/* 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
    *
    *     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.cateproject.view.authz;
  
  import org.springframework.security.taglibs.authz.AccessControlListTag;
  import org.springframework.security.taglibs.authz.AuthenticationTag;
  import org.springframework.security.taglibs.authz.AuthorizeTag;
  import org.springframework.security.taglibs.velocity.Authz;
  
  import org.springframework.context.ApplicationContext;
  
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.PageContext;
  import javax.servlet.jsp.tagext.Tag;
  
  
  /**
   * I decided to wrap several JSP tag in one class, so I have to using inner class to wrap these JSP tag.  To using
   * this class, you need to inject Spring Context via SetAppCtx() method. AclTag need Spring Context to get AclManger
   * bean.
   */
  public class AuthzImpl implements Authz {
      //~ Static fields/initializers =====================================================================================
  
      static final int ALL_GRANTED = 1;
      static final int ANY_GRANTED = 2;
      static final int NONE_GRANTED = 3;
  
      //~ Instance fields ================================================================================================
  
      private ApplicationContext appCtx;
  
      //~ Methods ========================================================================================================
  
      public boolean allGranted(String roles) {
          return ifGranted(roles, ALL_GRANTED);
      }
  
      public boolean anyGranted(String roles) {
          return ifGranted(roles, ANY_GRANTED);
      }
  
      public ApplicationContext getAppCtx() {
          return appCtx;
      }
  
      /**
       * implementation of AuthenticationTag
       *
       * @return DOCUMENT ME!
       *
       * @throws IllegalArgumentException DOCUMENT ME!
       */
      public String getPrincipal() {
          MyAuthenticationTag authenticationTag = new MyAuthenticationTag();
  
          authenticationTag.setProperty("name");
  
          try {
              authenticationTag.doStartTag();
              authenticationTag.doEndTag();
          } catch (JspException je) {
              je.printStackTrace();
              return null;
          }
  
          return authenticationTag.getLastMessage();
      }
  
      /**
       * implementation of AclTag
       *
       * @param domainObject DOCUMENT ME!
       * @param permissions DOCUMENT ME!
       *
       * @return DOCUMENT ME!
       *
       * @throws IllegalArgumentException DOCUMENT ME!
       */
      public boolean hasPermission(Object domainObject, String permissions) {
          MyAclTag aclTag = new MyAclTag();
          aclTag.setPageContext(null);
          aclTag.setContext(getAppCtx());
          aclTag.setDomainObject(domainObject);
          aclTag.setHasPermission(permissions);
  
          int result = -1;
 
         try {
             result = aclTag.doStartTag();
         } catch (JspException je) {
             throw new IllegalArgumentException(je.getMessage());
         }
 
         if (Tag.EVAL_BODY_INCLUDE == result) {
             return true;
         } else {
             return false;
         }
     }
 
     /**
      * implementation of AuthorizeTag
      *
      * @param roles DOCUMENT ME!
      * @param grantType DOCUMENT ME!
      *
      * @return DOCUMENT ME!
      *
      * @throws IllegalArgumentException DOCUMENT ME!
      */
     private boolean ifGranted(String roles, int grantType) {
         AuthorizeTag authorizeTag = new AuthorizeTag();
 
         int result = -1;
 
         try {
             switch (grantType) {
             case ALL_GRANTED:
                 authorizeTag.setIfAllGranted(roles);
 
                 break;
 
             case ANY_GRANTED:
                 authorizeTag.setIfAnyGranted(roles);
 
                 break;
 
             case NONE_GRANTED:
                 authorizeTag.setIfNotGranted(roles);
 
                 break;
 
             default:
                 throw new IllegalArgumentException("invalid granted type : " + grantType + " role=" + roles);
             }
 
             result = authorizeTag.doStartTag();
         } catch (JspException je) {
             throw new IllegalArgumentException(je.getMessage());
         }
 
         if (Tag.EVAL_BODY_INCLUDE == result) {
             return true;
         } else {
             return false;
         }
     }
 
     public boolean noneGranted(String roles) {
         return ifGranted(roles, NONE_GRANTED);
     }
 
     /**
      * test case can use this class to mock application context with aclManager bean in it.
      *
      * @param appCtx DOCUMENT ME!
      */
     public void setAppCtx(ApplicationContext appCtx) {
         this.appCtx = appCtx;
     }
 
     //~ Inner Classes ==================================================================================================
 
     /**
      * AclTag need to access the application context via the <code> WebApplicationContextUtils</code> and
      * locate an {@link AclManager}. WebApplicationContextUtils get application context via ServletContext. I decided
      * to let the Authz provide the Spring application context.
      */
     private class MyAclTag extends AccessControlListTag {
         private static final long serialVersionUID = 6752340622125924108L;
         ApplicationContext context;
 
         protected ApplicationContext getContext(PageContext pageContext) {
             return context;
         }
 
         protected void setContext(ApplicationContext context) {
             this.context = context;
         }
     }
 
     /**
      * it must output somthing to JSP page, so have to override the writeMessage method to avoid JSP related
      * operation. Get Idea from Acegi Test class.
      */
     private class MyAuthenticationTag extends AuthenticationTag {
         private static final long serialVersionUID = -1094246833893599161L;
         String lastMessage = null;
 
         public String getLastMessage() {
             return lastMessage;
         }
 
         protected void writeMessage(String msg) throws JspException {
             lastMessage = msg;
         }
     }
 }