/*
 *
 *  BlueZ - Bluetooth protocol stack for Linux
 *
 *  Copyright (C) 2009  Bastien Nocera <hadess@hadess.net>
 *  Copyright (C) 2011  Antonio Ospite <ospite@studenti.unina.it>
 *  Copyright (C) 2013  Szymon Janc <szymon.janc@gmail.com>
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stddef.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <linux/hidraw.h>
#include <linux/input.h>
#include <glib.h>
#include <libudev.h>

#include "lib/bluetooth.h"
#include "lib/uuid.h"
#include "src/adapter.h"
#include "src/device.h"
#include "src/plugin.h"
#include "src/log.h"
#include "src/shared/util.h"

static const struct {
	const char *name;
	uint16_t source;
	uint16_t vid;
	uint16_t pid;
	uint16_t version;
} devices[] = {
	{
		.name = "PLAYSTATION(R)3 Controller",
		.source = 0x0002,
		.vid = 0x054c,
		.pid = 0x0268,
		.version = 0x0000,
	},
};

struct leds_data {
	char *syspath_prefix;
	uint8_t bitmap;
};

static void leds_data_destroy(struct leds_data *data)
{
	free(data->syspath_prefix);
	free(data);
}

static struct udev *ctx = NULL;
static struct udev_monitor *monitor = NULL;
static guint watch_id = 0;

static int get_device_bdaddr(int fd, bdaddr_t *bdaddr)
{
	uint8_t buf[18];
	int ret;

	memset(buf, 0, sizeof(buf));

	buf[0] = 0xf2;

	ret = ioctl(fd, HIDIOCGFEATURE(sizeof(buf)), buf);
	if (ret < 0) {
		error("sixaxis: failed to read device address (%s)",
							strerror(errno));
		return ret;
	}

	baswap(bdaddr, (bdaddr_t *) (buf + 4));

	return 0;
}

static int get_master_bdaddr(int fd, bdaddr_t *bdaddr)
{
	uint8_t buf[8];
	int ret;

	memset(buf, 0, sizeof(buf));

	buf[0] = 0xf5;

	ret = ioctl(fd, HIDIOCGFEATURE(sizeof(buf)), buf);
	if (ret < 0) {
		error("sixaxis: failed to read master address (%s)",
							strerror(errno));
		return ret;
	}

	baswap(bdaddr, (bdaddr_t *) (buf + 2));

	return 0;
}

static int set_master_bdaddr(int fd, const bdaddr_t *bdaddr)
{
	uint8_t buf[8];
	int ret;

	buf[0] = 0xf5;
	buf[1] = 0x01;

	baswap((bdaddr_t *) (buf + 2), bdaddr);

	ret = ioctl(fd, HIDIOCSFEATURE(sizeof(buf)), buf);
	if (ret < 0)
		error("sixaxis: failed to write master address (%s)",
							strerror(errno));

	return ret;
}

static uint8_t calc_leds_bitmap(int number)
{
	uint8_t bitmap = 0;

	/* TODO we could support up to 10 (1 + 2 + 3 + 4) */
	if (number > 7)
		return bitmap;

	if (number > 4) {
		bitmap |= 0x10;
		number -= 4;
	}

	bitmap |= 0x01 << number;

	return bitmap;
}

static void set_leds_hidraw(int fd, uint8_t leds_bitmap)
{
	/*
	 * the total time the led is active (0xff means forever)
	 * |     duty_length: cycle time in deciseconds (0 - "blink very fast")
	 * |     |     ??? (Maybe a phase shift or duty_length multiplier?)
	 * |     |     |     % of duty_length led is off (0xff means 100%)
	 * |     |     |     |     % of duty_length led is on (0xff means 100%)
	 * |     |     |     |     |
	 * 0xff, 0x27, 0x10, 0x00, 0x32,
	 */
	uint8_t leds_report[] = {
		0x01,
		0x00, 0x00, 0x00, 0x00, 0x00, /* rumble values TBD */
		0x00, 0x00, 0x00, 0x00, 0x00, /* LED_1=0x02, LED_2=0x04 ... */
		0xff, 0x27, 0x10, 0x00, 0x32, /* LED_4 */
		0xff, 0x27, 0x10, 0x00, 0x32, /* LED_3 */
		0xff, 0x27, 0x10, 0x00, 0x32, /* LED_2 */
		0xff, 0x27, 0x10, 0x00, 0x32, /* LED_1 */
		0x00, 0x00, 0x00, 0x00, 0x00,
	};
	int ret;

