/**
 * TODO file description
 *
 * Created on 2022/01/02.
 */

#ifndef ESPNODE_MODBUS_FN_H
#define ESPNODE_MODBUS_FN_H

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

/**
 * Build "read holding registers" packet
 *
 * @param buf buf to write to
 * @param len buf len
 * @param resplen expected response length (if not exception)
 * @param mbAddr mb address
 * @param ref first register number
 * @param qty register quantity
 * @return number of buf bytes if success, negative if error
 */
int mb_build_fc3(uint8_t *buf, size_t len, size_t *resplen, uint8_t mbAddr, uint16_t ref, uint16_t qty);

/**
 * Parse "read holding registers" response
 *
 * @param buf buf with the response bytes
 * @param len response buf len
 * @param dst store results here
 * @param capacity capacity of "dst"
 * @return num of results, negative if error
 */
int mb_parse_fc3(const uint8_t *buf, size_t len, uint16_t *dst, size_t capacity);

/**
 * Build "read input registers" packet
 *
 * @param buf buf to write to
 * @param len buf len
 * @param resplen expected response length (if not exception)
 * @param mbAddr mb address
 * @param ref first register number
 * @param qty register quantity
 * @return number of buf bytes if success, negative if error
 */
int mb_build_fc4(uint8_t *buf, size_t len, size_t *resplen, uint8_t mbAddr, uint16_t ref, uint16_t qty);

/**
 * Parse "read input registers" response
 *
 * @param buf buf with the response bytes
 * @param len response buf len
 * @param dst store results here
 * @param capacity capacity of "dst"
 * @return num of results, negative if error
 */
int mb_parse_fc4(const uint8_t *buf, size_t len, uint16_t *dst, size_t capacity);

/**
 * Build "write holding registers" packet
 *
 * @param buf buf to write to
 * @param len buf len
 * @param resplen expected response length (if not exception)
 * @param mbAddr mb address
 * @param ref first register number
 * @param data register data to write, as an array
 * @param qty register quantity
 * @return number of buf bytes if success, negative if error
 */
int mb_build_fc16(uint8_t *buf, size_t len, size_t *resplen, uint8_t mbAddr, uint16_t ref, const uint16_t *data, uint16_t qty);

/**
 * Parse "write holding registers" response
 *
 * @param buf buf with the response bytes
 * @param len response buf len
 * @return 0 if success, negative if error
 */
bool mb_parse_fc16(const uint8_t *buf, size_t len);

#endif //ESPNODE_MODBUS_FN_H