/*

  * 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.kns.dao.impl;

 import java.lang.reflect.Field;

 import java.util.ArrayList;

 import java.util.HashMap;

 import java.util.Map;

 import javax.persistence.EntityManager;

 import javax.persistence.PersistenceContext;

 import org.kuali.rice.core.jpa.metadata.CollectionDescriptor;

 import org.kuali.rice.core.jpa.metadata.EntityDescriptor;

 import org.kuali.rice.core.jpa.metadata.MetadataManager;

 import org.kuali.rice.core.jpa.metadata.ObjectDescriptor;

 import org.kuali.rice.kns.bo.PersistableBusinessObject;

 import org.kuali.rice.kns.dao.PersistenceDao;

 import org.kuali.rice.kns.service.KNSServiceLocator;

 public class PersistenceDaoJpa implements PersistenceDao {

         /**

          * @see org.kuali.rice.kns.dao.PersistenceDao#clearCache()

          */

         public void clearCache() {}

         /**

          * @see org.kuali.rice.kns.dao.PersistenceDao#resolveProxy(java.lang.Object)

          */

         public Object resolveProxy(Object o) {

                 return o;

         }

         /**

          * @see org.kuali.rice.kns.dao.PersistenceDao#retrieveAllReferences(java.lang.Object)

          */

         public void retrieveAllReferences(Object o) {

                 EntityDescriptor ed = MetadataManager.getEntityDescriptor(o.getClass());

                 for (ObjectDescriptor od : ed.getObjectRelationships()) {

                         retrieveReference(o, od.getAttributeName());

                 }

                 for (CollectionDescriptor cd : ed.getCollectionRelationships()) {

                         retrieveReference(o, cd.getAttributeName());

                 }

         }

         /**

          * @see org.kuali.rice.kns.dao.PersistenceDao#retrieveReference(java.lang.Object, java.lang.String)

          */

         public void retrieveReference(Object o, String referenceName) {

                 try {

                         Field field = getField(o.getClass(), referenceName);

                         field.setAccessible(true);

                         String fk = null;

                         EntityDescriptor ed = MetadataManager.getEntityDescriptor(o.getClass());

                         CollectionDescriptor cd = ed.getCollectionDescriptorByName(referenceName);

                         if (cd == null) {

                                 ObjectDescriptor od = ed.getObjectDescriptorByName(referenceName);

                                 fk = od.getForeignKeyFields().get(0);

                         } else {

                                 fk = cd.getForeignKeyFields().get(0);

                         }

                         Field field2 = null;

                         try {

                                 field2 = getField(o.getClass(), fk);

                         } catch (Exception e) {

                                 String pk = ed.getPrimaryKeys().iterator().next().getName();                                

                                 field2 = getField(o.getClass(), pk);

                         }

                         field2.setAccessible(true);

                         Object fkFieldValue = field2.get(o);

                         if ("java.util.List".equals(field.getType().getCanonicalName())) {        

                                 Field field3 = getField(o.getClass(), ed.getPrimaryKeys().iterator().next().getName());

                                 field3.setAccessible(true);

                                 if (field3.get(o) == null) {

                                         field.set(o, new ArrayList());

                                 } else {

                                         Map pk = new HashMap();

                                         pk.put(cd.getForeignKeyFields().get(0), field3.get(o));

                                         field.set(o, KNSServiceLocator.getBusinessObjectService().findMatching(cd.getTargetEntity(), pk));

                                 }

                         } else {

                                 PersistableBusinessObject pbo = (PersistableBusinessObject) Class.forName(field.getType().getCanonicalName()).newInstance();

                     Map<String, Object> keys = MetadataManager.getPersistableBusinessObjectPrimaryKeyValuePairs(pbo);

                                 Field field3 = getField(pbo.getClass(), keys.keySet().iterator().next());

                                 field3.setAccessible(true);

                                 field3.set(pbo, fkFieldValue);

                                 field.set(o, KNSServiceLocator.getBusinessObjectService().retrieve(pbo));

                         }

                 } catch (Exception e) {

                         e.printStackTrace();

                 }                

         }

         private Field getField(Class clazz, String name) throws NoSuchFieldException {

                 if (clazz.equals(Object.class)) {

                         throw new NoSuchFieldException(name);

                 }

                 Field field = null;

                 try {

                         field = clazz.getDeclaredField(name);

                 } catch (Exception e) {}

                 if (field == null) {

                         field = getField(clazz.getSuperclass(), name);

                 }

                 return field;

         }

 }