#ifndef FWU_H
#define FWU_H

#include <stdint.h>

/**
 * @file fwu.h
 * @brief API for the Firmware Update (FWU) library.
 *
 * This library provides the core logic for handling the over-the-air firmware
 * update process via Modbus. It manages the data buffer, processes commands,
 * and calculates CRC checksums for data verification.
 */

/**
 * @brief Initializes the firmware update module.
 *
 * This function currently does nothing but is a placeholder for future
 * initialization logic.
 */
void fwu_init(void);

/**
 * @brief Handles incoming Modbus register writes related to firmware updates.
 *
 * This function is the main entry point for the FWU process. It parses the
 * address and value from a Modbus write operation and takes appropriate action,
 * such as storing metadata (offset, size) or data chunks, and processing
 * commands (verify, finalize).
 *
 * @param addr The Modbus register address being written to.
 * @param reg The 16-bit value being written to the register.
 */
void fwu_handler(uint16_t addr, uint16_t reg);

/**
 * @brief Gets the CRC16-CCITT of the last received firmware chunk.
 *
 * After a data chunk is fully received into the buffer, this function can be
 * called to retrieve the calculated CRC checksum. The master can then compare
 * this with its own calculated CRC to verify data integrity.
 *
 * @return The 16-bit CRC of the last chunk.
 */
uint16_t fwu_get_last_chunk_crc(void);

#endif // FWU_H