#include <X11/Xlib.h>
#include <X11/extensions/Xrandr.h>
#include <stdlib.h>
#include <stdio.h>

Display *dpy;
Rotation r = 0;

void rotate() {
	Rotation old_r = r;
	char buf[256];
	char *r_name;

	XRRRotations(dpy, DefaultScreen(dpy), &r);
	if (old_r == r)
		return;
	switch (r) {
		case RR_Rotate_0:
			r_name = "none";
			break;
		case RR_Rotate_90:
			r_name = "ccw";
			break;
		case RR_Rotate_180:
			r_name = "half";
			break;
		case RR_Rotate_270:
			r_name = "cw";
			break;
		default:
			return;
	}
	snprintf(buf, 255, "xsetwacom set stylus rotate %s", r_name);
	system(buf);
}

int main(int argc, char *argv[]) {
	XEvent ev;
	int event_basep;
	int error_basep;

	dpy = XOpenDisplay(NULL); //TODO
	if (!dpy) {
		fprintf(stderr, "Couldn't open display\n");
		exit(-1);
	}

	if (!XRRQueryExtension(dpy, &event_basep, &error_basep)) {
		fprintf(stderr, "RandR not available\n");
		exit(-1);
	}

	XRRSelectInput(dpy, DefaultRootWindow(dpy), RRScreenChangeNotifyMask);

	while (1) {
		XNextEvent(dpy, &ev);
		if (ev.type == event_basep) {
			XRRUpdateConfiguration(&ev);
			rotate();
		}
	}
}