/*
 * @file utils.cpp
 * @brief Utility functions implementation
 *
 * Created: 21.09.2025
 * Author: ThePetrovich
 *
 * Copyright YKSA - Sakha Aerospace Systems, LLC.
 * See the LICENSE file for details.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include "utils.h"
#include "config.h"
#include <Arduino.h>

uint16_t calculate_crc16_xmodem(uint8_t *data, uint16_t len)
{
	uint16_t crc = 0;
	uint8_t i;

	while (len--) {
		crc ^= (uint16_t)(*data++) << 8;
		for (i = 0; i < 8; i++) {
			if (crc & 0x8000) {
				crc = (crc << 1) ^ 0x1021;
			} else {
				crc <<= 1;
			}
		}
	}

	return crc;
}

int16_t adc_to_temperature_c(uint16_t adc_value)
{
	// MCP9700: 500 mV at 0°C, 10 mV per degree, vref = 3.0V
	// Result in 0.1°C units
	return (int16_t)((adc_value * ADC_VREF_MV / ADC_RESOLUTION - TEMP_SENSOR_OFFSET_MV));
}

uint16_t adc_to_voltage_mv(uint16_t adc_value) { return (uint16_t)(adc_value * VOLTAGE_MV_PER_STEP); }

uint16_t read_adc_oversampled(uint8_t pin, uint8_t samples)
{
	uint32_t sum = 0;

	uint8_t shift = ((samples == 64) ? 3 : (samples == 16) ? 2 : (samples == 4) ? 1 : 0);

	for (uint8_t i = 0; i < samples; i++) {
		sum += analogRead(pin);
	}

	return (uint16_t)(sum >> shift);
}