package org.kuali.student.lum.course.service.impl;

 import java.util.ArrayList;

 import java.util.Date;

 import java.util.List;

 import org.apache.log4j.Logger;

 import org.kuali.student.common.assembly.BaseDTOAssemblyNode;

 import org.kuali.student.common.assembly.BusinessServiceMethodInvoker;

 import org.kuali.student.common.assembly.BaseDTOAssemblyNode.NodeOperation;

 import org.kuali.student.common.assembly.data.AssemblyException;

 import org.kuali.student.common.dictionary.dto.ObjectStructureDefinition;

 import org.kuali.student.common.dictionary.service.DictionaryService;

 import org.kuali.student.common.dto.StatusInfo;

 import org.kuali.student.common.exceptions.AlreadyExistsException;

 import org.kuali.student.common.exceptions.CircularReferenceException;

 import org.kuali.student.common.exceptions.CircularRelationshipException;

 import org.kuali.student.common.exceptions.DataValidationErrorException;

 import org.kuali.student.common.exceptions.DependentObjectsExistException;

 import org.kuali.student.common.exceptions.DoesNotExistException;

 import org.kuali.student.common.exceptions.IllegalVersionSequencingException;

 import org.kuali.student.common.exceptions.InvalidParameterException;

 import org.kuali.student.common.exceptions.MissingParameterException;

 import org.kuali.student.common.exceptions.OperationFailedException;

 import org.kuali.student.common.exceptions.PermissionDeniedException;

 import org.kuali.student.common.exceptions.UnsupportedActionException;

 import org.kuali.student.common.exceptions.VersionMismatchException;

 import org.kuali.student.common.validation.dto.ValidationResultInfo;

 import org.kuali.student.common.validator.Validator;

 import org.kuali.student.common.validator.ValidatorFactory;

 import org.kuali.student.common.validator.ValidatorUtils;

 import org.kuali.student.common.versionmanagement.dto.VersionDisplayInfo;

 import org.kuali.student.core.statement.dto.RefStatementRelationInfo;

 import org.kuali.student.core.statement.dto.ReqCompFieldInfo;

 import org.kuali.student.core.statement.dto.ReqComponentInfo;

 import org.kuali.student.core.statement.dto.StatementTreeViewInfo;

 import org.kuali.student.core.statement.service.StatementService;

 import org.kuali.student.lum.course.dto.ActivityInfo;

 import org.kuali.student.lum.course.dto.CourseInfo;

 import org.kuali.student.lum.course.dto.CourseJointInfo;

 import org.kuali.student.lum.course.dto.FormatInfo;

 import org.kuali.student.lum.course.dto.LoDisplayInfo;

 import org.kuali.student.lum.course.service.CourseService;

 import org.kuali.student.lum.course.service.CourseServiceConstants;

 import org.kuali.student.lum.course.service.assembler.CourseAssembler;

 import org.kuali.student.lum.course.service.assembler.CourseAssemblerConstants;

 import org.kuali.student.lum.lu.dto.CluInfo;

 import org.kuali.student.lum.lu.dto.CluSetInfo;

 import org.kuali.student.lum.lu.service.LuService;

 import org.kuali.student.lum.lu.service.LuServiceConstants;

 import org.kuali.student.lum.statement.typekey.ReqComponentFieldTypes;

 import org.springframework.transaction.annotation.Transactional;

 /**

  * CourseServiceImpl implements CourseService Interface by mapping DTOs in CourseInfo to underlying entity DTOs like CluInfo

  * and CluCluRelationInfo.

  *

  * For Credits, there are three credit types that are set with a combination of type and dynamic attributes

  * To set a variable(range) credit option,

  * set the ResultComponentInfo type to CourseAssemblerConstants.COURSE_RESULT_COMP_TYPE_CREDIT_VARIABLE

  * and add the dynamic attributes CourseAssemblerConstants.COURSE_RESULT_COMP_ATTR_MIN_CREDIT_VALUE and 

  * CourseAssemblerConstants.COURSE_RESULT_COMP_ATTR_MAX_CREDIT_VALUE with respective credit min and max values.

