/*
 * Copyright © 2013 Jonas Ådahl
 *
 * Permission to use, copy, modify, distribute, and sell this software and
 * its documentation for any purpose is hereby granted without fee, provided
 * that the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of the copyright holders not be used in
 * advertising or publicity pertaining to distribution of the software
 * without specific, written prior permission.  The copyright holders make
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
 * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef LIBINPUT_PRIVATE_H
#define LIBINPUT_PRIVATE_H

#include <errno.h>
#include <math.h>

#include "linux/input.h"

#include "libinput.h"
#include "libinput-util.h"

struct libinput_source;

/* A coordinate pair in device coordinates */
struct device_coords {
	int x, y;
};

/*
 * A coordinate pair in device coordinates, capable of holding non discrete
 * values, this is necessary e.g. when device coordinates get averaged.
 */
struct device_float_coords {
	double x, y;
};

/* A dpi-normalized coordinate pair */
struct normalized_coords {
	double x, y;
};

/* A discrete step pair (mouse wheels) */
struct discrete_coords {
	int x, y;
};

struct libinput_interface_backend {
	int (*resume)(struct libinput *libinput);
	void (*suspend)(struct libinput *libinput);
	void (*destroy)(struct libinput *libinput);
	int (*device_change_seat)(struct libinput_device *device,
				  const char *seat_name);
};

struct libinput {
	int epoll_fd;
	struct list source_destroy_list;

	struct list seat_list;

	struct {
		struct list list;
		struct libinput_source *source;
		int fd;
	} timer;

	struct libinput_event **events;
	size_t events_count;
	size_t events_len;
	size_t events_in;
	size_t events_out;

	const struct libinput_interface *interface;
	const struct libinput_interface_backend *interface_backend;

	libinput_log_handler log_handler;
	enum libinput_log_priority log_priority;
	void *user_data;
	int refcount;
};

typedef void (*libinput_seat_destroy_func) (struct libinput_seat *seat);

struct libinput_seat {
	struct libinput *libinput;
	struct list link;
	struct list devices_list;
	void *user_data;
	int refcount;
	libinput_seat_destroy_func destroy;

	char *physical_name;
	char *logical_name;

	uint32_t slot_map;

	uint32_t button_count[KEY_CNT];
};

struct libinput_device_config_tap {
	int (*count)(struct libinput_device *device);
	enum libinput_config_status (*set_enabled)(struct libinput_device *device,
						   enum libinput_config_tap_state enable);
	enum libinput_config_tap_state (*get_enabled)(struct libinput_device *device);
	enum libinput_config_tap_state (*get_default)(struct libinput_device *device);
};

struct libinput_device_config_calibration {
	int (*has_matrix)(struct libinput_device *device);
	enum libinput_config_status (*set_matrix)(struct libinput_device *device,
						  const float matrix[6]);
	int (*get_matrix)(struct libinput_device *device,
			  float matrix[6]);
	int (*get_default_matrix)(struct libinput_device *device,
							  float matrix[6]);
};

struct libinput_device_config_send_events {
	uint32_t (*get_modes)(struct libinput_device *device);
	enum libinput_config_status (*set_mode)(struct libinput_device *device,
						   enum libinput_config_send_events_mode mode);
	enum libinput_config_send_events_mode (*get_mode)(struct libinput_device *device);
	enum libinput_config_send_events_mode (*get_default_mode)(struct libinput_device *device);
};

struct libinput_device_config_accel {
	int (*available)(struct libinput_device *device);
	enum libinput_config_status (*set_speed)(struct libinput_device *device,
						 double speed);
	double (*get_speed)(struct libinput_device *device);
	double (*get_default_speed)(struct libinput_device *device);
};

struct libinput_device_config_natural_scroll {
	int (*has)(struct libinput_device *device);
	enum libinput_config_status (*set_enabled)(struct libinput_device *device,
						   int enabled);
	int (*get_enabled)(struct libinput_device *device);
	int (*get_default_enabled)(struct libinput_device *device);
};

struct libinput_device_config_left_handed {
	int (*has)(struct libinput_device *device);
	enum libinput_config_status (*set)(struct libinput_device *device, int left_handed);
	int (*get)(struct libinput_device *device);
	int (*get_default)(struct libinput_device *device);
};

