fsfw/tmtcpacket/pus/TcPacketBase.h

#ifndef TMTCPACKET_PUS_TCPACKETBASE_H_
#define TMTCPACKET_PUS_TCPACKETBASE_H_

#include "../../tmtcpacket/SpacePacketBase.h"
#include <cstddef>

/**
 * 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 TcPacketBase : public SpacePacketBase {
    friend class TcPacketStoredBase;
public:

	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,
		//! 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.
	 */
	TcPacketBase( const uint8_t* setData );
	/**
	 * This is the empty default destructor.
	 */
	virtual ~TcPacketBase();

	/**
	 * 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() = 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() = 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() = 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() = 0;
	/**
	 * The source ID can be used to have an additional identifier, e.g. for different ground
	 * station.
	 * @return
	 */
	uint8_t getSourceId();

	/**
	 * 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() = 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() = 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) = 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.
     */
    void setData( const uint8_t* pData ) = 0;
};


#endif /* TMTCPACKET_PUS_TCPACKETBASE_H_ */