/*****************************************************************************/
/**
 * @file framing.h
 * @author FanHao (hao_fan_bit_ee@163.com)
 * @brief DF Linklayer framing functions.
 * @version 0.0
 * @date 2023-05-06
 *
 * @copyright Copyright(c) 2024 Beijing Institute of Technology.\n
 * Lab of Communication and Network
 *
 ******************************************************************************/

/**
 * @addtogroup LinkLayer
 * @{
 */

/**
 * @addtogroup LinkLayer_Framing
 * @{
 */
/***************************** Include Files *********************************/
#include <stdint.h>
#include <string.h>
#include "error.h"
#include "common.h"
#include "msg_def.h"
#include "link_layer.h"

/************************** Constant Definitions *****************************/

/*****************************************************************************/
/**
 * @brief   Insert a data chunk to a bit array.
 *
 * @param   frame	pointer to target bit array.
 * @param   offset	offset of insert start position.
 * @param   bytes	number of insert bytes
 * @param   chunk	pointer to data chunk
 *
 * @return	NONE
 *
 ******************************************************************************/
void L2_FrameInsertChunk(uint8_t *frame, size_t offset, size_t bytes, const void *chunk)
{
	ASSERT(frame != NULL);
	ASSERT(chunk != NULL);
	memcpy(frame + offset, chunk, bytes);
}

/*****************************************************************************/
/**
 * @brief   Get a data chunk to a frame buff.
 *
 * @param   frame	pointer to target bit array.
 * @param   offset	offset of data chunk start position.
 * @param   bytes	number of data bytes
 * @param   chunk	pointer to data chunk
 *
 * @return	NONE
 *
 ******************************************************************************/
void L2_FrameGetChunk(uint8_t *frame, size_t offset, size_t bytes, void *chunk)
{
	ASSERT(frame != NULL);
	ASSERT(chunk != NULL);
	memcpy(chunk, frame + offset, bytes);
}

/*****************************************************************************/
/**
 * @brief   Generate crc of specified data.
 *
 * @param   dataBuff	pointer to data buffer.
 * @param   dataLen		length of specified data.
 * @param   crcType		type of crc
 * @param   crc			a pointer to 32 bit crc container.
 *
 * @return	FAILURE	crc type not support.
 * 			SUCCESS
 *
 ******************************************************************************/
int32_t L2_CrcGen(uint8_t *dataBuff, uint32_t dataLen, L2_CRC_TYPE crcType, uint32_t *crc)
{
	ASSERT(dataBuff != NULL);
	int32_t Status;
	switch (crcType)
	{
	case L2_CRC16_1021:
		Status = crc16_gen(dataBuff, dataLen, 0x1021, (uint16_t *)crc);
		break;
	case L2_CRC16_8005:
		Status = crc16_gen(dataBuff, dataLen, 0x8005, (uint16_t *)crc);
		break;
	case L2_CRC8_31:
		Status = crc8_gen(dataBuff, dataLen, 0x31, (uint8_t *)crc);
		break;
	default:
		Status = EPARAM;
		break;
	}
	return Status;
}

/*****************************************************************************/
/**
 * @brief   Append a crc of specified data, to a specified position.
 *
 * @param   dataBuff	pointer to data buffer.
 * @param   dataLen		length of specified data.
 * @param   crcPos		position of crc insert position
 * @param   crcType		type of crc
 *
 * @return	FAILURE	crc type not support.
 * 			SUCCESS
 *
 ******************************************************************************/
int32_t L2_CrcAppend(uint8_t *dataBuff, uint32_t dataLen, uint32_t crcPos, L2_CRC_TYPE crcType)
{
	ASSERT(dataBuff != NULL);
	int32_t Status;
	uint32_t crcVal;
	uint8_t *crcPtr;
	crcPtr = dataBuff + crcPos;
	Status = L2_CrcGen(dataBuff, dataLen, crcType, &crcVal);
	if (Status != SUCCESS)
	{
		return Status;
	}
	switch (crcType)
	{
	case L2_CRC16_1021:
		*(crcPtr + 1) = (uint8_t)(crcVal >> 8);
		*crcPtr = (uint8_t)(crcVal);
		break;
	case L2_CRC16_8005:
		*(crcPtr + 1) = (uint8_t)(crcVal >> 8);
		*crcPtr = (uint8_t)(crcVal);
		break;
	case L2_CRC8_31:
		*crcPtr = (uint8_t)crcVal;
		break;
	default:
		Status = EPARAM;
		break;
	}
	return Status;
}

/*****************************************************************************/
/**
 * @brief   Check data validation by crc.
 *
 * @param   dataBuff	pointer to data buffer.
 * @param   dataLen		length of specified data.
 * @param   crcType		type of crc
 *
 * @return	FAILURE	crc type not support.
 * 			SUCCESS
 *
 ******************************************************************************/
bool L2_CrcCheck(uint8_t *dataBuff, uint32_t dataLen, L2_CRC_TYPE crcType)
{
	ASSERT(dataBuff != NULL);
	int32_t Status;
	uint32_t crcVal;
	crcVal = 0U;
	Status = L2_CrcGen(dataBuff, dataLen, crcType, &crcVal);
	if (Status == SUCCESS)
	{
		if (crcVal == 0)
		{
			return true;
		}
		else
		{
			return false;
		}
	}
	else
	{
		return false;
	}
}

/** @} LinkLayer_Framing*/

/** @} LinkLayer*/