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

#include "overheat.h"
#include <string.h>

void
overheat_init(struct overheat *o)
{
	memset(o, 0, sizeof(struct overheat));
}

void
overheat_input(struct overheat *o, unsigned long t_ms, float temp)
{
	unsigned long delta = t_ms - o->last_time;

	if (delta < OVH_INTERVAL)
		return;

	/* If already go n samples, recompute delta and speed */
	if (o->n == OVH_NSAMPLES) {
		float last_T = o->temp[o->next];
		float last_t = o->t[o->next];
		float dt = (float) (t_ms - last_t) * 1e-3;
		o->delta = temp - last_T;
		o->speed = o->delta / dt;
	}

	/* Add the new sample */
	o->temp[o->next] = temp;
	o->t[o->next] = t_ms;
	o->next++;
	if (o->next >= OVH_NSAMPLES)
		o->next = 0;
	if (o->n < OVH_NSAMPLES)
		o->n++;

	o->last_time = t_ms;
}

float
overheat_delta(struct overheat *o)
{
	return o->delta;
}

float
overheat_speed(struct overheat *o)
{
	return o->speed;
}

int
overheat_panic(struct overheat *o)
{
	if (o->speed > OVH_THRESHOLD)
		return 1;
	else
		return 0;
}