#include <stdio.h>
#include <string.h>
#include <usb.h>
#include <errno.h>
#include <unistd.h>

#define VENDOR_ID 0x1130
#define PRODUCT_ID 0x660c

/* commands */
#define TEMPER_CMD_TYPE 0x21
#define TEMPER_CMD_REQUEST 9
#define TEMPER_CMD 0x200

#define CMDLEN 32
char temper_init[CMDLEN]     = "\x0a\x0b\x0c\x0d\x00\x00\x02\x00";
char temper_end[CMDLEN]      = "\x0a\x0b\x0c\x0d\x00\x00\x01\x00";
char temper_measure[CMDLEN]  = "\x54\x00\x00\x00\x00\x00\x00\x00";
char temper_nvram[CMDLEN]    = "\x52\x00\x00\x00\x00\x00\x00\x00";
char temper_highprec[CMDLEN] = "\x43\x00\x00\x00\x00\x00\x00\x00";
char temper_null[CMDLEN]     = { 0 };

/* read */
#define TEMPER_READ_TYPE 0xa1
#define TEMPER_READ_REQUEST 1
#define TEMPER_READ 0x300
#define DATALEN 256

struct usb_device *
find_usb_device_by_id(struct usb_bus *busses,
		      int vendor, int product)
{
  struct usb_bus *bus;
  struct usb_device *dev;  

  for (bus = busses; bus; bus = bus -> next) {
    for (dev = bus -> devices; dev; dev = dev -> next) {
      if (dev->descriptor.idVendor == vendor &&
	  dev->descriptor.idProduct == product)
	return dev;
    }
  }
  return NULL;
}

int main(int argc, char **argv)
{
  struct usb_bus *busses;
  struct usb_device *dev;  
  usb_dev_handle *handle;
  int interface;
  int timeout = 1000;
  int i, ret;
  char data[DATALEN];
  double temperature;
  int testcmd = 0;

  if (argc>1)
    testcmd = atoi(argv[1]);

  usb_set_debug(0);
  usb_init();
  usb_find_busses();
  usb_find_devices();
  busses = usb_get_busses();

  if (!(dev = find_usb_device_by_id(busses, VENDOR_ID, PRODUCT_ID))) {
    fprintf(stderr, "TEMPer device not found\n");
    exit(EXIT_FAILURE);
  }

  //  printf("TEMPer found, device %d\n", dev->devnum);

  if (!(handle = usb_open(dev))) {
    perror("usb_open");
    exit(EXIT_FAILURE);
  }


  for (interface=0; interface<=1; interface++)
    if (usb_detach_kernel_driver_np(handle, interface) < 0) {
      if (errno==ENODATA) {
	//	fprintf(stderr, "interface %d already detached\n", interface);
      } else {
	perror("usb_detach_kernel_driver_np");
	fprintf(stderr, "detach %d failed, continuing anyway\n", interface);
      }
    }

  interface = dev->config->interface->altsetting->bInterfaceNumber;
  //  fprintf(stderr, "interface %d\n", interface);

  if (usb_claim_interface(handle,interface) < 0) {
    usb_close(handle);
    fprintf(stderr, "Failed to claim interface\n");
    exit(EXIT_FAILURE);
  }

  if ((usb_control_msg(handle, TEMPER_CMD_TYPE, TEMPER_CMD_REQUEST,
			TEMPER_CMD, 1, temper_init, CMDLEN, timeout)) != CMDLEN) {
	perror("usb_control_msg(init)");
	exit(EXIT_FAILURE);
  }

#ifdef HIGHPREC
  if ((usb_control_msg(handle, TEMPER_CMD_TYPE, TEMPER_CMD_REQUEST,
			TEMPER_CMD, 1, temper_highprec, CMDLEN, timeout)) != CMDLEN) {
	perror("usb_control_msg(init)");
	exit(EXIT_FAILURE);
  }
#endif
  if ((usb_control_msg(handle, TEMPER_CMD_TYPE, TEMPER_CMD_REQUEST,
			TEMPER_CMD, 1, temper_measure, CMDLEN, timeout)) != CMDLEN) {
	perror("usb_control_msg(measure)");
	exit(EXIT_FAILURE);
  }
  for (i=7; i--;)
    if ((usb_control_msg(handle, TEMPER_CMD_TYPE, TEMPER_CMD_REQUEST,
			  TEMPER_CMD, 1, temper_null, CMDLEN, timeout)) != CMDLEN) {
	perror("usb_control_msg(null)");
	exit(EXIT_FAILURE);
  }
  if ((usb_control_msg(handle, TEMPER_CMD_TYPE, TEMPER_CMD_REQUEST,
			TEMPER_CMD, 1, temper_end, CMDLEN, timeout)) != CMDLEN) {
	perror("usb_control_msg(end)");
	exit(EXIT_FAILURE);
  }

  usleep(500000);

  if ((ret=usb_control_msg(handle, TEMPER_READ_TYPE, TEMPER_READ_REQUEST,
			TEMPER_READ, 1, data, DATALEN, timeout)) < 2) {
	perror("usb_control_msg(read)");
	exit(EXIT_FAILURE);
  }

  printf("Raw data: 0x%02x:%02x = %d %d\n", data[0], (unsigned char)data[1], 
	 (unsigned char)data[0], (unsigned char)data[1]);

  temperature = data[0] + ((unsigned char)data[1])/256.0;
  printf("%.2f degrees Celcius\n", temperature);

  usb_release_interface(handle,interface);
  usb_close(handle);

  exit(EXIT_SUCCESS);
}