struct libinput_device_config_scroll_method {
	uint32_t (*get_methods)(struct libinput_device *device);
	enum libinput_config_status (*set_method)(struct libinput_device *device,
						  enum libinput_config_scroll_method method);
	enum libinput_config_scroll_method (*get_method)(struct libinput_device *device);
	enum libinput_config_scroll_method (*get_default_method)(struct libinput_device *device);
	enum libinput_config_status (*set_button)(struct libinput_device *device,
						  uint32_t button);
	uint32_t (*get_button)(struct libinput_device *device);
	uint32_t (*get_default_button)(struct libinput_device *device);
};

struct libinput_device_config_click_method {
	uint32_t (*get_methods)(struct libinput_device *device);
	enum libinput_config_status (*set_method)(struct libinput_device *device,
						  enum libinput_config_click_method method);
	enum libinput_config_click_method (*get_method)(struct libinput_device *device);
	enum libinput_config_click_method (*get_default_method)(struct libinput_device *device);
};

struct libinput_device_config {
	struct libinput_device_config_tap *tap;
	struct libinput_device_config_calibration *calibration;
	struct libinput_device_config_send_events *sendevents;
	struct libinput_device_config_accel *accel;
	struct libinput_device_config_natural_scroll *natural_scroll;
	struct libinput_device_config_left_handed *left_handed;
	struct libinput_device_config_scroll_method *scroll_method;
	struct libinput_device_config_click_method *click_method;
};

struct libinput_device_group {
	int refcount;
	void *user_data;
	char *identifier; /* unique identifier or NULL for singletons */
};

struct libinput_device {
	struct libinput_seat *seat;
	struct libinput_device_group *group;
	struct list link;
	struct list event_listeners;
	void *user_data;
	int refcount;
	struct libinput_device_config config;
};

struct libinput_event {
	enum libinput_event_type type;
	struct libinput_device *device;
};

struct libinput_event_listener {
	struct list link;
	void (*notify_func)(uint64_t time, struct libinput_event *ev, void *notify_func_data);
	void *notify_func_data;
};

typedef void (*libinput_source_dispatch_t)(void *data);

#define log_debug(li_, ...) log_msg((li_), LIBINPUT_LOG_PRIORITY_DEBUG, __VA_ARGS__)
#define log_info(li_, ...) log_msg((li_), LIBINPUT_LOG_PRIORITY_INFO, __VA_ARGS__)
#define log_error(li_, ...) log_msg((li_), LIBINPUT_LOG_PRIORITY_ERROR, __VA_ARGS__)
#define log_bug_kernel(li_, ...) log_msg((li_), LIBINPUT_LOG_PRIORITY_ERROR, "kernel bug: " __VA_ARGS__)
#define log_bug_libinput(li_, ...) log_msg((li_), LIBINPUT_LOG_PRIORITY_ERROR, "libinput bug: " __VA_ARGS__)
#define log_bug_client(li_, ...) log_msg((li_), LIBINPUT_LOG_PRIORITY_ERROR, "client bug: " __VA_ARGS__)

void
log_msg(struct libinput *libinput,
	enum libinput_log_priority priority,
	const char *format, ...);

void
log_msg_va(struct libinput *libinput,
	   enum libinput_log_priority priority,
	   const char *format,
	   va_list args);

int
libinput_init(struct libinput *libinput,
	      const struct libinput_interface *interface,
	      const struct libinput_interface_backend *interface_backend,
	      void *user_data);

struct libinput_source *
libinput_add_fd(struct libinput *libinput,
		int fd,
		libinput_source_dispatch_t dispatch,
		void *data);

void
libinput_remove_source(struct libinput *libinput,
		       struct libinput_source *source);

int
open_restricted(struct libinput *libinput,
		const char *path, int flags);

void
close_restricted(struct libinput *libinput, int fd);

void
libinput_seat_init(struct libinput_seat *seat,
		   struct libinput *libinput,
		   const char *physical_name,
		   const char *logical_name,
		   libinput_seat_destroy_func destroy);

void
libinput_device_init(struct libinput_device *device,
		     struct libinput_seat *seat);

struct libinput_device_group *
libinput_device_group_create(const char *identifier);

void
libinput_device_set_device_group(struct libinput_device *device,
				 struct libinput_device_group *group);

void
libinput_device_add_event_listener(struct libinput_device *device,
				   struct libinput_event_listener *listener,
				   void (*notify_func)(
						uint64_t time,
						struct libinput_event *event,
						void *notify_func_data),
				   void *notify_func_data);

