/*
 * razer-bw-te-ctl.c: Razer BlackWidow Tournament Edition control utility
 *
 * Everything has been reverse-engineered via Wireshark/usbmon and VirtualBox.
 *
 * Copyright (c) 2013, Přemysl Eric Janouch <p@janouch.name>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, 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.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <assert.h>

#include <getopt.h>
#include <strings.h>
#include <libusb.h>

#include "config.h"

// --- Utilities ---------------------------------------------------------------

/** Search for a device with given vendor and product ID. */
static libusb_device_handle *
find_device (int vendor, int product, int *error)
{
	libusb_device **list;
	libusb_device *found = NULL;
	libusb_device_handle *handle = NULL;
	int err = 0;

	ssize_t cnt = libusb_get_device_list (NULL, &list);
	if (cnt < 0)
		goto out;

	ssize_t i = 0;
	for (i = 0; i < cnt; i++)
	{
		libusb_device *device = list[i];

		struct libusb_device_descriptor desc;
		if (libusb_get_device_descriptor (device, &desc))
			continue;

		if (desc.idVendor == vendor && desc.idProduct == product)
		{
			found = device;
			break;
		}
	}

	if (found)
	{
		err = libusb_open (found, &handle);
		if (err)
			goto out_free;
	}

out_free:
	libusb_free_device_list(list, 1);
out:
	if (error != NULL && err != 0)
		*error = err;
	return handle;
}

// --- Device configuration ----------------------------------------------------

#define USB_VENDOR_RAZER  0x1532
#define USB_PRODUCT_RAZER_BW_TE  0x011c

#define USB_GET_REPORT  0x01
#define USB_SET_REPORT  0x09

#define BW_CTL_IFACE  0

/** Razer logo backlight mode. */
enum bw_led_mode
{
	LED_BRIGHTNESS = 0,
	LED_BLINK,
	LED_PULSATE
};

/** Overall device configuration. */
struct bw_config
{
	enum bw_led_mode led_mode;
	unsigned led_brightness;
	unsigned macro_led_on        : 1;
	unsigned macro_led_blinking  : 1;
	unsigned gaming_mode         : 1;
};

/** Send a command to the mouse via SET_REPORT. */
static int
bw_send_command (libusb_device_handle *device,
	unsigned char *data, uint16_t length)
{
	unsigned char packet[90] = { 0x00 };
	assert (length <= sizeof packet - 5);
	memcpy (packet + 5, data, length);

	unsigned char checksum = 0;
	while (length--)
		checksum ^= data[length];
	packet[sizeof packet - 2] = checksum;

	// XXX wIndex should actually be 0x0002 but that doesn't work
	int result = libusb_control_transfer (device, LIBUSB_ENDPOINT_OUT
		| LIBUSB_REQUEST_TYPE_CLASS | LIBUSB_RECIPIENT_INTERFACE,
		USB_SET_REPORT, 0x0300, 0x0000, packet, sizeof packet, 0);
	return result < 0 ? result : 0;
}

/** Set Razer logo backlight mode. */
static int
bw_set_led_mode (libusb_device_handle *device, enum bw_led_mode mode)
{
	unsigned char cmd[] = { 0x03, 0x03, 0x02, 0x01, 0x04, mode };
	return bw_send_command (device, cmd, sizeof cmd);
}

/** Set Razer logo backlight brightness. */
static int
bw_set_led_brightness (libusb_device_handle *device, unsigned char brightness)
{
	unsigned char cmd[] = { 0x03, 0x03, 0x03, 0x01, 0x04, brightness };
	return bw_send_command (device, cmd, sizeof cmd);
}

/** Set the on/off state of the macro LED. */
static int
bw_set_macro_led (libusb_device_handle *device, bool on)
{
	unsigned char cmd[] = { 0x03, 0x03, 0x00, 0x00, 0x07, on };
	return bw_send_command (device, cmd, sizeof cmd);
}

/** Set whether the macro LED should blink. */
static int
bw_set_macro_led_blinking (libusb_device_handle *device, bool blinking)
{
	unsigned char cmd[] = { 0x03, 0x03, 0x02, 0x00, 0x07, blinking };
	return bw_send_command (device, cmd, sizeof cmd);
}

