/*
 * 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.shiro.web.tags;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * JSP tag that renders the tag body only if the current user has executed a <b>successful</b> authentication attempt
 * <em>during their current session</em>.
 *
 * <p>This is more restrictive than the {@link UserTag}, which only
 * ensures the current user is known to the system, either via a current login or from Remember Me services,
 * which only makes the assumption that the current user is who they say they are, and does not guarantee it like
 * this tag does.
 *
 * <p>The logically opposite tag of this one is the {@link NotAuthenticatedTag}
 *
 * @since 0.2
 */
public class AuthenticatedTag extends SecureTag {

    private static final Logger LOGGER = LoggerFactory.getLogger(AuthenticatedTag.class);

    public int onDoStartTag() throws JspException {
        if (getSubject() != null && getSubject().isAuthenticated()) {
            if (LOGGER.isTraceEnabled()) {
                LOGGER.trace("Subject exists and is authenticated.  Tag body will be evaluated.");
            }
            return TagSupport.EVAL_BODY_INCLUDE;
        } else {
            if (LOGGER.isTraceEnabled()) {
                LOGGER.trace("Subject does not exist or is not authenticated.  Tag body will not be evaluated.");
            }
            return TagSupport.SKIP_BODY;
        }
    }
}
