#include <string.h>

#include "hardware/gpio.h"

#include "pinout.h"

#include "buttons.h"

static const uint8_t m_pins[NUM_BUTTONS] = {
	BTN_ON_PIN,
	BTN_OFF_PIN
};

static uint8_t m_events[NUM_BUTTONS];
static uint32_t m_last_change_time[NUM_BUTTONS];
static uint32_t m_states;

void buttons_init(void)
{
	for(int i = 0; i < NUM_BUTTONS; i++) {
		gpio_init(m_pins[i]);
		gpio_set_dir(m_pins[i], false); // true = output
		gpio_set_pulls(m_pins[i], true, false); // enable pullup
	}

	memset(m_events, 0, sizeof(m_events));
	memset(m_last_change_time, 0, sizeof(m_last_change_time));

	m_states = 0;
}

void buttons_update_state(uint32_t time_ms)
{
	for(int i = 0; i < NUM_BUTTONS; i++) {
		bool is_pressed  = !gpio_get(m_pins[i]); // buttons are active low
		bool was_pressed = ((m_states >> i) & 0x1) != 0;

		m_events[i] = 0;
		if(is_pressed && !was_pressed) {
			m_events[i] |= BTN_EVENT_PRESSED;
			m_states |= (1 << i);
			m_last_change_time[i] = time_ms;
		} else if(!is_pressed && was_pressed) {
			m_events[i] |= BTN_EVENT_RELEASED;
			m_states &= ~(1 << i);
			m_last_change_time[i] = time_ms;
		}
	}
}

uint8_t buttons_get_events(button_id_t button)
{
	return m_events[button];
}

bool buttons_is_pressed(button_id_t button)
{
	return (m_states & (1 << button)) != 0;
}

uint32_t buttons_get_last_change_time(button_id_t button)
{
	return m_last_change_time[button];
}