#include "input.h"

#include <assert.h>
#include <fcntl.h>
#include <linux/input.h>
#include <string.h>
#include <unistd.h>

enum {
	RELEASE = 0,
	PRESS = 1,
	REPEAT = 2,
};

input_state_t input;

static int input_fd;
static input_callback_t shoot;

static void key_press(int key)
{
	switch (key) {
	case KEY_Q:
		input.quit = true;
		break;

	case KEY_UP:
		++input.thrust;
		break;

	case KEY_LEFT:
		++input.spin;
		break;
	case KEY_RIGHT:
		--input.spin;
		break;

	case KEY_SPACE:
		if (shoot != nullptr)
			shoot();
		break;
	}
}

static void key_release(int key)
{
	switch (key) {
	case KEY_UP:
		--input.thrust;
		break;

	case KEY_LEFT:
		--input.spin;
		break;
	case KEY_RIGHT:
		++input.spin;
		break;
	}
}

static void key_repeat(int key)
{
	if (key == KEY_SPACE && shoot != nullptr)
		shoot();
}

int input_init()
{
	memset(&input, 0, sizeof(input));
	shoot = nullptr;

	input_fd = open("/dev/input/event0", O_RDONLY);
	assert(input_fd != -1);
	const int res = ioctl(input_fd, EVIOCGRAB, (void *)1);
	assert(res != -1);

	return input_fd;
}

void input_cleanup()
{
	ioctl(input_fd, EVIOCGRAB, (void *)0);
	close(input_fd);
}

void input_on_shoot(input_callback_t cb)
{
	shoot = cb;
}

void input_handle()
{
	struct input_event ev;
	const int len = read(input_fd, &ev, sizeof(ev));
	assert(len == sizeof(ev));
	if (ev.type == EV_KEY) {
		switch (ev.value) {
		case PRESS:
			key_press(ev.code);
			break;
		case RELEASE:
			key_release(ev.code);
			break;
		case REPEAT:
			key_repeat(ev.code);
			break;
		}
	}
}