/*
    * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
    * the spring framework, http://el4j.sf.net
    * Copyright (C) 2005 by ELCA Informatique SA, Av. de la Harpe 22-24,
    * 1000 Lausanne, Switzerland, http://www.elca.ch
    *
    * EL4J is published under the GNU Lesser General Public License (LGPL)
    * Version 2.1. See http://www.gnu.org/licenses/
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU Lesser General Public License for more details.
   *
   * For alternative licensing, please contact info@elca.ch
   */
  
  package ch.elca.el4j.tests.util.metadata.annotations;
  
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Method;
  import java.util.Collection;
  
  import org.aopalliance.intercept.MethodInterceptor;
  import org.aopalliance.intercept.MethodInvocation;
  import org.springframework.aop.support.AopUtils;
  import org.springframework.util.Assert;
  
  import ch.elca.el4j.services.monitoring.notification.CoreNotificationHelper;
  import ch.elca.el4j.util.metadata.GenericMetaDataSource;
  import ch.elca.el4j.util.metadata.MetaDataSourceAware;
  
  /**
   * The interceptor to be invoked if an ExampleAnnotation is set.
   *
   * @svnLink $Revision: 3874 $;$Date: 2009-08-04 14:25:40 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/core/src/test/java/ch/elca/el4j/tests/util/metadata/annotations/ExampleInterceptor.java $
   *
   * @author Martin Zeltner (MZE)
   */
  public class ExampleInterceptor
  	implements MethodInterceptor, MetaDataSourceAware {
  
  	/**
  	 * The annotation source.
  	 */
  	private GenericMetaDataSource m_metaDataSource;
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@SuppressWarnings("unchecked")
  	public Object invoke(MethodInvocation methodInvocation) throws Throwable {
  		Method invokedMethod = methodInvocation.getMethod();
  		Class targetClass = null;
  		if (!AopUtils.isAopProxy(methodInvocation.getThis())) {
  			targetClass = methodInvocation.getThis().getClass();
  		}
  		
  		Collection<Annotation> c = m_metaDataSource.getMetaData(
  			invokedMethod, targetClass);
  
  		Assert.isTrue(c != null && !c.isEmpty());
  		Annotation annotation = c.iterator().next();
  		int factor = -1;
  		if (annotation instanceof ExampleAnnotationOne) {
  			factor = ((ExampleAnnotationOne) annotation).factor();
  		} else if (annotation instanceof ExampleAnnotationTwo) {
  			ExampleAnnotationTwo eat = (ExampleAnnotationTwo) annotation;
  			factor = eat.factor() * ExampleAnnotationTwo.CONSTANT_FACTOR;
  		} else {
  			CoreNotificationHelper.notifyMisconfiguration(
  				"There is no annotated annotation of type "
  				+ "ExampleAnnotation declared at method "
  				+ methodInvocation.getMethod());
  		}
  
  		Object[] param = methodInvocation.getArguments();
  		param[0] = Integer.valueOf(factor);
  
  		// This is an around advice.
  		// Invoke the next interceptor in the chain.
  		// This will normally result in a target object being invoked.
  		return methodInvocation.proceed();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setMetaDataSource(GenericMetaDataSource metaDataSource) {
  		m_metaDataSource = metaDataSource;
  	}
  }