  * 

  * To set a fixed credit option,

  * set the ResultComponentInfo type to CourseAssemblerConstants.COURSE_RESULT_COMP_TYPE_CREDIT_FIXED

  * and add the dynamic attribute CourseAssemblerConstants.COURSE_RESULT_COMP_ATTR_FIXED_CREDIT_VALUE

  * with the fixed credit value

  * 

  * To Set multiple credit options, 

  * set the ResultComponentInfo type to CourseAssemblerConstants.COURSE_RESULT_COMP_TYPE_CREDIT_MULTIPLE

  * and add each credit as a numeric ResultValue on the ResultComponentInfo for each credit you desire

  *

  * @author Kuali Student Team

  */

 @Transactional(readOnly=true,noRollbackFor={DoesNotExistException.class},rollbackFor={Throwable.class})

 public class CourseServiceImpl implements CourseService {

     final static Logger LOG = Logger.getLogger(CourseServiceImpl.class);

     private LuService luService;

     private CourseAssembler courseAssembler;

     private BusinessServiceMethodInvoker courseServiceMethodInvoker;

     private DictionaryService dictionaryServiceDelegate;

     private ValidatorFactory validatorFactory;

     private StatementService statementService;

     @Override

     @Transactional(readOnly=false)

         public CourseInfo createCourse(CourseInfo courseInfo) throws AlreadyExistsException, DataValidationErrorException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException, VersionMismatchException, DoesNotExistException, CircularRelationshipException, DependentObjectsExistException, UnsupportedActionException {

         checkForMissingParameter(courseInfo, "CourseInfo");

         // Validate

         List<ValidationResultInfo> validationResults = validateCourse("OBJECT", courseInfo);

         if (ValidatorUtils.hasErrors(validationResults)) {

             throw new DataValidationErrorException("Validation error!", validationResults);

         }

         try {

             return processCourseInfo(courseInfo, NodeOperation.CREATE);

         } catch (AssemblyException e) {

             LOG.error("Error disassembling course", e);

             throw new OperationFailedException("Error disassembling course");

         } catch (Exception e){

                 LOG.error("Error disassembling course", e);

                 throw new OperationFailedException("Error disassembling course");

         }

     }

     @Override

     @Transactional(readOnly=false)

         public CourseInfo updateCourse(CourseInfo courseInfo) throws DataValidationErrorException, DoesNotExistException, InvalidParameterException, MissingParameterException, VersionMismatchException, OperationFailedException, PermissionDeniedException, AlreadyExistsException, CircularRelationshipException, DependentObjectsExistException, UnsupportedActionException, UnsupportedOperationException, CircularReferenceException {

         checkForMissingParameter(courseInfo, "CourseInfo");

         // Validate

         List<ValidationResultInfo> validationResults = validateCourse("OBJECT", courseInfo);

         if (ValidatorUtils.hasErrors(validationResults)) {

             throw new DataValidationErrorException("Validation error!", validationResults);

         }

         try {

             return processCourseInfo(courseInfo, NodeOperation.UPDATE);

         } catch (AssemblyException e) {

             LOG.error("Error disassembling course", e);

             throw new OperationFailedException("Error disassembling course");

         }

     }

     @Override

     @Transactional(readOnly=false)

         public StatusInfo deleteCourse(String courseId) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException, VersionMismatchException, DataValidationErrorException, AlreadyExistsException, CircularRelationshipException, DependentObjectsExistException, UnsupportedActionException, UnsupportedOperationException, CircularReferenceException {

         try {

             CourseInfo course = getCourse(courseId);

             processCourseInfo(course, NodeOperation.DELETE);

             StatusInfo status = new StatusInfo();

             status.setSuccess(true);

             return status;

         } catch (AssemblyException e) {

             LOG.error("Error disassembling course", e);

             throw new OperationFailedException("Error disassembling course");

