sets the {@link SecurityContextRepository} to use. Default is
	 * {@link HttpSessionSecurityContextRepository}.
	 * @param securityContextRepository the {@link SecurityContextRepository} to use.
	 */
	public void setSecurityContextRepository(SecurityContextRepository securityContextRepository) {
		Assert.notNull(securityContextRepository, "securityContextRepository cannot be null");
		this.securityContextRepository = securityContextRepository;
	}

}
