#include <iostream>
#include <functional>
#include <X11/XKBlib.h>
#include "xutil.h"


namespace x {

	Keycode Keysym::toCode(Display *dpy) const {
		return XKeysymToKeycode(dpy, sym);
	}

	void bel(Display *dpy) {
		XkbBell(dpy, None, 100, None);
	}

	using UponExitF = UponExit<std::function<void()>>;

	UponExitF XGrabKeyRAII(Display *dpy, Keycode code, int modifier, Window win) {
		XGrabKey(dpy, (unsigned int)code, modifier, win, False, GrabModeAsync, GrabModeAsync);
		return UponExitF{[dpy, code, modifier, win]() {
			XUngrabKey(dpy, (unsigned int)code, modifier, win);
			XSync(dpy, False);
		}};
	}

	UponExitF XGrabKeyboardRAII(Display *dpy, Window win) {
		int ret = XGrabKeyboard(dpy, win, False, GrabModeAsync, GrabModeAsync, CurrentTime);
		if (ret == AlreadyGrabbed) {
			XUngrabKeyboard(dpy, CurrentTime);
			XSync(dpy, False);
			throw std::runtime_error("Cannot grab keyboard: already grabbed");
		}
		return UponExitF{[dpy]() {
			XUngrabKeyboard(dpy, CurrentTime);
			XSync(dpy, False);
		}};
	}

	std::pair<Display*, UponExitF> XOpenDisplayRAII(const char *name) {
		Display *dpy = XOpenDisplay(name);
		if (dpy == nullptr) {
			std::cerr << "Cannot open X display" << std::endl;
			exit(1);
		}
		return std::make_pair(dpy, UponExitF{[dpy]() {
			XCloseDisplay(dpy);
		}});
	}

	void globalKeyWatch(Display *dpy, Keysym keysym, std::function<bool(const XKeyEvent&)> callback) {
		globalKeyWatch(dpy, keysym.toCode(dpy), callback);
	}

	void globalKeyWatch(Display *dpy, Keycode keycode, std::function<bool(const XKeyEvent&)> callback) {
		const Window root = DefaultRootWindow(dpy);

		auto guard = XGrabKeyRAII(dpy, keycode, AnyModifier, root);

		XSelectInput(dpy, root, KeyPressMask);
		while (true) {
			XEvent ev;
			XNextEvent(dpy, &ev);
			if (ev.type == KeyPress && ev.xkey.keycode == (unsigned int)keycode) {
				if (callback(ev.xkey)) return;
			}
		}
	}

	void globalKeyboardGrab(Display *dpy, std::function<bool(const XKeyEvent&)> callback) {
		const Window root = DefaultRootWindow(dpy);

		try {
			auto guard = XGrabKeyboardRAII(dpy, root);

			while (true) {
				XEvent ev;
				XNextEvent(dpy, &ev);
				if (ev.type == KeyPress) {
					if (callback(ev.xkey)) return;
				}
			}
		} catch (std::exception &e) {
			std::cerr << e.what() << std::endl;
		}
	}

}