         }

     }

     @Override

     public CourseInfo getCourse(String courseId) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException {

         CluInfo clu = luService.getClu(courseId);

         CourseInfo course;

         try {

             course = courseAssembler.assemble(clu, null, false);

         } catch (AssemblyException e) {

             LOG.error("Error assembling course", e);

             throw new OperationFailedException("Error assembling course");

         }

         return course;

     }

     @Override

     public List<ActivityInfo> getCourseActivities(String formatId) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException {

         throw new UnsupportedOperationException("GetCourseActivities");

     }

     @Override

     public List<FormatInfo> getCourseFormats(String courseId) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException {

         throw new UnsupportedOperationException("GetCourseFormats");

     }

     @Override

     public List<LoDisplayInfo> getCourseLos(String courseId) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException {

         throw new UnsupportedOperationException("GetCourseLos");

     }

     @Override

     public List<StatementTreeViewInfo> getCourseStatements(String courseId, String nlUsageTypeKey, String language) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException {

             checkForMissingParameter(courseId, "courseId");

             CluInfo clu = luService.getClu(courseId);

                 if (!CourseAssemblerConstants.COURSE_TYPE.equals(clu.getType())) {

                         throw new DoesNotExistException("Specified CLU is not a Course");

                 }

                 List<RefStatementRelationInfo> relations = statementService.getRefStatementRelationsByRef(CourseAssemblerConstants.COURSE_TYPE, clu.getId());

                 if (relations == null) {

                         return new ArrayList<StatementTreeViewInfo>(0);

                 }

                 List<StatementTreeViewInfo> tree = new ArrayList<StatementTreeViewInfo>(relations.size());

                 for (RefStatementRelationInfo relation : relations) {

                         tree.add(statementService.getStatementTreeView(relation.getStatementId()));

                 }

             return tree;

     }

     @Override

     public List<ValidationResultInfo> validateCourse(String validationType, CourseInfo courseInfo) throws InvalidParameterException, MissingParameterException, OperationFailedException {

         ObjectStructureDefinition objStructure = this.getObjectStructure(CourseInfo.class.getName());

         Validator defaultValidator = validatorFactory.getValidator();

         List<ValidationResultInfo> validationResults = defaultValidator.validateObject(courseInfo, objStructure);

         return validationResults;

     }

     @Override

     @Transactional(readOnly=false)

         public StatementTreeViewInfo createCourseStatement(String courseId, StatementTreeViewInfo statementTreeViewInfo) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException, DataValidationErrorException {

             checkForMissingParameter(courseId, "courseId");

             checkForMissingParameter(statementTreeViewInfo, "statementTreeViewInfo");

         // Validate

         List<ValidationResultInfo> validationResults = validateCourseStatement(courseId, statementTreeViewInfo);

         if (ValidatorUtils.hasErrors(validationResults)) {

             throw new DataValidationErrorException("Validation error!", validationResults);

         }

         if (findStatementReference(courseId, statementTreeViewInfo) != null) {

                 throw new InvalidParameterException("Statement is already referenced by this course");

         }

                 try {

                         StatementTreeViewInfo tree = statementService.createStatementTreeView(statementTreeViewInfo);

                         RefStatementRelationInfo relation = new RefStatementRelationInfo();

                         relation.setRefObjectId(courseId);

                         relation.setRefObjectTypeKey(CourseAssemblerConstants.COURSE_TYPE);

                         relation.setStatementId(tree.getId());

                 relation.setType(CourseAssemblerConstants.COURSE_REFERENCE_TYPE);

                 relation.setState(CourseAssemblerConstants.ACTIVE);

                         statementService.createRefStatementRelation(relation);

                 } catch (Exception e) {

                         throw new OperationFailedException("Unable to create clu/tree relation", e);

                 }

             return statementTreeViewInfo;

