#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <libudev.h>
#include <unistd.h>
#include <string.h>
#include <systemd/sd-bus.h>
#include <errno.h>

#include "utils.h"
#include "rcm-server.h"
#include "rcm-server-keymap.h"

static int
method_echostring(sd_bus_message *m, void *userdata, sd_bus_error *error)
{
	const char *msg;
	int r;

	r = sd_bus_message_read(m, "s", &msg);
	if (r < 0) {
		fprintf(stderr, "Failed to parse parameters: %s\n", strerror(-r));
		return sd_bus_error_set_errno(error, r);
	}

	return sd_bus_reply_method_return(m, "s", msg);
}

static struct device *
find_device_by_path(struct manager *mgr, const char *path)
{
	struct device *dev;

	list_for_each_entry(dev, &mgr->devices, list)
		if (!strcmp(dev->path, path))
			return dev;

	return NULL;
}

static int
property_get_driver_name(sd_bus *bus, const char *path, const char *interface,
			 const char *property, sd_bus_message *reply, void *userdata,
			 sd_bus_error *error)
{
	struct manager *mgr = userdata;
	struct device *dev;

	dev = find_device_by_path(mgr, path);
	if (!dev) {
		sd_bus_error_set_const(error, "org.gnome.RemoteControlManager.InvalidDevice", "Sorry, invalid device");
		return -EINVAL;
	}

	if (!strcmp(property, "DriverName"))
		return sd_bus_message_append(reply, "s", dev->driver_name);
	else if (!strcmp(property, "KernelKeymapName"))
		return sd_bus_message_append(reply, "s", dev->keymap_name);

	sd_bus_error_set_const(error, "org.gnome.RemoteControlManager.InvalidProperty", "Sorry, invalid property");
	return -EINVAL;
}


static int
method_listkeymaps(sd_bus_message *m, void *userdata, sd_bus_error *error)
{
	_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
	struct manager *mgr = userdata;
	struct device *dev;
	struct keymap *keymap;
	int r;

	dev = find_device_by_path(mgr, sd_bus_message_get_path(m));
	if (!dev) {
		sd_bus_error_set_const(error, "org.gnome.RemoteControlManager.InvalidDevice", "Sorry, invalid device");
		return -EINVAL;
	}

	r = sd_bus_message_new_method_return(m, &reply);
	if (r < 0)
		goto out;

	r = sd_bus_message_open_container(reply, 'a', "s");
	if (r < 0)
		goto out;

	list_for_each_entry(keymap, &dev->keymaps, list) {
		printf("Listing keymaps for %s: %s\n", dev->name, keymap->name);
		r = sd_bus_message_append(reply, "s", keymap->name);
		if (r < 0)
			goto out;
	}

	r = sd_bus_message_close_container(reply);
	if (r < 0)
		goto out;

	r = sd_bus_send(NULL, reply, NULL);
	if (r < 0)
		goto out;

	return 1;

out:
	return sd_bus_error_set_errno(error, r);
}

static int
method_getkeymap(sd_bus_message *m, void *userdata, sd_bus_error *error)
{
	_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
	struct manager *mgr = userdata;
	struct device *dev;
	struct keymap *keymap;
	const char *name;
	int r;
	unsigned i;

	dev = find_device_by_path(mgr, sd_bus_message_get_path(m));
	if (!dev) {
		sd_bus_error_set_const(error, "org.gnome.RemoteControlManager.InvalidDevice", "Sorry, invalid device");
		return -EINVAL;
	}

	r = sd_bus_message_read(m, "s", &name);
	if (r < 0) {
		fprintf(stderr, "Failed to parse parameters: %s\n", strerror(-r));
		return r;
	}

	keymap = find_keymap_by_name(dev, name);
	if (!keymap) {
		sd_bus_error_set_const(error, "org.gnome.RemoteControlManager.InvalidKeymap", "Sorry, unknown keymap");
		return -EINVAL;
	}

	r = sd_bus_message_new_method_return(m, &reply);
	if (r < 0)
		goto out;

	r = sd_bus_message_append(reply, "q", keymap->cols);
	if (r < 0)
		goto out;

	r = sd_bus_message_append(reply, "q", keymap->rows);
	if (r < 0)
		goto out;

	r = sd_bus_message_open_container(reply, 'a', "a{sv}");
	if (r < 0)
		goto out;

