/* SPDX-License-Identifier: MIT */
/*
 * Copyright © 2020 Red Hat, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include "config.h"

#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>

#include "util-io.h"
#include "util-macros.h"
#include "util-object.h"
#include "util-sources.h"
#include "util-strings.h"
#include "util-time.h"
#include "util-version.h"

#include "libei.h"
#include "libei-private.h"
#include "brei-shared.h"
#include "ei-proto.h"

_Static_assert(sizeof(enum ei_device_capability) == sizeof(int), "Invalid enum size");
_Static_assert(sizeof(enum ei_keymap_type) == sizeof(int), "Invalid enum size");
_Static_assert(sizeof(enum ei_event_type) == sizeof(int), "Invalid enum size");
_Static_assert(sizeof(enum ei_log_priority) == sizeof(int), "Invalid enum size");

static struct ei_seat *
ei_find_seat(struct ei *ei, uint32_t seatid)
{
	struct ei_seat *seat;

	list_for_each(seat, &ei->seats, link) {
		if (ei_seat_get_id(seat) == seatid)
			return seat;
	}

	return NULL;
}

static struct ei_device *
ei_find_device(struct ei *ei, uint32_t deviceid)
{
	struct ei_seat *seat;

	list_for_each(seat, &ei->seats, link) {
		struct ei_device *device = ei_seat_find_device(seat, deviceid);
		if (device)
			return device;
	}

	return NULL;
}

static void
ei_destroy(struct ei *ei)
{
	ei_disconnect(ei);

	struct ei_event *e;
	while ((e = ei_get_event(ei)) != NULL)
		ei_event_unref(e);

	if (ei->backend_interface.destroy)
		ei->backend_interface.destroy(ei, ei->backend);
	ei->backend = NULL;
	ei_connection_unref(ei->connection);
	sink_unref(ei->sink);
	free(ei->name);
}

static
OBJECT_IMPLEMENT_CREATE(ei);
_public_
OBJECT_IMPLEMENT_REF(ei);
_public_
OBJECT_IMPLEMENT_UNREF_CLEANUP(ei);
_public_
OBJECT_IMPLEMENT_SETTER(ei, user_data, void *);
_public_
OBJECT_IMPLEMENT_GETTER(ei, user_data, void *);
OBJECT_IMPLEMENT_GETTER(ei, connection, struct ei_connection *);

DEFINE_UNREF_CLEANUP_FUNC(ei_device);
DEFINE_UNREF_CLEANUP_FUNC(ei_region);

struct ei *
ei_get_context(struct ei *ei)
{
	return ei; /* for the protocol bindings */
}

static struct ei *
ei_create_context(bool is_sender, void *user_data)
{
	_unref_(ei) *ei = ei_create(NULL);

	ei->state = EI_STATE_NEW;
	list_init(&ei->event_queue);
	list_init(&ei->seats);
	list_init(&ei->proto_objects);

	ei->connection = ei_connection_new(ei);
	ei->next_object_id = 1;

	ei_log_set_handler(ei, NULL);
	ei_log_set_priority(ei, EI_LOG_PRIORITY_INFO);
	ei->sink = sink_new();
	if (!ei->sink)
		return NULL;

	ei->user_data = user_data;
	ei->backend = NULL;
	ei->is_sender = is_sender;

	return steal(&ei);
}

uint32_t
ei_get_new_id(struct ei *ei)
{
	static const int server_range = 0xff000000;
	return ei->next_object_id++ & ~server_range;
}

void
ei_register_object(struct ei *ei, struct brei_object *object)
{
	log_debug(ei, "registering %s v%u object %#x", object->interface->name, object->version, object->id);
	list_append(&ei->proto_objects, &object->link);
}

void
ei_unregister_object(struct ei *ei, struct brei_object *object)
{
	log_debug(ei, "deregistering %s v%u object %#x", object->interface->name, object->version, object->id);
	list_remove(&object->link);
}

_public_ bool
ei_is_sender(struct ei *ei)
{
	return ei->is_sender;
}

_public_ struct ei *
ei_new(void *user_data)
{
	return ei_new_sender(user_data);
}

_public_ struct ei *
ei_new_sender(void *user_data)
{
	return ei_create_context(true, user_data);
}

_public_ struct ei *
ei_new_receiver(void *user_data)
{
	return ei_create_context(false, user_data);
}

