/*
 * @file config.h
 * @brief System configuration and constants
 *
 * Created: 21.09.2025
 * Author: ThePetrovich
 *
 * Copyright YKSA - Sakha Aerospace Systems, LLC.
 * See the LICENSE file for details.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#ifndef CONFIG_H
#define CONFIG_H

// Firmware version
#define FIRMWARE_VERSION_MAJOR 2
#define FIRMWARE_VERSION_MINOR 03

// Serial communication
#define SERIAL_BAUD_RATE 38400

// Timing constants
#define STATUS_LED_BLINK_PERIOD 500U
#define MAIN_LOOP_DELAY 10
#define CPM_UPDATE_PERIOD 10000U

#define RSENSE_CHANNEL_16_MASK 0x7FFU // 11-bit channel mask
#define RSENSE_CHANNEL_32_MASK 0x3FFU // 10-bit channel mask
#define RSENSE_CHANNEL_COUNT 2048
#define RSENSE_CHANNEL_32_COUNT 1024

// Temperature sensor constants (MCP9700)
#define MCP9700_OFFSET_MV 500L	// 500 mV at 0°C
#define MCP9700_SCALE_MV 10L	// 10 mV per degree
#define ADC_OVERSAMPLING_BITS 2 // 16x oversampling -> 2 extra bits
#define ADC_VREF_MV 3000L	// 3.0V reference
#define ADC_RESOLUTION 1024L	// 10-bit ADC

// Voltage divider constants
#define VOLTAGE_DIVIDER_RATIO 20.0f	// 200k and 10k resistors
#define VOLTAGE_MV_PER_STEP 14.6484375f // (3.0 * 20) / 4096

// EEPROM addresses for potentiometer settings
#define EEPROM_POT_HV_ADDR 0
#define EEPROM_POT_AMP_ADDR 1
#define EEPROM_POT_DET_ADDR 2
#define EEPROM_MAGIC_ADDR 3
#define EEPROM_MAGIC_VALUE 0xA5 // Magic value to check if EEPROM is initialized

// Default potentiometer values
#define DEFAULT_POT_VALUE 127

// Light sensor constants
#define LSENSE_I2C_BASE_ADDR 0x38
#define LSENSE_EXPECTED_ID 0xE0
#define LSENSE_DATA_SIZE 12

typedef struct config_t {
	uint8_t magic1; // 0xA5 to indicate valid config
	uint8_t magic2; // 0x5A to indicate valid config
	uint8_t pot_hv;
	uint8_t pot_amp;
	uint8_t pot_det;
	struct {
		uint16_t adccal0; // ADC offset at GND
		uint16_t adccal3; // ADC reading at 3.0V reference
		uint16_t tempcal;
		uint16_t tempdrift_mvK; // SiPM temperature drift compensation in mV/K, normally around 20 mV/K
		float gainlow; // gain value for pot_amp = 0
		float gainhigh; // gain value for pot_amp = 255
	} calibration __attribute__((packed));
	union {
		struct {
			uint8_t spectrum_oversample_bits
			    : 2; // 0, 1, 2, or 3 for 1x, 4x, 16x, or 64x oversampling, only for spectrum measurement
			uint8_t spectrum_channel_bits : 1; // 0 for 16-bit channels, 1 for 32-bit channels
			uint8_t temperature_drift_compensation
			    : 1;			 // 0 to disable, 1 to enable temperature compensation
			uint8_t adc_oversample_bits : 2; // 0, 1, 2, or 3 for 1x, 4x, 16x, or 64x ADC oversampling for
							 // temperature and voltage measurements
			uint8_t reserved : 2;
		} fields __attribute__((packed));
		uint8_t value;
	} flags __attribute__((packed));
	struct {
		uint8_t tempdrift_pot_hv_low;
		uint8_t tempdrift_pot_hv_high;
		uint8_t tempdrift_pot_amp_low;
		uint8_t tempdrift_pot_amp_high;
		uint8_t tempdrift_pot_det_low;
		uint8_t tempdrift_pot_det_high;
	} temp_drift_compensation_ranges __attribute__((packed));
} __attribute__((packed)) config_t;

extern config_t config;

#endif // CONFIG_H