	for (i = 0; i < (keymap->rows * keymap->cols); i++) {
		r = sd_bus_message_append(reply, "a{sv}", 2,
					  "name", "s", keymap->layout[i]->name,
					  "keycode", "s", keymap->layout[i]->value);
		if (r < 0)
			goto out;
	}

	r = sd_bus_message_close_container(reply);
	if (r < 0)
		goto out;

	r = sd_bus_send(NULL, reply, NULL);
	if (r < 0)
		goto out;

	return 1;

out:
	return sd_bus_error_set_errno(error, r);
}

static const sd_bus_vtable device_vtable[] = {
	SD_BUS_VTABLE_START(0),
	SD_BUS_PROPERTY("DriverName", "s", property_get_driver_name, 0, 0),
	SD_BUS_PROPERTY("KernelKeymapName", "s", property_get_driver_name, 0, 0),
	SD_BUS_METHOD("EchoString", "s", "s", method_echostring, SD_BUS_VTABLE_UNPRIVILEGED),
	SD_BUS_METHOD("ListKeymaps", NULL, "as", method_listkeymaps, SD_BUS_VTABLE_UNPRIVILEGED),
	SD_BUS_METHOD("GetKeymap", "s", "qqaa{sv}", method_getkeymap, SD_BUS_VTABLE_UNPRIVILEGED),
	SD_BUS_VTABLE_END
};

static int
my_bus_emit_object_changed(sd_bus *bus, const char *path, bool added)
{
	int r;
	_cleanup_bus_message_unref_ sd_bus_message *m = NULL;

	printf("Sending signal %s for path %s\n",
	       added ? "InterfacesAdded" : "InterfacesRemoved",
	       path);

	r = sd_bus_message_new_signal(bus, &m, "/org/gnome/RemoteControlManager",
				      "org.freedesktop.DBus.ObjectManager",
				      added ? "InterfacesAdded" : "InterfacesRemoved");
	if (r < 0)
		return r;

	r = sd_bus_message_append_basic(m, 'o', path);
	if (r < 0)
		return r;

	if (added) {
		r = sd_bus_message_open_container(m, 'a', "{sa{sv}}");
		if (r < 0)
			return r;

		r = sd_bus_message_append(m, "{sa{sv}}", "org.gnome.RemoteControlManager.Device", 0);
		if (r < 0)
			return r;
	} else {
		r = sd_bus_message_open_container(m, 'a', "s");
		if (r < 0)
			return r;

		r = sd_bus_message_append(m, "s", "org.gnome.RemoteControlManager.Device");
		if (r < 0)
			return r;
	}

	r = sd_bus_message_close_container(m);
	if (r < 0)
		return r;

	r = sd_bus_send(bus, m, NULL);
	return r;
}

static void
remove_device(struct manager *mgr, struct udev_device *udev)
{
	const char *name;
	struct device *device;

	name = udev_device_get_sysname(udev);
	printf("Asked to remove device %s\n", name);

	list_for_each_entry(device, &mgr->devices, list) {
		if (strcmp(device->name, name))
			continue;
		list_del(&device->list);
		my_bus_emit_object_changed(mgr->bus, device->path, false);
		mgr->num_devices--;
		break;
	}
}

static void
add_device(struct manager *mgr, struct udev_device *udev)
{
	const char *name;
	const char *str;
	char *path;
	struct device *device;

	name = udev_device_get_sysname(udev);
	if (asprintf(&path, "/org/gnome/RemoteControlManager/%s", name) < 0) {
		fprintf(stderr, "asprintf failed: %m\n");
		return;
	}

	device = malloc(sizeof(*device));
	if (!device) {
		fprintf(stderr, "malloc failed: %m\n");
		free(path);
		return;
	}

	list_init(&device->keymaps);
	device->path = path;
	device->name = device->path + strlen("/org/gnome/RemoteControlManager/");

	if (keymaps_load(device) < 0) {
		fprintf(stderr, "failed to load keymaps: %m\n");
		free(path);
		free(device);
	}

	str = udev_device_get_sysattr_value(udev, "uevent");
	if (str) {
		char tmp[strlen(str) + 1];
		char *token;

		strcpy(tmp, str);

