eive-obsw/bsp_q7s/devices/startracker/ArcsecDatalinkLayer.h

#ifndef BSP_Q7S_DEVICES_ARCSECDATALINKLAYER_H_
#define BSP_Q7S_DEVICES_ARCSECDATALINKLAYER_H_

#include "StarTrackerDefinitions.h"
#include "fsfw/returnvalues/HasReturnValuesIF.h"

extern "C" {
    #include "common/misc.h"
}

/**
 * @brief   Helper class to handle the datalinklayer of replies from the star tracker of arcsec.
 */
class ArcsecDatalinkLayer: public HasReturnvaluesIF {
public:

    static const uint8_t INTERFACE_ID = CLASS_ID::STR_HANDLER;

    //! [EXPORT] : [COMMENT] More data required to complete frame
    static const ReturnValue_t DEC_IN_PROGRESS = MAKE_RETURN_CODE(0xA0);
    //! [EXPORT] : [COMMENT] Data too short to represent a valid frame
    static const ReturnValue_t REPLY_TOO_SHORT = MAKE_RETURN_CODE(0xA1);
    //! [EXPORT] : [COMMENT] Detected CRC failure in received frame
    static const ReturnValue_t CRC_FAILURE = MAKE_RETURN_CODE(0xA2);

    static const uint8_t STATUS_OK = 0;

    ArcsecDatalinkLayer();
    virtual ~ArcsecDatalinkLayer();

    /**
     * @brief   Applies decoding to data referenced by rawData pointer
     *
     * @param rawData          Pointer to raw data received from star tracker
     * @param rawDataSize      Size of raw data stream
     * @param remainingBytes   Number of bytes left
     */
    ReturnValue_t decodeFrame(const uint8_t* rawData, size_t rawDataSize, size_t* bytesLeft);

    /**
     * @brief   SLIP encodes data pointed to by data pointer.
     *
     * @param data   Pointer to data to encode
     * @param length Length of buffer to encode
     */
    void encodeFrame(const uint8_t* data, uint32_t length);

    /**
     * @brief    Returns the frame type field of a decoded frame.
     */
    uint8_t getReplyFrameType();

    /**
     * @brief   Returns pointer to reply packet (first entry normally action ID, telemetry ID etc.)
     */
    const uint8_t* getReply();

    /**
     * @brief   Returns size of encoded frame
     */
    uint32_t getEncodedLength();

    /**
     * @brief   Returns pointer to encoded frame
     */
    uint8_t* getEncodedFrame();

    /**
     * @brief   Returns status of reply
     */
    uint8_t getStatusField();

    /**
     * @brief   Returns ID of reply
     */
    uint8_t getId();

private:

    static const uint8_t ID_OFFSET = 1;
    static const uint8_t STATUS_OFFSET = 2;

    // Used by arcsec slip decoding function process received data
    uint8_t rxBuffer[StarTracker::MAX_FRAME_SIZE];
    // Decoded frame will be copied to this buffer
    uint8_t decodedFrame[StarTracker::MAX_FRAME_SIZE];
    // Buffer where encoded frames will be stored. First byte of encoded frame represents type of
    // reply
    uint8_t encBuffer[StarTracker::MAX_FRAME_SIZE * 2 + 2];
    // Size of decoded frame
    uint32_t decFrameSize = 0;
    // Size of encoded frame
    uint32_t encFrameSize = 0;

    slip_decode_state slipInfo;

    void slipInit();
};

#endif /* BSP_Q7S_DEVICES_ARCSECDATALINKLAYER_H_ */