/***************************************************************************************
* \copyright:    2020-2022 Thales Alenia Space Deutschland GmbH
* \project:      multiMIND
* \file:         crc.c
* \date:         22.02.2022
* \author:       David Woodward
* \brief:        CRC algorithms
***************************************************************************************/

#ifndef TAS_D_C_CRC_H
#define TAS_D_C_CRC_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stdint.h>
#include <stdbool.h>

// NOTE: These defines are in the header as some are needed for (initial) crc function calls
//CRC-32/BZIP2
#define CRC32_TOPBIT (1UL<<31)
#define CRC32_POLYNOMIAL 0x04C11DB7
#define CRC32_INITIAL_REMAINDER 0xFFFFFFFF
#define CRC32_FINAL_XOR_VALUE	0xFFFFFFFF

// CRC-16/CCITT-FALSE
#define CRC16_INITIAL_REMAINDER 0xFFFF
#define CRC16_FINAL_XOR_VALUE 0x0

extern const uint16_t crc16_0x1021_table[256];

extern const uint16_t crc16_0x1021_table_reverse[256];

/**
 * \brief CRC-32/BZIP2 algorithm
 */
uint32_t Crc32(const uint8_t *msg, int numBytes, uint32_t remainder);


/**
 * \brief CRC-16/CCITT-FALSE (alias CRC-16/AUTOSAR) algorithm,
// initial: 0xFFFF, xorOut: 0x0000, RefIn: false, RefOut: false, polynomial: 0x1021
 * using a lookup table
 * \param data Data
 * \param len Data length
 * \param remainder Remainder to be used,
 * use initial remainder for non coherent/standalone calculations
 * \param final_xor The value that the final result will be xored
 * \return CRC result
 */
uint16_t calc_crc16_unreflected(const uint8_t *data, uint32_t len, uint16_t remainder, uint16_t final_xor);

/**
 * generates a 16-bit CRC for the said data
 *
 * @param data input data for CRC
 * @param len length of the data
 * @return crc Generated 16-bit CRC
 */
void calc_crc16_byte_unreflected(uint16_t *crc16, uint8_t bt);

/**
 * \brief CRC-16/CCITT-FALSE (alias CRC-16/AUTOSAR) algorithm,
 * polynomial: 0x1021, initial: 0xFFFF, final xor: 0x0,
 * using a lookup table
 * \param data Data
 * \param len Data length
 * \param remainder Remainder to be used,
 * use initial remainder for non coherent/standalone calculations
 * \param final_xor The value that the final result will be xored
 * \return CRC result
 */
uint16_t calc_crc16_buff_unreflected(uint8_t *data, uint16_t len);

/**
 * \brief CRC-16/X25 algorithm,
 * initial: 0xFFFF, xorOut: 0xFFFF, RefIn: true, RefOut: true, polynomial: 0x1021
 * using a lookup table
 * \param data Data
 * \param len Data length
 * \param remainder Remainder to be used,
 * use initial remainder for non coherent/standalone calculations
 * \param final_xor The value that the final result will be xored
 * \return CRC result
 */
uint16_t calc_crc16_reflected(const uint8_t *data, uint32_t len, uint16_t remainder, uint16_t final_xor);

/**
 * \brief CRC-16/X25 algorithm,
 * calculates the crc16 for the next byte, given an already calculated crc16
 *
 * @param *crc16 : calculated crc16 - the value will be updated
 * @param bt : next byte for crc16 calculation
 * @return none
 */
void calc_crc16_byte_reflected(uint16_t *crc16, uint8_t bt);

/**
 * \brief CRC-16/X25 algorithm,
 * initial: 0xFFFF, xorOut: 0xFFFF, RefIn: true, RefOut: true, polynomial: 0x1021
 * using a lookup table
 * \param data Data
 * \param len Data length
 * \param remainder Remainder to be used,
 * use initial remainder for non coherent/standalone calculations
 * \param final_xor The value that the final result will be xored
 * \return CRC result
 */
uint16_t calc_crc16_buff_reflected(const uint8_t *data, uint16_t len);

#ifdef __cplusplus
}
#endif

#endif