#include "protocol.h"
#include <string.h>

static uint16_t _check_sum(uint8_t*data,uint16_t size);

/*
 * 调用 protocol_send_xxx 接口的时候，需要注意需要多分配can_head_t 大小的内存，并且
 * 需要offset掉can_head_t 大小, 这样设计的原因是避免多次拷贝
*/
void protocol_send_bms_info(protocol_head_t *head){
	can_head_t *can = (can_head_t *)(((uint8_t *)head) - sizeof(can_head_t));
	can->can_addr = 0x42;
	can->size = head->size;
	can->can_key = 0x00;
	head->checksum = 0;
	head->checksum = _check_sum((uint8_t *)head, head->size);

	//send from uart
}


void protocol_send_debug_info(uint8_t dest, char *data, int size){
	can_head_t *can = (can_head_t *)(((uint8_t *)data) - sizeof(can_head_t));
	can->can_addr = dest;
	can->size = size;
	can->can_key = 0x00;

	//send from uart
}

static uint16_t _check_sum(uint8_t*data,uint16_t size)
{
	uint32_t checksum;
	if((NULL == data)||(0 == size)){
		return 0;
	}
	checksum = 0;
	while(size>1) {
		checksum += *(uint16_t*)data;
		data += 2;
		size -= 2;
	}
	if(size>0) {
		checksum += *data;
	}

	while(checksum>>16) {
		checksum = (checksum&0xFFFF)+(checksum>>16);
	}
	return (uint16_t)~checksum;
}