/* modbus 从机实现*/

#include<stdint.h>
#include "crc.h"
#include "modbus-s.h"

#if !defined(LOG_TAG)
    #define LOG_TAG          "main"
#endif
#include <elog.h>


void ModbusSlaveInit(ModBusSlave_t * drv,uint8_t ID,uint8_t * data,uint16_t  * reg,uint16_t max)
{
	drv->ID = ID;
	drv->data = data ;
	drv->reg = reg;
	drv->regmax = max;
}

// 解析modbus 数据
//-1 地址错误
int ModbusSlaveHandle(ModBusSlave_t * drv,uint8_t * data,uint16_t length )
{
	uint16_t rcrc = 0,ccrc = 0 ;
	if( (data[0] != drv->ID)  && (data[0] != 0x00))
	{
		// 地址错误
		return -1;
	}
	rcrc = ((uint16_t)data[length- 1] << 8) + (uint16_t)data[length- 2] ;
	ccrc = MX_CRC_CALC(data,length-2);
	if (rcrc != ccrc )
	{
		log_e("rcrc:%04X,ccrc:%04X\r\n",rcrc,ccrc) ;
		return -2;
	}
	drv->func = data[1] ;
	
	switch (drv->func)
	{
		case 0x03 :// 读取保持寄存器地址
		{
			drv->Addr   = ((uint16_t)data[2] << 8) + data[3];
			drv->length = ((uint16_t)data[4] << 8) + data[5];
			break;
		}
		case 0x04:
			break;
		case 0x06:  // 写入单个保持寄存器
			drv->Addr   = ((uint16_t)data[2] << 8) + data[3];
			drv->data[0] = data[4];
			drv->data[1] = data[5];
			break;
		default:
			return -3 ;
			break;
	}
	return 0;
	// if() // 寄存器最大值
}
// 从机数据应答
int ModbusSlavePacket(ModBusSlave_t * drv,uint8_t *data)
{
	int tx_size = 0;
	uint16_t crc = 0;
	data[tx_size++] = drv->ID;
	data[tx_size++] = drv->func;
	char * p = (char *)&drv->reg[drv->Addr];
	switch (drv->func)
	{
		case 0x03:
			data[tx_size++] = drv->length *2;
			for(int i =0;i < drv->length *2;i++)
			{
				data[tx_size++] = *p;
				p++;
			}
			break;
		case 0x06: //
			data[tx_size++] = (drv->Addr >> 8) & 0x00FF;
			data[tx_size++] = drv->Addr & 0x00FF;
			data[tx_size++] = drv->data[0];
			data[tx_size++] = drv->data[1];
			break;
		default :
			break;
	}
	crc = MX_CRC_CALC(data,tx_size);
	data[tx_size++] =  crc & 0x00FF;
	data[tx_size++] = (crc >> 8) & 0x00FF;
	return tx_size;
}

//// 读取保持寄存器的值
//// addr  寄存器地址
//// id 丛机地址
//// length 读取丛机数据长度
//int modbus_m_read_regist(uint8_t id,uint16_t addr,uint16_t length,uint8_t * data)
//{
//	uint16_t index = 0,crc;
//	data[index++] = id;
//	data[index++] = 0x03;
//	data[index++] = (addr >> 8) & 0x00FF;
//	data[index++] = addr & 0x00FF;
//	data[index++] = (length >> 8) & 0x00FF;
//	data[index++] = length & 0x00FF;
//	crc = MX_CRC_CALC(data,index);
//	data[index++] =  crc & 0x00FF;
//	data[index++] = (crc >> 8) & 0x00FF;
//	return index;
//}

//// 解析通过03 命令读取回来额寄存器数据
//int modbus_m_read_regist_ack(uint)
//{
//	
//}