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

#include "base_generator.h"

#include <QElapsedTimer>
#include <QVariant>

BaseGenerator::ShouldLogSuccess
BaseGenerator::shouldLogAllSuccesses() const noexcept {
  return [this]() { return true; };
}

BaseGenerator::ShouldLogSuccess
BaseGenerator::shouldLogEveryNPercent(int percent) const noexcept {
  if (percent <= 0) {
    return [this]() { return false; };
  }

  int oldLastPercentage = 0;
  return [this, percent, oldLastPercentage]() mutable {
    if (oldLastPercentage == lastPercentage_) {
      return false;
    }

    oldLastPercentage = lastPercentage_;
    return !bool(lastPercentage_ % percent);
  };
}

BaseGenerator::ShouldLogSuccess
BaseGenerator::shouldLogFirstAndLastPercent() const noexcept {
  return [this]() { return createdRecords_ == 1 || lastPercentage_ == 100; };
}

BaseGenerator::ShouldLogSuccess BaseGenerator::shouldLogEveryNSeconds(
    int seconds, const ShouldLogSuccess &performOtherwise) const noexcept {
  QElapsedTimer timer;
  timer.start();

  return [this, timer, seconds, performOtherwise]() mutable {
    if (timer.elapsed() >= seconds * 1000) {
      timer.restart();
      return true;
    }
    return performOtherwise();
  };
}

BaseGenerator::ShouldLogSuccess
BaseGenerator::defaultShouldLog(int percent, int seconds) const noexcept {
  ShouldLogSuccess first =
      shouldLogEveryNSeconds(seconds, shouldLogFirstAndLastPercent());
  ShouldLogSuccess second = shouldLogEveryNPercent(percent);

  return [first, second]() { return first() || second(); };
}

void BaseGenerator::generateAll(const ShouldLogSuccess &shouldLogSuccess) {
  auto withoutLimit = []() { return true; };

  generateImplementation(withoutLimit, shouldLogSuccess);
}

void BaseGenerator::generateByFillRatio(
    double fillRatio, const ShouldLogSuccess &shouldLogSuccess) {
  fillRatio >= 1.0 ? fillRatio = 1.0 : fillRatio;

  qInfo() << "Limit fill ratio of records to create: " << fillRatio;

  auto shouldContinue = [this, fillRatio]() -> bool {
    double currentFillRatio = lastPercentage_ / 100.0;
    bool shouldContinue = currentFillRatio < fillRatio;
    if (!shouldContinue) {
      qInfo() << "Limit of records to create reached";
    }
    return shouldContinue;
  };

  generateImplementation(shouldContinue, shouldLogSuccess);
};

void BaseGenerator::generateByRecordCount(
    qsizetype totalRecordsToCreate, const ShouldLogSuccess &shouldLogSuccess) {
  int limit = std::min(totalRecordsToCreate, calculateRemainingCapacity());

  qInfo() << "Limit of records to create: " << limit;

  auto shouldContinue = [this, limit]() -> bool {
    bool shouldContinue = createdRecords_ < limit;
    if (!shouldContinue) {
      qInfo() << "Limit of records to create reached";
    }
    return shouldContinue;
  };

  generateImplementation(shouldContinue, shouldLogSuccess);
};

void BaseGenerator::generateImplementation(
    std::function<bool()> shouldContinue,
    std::function<bool()> shouldLogSuccess) {
  maximumRecords_ = calculateRemainingCapacity();
  qInfo() << "The number of records available for creation:" << maximumRecords_;

  qInfo().noquote() << createTemplateMessage() << "Started";

  while (shouldContinue() && prepareData()) {
    bool success;
    RepositoryResult result = createRecord();

    if (!result.success) {
      qWarning().noquote() << createTemplateMessage()
                           << createFailureMessage(result.errorMessage);
      continue;
    }
    ++createdRecords_;
    updatePercentage();

    if (shouldLogSuccess()) {
      qInfo().noquote() << createTemplateMessage() << createSuccessMessage();
    }

    clearStaleData();
  }

  qInfo().noquote() << createTemplateMessage() << "Completed";
}

void BaseGenerator::updatePercentage() {
  int numerator = maximumRecords_ - calculateRemainingCapacity();
  int newPercentage = std::floor(numerator * 100.0 / maximumRecords_);
  lastPercentage_ = std::max(newPercentage, lastPercentage_);
}

QString BaseGenerator::createFailureMessage(const QString &errorMessage) const {
  QString failureMessage = "Failure: Error message:\n\t%1";
  return failureMessage.arg(errorMessage);
}

QString BaseGenerator::createSuccessMessage() const { return "Success"; }

QString BaseGenerator::createTemplateMessage() const {
  auto digitCount = [](int number) {
    if (number == 0) {
      return 1;
    }
    return static_cast<int>(std::log10(std::abs(number))) + 1;
  };

  int maximumRecordsValue = calculateRemainingCapacity();
  int newFieldWidth =
      std::max(digitCount(createdRecords_), digitCount(maximumRecordsValue));
  fieldWidth_ = std::max(fieldWidth_, newFieldWidth);

  static constexpr int progressBarSize = 25;
  static constexpr int progressBarStep = 100 / progressBarSize;
  const QString progressBar(lastPercentage_ / progressBarStep, QChar('#'));

  return QString("Creating records of entity %1 [ %2 <~ %3] [%4]:")
      .arg(entityName_)
      .arg(createdRecords_, fieldWidth_, 10, QChar(' '))
      .arg(maximumRecordsValue, fieldWidth_, 10, QChar(' '))
      .arg(progressBar.leftJustified(progressBarSize, QChar(' ')));
};