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

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.Comparator;

 import java.util.HashMap;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import java.util.Map.Entry;

 import org.kuali.student.common.util.UUIDHelper;

 import org.kuali.student.core.assembly.BOAssembler;

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

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

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

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

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

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

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

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

 import org.kuali.student.lum.lo.dto.LoCategoryInfo;

 import org.kuali.student.lum.lo.dto.LoInfo;

 import org.kuali.student.lum.lo.dto.LoLoRelationInfo;

 import org.kuali.student.lum.lo.service.LearningObjectiveService;

 public class LoAssembler implements BOAssembler<LoDisplayInfo, LoInfo> {

         private LearningObjectiveService loService;

         @Override

         public LoDisplayInfo assemble(LoInfo lo, LoDisplayInfo loDisplayInfo,

                         boolean shallowBuild) throws AssemblyException {

                 LoDisplayInfo loDisplay = (null != loDisplayInfo) ? loDisplayInfo : new LoDisplayInfo();

                 loDisplay.setLoInfo(lo);

                 if (!shallowBuild) {

                         String loId = lo.getId();

                         try {

                                 List<LoCategoryInfo> loCategories = loService.getLoCategoriesForLo(loId);

                                 loDisplay.setLoCategoryInfoList(loCategories);

                         } catch (DoesNotExistException e) {

                         } catch (Exception e) {

                                 throw new AssemblyException("Error getting learning objective categories", e);

                         }

                         try {

                                 List<LoInfo> childLos = loService.getRelatedLosByLoId(loId,CourseAssemblerConstants.COURSE_LO_RELATION_INCLUDES);

                                 for(LoInfo childLo:childLos){

                                         LoDisplayInfo childLoDisplay = assemble(childLo, null, shallowBuild);

                                         childLoDisplay.setParentLoRelationid(lo.getId());

                                         childLoDisplay.setParentRelType(CourseAssemblerConstants.COURSE_LO_RELATION_INCLUDES);

                                         loDisplay.getLoDisplayInfoList().add(childLoDisplay);

                                 }

                                 if(loDisplay.getLoDisplayInfoList().size()>1){

                                         Collections.sort(loDisplay.getLoDisplayInfoList(), LoDisplayComparator.getInstance());

                                 }

                         } catch (DoesNotExistException e) {

                         } catch (Exception e) {

                                 throw new AssemblyException("Error getting learning objective", e);

                         }

                 }

                 return loDisplay;

         }

         @Override

         //Creation of categories is done in the LoCategoryRpcGwtServlet

         public BaseDTOAssemblyNode<LoDisplayInfo, LoInfo> disassemble(

                         LoDisplayInfo loDisplay, NodeOperation operation)

                         throws AssemblyException {

                 BaseDTOAssemblyNode<LoDisplayInfo, LoInfo> result = new BaseDTOAssemblyNode<LoDisplayInfo, LoInfo>(this);

                 //see if this is a new LuInfo

                 if (loDisplay == null || loDisplay.getLoInfo() == null) {

                         throw new AssemblyException("Lo can not be null");

                 }

                 if (NodeOperation.CREATE != operation && null == loDisplay.getLoInfo().getId()) {

                         throw new AssemblyException("Lo id can not be null");

                 }

                 //set the id if it's not there already(important for creating relations)

                 loDisplay.getLoInfo().setId(UUIDHelper.genStringUUID(loDisplay.getLoInfo().getId()));

                 //Default these values

                 loDisplay.getLoInfo().setType(CourseAssemblerConstants.COURSE_LO_TYPE);

                 loDisplay.getLoInfo().setLoRepositoryKey(CourseAssemblerConstants.COURSE_LO_REPOSITORY_KEY);

                 //Populate the node

                 result.setBusinessDTORef(loDisplay);

                 result.setNodeData(loDisplay.getLoInfo());

                 result.setOperation(operation);

                 //Process the child los

                 try {

                         List<BaseDTOAssemblyNode<?, ?>> childLoNodes = disassembleChildLos(loDisplay, operation);

                         result.getChildNodes().addAll(childLoNodes);

                 } catch (DoesNotExistException e) {

                 } catch (Exception e) {

                         throw new AssemblyException("Error disassembling child los", e);

                 } 

                 //Process the categories

                 try {

                         List<BaseDTOAssemblyNode<?, ?>> categoryNodes = disassembleCategories(loDisplay, operation);

                         result.getChildNodes().addAll(categoryNodes);

                 } catch (Exception e) {

                         throw new AssemblyException("Error disassembling categories", e);

                 } 

                 return result;

