/*-*- linux-c -*-*/

/*
 * Copyright (C) 2009 Lennart Poettering <lennart@poettering.net>
 *
 * 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:
 */

#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <inttypes.h>
#include <ctype.h>
#include <stdlib.h>

#include <libudev.h>

static int get_vid_pid(
	struct udev_device *usb,
	uint16_t *vid,
	uint16_t *pid) {

	const char *t;

	if ((t = udev_device_get_sysattr_value(usb, "idVendor"))) {
		unsigned u;

		if (sscanf(t, "%04x", &u) != 1 || u <= 0 || u > 0xFFFFU) {
			fprintf(stderr, "Failed to parse idVendor on %s.\n", udev_device_get_syspath(usb));
			return -1;
		}

		*vid = (uint16_t) u;
	}

	if ((t = udev_device_get_sysattr_value(usb, "idProduct"))) {
		unsigned u;

		if (sscanf(t, "%04x", &u) != 1 || u > 0xFFFFU) {
			fprintf(stderr, "Failed to parse idProduct on %s.\n", udev_device_get_syspath(usb));
			return -1;
		}

		*pid = (uint16_t) u;
	}

	return 0;
}

static void rstrip(char *n) {
	size_t i;

	for (i = strlen(n); i > 0 && isspace(n[i-1]); i--)
		n[i-1] = 0;
}

#define HEXCHARS "0123456789abcdefABCDEF"
#define WHITESPACE " \t\n\r"

static int lookup_vid_pid(
	uint16_t vid,
	uint16_t pid,
	char **vendor,
	char **product) {

	FILE *f;
	int ret = -1;
	int found_vendor = 0;
	char *line = NULL;

	*vendor = *product = NULL;

	if (!(f = fopen(USB_DATABASE, "r"))) {
		fprintf(stderr, "Failed to open database file "USB_DATABASE": %s", strerror(errno));
		return -1;
	}

	for (;;) {
		size_t n;

		if (line) {
			free(line);
			line = NULL;
		}

		if (getline(&line, &n, f) < 0)
			break;

		rstrip(line);

		if (line[0] == '#' || line[0] == 0)
			continue;

		if (strspn(line, HEXCHARS) == 4) {
			unsigned u;

			if (found_vendor)
				break;

			if (sscanf(line, "%04x", &u) == 1 && u == vid) {
				char *t;

				t = line+4;
				t += strspn(t, WHITESPACE);

				if (!(*vendor = strdup(t))) {
					fprintf(stderr, "Out of memory.\n");
					goto finish;
				}

				found_vendor = 1;
			}

			continue;
		}

		if (found_vendor && line[0] == '\t' && strspn(line+1, HEXCHARS) == 4) {
			unsigned u;

			if (sscanf(line+1, "%04x", &u) == 1 && u == pid) {
				char *t;

				t = line+5;
				t += strspn(t, WHITESPACE);

				if (!(*product = strdup(t))) {
					fprintf(stderr, "Out of memory.\n");
					goto finish;
				}

				break;
			}
		}
	}

	ret = 0;

finish:
	free(line);

	fclose(f);

	if (ret < 0) {
		free(*product);
		free(*vendor);

		*product = *vendor = NULL;
	}

	return ret;
}

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

	struct udev *udev = NULL;
	int ret = 1;
	char *sp;
	struct udev_device *dev = NULL, *usb = NULL;
	uint16_t vid = 0, pid = 0;
	char *vendor = NULL, *product = NULL;

	if (argc < 2) {
		fprintf(stderr, "Need to pass sysfs path.\n");
		goto finish;
	}

	if (!(udev = udev_new()))
		goto finish;

	if (asprintf(&sp, "%s/%s", udev_get_sys_path(udev), argv[1]) < 0) {
		fprintf(stderr, "Failed to allocate sysfs path.\n");
		goto finish;
	}

	dev = udev_device_new_from_syspath(udev, sp);
	free(sp);

	if (!dev) {
		fprintf(stderr, "Failed to access %s.\n", argv[1]);
		goto finish;
	}

	if (!(usb = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_device"))) {
		fprintf(stderr, "Failed to find usb_device.\n");
		goto finish;
	}

	if (get_vid_pid(usb, &vid, &pid) < 0)
		goto finish;

	if (lookup_vid_pid(vid, pid, &vendor, &product) < 0)
		goto finish;

	if (vendor)
		printf("ID_VENDOR_FROM_DATABASE=%s\n", vendor);

	if (product)
		printf("ID_MODEL_FROM_DATABASE=%s\n", product);

	ret = 0;

finish:
	if (dev)
		udev_device_unref(dev);

	if (udev)
		udev_unref(udev);

	free(vendor);
	free(product);

	return ret;

}