/* Copyright (c) 2025 Rodrigo Arias Mallo <rodarima@gmail.com>
 * SPDX-License-Identifier: GPL-3.0-or-later */

#include "heater.h"

#define HEATER_T_ON	500UL /* ms */
#define HEATER_T_OFF	5000UL /* ms */

void
heater_on(struct heater *h, unsigned long t_ms)
{
	if (h->st == HEATER_ON)
		return;

	h->next_t = t_ms + HEATER_T_ON;
	h->st = HEATER_ON;
	h->turn_on = 1;
}

void
heater_off(struct heater *h)
{
	h->st = HEATER_OFF;
	h->turn_on = 0;
}

int
heater_state(struct heater *h, unsigned long t_ms)
{
	if (h->st == HEATER_OFF)
		return 0;

	/* Switch state if current time exceeds time limit
	 * in the current state */
	/* FIXME: Integer overflow can cause the heater to turn on forever */
	if (t_ms > h->next_t) {
		if (h->turn_on) {
			h->turn_on = 0;
			h->next_t = t_ms + HEATER_T_OFF; 
		} else {
			h->turn_on = 1;
			h->next_t = t_ms + HEATER_T_ON; 
		}
	}

	return h->turn_on;
}