         }

         private List<BaseDTOAssemblyNode<?, ?>> disassembleCategories(

                         LoDisplayInfo loDisplay, NodeOperation operation) throws AssemblyException {

                 List<BaseDTOAssemblyNode<?, ?>> results = new ArrayList<BaseDTOAssemblyNode<?, ?>>();

                 //Category relations

                 Set<String> currentCategoryIds = new HashSet<String>();

                 //Get current relations

                 if (!NodeOperation.CREATE.equals(operation)) {

                         try {

                                 List<LoCategoryInfo> categories = loService.getLoCategoriesForLo(loDisplay.getLoInfo().getId());

                                 for (LoCategoryInfo category : categories) {

                                         currentCategoryIds.add(category.getId());

                                 }

                         } catch (DoesNotExistException e) {

                         } catch (Exception e) {

                                 throw new AssemblyException("Error getting categories",        e);

                         }

                 }

                 //Update

                 for (LoCategoryInfo category : loDisplay.getLoCategoryInfoList()) {

                         // If this is a format create/new activity update then all activities will be created

                     if (NodeOperation.CREATE == operation

                             || (NodeOperation.UPDATE == operation &&  !currentCategoryIds.contains(category.getId()))) {

                             LoCategoryRelationInfo loCategoryRelation = new LoCategoryRelationInfo();

                             loCategoryRelation.setCategoryId(category.getId());

                             loCategoryRelation.setLoId(loDisplay.getLoInfo().getId());

                 BaseDTOAssemblyNode<LoDisplayInfo, LoCategoryRelationInfo> relationToAddNode = new BaseDTOAssemblyNode<LoDisplayInfo, LoCategoryRelationInfo>(null);

                 relationToAddNode.setNodeData(loCategoryRelation);

                 relationToAddNode.setOperation(NodeOperation.CREATE);

                 results.add(relationToAddNode);

                 currentCategoryIds.remove(category.getId());

                     } else if (NodeOperation.UPDATE == operation

                                         && currentCategoryIds.contains(category.getId())) {

                 currentCategoryIds.remove(category.getId());

                         } 

                 }

                 //Delete leftovers

                 for(String categoryId:currentCategoryIds){

                     LoCategoryRelationInfo loCategoryRelation = new LoCategoryRelationInfo();

                     loCategoryRelation.setCategoryId(categoryId);

                     loCategoryRelation.setLoId(loDisplay.getLoInfo().getId());

             BaseDTOAssemblyNode<LoDisplayInfo, LoCategoryRelationInfo> relationToDeleteNode = new BaseDTOAssemblyNode<LoDisplayInfo, LoCategoryRelationInfo>(null);

             relationToDeleteNode.setNodeData(loCategoryRelation);

             relationToDeleteNode.setOperation(NodeOperation.DELETE);

             results.add(relationToDeleteNode);

                 }

                 return results;

         }

         private List<BaseDTOAssemblyNode<?, ?>> disassembleChildLos(LoDisplayInfo loDisplay, NodeOperation operation) throws DoesNotExistException, InvalidParameterException, MissingParameterException, OperationFailedException, AssemblyException{

                 List<BaseDTOAssemblyNode<?, ?>> results = new ArrayList<BaseDTOAssemblyNode<?, ?>>();

                 Map<String,LoLoRelationInfo> currentLoRelations = new HashMap<String,LoLoRelationInfo>();

                 //Make lu lu relations

                 if (!NodeOperation.CREATE.equals(operation)) {

                         try {

                                 List<LoLoRelationInfo> loRelations = loService.getLoLoRelationsByLoId(loDisplay.getLoInfo().getId());

                                 for (LoLoRelationInfo loRelation : loRelations) {

                                         //getLoLoRelationsByLoId returns if the lo is related or if it is the owner(this seems wrong)

                                         if(CourseAssemblerConstants.COURSE_LO_RELATION_INCLUDES.equals(loRelation.getType())&&

                                                         !loDisplay.getLoInfo().getId().equals(loRelation.getRelatedLoId())){

                                                 currentLoRelations.put(loRelation.getRelatedLoId(), loRelation);

                                         }

                                 }

                         } catch (DoesNotExistException e) {

                         } catch (Exception e) {

                                 throw new AssemblyException("Error getting categories",        e);

                         }

                 }

                 // Loop through all the activities in this format

                 for (LoDisplayInfo childDisplay : loDisplay.getLoDisplayInfoList()) {

                         // If this is a format create/new activity update then all activities will be created

                     if (NodeOperation.CREATE == operation

                             || (NodeOperation.UPDATE == operation &&  !currentLoRelations.containsKey(childDisplay.getLoInfo().getId()))) {

                 // the lo does not exist, so create

                 // Assemble and add the lo

                             childDisplay.getLoInfo().setId(null);