		for (token = strtok(tmp, "\n"); token; token = strtok(NULL, "\n")) {
			if (!strncmp(token, "DRV_NAME=", strlen("DRV_NAME=")))
				device->driver_name = strdup(token + strlen("DRV_NAME="));
			else if (!strncmp(token, "NAME=", strlen("NAME=")))
				device->keymap_name = strdup(token + strlen("NAME="));
			else
				printf("Unused uevent: %s\n", token);
		}
	}

	printf("Adding Device Object\n");
	printf("   Path      : %s\n", udev_device_get_syspath(udev));
	printf("   Node      : %s\n", udev_device_get_devnode(udev));
	printf("   Subsystem : %s\n", udev_device_get_subsystem(udev));
	printf("   Devtype   : %s\n", udev_device_get_devtype(udev));
	printf("   Action    : %s\n", udev_device_get_action(udev));
	printf("   Protocols : %s\n",
	       udev_device_get_sysattr_value(udev, "protocols"));
	printf("   Uevent    : %s\n",
	       udev_device_get_sysattr_value(udev, "uevent"));

	list_add(&device->list, &mgr->devices);
	mgr->num_devices++;

	my_bus_emit_object_changed(mgr->bus, path, true);
}

static int
udev_read(sd_event_source *s, int fd, uint32_t revents, void *userdata)
{
	struct manager *mgr = userdata;
	struct udev_device *dev;

	if (revents & EPOLLHUP) {
		fprintf(stderr, "udev connection closed!\n");
		return 0;
	}

	if (!(revents & EPOLLIN)) {
		fprintf(stderr, "unexpected udev event: %" PRIu32 "\n", revents);
		return 0;
	}

	while ((dev = udev_monitor_receive_device(mgr->udev_mon))) {
		printf("Read device: %s\n", udev_device_get_syspath(dev));
		if (!strcmp(udev_device_get_action(dev), "add"))
			add_device(mgr, dev);
		else if (!strcmp(udev_device_get_action(dev), "remove"))
			remove_device(mgr, dev);
		udev_device_unref(dev);
	}

	return 1;
}

static int
udev_setup(struct manager *mgr)
{
	struct udev_enumerate *enumerate;
	struct udev_list_entry *devices, *dev_list_entry;
	struct udev_device *dev;

	mgr->udev = udev_new();
	if (!mgr->udev)
		return -ENOMEM;

	mgr->udev_mon = udev_monitor_new_from_netlink(mgr->udev, "udev");
	udev_monitor_filter_add_match_subsystem_devtype(mgr->udev_mon, "rc", NULL);
	udev_monitor_enable_receiving(mgr->udev_mon);

	enumerate = udev_enumerate_new(mgr->udev);
	udev_enumerate_add_match_subsystem(enumerate, "rc");
	udev_enumerate_scan_devices(enumerate);
	devices = udev_enumerate_get_list_entry(enumerate);

	udev_list_entry_foreach(dev_list_entry, devices) {
		const char *path;

		path = udev_list_entry_get_name(dev_list_entry);
		if (!path) {
			printf("Failed to get udev name\n");
			continue;
		}

		dev = udev_device_new_from_syspath(mgr->udev, path);
		if (!dev) {
			printf("Failed to create udev device\n");
			continue;
		}

		add_device(mgr, dev);

		udev_device_unref(dev);
	}
	udev_enumerate_unref(enumerate);

	return sd_event_add_io(mgr->event, &mgr->udev_ev,
			       udev_monitor_get_fd(mgr->udev_mon),
			       EPOLLIN, udev_read, mgr);
}

static int
enumerator(sd_bus *bus, const char *path, void *userdata, char ***retnodes, sd_bus_error *error)
{
	_cleanup_strv_free_ char **nodes = NULL;
	struct manager *mgr = userdata;
	struct device *device;
	int i = 0;

	if (!path)
		return 0;

	nodes = zmalloc((mgr->num_devices + 1) * sizeof(char *));
	if (!nodes)
		return -ENOMEM;

	list_for_each_entry(device, &mgr->devices, list) {
		nodes[i] = strdup(device->path);
		if (!nodes[i])
			return -ENOMEM;
		i++;
	}

	nodes[i++] = NULL;
	*retnodes = nodes;
	nodes = NULL;

	return 1;
}

static void
free_manager(struct manager *mgr) {
	if (!mgr)
		return;

	sd_event_source_unref(mgr->udev_ev);
	sd_bus_detach_event(mgr->bus);
	sd_event_unref(mgr->event);
	udev_monitor_unref(mgr->udev_mon);
	udev_unref(mgr->udev);