     }

         @Override

     @Transactional(readOnly=false)

         public StatusInfo deleteCourseStatement(String courseId, StatementTreeViewInfo statementTreeViewInfo) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException {

             checkForMissingParameter(courseId, "courseId");

             checkForMissingParameter(statementTreeViewInfo, "statementTreeViewInfo");

             RefStatementRelationInfo relation = findStatementReference(courseId, statementTreeViewInfo);

             if (relation != null) {

                     statementService.deleteRefStatementRelation(relation.getId());

                     statementService.deleteStatementTreeView(statementTreeViewInfo.getId());

                     StatusInfo result = new StatusInfo();

                     return result;

             }

             throw new DoesNotExistException("Course does not have this StatemenTree");

         }

     @Override

     @Transactional(readOnly=false)

         public StatementTreeViewInfo updateCourseStatement(String courseId, StatementTreeViewInfo statementTreeViewInfo) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, PermissionDeniedException, DataValidationErrorException, CircularReferenceException, VersionMismatchException {

             checkForMissingParameter(courseId, "courseId");

             checkForMissingParameter(statementTreeViewInfo, "statementTreeViewInfo");

         // Validate

         List<ValidationResultInfo> validationResults = validateCourseStatement(courseId, statementTreeViewInfo);

         if (ValidatorUtils.hasErrors(validationResults)) {

             throw new DataValidationErrorException("Validation error!", validationResults);

         }

         if (findStatementReference(courseId, statementTreeViewInfo) == null) {

                 throw new InvalidParameterException("Statement is not part of this course");

         }

         return statementService.updateStatementTreeView(statementTreeViewInfo.getId(), statementTreeViewInfo);

     }

     @Override

     public List<ValidationResultInfo> validateCourseStatement(String courseId, StatementTreeViewInfo statementTreeViewInfo) throws InvalidParameterException, MissingParameterException, OperationFailedException {

             checkForMissingParameter(courseId, "courseId");

             checkForMissingParameter(statementTreeViewInfo, "statementTreeViewInfo");

             try {

                         CluInfo clu = luService.getClu(courseId);

                 } catch (DoesNotExistException e) {

                         throw new InvalidParameterException("course does not exist");

                 }

             ObjectStructureDefinition objStructure = this.getObjectStructure(StatementTreeViewInfo.class.getName());

         Validator defaultValidator = validatorFactory.getValidator();

         List<ValidationResultInfo> validationResults = defaultValidator.validateObject(statementTreeViewInfo, objStructure);

         return validationResults;

     }   

     @Override

     public ObjectStructureDefinition getObjectStructure(String objectTypeKey) {

         return dictionaryServiceDelegate.getObjectStructure(objectTypeKey);

     }

     @Override

     public List<String> getObjectTypes() {

         return dictionaryServiceDelegate.getObjectTypes();

     }

     public CourseAssembler getCourseAssembler() {

         return courseAssembler;

     }

     public void setCourseAssembler(CourseAssembler courseAssembler) {

         this.courseAssembler = courseAssembler;

     }

     public BusinessServiceMethodInvoker getCourseServiceMethodInvoker() {

         return courseServiceMethodInvoker;

     }

     public void setCourseServiceMethodInvoker(BusinessServiceMethodInvoker courseServiceMethodInvoker) {

         this.courseServiceMethodInvoker = courseServiceMethodInvoker;

     }

     public DictionaryService getDictionaryServiceDelegate() {

         return dictionaryServiceDelegate;

     }

     public void setDictionaryServiceDelegate(DictionaryService dictionaryServiceDelegate) {

         this.dictionaryServiceDelegate = dictionaryServiceDelegate;

     }

     private CourseInfo processCourseInfo(CourseInfo courseInfo, NodeOperation operation) throws AssemblyException, OperationFailedException, VersionMismatchException, PermissionDeniedException, MissingParameterException, InvalidParameterException, DoesNotExistException, DataValidationErrorException, AlreadyExistsException, CircularRelationshipException, DependentObjectsExistException, UnsupportedActionException, UnsupportedOperationException, CircularReferenceException {