                 BaseDTOAssemblyNode<LoDisplayInfo, LoInfo> loNode = this

                         .disassemble(childDisplay, NodeOperation.CREATE);

                 results.add(loNode);

                 // Create the relationship and add it as well

                 LoLoRelationInfo relation = new LoLoRelationInfo();

                 relation.setLoId(loDisplay.getLoInfo().getId());

                 relation.setRelatedLoId(loNode.getNodeData().getId());

                 relation.setType(CourseAssemblerConstants.COURSE_LO_RELATION_INCLUDES);

                 relation.setState(loDisplay.getLoInfo().getState());

                 BaseDTOAssemblyNode<LoDisplayInfo, LoLoRelationInfo> relationNode = new BaseDTOAssemblyNode<LoDisplayInfo, LoLoRelationInfo>(

                         null);

                 relationNode.setNodeData(relation);

                 relationNode.setOperation(NodeOperation.CREATE);

                 results.add(relationNode);

             } else if (NodeOperation.UPDATE == operation

                                         && currentLoRelations.containsKey(childDisplay.getLoInfo().getId())) {

                                 // If the lo already has this child lo, then just update the

                                 // child lo

                                 BaseDTOAssemblyNode<LoDisplayInfo, LoInfo> loNode = this

                                                 .disassemble(childDisplay, NodeOperation.UPDATE);

                                 results.add(loNode);

                                 // remove this entry from the map so we can tell what needs to

                                 // be deleted at the end

                                 currentLoRelations.remove(childDisplay.getLoInfo().getId());

                         } else if (NodeOperation.DELETE == operation

                     && currentLoRelations.containsKey(childDisplay.getLoInfo().getId())) {

                 // Delete the Format and its relation

                                 LoLoRelationInfo relationToDelete = currentLoRelations.get(childDisplay.getLoInfo().getId());

                 BaseDTOAssemblyNode<LoDisplayInfo, LoLoRelationInfo> relationToDeleteNode = new BaseDTOAssemblyNode<LoDisplayInfo, LoLoRelationInfo>(

                         null);

                 relationToDeleteNode.setNodeData(relationToDelete);

                 relationToDeleteNode.setOperation(NodeOperation.DELETE);

                 results.add(relationToDeleteNode);

                 BaseDTOAssemblyNode<LoDisplayInfo, LoInfo> loNode = this

                 .disassemble(childDisplay, NodeOperation.DELETE);

                 results.add(loNode);                                

                 // remove this entry from the map so we can tell what needs to

                 // be deleted at the end

                 currentLoRelations.remove(childDisplay.getLoInfo().getId());                            

                         }

                 }         

         // Now any leftover lo ids are no longer needed, so delete

         // los and relations

         for (Entry<String, LoLoRelationInfo> entry : currentLoRelations.entrySet()) {

             // Create a new relation with the id of the relation we want to

             // delete

                 LoLoRelationInfo relationToDelete = entry.getValue();

             BaseDTOAssemblyNode<LoDisplayInfo, LoLoRelationInfo> relationToDeleteNode = new BaseDTOAssemblyNode<LoDisplayInfo, LoLoRelationInfo>(

                     null);

             relationToDeleteNode.setNodeData(relationToDelete);

             relationToDeleteNode.setOperation(NodeOperation.DELETE);

             results.add(relationToDeleteNode);

             LoInfo loToDelete = loService.getLo(entry.getKey());

             LoDisplayInfo loDisplayToDelete = this.assemble(loToDelete, null, false);

             BaseDTOAssemblyNode<LoDisplayInfo, LoInfo> loNode = this.disassemble(loDisplayToDelete, NodeOperation.DELETE);

             results.add(loNode);                                            

         }

                 return results;

         }

         public void setLoService(LearningObjectiveService loService) {

                 this.loService = loService;

         }

         public static class LoDisplayComparator implements Comparator<LoDisplayInfo>{

                 private static LoDisplayComparator instance = new LoDisplayComparator();

                 @Override

                 public int compare(LoDisplayInfo o1, LoDisplayInfo o2) {

                         String o1Sequence = o1.getLoInfo().getAttributes().get(CourseAssemblerConstants.COURSE_LO_SEQUENCE);

                         String o2Sequence = o1.getLoInfo().getAttributes().get(CourseAssemblerConstants.COURSE_LO_SEQUENCE);

                         if(o1Sequence!=null){

                                 return o1Sequence.compareTo(o2Sequence);

                         }else if(o2Sequence!=null){

                                 return -1;

                         }

                         return 0;

                 }

                 public static LoDisplayComparator getInstance() {

                         return instance;

                 }

         }

 }