/* 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/>.
*/

/**
 * @addtogroup safety-controller
 * @{
 */

#include <reflow-controller/safety/safety-controller.h>
#include <reflow-controller/safety/safety-config.h>
#include <reflow-controller/safety/watchdog.h>
#include <reflow-controller/safety/safety-adc.h>
#include <helper-macros/helper-macros.h>
#include <reflow-controller/systick.h>

#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>

struct error_flag {
	const char *name;
	enum safety_flag flag;
	bool error_state;
	bool persistent;
};

struct timing_mon {
	const char *name;
	enum timing_monitor monitor;
	enum safety_flag associated_flag;
	uint64_t min_delta;
	uint64_t max_delta;
	uint64_t last;
	bool enabled;
};

struct analog_mon {
	const char *name;
	enum analog_value_monitor monitor;
	enum safety_flag associated_flag;
	float min;
	float max;
	float value;
	bool valid;
};

#ifdef COUNT_OF
#undef COUNT_OF
#endif

#define COUNT_OF(x) ((sizeof(x)/sizeof(0[x])) / ((size_t)(!(sizeof(x) % sizeof(0[x])))))

#define ERR_FLAG_ENTRY(errflag, persistency) {.name=#errflag, .flag = (errflag), .error_state = false, .persistent = (persistency)}
#define TIM_MON_ENTRY(mon, min, max, flag) {.name=#mon, .monitor = (mon), .associated_flag=(flag), .min_delta = (min), .max_delta = (max), .last = 0ULL, .enabled= false}
#define ANA_MON_ENTRY(mon, min_value, max_value, flag) {.name=#mon, .monitor = (mon), .associated_flag=(flag), .min = (min_value), .max = (max_value), .value = 0.0f, .valid = false}

static struct error_flag flags[] = {
	ERR_FLAG_ENTRY(ERR_FLAG_MEAS_ADC_OFF, false),
	ERR_FLAG_ENTRY(ERR_FLAG_MEAS_ADC_WATCHDOG, false),
	ERR_FLAG_ENTRY(ERR_FLAG_MEAS_ADC_UNSTABLE, false),
	ERR_FLAG_ENTRY(ERR_FLAG_MEAS_ADC_OVERFLOW, true),
	ERR_FLAG_ENTRY(ERR_FLAG_TIMING_MEAS_ADC, false),
	ERR_FLAG_ENTRY(ERR_FLAG_TIMING_PID, false),
	ERR_FLAG_ENTRY(ERR_FLAG_AMON_UC_TEMP, true),
	ERR_FLAG_ENTRY(ERR_FLAG_AMON_VREF, false),
	ERR_FLAG_ENTRY(ERR_FLAG_STACK, true),
};

static struct timing_mon timings[] = {
	TIM_MON_ENTRY(ERR_TIMING_PID, 1, 800, ERR_FLAG_TIMING_PID),
	TIM_MON_ENTRY(ERR_TIMING_MEAS_ADC, 1, 50, ERR_FLAG_TIMING_MEAS_ADC),
};

static struct analog_mon analog_mons[] = {
	ANA_MON_ENTRY(ERR_AMON_VREF, 2480.0f, 2520.0f, ERR_FLAG_AMON_VREF),
	ANA_MON_ENTRY(ERR_AMON_UC_TEMP, 0.0f, 55.0f, ERR_FLAG_AMON_UC_TEMP),
};

static struct analog_mon *find_analog_mon(enum analog_value_monitor mon)
{
	uint32_t i;
	struct analog_mon *ret = NULL;

	for (i = 0; i < COUNT_OF(analog_mons); i++) {
		if (analog_mons[i].monitor == mon)
			ret = &analog_mons[i];
	}

	return ret;
}

static struct timing_mon *find_timing_mon(enum timing_monitor mon)
{
	uint32_t i;
	struct timing_mon *ret = NULL;

	for (i = 0; i < COUNT_OF(timings); i++) {
		if (timings[i].monitor == mon)
			ret = &timings[i];
	}

	return ret;
}

static struct error_flag *find_error_flag(enum safety_flag flag)
{
	uint32_t i;
	struct error_flag *ret = NULL;

	for (i = 0; i < COUNT_OF(flags); i++) {
		if (flags[i].flag == flag)
			ret = &flags[i];
	}

	return ret;
}

static void safety_controller_process_checks()
{
	// TODO: Implement
}

int safety_controller_report_error(enum safety_flag flag)
{
	uint32_t i;
	int ret = -1;

	for (i = 0; i < COUNT_OF(flags); i++) {
		if (flags[i].flag & flag) {
			flags[i].error_state = true;
			ret = 0;
		}
	}

	safety_controller_process_checks();

	return ret;
}

void safety_controller_report_timing(enum timing_monitor monitor)
{
	uint32_t i;
	struct timing_mon *tim;
	uint64_t timestamp;

	timestamp = systick_get_global_tick();

	tim = find_timing_mon(monitor);
	if (tim) {
		tim->last = timestamp;
		tim->enabled = true;
	}

	safety_controller_process_checks();
}

void safety_controller_report_analog_value(enum analog_value_monitor monitor, float value)
{
	struct analog_mon *ana;

	/* Return if not a power of two */
	if (!is_power_of_two(monitor))
		return;
	ana = find_analog_mon(monitor);
	if (ana) {
		ana->valid = true;
		ana->value = value;
	}

	safety_controller_process_checks();
}

void safety_controller_init()
{
	safety_adc_init();
	watchdog_setup(WATCHDOG_PRESCALER);
}

int safety_controller_handle()
{
	static

	int ret = 0;

	/* TODO: Handle safety ADC */

	/* TODO: Check flags for PID and HALT */

	ret |= watchdog_ack(WATCHDOG_MAGIC_KEY);

	return (ret ? -1 : 0);
}

int safety_controller_enable_timing_mon(enum timing_monitor monitor, bool enable)
{
	struct timing_mon *tim;

	if (enable) {
		safety_controller_report_timing(monitor);
	} else {
		tim = find_timing_mon(monitor);
		if (!tim)
			return -1;
		tim->enabled = false;
	}

	return 0;
}

enum analog_monitor_status safety_controller_get_analog_mon_value(enum analog_value_monitor monitor, float *value)
{
	struct analog_mon *mon;
	int ret = ANALOG_MONITOR_ERROR;

	if (!is_power_of_two(monitor))
		goto go_out;

	if (!value)
		goto go_out;

	mon = find_analog_mon(monitor);
	if (mon) {
		if (!mon->valid) {
			ret = ANALOG_MONITOR_INACTIVE;
			goto go_out;
		}

		*value = mon->value;
		if (mon->value < mon->min)
			ret = ANALOG_MONITOR_UNDER;
		else if (mon->value > mon->max)
			ret = ANALOG_MONITOR_OVER;
		else
			ret = ANALOG_MONITOR_OK;
	}

go_out:
	return ret;
}

/** @} */