_public_ int
ei_get_fd(struct ei *ei)
{
	return sink_get_fd(ei->sink);
}

_public_ void
ei_dispatch(struct ei *ei)
{
	sink_dispatch(ei->sink);
}

static void
update_event_timestamp(struct ei_event *event, uint64_t time)
{
	switch (event->type) {
	case EI_EVENT_POINTER_MOTION:
	case EI_EVENT_POINTER_MOTION_ABSOLUTE:
	case EI_EVENT_POINTER_BUTTON:
	case EI_EVENT_POINTER_SCROLL:
	case EI_EVENT_POINTER_SCROLL_STOP:
	case EI_EVENT_POINTER_SCROLL_CANCEL:
	case EI_EVENT_POINTER_SCROLL_DISCRETE:
	case EI_EVENT_KEYBOARD_KEY:
	case EI_EVENT_TOUCH_DOWN:
	case EI_EVENT_TOUCH_UP:
	case EI_EVENT_TOUCH_MOTION:
		if (event->timestamp != 0) {
			log_bug(ei_event_get_context(event),
				"Unexpected timestamp for event of type: %s",
				ei_event_type_to_string(event->type));
			return;
		}
		event->timestamp = time;
		break;
	default:
		log_bug(ei_event_get_context(event),
			"Unexpected event %s in pending queue event",
			ei_event_type_to_string(event->type));
		return;
	}
}

static void
queue_event(struct ei *ei, struct ei_event *event)
{
	struct ei_device *device = ei_event_get_device(event);
	struct list *queue = &ei->event_queue;
	const char *prefix = "";

	switch (event->type) {
	case EI_EVENT_POINTER_MOTION:
	case EI_EVENT_POINTER_MOTION_ABSOLUTE:
	case EI_EVENT_POINTER_BUTTON:
	case EI_EVENT_POINTER_SCROLL:
	case EI_EVENT_POINTER_SCROLL_STOP:
	case EI_EVENT_POINTER_SCROLL_CANCEL:
	case EI_EVENT_POINTER_SCROLL_DISCRETE:
	case EI_EVENT_KEYBOARD_KEY:
	case EI_EVENT_TOUCH_DOWN:
	case EI_EVENT_TOUCH_UP:
	case EI_EVENT_TOUCH_MOTION:
		prefix = "pending ";
		queue = &device->pending_event_queue;
		break;
	case EI_EVENT_FRAME:
		/* silently discard empty frames */
		if (list_empty(&device->pending_event_queue))
			return;

		struct ei_event *pending;
		list_for_each_safe(pending, &device->pending_event_queue, link) {
			update_event_timestamp(pending, event->timestamp);
			list_remove(&pending->link);
			list_append(&ei->event_queue, &pending->link);
		}
		break;
	default:
		if (device && !list_empty(&device->pending_event_queue))
				ei_queue_frame_event(device, ei_now(ei));
		break;
	}

	log_debug(ei, "queuing %sevent type %s (%u)",
		  prefix,
		  ei_event_type_to_string(event->type), event->type);

	list_append(queue, &event->link);
}

static void
insert_event(struct ei *ei, struct ei_event *event)
{
	log_debug(ei, "inserting event type %s (%u)",
		  ei_event_type_to_string(event->type), event->type);

	list_insert(&ei->event_queue, &event->link);
}


static void
queue_connect_event(struct ei *ei)
{
	struct ei_event *e = ei_event_new(ei);
	e->type = EI_EVENT_CONNECT;

	queue_event(ei, e);
}

static void
queue_disconnect_event(struct ei *ei)
{
	struct ei_event *e = ei_event_new(ei);
	e->type = EI_EVENT_DISCONNECT;

	queue_event(ei, e);
}

static void
queue_seat_added_event(struct ei_seat *seat)
{
	struct ei *ei= ei_seat_get_context(seat);

	struct ei_event *e = ei_event_new(ei);
	e->type = EI_EVENT_SEAT_ADDED;
	e->seat = ei_seat_ref(seat);

	queue_event(ei, e);
}

static void
queue_seat_removed_event(struct ei_seat *seat)
{
	struct ei *ei= ei_seat_get_context(seat);

	struct ei_event *e = ei_event_new(ei);
	e->type = EI_EVENT_SEAT_REMOVED;
	e->seat = ei_seat_ref(seat);

	queue_event(ei, e);
}

void
ei_queue_seat_removed_event(struct ei_seat *seat)
{
	queue_seat_removed_event(seat);
}

static void
queue_device_added_event(struct ei_device *device)
{
	struct ei *ei= ei_device_get_context(device);
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_DEVICE_ADDED;

