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

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

void led_on(struct led *led)
{
	led->mode = LED_ON;
}

void led_off(struct led *led)
{
	led->mode = LED_OFF;
}

void led_pattern(struct led *led, unsigned long t_ms, unsigned long period_ms, const char *pattern)
{
	int n = strlen(pattern);
	unsigned long step_ms = period_ms / n;

	/* Don't change the current state */
	if (led->mode == LED_PATTERN &&
			led->step_ms == step_ms &&
			led->pattern == pattern)
		return;

	led->mode = LED_PATTERN;
	led->pat_i = 0;
	led->pat_n = n;
	led->pattern = pattern;
	led->step_ms = step_ms;
	led->t_ms = t_ms;
}

/* Return led level brightness in [0, 255] at current time */
int led_level(struct led *led, unsigned long t_ms)
{
	if (led->mode == LED_OFF)
		return 0;

	if (led->mode == LED_ON)
		return 255;

	if (led->mode == LED_PATTERN) {
		while (led->t_ms + led->step_ms < t_ms) {
			led->t_ms += led->step_ms;
			led->pat_i++;
			if (led->pat_i >= led->pat_n)
				led->pat_i = 0;
		}

		int c = led->pattern[led->pat_i];
		int level;

		if (c >= '0' && c <= '9')
			level = 17 * (c - '0');
		else
			level = 17 * (10 + (c - 'a'));

		if (level < 0)
			level = 0;
		else if (level > 255)
			level = 255;

		return level;
	}

	/* Unknown mode, turn off */
	return 0;
}