#ifndef TMTCPACKET_PUS_TCPACKETBASE_H_
#define TMTCPACKET_PUS_TCPACKETBASE_H_

#include <fsfw/tmtcpacket/RedirectableDataPointerIF.h>

#include <cstddef>

#include "fsfw/tmtcpacket/SpacePacketBase.h"

/**
 * This class is the basic data handler for any ECSS PUS Telecommand packet.
 *
 * In addition to #SpacePacketBase, the class provides methods to handle
 * the standardized entries of the PUS TC Packet Data Field Header.
 * It does not contain the packet data itself but a pointer to the
 * data must be set on instantiation. An invalid pointer may cause
 * damage, as no getter method checks data validity. Anyway, a NULL
 * check can be performed by making use of the getWholeData method.
 * @ingroup tmtcpackets
 */
class TcPacketPusBase : public SpacePacketBase, virtual public RedirectableDataPointerIF {
  friend class TcPacketStoredBase;

 public:
  enum AckField : uint8_t {
    //! 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,
    //! Acknowledfgement on completion are expected.
    ACK_COMPLETION = 0b1000
  };

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

  /**
   * This is the default constructor.
   * It sets its internal data pointer to the address passed and also
   * forwards the data pointer to the parent SpacePacketBase class.
   * @param setData	The position where the packet data lies.
   */
  TcPacketPusBase(const uint8_t* setData);
  /**
   * This is the empty default destructor.
   */
  virtual ~TcPacketPusBase();

  /**
   * This command returns the CCSDS Secondary Header Flag.
   * It shall always be zero for PUS Packets. This is the
   * highest bit of the first byte of the Data Field Header.
   * @return	the CCSDS Secondary Header Flag
   */
  virtual uint8_t getSecondaryHeaderFlag() const = 0;
  /**
   * 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
   */
  virtual uint8_t getPusVersionNumber() 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.
   */
  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.
   */
  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.
   */
  virtual uint8_t getSubService() const = 0;
  /**
   * The source ID can be used to have an additional identifier, e.g. for different ground
   * station.
   * @return
   */
  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.
   */
  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)
   */
  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
   */
  virtual uint16_t getErrorControl() const = 0;
  /**
   * With this method, the Error Control Field is updated to match the
   * current content of the packet.
   */
  virtual void setErrorControl() = 0;

  /**
   * Calculate full packet length from application data length.
   * @param appDataLen
   * @return
   */
  virtual size_t calculateFullPacketLength(size_t appDataLen) const = 0;

  /**
   * This is a debugging helper method that prints the whole packet content
   * to the screen.
   */
  void print();

 protected:
  /**
   * With this method, the packet data pointer can be redirected to another
   * location.
   * This call overwrites the parent's setData method to set both its
   * @c tc_data pointer and the parent's @c data pointer.
   *
   * @param p_data    A pointer to another PUS Telecommand Packet.
   */
  virtual ReturnValue_t setData(uint8_t* pData, size_t maxSize, void* args = nullptr) override = 0;
};

#endif /* TMTCPACKET_PUS_TCPACKETBASE_H_ */