cinema-ticket-management-system/core/services/session_generator.cpp

#include "session_generator.h"

#include "create_session_request.h"
#include "hall_dto.h"
#include "halls_repository.h"
#include "movie_dto.h"
#include "movies_repository.h"
#include "repository_manager.h"
#include "repository_result.h"
#include "schema_metadata.h"
#include "sessions_repository.h"

SessionGenerator::SessionGenerator(
    const ReservationManager &reservationReference)
    : BaseGenerator("Session"), reservationReference_(reservationReference) {
  initializeRepositories(); // First

  qint32 extraTime = 45;                     // Extra time for cleaning the room
  initializeMovieIdToDurationMap(extraTime); // After initializing repositories

  initializeBounds();     // After initializing movieIdToDuration
  initializeDayManager(); // After initializing bounds
  initializeHallIdToReservationManagerMap(); // After initializing dayManager
}

void SessionGenerator::initializeRepositories() {
  RepositoryManager &repositoryManager = RepositoryManager::instance();
  SchemaMetadata metadata = SchemaMetadata::defaultSchema();

  moviesRepository_ = repositoryManager.getRepositoryAs<MoviesRepository>(
      metadata.repositoryTableName("movies"));
  hallsRepository_ = repositoryManager.getRepositoryAs<HallsRepository>(
      metadata.repositoryTableName("halls"));
  sessionsRepository_ = repositoryManager.getRepositoryAs<SessionsRepository>(
      metadata.repositoryTableName("sessions"));

  if (!bool(moviesRepository_ && hallsRepository_ && sessionsRepository_)) {
    qFatal() << "Failed to initialize repositories";
  }
}

void SessionGenerator::initializeMovieIdToDurationMap(
    qint32 additionalMinutes) {
  QVector<MovieDTO> movies;
  RepositoryResult result = moviesRepository_->getAllMovies(movies);

  if (!result.success) {
    qFatal() << "Failed to retrieve movies";
  }

  for (const MovieDTO &movie : movies) {
    movieIdToDurationMinutes_[movie.movieId()] =
        movie.duration() + additionalMinutes;
  }

  if (movieIdToDurationMinutes_.isEmpty()) {
    qFatal() << "Failed to initialize movieIdToDuration";
  }

  qInfo() << "Number of movies:" << movieIdToDurationMinutes_.size();
}

void SessionGenerator::initializeBounds() {
  qint32 lowerBoundReservationMin = *std::min_element(
      movieIdToDurationMinutes_.cbegin(), movieIdToDurationMinutes_.cend());
  lowerBoundReservationMs_ = lowerBoundReservationMin * 60'000; // 60 * 1000

  qint32 upperBoundReservationMin = *std::max_element(
      movieIdToDurationMinutes_.cbegin(), movieIdToDurationMinutes_.cend());
  upperBoundReservationMs_ = upperBoundReservationMin * 60'000; // 60 * 1000

  qInfo() << "Lower bound reservation in Ms:" << lowerBoundReservationMs_;
  qInfo() << "Upper bound reservation in Ms:" << upperBoundReservationMs_;
}

void SessionGenerator::initializeDayManager() {
  QTime minDuration = QTime::fromMSecsSinceStartOfDay(lowerBoundReservationMs_);
  DayManager dayManager(reservationReference_.reference());
  dayManager.setMinDuration(minDuration);
  reservationReference_.setReference(dayManager);

  if (!reservationReference_.reference().minDuration().isValid()) {
    qFatal() << "Failed to initialize dayManager";
  }

  qInfo() << "Day manager: Min duration:"
          << reservationReference_.reference().minDuration();
  qInfo() << "Day manager: Slot count:"
          << reservationReference_.reference().slotCount();
}

void SessionGenerator::initializeHallIdToReservationManagerMap() {
  QVector<HallDTO> halls;
  RepositoryResult result = hallsRepository_->getAllHalls(halls);

  if (!result.success) {
    qFatal() << "Failed to retrieve halls";
  }

  for (const HallDTO &hall : halls) {
    hallIdToReservationManager_[hall.hallId()] = reservationReference_;
  }

  if (hallIdToReservationManager_.isEmpty()) {
    qFatal() << "Failed to initialize hallIdToReservationManager";
  }

  qInfo() << "Number of halls:" << hallIdToReservationManager_.size();
}

RepositoryResult SessionGenerator::createRecord() {
  CreateSessionRequest request;
  request.setBeginAt(reservationContext_.beginAt);
  request.setHallId(reservationContext_.hallId);
  request.setMovieId(reservationContext_.movieId);
  request.setTicketPrice(reservationContext_.ticketPrice);

  RepositoryResult result = sessionsRepository_->createSession(request);

  return result;
}

QString
SessionGenerator::createFailureMessage(const QString &errorMessage) const {
  QString additionalInfo =
      QString("Additional info: Hall id: %1 Begin at: %2")
          .arg(reservationContext_.hallId)
          .arg(reservationContext_.beginAt.toString("yyyy-MM-dd hh:mm:ss"));
  QString failureMessage = "Failure:\n\t%1\n\tError message: %2";
  return failureMessage.arg(additionalInfo).arg(errorMessage);
}

