#include "input.h"
#include <fcntl.h>
#include <gint/keyboard.h>
#include <sys/stat.h>
#include <unistd.h>

static struct Input input;
static const int default_map[K_COUNT] = {
    KEY_LEFT, KEY_RIGHT, KEY_UP, KEY_DOWN, KEY_SHIFT, KEY_ALPHA, KEY_EXIT,
    KEY_TAN,  KEY_F3,    KEY_F2, KEY_F1,   KEY_F4,    KEY_F5,    KEY_F6};
static const char *replay_path = "jtmm2.fls";

static void next_state(int i, int kdown);
static PackedFrame pack_frame(void);
static void unpack_frame(PackedFrame);

void
input_init(void)
{

	int i = K_COUNT;
	while (i-- > 0) {
		input.keys[i] = default_map[i];
		input.states[i] = KS_UP;
	}
	i = REPLAY_SIZE;
	input.replay_cursor = 0;
	input.playback = 0;
}

void
input_update(void)
{
	int i = K_COUNT;
	clearevents();
	while (i-- > K_EXIT) {
		const int kdown = keydown(input.keys[i]);
		next_state(i, kdown);
	}
	if (input.playback) {
		unpack_frame(input.replay[input.replay_cursor++]);
		if (input.replay_cursor >= input.replay_end ||
		    input.replay_cursor >= REPLAY_SIZE) {
			input.replay_cursor--;
			input.playback = 0;
		}
	} else {
		i++;
		while (i-- > 0) {
			const int kdown = keydown(input.keys[i]);
			next_state(i, kdown);
		}
		input.replay[input.replay_cursor++] = pack_frame();
		if (input.replay_cursor >= REPLAY_SIZE) input.replay_cursor--;
	}
}

void
input_dump_replay(void)
{
	const int fd = open(replay_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
	if (fd != -1) {
		write(fd, input.replay,
		      input.replay_cursor * sizeof(PackedFrame));
		close(fd);
	}
}

void
input_load_replay(void)
{
	const int fd = open(replay_path, O_RDONLY);
	if (fd != -1) {
		input.playback = 1;
		input.replay_cursor = 0;
		input.replay_end =
		    read(fd, input.replay, REPLAY_SIZE) / sizeof(PackedFrame);
		if (!input.replay_end) input.replay_cursor = REPLAY_SIZE;
		close(fd);
	}
}

void
input_set_down(enum Key k)
{
	input.states[k] = KS_DOWN;
}

void
input_set_pressed(enum Key k)
{
	input.states[k] = KS_PRESS;
}

void
input_set_up(enum Key k)
{
	input.states[k] = KS_UP;
}

int
input_down(enum Key k)
{
	return input.states[k] != KS_UP;
}

int
input_pressed(enum Key k)
{
	return input.states[k] == KS_PRESS;
}

int
input_up(enum Key k)
{
	return input.states[k] == KS_UP;
}

static void
next_state(int i, int kdown)
{
	input.states[i] = (input.states[i] == KS_UP)
	                      ? (kdown ? KS_PRESS : KS_UP)
	                      : (kdown ? KS_DOWN : KS_UP);
}

static PackedFrame
pack_frame(void)
{
	PackedFrame r = 0;
	int i = K_EXIT;
	while (i-- > 0)
		r |= input_down(i) << i;
	return r;
}

static void
unpack_frame(PackedFrame f)
{
	int i = K_EXIT;
	while (i-- > 0)
		next_state(i, (f & (1 << i)) != 0);
}