	while (!list_empty(&mgr->devices)) {
		struct device *dev = list_first_entry(&mgr->devices, typeof(*dev), list);
		list_del(&dev->list);
		free(dev->path);
		free(dev->driver_name);
		free(dev->keymap_name);

		while (!list_empty(&dev->keymaps)) {
			struct keymap *keymap = list_first_entry(&dev->keymaps, typeof(*keymap), list);
			list_del(&keymap->list);
			free(keymap->name);
			free(keymap);
		}

		free(dev);
	}
	free(mgr);
}

static int
block_signals(void)
{
	sigset_t sigset;
	int r;

	r = sigemptyset(&sigset);
	if (r < 0)
		return r;

	r = sigaddset(&sigset, SIGINT);
	if (r < 0)
		return r;

	r = sigaddset(&sigset, SIGTERM);
	if (r < 0)
		return r;

	return sigprocmask(SIG_BLOCK, &sigset, NULL);
}

int
main(int argc, char **argv)
{
	int r;
	struct manager *mgr;
	_cleanup_bus_close_unref_ sd_bus *bus = NULL;
	_cleanup_bus_slot_unref_ struct sd_bus_slot *vtable_slot = NULL;
	_cleanup_bus_slot_unref_ struct sd_bus_slot *enumerator_slot = NULL;
	_cleanup_bus_slot_unref_ struct sd_bus_slot *objm_slot = NULL;
	_cleanup_event_source_unref_ sd_event_source *sigint_ev = NULL;
	_cleanup_event_source_unref_ sd_event_source *sigterm_ev = NULL;

	mgr = zmalloc(sizeof(*mgr));
	if (!mgr) {
		fprintf(stderr, "Failed to allocate memory: %m\n");
		goto finish;
	}
	list_init(&mgr->devices);

	r = sd_bus_open_user(&bus);
	if (r < 0) {
		fprintf(stderr, "Failed to connect to system bus: %s\n", strerror(-r));
		goto finish;
	}
	mgr->bus = bus;

	r = sd_bus_request_name(mgr->bus, "org.gnome.RemoteControlManager", 0);
	if (r < 0) {
		fprintf(stderr, "Failed to acquire service name: %s\n", strerror(-r));
		goto finish;
	}

	r = sd_bus_add_fallback_vtable(mgr->bus, &vtable_slot, "/org/gnome/RemoteControlManager",
				       "org.gnome.RemoteControlManager.Device",
				       device_vtable, NULL, mgr);
	if (r < 0) {
		fprintf(stderr, "Failed to add vtable: %s\n", strerror(-r));
		goto finish;
	}

	r = sd_bus_add_node_enumerator(mgr->bus, &enumerator_slot, "/org/gnome/RemoteControlManager", enumerator, mgr);
	if (r < 0) {
		fprintf(stderr, "Failed to create node enumerator: %s\n", strerror(-r));
		goto finish;
	}

	r = sd_bus_add_object_manager(mgr->bus, &objm_slot, "/org/gnome/RemoteControlManager");
	if (r < 0) {
		fprintf(stderr, "Failed to create object manager: %s\n", strerror(-r));
		goto finish;
	}

	r = sd_event_default(&mgr->event);
	if (r < 0) {
		fprintf(stderr, "Failed to create sd_event: %s\n", strerror(-r));
		goto finish;
	}

	r = sd_bus_attach_event(mgr->bus, mgr->event, 0);
	if (r < 0) {
		fprintf(stderr, "Failed to attach bus to event loop: %s\n", strerror(-r));
		goto finish;
	}

	r = udev_setup(mgr);
	if (r < 0) {
		fprintf(stderr, "Failed to setup udev monitoring: %s\n", strerror(-r));
		goto finish;
	}

	r = block_signals();
	if (r < 0) {
		fprintf(stderr, "Failed to block signals: %m\n");
		goto finish;
	}

	sd_event_add_signal(mgr->event, &sigint_ev, SIGINT, NULL, NULL);
	sd_event_add_signal(mgr->event, &sigterm_ev, SIGTERM, NULL, NULL);

	r = sd_event_loop(mgr->event);
	if (r < 0) {
		fprintf(stderr, "Event loop failed: %s\n", strerror(-r));
		goto finish;
	}

	sd_event_get_exit_code(mgr->event, &r);

finish:
	free_manager(mgr);

	return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}