/*

  * 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.lookup;

 import java.sql.Timestamp;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import org.apache.commons.codec.binary.Base64;

 import org.kuali.rice.core.api.CoreApiServiceLocator;

 import org.kuali.rice.kns.web.ui.ResultRow;

 import org.kuali.rice.krad.bo.BusinessObject;

 import org.kuali.rice.krad.bo.LookupResults;

 import org.kuali.rice.krad.bo.MultipleValueLookupMetadata;

 import org.kuali.rice.krad.bo.SelectedObjectIds;

 import org.kuali.rice.krad.dao.PersistedLookupMetadataDao;

 import org.kuali.rice.krad.exception.AuthorizationException;

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

 import org.kuali.rice.krad.util.KRADConstants;

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

 public class LookupResultsServiceImpl implements LookupResultsService {

     private BusinessObjectService businessObjectService;

     private PersistedLookupMetadataDao persistedLookupMetadataDao;

     private LookupResultsSupportStrategyService persistableBusinessObjectSupportStrategy;

     private LookupResultsSupportStrategyService dataDictionarySupportStrategy;

     /**

      * @see org.kuali.rice.krad.lookup.LookupResultsService#persistResultsTable(java.lang.String, java.util.List, java.lang.String)

      */

     public void persistResultsTable(String lookupResultsSequenceNumber, List<ResultRow> resultTable, String personId) throws Exception {

         String resultTableString = new String(Base64.encodeBase64(ObjectUtils.toByteArray(resultTable)));

         Timestamp now = CoreApiServiceLocator.getDateTimeService().getCurrentTimestamp();

         LookupResults lookupResults = retrieveLookupResults(lookupResultsSequenceNumber);

         if (lookupResults == null) {

             lookupResults = new LookupResults();

             lookupResults.setLookupResultsSequenceNumber(lookupResultsSequenceNumber);

         }

         lookupResults.setLookupResultsSequenceNumber(lookupResultsSequenceNumber);

         lookupResults.setLookupPersonId(personId);

         lookupResults.setSerializedLookupResults(resultTableString);

         lookupResults.setLookupDate(now);

         businessObjectService.save(lookupResults);

     }

     /**

      * @see org.kuali.rice.krad.lookup.LookupResultsService#persistSelectedObjectIds(java.lang.String, java.util.Set, java.lang.String)

      */

     public void persistSelectedObjectIds(String lookupResultsSequenceNumber, Set<String> selectedObjectIds, String personId) throws Exception {

         SelectedObjectIds selectedObjectIdsBO = retrieveSelectedObjectIds(lookupResultsSequenceNumber);

         if (selectedObjectIdsBO == null) {

             selectedObjectIdsBO = new SelectedObjectIds();

             selectedObjectIdsBO.setLookupResultsSequenceNumber(lookupResultsSequenceNumber);

         }

         selectedObjectIdsBO.setLookupResultsSequenceNumber(lookupResultsSequenceNumber);

         selectedObjectIdsBO.setLookupPersonId(personId);

         selectedObjectIdsBO.setSelectedObjectIds(

                 LookupUtils.convertSetOfObjectIdsToString(selectedObjectIds));

         selectedObjectIdsBO.setLookupDate(CoreApiServiceLocator.getDateTimeService().getCurrentTimestamp());

         businessObjectService.save(selectedObjectIdsBO);

     }

     /**

      * Retrieves the LookupResults BO with the given sequence number.  Does not check authentication.

      * @param lookupResultsSequenceNumber

      * @return

      * @throws Exception

      */

     protected LookupResults retrieveLookupResults(String lookupResultsSequenceNumber) throws Exception {

         Map<String, String> queryCriteria = new HashMap<String, String>();

         queryCriteria.put(KRADConstants.LOOKUP_RESULTS_SEQUENCE_NUMBER, lookupResultsSequenceNumber);

         LookupResults lookupResults = (LookupResults) businessObjectService.findByPrimaryKey(LookupResults.class, queryCriteria);

         return lookupResults;

     }

     /**

      * Retrieves the SelectedObjectIds BO with the given sequence number.  Does not check authentication.

