/*
 * button.c - Call functions if GPIO pins are high
 * Copyright (C) 2024  Alexander Rosenberg
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version. See the LICENSE file for more information.
 */
#include "button.h"
#include "util.h"

#include <sys/time.h>

static const struct timespec DEBOUNCE_TIME = {
    .tv_sec = 0,
    .tv_nsec = 10 * 1000 * 1000, // 10ms
};

Button *button_new(gpio_handle_t handle, gpio_pin_t pin) {
    Button *button = malloc_checked(sizeof(Button));
    button->handle = handle;
    button->pin = pin;
    gpio_config_t cfg = {
        .g_pin = pin,
        .g_flags = GPIO_PIN_INPUT | GPIO_PIN_PULLUP,
    };
    gpio_pin_set_flags(handle, &cfg);
    button->is_down = false;
    timespecclear(&button->last_detect);
    return button;
}

void button_delete(Button *button) {
    free(button);
}

bool button_pressed(Button *button) {
    struct timespec cur_time, diff_time;
    clock_gettime(CLOCK_UPTIME, &cur_time);
    timespecsub(&cur_time, &button->last_detect, &diff_time);
    if (timespeccmp(&diff_time, &DEBOUNCE_TIME, >=)) {
        gpio_value_t status = gpio_pin_get(button->handle, button->pin);
        if (!button->is_down && status == GPIO_PIN_LOW) {
            button->is_down = true;
            button->last_detect= cur_time;
            return true;
        } else if (button->is_down && status == GPIO_PIN_HIGH) {
            button->last_detect = cur_time;
            button->is_down = false;
        }
    }
    return false;
}