#include <stdint.h>
#include <stdio.h>
#include <time.h>

#include <iostream>
#include <thread>

#include <QWidget>
#include <QApplication>

#include "hidapi.h"
#include "SpaceNav.h"
#include "printutils.h"


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


using namespace std;




const QEvent::Type SpaceNavEvent::my_type = static_cast< QEvent::Type>( QEvent::registerEventType());




static void
sleep_iter( void) {
	struct timespec schnarch = { 1, 0};
	while (nanosleep( &schnarch, &schnarch) < 0) {};
}




class SpaceNav::Impl {

private:
	hid_device* dev;

public:
	Impl( SpaceNav& parent); 
	void operator()( void);

private:
	SpaceNav& parent;

};


SpaceNav::Impl::Impl( SpaceNav& p) :
	parent( p) { 
}


void
SpaceNav::Impl::operator()( void) {
	if (hid_init() < 0) {
		PRINTD( "Can't hid_init().\n");
		return;
	}
	uint16_t buttons = 0;
	for (;; sleep_iter()) {
		// Try a list of product IDs. But up to now I know of only one.
		dev = hid_open( VENDOR_ID, PRODUCT_ID, NULL);
		if (dev == NULL) {
			PRINTD( "Can't open 3D device.\n");
			continue;
		}
		unsigned char buf[ BUFLEN];
		int len;
		while ((len = hid_read( dev, buf, BUFLEN)) > 0) {
			// QWidget* widget = QApplication::focusWidget(); doesn't do the tric.
			QWidget* widget = QApplication::activeWindow();
			if (widget == 0) {
				continue;
			}
			QEvent* event = 0;
			if ((buf[ 0] == 1 || buf[ 0] == 2) && len == 7) {
				// Values are in the range -10..10 at min. speed and -2595..2595 at max. speed.
				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;
				if (buf[ 0] == 1) {
					event = new SpaceNavEventTranslate( x_value, y_value, z_value);
				} else {
					event = new SpaceNavEventRotate( x_value, y_value, z_value);
				}
			}
			if (buf[ 0] == 3 && len == 3) {
				// Is either 0, 1 or 2.
				uint16_t bitmask = buf[ 1] | buf[ 2] << 8;
				uint16_t down = ~buttons & bitmask;
				uint16_t up = buttons & ~bitmask;
				buttons = bitmask;
				event = new SpaceNavEventButton( down, up); 
			}
			if (event != 0) {
				QCoreApplication::postEvent( widget, event);
			}
		}
		hid_close( dev);
	}
}





SpaceNav::SpaceNav( void) :
	pimpl_thread( NULL) {
};


void
SpaceNav::operator()( void) {
	pimpl_thread = new std::thread( Impl( *this));
	pimpl_thread->detach();
};


SpaceNav::~SpaceNav( void) {
	if (pimpl_thread != NULL) {
		delete pimpl_thread;
	}
};


SpaceNav spacenav;