/* SPDX-License-Identifier: GPL-3.0-only */
/*
 * Copyright (c) 2024, Richard Acayan. All rights reserved.
 */

#ifndef UFKBD_H
#define UFKBD_H

#include <stdbool.h>
#include <time.h>
#include <xkbcommon/xkbcommon.h>

#define UFKBD_PRESS_MAX 64
#define UFKBD_MOD_MAX 4

struct ufkbd_ctx;
struct ufkbd_graphics_ctx;
struct ufkbd_graphics_driver;
struct ufkbd_input_driver;

// These correspond to the key0..key8 properties in the layout definitions
enum ufkbd_part {
	UFKBD_PART_CENTER,
	UFKBD_PART_TL,
	UFKBD_PART_TR,
	UFKBD_PART_BL,
	UFKBD_PART_BR,
	UFKBD_PART_LEFT,
	UFKBD_PART_RIGHT,
	UFKBD_PART_TOP,
	UFKBD_PART_BOTTOM,
	UFKBD_PART_MAX
};

enum ufkbd_mod_state {
	UFKBD_MOD_RELEASED,
	UFKBD_MOD_PRESSED,
	UFKBD_MOD_LATCHED,
	UFKBD_MOD_LOCKED,
};

enum ufkbd_modifier {
	UFKBD_MOD_SHIFT,
	UFKBD_MOD_CTRL,
	UFKBD_MOD_ALT,
};

struct ufkbd_key {
	// Graphical parameters
	size_t presses[UFKBD_PART_MAX];
	void *labels_mask[UFKBD_PART_MAX * 2];
	void *labels_color[UFKBD_PART_MAX * 2];

	int keyids[UFKBD_PART_MAX];
	xkb_keysym_t keysyms[UFKBD_PART_MAX];
	enum ufkbd_part lut[16];
	int latch_state;
};

struct ufkbd_driver {
	void *(*init)(struct ufkbd_ctx *ufkbd);
	void (*uninit)(void *data);

	// Deprecated
	void (*listen_one)(void *data, bool block);

	void (*listen_step)(void *data, int timeout);
	int (*send_key)(void *data, int code, bool repeat);
	int (*send_mod)(void *data, enum ufkbd_modifier mod, bool pressed);

	int (*draw_begin)(void *data, size_t *stride, void **ptr);
	void (*draw_touch)(void *data, int x, int y, int width, int height);
	void (*draw_end)(void *data);
};

struct ufkbd_press {
	struct ufkbd_key *key;
	int xl, xr, yt, yb;

	struct timespec repeat;

	// Coordinates of starting and ending position of keypress
	int x1, y1, x2, y2;

	// Cached section of the key that is pressed
	enum ufkbd_part part;
};

struct ufkbd_ctx {
	struct ufkbd_keymap *keymap;
	struct ufkbd_layout *layout;

	struct ufkbd_driver *drv;
	void *drv_data;

	struct ufkbd_graphics_ctx *graphics;

	// Settings
	int repeat_delay_ns;
	int repeat_interval_ns;
	int dist_squared;

	uint32_t mods[(UFKBD_MOD_MAX + 15) / 16];

	size_t n_presses;
	struct ufkbd_press presses[UFKBD_PRESS_MAX];

	bool terminate;
};

void ufkbd_terminate(struct ufkbd_ctx *ctx);

#endif /* UFKBD_H */