/*

  * Copyright 2007-2008 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.krad.service.impl;

 import com.thoughtworks.xstream.XStream;

 import com.thoughtworks.xstream.converters.MarshallingContext;

 import com.thoughtworks.xstream.converters.UnmarshallingContext;

 import com.thoughtworks.xstream.converters.reflection.ObjectAccessException;

 import com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider;

 import com.thoughtworks.xstream.converters.reflection.ReflectionConverter;

 import com.thoughtworks.xstream.converters.reflection.ReflectionProvider;

 import com.thoughtworks.xstream.io.HierarchicalStreamReader;

 import com.thoughtworks.xstream.io.HierarchicalStreamWriter;

 import com.thoughtworks.xstream.mapper.Mapper;

 import org.apache.ojb.broker.core.proxy.ListProxyDefaultImpl;

 import org.apache.ojb.broker.core.proxy.ProxyHelper;

 import org.kuali.rice.krad.document.Document;

 import org.kuali.rice.krad.service.DocumentSerializerService;

 import org.kuali.rice.krad.service.PersistenceService;

 import org.kuali.rice.krad.service.SerializerService;

 import org.kuali.rice.krad.service.XmlObjectSerializerService;

 import org.kuali.rice.krad.util.documentserializer.AlwaysTruePropertySerializibilityEvaluator;

 import org.kuali.rice.krad.util.documentserializer.PropertySerializabilityEvaluator;

 import org.kuali.rice.krad.util.documentserializer.PropertyType;

 import org.kuali.rice.krad.util.documentserializer.SerializationState;

 import java.lang.reflect.Field;

 import java.util.ArrayList;

 import java.util.Iterator;

 import java.util.List;

 /**

  * Default implementation of the {@link DocumentSerializerService}.  If no <workflowProperties> have been defined in the

  * data dictionary for a document type (i.e. {@link Document#getDocumentPropertySerizabilityEvaluator()} returns an instance of 

  * {@link AlwaysTruePropertySerializibilityEvaluator}), then this service will revert to using the {@link XmlObjectSerializerService}

  * bean, which was the old way of serializing a document for routing.  If workflowProperties are defined, then this implementation

  * will selectively serialize items.

  */

 public abstract class SerializerServiceBase implements SerializerService  {

 //        private static final Log LOG = LogFactory.getLog(SerializerServiceBase.class);

     protected PersistenceService persistenceService;

     protected XmlObjectSerializerService xmlObjectSerializerService;

     protected XStream xstream;

     protected ThreadLocal<SerializationState> serializationStates;

     protected ThreadLocal<PropertySerializabilityEvaluator> evaluators;

     public SerializerServiceBase() {

         serializationStates = new ThreadLocal<SerializationState>();

         evaluators = new ThreadLocal<PropertySerializabilityEvaluator>();

         xstream = new XStream(new ProxyAndStateAwareJavaReflectionProvider());

         xstream.registerConverter(new ProxyConverter(xstream.getMapper(), xstream.getReflectionProvider() ));

         xstream.addDefaultImplementation(ArrayList.class, ListProxyDefaultImpl.class);

         //xstream.registerConverter(new AutoPopulatingListConverter(xstream.getMapper()));

     }

     public class ProxyConverter extends ReflectionConverter {

         public ProxyConverter(Mapper mapper, ReflectionProvider reflectionProvider) {

             super(mapper, reflectionProvider);

         }

         public boolean canConvert(Class clazz) {

             return clazz.getName().contains("CGLIB") || clazz.getName().equals("org.apache.ojb.broker.core.proxy.ListProxyDefaultImpl");

         }

         public void marshal(Object obj, HierarchicalStreamWriter writer, MarshallingContext context) {

             if (obj instanceof ListProxyDefaultImpl) { 

                 List copiedList = new ArrayList(); 

                 List proxiedList = (List) obj; 

                 for (Iterator iter = proxiedList.iterator(); iter.hasNext();) { 

                     copiedList.add(iter.next()); 

                 } 

                 context.convertAnother( copiedList );

             } 

             else { 

                 super.marshal(getPersistenceService().resolveProxy(obj), writer, context);

             }           

         }

         public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) {

             return null;

         }

     }

     public class ProxyAndStateAwareJavaReflectionProvider extends PureJavaReflectionProvider {

         @Override

         public void visitSerializableFields(Object object, Visitor visitor) {

             SerializationState state = serializationStates.get();

             PropertySerializabilityEvaluator evaluator = evaluators.get();

             for (Iterator iterator = fieldDictionary.fieldsFor(object.getClass()); iterator.hasNext();) {

                 Field field = (Field) iterator.next();

                 if (!fieldModifiersSupported(field)) {

                     continue;

                 }

                 if (ignoreField(field)) {

                     continue;

                 }

                 validateFieldAccess(field);

                 initializeField(object, field);

                 Object value = null;

                 try {

                     value = field.get(object);

                 } catch (IllegalArgumentException e) {

                     throw new ObjectAccessException("Could not get field " + field.getClass() + "." + field.getName(), e);

                 } catch (IllegalAccessException e) {

                     throw new ObjectAccessException("Could not get field " + field.getClass() + "." + field.getName(), e);

                 }

                 if (evaluator.isPropertySerializable(state, object, field.getName(), value)) {

                     if (value != null && ProxyHelper.isProxy(value)) {

                         // resolve proxies after we determine that it's serializable

                         value = getPersistenceService().resolveProxy(value);

                     }

                     PropertyType propertyType = evaluator.determinePropertyType(value);

                     state.addSerializedProperty(field.getName(), propertyType);

                     visitor.visit(field.getName(), field.getType(), field.getDeclaringClass(), value);

                     state.removeSerializedProperty();

                 }

             }

         }

         protected boolean ignoreField(Field field) {

             return false;

         }

         protected void initializeField(Object object, Field field) {

         }

     }

     public PersistenceService getPersistenceService() {

         return this.persistenceService;

     }

     public void setPersistenceService(PersistenceService persistenceService) {

         this.persistenceService = persistenceService;

     }

     public XmlObjectSerializerService getXmlObjectSerializerService() {

         return this.xmlObjectSerializerService;

     }

     public void setXmlObjectSerializerService(XmlObjectSerializerService xmlObjectSerializerService) {

         this.xmlObjectSerializerService = xmlObjectSerializerService;

     }

     protected SerializationState createNewDocumentSerializationState(Document document) {

         return new SerializationState();

     }

 //    public class AutoPopulatingListConverter extends CollectionConverter {

 //

 //            public AutoPopulatingListConverter(Mapper mapper){

 //                    super(mapper);

 //            }

 //

 //            public boolean canConvert(Class clazz) {

 //                    return clazz.equals(AutoPopulatingList.class);

 //        }

 //

 //    }

 //    

 }