	queue_event(ei, e);
}

static void
queue_device_removed_event(struct ei_device *device)
{
	struct ei *ei= ei_device_get_context(device);
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_DEVICE_REMOVED;

	queue_event(ei, e);
}

static void
insert_device_removed_event(struct ei_device *device)
{
	struct ei *ei= ei_device_get_context(device);
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_DEVICE_REMOVED;

	insert_event(ei, e);
}

static void
queue_paused_event(struct ei_device *device)
{
	struct ei *ei= ei_device_get_context(device);
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_DEVICE_PAUSED;

	queue_event(ei, e);
}

static void
queue_resumed_event(struct ei_device *device)
{
	struct ei *ei= ei_device_get_context(device);
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_DEVICE_RESUMED;

	queue_event(ei, e);
}

static void
queue_keyboard_modifiers_event(struct ei_device *device,
			       const struct ei_xkb_modifiers *mods)
{
	struct ei *ei= ei_device_get_context(device);
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_KEYBOARD_MODIFIERS;
	e->modifiers = *mods;

	queue_event(ei, e);
}

void
ei_queue_frame_event(struct ei_device *device, uint64_t time)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_FRAME;
	e->timestamp = time;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_device_start_emulating_event(struct ei_device *device, uint32_t sequence)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_DEVICE_START_EMULATING;
	e->start_emulating.sequence = sequence;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_device_stop_emulating_event(struct ei_device *device)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_DEVICE_STOP_EMULATING;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_pointer_rel_event(struct ei_device *device,
			    double dx, double dy)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_POINTER_MOTION;
	e->pointer.dx = dx;
	e->pointer.dy = dy;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_pointer_abs_event(struct ei_device *device,
			    double x, double y)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_POINTER_MOTION_ABSOLUTE;
	e->pointer.absx = x;
	e->pointer.absy = y;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_pointer_button_event(struct ei_device *device, uint32_t button,
			       bool is_press)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_POINTER_BUTTON;
	e->pointer.button = button;
	e->pointer.button_is_press = is_press;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_pointer_scroll_event(struct ei_device *device,
			       double x, double y)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_POINTER_SCROLL;
	e->pointer.sx = x;
	e->pointer.sy = y;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_pointer_scroll_discrete_event(struct ei_device *device,
					int32_t x, int32_t y)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_POINTER_SCROLL_DISCRETE;
	e->pointer.sdx = x;
	e->pointer.sdy = y;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_pointer_scroll_stop_event(struct ei_device *device, bool x, bool y)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_POINTER_SCROLL_STOP;
	e->pointer.stop_x = x;
	e->pointer.stop_y = y;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_pointer_scroll_cancel_event(struct ei_device *device, bool x, bool y)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_POINTER_SCROLL_CANCEL;
	e->pointer.stop_x = x;
	e->pointer.stop_y = y;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_keyboard_key_event(struct ei_device *device, uint32_t key,
			     bool is_press)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_KEYBOARD_KEY;
	e->keyboard.key = key;
	e->keyboard.key_is_press = is_press;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_touch_down_event(struct ei_device *device, uint32_t touchid,
			   double x, double y)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_TOUCH_DOWN;
	e->touch.touchid = touchid,
	e->touch.x = x;
	e->touch.y = y;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_touch_motion_event(struct ei_device *device, uint32_t touchid,
			     double x, double y)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_TOUCH_MOTION;
	e->touch.touchid = touchid,
	e->touch.x = x;
	e->touch.y = y;

	queue_event(ei_device_get_context(device), e);
}

void
ei_queue_touch_up_event(struct ei_device *device, uint32_t touchid)
{
	struct ei_event *e = ei_event_new_for_device(device);

	e->type = EI_EVENT_TOUCH_UP;
	e->touch.touchid = touchid,

	queue_event(ei_device_get_context(device), e);
}

void
ei_disconnect(struct ei *ei)
{
	if (ei->state == EI_STATE_DISCONNECTED ||
	    ei->state == EI_STATE_DISCONNECTING)
		return;

	enum ei_state state = ei->state;

