/* xmenu
 * a simple fuzzy-selection menu made with Xlib
 */

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/XKBlib.h>
#include <stdio.h>

#define ARENA_IMPL
#define STR_IMPL

#include "arena.h"
#include "dynarr.h"
#include "str.h"

typedef DYNARR(char) DynStr;

int
umod(int a, int b)
{
	if (a < 0) {
		return b + a % b;
	} else {
		return a % b;
	}
}

int
main(int argc, char **argv)
{
	Display *dsp = XOpenDisplay("");
	int scr = DefaultScreen(dsp);
	unsigned long fg = BlackPixel(dsp, scr);
	unsigned long bg = WhitePixel(dsp, scr);

	XSizeHints szhint = { 0 };
	szhint.width = 350;
	szhint.height = 250;
	szhint.flags = PSize;

	Window win = XCreateSimpleWindow(
		dsp,
		DefaultRootWindow(dsp),
		szhint.x, szhint.y,
		szhint.width, szhint.height,
		5 /* border width */,
		fg, bg);

	char title[] = "xmenu";
	XSetStandardProperties(dsp, win, title, title,
		None, argv, argc, &szhint);

	GC gc = XCreateGC(dsp, win, 0, 0);
	XSetBackground(dsp, gc, bg);
	XSetForeground(dsp, gc, fg);

	XSelectInput(dsp, win, ButtonPressMask | KeyPressMask | ExposureMask);
	XMapRaised(dsp, win);

	Font freg = XLoadFont(dsp, "-*-new century schoolbook-medium-r-*-*-24-*-*-*-*-*-*-*");
	Font fital = XLoadFont(dsp, "-*-new century schoolbook-medium-i-*-*-24-*-*-*-*-*-*-*");

	/* see Xft(3) */

	DynStr input = { 0 };

	int seli = 0;

	const char *optv[] = { "she shit on my thang until i vomit", "what", "who are you", "why are you", "where'd you come from" };
	int optc = sizeof optv / sizeof *optv;

	for (;;) {
		XEvent ev;
		KeySym key;
		XNextEvent(dsp, &ev);
		switch (ev.type) {
		case KeyPress: {
			char kbuf[32];
			KeyCode kc = ev.xkey.keycode;
			KeySym sym = XkbKeycodeToKeysym(dsp, kc, 0,
				!!(ev.xkey.state & ShiftMask));
			int rune = ksym_to_unicode(sym);
			switch (sym) {
			case XK_Escape:
				goto done;
			case XK_BackSpace:
				if (input.n > 0) input.n--;
				goto draw;
			case XK_Return:
				input.n = 0;
				goto draw;
			case XK_Down:
				seli = umod(seli + 1, optc);
				goto draw;
			case XK_Up:
				seli = umod(seli - 1, optc);
				goto draw;
			default: {
				int n = XLookupString(&ev.xkey, kbuf, 10, &key, 0);
				if (!n) break;
				DA_PUSH_MULT(&input, kbuf, n);
				seli = 0;
				goto draw;
			} break;
			}
		} break;
		case Expose: {
		draw:;
			XWindowAttributes attr;
			XClearWindow(dsp, win);
			XGetWindowAttributes(dsp, win, &attr);
			//XGetSizeHints(dsp, win, &szhint);
			XSetFont(dsp, gc, fital);
			int w = XTextWidth(XQueryFont(dsp, XGContextFromGC(gc)), input.v, input.n);
			DA_PUSH(&input, '_');
			XDrawString(dsp, win, gc, 16, 24, input.v, input.n);
			input.n--;
			XSetFont(dsp, gc, freg);
			for (int i = 0; i < optc; i++) {
				if (i == seli) {
					int w = XTextWidth(XQueryFont(dsp,
						XGContextFromGC(gc)),
						optv[i], strlen(optv[i]));
					XFillRectangle(dsp, win, gc,
						16, 28 + i * 24 + 8,
						w, 24);
					XSetForeground(dsp, gc, bg);
					XDrawString(dsp, win, gc,
						16, 48 + i * 24 + 8,
						optv[i], strlen(optv[i]));
					XSetForeground(dsp, gc, fg);
				} else {
					XDrawString(dsp, win, gc,
						16, 48 + i * 24 + 8,
						optv[i], strlen(optv[i]));
				}

			}
		} break;
		/* TODO: figure out quit events */
		}
	}

done:	;

	XUnloadFont(dsp, freg);
	XUnloadFont(dsp, fital);
	XFreeGC(dsp, gc);
	XDestroyWindow(dsp, win);
	XCloseDisplay(dsp);

	return 0;
}