#ifndef FSFW_TMTCPACKET_PUSTCIF_H
#define FSFW_TMTCPACKET_PUSTCIF_H

#include <cstdint>

#include "TcPacketPus.h"

namespace ecss {

enum AckField {
  //! No acknowledgements are expected.
  ACK_NONE = 0b0000,
  //! Acknowledgements on acceptance are expected.
  ACK_ACCEPTANCE = 0b0001,
  //! Acknowledgements on start are expected.
  ACK_START = 0b0010,
  //! Acknowledgements on step are expected.
  ACK_STEP = 0b0100,
  //! Acknowledgement on completion are expected.
  ACK_COMPLETION = 0b1000
};

static constexpr uint8_t ACK_ALL = ACK_ACCEPTANCE | ACK_START | ACK_STEP | ACK_COMPLETION;

/**
 * This struct defines a byte-wise structured PUS C ata Field Header.
 * Any optional fields in the header must be added or removed here.
 * Currently, the Source Id field is present with one byte.
 * No spare byte support for now.
 * @ingroup tmtcpackets
 */
struct PusTcDataFieldHeader {
  // Version and ACK byte, Service Byte, Subservice Byte, 2 byte Source ID
  static constexpr size_t MIN_LEN = 5;
  uint8_t pusVersion;
  uint8_t ackFlags;
  uint8_t serviceType;
  uint8_t serviceSubtype;
  uint16_t sourceId;
};

}  // namespace ecss

class PusTcIF : public SpacePacketIF {
 public:
  ~PusTcIF() override = default;
  static const uint16_t MIN_LEN =
      (sizeof(CCSDSPrimaryHeader) + ecss::PusTcDataFieldHeader::MIN_LEN + 2);

  /**
   * This command returns the TC Packet PUS Version Number.
   * The version number of ECSS PUS 2003 is 1.
   * It consists of the second to fourth highest bits of the
   * first byte.
   * @return
   */
  [[nodiscard]] virtual uint8_t getPusVersion() const = 0;
  /**
   * This is a getter for the packet's Ack field, which are the lowest four
   * bits of the first byte of the Data Field Header.
   *
   * It is packed in a uint8_t variable.
   * @return	The packet's PUS Ack field.
   */
  [[nodiscard]] virtual uint8_t getAcknowledgeFlags() const = 0;
  /**
   * This is a getter for the packet's PUS Service ID, which is the second
   * byte of the Data Field Header.
   * @return	The packet's PUS Service ID.
   */
  [[nodiscard]] virtual uint8_t getService() const = 0;
  /**
   * This is a getter for the packet's PUS Service Subtype, which is the
   * third byte of the Data Field Header.
   * @return	The packet's PUS Service Subtype.
   */
  [[nodiscard]] virtual uint8_t getSubService() const = 0;
  /**
   * The source ID can be used to have an additional identifier, e.g. for different ground
   * station.
   * @return
   */
  [[nodiscard]] virtual uint16_t getSourceId() const = 0;

  /**
   * This is a getter for a pointer to the packet's Application data.
   *
   * These are the bytes that follow after the Data Field Header. They form
   * the packet's application data.
   * @return	A pointer to the PUS Application Data.
   */
  [[nodiscard]] virtual const uint8_t* getApplicationData() const = 0;
  /**
   * This method calculates the size of the PUS Application data field.
   *
   * It takes the information stored in the CCSDS Packet Data Length field
   * and subtracts the Data Field Header size and the CRC size.
   * @return	The size of the PUS Application Data (without Error Control
   * 		field)
   */
  [[nodiscard]] virtual uint16_t getApplicationDataSize() const = 0;
  /**
   * This getter returns the Error Control Field of the packet.
   *
   * The field is placed after any possible Application Data. If no
   * Application Data is present there's still an Error Control field. It is
   * supposed to be a 16bit-CRC.
   * @return	The PUS Error Control
   */
  [[nodiscard]] virtual uint16_t getErrorControl() const = 0;
};
#endif  // FSFW_TMTCPACKET_PUSTCIF_H