	/* We need the disconnecting state to be re-entrant
	   ei_device_remove() may call ei_disconnect() on a socket error */
	ei->state = EI_STATE_DISCONNECTING;

	struct ei_seat *seat;
	list_for_each_safe(seat, &ei->seats, link) {
		ei_seat_remove(seat);
	}

	if (state != EI_STATE_NEW) {
		ei_connection_request_disconnect(ei->connection);
	}
	queue_disconnect_event(ei);
	ei->state = EI_STATE_DISCONNECTED;
	if (ei->source)
		source_remove(ei->source);
	ei->source = source_unref(ei->source);
}

static int
handle_msg_seat(struct ei_connection *connection, uint32_t seat_id, uint32_t version)
{
	struct ei *ei = ei_connection_get_context(connection);

	struct ei_seat *seat = ei_seat_new(ei, seat_id, version);

	/* seats list owns the ref */
	list_append(&ei->seats, &seat->link);

	return 0;
}

static int
handle_msg_device_added(struct ei_connection *connection, uint32_t deviceid, uint32_t capabilities,
			const char *name, uint32_t seatid, uint32_t type,
			uint32_t width, uint32_t height)
{
	struct ei *ei = ei_connection_get_context(connection);
	struct ei_seat *seat = ei_find_seat(ei, seatid);

	if (!seat) {
		log_bug(ei, "Invalid seat id %#x for device %s (%#x)",
			seatid, name, deviceid);
		return 0;
	}


	/* Wrong device id or a device already removed by the client but we
	 * won't know which unless we keep some device ID table. Not worth
	 * it, so just silently ignore */
	if (ei_seat_find_device(seat, deviceid)) {
		log_error(ei, "Server sent duplicate device id %#x", deviceid);
		return -EINVAL;
	}

	switch (type) {
		case EI_DEVICE_TYPE_PHYSICAL:
		case EI_DEVICE_TYPE_VIRTUAL:
			break;
		default:
			log_error(ei, "Server sent invalid device type %u", type);
			return -EINVAL;
	}

	_unref_(ei_device) *device = ei_device_new(seat, deviceid);
	ei_device_set_type(device, type);
	if (type == EI_DEVICE_TYPE_PHYSICAL)
		ei_device_set_size(device, width, height);
	ei_device_set_name(device, name);
	ei_device_set_capabilities(device, capabilities);
	ei_device_added(device);

	log_debug(ei,
		  "Added device %#x '%s' caps: %s%s%s%s seat: %s",
		  deviceid, name,
		  ei_device_has_capability(device, EI_DEVICE_CAP_POINTER) ? "p" : "",
		  ei_device_has_capability(device, EI_DEVICE_CAP_POINTER_ABSOLUTE) ? "a" : "",
		  ei_device_has_capability(device, EI_DEVICE_CAP_KEYBOARD) ? "k" : "",
		  ei_device_has_capability(device, EI_DEVICE_CAP_TOUCH) ? "t" : "",
		  ei_seat_get_name(seat));

	return 0;
}

static int
handle_msg_device_keymap(struct ei_connection *connection, uint32_t deviceid,
			enum ei_keymap_type keymap_type,
			uint32_t keymap_sz, int keymap_fd)
{
	struct ei *ei = ei_connection_get_context(connection);

	log_debug(ei, "Adding keymap for %#x", deviceid);

	struct ei_device *device = ei_find_device(ei, deviceid);
	if (!device)
		return 0;

	ei_device_set_keymap(device, keymap_type, keymap_fd, keymap_sz);

	return 0;
}

void
ei_queue_device_removed_event(struct ei_device *device)
{
	queue_device_removed_event(device);
}

void
ei_insert_device_removed_event(struct ei_device *device)
{
	insert_device_removed_event(device);
}

static int
handle_msg_device_added_done(struct ei_connection *connection, uint32_t deviceid)
{
	struct ei *ei = ei_connection_get_context(connection);

	log_debug(ei, "Done with device %#x", deviceid);

	struct ei_device *device = ei_find_device(ei, deviceid);
	if (!device)
		return 0;

	queue_device_added_event(device);
	ei_device_done(device);

	return 0;
}

static int
handle_msg_device_region(struct ei_connection *connection, uint32_t deviceid,
			 uint32_t x, uint32_t y,
			 uint32_t w, uint32_t h,
			 float scale)
{
	struct ei *ei = ei_connection_get_context(connection);

	log_debug(ei, "Adding device region for %#x", deviceid);

	struct ei_device *device = ei_find_device(ei, deviceid);
	if (!device)
		return 0;

