/**
  * @RDE_HEADER@
  * ExerciseContext
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by Christian Fröbel, SLSE, 2017-11-22
  */

#pragma once

#include "avm_export.h"
#include <boost/optional.hpp>
#include <QtGlobal>
#include <ostream>

class QString;
class QByteArray;

namespace AudioVideoManagement
{

/**
 * Small value class in order to handle the exercise context (string) used in AVS.
 * Such a context is associated with an exercise ID used by our system.
 * But AVS also has the notion of a default context named "default"
 * which has no associated ID on our side.
 *
 * @author Christian Fröbel
 */
class AVM_COMMON_EXPORT ExerciseContext
{
public:
  explicit ExerciseContext(int exerciseId)
    : m_exerciseId(exerciseId)
  {
    //Q_ASSERT(exerciseId > 0);
  }

  static ExerciseContext defaultContext() { return ExerciseContext(); }

  static ExerciseContext fromByteArray(const QByteArray &s);
  static ExerciseContext fromString(const QString &s);

  bool isDefault() const { return !m_exerciseId.is_initialized(); }

  /** May only be called if this is not the "default" context. */
  int id() const { return *m_exerciseId; }

  QString toString() const;
  QByteArray toByteArray() const;

  bool operator==(const ExerciseContext &other) const { return m_exerciseId == other.m_exerciseId; }
  bool operator!=(const ExerciseContext &other) const { return !(*this == other); }

  bool operator<(const ExerciseContext &other) const;

private:
  /** Create the "default" AVS context. */
  ExerciseContext() = default;

  boost::optional<int>   m_exerciseId; //!< not set for "default" context
};

AVM_COMMON_EXPORT std::ostream &operator<<(std::ostream &os, const ExerciseContext &ctx);

} // namespace AudioVideoManagement