nBus-bridge/Core/Inc/NbusBridge.h

/**
 * @file NbusBridge.h
 * @brief Declaration of nBus Bridge
 * @date Nov 27, 2025
 * @author Juraj Dudak, Matus Necas
 */

#ifndef SRC_NBUSBRIDGE_H_
#define SRC_NBUSBRIDGE_H_

#include "NbusSlave.h"

/**
 * Class representing nBus Bridge.
 */
class NbusBridge
{
public:

	/** Constructor
	 * @param nbus_communicator: hardware communicator.
	 */
	NbusBridge(NbusCommunicator *nbus_communicator);

	/** Provide scan of internal nBus net and initialize local slave devices data.
	 */
	void scanNetwork();

	/** Process incoming requests.
	 * @param rx_frame: RX data packet
	 * @param size: size of rx_frame
	 */
	void processRequest(uint8_t *rxFrame, uint8_t size);

	/**
	 * Implementation of the STATE_RUNNING state.
	 * In this state, automatic reading of data from all slaves/all sensors is running.
	 * The data is sent to the Master in a batch (for all slaves).
	 */
	void processRunningState();

private:
	/** Get slave pointer.
	 * @param index: slave id
	 * @return pointer to slave
	 * @note: can be nullptr
	 */
	NbusSlave* _getSlave(uint8_t index);

	/** Calculate 8-bit CRC.
	 *  @param mem: data buffer
	 *  @param len: buffer length
	 *  @return> crc
	 */
	uint8_t _crc8x_fast(void const *mem, uint16_t len);

	/** Process broadcast request.
	 * @param rx_frame: RX data packet
	 * @param size: size of rx_frame
	 */
	void _processBroadcast(uint8_t *rx_frame, uint8_t size);

	/** Process bridge request (e.g. bridge-cast).
	 * @param rx_frame: RX data packet
	 * @param size: size of rx_frame
	 */
	void _processBridgeRequest(uint8_t *rxFrame, uint8_t size);

	/** Process slave request (e.g. uni-cast).
	 * @param rx_frame: RX data packet
	 * @param size: size of rx_frame
	 */
	void _processSlaveRequest(uint8_t *rxFrame, uint8_t size);

	/** Implementation of CMD_GET_DATA for bridge.
	 * @return: response to master
	 */
	DataFrame * _cmdGetData();

	/** Implementation of CMD_GET_INFO for bridge.
	 * @return: response to master
	 */
	DataFrame * _cmdGetInfo();

	/** Implementation of CMD_GET_FORMAT for bridge.
	 * @return: response to master
	 */
	DataFrame * _cmdGetFormat();

	/** Implementation of CMD_GET_SLAVES for bridge.
	 * @return: response to master
	 */
	DataFrame * _cmdGetSlaves();

	/** Implementation of CMD_SET_STOPfor bridge.
	 */
	void _cmdSetStop();

	/** Implementation of CMD_SET_START for bridge.
	 */
	void _cmdSetStart();

	/** Set error response to master.
	 * @param error_code: error code
	 * @return: response to master
	 */
	DataFrame * _rspSetError(Nbus_EC_e error_code);

	/** Set status response to master.
	 * @param error_code: error code
	 * @return: response to master
	 */
	DataFrame * _rspSetStatus(Nbus_SC_e status_code);

	/** Make default packet from pdu and data.
	 * @param pdu: current pdu
	 * @param data: application data
	 * @param size: application data size
	 * @return: response to master
	 */
	DataFrame * _makePacket(Nbus_PDU_t pdu, uint8_t *data, uint8_t size);

	DataFrame * _makeBridgeDataPacket();

	/** Make raw packet (just copy whole input frame).
	 * @param daa: application data
	 * @param size: application data size
	 * @return: response to master
	 */
	DataFrame * _forwardPacket(uint8_t *data, uint8_t size);

	void _addDataPayload(DataFrame * data_frame);




	NbusCommunicator *_communicator{nullptr};													///< nBus HW communicator
	NbusSlave _slaves[NBUS_BRIDGE_MAX_SLAVES];                                                  ///< array of nBus slaves
	uint8_t _slave_adress[NBUS_BRIDGE_MAX_SLAVES]{0};                                           ///< array of slave addresses
	uint8_t _num_slaves{0};                                                                     ///< number of slaves
	Nbus_RunState_e _run_state{STATE_STOPPED};                                                  ///< running state flag
	DataFrame *_worker_frame_ptr{nullptr};														///< pointer to actual data frame
	uint8_t _data_packet[NBUS_BRIDGE_DATAPACKET_SIZE]{0};                                       ///< data packet buffer
	DataFrame _bridge_cast_frame{_data_packet, NBUS_BRIDGE_DATAPACKET_SIZE, TYPE_RAW, CRC_OFF}; ///< data frame for bridge cast
	DataFrame _default_frame{_data_packet, NBUS_BRIDGE_DATAPACKET_SIZE, TYPE_PLAIN, CRC_ON};    ///< data frame for default operation
	DataFrame _raw_data_frame{_data_packet, NBUS_BRIDGE_DATAPACKET_SIZE, TYPE_RAW, CRC_OFF};    ///< raw data frame for copying
	uint8_t _scan_request{0};																	///< flag if scan request is necessary
	Nbus_PDU_t _pdu{NBUS_BROADCAST_ADDRESS, NBUS_BROADCAST_ADDRESS, FC_ECHO};                   ///< nBus actual PDU
	uint8_t _bridge_cast_header[NBUS_BRIDGE_HEADER_SIZE]{NBUS_BRIDGE_HEADER_SEQ};               ///< data header for bridge-cast
};

#endif /* SRC_NBUSBRIDGE_H_ */