	_unref_(ei_region) *r = ei_region_new();
	ei_region_set_offset(r, x, y);
	ei_region_set_size(r, w, h);
	ei_region_set_physical_scale(r, scale);

	ei_device_add_region(device, r);

	return 0;
}

static int
handle_msg_keyboard_modifiers(struct ei_connection *connection, uint32_t deviceid,
			      uint32_t depressed, uint32_t locked,
			      uint32_t latched, uint32_t group)
{
	struct ei *ei = ei_connection_get_context(connection);

	log_debug(ei, "Setting modifiers for %#x", deviceid);

	struct ei_device *device = ei_find_device(ei, deviceid);
	if (!device)
		return 0;

	if (!ei_device_has_capability(device, EI_DEVICE_CAP_KEYBOARD)) {
		log_bug(ei,"Modifier event for non-keyboard");
		return -EPROTO;
	}

	struct ei_xkb_modifiers mods = {
		.depressed = depressed,
		.latched = latched,
		.locked = locked,
		.group = group,
	};
	queue_keyboard_modifiers_event(device, &mods);

	return 0;
}

static int
handle_msg_device_removed(struct ei_connection *connection, uint32_t deviceid)
{
	struct ei *ei = ei_connection_get_context(connection);

	log_debug(ei, "Removed device %#x", deviceid);

	struct ei_device *device = ei_find_device(ei, deviceid);
	if (!device)
		return 0;

	ei_device_removed_by_server(device);

	return 0;
}

static int
handle_msg_device_resumed(struct ei_connection *connection, uint32_t deviceid)
{
	struct ei *ei = ei_connection_get_context(connection);

	log_debug(ei, "Resumed device %#x", deviceid);

	struct ei_device *device = ei_find_device(ei, deviceid);
	if (device) {
		ei_device_resumed(device);
		queue_resumed_event(device);
	}

	return 0;
}

static int
handle_msg_device_paused(struct ei_connection *connection, uint32_t deviceid)
{
	struct ei *ei = ei_connection_get_context(connection);

	log_debug(ei, "Paused device %#x", deviceid);

	struct ei_device *device = ei_find_device(ei, deviceid);
	if (device) {
		ei_device_paused(device);
		queue_paused_event(device);
	}

	return 0;
}

int
ei_send_close_device(struct ei_device *device)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	int rc = ei_connection_request_close_device(ei->connection, device->id);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_start_emulating(struct ei_device *device, uint32_t sequence)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	int rc = ei_connection_request_start_emulating(ei->connection, device->id, sequence);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_stop_emulating(struct ei_device *device)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	int rc = ei_connection_request_stop_emulating(ei->connection, device->id);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_frame(struct ei_device *device, uint64_t time)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	if (!device->send_frame_event)
		return 0;

	device->send_frame_event = false;

	int rc = ei_connection_request_frame(ei->connection, device->id, us2ms(time), time % 1000);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_pointer_rel(struct ei_device *device, double x, double y)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_pointer_relative(ei->connection, device->id, x, y);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_pointer_abs(struct ei_device *device, double x, double y)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_pointer_absolute(ei->connection, device->id, x, y);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_pointer_button(struct ei_device *device, uint32_t button, bool is_press)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_pointer_button(ei->connection, device->id, button, is_press);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int ei_send_pointer_scroll(struct ei_device *device, double x, double y)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_pointer_scroll(ei->connection, device->id, x, y);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int ei_send_pointer_scroll_stop(struct ei_device *device, double x, double y)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_pointer_scroll_stop(ei->connection, device->id, x, y, false);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int ei_send_pointer_scroll_cancel(struct ei_device *device, double x, double y)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_pointer_scroll_stop(ei->connection, device->id, x, y, true);
	if (rc)
		ei_disconnect(ei);
	return rc;
}


int ei_send_pointer_scroll_discrete(struct ei_device *device, int32_t x, int32_t y)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_pointer_scroll_discrete(ei->connection, device->id, x, y);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_keyboard_key(struct ei_device *device, uint32_t key, bool is_press)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_keyboard_key(ei->connection, device->id, key, is_press);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_touch_down(struct ei_device *device, uint32_t tid,
		   double x, double y)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_touch_down(ei->connection, device->id, tid, x, y);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_touch_motion(struct ei_device *device, uint32_t tid,
		     double x, double y)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_touch_motion(ei->connection, device->id, tid, x, y);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

int
ei_send_touch_up(struct ei_device *device, uint32_t tid)
{
	struct ei *ei = ei_device_get_context(device);

	if (ei->state == EI_STATE_NEW || ei->state == EI_STATE_DISCONNECTED)
		return 0;

	device->send_frame_event = true;

	int rc = ei_connection_request_touch_up(ei->connection, device->id, tid);
	if (rc)
		ei_disconnect(ei);
	return rc;
}