         BaseDTOAssemblyNode<CourseInfo, CluInfo> results = courseAssembler.disassemble(courseInfo, operation);

         // Use the results to make the appropriate service calls here

                 courseServiceMethodInvoker.invokeServiceCalls(results);

         return results.getBusinessDTORef();

     }

     public ValidatorFactory getValidatorFactory() {

                 return validatorFactory;

         }

         public void setValidatorFactory(ValidatorFactory validatorFactory) {

                 this.validatorFactory = validatorFactory;

         }

         public LuService getLuService() {

         return luService;

     }

     public void setLuService(LuService luService) {

         this.luService = luService;

     }

         public StatementService getStatementService() {

                 return statementService;

         }

         public void setStatementService(StatementService statementService) {

                 this.statementService = statementService;

         }

         @Override

         @Transactional(readOnly=false)

         public CourseInfo createNewCourseVersion(String versionIndCourseId,

                         String versionComment) throws DataValidationErrorException,

                         DoesNotExistException, InvalidParameterException,

                         MissingParameterException, OperationFailedException,

                         PermissionDeniedException, VersionMismatchException {

                 //step one, get the original course

                 VersionDisplayInfo currentVersion = luService.getCurrentVersion(LuServiceConstants.CLU_NAMESPACE_URI, versionIndCourseId);

                 CourseInfo originalCourse = getCourse(currentVersion.getId());

                 //Version the Clu

                 CluInfo newVersionClu = luService.createNewCluVersion(versionIndCourseId, versionComment);

                 try {

                 BaseDTOAssemblyNode<CourseInfo, CluInfo> results;

                 //Integrate changes into the original course. (should this just be just the id?)

                         courseAssembler.assemble(newVersionClu, originalCourse, true);

                         //Clear Ids from the original course

                         resetIds(originalCourse);

                         //Disassemble the new course

                         results = courseAssembler.disassemble(originalCourse, NodeOperation.UPDATE);

                         // Use the results to make the appropriate service calls here

                         courseServiceMethodInvoker.invokeServiceCalls(results);

                         //copy statements

                         List<StatementTreeViewInfo> statementTreeViews = getCourseStatements(currentVersion.getId(),null,null);

                         clearStatementTreeViewIds(statementTreeViews);

                         for(StatementTreeViewInfo statementTreeView:statementTreeViews){

                                 createCourseStatement(results.getBusinessDTORef().getId(), statementTreeView);

                         }

                         return results.getBusinessDTORef();

                 } catch (AlreadyExistsException e) {

                         throw new OperationFailedException("Error creating new course version",e);

                 } catch (DependentObjectsExistException e) {

                         throw new OperationFailedException("Error creating new course version",e);

                 } catch (CircularRelationshipException e) {

                         throw new OperationFailedException("Error creating new course version",e);

                 } catch (UnsupportedActionException e) {

                         throw new OperationFailedException("Error creating new course version",e);

                 } catch (AssemblyException e) {

                         throw new OperationFailedException("Error creating new course version",e);

                 } catch (UnsupportedOperationException e) {

                         throw new OperationFailedException("Error creating new course version",e);

                 } catch (CircularReferenceException e) {

                         throw new OperationFailedException("Error creating new course version",e);

                 }

         }

         private void clearStatementTreeViewIds(

                         List<StatementTreeViewInfo> statementTreeViews) throws OperationFailedException {

                 for(StatementTreeViewInfo statementTreeView:statementTreeViews){

                         clearStatementTreeViewIdsRecursively(statementTreeView);

                 }

         }

         private void clearStatementTreeViewIdsRecursively(StatementTreeViewInfo statementTreeView) throws OperationFailedException{

                 statementTreeView.setId(null);

                 for(ReqComponentInfo reqComp:statementTreeView.getReqComponents()){

                         reqComp.setId(null);

                         for(ReqCompFieldInfo field:reqComp.getReqCompFields()){

                                 field.setId(null);