      * @param lookupResultsSequenceNumber

      * @return

      * @throws Exception

      */

     protected SelectedObjectIds retrieveSelectedObjectIds(String lookupResultsSequenceNumber) throws Exception {

         Map<String, String> queryCriteria = new HashMap<String, String>();

         queryCriteria.put(KRADConstants.LOOKUP_RESULTS_SEQUENCE_NUMBER, lookupResultsSequenceNumber);

         SelectedObjectIds selectedObjectIds = (SelectedObjectIds) businessObjectService.findByPrimaryKey(SelectedObjectIds.class, queryCriteria);

         return selectedObjectIds;

     }

     /**

      * @see org.kuali.rice.krad.lookup.LookupResultsService#isAuthorizedToAccessLookupResults(java.lang.String, java.lang.String)

      */

     public boolean isAuthorizedToAccessLookupResults(String lookupResultsSequenceNumber, String personId) {

         try {

             LookupResults lookupResults = retrieveLookupResults(lookupResultsSequenceNumber);

             return isAuthorizedToAccessLookupResults(lookupResults, personId);

         }

         catch (Exception e) {

             return false;

         }

     }

     /**

      * Returns whether the user ID parameter is allowed to view the results.

      * 

      * @param lookupResults

      * @param personId

      * @return

      */

     protected boolean isAuthorizedToAccessLookupResults(LookupResults lookupResults, String personId) {

         return isAuthorizedToAccessMultipleValueLookupMetadata(lookupResults, personId);

     }

     /**

      * @see org.kuali.rice.krad.lookup.LookupResultsService#isAuthorizedToAccessSelectedObjectIds(java.lang.String, java.lang.String)

      */

     public boolean isAuthorizedToAccessSelectedObjectIds(String lookupResultsSequenceNumber, String personId) {

         try {

             SelectedObjectIds selectedObjectIds = retrieveSelectedObjectIds(lookupResultsSequenceNumber);

             return isAuthorizedToAccessSelectedObjectIds(selectedObjectIds, personId);

         }

         catch (Exception e) {

             return false;

         }

     }

     /**

      * Returns whether the user ID parameter is allowed to view the selected object IDs

      * 

      * @param selectedObjectIds

      * @param personId

      * @return

      */

     protected boolean isAuthorizedToAccessSelectedObjectIds(SelectedObjectIds selectedObjectIds, String personId) {

         return isAuthorizedToAccessMultipleValueLookupMetadata(selectedObjectIds, personId);

     }

     /**

      * @see org.kuali.rice.krad.lookup.LookupResultsService#retrieveResultsTable(java.lang.String, java.lang.String)

      */

     public List<ResultRow> retrieveResultsTable(String lookupResultsSequenceNumber, String personId) throws Exception {

         LookupResults lookupResults = retrieveLookupResults(lookupResultsSequenceNumber);

         if (!isAuthorizedToAccessLookupResults(lookupResults, personId)) {

             // TODO: use the other identifier

             throw new AuthorizationException(personId, "retrieve lookup results", "lookup sequence number " + lookupResultsSequenceNumber);

         }

         List<ResultRow> resultTable = (List<ResultRow>) ObjectUtils.fromByteArray(Base64.decodeBase64(lookupResults.getSerializedLookupResults().getBytes()));

         return resultTable;

     }

     /**

      * Figures out which support strategy to defer to and uses that service to retrieve the results; if the bo class doesn't qualify with any support strategy, an exception is thrown.  A nasty one, too.

      * 

      * @see org.kuali.rice.krad.lookup.LookupResultsService#retrieveSelectedResultBOs(java.lang.String, java.lang.Class, java.lang.String)

      */

     public <T extends BusinessObject> Collection<T> retrieveSelectedResultBOs(String lookupResultsSequenceNumber, Class<T> boClass, String personId) throws Exception {

             final LookupResultsSupportStrategyService supportService = getQualifingSupportStrategy(boClass);

             if (supportService == null) {

                     throw new RuntimeException("BusinessObject class "+boClass.getName()+" cannot be used within a multiple value lookup; it either needs to be a PersistableBusinessObject or have both its primary keys and a lookupable defined in its data dictionary entry");

             }

             SelectedObjectIds selectedObjectIds = retrieveSelectedObjectIds(lookupResultsSequenceNumber);

         if (!isAuthorizedToAccessSelectedObjectIds(selectedObjectIds, personId)) {

             // TODO: use the other identifier

             throw new AuthorizationException(personId, "retrieve lookup results", "lookup sequence number " + lookupResultsSequenceNumber);

         }

         Set<String> setOfSelectedObjIds = LookupUtils

                 .convertStringOfObjectIdsToSet(selectedObjectIds.getSelectedObjectIds());

         if (setOfSelectedObjIds.isEmpty()) {

             // OJB throws exception if querying on empty set

             return new ArrayList<T>();

         }

             return supportService.retrieveSelectedResultBOs(boClass, setOfSelectedObjIds);

