/*
 * Copyright (C) 2016 Paul Kocialkowski <contact@paulk.fr>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <unistd.h>
#include <sys/types.h>
#include <libusb.h>

#include "lg-downloader.h"
#include "usb.h"

int usb_open(struct context *context)
{
	struct libusb_device_handle *handle;
	int configuration;
	int rc;

	if (context == NULL)
		return -1;

	rc = libusb_init(NULL);
	if (rc < 0) {
		fprintf(stderr, "Initializing USB failed\n");
		return -1;
	}

	do {
		handle = libusb_open_device_with_vid_pid(NULL, USB_VENDOR_LG, USB_DEVICE_DOWNLOAD);
		if (handle != NULL)
			break;

		usleep(300000);
	} while (context->wait);

	if (handle == NULL) {
		fprintf(stderr, "Finding and opening USB device failed\n");
		fprintf(stderr, "\nDevice might be missing or you may not have the rights to do this\n");
		goto error;
	}

	libusb_detach_kernel_driver(handle, USB_INTERFACE);

	rc = libusb_get_configuration(handle, &configuration);
	if (rc < 0) {
		fprintf(stderr, "Getting USB configuration failed\n");
		goto error;
	}

	if (configuration != USB_CONFIGURATION) {
		rc = libusb_set_configuration(handle, USB_CONFIGURATION);
		if (rc < 0) {
			fprintf(stderr, "Setting USB configuration failed\n");
			goto error;
		}
	}

	rc = libusb_claim_interface(handle, USB_INTERFACE);
	if (rc < 0) {
		fprintf(stderr, "Claiming USB interface failed\n");
		goto error;
	}

	context->usb_handle = handle;

	rc = 0;
	goto complete;

error:
	rc = -1;

	if (handle != NULL)
		libusb_close(handle);

	libusb_exit(NULL);

complete:
	return rc;
}

void usb_close(struct context *context)
{
	if (context == NULL)
		return;

	if (context->usb_handle != NULL) {
		libusb_release_interface(context->usb_handle, USB_INTERFACE);
		libusb_close(context->usb_handle);

		context->usb_handle = NULL;

		libusb_exit(NULL);
	}
}

int usb_send(struct context *context, const void *data, size_t size)
{
	size_t count;
	size_t chunk;
	uint8_t *p;
	int transferred;
	int rc;

	if (context == NULL)
		return -1;

	count = 0;
	p = (uint8_t *) data;

	while (count < size) {
		chunk = (size - count) < USB_SEND_CHUNK ? (size - count) : USB_SEND_CHUNK;

		rc = libusb_bulk_transfer(context->usb_handle, USB_ENDPOINT_OUT, p, chunk, &transferred, USB_TIMEOUT);
		if (rc < 0 || transferred <= 0) {
			fprintf(stderr, "Bulk USB transfer failed\n");
			return -1;
		}

		count += transferred;
		p += transferred;
	}

	return 0;
}

int usb_recv(struct context *context, void *data, size_t size)
{
	size_t count;
	size_t chunk;
	uint8_t *p;
	int transferred;
	int rc;

	if (context == NULL)
		return -1;

	count = 0;
	p = (uint8_t *) data;

	while (count < size) {
		chunk = (size - count) < USB_RECV_CHUNK ? (size - count) : USB_RECV_CHUNK;

		rc = libusb_bulk_transfer(context->usb_handle, USB_ENDPOINT_IN, p, chunk, &transferred, USB_TIMEOUT);
		if (rc < 0 || transferred <= 0) {
			fprintf(stderr, "Bulk USB transfer failed\n");
			return -1;
		}

		count += transferred;
		p += transferred;
	}

	return 0;
}

int usb_recv_available(struct context *context, void *data, size_t size)
{
	size_t chunk;
	int transferred;
	int rc;

	if (context == NULL)
		return -1;

	chunk = size < USB_RECV_CHUNK ? size : USB_RECV_CHUNK;

	rc = libusb_bulk_transfer(context->usb_handle, USB_ENDPOINT_IN, data, chunk, &transferred, USB_TIMEOUT);
	if (rc < 0 || transferred <= 0) {
		fprintf(stderr, "Bulk USB transfer failed\n");
		return -1;
	}

	return transferred;
}