                                 //copy any clusets that are adhoc'd and set the field value to the new cluset

                                 if(ReqComponentFieldTypes.COURSE_CLUSET_KEY.getId().equals(field.getType())||

                                    ReqComponentFieldTypes.PROGRAM_CLUSET_KEY.getId().equals(field.getType())||

                                    ReqComponentFieldTypes.CLUSET_KEY.getId().equals(field.getType())){

                                         try {

                                                 CluSetInfo cluSet = luService.getCluSetInfo(field.getValue());

                                                 cluSet.setId(null);

                                                 //Clear clu ids if membership info exists, they will be re-added based on membership info 

                                                 if (cluSet.getMembershipQuery() != null){

                                                         cluSet.getCluIds().clear();

                                                         cluSet.getCluSetIds().clear();

                                                 }

                                                 cluSet = luService.createCluSet(cluSet.getType(), cluSet);

                                                 field.setValue(cluSet.getId());

                                         } catch (Exception e) {

                                                 throw new OperationFailedException("Error copying clusets.", e);

                                         }

                                 }

                         }

                 }

                 for(StatementTreeViewInfo child: statementTreeView.getStatements()){

                         clearStatementTreeViewIdsRecursively(child);

                 }

         }

         private void resetIds(CourseInfo course) {

                 //Clear/Reset Joint info ids

                 for(CourseJointInfo joint:course.getJoints()){

                         joint.setRelationId(null);

                 }

                 //Clear Los

                 for(LoDisplayInfo lo:course.getCourseSpecificLOs()){

                         resetLoRecursively(lo);

                 }

                 //Clear format/activity ids

                 for(FormatInfo format:course.getFormats()){

                         format.setId(null);

                         for(ActivityInfo activity:format.getActivities()){

                                 activity.setId(null);

                         }

                 }

         }

         private void resetLoRecursively(LoDisplayInfo lo){

                 lo.getLoInfo().setId(null);

                 for(LoDisplayInfo nestedLo:lo.getLoDisplayInfoList()){

                         resetLoRecursively(nestedLo);

                 }

         }

         @Override

         @Transactional(readOnly=false)

         public StatusInfo setCurrentCourseVersion(String courseVersionId,

                         Date currentVersionStart) throws DoesNotExistException,

                         InvalidParameterException, MissingParameterException,

                         IllegalVersionSequencingException, OperationFailedException,

                         PermissionDeniedException {

                 return luService.setCurrentCluVersion(courseVersionId, currentVersionStart);

         }

         @Override

         public VersionDisplayInfo getCurrentVersion(String refObjectTypeURI,

                         String refObjectId) throws DoesNotExistException,

                         InvalidParameterException, MissingParameterException,

                         OperationFailedException, PermissionDeniedException {

                 if(CourseServiceConstants.COURSE_NAMESPACE_URI.equals(refObjectTypeURI)){

                         return luService.getCurrentVersion(LuServiceConstants.CLU_NAMESPACE_URI, refObjectId);

                 }

                 throw new InvalidParameterException("Object type: " + refObjectTypeURI + " is not known to this implementation");

         }

         @Override

         public VersionDisplayInfo getCurrentVersionOnDate(String refObjectTypeURI,

                         String refObjectId, Date date) throws DoesNotExistException,

                         InvalidParameterException, MissingParameterException,

                         OperationFailedException, PermissionDeniedException {

                 if(CourseServiceConstants.COURSE_NAMESPACE_URI.equals(refObjectTypeURI)){

                         return luService.getCurrentVersionOnDate(LuServiceConstants.CLU_NAMESPACE_URI, refObjectId, date);

                 }

                 throw new InvalidParameterException("Object type: " + refObjectTypeURI + " is not known to this implementation");

         }

         @Override

         public VersionDisplayInfo getFirstVersion(String refObjectTypeURI,

                         String refObjectId) throws DoesNotExistException,

                         InvalidParameterException, MissingParameterException,

                         OperationFailedException, PermissionDeniedException {

                 if(CourseServiceConstants.COURSE_NAMESPACE_URI.equals(refObjectTypeURI)){

                         return luService.getFirstVersion(LuServiceConstants.CLU_NAMESPACE_URI, refObjectId);

