/* -*- Mode: C; indent-tabs-mode:t ; c-basic-offset:8 -*- */

/*

 * libusb example program for hotplug API

 * Copyright © 2012-2013 Nathan Hjelm <hjelmn@mac.com>

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include <stdlib.h>

#include <stdio.h>

#include "libusb.h"

int done = 0;

libusb_device_handle *handle = NULL;

static int LIBUSB_CALL hotplug_callback(libusb_context *ctx, libusb_device *dev, libusb_hotplug_event event, void *user_data)

{

	struct libusb_device_descriptor desc;

	int rc;

	(void)ctx;

	(void)dev;

	(void)event;

	(void)user_data;

	rc = libusb_get_device_descriptor(dev, &desc);

	if (LIBUSB_SUCCESS != rc) {

		fprintf (stderr, "Error getting device descriptor\n");

	}

	printf ("Device attached: %04x:%04x\n", desc.idVendor, desc.idProduct);

	if (handle) {

		libusb_close (handle);

		handle = NULL;

	}

	rc = libusb_open (dev, &handle);

	if (LIBUSB_SUCCESS != rc) {

		fprintf (stderr, "Error opening device\n");

	}

	done++;

	return 0;

}

static int LIBUSB_CALL hotplug_callback_detach(libusb_context *ctx, libusb_device *dev, libusb_hotplug_event event, void *user_data)

{

	(void)ctx;

	(void)dev;

	(void)event;

	(void)user_data;

	printf ("Device detached\n");

	if (handle) {

		libusb_close (handle);

		handle = NULL;

	}

	done++;

	return 0;

}

int main(int argc, char *argv[])

{

	libusb_hotplug_callback_handle hp[2];

	int product_id, vendor_id, class_id;

	int rc;

	vendor_id  = (argc > 1) ? (int)strtol (argv[1], NULL, 0) : 0x045a;

	product_id = (argc > 2) ? (int)strtol (argv[2], NULL, 0) : 0x5005;

	class_id   = (argc > 3) ? (int)strtol (argv[3], NULL, 0) : LIBUSB_HOTPLUG_MATCH_ANY;

	rc = libusb_init (NULL);

	if (rc < 0)

	{

		printf("failed to initialise libusb: %s\n", libusb_error_name(rc));

		return EXIT_FAILURE;

	}

	if (!libusb_has_capability (LIBUSB_CAP_HAS_HOTPLUG)) {

		printf ("Hotplug capabilites are not supported on this platform\n");

		libusb_exit (NULL);

		return EXIT_FAILURE;

	}

	rc = libusb_hotplug_register_callback (NULL, LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED, 0, vendor_id,

		product_id, class_id, hotplug_callback, NULL, &hp[0]);

	if (LIBUSB_SUCCESS != rc) {

		fprintf (stderr, "Error registering callback 0\n");

		libusb_exit (NULL);

		return EXIT_FAILURE;

	}

	rc = libusb_hotplug_register_callback (NULL, LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT, 0, vendor_id,

		product_id,class_id, hotplug_callback_detach, NULL, &hp[1]);

	if (LIBUSB_SUCCESS != rc) {

		fprintf (stderr, "Error registering callback 1\n");

		libusb_exit (NULL);

		return EXIT_FAILURE;

	}

	while (done < 2) {

		rc = libusb_handle_events (NULL);

		if (rc < 0)

			printf("libusb_handle_events() failed: %s\n", libusb_error_name(rc));

	}

	if (handle) {

		libusb_close (handle);

	}

	libusb_exit (NULL);

	return EXIT_SUCCESS;

}