_public_ struct ei_event*
ei_get_event(struct ei *ei)
{
	if (list_empty(&ei->event_queue))
		return NULL;

	struct ei_event *e = list_first_entry(&ei->event_queue, e, link);
	list_remove(&e->link);

	return e;
}

_public_ struct ei_event*
ei_peek_event(struct ei *ei)
{
	if (list_empty(&ei->event_queue))
		return NULL;

	struct ei_event *e = list_first_entry(&ei->event_queue, e, link);
	return ei_event_ref(e);
}

static int handle_msg_disconnected(struct ei_connection *connection, uint32_t reason, const char *explanation)
{
	struct ei *ei = ei_connection_get_context(connection);

	if (reason == EI_CONNECTION_DISCONNECT_REASON_DISCONNECTED)
		log_info(ei, "Disconnected by EIS");
	else
		log_info(ei, "Disconnected after error: %s", explanation);

	return -ECANCELED;
}

#define DISCONNECT_IF_SENDER_CONTEXT(ei_) do {\
	if (ei_->is_sender) { \
		log_bug_client(ei_, "Invalid event from receiver EIS context. Disconnecting"); \
		return -ECANCELED; \
	} \
} while(0)

static int
handle_msg_start_emulating(struct ei_connection *connection, uint32_t deviceid, uint32_t sequence)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		ei_device_event_start_emulating(device, sequence);

	return 0;
}

static int
handle_msg_stop_emulating(struct ei_connection *connection, uint32_t deviceid)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		ei_device_event_stop_emulating(device);

	return 0;
}

static int
handle_msg_frame(struct ei_connection *connection, uint32_t deviceid, uint32_t time, uint32_t micros)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_frame(device, ms2us(time) + micros);

	return 0;
}

static int
handle_msg_pointer_rel(struct ei_connection *connection, uint32_t deviceid, float x, float y)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_pointer_rel(device, x, y);

	return -EINVAL;
}

static int
handle_msg_pointer_abs(struct ei_connection *connection, uint32_t deviceid, float x, float y)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_pointer_abs(device, x, y);

	return -EINVAL;
}

static int
handle_msg_pointer_button(struct ei_connection *connection, uint32_t deviceid,
			  uint32_t button, uint32_t state)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_pointer_button(device, button, !!state);

	return -EINVAL;
}

static int
handle_msg_pointer_scroll(struct ei_connection *connection, uint32_t deviceid, float x, float y)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_pointer_scroll(device, x, y);

	return -EINVAL;
}

static int
handle_msg_pointer_scroll_discrete(struct ei_connection *connection, uint32_t deviceid,
				   int32_t x, int32_t y)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_pointer_scroll_discrete(device, x, y);

	return -EINVAL;
}

static int
handle_msg_pointer_scroll_stop(struct ei_connection *connection, uint32_t deviceid,
			       uint32_t x, uint32_t y, uint32_t is_cancel)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device) {
		if (is_cancel)
			return ei_device_event_pointer_scroll_cancel(device, !!x, !!y);
		else
			return ei_device_event_pointer_scroll_stop(device, !!x, !!y);
	}

	return -EINVAL;
}

static int
handle_msg_keyboard_key(struct ei_connection *connection, uint32_t deviceid,
			uint32_t key, uint32_t state)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_keyboard_key(device, key, !!state);

	return -EINVAL;
}

static int
handle_msg_touch_down(struct ei_connection *connection, uint32_t deviceid,
		      uint32_t touchid, float x, float y)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_touch_down(device, touchid, x, y);

	return -EINVAL;
}

static int
handle_msg_touch_motion(struct ei_connection *connection, uint32_t deviceid,
			uint32_t touchid, float x, float y)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_touch_motion(device, touchid, x, y);

	return -EINVAL;
}

static int
handle_msg_touch_up(struct ei_connection *connection, uint32_t deviceid, uint32_t touchid)
{
	struct ei *ei = ei_connection_get_context(connection);

	DISCONNECT_IF_SENDER_CONTEXT(ei);

	struct ei_device *device = ei_find_device(ei, deviceid);

	if (device)
		return ei_device_event_touch_up(device, touchid);

	return -EINVAL;
}

static void
connected(struct ei_connection *connection, void *user_data)
{
	struct ei *ei = ei_connection_get_context(connection);

