package org.trails.descriptor.annotation;

 import java.beans.Introspector;

 import java.beans.PropertyDescriptor;

 import java.lang.annotation.Annotation;

 import java.lang.reflect.Field;

 import java.lang.reflect.Method;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.Iterator;

 import ognl.Ognl;

 import org.trails.descriptor.DescriptorDecorator;

 import org.trails.descriptor.IClassDescriptor;

 import org.trails.descriptor.IDescriptor;

 import org.trails.descriptor.IPropertyDescriptor;

 import org.trails.descriptor.EmbeddedDescriptor;

 /**

  * This class uses the annotations on a given class or property to modify its

  * descriptor

  *

  * @author Chris Nelson

  */

 public class AnnotationDecorator implements DescriptorDecorator

 {

         public IClassDescriptor decorate(IClassDescriptor descriptor)

         {

                 Annotation[] classAnnotations = descriptor.getType().getAnnotations();

                 IClassDescriptor decoratedDescriptor = (IClassDescriptor) decorateFromAnnotations(descriptor, classAnnotations);

                 ArrayList decoratedPropertyDescriptors = new ArrayList();

                 for (Iterator iter = descriptor.getPropertyDescriptors().iterator(); iter.hasNext();)

                 {

                         IPropertyDescriptor propertyDescriptor = (IPropertyDescriptor) iter.next();

                         IPropertyDescriptor clonedDescriptor = decoratePropertyDescriptor(propertyDescriptor);

                         // recursively decorate components

                         if (clonedDescriptor.isEmbedded())

                         {

                                 clonedDescriptor = (EmbeddedDescriptor) decorate((EmbeddedDescriptor) clonedDescriptor);

                         }

                         decoratedPropertyDescriptors.add(clonedDescriptor);

                 }

                 decoratedDescriptor.setPropertyDescriptors(decoratedPropertyDescriptors);

                 sortDescriptors(decoratedDescriptor);

                 return decoratedDescriptor;

         }

         protected IPropertyDescriptor decoratePropertyDescriptor(IPropertyDescriptor propertyDescriptor)

         {

                 IPropertyDescriptor clonedDescriptor = (IPropertyDescriptor) propertyDescriptor.clone();

                 try

                 {

                         Field propertyField = clonedDescriptor.getBeanType().getDeclaredField(

                                 propertyDescriptor.getName());

                         clonedDescriptor = (IPropertyDescriptor) decorateFromAnnotations(clonedDescriptor, propertyField.getAnnotations());

                 } catch (Exception ex)

                 {

                         // don't care

                 }

                 try

                 {

                         PropertyDescriptor beanPropDescriptor = (PropertyDescriptor) Ognl.getValue("propertyDescriptors.{? name == '" + propertyDescriptor.getName() + "'}[0]",

                                 Introspector.getBeanInfo(clonedDescriptor.getBeanType()));

                         Method readMethod = beanPropDescriptor.getReadMethod();

                         clonedDescriptor = (IPropertyDescriptor) decorateFromAnnotations(clonedDescriptor, readMethod.getAnnotations());

                 }

                 catch (Exception ex)

                 {

                         //System.out.println(propertyDescriptor.getName());

                         //ex.printStackTrace();

                         // don't care

                 }

                 return clonedDescriptor;

         }

         /**

          * Rearrange the property descriptors by their index

          *

          * @param descriptor

          */

         private void sortDescriptors(IClassDescriptor descriptor)

         {

                 ArrayList sortedDescriptors = new ArrayList();

                 sortedDescriptors.addAll(descriptor.getPropertyDescriptors());

                 for (Iterator iter = descriptor.getPropertyDescriptors().iterator(); iter.hasNext();)

                 {

                         IPropertyDescriptor propertyDescriptor = (IPropertyDescriptor) iter.next();

                         if (propertyDescriptor.getIndex() != IPropertyDescriptor.UNDEFINED_INDEX)

                         {

                                 Collections.swap(sortedDescriptors,

                                         propertyDescriptor.getIndex(),

                                         sortedDescriptors.indexOf(propertyDescriptor));

                         }

                 }

                 descriptor.setPropertyDescriptors(sortedDescriptors);

         }

         private IDescriptor decorateFromAnnotations(IDescriptor descriptor, Annotation[] annotations)

         {

                 IDescriptor clonedDescriptor = (IDescriptor) descriptor.clone();

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

                 {

                         Annotation annotation = annotations[i];

                         // If the annotation type itself has a DescriptorAnnotation, it's one of ours

                         DescriptorAnnotation handlerAnnotation = annotation.annotationType().getAnnotation(DescriptorAnnotation.class);

                         if (handlerAnnotation != null)

                         {

                                 try

                                 {

                                         DescriptorAnnotationHandler handler = handlerAnnotation.value().newInstance();

                                         clonedDescriptor = handler.decorateFromAnnotation(annotation, clonedDescriptor);

                                 }

                                 catch (Exception ex)

                                 {

                                         //ex.printStackTrace();

                                 }

                         }

                 }

                 return clonedDescriptor;

         }

 }