#include <X11/Xos.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

/* "borrowed" from xwininfo/dsimple.c */

/*
 * Found this code on
 * https://stackoverflow.com/questions/1028972/x11-raise-an-existing-window-via-command-line
 */

static Window Window_With_Name(Display *dpy, Window top, char *name);

int
main(int argc, char **argv)
{
	Window window;
	Display *dpy;

	if (argc < 2) {
		fprintf(stderr, "Usage: %s window-name\n", argv[0]);
		exit(1);
	}

	dpy = XOpenDisplay(":0");
	if (!dpy) {
		fprintf(stderr, "Cannot open display.\n");
		exit(1);
	}

	window = Window_With_Name(dpy, DefaultRootWindow(dpy), argv[1]);
	if (!window) {
		fprintf(stderr, "Cannot find a window by that name.\n");
		exit(1);
	}

	if (!XRaiseWindow(dpy, window)) {
		fprintf(stderr, "XRaiseWindow error?\n");
		exit(1);
	}

	XCloseDisplay(dpy);
	exit(0);
}

static Window
Window_With_Name(Display *dpy, Window top, char *name)
{
	Window *children, dummy;
	unsigned int nchildren;
	int i;
	Window w = 0;
	char *window_name;

	if (XFetchName(dpy, top, &window_name) && (strstr(window_name, name)))
		return top;

	if (!XQueryTree(dpy, top, &dummy, &dummy, &children, &nchildren))
		return 0;

	for (i = 0; i < nchildren; i++) {
		w = Window_With_Name(dpy, children[i], name);
		if (w)
			break;
	}
	if (children)
		XFree((char *)children);

	return w;
}