	/* FIXME: the connected event *should* mean that the server
	 * has accepted us but we don't currently have any event
	 * for this to hook onto. So let's just assume "connected" means
	 * the server has seen our messages.
	 */
	ei->state = EI_STATE_CONNECTED;
	queue_connect_event(ei);
}

static int
handle_msg_connection_setup(struct ei_connection *connection, uint32_t new_id, uint32_t version)
{
	struct ei *ei = ei_connection_get_context(connection);

	struct ei_connection_setup *setup = ei_connection_setup_new(ei, new_id, version);
	if (version >= EI_CONNECTION_SETUP_REQUEST_TYPE_SINCE_VERSION)
		ei_connection_setup_request_type(setup, ei->is_sender ? EI_CONNECTION_SETUP_CONTEXT_TYPE_SENDER : EI_CONNECTION_SETUP_CONTEXT_TYPE_RECEIVER);
	if (version >= EI_CONNECTION_SETUP_REQUEST_NAME_SINCE_VERSION)
		ei_connection_setup_request_name(setup, ei->name);
	if (version >= EI_CONNECTION_SETUP_REQUEST_INTERFACE_SINCE_VERSION) {
		ei_connection_setup_request_interface(setup, "ei_connection", VERSION_V(1));
		ei_connection_setup_request_interface(setup, "ei_callback", VERSION_V(1));
		ei_connection_setup_request_interface(setup, "ei_seat", VERSION_V(1));
	}
	ei_connection_setup_request_done(setup);
	ei_connection_setup_unref(setup);

	ei->state = EI_STATE_CONNECTING;

	ei_connection_sync(ei->connection, connected, NULL);

	return 0;
}

static const struct ei_connection_interface intf_state_backend = {
	.connection_setup = handle_msg_connection_setup,
	/* Everything triggers -EPROTO */
};

static const struct ei_connection_interface intf_state_connecting = {
	.connection_setup = handle_msg_connection_setup,
	.disconnected = handle_msg_disconnected,
};

static const struct ei_connection_interface intf_state_connected = {
	.connection_setup = NULL, /* EPROTO */
	.disconnected = handle_msg_disconnected,
	.seat = handle_msg_seat,
	.device_added = handle_msg_device_added,
	.device_removed = handle_msg_device_removed,
	.device_resumed = handle_msg_device_resumed,
	.device_paused = handle_msg_device_paused,
	.device_region = handle_msg_device_region,
	.device_keymap = handle_msg_device_keymap,
	.device_done = handle_msg_device_added_done,
	.keyboard_modifiers = handle_msg_keyboard_modifiers,

	/* events */
	.start_emulating = handle_msg_start_emulating,
	.stop_emulating = handle_msg_stop_emulating,
	.pointer_relative = handle_msg_pointer_rel,
	.pointer_absolute = handle_msg_pointer_abs,
	.pointer_button = handle_msg_pointer_button,
	.pointer_scroll = handle_msg_pointer_scroll,
	.pointer_scroll_stop = handle_msg_pointer_scroll_stop,
	.pointer_scroll_discrete = handle_msg_pointer_scroll_discrete,
	.keyboard_key = handle_msg_keyboard_key,
	.touch_down = handle_msg_touch_down,
	.touch_motion = handle_msg_touch_motion,
	.touch_up = handle_msg_touch_up,
	.frame = handle_msg_frame,
};

static const struct ei_connection_interface *interfaces[] = {
	[EI_STATE_NEW] = NULL,
	[EI_STATE_BACKEND] = &intf_state_backend,
	[EI_STATE_CONNECTING] = &intf_state_connecting,
	[EI_STATE_CONNECTED] = &intf_state_connected,
	[EI_STATE_DISCONNECTING] = NULL,
	[EI_STATE_DISCONNECTED] = NULL,
};


const struct ei_connection_interface *
ei_get_interface(struct ei *ei)
{
	assert(ei->state < ARRAY_LENGTH(interfaces));
	return interfaces[ei->state];
}

static int
lookup_object(uint32_t object_id, struct brei_object **object, void *userdata)
{
	struct ei *ei = userdata;

	struct brei_object *obj;
	list_for_each(obj, &ei->proto_objects, link) {
		if (obj->id == object_id) {
			*object = obj;
			return 0;
		}
	}

	return -ENOENT;
}

static void
connection_dispatch(struct source *source, void *userdata)
{
	struct ei *ei = userdata;
	enum ei_state old_state = ei->state;

