#include <time.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#define IsTTYFunctionKey(keysym) (((keysym >= 0xff08) && (keysym <= 0xff1b)) || keysym == 0xffff)

/* internal state */
Window focused_window = None;
Window last_focused_window = None;

char *rfc3339_format_time(struct tm *time) {
	char *rfc3339 = malloc(sizeof(char) * 100);
	strftime(rfc3339, 100, "%Y-%m-%d %H:%M:%S", time);
	int tzd_sec = abs(timezone) / 60 / 60;
	int tzd_mon = abs(timezone) % 60;
	sprintf(rfc3339 + strlen(rfc3339), "%+03d:%02d", tzd_sec, tzd_mon);
	return rfc3339;
}

char *rfc3339_now_str() {
	time_t now_t = time(NULL);
	struct tm *now = gmtime(&now_t);
	return rfc3339_format_time(now);
}

Window wparent(Display *display, Window window) {
	Window parent;
	Window root;
	Window *children;
	unsigned int nchildren;
	XQueryTree(display, window, &root, &parent, &children, &nchildren);
	return parent;
}

XTextProperty *get_window_name(Display *display, Window window) {
	XTextProperty *wm_name_prop = malloc(sizeof(XTextProperty));
	Atom net_wm_name = XInternAtom(display, "_NET_WM_NAME", False);
	XGetTextProperty(display, window, wm_name_prop, net_wm_name);
	if (wm_name_prop->value == NULL) {
		XGetTextProperty(display, wparent(display, window), wm_name_prop, net_wm_name);
	}
	return wm_name_prop;
}

void print_focus() { printf("%ld %ld\n", last_focused_window, focused_window); }
void print_title(Display *display) {
	XTextProperty *wm_name_prop = get_window_name(display, focused_window);
	printf("focus '%s' %s\n", wm_name_prop->value, rfc3339_now_str());
	free(wm_name_prop);
}
void print_key(XEvent ev) {
	KeyCode kc= -1;
	KeySym ksym;
	char *ksymname = NULL;
	char *kname = malloc(sizeof(char) * 2);

	XLookupString(&ev.xkey, kname, 2, &ksym, 0);

	/* Find out string representation */
	if(ksym == NoSymbol) {
		ksymname = "NoSymbol";
	} else {
		if (!(ksymname = XKeysymToString (ksym))) {
			ksymname = "(no name)";
		}
		kc = XKeysymToKeycode(ev.xany.display, ksym);
	}
	
	if (ksymname != NULL) {
		const int non_printable = IsKeypadKey(ksym) || IsTTYFunctionKey(ksym) || IsFunctionKey(ksym) || IsCursorKey(ksym) || IsModifierKey(ksym);
		printf("key ");
		if (non_printable) {
			printf("%s", ksymname);
		} else {
			printf("'%s'", kname);
		}
		printf(" %s\n", rfc3339_now_str());
	}
}

void setup(Display *display) {
	int _ignore; Window window;
	XGetInputFocus(display, &window, &_ignore);
	XSelectInput(display, window, KeyPressMask | FocusChangeMask | PropertyChangeMask);
}

void unfocus(Display *display) {
	if (focused_window != None) {
		last_focused_window = focused_window;
		focused_window = None;
	}
}

void refocus(Display *display) {
	int _ignore;
	XGetInputFocus(display, &focused_window, &_ignore);
	assert(focused_window != None);
}

void print_next_event(Display *display) {
	setup(display); XGetInputFocus(display, &focused_window, malloc(sizeof(int)));
	XEvent ev; XNextEvent(display, &ev);
	Atom _NET_WM_NAME = XInternAtom(display, "_NET_WM_NAME", False);
	
	if (ev.xany.type == FocusOut) {
		unfocus(display);
	} else if ((ev.xany.type == PropertyNotify && ev.xproperty.atom == _NET_WM_NAME)
			|| (ev.xany.type == FocusIn)) {
		refocus(display);
		print_title(display);
	} else if (ev.xany.type == KeyPress) {
		print_key(ev);
	}
}