@Override
public void addPrice(Integer nrOfHistoricalLectures, BigDecimal price) {
priceManagementBean.setPrice(nrOfHistoricalLectures, price);
}
// it is not specified if we should use a transaction in here
// nevertheless it seams legit to do so, since otherwise in case of an exception we might have
// marked a lecture as paid even if we have not created a bill for it
@TransactionAttribute(TransactionAttributeType.REQUIRED)
@Asynchronous
@Override
public Future<BillDTO> getBillForLecturer(String lecturerName) throws Exception {
BillDTO billDTO = new BillDTO();
billDTO.setLecturerName(lecturerName);
List<BillDTO.BillPerLecture> bills = new LinkedList<>();
billDTO.setBills(bills);
DAOFactory factory = new DAOFactory(em);
List<ILecturer> lecturers = factory.getLecturerDAO().findByName(lecturerName);
if (lecturers == null || lecturers.size() != 1) {
throw new AssignmentException("Unable to uniquely identify the requested lecturer.");
}
ILecturer lecturer = lecturers.get(0);
// the order by is just required to make the unit test work
// in addition the LectureStreamingDAO.findAll method had to be changed (order by clause added)
Query qry =
em.createQuery(
"select distinct l from Lecture l join fetch l.lectureStreaming ls join fetch ls.classrooms c where l.lecturer = :lecturer and l.isPaid = false and ls.status = :status order by ls.id",
Lecture.class)
.setParameter("lecturer", lecturer)
.setParameter("status", LectureStatus.FINISHED);
List<ILecture> unpaidLectures = qry.getResultList();
int cntPaidLectures =
em.createQuery("from Lecture where isPaid = true and lecturer = :lecturer")
.setParameter("lecturer", lecturer)
.getResultList()
.size();
BigDecimal totalPrice = new BigDecimal(0);
System.out.println("Unpaid: " + unpaidLectures.size() + "; Paid: " + cntPaidLectures);
for (ILecture lecture : unpaidLectures) {
BillDTO.BillPerLecture billPerLecture = billDTO.new BillPerLecture();
bills.add(billPerLecture);
billPerLecture.setLectureId(lecture.getId());
billPerLecture.setNumberOfClassrooms(lecture.getLectureStreaming().getClassrooms().size());
BigDecimal streamingCosts = new BigDecimal(0);
int streamingTime =
lecture
.getStreamingTime(); // getDateDiff(lecture.getLectureStreaming().getStart(),
// lecture.getLectureStreaming().getEnd(), TimeUnit.MINUTES);
System.out.println("Lecture: " + lecture.getId() + "; Time: " + streamingTime);
BigDecimal reducedPercentage = new BigDecimal(1);
for (IClassroom classroom : lecture.getLectureStreaming().getClassrooms()) {
BigDecimal costsPerStudent =
classroom.getVirtualSchool().getMOCPlatform().getCostsPerStudent();
System.out.println(
"Classroom: " + classroom.getId() + "; CostsPerStudent: " + costsPerStudent);
// this code makes one important assumption: the platform is going to be the same for every
// classroom this lecture is streamed at
// this is required for calculating the discount for the setupCosts correctly
// however, the assignment doesn't specify how to handle such situations, as usual!
List<Double> discountsList =
em.createQuery(
"select m.discount from Membership m where m.id.lecturer = :lecturer and m.id.mocPlatform = :platform",
Double.class)
.setParameter("lecturer", lecturer)
.setParameter("platform", classroom.getVirtualSchool().getMOCPlatform())
.getResultList();
System.out.print("DiscountListSize: " + discountsList.size());
if (discountsList.size() == 1) {
reducedPercentage = new BigDecimal(1).subtract(BigDecimal.valueOf(discountsList.get(0)));
System.out.print("; ReducedPercentage: " + reducedPercentage);
}
System.out.println();
// naming something costsPerStudent while we must not multiply it with the amount of
// students is so weird
BigDecimal streamingCostsForClassroom =
costsPerStudent.multiply(
new BigDecimal(
streamingTime
/** classroom.getStudentCapacity() */
));
streamingCosts = streamingCosts.add(streamingCostsForClassroom.multiply(reducedPercentage));
System.out.println(
"StreamingCostsForClassroom: "
+ streamingCostsForClassroom
+ "; StreamingCosts: "
+ streamingCosts);
}
BigDecimal setupCosts =
priceManagementBean.getPrice(cntPaidLectures).multiply(reducedPercentage);
billPerLecture.setSetupCosts(setupCosts);
BigDecimal totalCosts = setupCosts.add(streamingCosts);
System.out.println("SetupCosts: " + setupCosts + "; LectureCosts: " + totalCosts);
billPerLecture.setStreamingCosts(streamingCosts);
billPerLecture.setLectureCosts(totalCosts);
cntPaidLectures++;
totalPrice = totalPrice.add(totalCosts);
lecture.setPaid(true);
em.persist(lecture);
}
billDTO.setTotalPrice(totalPrice);
return new AsyncResult<BillDTO>(billDTO);
}
@Override
public void clearPriceCache() {
priceManagementBean.clearCache();
}