/*
 * Main API entry point
 *
 * Copyright (c) 2000-2003 Johannes Erdfelt <johannes@erdfelt.com>
 *
 * This library is covered by the LGPL, read LICENSE for details.
 */

#include <stdlib.h>	/* getenv */
#include <stdio.h>	/* stderr */
#include <string.h>	/* strcmp */
#include <errno.h>

#include "usbi.h"

int usb_debug = 0;
struct usb_bus *_usb_busses = NULL;

int usb_find_busses(void)
{
    struct usb_bus *busses, *bus;
    int ret, changes = 0;

    ret = usb_os_find_busses(&busses);
    if (ret < 0)
        return ret;

    /*
     * Now walk through all of the busses we know about and compare against
     * this new list. Any duplicates will be removed from the new list.
     * If we don't find it in the new list, the bus was removed. Any
     * busses still in the new list, are new to us.
     */
    bus = _usb_busses;
    while (bus)
    {
        int found = 0;
        struct usb_bus *nbus, *tbus = bus->next;

        nbus = busses;
        while (nbus)
        {
            struct usb_bus *tnbus = nbus->next;

            if (!strcmp(bus->dirname, nbus->dirname))
            {
                /* Remove it from the new busses list */
                LIST_DEL(busses, nbus);

                usb_free_bus(nbus);
                found = 1;
                break;
            }

            nbus = tnbus;
        }

        if (!found)
        {
            /* The bus was removed from the system */
            LIST_DEL(_usb_busses, bus);
            usb_free_bus(bus);
            changes++;
        }

        bus = tbus;
    }

    /*
     * Anything on the *busses list is new. So add them to usb_busses and
     * process them like the new bus it is.
     */
    bus = busses;
    while (bus)
    {
        struct usb_bus *tbus = bus->next;

        /*
         * Remove it from the temporary list first and add it to the real
         * usb_busses list.
         */
        LIST_DEL(busses, bus);

        LIST_ADD(_usb_busses, bus);

        changes++;

        bus = tbus;
    }

    return changes;
}

int usb_find_devices(void)
{
    struct usb_bus *bus;
    int ret, changes = 0;

    for (bus = usb_busses; bus; bus = bus->next)
    {
        struct usb_device *devices, *dev;

        /* Find all of the devices and put them into a temporary list */
        ret = usb_os_find_devices(bus, &devices);
        if (ret < 0)
            return ret;

        /*
         * Now walk through all of the devices we know about and compare
         * against this new list. Any duplicates will be removed from the new
         * list. If we don't find it in the new list, the device was removed.
         * Any devices still in the new list, are new to us.
         */
        dev = bus->devices;
        while (dev)
        {
            int found = 0;
            struct usb_device *ndev, *tdev = dev->next;

            ndev = devices;
            while (ndev)
            {
                struct usb_device *tndev = ndev->next;

                if (!strcmp(dev->filename, ndev->filename))
                {
                    /* Remove it from the new devices list */
                    LIST_DEL(devices, ndev);

                    usb_free_dev(ndev);
                    found = 1;
                    break;
                }

                ndev = tndev;
            }

            if (!found)
            {
                /* The device was removed from the system */
                LIST_DEL(bus->devices, dev);
                usb_free_dev(dev);
                changes++;
            }

            dev = tdev;
        }

        /*
         * Anything on the *devices list is new. So add them to bus->devices and
         * process them like the new device it is.
         */
        dev = devices;
        while (dev)
        {
            struct usb_device *tdev = dev->next;

            /*
             * Remove it from the temporary list first and add it to the real
             * bus->devices list.
             */
            LIST_DEL(devices, dev);

            /*
             * Some ports fetch the descriptors on scanning (like Linux) so we don't
             * need to fetch them again.
             */
            if (!dev->config)
            {
                usb_dev_handle *udev;

                udev = usb_open(dev);
                if (udev)
                {
                    usb_fetch_and_parse_descriptors(udev);

                    usb_close(udev);
                }
            }

			// [ID:2928293 Tim Green] 
			//
			if (dev->config) 
			{
				LIST_ADD(bus->devices, dev);
				changes++;
			}

            dev = tdev;
        }

        usb_os_determine_children(bus);
    }

    return changes;
}

void usb_init(void)
{
    if (getenv("USB_DEBUG"))
        usb_set_debug(atoi(getenv("USB_DEBUG")));

    usb_os_init();
}

usb_dev_handle *usb_open(struct usb_device *dev)
{
    usb_dev_handle *udev;

    udev = malloc(sizeof(*udev));
    if (!udev)
        return NULL;

    udev->fd = -1;
    udev->device = dev;
    udev->bus = dev->bus;
    udev->config = udev->interface = udev->altsetting = -1;

    if (usb_os_open(udev) < 0)
    {
        free(udev);
        return NULL;
    }

    return udev;
}

int usb_get_string(usb_dev_handle *dev, int index, int langid, char *buf,
                   size_t buflen)
{
    /*
     * We can't use usb_get_descriptor() because it's lacking the index
     * parameter. This will be fixed in libusb 1.0
     */
    return usb_control_msg(dev, USB_ENDPOINT_IN, USB_REQ_GET_DESCRIPTOR,
                           (USB_DT_STRING << 8) + index, langid, buf, (int)buflen, 1000);
}

int usb_get_string_simple(usb_dev_handle *dev, int index, char *buf, size_t buflen)
{
    char tbuf[255];	/* Some devices choke on size > 255 */
    int ret, langid, si, di;

    /*
     * Asking for the zero'th index is special - it returns a string
     * descriptor that contains all the language IDs supported by the
     * device. Typically there aren't many - often only one. The
     * language IDs are 16 bit numbers, and they start at the third byte
     * in the descriptor. See USB 2.0 specification, section 9.6.7, for
     * more information on this. */
    ret = usb_get_string(dev, 0, 0, tbuf, sizeof(tbuf));
    if (ret < 0)
        return ret;

    if (ret < 4)
        return -EIO;

    langid = tbuf[2] | (tbuf[3] << 8);

    ret = usb_get_string(dev, index, langid, tbuf, sizeof(tbuf));
    if (ret < 0)
        return ret;

    if (tbuf[1] != USB_DT_STRING)
        return -EIO;

    if (tbuf[0] > ret)
        return -EFBIG;

    for (di = 0, si = 2; si < tbuf[0]; si += 2)
    {
        if (di >= ((int)buflen - 1))
            break;

        if (tbuf[si + 1])	/* high byte */
            buf[di++] = '?';
        else
            buf[di++] = tbuf[si];
    }

    buf[di] = 0;

    return di;
}

int usb_close(usb_dev_handle *dev)
{
    int ret;

    ret = usb_os_close(dev);
    free(dev);

    return ret;
}

struct usb_device *usb_device(usb_dev_handle *dev)
{
    return dev->device;
}

void usb_free_dev(struct usb_device *dev)
{
    usb_destroy_configuration(dev);
    free(dev->children);
    free(dev);
}

struct usb_bus *usb_get_busses(void)
{
    return _usb_busses;
}

void usb_free_bus(struct usb_bus *bus)
{
    free(bus);
}