/** Set the gaming mode (whether the Windows key should be ignored). */
static int
bw_set_gaming_mode (libusb_device_handle *device, bool on)
{
	unsigned char cmd[] = { 0x03, 0x03, 0x00, 0x01, 0x08, on };
	return bw_send_command (device, cmd, sizeof cmd);
}

// --- Control utility ---------------------------------------------------------

struct options
{
	unsigned set_led_mode            : 1;
	unsigned set_led_brightness      : 1;
	unsigned set_macro_led_on        : 1;
	unsigned set_macro_led_blinking  : 1;
	unsigned set_gaming_mode         : 1;
};

static void
show_usage (const char *program_name)
{
	printf ("Usage: %s [OPTION]...\n", program_name);
	printf ("Configure Razer BlackWidow Tournament Edition devices.\n\n");
	printf ("  -h, --help          Show this help\n");
	printf ("  --version           Show program version and exit\n");
	printf ("  --led-mode X        Set the mode of the Razer logo LED"
								 " (can be 'normal', 'blink' or 'pulsate')\n");
	printf ("  --led-brightness X  Set Razer logo LED brightness"
								 " (from 0 to 255)\n");
	printf ("  --macro-led X       Set the macro LED mode"
								 " ('off', 'on' or 'blink')\n");
	printf ("  --gaming-mode BOOL  Set whether the Windows key is ignored\n");
	printf ("\n");
}

static void
parse_options (int argc, char *argv[],
	struct options *options, struct bw_config *new_config)
{
	static struct option long_opts[] =
	{
		{ "help",           no_argument,       0, 'h' },
		{ "version",        no_argument,       0, 'V' },
		{ "led-mode",       required_argument, 0, 'l' },
		{ "led-brightness", required_argument, 0, 'L' },
		{ "macro-led",      required_argument, 0, 'm' },
		{ "gaming-mode",    required_argument, 0, 'g' },
		{ 0,                0,                 0,  0  }
	};

	if (argc == 1)
	{
		show_usage (argv[0]);
		exit (EXIT_FAILURE);
	}

	int c;
	while ((c = getopt_long (argc, argv, "h", long_opts, NULL)) != -1)
	{
	switch (c)
	{
	case 'h':
		show_usage (argv[0]);
		exit (EXIT_SUCCESS);
	case 'V':
		printf (PROJECT_NAME " " PROJECT_VERSION "\n");
		exit (EXIT_SUCCESS);
	case 'l':
		if (!strcasecmp (optarg, "normal"))
			new_config->led_mode = LED_BRIGHTNESS;
		else if (!strcasecmp (optarg, "blink"))
			new_config->led_mode = LED_BLINK;
		else if (!strcasecmp (optarg, "pulsate"))
			new_config->led_mode = LED_PULSATE;
		else
		{
			fprintf (stderr, "Error: invalid LED mode: %s\n", optarg);
			exit (EXIT_FAILURE);
		}
		options->set_led_mode = true;
		break;
	case 'L':
	{
		char *end;
		long bri = strtol (optarg, &end, 10);
		if (!*optarg || *end || bri < 0 || bri > 255)
		{
			fprintf (stderr, "Error: invalid LED brightness value\n");
			exit (EXIT_FAILURE);
		}
		options->set_led_brightness = true;
		break;
	}
	case 'm':
		if (!strcasecmp (optarg, "off"))
		{
			new_config->macro_led_on = false;
			new_config->macro_led_blinking = false;
		}
		else if (!strcasecmp (optarg, "blink"))
		{
			new_config->macro_led_on = true;
			new_config->macro_led_blinking = true;
		}
		else if (!strcasecmp (optarg, "on"))
		{
			new_config->macro_led_on = true;
			new_config->macro_led_blinking = false;
		}
		else
		{
			fprintf (stderr, "Error: invalid macro LED mode: %s\n", optarg);
			exit (EXIT_FAILURE);
		}
		options->set_macro_led_blinking = true;
		options->set_macro_led_on = true;
		break;
	case 'g':
		if (!strcasecmp (optarg, "true")
			|| !strcasecmp (optarg, "on")
			|| !strcasecmp (optarg, "yes"))
			new_config->gaming_mode = true;
		else if (!strcasecmp (optarg, "false")
			|| !strcasecmp (optarg, "off")
			|| !strcasecmp (optarg, "no"))
			new_config->gaming_mode = false;
		else
		{
			fprintf (stderr, "Error: invalid gaming mode"
				" setting: %s\n", optarg);
			exit (EXIT_FAILURE);
		}
		options->set_gaming_mode = true;
		break;
	case '?':
		exit (EXIT_FAILURE);
	}
	}