     }

     /**

      * Given the business object class, determines the best qualifying LookupResultsSupportStrategyService to use

      * 

      * @param boClass a business object class

      * @return an LookupResultsSupportStrategyService implementation, or null if no qualifying strategies could be found

      */

     protected LookupResultsSupportStrategyService getQualifingSupportStrategy(Class boClass) {

             if (getPersistableBusinessObjectSupportStrategy().qualifiesForStrategy(boClass)) {

                     return getPersistableBusinessObjectSupportStrategy();

             } else if (getDataDictionarySupportStrategy().qualifiesForStrategy(boClass)) {

                     return getDataDictionarySupportStrategy();

             }

             return null;

     }

     /**

      * @see org.kuali.rice.krad.lookup.LookupResultsService#clearPersistedLookupResults(java.lang.String)

      */

     public void clearPersistedLookupResults(String lookupResultsSequenceNumber) throws Exception {

         LookupResults lookupResults = retrieveLookupResults(lookupResultsSequenceNumber);

         if (lookupResults != null) {

             businessObjectService.delete(lookupResults);

         }

     }

     /**

      * @see org.kuali.rice.krad.lookup.LookupResultsService#clearPersistedSelectedObjectIds(java.lang.String)

      */

     public void clearPersistedSelectedObjectIds(String lookupResultsSequenceNumber) throws Exception {

         SelectedObjectIds selectedObjectIds = retrieveSelectedObjectIds(lookupResultsSequenceNumber);

         if (selectedObjectIds != null) {

             businessObjectService.delete(selectedObjectIds);

         }

     }

     /**

          * Figures out which LookupResultsServiceSupportStrategy to defer to, and uses that to get the lookup id

          * @see org.kuali.rice.krad.lookup.LookupResultsService#getLookupId(org.kuali.rice.krad.bo.BusinessObject)

          */

         public String getLookupId(BusinessObject businessObject) {

                 final LookupResultsSupportStrategyService supportService = getQualifingSupportStrategy(businessObject.getClass());

                 if (supportService == null) {

                         return null; // this may happen quite often, so let's just return null - no exception here

                 }

                 return supportService.getLookupIdForBusinessObject(businessObject);

         }

         public BusinessObjectService getBusinessObjectService() {

         return businessObjectService;

     }

     public void setBusinessObjectService(BusinessObjectService businessObjectService) {

         this.businessObjectService = businessObjectService;

     }

     /**

      * Determines whether the passed in user ID is allowed to view the lookup metadata (object IDs or results table)

      * @param mvlm

      * @param personId

      * @return

      */

     protected boolean isAuthorizedToAccessMultipleValueLookupMetadata(MultipleValueLookupMetadata mvlm, String personId) {

         return personId.equals(mvlm.getLookupPersonId());

     }

     public void deleteOldLookupResults(Timestamp expirationDate) {

         persistedLookupMetadataDao.deleteOldLookupResults(expirationDate);

     }

     public void deleteOldSelectedObjectIds(Timestamp expirationDate) {

         persistedLookupMetadataDao.deleteOldSelectedObjectIds(expirationDate);

     }

     public PersistedLookupMetadataDao getPersistedLookupMetadataDao() {

         return persistedLookupMetadataDao;

     }

     public void setPersistedLookupMetadataDao(PersistedLookupMetadataDao persistedLookupMetadataDao) {

         this.persistedLookupMetadataDao = persistedLookupMetadataDao;

     }

         /**

          * @return the persistableBusinessObjectSupportStrategy

          */

         public LookupResultsSupportStrategyService getPersistableBusinessObjectSupportStrategy() {

                 return this.persistableBusinessObjectSupportStrategy;

         }

         /**

          * @return the dataDictionarySupportStrategy

          */

         public LookupResultsSupportStrategyService getDataDictionarySupportStrategy() {

                 return this.dataDictionarySupportStrategy;

         }

         /**

          * @param persistableBusinessObjectSupportStrategy the persistableBusinessObjectSupportStrategy to set

          */

         public void setPersistableBusinessObjectSupportStrategy(

                         LookupResultsSupportStrategyService persistableBusinessObjectSupportStrategy) {

                 this.persistableBusinessObjectSupportStrategy = persistableBusinessObjectSupportStrategy;

         }

         /**

          * @param dataDictionarySupportStrategy the dataDictionarySupportStrategy to set

          */

         public void setDataDictionarySupportStrategy(

                         LookupResultsSupportStrategyService dataDictionarySupportStrategy) {

                 this.dataDictionarySupportStrategy = dataDictionarySupportStrategy;

         }

 }