/*
 * Copyright © 2013 Intel Corporation
 * Copyright © 2013-2015 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 <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "evdev.h"
#include "udev-seat.h"

static const char default_seat[] = "seat0";
static const char default_seat_name[] = "default";

static struct udev_seat *
udev_seat_create(struct udev_input *input,
		 const char *device_seat,
		 const char *seat_name);
static struct udev_seat *
udev_seat_get_named(struct udev_input *input, const char *seat_name);


static inline bool
filter_duplicates(struct udev_seat *udev_seat,
		  struct udev_device *udev_device)
{
	struct libinput_device *device;
	const char *new_syspath = udev_device_get_syspath(udev_device);
	bool ignore_device = false;

	if (!udev_seat)
		return false;

	list_for_each(device, &udev_seat->base.devices_list, link) {
		const char *syspath;
		struct udev_device *ud;

		ud = libinput_device_get_udev_device(device);
		if (!ud)
			continue;

		syspath = udev_device_get_syspath(ud);
		if (syspath && new_syspath && streq(syspath, new_syspath))
			ignore_device = true;
		udev_device_unref(ud);

		if (ignore_device)
			break;
	}

	return ignore_device;
}

static int
device_added(struct udev_device *udev_device,
	     struct udev_input *input,
	     const char *seat_name)
{
	struct evdev_device *device;
	const char *devnode, *sysname;
	const char *device_seat, *output_name;
	struct udev_seat *seat;

	device_seat = udev_device_get_property_value(udev_device, "ID_SEAT");
	if (!device_seat)
		device_seat = default_seat;

	if (!streq(device_seat, input->seat_id))
		return 0;

	if (ignore_litest_test_suite_device(udev_device))
		return 0;

	devnode = udev_device_get_devnode(udev_device);
	sysname = udev_device_get_sysname(udev_device);

	/* Search for matching logical seat */
	if (!seat_name)
		seat_name = udev_device_get_property_value(udev_device, "WL_SEAT");
	if (!seat_name)
		seat_name = default_seat_name;

	seat = udev_seat_get_named(input, seat_name);

	/* There is a race at startup: a device added between setting
	 * up the udev monitor and enumerating all current devices may show
	 * up in both lists. Filter those out.
	 */
	if (filter_duplicates(seat, udev_device))
		return 0;

	if (seat)
		libinput_seat_ref(&seat->base);
	else {
		seat = udev_seat_create(input, device_seat, seat_name);
		if (!seat)
			return -1;
	}

	device = evdev_device_create(&seat->base, udev_device);
	libinput_seat_unref(&seat->base);

	if (device == EVDEV_UNHANDLED_DEVICE) {
		log_info(&input->base,
			 "%-7s - not using input device '%s'\n",
			 sysname,
			 devnode);
		return 0;
	}

	if (device == NULL) {
		log_info(&input->base,
			 "%-7s - failed to create input device '%s'\n",
			 sysname,
			 devnode);
		return 0;
	}

	evdev_read_calibration_prop(device);

	output_name = udev_device_get_property_value(udev_device, "WL_OUTPUT");
	device->output_name = safe_strdup(output_name);

	return 0;
}

static void
device_removed(struct udev_device *udev_device, struct udev_input *input)
{
	struct evdev_device *device;
	struct udev_seat *seat;
	const char *syspath;

	syspath = udev_device_get_syspath(udev_device);
	list_for_each(seat, &input->base.seat_list, base.link) {
		list_for_each_safe(device,
				   &seat->base.devices_list, base.link) {
			if (streq(syspath,
				  udev_device_get_syspath(device->udev_device))) {
				evdev_device_remove(device);
				break;
			}
		}
	}
}

static int
udev_input_add_devices(struct udev_input *input, struct udev *udev)
{
	struct udev_enumerate *e;
	struct udev_list_entry *entry;
	struct udev_device *device;
	const char *path, *sysname;

	e = udev_enumerate_new(udev);
	udev_enumerate_add_match_subsystem(e, "input");
	udev_enumerate_scan_devices(e);
	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
		path = udev_list_entry_get_name(entry);
		device = udev_device_new_from_syspath(udev, path);
		if (!device)
			continue;

		sysname = udev_device_get_sysname(device);
		if (!strneq("event", sysname, 5)) {
			udev_device_unref(device);
			continue;
		}

		/* Skip unconfigured device. udev will send an event
		 * when device is fully configured  */
		if (!udev_device_get_is_initialized(device)) {
			log_debug(&input->base,
				  "%-7s - skip unconfigured input device '%s'\n",
				  sysname,
				  udev_device_get_devnode(device));
			udev_device_unref(device);
			continue;
		}

		if (device_added(device, input, NULL) < 0) {
			udev_device_unref(device);
			udev_enumerate_unref(e);
			return -1;
		}

		udev_device_unref(device);
	}
	udev_enumerate_unref(e);

	return 0;
}

static void
evdev_udev_handler(void *data)
{
	struct udev_input *input = data;
	struct udev_device *udev_device;
	const char *action;

	udev_device = udev_monitor_receive_device(input->udev_monitor);
	if (!udev_device)
		return;

	action = udev_device_get_action(udev_device);
	if (!action)
		goto out;

	if (!strneq("event", udev_device_get_sysname(udev_device), 5))
		goto out;

	if (streq(action, "add"))
		device_added(udev_device, input, NULL);
	else if (streq(action, "remove"))
		device_removed(udev_device, input);

