/*
 * Copyright © 2009 Keith Packard <keithp@keithp.com>
 *
 * 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; version 2 of the License.
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 */

#include "aoview.h"
#include <ctype.h>
#include <dirent.h>

static char *
load_string(char *dir, char *file)
{
	char	*full = aoview_fullname(dir, file);
	char	line[4096];
	char	*r;
	FILE	*f;
	int	rlen;

	f = fopen(full, "r");
	free(full);
	if (!f)
		return NULL;
	r = fgets(line, sizeof (line), f);
	fclose(f);
	if (!r)
		return NULL;
	rlen = strlen(r);
	if (r[rlen-1] == '\n')
		r[rlen-1] = '\0';
	return strdup(r);
}

static int
load_hex(char *dir, char *file)
{
	char	*line;
	char	*end;
	long	i;

	line = load_string(dir, file);
	if (!line)
		return -1;
	i = strtol(line, &end, 16);
	free(line);
	if (end == line)
		return -1;
	return i;
}

static int
dir_filter_tty_colon(const struct dirent *d)
{
	return strncmp(d->d_name, "tty:", 4) == 0;
}

static int
dir_filter_tty(const struct dirent *d)
{
	return strncmp(d->d_name, "tty", 3) == 0;
}

static char *
usb_tty(char *sys)
{
	char *base;
	int num_configs;
	int config;
	struct dirent **namelist;
	int interface;
	int num_interfaces;
	char endpoint_base[20];
	char *endpoint_full;
	char *tty_dir;
	int ntty;
	char *tty;

	base = aoview_basename(sys);
	num_configs = load_hex(sys, "bNumConfigurations");
	num_interfaces = load_hex(sys, "bNumInterfaces");
	for (config = 1; config <= num_configs; config++) {
		for (interface = 0; interface < num_interfaces; interface++) {
			sprintf(endpoint_base, "%s:%d.%d",
				base, config, interface);
			endpoint_full = aoview_fullname(sys, endpoint_base);

			/* Check for tty:ttyACMx style names
			 */
			ntty = scandir(endpoint_full, &namelist,
				       dir_filter_tty_colon,
				       alphasort);
			if (ntty > 0) {
				free(endpoint_full);
				tty = aoview_fullname("/dev", namelist[0]->d_name + 4);
				free(namelist);
				return tty;
			}

			/* Check for tty/ttyACMx style names
			 */
			tty_dir = aoview_fullname(endpoint_full, "tty");
			free(endpoint_full);
			ntty = scandir(tty_dir, &namelist,
				       dir_filter_tty,
				       alphasort);
			free (tty_dir);
			if (ntty > 0) {
				tty = aoview_fullname("/dev", namelist[0]->d_name);
				free(namelist);
				return tty;
			}
		}
	}
	return NULL;
}

static struct usbdev *
usb_scan_device(char *sys)
{
	struct usbdev *usbdev;

	usbdev = calloc(1, sizeof (struct usbdev));
	if (!usbdev)
		return NULL;
	usbdev->sys = strdup(sys);
	usbdev->manufacturer = load_string(sys, "manufacturer");
	usbdev->product = load_string(sys, "product");
	usbdev->serial = load_string(sys, "serial");
	usbdev->idProduct = load_hex(sys, "idProduct");
	usbdev->idVendor = load_hex(sys, "idVendor");
	usbdev->tty = usb_tty(sys);
	return usbdev;
}

void
aoview_usbdev_free(struct usbdev *usbdev)
{
	free(usbdev->sys);
	free(usbdev->manufacturer);
	free(usbdev->product);
	free(usbdev->serial);
	free(usbdev->tty);
	free(usbdev);
}

#define USB_DEVICES	"/sys/bus/usb/devices"

static int
dir_filter_dev(const struct dirent *d)
{
	const char	*n = d->d_name;
	char	c;

	while ((c = *n++)) {
		if (isdigit(c))
			continue;
		if (c == '-')
			continue;
		if (c == '.' && n != d->d_name + 1)
			continue;
		return 0;
	}
	return 1;
}

int
aoview_usb_scan(struct usbdev ***devs_ret)
{
	int		n;
	int		ndev = 0;
	int		e;
	struct dirent	**ents;
	char		*dir;
	struct usbdev	**devs = NULL;
	struct usbdev	*dev;

	n = scandir (USB_DEVICES, &ents,
		     dir_filter_dev,
		     alphasort);
	if (!n)
		return 0;
	for (e = 0; e < n; e++) {
		dir = aoview_fullname(USB_DEVICES, ents[e]->d_name);
		dev = usb_scan_device(dir);
		free(dir);
		if (dev->idVendor == 0xfffe && dev->tty) {
			if (devs)
				devs = realloc(devs, ndev + 1 * sizeof (struct usbdev *));
			else
				devs = malloc (sizeof (struct usbdev *));
			devs[ndev++] = dev;
		}
	}
	free(ents);
	*devs_ret = devs;
	return ndev;
}