/** Method called by the scheduledInvocationManager */
  public void execute(String opaqueContext) {
    try {
      // for group assignments, we need to have a user ID, otherwise, an exception is thrown:
      sessionManager.getCurrentSession().setUserEid("admin");
      sessionManager.getCurrentSession().setUserId("admin");
      Assignment assignment = assignmentService.getAssignment(opaqueContext);
      if (assignment.getAllowPeerAssessment() && !assignment.getDraft()) {
        int numOfReviews = assignment.getPeerAssessmentNumReviews();
        List<AssignmentSubmission> submissions =
            (List<AssignmentSubmission>) assignmentService.getSubmissions(assignment);
        // keep a map of submission ids to look up possible existing peer assessments
        Map<String, AssignmentSubmission> submissionIdMap =
            new HashMap<String, AssignmentSubmission>();
        // keep track of who has been assigned an assessment
        Map<String, Map<String, PeerAssessmentItem>> assignedAssessmentsMap =
            new HashMap<String, Map<String, PeerAssessmentItem>>();
        // keep track of how many assessor's each student has
        Map<String, Integer> studentAssessorsMap = new HashMap<String, Integer>();
        List<User> submitterUsersList =
            (List<User>) assignmentService.allowAddSubmissionUsers(assignment.getReference());
        List<String> submitterIdsList = new ArrayList<String>();
        if (submitterUsersList != null) {
          for (User u : submitterUsersList) {
            submitterIdsList.add(u.getId());
          }
        }
        // loop through the assignment submissions and setup the maps and lists
        for (AssignmentSubmission s : submissions) {
          if (s.getTimeSubmitted() != null
              // check if the submission is submitted, if not, see if there is any submission data
              // to review (i.e. draft was auto submitted)
              && (s.getSubmitted()
                  || ((s.getSubmittedText() != null && !"".equals(s.getSubmittedText().trim())
                      || (s.getSubmittedAttachments() != null
                          && s.getSubmittedAttachments().size() > 0))))
              && submitterIdsList.contains(s.getSubmitterId())
              && !"admin".equals(s.getSubmitterId())) {
            // only deal with users in the submitter's list
            submissionIdMap.put(s.getId(), s);
            assignedAssessmentsMap.put(
                s.getSubmitterId(), new HashMap<String, PeerAssessmentItem>());
            studentAssessorsMap.put(s.getSubmitterId(), 0);
          }
        }
        // this could be an update to an existing assessment... just make sure to grab any existing
        // review items first
        List<PeerAssessmentItem> existingItems =
            getPeerAssessmentItems(submissionIdMap.keySet(), assignment.getContent().getFactor());
        List<PeerAssessmentItem> removeItems = new ArrayList<PeerAssessmentItem>();
        // remove all empty items to start from scratch:
        for (Iterator iterator = existingItems.iterator(); iterator.hasNext(); ) {
          PeerAssessmentItem peerAssessmentItem = (PeerAssessmentItem) iterator.next();
          if (peerAssessmentItem.getScore() == null
              && (peerAssessmentItem.getComment() == null
                  || "".equals(peerAssessmentItem.getComment().trim()))) {
            removeItems.add(peerAssessmentItem);
            iterator.remove();
          }
        }
        if (removeItems.size() > 0) {
          getHibernateTemplate().deleteAll(removeItems);
        }
        // loop through the items and update the map values:
        for (PeerAssessmentItem p : existingItems) {
          if (submissionIdMap.containsKey(p.getSubmissionId())) {
            // first, add this assessment to the AssignedAssessmentsMap
            AssignmentSubmission s = submissionIdMap.get(p.getSubmissionId());
            // Next, increment the count for studentAssessorsMap
            Integer count = studentAssessorsMap.get(s.getSubmitterId());
            if (count == null) {
              // probably not possible, just check
              count = 0;
            }
            // check if the count is less than num of reviews before added another one,
            // otherwise, we need to delete this one (if it's empty)
            if (count < numOfReviews || p.getScore() != null || p.getComment() != null) {
              count++;
              studentAssessorsMap.put(s.getSubmitterId(), count);
              Map<String, PeerAssessmentItem> peerAssessments =
                  assignedAssessmentsMap.get(p.getAssessorUserId());
              if (peerAssessments == null) {
                // probably not possible, but just check
                peerAssessments = new HashMap<String, PeerAssessmentItem>();
              }
              peerAssessments.put(p.getSubmissionId(), p);
              assignedAssessmentsMap.put(p.getAssessorUserId(), peerAssessments);
            } else {
              // this shoudln't happen since the code above removes all empty assessments, but just
              // in case:
              getHibernateTemplate().delete(p);
            }
          } else {
            // this isn't realy possible since we looked up the peer assessments by submission id
            log.error(
                "AssignmentPeerAssessmentServiceImpl: found a peer assessment with an invalid session id: "
                    + p.getSubmissionId());
          }
        }

        // ok now that we have any existing assigned reviews accounted for, let's make sure that the
        // number of reviews is setup properly,
        // if not, add some
        // let's get a random order of submission IDs so we can have a random assigning algorithm
        List<String> randomSubmissionIds = new ArrayList<String>(submissionIdMap.keySet());
        Collections.shuffle(randomSubmissionIds);
        List<PeerAssessmentItem> newItems = new ArrayList<PeerAssessmentItem>();
        int i = 0;
        for (String submissionId : randomSubmissionIds) {
          AssignmentSubmission s = submissionIdMap.get(submissionId);
          // first find out how many existing items exist for this user:
          Integer assignedCount = studentAssessorsMap.get(s.getSubmitterId());
