#include <stdio.h>
#include <sys/types.h>

#include <libusb-1.0/libusb.h>
#include "scales.h"

#define DEBUG 1

static libusb_device* find_scale(libusb_device**);

int main(void)
{
	libusb_device **devs;
	int r;
	ssize_t cnt;
	libusb_device* dev;
	libusb_device_handle* handle;

	r = libusb_init(NULL);
	if (r < 0)
		return r;

	/*
	 * Get a list of USB devices
	 */
	cnt = libusb_get_device_list(NULL, &devs);
	if (cnt < 0)
		return (int) cnt;

	/*
	 * Look for a scale amongst the USB devices
	 */
	dev = find_scale(devs);
	
	/*
	 * Open a handle to this found scale
	 */
	libusb_open(dev, &handle);
#ifdef __linux__
	libusb_detach_kernel_driver(handle, 0);
#endif
	libusb_claim_interface(handle, 0);

	/*
	 * Try to transfer data about status
	 *
	 * http://www.beyondlogic.org/usbnutshell/usb6.shtml 
	 */
	unsigned char blah[8];
	libusb_control_transfer(
		handle,
		LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_CLASS |
		    LIBUSB_RECIPIENT_INTERFACE,
		//bmRequestType => direction: in, type: class,
		        //    recipient: interface
		0x01,   //bRequest => HID get report
		0x0300, //wValue => feature report
		0x00,   //windex => interface 0
		blah,
		8,    //wLength
		1000 //timeout => 1 sec
		);
	int i;
	for(i = 0; i < 8; i++) {
		printf("%x\n", blah[i]);
	}
	

	/*
	 * Free the device handle, device list and other cleanup
	 * tasks
	 */
#ifdef __linux__
	libusb_attach_kernel_driver(handle, 0);
#endif
	libusb_close(handle);
	libusb_free_device_list(devs, 1);
	libusb_exit(NULL);
	return 0;
}

static libusb_device* find_scale(libusb_device **devs)
{
	if(DEBUG)
		libusb_set_debug(NULL, 3);

	int i = 0;
	libusb_device* dev;

	/*
	 * Loop through each usb device, and for each device, loop through the
	 * scales list to see if it's one of our listed scales
	 */
	while ((dev = devs[i++]) != NULL) {
		struct libusb_device_descriptor desc;
		int r = libusb_get_device_descriptor(dev, &desc);
		if (r < 0) {
			fprintf(stderr, "failed to get device descriptor");
			return;
		}
        int i;
        for (i = 0; i < scalesc; i++) {
            if(desc.idVendor  == scales[i][0] && 
               desc.idProduct == scales[i][1]) {
				/*
				 * Debugging data about found scale
				 */
#ifdef DEBUG

				printf("Found scale %04x:%04x (bus %d, device %d)\n",
						desc.idVendor,
						desc.idProduct,
						libusb_get_bus_number(dev),
						libusb_get_device_address(dev));

					printf("It has descriptors:\n\tmanufc: %d\n\tprodct: %d\n\tserial: %d\n",
							desc.iManufacturer,
							desc.iProduct,
							desc.iSerialNumber);

					/*
					 * A char buffer to pull string descriptors in from the device
					 */
					unsigned char string[256];
					libusb_device_handle* hand;
					libusb_open(dev, &hand);

					r = libusb_get_string_descriptor_ascii(hand, desc.iManufacturer,
							string, 256);
					printf("Manufacturer: %s\n", string);
					libusb_close(hand);
#endif
					return dev;
					
                break;
            }
        }
	}
}