	leds_report[10] = leds_bitmap;

	ret = write(fd, leds_report, sizeof(leds_report));
	if (ret == sizeof(leds_report))
		return;

	if (ret < 0)
		error("sixaxis: failed to set LEDS (%s)", strerror(errno));
	else
		error("sixaxis: failed to set LEDS (%d bytes written)", ret);
}

static bool set_leds_sysfs(struct leds_data *data)
{
	int i;

	if (!data->syspath_prefix)
		return false;

	/* start from 1, LED0 is never used */
	for (i = 1; i <= 4; i++) {
		char path[PATH_MAX] = { 0 };
		char buf[2] = { 0 };
		int fd;
		int ret;

		snprintf(path, PATH_MAX, "%s%d/brightness",
						data->syspath_prefix, i);

		fd = open(path, O_WRONLY);
		if (fd < 0) {
			error("sixaxis: cannot open %s (%s)", path,
							strerror(errno));
			return false;
		}

		buf[0] = '0' + !!(data->bitmap & (1 << i));
		ret = write(fd, buf, sizeof(buf));
		close(fd);
		if (ret != sizeof(buf))
			return false;
	}

	return true;
}

static gboolean setup_leds(GIOChannel *channel, GIOCondition cond,
							gpointer user_data)
{
	struct leds_data *data = user_data;

	if (!data)
		return FALSE;

	if (cond & (G_IO_HUP | G_IO_ERR | G_IO_NVAL))
		goto out;

	if(!set_leds_sysfs(data)) {
		int fd = g_io_channel_unix_get_fd(channel);
		set_leds_hidraw(fd, data->bitmap);
	}

out:
	leds_data_destroy(data);

	return FALSE;
}

static bool setup_device(int fd, int index, struct btd_adapter *adapter)
{
	char device_addr[18], master_addr[18], adapter_addr[18];
	bdaddr_t device_bdaddr, master_bdaddr;
	const bdaddr_t *adapter_bdaddr;
	struct btd_device *device;

	if (get_device_bdaddr(fd, &device_bdaddr) < 0)
		return false;

	if (get_master_bdaddr(fd, &master_bdaddr) < 0)
		return false;

	/* This can happen if controller was plugged while already connected
	 * eg. to charge up battery.
	 * Don't set LEDs in that case, hence return false */
	device = btd_adapter_find_device(adapter, &device_bdaddr,
							BDADDR_BREDR);
	if (device && btd_device_is_connected(device))
		return false;

	adapter_bdaddr = btd_adapter_get_address(adapter);

	if (bacmp(adapter_bdaddr, &master_bdaddr)) {
		if (set_master_bdaddr(fd, adapter_bdaddr) < 0)
			return false;
	}

	ba2str(&device_bdaddr, device_addr);
	ba2str(&master_bdaddr, master_addr);
	ba2str(adapter_bdaddr, adapter_addr);
	DBG("remote %s old_master %s new_master %s",
				device_addr, master_addr, adapter_addr);

	device = btd_adapter_get_device(adapter, &device_bdaddr, BDADDR_BREDR);

	if (g_slist_find_custom(btd_device_get_uuids(device), HID_UUID,
						(GCompareFunc)strcasecmp)) {
		DBG("device %s already known, skipping", device_addr);
		return true;
	}

	info("sixaxis: setting up new device");

	btd_device_device_set_name(device, devices[index].name);
	btd_device_set_pnpid(device, devices[index].source, devices[index].vid,
				devices[index].pid, devices[index].version);
	btd_device_set_temporary(device, FALSE);

	return true;
}

static int get_js_number(struct udev_device *udevice)
{
	struct udev_list_entry *devices, *dev_list_entry;
	struct udev_enumerate *enumerate;
	struct udev_device *hid_parent;
	const char *hidraw_node;
	const char *hid_id;
	int number = 0;

	hid_parent = udev_device_get_parent_with_subsystem_devtype(udevice,
								"hid", NULL);

