/*
 * This is placed into the Public Domain by Jochen Kunz.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <sys/types.h>
#include <limits.h>

#include "hidapi.h"

#define	WSTRLEN		256
#define	BUFLEN		16
#define	VENDOR_ID	0x046d
#define	PRODUCT_ID	0xc626


int
print_dev_info( hid_device* dev) {
	wchar_t wstr[ WSTRLEN];
	if (hid_get_manufacturer_string( dev, wstr, WSTRLEN) < 0) {
		printf( "hid_get_manufacturer_string() failed!\n");
	} else {
		printf( "hid_get_manufacturer_string()=%ls\n", wstr);
	}

	if (hid_get_product_string( dev, wstr, WSTRLEN) < 0) {
		printf( "hid_get_product_string() failed!\n");
	} else {
		printf( "hid_get_product_string()=%ls\n", wstr);
	}

	if (hid_get_serial_number_string( dev, wstr, WSTRLEN) < 0) {
		printf( "hid_get_serial_number_string() failed!\n");
	} else {
		printf( "hid_get_serial_number_string()=%ls\n", wstr);
	}
	return 0;
}


int
read_3Dev( hid_device* dev) {
	unsigned char buf[ BUFLEN];
	int len;
	while ((len = hid_read( dev, buf, BUFLEN)) > 0) {
/*		Print raw data:
		printf( "hid_read() len=%d\n", len);
		for (int i = 0; i < len; ++i) {
			printf( "%02x ", buf[ i]);
		}
		printf( "\n");
*/
		// buf[ 0] == 1 => Translate, 2 => Rotate, 3 => Button event.
		if ((buf[ 0] == 1 || buf[ 0] == 2) && len == 7) {
			// Values are in the range -2595..2595.
			int16_t x_value = buf[ 1] | buf[ 2] << 8;
			int16_t y_value = buf[ 3] | buf[ 4] << 8;
			int16_t z_value = buf[ 5] | buf[ 6] << 8;
			printf( "%s X=%5d   Y=%5d   Z=%5d\n",
				buf[ 0] == 1 ? "Translate:" : "Rotate:   ",
				x_value, y_value, z_value);
		}
		if (buf[ 0] == 3 && len == 3) {
			// Is either 0, 1 or 2.
			uint16_t buttons = buf[ 1] | buf[ 2] << 8;
			printf( "Button: %x", buttons);
			// There is no way to distinguish release of button 1 and 2!
			if (buttons == 0) {
				printf( " released.");
			} else {
				if ((buttons & 1) != 0) {
					printf( " left");
				}
				if ((buttons & 2) != 0) {
					printf( " right");
				}
				printf( " pressed.");
			}
			printf( "\n");
		}
	}
	return len;
}


int
poll_nonblocking( hid_device* dev) {
	if (hid_set_nonblocking( dev, 1) < 0) {
		return -1;
	}
	while (read_3Dev( dev) >= 0) {
		struct timespec schnarch = { 0, 100000000};
		while (nanosleep( &schnarch, &schnarch) < 0) {};
	}
	if (hid_set_nonblocking( dev, 0) < 0) {
		return -1;
	}
	return 0;
}


int
main( int argc, char* argv[]) {
	uint16_t vendor_id = VENDOR_ID;
	uint16_t product_id = PRODUCT_ID;
	if (argc > 1) {
		vendor_id = strtoul( argv[ 1], NULL, 0);
	}
	if (argc > 2) {
		product_id = strtoul( argv[ 2], NULL, 0);
	}
	printf( "vendor_id=0x%04x product_id=0x%04x\n", vendor_id, product_id);
	if (hid_init() < 0) {
		fprintf( stderr, "Can't hid_init().\n");
		return EXIT_FAILURE;
	}
	// Try a list of product IDs. But up to now I know of only one.
	hid_device* dev = hid_open( vendor_id, product_id, NULL);
	if (dev == NULL) {
		fprintf( stderr, "Can't open 3D device.\n");
		return EXIT_FAILURE;
	}
	if (print_dev_info( dev) < 0 || read_3Dev( dev) < 0) {
//	if (print_dev_info( dev) < 0 || poll_nonblocking( dev) < 0) {
		fprintf( stderr, "hid_error()=%ls\n", hid_error( dev));
		hid_close( dev);
		hid_exit();
		return EXIT_FAILURE;
	}
	hid_close( dev);
	hid_exit();
	return EXIT_SUCCESS;
}