	if (optind < argc)
	{
		fprintf (stderr, "Error: extra parameters\n");
		exit (EXIT_FAILURE);
	}
}

static int
apply_options (libusb_device_handle *device,
	struct options *options, struct bw_config *new_config)
{
	int result;

	if (options->set_led_mode)
		if ((result = bw_set_led_mode
			(device, new_config->led_mode)))
			return result;
	if (options->set_led_brightness)
		if ((result = bw_set_led_brightness
			(device, new_config->led_brightness)))
			return result;

	if (options->set_macro_led_on)
		if ((result = bw_set_macro_led
			(device, new_config->macro_led_on)))
			return result;
	if (options->set_macro_led_blinking)
		if ((result = bw_set_macro_led_blinking
			(device, new_config->macro_led_blinking)))
			return result;

	if (options->set_gaming_mode)
		if ((result = bw_set_gaming_mode
			(device, new_config->gaming_mode)))
			return result;

	return 0;
}

#define ERROR(label, ...)                         \
	do {                                          \
		fprintf (stderr, "Error: " __VA_ARGS__);  \
		status = 1;                               \
		goto label;                               \
	} while (0)

int
main (int argc, char *argv[])
{
	struct options options = { 0 };
	struct bw_config new_config = { 0 };

	parse_options (argc, argv, &options, &new_config);

	int result, status = 0;

	result = libusb_init (NULL);
	if (result)
		ERROR (error_0, "libusb initialisation failed: %s\n",
			libusb_error_name (result));

	result = 0;
	libusb_device_handle *device = find_device
		(USB_VENDOR_RAZER, USB_PRODUCT_RAZER_BW_TE, &result);
	if (!device)
	{
		if (result)
			ERROR (error_1, "couldn't open device: %s\n",
				libusb_error_name (result));
		else
			ERROR (error_1, "no suitable device found\n");
	}

	bool reattach_driver = false;

	result = libusb_kernel_driver_active (device, BW_CTL_IFACE);
	switch (result)
	{
	case 0:
	case LIBUSB_ERROR_NOT_SUPPORTED:
		break;
	case 1:
		reattach_driver = true;
		result = libusb_detach_kernel_driver (device, BW_CTL_IFACE);
		if (result)
			ERROR (error_2, "couldn't detach kernel driver: %s\n",
				libusb_error_name (result));
		break;
	default:
		ERROR (error_2, "coudn't detect kernel driver presence: %s\n",
			libusb_error_name (result));
	}

	result = libusb_claim_interface (device, BW_CTL_IFACE);
	if (result)
		ERROR (error_3, "couldn't claim interface: %s\n",
			libusb_error_name (result));

	result = apply_options (device, &options, &new_config);
	if (result)
		ERROR (error_4, "operation failed: %s\n",
			libusb_error_name (result));

error_4:
	result = libusb_release_interface (device, BW_CTL_IFACE);
	if (result)
		ERROR (error_3, "couldn't release interface: %s\n",
			libusb_error_name (result));

error_3:
	if (reattach_driver)
	{
		result = libusb_attach_kernel_driver (device, BW_CTL_IFACE);
		if (result)
			ERROR (error_2, "couldn't reattach kernel driver: %s\n",
				libusb_error_name (result));
	}

error_2:
	libusb_close (device);
error_1:
	libusb_exit (NULL);
error_0:
	return status;
}