/*

  * Copyright 2007-2010 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.kew.documentlink.dao.impl;

 import java.util.List;

 import javax.persistence.EntityManager;

 import javax.persistence.NoResultException;

 import javax.persistence.PersistenceContext;

 import org.kuali.rice.core.framework.persistence.jpa.OrmUtils;

 import org.kuali.rice.core.framework.persistence.jpa.criteria.Criteria;

 import org.kuali.rice.core.framework.persistence.jpa.criteria.QueryByCriteria;

 import org.kuali.rice.kew.documentlink.DocumentLink;

 import org.kuali.rice.kew.documentlink.dao.DocumentLinkDAO;

 import org.kuali.rice.kns.util.ObjectUtils;

 /**

  * This is a description of what this class does - g1zhang don't forget to fill this in. 

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 public class DocumentLinkDAOJpaImpl implements DocumentLinkDAO {

     @PersistenceContext(unitName = "kew-unit")

     private EntityManager entityManager;

     public EntityManager getEntityManager() {

         return this.entityManager;

     }

     public void setEntityManager(EntityManager entityManager) {

         this.entityManager = entityManager;

     }

         /**

          * double delete all links from orgn doc

          * 

          * @see org.kuali.rice.kew.documentlink.dao.DocumentLinkDAO#deleteDocmentLinksByDocId(java.lang.Long)

          */

         public void deleteDocmentLinksByDocId(String docId) {

                 List<DocumentLink> links = getLinkedDocumentsByDocId(docId);

                 for(DocumentLink link: links){

                         deleteDocumentLink(link);

                 }

         }

         /**

          * double delete a link

          * 

          * @see org.kuali.rice.kew.documentlink.dao.DocumentLinkDAO#deleteDocumentLink(org.kuali.rice.kew.documentlink.DocumentLink)

          */

         public void deleteDocumentLink(DocumentLink link) {

                 deleteSingleLinkFromOrgnDoc(link);

                 deleteSingleLinkFromOrgnDoc(DocumentLinkDaoUtil.reverseLink((DocumentLink)ObjectUtils.deepCopy(link)));

         }

         /**

          * get a link from orgn doc

          * 

          * @see org.kuali.rice.kew.documentlink.dao.DocumentLinkDAO#getLinkedDocument(org.kuali.rice.kew.documentlink.DocumentLink)

          */

         public DocumentLink getLinkedDocument(DocumentLink link) {

                 Criteria crit = new Criteria(DocumentLink.class.getName());

                 crit.eq("orgnDocId", link.getOrgnDocId());

                 crit.eq("destDocId", link.getDestDocId());

                 try {

                         return (DocumentLink) new QueryByCriteria(entityManager, crit).toQuery().getSingleResult();

                 } catch (NoResultException e) {

                         return null;

                 }

         }

         /**

          * get all links from orgn doc

          * 

          * @see org.kuali.rice.kew.documentlink.dao.DocumentLinkDAO#getLinkedDocumentsByDocId(java.lang.Long)

          */

         public List<DocumentLink> getLinkedDocumentsByDocId(String docId) {

                 Criteria crit = new Criteria(DocumentLink.class.getName());

                 crit.eq("orgnDocId", docId);

                 return (List<DocumentLink>) new QueryByCriteria(entityManager, crit).toQuery().getResultList();

         }

         /**

          * add double link

          * 

          * @see org.kuali.rice.kew.documentlink.dao.DocumentLinkDAO#saveDocumentLink(org.kuali.rice.kew.documentlink.DocumentLink)

          */

         public void saveDocumentLink(DocumentLink link) {

                 if(getLinkedDocument(link) == null) {

                         if (link.getDocLinkId() == null) {

                                 entityManager.persist(link);

                         } else {

                                 OrmUtils.merge(entityManager, link);

                         }

                 }

 //                //if we want a 2-way linked pair

                 DocumentLink rLink = DocumentLinkDaoUtil.reverseLink((DocumentLink)ObjectUtils.deepCopy(link));

                 if(getLinkedDocument(rLink) == null) {

                         if (link.getDocLinkId() == null) {

                                 entityManager.persist(rLink);

                         } else {

                                 OrmUtils.merge(entityManager, rLink);

                         }

                 }

         }

         private void deleteSingleLinkFromOrgnDoc(DocumentLink link){

                 DocumentLink cur = getLinkedDocument(link);

                 entityManager.remove(cur) ;

         }

 }