	/*
	 * Look for HID_UNIQ first for the correct behavior via BT, if
	 * HID_UNIQ is not available it means the USB bus is being used and we
	 * can rely on HID_PHYS.
	 */
	hid_id = udev_device_get_property_value(hid_parent, "HID_UNIQ");
	if (!hid_id)
		hid_id = udev_device_get_property_value(hid_parent,
							"HID_PHYS");

	hidraw_node = udev_device_get_devnode(udevice);
	if (!hid_id || !hidraw_node)
		return 0;

	enumerate = udev_enumerate_new(udev_device_get_udev(udevice));
	udev_enumerate_add_match_sysname(enumerate, "js*");
	udev_enumerate_scan_devices(enumerate);
	devices = udev_enumerate_get_list_entry(enumerate);

	udev_list_entry_foreach(dev_list_entry, devices) {
		struct udev_device *input_parent;
		struct udev_device *js_dev;
		const char *input_id;
		const char *devname;

		devname = udev_list_entry_get_name(dev_list_entry);
		js_dev = udev_device_new_from_syspath(
						udev_device_get_udev(udevice),
						devname);

		input_parent = udev_device_get_parent_with_subsystem_devtype(
							js_dev, "input", NULL);
		if (!input_parent)
			goto next;

		/* check if this is the joystick relative to the hidraw device
		 * above */
		input_id = udev_device_get_sysattr_value(input_parent, "uniq");

		/*
		 * A strlen() check is needed because input device over USB
		 * have the UNIQ attribute defined but with an empty value.
		 */
		if (!input_id || strlen(input_id) == 0)
			input_id = udev_device_get_sysattr_value(input_parent,
								 "phys");

		if (!input_id)
			goto next;

		if (!strcmp(input_id, hid_id)) {
			number = atoi(udev_device_get_sysnum(js_dev));

			/* joystick numbers start from 0, leds from 1 */
			number++;

			udev_device_unref(js_dev);
			break;
		}
next:
		udev_device_unref(js_dev);
	}

	udev_enumerate_unref(enumerate);

	return number;
}

static char *get_leds_syspath_prefix(struct udev_device *udevice)
{
	struct udev_list_entry *dev_list_entry;
	struct udev_enumerate *enumerate;
	struct udev_device *hid_parent;
	const char *syspath;
	char *syspath_prefix;

	hid_parent = udev_device_get_parent_with_subsystem_devtype(udevice,
								"hid", NULL);

	enumerate = udev_enumerate_new(udev_device_get_udev(udevice));
	udev_enumerate_add_match_parent(enumerate, hid_parent);
	udev_enumerate_add_match_subsystem(enumerate, "leds");
	udev_enumerate_scan_devices(enumerate);

	dev_list_entry = udev_enumerate_get_list_entry(enumerate);
	if (!dev_list_entry) {
		syspath_prefix = NULL;
		goto out;
	}

	syspath = udev_list_entry_get_name(dev_list_entry);

	/*
	 * All the sysfs paths of the LEDs have the same structure, just the
	 * number changes, so strip it and store only the common prefix.
	 *
	 * Subtracting 1 here means assuming that the LED number is a single
	 * digit, this is safe as the kernel driver only exposes 4 LEDs.
	 */
	syspath_prefix = strndup(syspath, strlen(syspath) - 1);

out:
	udev_enumerate_unref(enumerate);

	return syspath_prefix;
}

static struct leds_data *get_leds_data(struct udev_device *udevice)
{
	struct leds_data *data;
	int number;

	number = get_js_number(udevice);
	DBG("number %d", number);

	data = malloc0(sizeof(*data));
	if (!data)
		return NULL;

	data->bitmap = calc_leds_bitmap(number);
	if (data->bitmap == 0) {
		leds_data_destroy(data);
		return NULL;
	}

