@Override
  public List<PerformanceReport> getTopFiltered(TopPerformancesFilter filter,
                                                Pageable pageRequest) {
    CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder();
    CriteriaQuery<PerformanceReport>
        criteriaQuery =
        criteriaBuilder.createQuery(PerformanceReport.class);
    Root<Performance> performanceRoot = criteriaQuery.from(Performance.class);
    Join<Performance, Show> performanceShowJoin = performanceRoot.join("shows");
    Join<Show, Ticket> showTicketJoin = performanceShowJoin.join("tickets");
    Join<Ticket, TicketIdentifier>
        ticketTicketIdentifierJoin =
        showTicketJoin.join("ticketIdentifiers");
    // Select.
    criteriaQuery.select(criteriaBuilder
        .construct(PerformanceReport.class, performanceRoot.get("id"), performanceRoot.get("name"),
            criteriaBuilder.count(performanceRoot.get("id")).as(Integer.class)));
    // Prepare predicates.
    ArrayList<Predicate> predicates = new ArrayList<>();
    // FIXME: Sold ticket <=> ticketIdentifier.valid = true?
    predicates.add(criteriaBuilder.equal(ticketTicketIdentifierJoin.get("valid"), true));
    // Date filter.
    if (filter.getDateFrom() != null) {
      predicates.add(criteriaBuilder
          .greaterThanOrEqualTo(performanceShowJoin.get("dateOfPerformance"),
              filter.getDateFrom()));
    }
    if (filter.getDateTo() != null) {
      predicates.add(criteriaBuilder.lessThanOrEqualTo(performanceShowJoin.get("dateOfPerformance"),
          filter.getDateTo()));
    }
    // Apply the constraints.
    criteriaQuery.where(predicates.toArray(new Predicate[]{}));
    // Group by performanceId and order by number of sold tickets.
    criteriaQuery.groupBy(performanceRoot.get("id"));
    criteriaQuery.orderBy(criteriaBuilder.desc(criteriaBuilder.count(performanceRoot.get("id"))));
    // Create a query.
    TypedQuery<PerformanceReport> query = em.createQuery(criteriaQuery);
    // Optional pagination.
    if (pageRequest != null) {
      query.setFirstResult(pageRequest.getPageNumber() * pageRequest.getPageSize());
      query.setMaxResults(pageRequest.getPageSize());
    }
    // Run!
    return query.getResultList();
  }