	int rc = brei_dispatch(source_get_fd(source), lookup_object, ei);
	if (rc < 0) {
		brei_drain_fd(source_get_fd(source));
		ei_disconnect(ei);
	}

	static const char *states[] = {
		"NEW",
		"BACKEND",
		"CONNECTING",
		"CONNECTED",
		"DISCONNECTED",
		"DISCONNECTING",
	};
	if (rc == -ECANCELED)
		log_info(ei, "Disconnected");
	else if (rc)
		log_warn(ei, "Connection error: %s", strerror(-rc));

	if (old_state != ei->state)
		log_debug(ei, "Connection dispatch: %s -> %s",
			  states[old_state],
			  states[ei->state]);
}

int
ei_send_message(struct ei *ei, const struct brei_object *object,
		uint32_t opcode, const char *signature, size_t nargs, ...)
{
	int fd = source_get_fd(ei->source);

	log_debug(ei, "sending: object %#x (%s@v%u:%s(%u)) signature '%s'",
	   object->id,
	   object->interface->name,
	   object->interface->version,
	   object->interface->requests[opcode].name,
	   opcode,
	   signature);

	va_list args;
	va_start(args, nargs);
	int rc = brei_send_message(fd, object->id, opcode, signature, nargs, args);
	va_end(args);
	return rc < 0 ? rc : 0;
}

int
ei_set_socket(struct ei *ei, int fd)
{
	struct source *source = source_new(fd, connection_dispatch, ei);
	int rc = sink_add_source(ei->sink, source);
	if (rc == 0) {
		ei->source = source_ref(source);
		ei->state = EI_STATE_BACKEND;

		/* The server SHOULD have already sent the connection setup, let's
		 * process that. If not ready, it'll happen in the next dispatch.
		 *
		 * FIXME: this will block if O_NONBLOCK is missing
		 */
		ei_dispatch(ei);
	}

	source_unref(source);

	return rc < 0 ? rc : 0;
}

void
ei_add_seat(struct ei_seat *seat)
{
	queue_seat_added_event(seat);
}

_public_ void
ei_configure_name(struct ei *ei, const char *name)
{
	if (ei->state != EI_STATE_NEW) {
		log_bug_client(ei,"Client is already connected");
		return;
	}

	if (strlen(name) > 1024) {
		log_bug_client(ei, "Client name too long");
		return;
	}

	free(ei->name);
	ei->name = xstrdup(name);
}

_public_ uint64_t
ei_now(struct ei *ei)
{
	uint64_t ts = 0;
	int rc = now(&ts);

	if (rc < 0) {
		/* We should probably disconnect here but the chances of this
		 * happening are so slim it's not worth worrying about. Plus,
		 * if this fails we're likely to be inside eis_device_frame()
		 * so we should flush a frame event before disconnecting and... */
		log_error(ei, "clock_gettime failed: %s", strerror(-rc));
	}
	return ts;
}

#ifdef _enable_tests_
#include "util-munit.h"

MUNIT_TEST(test_init_unref)
{
	struct ei *ei = ei_new(NULL);

	munit_assert_int(ei->state, ==, EI_STATE_NEW);
	munit_assert(list_empty(&ei->event_queue));
	munit_assert(list_empty(&ei->seats));

	munit_assert_not_null(ei->sink);

	struct ei *refd = ei_ref(ei);
	munit_assert_ptr_equal(ei, refd);
	munit_assert_int(ei->object.refcount, ==, 2);

	struct ei *unrefd = ei_unref(ei);
	munit_assert_null(unrefd);

	unrefd = ei_unref(ei);
	munit_assert_null(unrefd);

	return MUNIT_OK;
}

MUNIT_TEST(test_configure_name)
{
	struct ei *ei = ei_new(NULL);

	ei_configure_name(ei, "foo");
	munit_assert_string_equal(ei->name, "foo");
	ei_configure_name(ei, "bar");
	munit_assert_string_equal(ei->name, "bar");

	/* ignore names that are too long */
	char buf[1200] = {0};
	memset(buf, 'a', sizeof(buf) - 1);
	ei_configure_name(ei, buf);
	munit_assert_string_equal(ei->name, "bar");

	/* ignore names in all other states */
	for (enum ei_state state = EI_STATE_NEW + 1;
	     state <= EI_STATE_DISCONNECTED;
	     state++) {
		ei->state = state;
		ei_configure_name(ei, "expect ignored");
		munit_assert_string_equal(ei->name, "bar");
	}

	ei_unref(ei);

	return MUNIT_OK;
}
#endif