QString SessionGenerator::createSuccessMessage() const {
  qint32 hallId = reservationContext_.hallId;
  const ReservationManager &manager = hallIdToReservationManager_.value(hallId);
  QTime duration = calculateDuration(reservationContext_);

  // return QString("Success: TAD: %1 TAS: %2 EId: %3 AD: %4 AS: %5 CR: %6 B: %7
  // D: %8")
  return QString("Success: TAD: %1 TAS: %2 EId: %3 AD: %4 AS: %5 CR: %6")
      .arg(calculateAvailableDaysCount())          // Total available days
      .arg(calculateAvailableSlotsCount())         // Total available slots
      .arg(hallId)                                 // Entity id
      .arg(manager.calculateAvailableDaysCount())  // Available days for the
                                                   // current hall
      .arg(manager.calculateAvailableSlotsCount()) // Available slots for the
                                                   // current hall
      .arg(manager.createdRecords());              // Created records for the
                                                   // current hall
  // .arg(reservationContext_.beginAt.toString(   //
  //     "yyyy-MM-dd hh:mm:ss"))                  // Begin
  //                                              // of created record
  // .arg(duration.toString("hh:mm:ss"));         // Duration of created record
}

qsizetype SessionGenerator::calculateRemainingCapacity() const {
  // Maximum number of sessions that can be created
  return std::accumulate(hallIdToReservationManager_.cbegin(),
                         hallIdToReservationManager_.cend(), 0,
                         [&](qsizetype sum, const ReservationManager &manager) {
                           return sum + manager.calculatePossibleReservations(
                                            lowerBoundReservationMs_);
                         });
};

bool SessionGenerator::prepareData() {
  std::random_device rd;
  std::mt19937 g{rd()};

  QList<qint32> hallIds = hallIdToReservationManager_.keys();
  std::shuffle(hallIds.begin(), hallIds.end(), g);
  QList<qint32> movieIds = movieIdToDurationMinutes_.keys();
  std::shuffle(movieIds.begin(), movieIds.end(), g);

  for (qint32 hallId : hallIds) {
    if (prepareData(hallId, movieIds)) {
      return true;
    }
  }
  qWarning() << "No available halls";

  return false;
}

bool SessionGenerator::prepareData(qint32 hallId,
                                   const QList<qint32> &movieIds) {
  for (qint32 movieId : movieIds) {
    ReservationManager &manager = hallIdToReservationManager_[hallId];

    auto [beginDateTime, endTime] = manager.reserve(duration(movieId));
    if (!beginDateTime.isValid() || !endTime.isValid()) {
      continue;
    }

    const QDate epochDate = QDateTime::fromMSecsSinceEpoch(0).date();
    const qint64 deltaDays = epochDate.daysTo(QDate(2025, 1, 1));
    const QDate newBeginDate = beginDateTime.date().addDays(deltaDays);
    const QTime beginTime = beginDateTime.time();

    reservationContext_ = ReservationContext{
        QDateTime(std::move(newBeginDate), std::move(beginTime)),
        std::move(endTime),
        bounded(10'000, 50'000) / 100.0,
        hallId,
        movieId,
    };

    return true;
  }

  qCritical()
      << "SessionGenerator::prepareData: No available movies for hall with id"
      << hallId;

  return false;
}

QTime SessionGenerator::duration(qint32 movieId) const {
  qint32 durationMin = movieIdToDurationMinutes_[movieId];
  qint64 durationMs = durationMin * 60'000; // 60 * 1000
  QTime durationTime = QTime::fromMSecsSinceStartOfDay(durationMs);
  return durationTime;
}

qsizetype SessionGenerator::calculateAvailableDaysCount() const {
  return std::accumulate(hallIdToReservationManager_.cbegin(),
                         hallIdToReservationManager_.cend(), 0,
                         [&](int sum, const ReservationManager &manager) {
                           return sum + manager.calculateAvailableDaysCount();
                         });
}

qsizetype SessionGenerator::calculateAvailableSlotsCount() const {
  return std::accumulate(hallIdToReservationManager_.cbegin(),
                         hallIdToReservationManager_.cend(), 0,
                         [&](int sum, const ReservationManager &manager) {
                           return sum + manager.calculateAvailableSlotsCount();
                         });
}

QTime SessionGenerator::calculateDuration(ReservationContext context) const {
  QTime beginTime = context.beginAt.time();
  QTime endTime = context.endTime;
  qint64 durationMs = beginTime.msecsTo(endTime);
  return QTime::fromMSecsSinceStartOfDay(durationMs);
}

void SessionGenerator::clearStaleData() {
  qint64 hallId = reservationContext_.hallId;
  if (hallIdToReservationManager_[hallId].calculateAvailableDaysCount() == 0) {
    qWarning() << "No available days for hall" << hallId;
    hallIdToReservationManager_.remove(hallId);
  }
}