/*
 * Copyright (c) 2012
 * 	Lars-Dominik Braun <lars@6xq.net>
 * 
 * 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 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 <string.h>
#include <assert.h>
#include <stdio.h>

#include "usb.h"

/* our software identifier */
#define HIDPP_SOFTWARE_ID 0xB
#define HIDPP_USB_INTERFACE 2

/*	send packet to device, blocking
 */
int hidppUsbSend (libusb_device_handle * const dev,
		const hidppPacket_t * const p) {
	assert (dev != NULL);
	assert (p != NULL);
	//assert (p->devId >= 0x1);
	assert (p->devId <= HIDPP_DEVID_ROOT);

	const unsigned int timeout = 500;
	unsigned char packet[7] = {p->id, p->devId, p->featureIdx,
			(p->function<<4) | p->softwareId};
	int ret;
	memcpy (&packet[4], p->args, 3);

	/* FIXME: magic numbers */
	ret = libusb_control_transfer (dev, LIBUSB_REQUEST_TYPE_CLASS |
			LIBUSB_RECIPIENT_INTERFACE, LIBUSB_REQUEST_SET_CONFIGURATION,
			0x0210, 0x0002, packet, sizeof (packet)/sizeof (*packet), timeout);
	if (ret < 0) {
		printf ("<< failed! %s", libusb_error_name (ret));
		return HIDPP_RET_USB_ERROR;
	}
	dumphex ("<< ", packet, sizeof (packet));

	return HIDPP_RET_OK;
}

/*	receive single packet from device, blocking
 */
hidppReturn_t hidppUsbReceive (libusb_device_handle * const dev,
		hidppPacket_t * const p) {
	int len, ret;
	unsigned char packet[HIDPP_MAX_PACKETLEN];
	const unsigned int timeout = 500;

	assert (dev != NULL);
	assert (p != NULL);

	ret = libusb_bulk_transfer (dev, 0x83, packet, sizeof (packet), &len,
			timeout);
	if (ret != LIBUSB_SUCCESS) {
		printf (">> failed! %s\n", libusb_error_name (ret));
		return HIDPP_RET_USB_ERROR;
	}
	dumphex (">> ", packet, len);

	memset (p, 0, sizeof (*p));
	p->id = packet[0];
	p->devId = packet[1];
	if (packet[2] == 0x8F || packet[2] == 0xFF) {
		/* error */
		assert (len > 6);
		p->featureIdx = packet[3];
		p->function = (packet[4] >> 4) & 0xf;
		p->softwareId = packet[4] & 0xf;
		p->error = packet[6];
	} else {
		assert (len > 3);
		p->featureIdx = packet[2];
		p->function = (packet[3] >> 4) & 0xf;
		p->softwareId = packet[3] & 0xf;
		if (len > 4) {
			memcpy (p->args, &packet[4], len-4);
		}
	}

	return HIDPP_RET_OK;
}

/*	initialize packet
 */
void hidppUsbPacketInit (hidppPacket_t * const p, const hidppDeviceId_t devId,
		const uint8_t featureIdx, const uint8_t function,
		const uint8_t softwareId, const uint8_t * const args,
		const size_t argsSize) {
	assert (p != NULL);
	assert (argsSize < 16);

	memset (p, 0, sizeof (*p));

	if (argsSize < 4) {
		p->id = 0x10;
	} else if (argsSize < 16) {
		p->id = 0x11;
	}
	p->devId = devId;
	p->featureIdx = featureIdx;
	/* function is just four bits */
	assert (function < (1<<4));
	p->function = function & 0xf;
	/* software id is just four bits */
	assert (softwareId < (1<<4));
	p->softwareId = softwareId & 0xf;
	if (args != NULL) {
		assert (argsSize > 0);
		assert (argsSize < sizeof (p->args)/sizeof (*p->args));
		memcpy (p->args, args, argsSize);
	}
}

/*	high-level request wrapper, drops events/notifications from device
 */
hidppReturn_t hidppUsbRequest (hidppDevice_t * const d,
		const hidppFeatureId_t feature, const uint8_t function,
		const uint8_t * const args, const size_t argsCount,
		hidppPacket_t * const rp) {
	hidppReturn_t ret;
	hidppPacket_t sp;
	uint8_t featureIdx;

	if (!hidppFeatureIdToIdx (d, feature, &featureIdx)) {
		assert (0);
		return HIDPP_RET_ERROR;
	}
	hidppUsbPacketInit (&sp, d->id, featureIdx, function, HIDPP_SOFTWARE_ID,
			args, argsCount);
	ret = hidppUsbSend (d->usbDev, &sp);

	while (ret == HIDPP_RET_OK) {
		if ((ret = hidppUsbReceive (d->usbDev, rp)) == HIDPP_RET_OK) {
			if ((rp->id != 0x10 && rp->id != 0x11) ||
					rp->featureIdx != sp.featureIdx ||
					rp->function != sp.function ||
					rp->softwareId != sp.softwareId) {
				/* ignore non-hid++ packets, events and packets not meant for us */
				continue;
			} else {
				return HIDPP_RET_OK;
			}
		}
	}

	return ret;
}

void hidppUsbDeviceOpen (libusb_device * const dev, libusb_device_handle **handle) {
	int ret;

	ret = libusb_open (dev, handle);
	assert (ret == LIBUSB_SUCCESS);

	if (libusb_kernel_driver_active (*handle, HIDPP_USB_INTERFACE) == 1) {
		ret = libusb_detach_kernel_driver (*handle, HIDPP_USB_INTERFACE);
		assert (ret == LIBUSB_SUCCESS);
	}
	ret = libusb_claim_interface (*handle, HIDPP_USB_INTERFACE);
	assert (ret == LIBUSB_SUCCESS);
}

void hidppUsbDeviceClose (libusb_device_handle *handle) {
	int ret;

	ret = libusb_release_interface (handle, HIDPP_USB_INTERFACE);
	assert (ret == LIBUSB_SUCCESS);
	ret = libusb_attach_kernel_driver (handle, HIDPP_USB_INTERFACE);
	assert (ret == LIBUSB_SUCCESS);

	libusb_close (handle);
}