#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>

#include "usb.h"

static libusb_context *ctx;
libusb_device *dev;
libusb_device_handle *hdev;

void find_device(char *name,
                 unsigned int vendor,
                 unsigned int device)
{
    struct libusb_device_descriptor ddesc;
    libusb_device **devs = NULL;
    int rc, i, n;

    if (!ctx) {
        rc = libusb_init(&ctx);
        if (rc != 0) {
            fprintf(stderr, "libusb_init failed (%d)\n", rc);
            exit(1);
        }
        libusb_set_debug(ctx, LIBUSB_LOG_LEVEL_INFO);
    }

    n = libusb_get_device_list(ctx, &devs);
    for (i = 0; i < n; i++) {
        rc = libusb_get_device_descriptor(devs[i], &ddesc);
        if (rc != 0) {
            fprintf(stderr, "libusb_get_device_descriptor failed (%d)\n", rc);
            exit(1);
        }
        if (vendor != ddesc.idVendor)
            continue;
        if (device != ddesc.idProduct)
            continue;
        dev = devs[i];
        fprintf(stderr, "%s found at %d:%d\n", name,
                libusb_get_bus_number(dev),
                libusb_get_device_address(dev));
        libusb_free_device_list(devs, 1);

        rc = libusb_open(dev, &hdev);
        if (rc != 0) {
            fprintf(stderr, "libusb_open failed (%d)\n", rc);
            exit(1);
        }
        libusb_set_auto_detach_kernel_driver(hdev, 1);
        rc = libusb_claim_interface(hdev, 0);
        if (rc != 0) {
            fprintf(stderr, "libusb_claim_interface failed (%d)\n", rc);
            exit(1);
        }
        return;
    }
    fprintf(stderr, "%s not found\n", name);
    exit(1);
}