out:
	udev_device_unref(udev_device);
}

static void
udev_input_remove_devices(struct udev_input *input)
{
	struct evdev_device *device;
	struct udev_seat *seat;

	list_for_each_safe(seat, &input->base.seat_list, base.link) {
		libinput_seat_ref(&seat->base);
		list_for_each_safe(device,
				   &seat->base.devices_list, base.link) {
			evdev_device_remove(device);
		}
		libinput_seat_unref(&seat->base);
	}
}

static void
udev_input_disable(struct libinput *libinput)
{
	struct udev_input *input = (struct udev_input*)libinput;

	if (!input->udev_monitor)
		return;

	udev_monitor_unref(input->udev_monitor);
	input->udev_monitor = NULL;
	libinput_remove_source(&input->base, input->udev_monitor_source);
	input->udev_monitor_source = NULL;

	udev_input_remove_devices(input);
}

static int
udev_input_enable(struct libinput *libinput)
{
	struct udev_input *input = (struct udev_input*)libinput;
	struct udev *udev = input->udev;
	int fd;

	if (input->udev_monitor || !input->seat_id)
		return 0;

	input->udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
	if (!input->udev_monitor) {
		log_info(libinput,
			 "udev: failed to create the udev monitor\n");
		return -1;
	}

	if (udev_monitor_filter_add_match_subsystem_devtype(
				input->udev_monitor, "input", NULL)) {
		log_info(libinput, "udev: failed to set up filter\n");
		return -1;
	}

	if (udev_monitor_enable_receiving(input->udev_monitor)) {
		log_info(libinput, "udev: failed to bind the udev monitor\n");
		udev_monitor_unref(input->udev_monitor);
		input->udev_monitor = NULL;
		return -1;
	}

	fd = udev_monitor_get_fd(input->udev_monitor);
	input->udev_monitor_source = libinput_add_fd(&input->base,
						     fd,
						     evdev_udev_handler,
						     input);
	if (!input->udev_monitor_source) {
		udev_monitor_unref(input->udev_monitor);
		input->udev_monitor = NULL;
		return -1;
	}

	if (udev_input_add_devices(input, udev) < 0) {
		udev_input_disable(libinput);
		return -1;
	}

	return 0;
}

static void
udev_input_destroy(struct libinput *input)
{
	struct udev_input *udev_input = (struct udev_input*)input;

	if (input == NULL)
		return;

	udev_unref(udev_input->udev);
	free(udev_input->seat_id);
}

static void
udev_seat_destroy(struct libinput_seat *seat)
{
	struct udev_seat *useat = (struct udev_seat*)seat;
	free(useat);
}

static struct udev_seat *
udev_seat_create(struct udev_input *input,
		 const char *device_seat,
		 const char *seat_name)
{
	struct udev_seat *seat;

	seat = zalloc(sizeof *seat);

	libinput_seat_init(&seat->base, &input->base,
			   device_seat, seat_name,
			   udev_seat_destroy);

	return seat;
}

static struct udev_seat *
udev_seat_get_named(struct udev_input *input, const char *seat_name)
{
	struct udev_seat *seat;

	list_for_each(seat, &input->base.seat_list, base.link) {
		if (streq(seat->base.logical_name, seat_name))
			return seat;
	}

	return NULL;
}

static int
udev_device_change_seat(struct libinput_device *device,
			const char *seat_name)
{
	struct libinput *libinput = device->seat->libinput;
	struct udev_input *input = (struct udev_input *)libinput;
	struct evdev_device *evdev = evdev_device(device);
	struct udev_device *udev_device = evdev->udev_device;
	int rc;

	udev_device_ref(udev_device);
	device_removed(udev_device, input);
	rc = device_added(udev_device, input, seat_name);
	udev_device_unref(udev_device);

	return rc;
}

static const struct libinput_interface_backend interface_backend = {
	.resume = udev_input_enable,
	.suspend = udev_input_disable,
	.destroy = udev_input_destroy,
	.device_change_seat = udev_device_change_seat,
};

LIBINPUT_EXPORT struct libinput *
libinput_udev_create_context(const struct libinput_interface *interface,
			     void *user_data,
			     struct udev *udev)
{
	struct udev_input *input;

	if (!interface || !udev)
		return NULL;

	input = zalloc(sizeof *input);

	if (libinput_init(&input->base, interface,
			  &interface_backend, user_data) != 0) {
		libinput_unref(&input->base);
		free(input);
		return NULL;
	}

	input->udev = udev_ref(udev);

	return &input->base;
}

LIBINPUT_EXPORT int
libinput_udev_assign_seat(struct libinput *libinput,
			  const char *seat_id)
{
	struct udev_input *input = (struct udev_input*)libinput;

	if (!seat_id)
		return -1;

	if (strlen(seat_id) > 256) {
		log_bug_client(libinput,
			       "Unexpected seat id, limited to 256 characters.\n");
		return -1;
	}

	if (libinput->interface_backend != &interface_backend) {
		log_bug_client(libinput, "Mismatching backends.\n");
		return -1;
	}

	if (input->seat_id != NULL)
		return -1;

	/* We cannot do this during udev_create_context because the log
	 * handler isn't set up there but we really want to log to the right
	 * place if the quirks run into parser errors. So we have to do it
	 * here since we can expect the log handler to be set up by now.
	 */
	libinput_init_quirks(libinput);

	input->seat_id = safe_strdup(seat_id);

	if (udev_input_enable(&input->base) < 0)
		return -1;

	return 0;
}