/* Reflow Oven Controller
*
* Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
*
* This file is part of the Reflow Oven Controller Project.
*
* The reflow oven controller is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* The Reflow Oven Control Firmware is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the reflow oven controller project.
* If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef __SETTINGS_SETTINGS_H__
#define __SETTINGS_SETTINGS_H__

#include <stdbool.h>

/**
 * @brief Settings for the PID controller that are stored in the config file
 */
struct oven_pid_settings {
	float kd; /**< @brief Derivate term */
	float kp; /**< @brief Proportional term */
	float ki; /**< @brief Integral term */
	float kd_tau; /**< @brief Time constant of the derivate term's low pass filter */
	float t_sample; /**< @brief Sampling time in seconds. @warning The loading function expects the file to hold a ms value */
	float max_integral; /**< @brief Maximum value of the intgral term */
};

/**
 * @brief Results of a setting loading
 */
enum settings_load_result {
	SETT_LOAD_SUCCESS = 0, /**< @brief Setting loaded successfully */
	SETT_LOAD_FILE_NOT_FOUND, /**< @brief File not found. This is only used by Settings on the SD card */
	SETT_LOAD_ERR, /**< @brief Generic loading error */
	SETT_LOAD_DISK_ERR, /**< @brief Disk access failure during loading */
};

#define SETTINGS_PID_PARAMETER_FILE "pid.conf"

/**
 * @brief Save the calibration
 * @param sens_deviation
 * @param offset
 * @return 0 if successful, -1 if generic error, -2 if medium unavailable
 */
int settings_save_calibration(float sens_deviation, float offset, bool active);

/**
 * @brief Load the calibration
 *
 * If an EEPROM is present, it is first tried to be retrieved from EEPROM.
 * If there is no EEPROM or there is no valid data inside, it is tried to be loaded from SD card.
 *
 * @param sens_dev Sensiotivity deviation
 * @param offset Offset
 * @return 0 if successful and calibration valid
 */
int settings_load_calibration(float *sens_dev, float *offset);

/**
 * @brief Load PID overn parameters from file on SD card. This function is not implemented for EEPROM.
 * @param settings settings
 * @return Load result
 */
enum settings_load_result settings_load_pid_oven_parameters(struct oven_pid_settings *settings);

/**
 * @brief read the configured overtemperature limit
 * @param[out] over_temp_limit Overtemperature limit in degrees Celsius
 * @return Load result
 */
enum settings_load_result settings_load_overtemp_limit(float *over_temp_limit);

/**
 * @brief Save the overtemperature limit
 * @param over_temp_limit Limit in degrees Celsius
 * @param active Overtemperature limit active. If false: The config is delted and the controller uses its default limit
 * @return 0 if successful
 */
int settings_save_overtemp_limit(float over_temp_limit, bool active);

/**
 * @brief Setup the settings module
 *
 * This function has to be called before performing any settings operations.
 * It checks if an EEPTROM is connected and sets the appropriate settings storage in this case.
 *
 * EEPROM storage will only be available for HW versions > 1.3. Some functions require an EEPROM because the counterpart
 * on the SD card is not defined. These functions will fail without an EEPROM.
 */
void settings_setup(void);

#endif /* __SETTINGS_SETTINGS_H__ */