                 }

                 throw new InvalidParameterException("Object type: " + refObjectTypeURI + " is not known to this implementation");

         }

         @Override

         public VersionDisplayInfo getLatestVersion(String refObjectTypeURI,

                         String refObjectId) throws DoesNotExistException,

                         InvalidParameterException, MissingParameterException,

                         OperationFailedException, PermissionDeniedException {

                 if(CourseServiceConstants.COURSE_NAMESPACE_URI.equals(refObjectTypeURI)){

                         return luService.getLatestVersion(LuServiceConstants.CLU_NAMESPACE_URI, refObjectId);

                 }

                 throw new InvalidParameterException("Object type: " + refObjectTypeURI + " is not known to this implementation");

         }

         @Override

         public VersionDisplayInfo getVersionBySequenceNumber(

                         String refObjectTypeURI, String refObjectId, Long sequence)

                         throws DoesNotExistException, InvalidParameterException,

                         MissingParameterException, OperationFailedException,

                         PermissionDeniedException {

                 if(CourseServiceConstants.COURSE_NAMESPACE_URI.equals(refObjectTypeURI)){

                         return luService.getVersionBySequenceNumber(LuServiceConstants.CLU_NAMESPACE_URI, refObjectId, sequence);

                 }

                 throw new InvalidParameterException("Object type: " + refObjectTypeURI + " is not known to this implementation");

         }

         @Override

         public List<VersionDisplayInfo> getVersions(String refObjectTypeURI,

                         String refObjectId) throws DoesNotExistException,

                         InvalidParameterException, MissingParameterException,

                         OperationFailedException, PermissionDeniedException {

                 if(CourseServiceConstants.COURSE_NAMESPACE_URI.equals(refObjectTypeURI)){

                         return luService.getVersions(LuServiceConstants.CLU_NAMESPACE_URI, refObjectId);

                 }

                 throw new InvalidParameterException("Object type: " + refObjectTypeURI + " is not known to this implementation");

         }

         @Override

         public List<VersionDisplayInfo> getVersionsInDateRange(

                         String refObjectTypeURI, String refObjectId, Date from, Date to)

                         throws DoesNotExistException, InvalidParameterException,

                         MissingParameterException, OperationFailedException,

                         PermissionDeniedException {

                 if(CourseServiceConstants.COURSE_NAMESPACE_URI.equals(refObjectTypeURI)){

                         return luService.getVersionsInDateRange(LuServiceConstants.CLU_NAMESPACE_URI, refObjectId, from, to);

                 }

                 throw new InvalidParameterException("Object type: " + refObjectTypeURI + " is not known to this implementation");

         }

         /**

          * Check for missing parameter and throw localized exception if missing

          *

          * @param param

          * @param parameter name

          * @throws MissingParameterException

          */

         private void checkForMissingParameter(Object param, String paramName)

                         throws MissingParameterException {

                 if (param == null) {

                         throw new MissingParameterException(paramName + " can not be null");

                 }

         }

         /**

          * @param courseId

          * @param statementTreeViewInfo

          * @return reference exists

          *

          * @throws InvalidParameterException

          * @throws MissingParameterException

          * @throws OperationFailedException

          * @throws DoesNotExistException

          */

         private RefStatementRelationInfo findStatementReference(String courseId,

                         StatementTreeViewInfo statementTreeViewInfo)

                         throws InvalidParameterException, MissingParameterException,

                         OperationFailedException, DoesNotExistException {

                 List<RefStatementRelationInfo> course = statementService.getRefStatementRelationsByRef(CourseAssemblerConstants.COURSE_TYPE, courseId);

                 if (course != null) {

                         for (RefStatementRelationInfo refRelation : course) {

                                 if (refRelation.getStatementId().equals(statementTreeViewInfo.getId())) {

                                         return refRelation;

                                 }

                         }

                 }

                 return null;

         }

 }