          // by creating a tailing list (snake style), we eliminate the issue where you can be stuck
          // with
          // a submission and the same submission user left, making for uneven distributions of
          // submission reviews
          List<String> snakeSubmissionList =
              new ArrayList<String>(randomSubmissionIds.subList(i, randomSubmissionIds.size()));
          if (i > 0) {
            snakeSubmissionList.addAll(new ArrayList<String>(randomSubmissionIds.subList(0, i)));
          }
          while (assignedCount < numOfReviews) {
            // we need to add more reviewers for this user's submission
            String lowestAssignedAssessor =
                findLowestAssignedAssessor(
                    assignedAssessmentsMap,
                    s.getSubmitterId(),
                    submissionId,
                    snakeSubmissionList,
                    submissionIdMap);
            if (lowestAssignedAssessor != null) {
              Map<String, PeerAssessmentItem> assessorsAssessmentMap =
                  assignedAssessmentsMap.get(lowestAssignedAssessor);
              if (assessorsAssessmentMap == null) {
                assessorsAssessmentMap = new HashMap<String, PeerAssessmentItem>();
              }
              PeerAssessmentItem newItem = new PeerAssessmentItem();
              newItem.setAssessorUserId(lowestAssignedAssessor);
              newItem.setSubmissionId(submissionId);
              newItem.setAssignmentId(assignment.getId());
              newItems.add(newItem);
              assessorsAssessmentMap.put(submissionId, newItem);
              assignedAssessmentsMap.put(lowestAssignedAssessor, assessorsAssessmentMap);
              // update this submission user's count:
              assignedCount++;
              studentAssessorsMap.put(submissionId, assignedCount);
            } else {
              break;
            }
          }
          i++;
        }
        if (newItems.size() > 0) {
          getHibernateTemplate().saveOrUpdateAll(newItems);
        }
      }
    } catch (IdUnusedException e) {
      log.error(e.getMessage(), e);
    } catch (PermissionException e) {
      log.error(e.getMessage(), e);
    } finally {
      sessionManager.getCurrentSession().setUserEid(null);
      sessionManager.getCurrentSession().setUserId(null);
    }
  }
 public boolean updateScore(String submissionId) {
   boolean saved = false;
   SecurityAdvisor sa =
       new SecurityAdvisor() {
         public SecurityAdvice isAllowed(String userId, String function, String reference) {
           if (AssignmentService.SECURE_GRADE_ASSIGNMENT_SUBMISSION.equals(function)
               || AssignmentService.SECURE_UPDATE_ASSIGNMENT.equals(function)
               || AssignmentService.SECURE_ACCESS_ASSIGNMENT.equals(function)
               || AssignmentService.SECURE_ACCESS_ASSIGNMENT_SUBMISSION.equals(function)) {
             return SecurityAdvice.ALLOWED;
           } else {
             return SecurityAdvice.PASS;
           }
         }
       };
   try {
     securityService.pushAdvisor(sa);
     // first check that submission exists and that it can be graded/override score
     AssignmentSubmission submission = assignmentService.getSubmission(submissionId);
     // only override grades that have never been graded or was last graded by this service
     // this prevents this service from overriding instructor set grades, which take precedent.
     if (submission != null
         && (submission.getGraded() == false
             || submission.getGradedBy() == null
             || "".equals(submission.getGradedBy().trim())
             || AssignmentPeerAssessmentService.class
                 .getName()
                 .equals(submission.getGradedBy().trim()))) {
       List<PeerAssessmentItem> items =
           getPeerAssessmentItems(
               submissionId, submission.getAssignment().getContent().getFactor());
       if (items != null) {
         // scores are stored w/o decimal points, so a score of 3.4 is stored as 34 in the DB
         // add all the scores together and divide it by the number of scores added.  Then round.
         Integer totalScore = 0;
         int denominator = 0;
         for (PeerAssessmentItem item : items) {
           if (!item.isRemoved() && item.getScore() != null) {
             totalScore += item.getScore();
             denominator++;
           }
         }
         if (denominator > 0) {
           totalScore = Math.round(totalScore / denominator);
         } else {
           totalScore = null;
         }
         String totleScoreStr = null;
         if (totalScore != null) {
           totleScoreStr = totalScore.toString();
         }
         boolean changed = false;
         if ((totleScoreStr == null || "".equals(totleScoreStr))
             && (submission.getGrade() == null || "".equals(submission.getGrade()))) {
           // scores are both null, nothing changed
         } else if ((totleScoreStr != null && !"".equals(totleScoreStr))
             && (submission.getGrade() == null || "".equals(submission.getGrade()))) {
           // one score changed, update
           changed = true;
         } else if ((totleScoreStr == null || "".equals(totleScoreStr))
             && (submission.getGrade() != null && !"".equals(submission.getGrade()))) {
           // one score changed, update
           changed = true;
         } else if (!totleScoreStr.equals(submission.getGrade())) {
           changed = true;
         }
         if (changed) {
           AssignmentSubmissionEdit edit = assignmentService.editSubmission(submissionId);
           edit.setGrade(totleScoreStr);
           edit.setGraded(true);
           edit.setGradedBy(AssignmentPeerAssessmentService.class.getName());
           edit.setGradeReleased(false);
           assignmentService.commitEdit(edit);
           saved = true;
         }
       }
     }
   } catch (IdUnusedException e) {
     log.error(e.getMessage(), e);
   } catch (InUseException e) {
     log.error(e.getMessage(), e);
   } catch (PermissionException e) {
     log.error(e.getMessage(), e);
   } finally {
     // remove advisor
     if (sa != null) {
       securityService.popAdvisor(sa);
     }
   }
   return saved;
 }