/**
  * @RDE_HEADER@
  * RtState
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by Christian Fröbel, NLE, 2018-12-16
  */

#pragma once

#include "avm_export.h"
#include "ava_types.h"
#include <AudioVideoManagement/avm_enums.hpp>
#include <boost/optional.hpp>
#include <vector>
#include <map>
#include <string>
#include <cstdint>

namespace AudioVideoManagement
{

/**
 * RtState is part of AvaState. It mirrors the state of AVS_Workstation related
 * to the radio circuits.
 * It has two perspectives or users:
 * 1. AvaState itself. As AvaState observes the back-channel of the communication with AVS_Workstation,
 *    it takes note of all changes in state notified by AVS_Workstation.
 *    The observed state changes are:
 *    - the currently selected sum channel
 *    - the volume for each radio circuit
 *    - the currently selected radio circuit (for each position)
 *    - the current state of the buttons (for each position)
 * 2. RtProfileObserver. It observes changes in the user's profile and also changes of the names of
 *    the radio circuits. It then issues commands via AvaControl which in turn determine the
 *    wanted target state which is then sent to AVS_Workstation.
 *    A target state is determined by copying the current state and then modify it by calling
 *    setRadioCircuits() or changeName().
 *
 * @see AvaState
 * @see RtProfileObserver
 * @see SetRtProfile
 * @see ChangeRtProfileCircuitName
 *
 * @author Christian Fröbel
 */
class AVM_COMMON_EXPORT RtState
{
public:
  struct RadioCircuit
  {
    RadioSystem   radioSystem;
    int32_t       id;
    std::string   name;
  };

  /**
   * Initially set the radio circuits accessible by the user in AVS_Workstation.
   * Is also called whenever the profile is changed by the user.
   * In case the new radio circuit is already known, the state is kept (volume setting and button state).
   * The order in the vector corresponds to the position in AVS_Workstation.
   */
  void setRadioCircuits(const QVector<RadioCircuit> &radioCircuits);
  void changeName(const RadioCircuit &radioCircuit);
  void setSumChannel(AvaSumChannel sumChannel);

  /** Empty name means de-selection. */
  void setSelection(AvaRtPos pos, const std::string &name, AvaRtButtonState s);
  void setVolume(const std::string &name, AvaVolume volume);

  /**
   * Return the command representing the current state.
   * The command is a valid RCP_AVA command (setRtProfile).
   */
  std::string toCommand() const;

  AvaSumChannel sumChannel() const { return m_sumChannel; }
  std::vector<std::string> allRadioCircuits() const;

  /**
   * Returns the radio circuits currently selected in AVS_Workstation.
   * Thus the size of the returned vector is always <= 8.
   * The order in the vector corresponds to the order of ComboBoxes (from top-left to bottom-right).
   */
  std::vector<std::string> selectedRadioCircuits() const;

private:
  /**
   * We store a radio circuit under such a key in order to identify
   * the radio circuit.
   */
  struct Key
  {
    static Key createFrom(const RadioCircuit &radioCircuit);

    RadioSystem   radioSystem;
    int32_t       id;

    bool operator==(const Key &other) const;
    bool operator!=(const Key &other) const { return !(*this == other); }
    bool operator<(const Key &other) const;
  };

  struct CircuitState
  {
    explicit CircuitState(const std::string &name_);

    std::string   name;
    AvaVolume     volume{0};

    std::string toCommandPart() const;
  };

  struct PosState
  {
    PosState() = default;
    explicit PosState(const Key &key_, AvaRtButtonState s = AvaRtButtonState::None);

    boost::optional<Key>   key;
    AvaRtButtonState       buttonState{AvaRtButtonState::None};

    std::string toCommandSelectionPart(const std::map<Key, CircuitState> &radioCircuits) const;
    std::string toCommandStatePart() const;
  };

  std::map<Key, CircuitState>::iterator findRadioCircuit(const std::string &name);

  std::map<Key, CircuitState>               m_radioCircuits;
  std::array<PosState, AvaRtPos::count()>   m_states;
  AvaSumChannel                             m_sumChannel{AvaSumChannel::Right};
};

} // namespace AudioVideoManagement