	/*
	 * It's OK if this fails, set_leds_hidraw() will be used in
	 * case data->syspath_prefix is NULL.
	 */
	data->syspath_prefix = get_leds_syspath_prefix(udevice);

	return data;
}

static int get_supported_device(struct udev_device *udevice, uint16_t *bus)
{
	struct udev_device *hid_parent;
	uint16_t vid, pid;
	const char *hid_id;
	guint i;

	hid_parent = udev_device_get_parent_with_subsystem_devtype(udevice,
								"hid", NULL);
	if (!hid_parent)
		return -1;

	hid_id = udev_device_get_property_value(hid_parent, "HID_ID");

	if (sscanf(hid_id, "%hx:%hx:%hx", bus, &vid, &pid) != 3)
		return -1;

	for (i = 0; i < G_N_ELEMENTS(devices); i++) {
		if (devices[i].vid == vid && devices[i].pid == pid)
			return i;
	}

	return -1;
}

static void device_added(struct udev_device *udevice)
{
	struct btd_adapter *adapter;
	GIOChannel *io;
	uint16_t bus;
	int index;
	int fd;

	adapter = btd_adapter_get_default();
	if (!adapter)
		return;

	index = get_supported_device(udevice, &bus);
	if (index < 0)
		return;

	info("sixaxis: compatible device connected: %s (%04X:%04X)",
				devices[index].name, devices[index].vid,
				devices[index].pid);

	fd = open(udev_device_get_devnode(udevice), O_RDWR);
	if (fd < 0)
		return;

	io = g_io_channel_unix_new(fd);

	switch (bus) {
	case BUS_USB:
		if (!setup_device(fd, index, adapter))
			break;

		/* fall through */
	case BUS_BLUETOOTH:
		/* wait for events before setting leds */
		g_io_add_watch(io, G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL,
				setup_leds, get_leds_data(udevice));

		break;
	default:
		DBG("uknown bus type (%u)", bus);
		break;
	}

	g_io_channel_set_close_on_unref(io, TRUE);
	g_io_channel_unref(io);
}

static gboolean monitor_watch(GIOChannel *source, GIOCondition condition,
							gpointer data)
{
	struct udev_device *udevice;

	udevice = udev_monitor_receive_device(monitor);
	if (!udevice)
		return TRUE;

	if (!g_strcmp0(udev_device_get_action(udevice), "add"))
		device_added(udevice);

	udev_device_unref(udevice);

	return TRUE;
}

static int sixaxis_init(void)
{
	GIOChannel *channel;

	DBG("");

	ctx = udev_new();
	if (!ctx)
		return -EIO;

	monitor = udev_monitor_new_from_netlink(ctx, "udev");
	if (!monitor) {
		udev_unref(ctx);
		ctx = NULL;

		return -EIO;
	}

	/* Listen for newly connected hidraw interfaces */
	udev_monitor_filter_add_match_subsystem_devtype(monitor, "hidraw",
									NULL);
	udev_monitor_enable_receiving(monitor);

	channel = g_io_channel_unix_new(udev_monitor_get_fd(monitor));
	watch_id = g_io_add_watch(channel, G_IO_IN, monitor_watch, NULL);
	g_io_channel_unref(channel);

	return 0;
}

static void sixaxis_exit(void)
{
	DBG("");

	g_source_remove(watch_id);
	watch_id = 0;

	udev_monitor_unref(monitor);
	monitor = NULL;

	udev_unref(ctx);
	ctx = NULL;
}

BLUETOOTH_PLUGIN_DEFINE(sixaxis, VERSION, BLUETOOTH_PLUGIN_PRIORITY_LOW,
						sixaxis_init, sixaxis_exit)