void
libinput_device_remove_event_listener(struct libinput_event_listener *listener);

void
notify_added_device(struct libinput_device *device);

void
notify_removed_device(struct libinput_device *device);

void
keyboard_notify_key(struct libinput_device *device,
		    uint64_t time,
		    uint32_t key,
		    enum libinput_key_state state);

void
pointer_notify_motion(struct libinput_device *device,
		      uint64_t time,
		      const struct normalized_coords *delta,
		      const struct normalized_coords *unaccel);

void
pointer_notify_motion_absolute(struct libinput_device *device,
			       uint64_t time,
			       const struct device_coords *point);

void
pointer_notify_button(struct libinput_device *device,
		      uint64_t time,
		      int32_t button,
		      enum libinput_button_state state);

void
pointer_notify_axis(struct libinput_device *device,
		    uint64_t time,
		    uint32_t axes,
		    enum libinput_pointer_axis_source source,
		    const struct normalized_coords *delta,
		    const struct discrete_coords *discrete);

void
touch_notify_touch_down(struct libinput_device *device,
			uint64_t time,
			int32_t slot,
			int32_t seat_slot,
			const struct device_coords *point);

void
touch_notify_touch_motion(struct libinput_device *device,
			  uint64_t time,
			  int32_t slot,
			  int32_t seat_slot,
			  const struct device_coords *point);

void
touch_notify_touch_up(struct libinput_device *device,
		      uint64_t time,
		      int32_t slot,
		      int32_t seat_slot);

void
touch_notify_frame(struct libinput_device *device,
		   uint64_t time);

static inline uint64_t
libinput_now(struct libinput *libinput)
{
	struct timespec ts = { 0, 0 };

	if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) {
		log_error(libinput, "clock_gettime failed: %s\n", strerror(errno));
		return 0;
	}

	return ts.tv_sec * 1000ULL + ts.tv_nsec / 1000000;
}

static inline struct device_float_coords
device_delta(struct device_coords a, struct device_coords b)
{
	struct device_float_coords delta;

	delta.x = a.x - b.x;
	delta.y = a.y - b.y;

	return delta;
}

static inline double
normalized_length(struct normalized_coords norm)
{
	return hypot(norm.x, norm.y);
}

static inline int
normalized_is_zero(struct normalized_coords norm)
{
	return norm.x == 0.0 && norm.y == 0.0;
}

enum directions {
	N  = 1 << 0,
	NE = 1 << 1,
	E  = 1 << 2,
	SE = 1 << 3,
	S  = 1 << 4,
	SW = 1 << 5,
	W  = 1 << 6,
	NW = 1 << 7,
	UNDEFINED_DIRECTION = 0xff
};

static inline int
normalized_get_direction(struct normalized_coords norm)
{
	int dir = UNDEFINED_DIRECTION;
	int d1, d2;
	double r;

	if (fabs(norm.x) < 2.0 && fabs(norm.y) < 2.0) {
		if (norm.x > 0.0 && norm.y > 0.0)
			dir = S | SE | E;
		else if (norm.x > 0.0 && norm.y < 0.0)
			dir = N | NE | E;
		else if (norm.x < 0.0 && norm.y > 0.0)
			dir = S | SW | W;
		else if (norm.x < 0.0 && norm.y < 0.0)
			dir = N | NW | W;
		else if (norm.x > 0.0)
			dir = NE | E | SE;
		else if (norm.x < 0.0)
			dir = NW | W | SW;
		else if (norm.y > 0.0)
			dir = SE | S | SW;
		else if (norm.y < 0.0)
			dir = NE | N | NW;
	} else {
		/* Calculate r within the interval  [0 to 8)
		 *
		 * r = [0 .. 2π] where 0 is North
		 * d_f = r / 2π  ([0 .. 1))
		 * d_8 = 8 * d_f
		 */
		r = atan2(norm.y, norm.x);
		r = fmod(r + 2.5*M_PI, 2*M_PI);
		r *= 4*M_1_PI;

		/* Mark one or two close enough octants */
		d1 = (int)(r + 0.9) % 8;
		d2 = (int)(r + 0.1) % 8;

		dir = (1 << d1) | (1 << d2);
	}

	return dir;
}

#endif /* LIBINPUT_PRIVATE_H */