/*

  * 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.authz.aop;

 import org.apache.shiro.authz.AuthorizationException;

 import org.apache.shiro.authz.annotation.Logical;

 import org.apache.shiro.authz.annotation.RequiresRoles;

 import java.lang.annotation.Annotation;

 import java.util.Arrays;

 /**

  * Checks to see if a @{@link org.apache.shiro.authz.annotation.RequiresRoles RequiresRoles} annotation is declared, and if so, performs

  * a role check to see if the calling <code>Subject</code> is allowed to proceed.

  *

  * @since 0.9.0

  */

 public class RoleAnnotationHandler extends AuthorizingAnnotationHandler {

     /**

      * Default no-argument constructor that ensures this handler looks for

      * {@link org.apache.shiro.authz.annotation.RequiresRoles RequiresRoles} annotations.

      */

     public RoleAnnotationHandler() {

         super(RequiresRoles.class);

     }

     /**

      * Ensures that the calling <code>Subject</code> has the Annotation's specified roles, and if not, throws an

      * <code>AuthorizingException</code> indicating that access is denied.

      *

      * @param a the RequiresRoles annotation to use to check for one or more roles

      * @throws org.apache.shiro.authz.AuthorizationException

      *          if the calling <code>Subject</code> does not have the role(s) necessary to

      *          proceed.

      */

     public void assertAuthorized(Annotation a) throws AuthorizationException {

         if (!(a instanceof RequiresRoles)) return;

         RequiresRoles rrAnnotation = (RequiresRoles) a;

         String[] roles = rrAnnotation.value();

         if (roles.length == 1) {

             getSubject().checkRole(roles[0]);

             return;

         }

         if (Logical.AND.equals(rrAnnotation.logical())) {

             getSubject().checkRoles(Arrays.asList(roles));

             return;

         }

         if (Logical.OR.equals(rrAnnotation.logical())) {

             // Avoid processing exceptions unnecessarily - "delay" throwing the exception by calling hasRole first

             boolean hasAtLeastOneRole = false;

             for (String role : roles) if (getSubject().hasRole(role)) hasAtLeastOneRole = true;

             // Cause the exception if none of the role match, note that the exception message will be a bit misleading

             if (!hasAtLeastOneRole) getSubject().checkRole(roles[0]);

         }

     }

 }