/* 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.acegisecurity.intercept.method;

 import org.acegisecurity.ConfigAttributeDefinition;

 import org.aopalliance.intercept.MethodInvocation;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.aspectj.lang.JoinPoint;

 import org.aspectj.lang.reflect.CodeSignature;

 import org.springframework.util.Assert;

 import java.lang.reflect.Method;

 /**

  * Abstract implementation of <Code>MethodDefinitionSource</code>.

  *

  * @author Ben Alex

  * @version $Id: AbstractMethodDefinitionSource.java 1496 2006-05-23 13:38:33Z benalex $

  */

 public abstract class AbstractMethodDefinitionSource implements MethodDefinitionSource {

     //~ Static fields/initializers =====================================================================================

     private static final Log logger = LogFactory.getLog(AbstractMethodDefinitionSource.class);

     //~ Methods ========================================================================================================

     public ConfigAttributeDefinition getAttributes(Object object)

         throws IllegalArgumentException {

         Assert.notNull(object, "Object cannot be null");

         if (object instanceof MethodInvocation) {

             return this.lookupAttributes(((MethodInvocation) object).getMethod());

         }

         if (object instanceof JoinPoint) {

             JoinPoint jp = (JoinPoint) object;

             Class targetClazz = jp.getTarget().getClass();

             String targetMethodName = jp.getStaticPart().getSignature().getName();

             Class[] types = ((CodeSignature) jp.getStaticPart().getSignature()).getParameterTypes();

             if (logger.isDebugEnabled()) {

                 logger.debug("Target Class: " + targetClazz);

                 logger.debug("Target Method Name: " + targetMethodName);

                 for (int i = 0; i < types.length; i++) {

                     if (logger.isDebugEnabled()) {

                         logger.debug("Target Method Arg #" + i + ": " + types[i]);

                     }

                 }

             }

             try {

                 return this.lookupAttributes(targetClazz.getMethod(targetMethodName, types));

             } catch (NoSuchMethodException nsme) {

                 throw new IllegalArgumentException("Could not obtain target method from JoinPoint: " + jp);

             }

         }

         throw new IllegalArgumentException("Object must be a MethodInvocation or JoinPoint");

     }

     /**

      * Performs the actual lookup of the relevant <code>ConfigAttributeDefinition</code> for the specified

      * <code>Method</code> which is subject of the method invocation.<P>Provided so subclasses need only to

      * provide one basic method to properly interface with the <code>MethodDefinitionSource</code>.</p>

      *  <p>Returns <code>null</code> if there are no matching attributes for the method.</p>

      *

      * @param method the method being invoked for which configuration attributes should be looked up

      *

      * @return the <code>ConfigAttributeDefinition</code> that applies to the specified <code>Method</code>

      */

     protected abstract ConfigAttributeDefinition lookupAttributes(Method method);

     public boolean supports(Class clazz) {

         return (MethodInvocation.class.isAssignableFrom(clazz) || JoinPoint.class.isAssignableFrom(clazz));

     }

 }