#ifndef DAY_MANAGER_H
#define DAY_MANAGER_H

#include <QTime>

class DayManager {
public:
  enum class SlotSelectionMode { Maximal, Minimal, Quick, Random };
  enum class StartTimeMode { Left, Random, Right };

private:
  QMap<QTime, QTime> availableSlots_;
  SlotSelectionMode slotSelectionMode_;
  StartTimeMode startTimeMode_;
  qint64 minDurationMs_;
  qsizetype createdRecords_;

public:
  inline DayManager();
  explicit DayManager(const QTime &begin, const QTime &end);

  QPair<QTime, QTime> reserve(const QTime &duration);
  QTime duration() const;
  QTime duration(const QTime &begin) const;
  inline QTime minDuration() const noexcept;
  inline qsizetype createdRecords() const noexcept;
  inline qsizetype slotCount() const;
  inline void setMode(SlotSelectionMode mode);
  inline void setMode(StartTimeMode mode);
  void addAvailableSlot(const QTime &begin, const QTime &end);
  void setMinDuration(const QTime &duration);

  qsizetype calculatePossibleReservations(qint64 requiredMs) const;

private:
  template <typename... Times>
  bool isAvailable(const QTime &first, const Times &...others) const;

  QList<std::reference_wrapper<const QTime>>
  availableSlots(qint64 requiredMs) const;

  QPair<QTime, QTime> reserveAvailableSlot(QTime key, qint64 requiredMs);
  QPair<QTime, QTime> reserveAvailableSlotLeft(QTime key, qint64 requiredMs);
  QPair<QTime, QTime> reserveAvailableSlotRandom(QTime key, qint64 requiredMs);
  QPair<QTime, QTime> reserveAvailableSlotRight(QTime key, qint64 requiredMs);
  QPair<QTime, QTime> reserveImpl(qint64 requiredMs);
  QPair<QTime, QTime> reserveImplMaximal(qint64 requiredMs);
  QPair<QTime, QTime> reserveImplMinimal(qint64 requiredMs);
  QPair<QTime, QTime> reserveImplQuick(qint64 requiredMs);
  QPair<QTime, QTime> reserveImplRandom(qint64 requiredMs);

private:
  friend class DayManagerTest;
};

DayManager::DayManager()
    : slotSelectionMode_(SlotSelectionMode::Minimal),
      startTimeMode_(StartTimeMode::Left), minDurationMs_(1),
      createdRecords_(0) {}

void DayManager::setMode(SlotSelectionMode mode) { slotSelectionMode_ = mode; }

void DayManager::setMode(StartTimeMode mode) { startTimeMode_ = mode; }

inline QTime DayManager::minDuration() const noexcept {
  return QTime::fromMSecsSinceStartOfDay(minDurationMs_);
}

qsizetype DayManager::createdRecords() const noexcept {
  return createdRecords_;
}

qsizetype DayManager::slotCount() const { return availableSlots_.size(); }

#endif // DAY_MANAGER_H