/* 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/>.
*/

#include <reflow-controller/settings/settings-sd-card.h>
#include <stm-periph/unique-id.h>
#include <toml/toml.h>
#include <fatfs/ff.h>

static void get_controller_folder_path(char *path, size_t size)
{
	uint32_t high;
	uint32_t mid;
	uint32_t low;

	if (!path)
		return;

	unique_id_get(&high, &mid, &low);

	snprintf(path, size, "/%08X-%08X-%08X",
		 (unsigned int)high, (unsigned int)mid, (unsigned int)low);
}

/**
 * @brief Open or create the controller folder on the SD Card.
 * @param[in,out] controller_folder
 * @return 0 if opened, 1 if created and opened, -1 if error.
 */
static int open_or_create_controller_folder(DIR *controller_folder)
{
	char foldername[48];
	int ret = -1;
	FRESULT filesystem_result;

	if (!controller_folder)
		return -1001;

	get_controller_folder_path(foldername, sizeof(foldername));

	/* Check if folder is present */
	filesystem_result = f_opendir(controller_folder, foldername);
	if (filesystem_result == FR_OK) {
		ret = 0;
	} else {
		filesystem_result = f_mkdir(foldername);
		if (filesystem_result == FR_OK) {
			filesystem_result = f_opendir(controller_folder, foldername);
			if (filesystem_result == FR_OK)
				ret = 1;
			else
				ret = -1;
		} else {
			ret = -1;
		}
	}

	if (ret >= 0)
		f_chdir(foldername);

	return ret;
}

int sd_card_settings_save_calibration(float sens_deviation, float offset, bool active)
{
	DIR folder;
	FIL cal_file;
	int status;
	FRESULT res;
	UINT bw;
	int ret = 0;
	char buff[256];

	status = open_or_create_controller_folder(&folder);
	f_closedir(&folder);

	if (status < 0)
		return -2;

	/* Create new calibration file */
	res = f_open(&cal_file, CALIBRATION_FILE_NAME, FA_CREATE_ALWAYS | FA_WRITE);
	if (res == FR_OK) {
		status = snprintf(buff, sizeof(buff), "[cal]\noffset = %f\nsensdev = %f\nactive = %s\n",
				  offset, sens_deviation, (active ? "true" : "false"));

		if ((unsigned int)status < sizeof(buff) && status >= 0) {
			f_write(&cal_file, buff, status, &bw);
			if (bw == (unsigned int)status)
				ret = 0;
			else
				ret = -3;
		} else {
			ret = -4;
		}

		f_close(&cal_file);

	} else {
		ret = -1;
	}

	f_chdir("/");

	return ret;
}