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

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

#include "ui.h"
#include "dynarr.h"

static Display *dsp;
static Window win;
static int scr;
static unsigned long fg, bg;
static XSizeHints szhint;
static GC gc;

static Font freg, fital;

/* TODO: center menu on screen */

void
ui_init(int argc, char **argv)
{
	dsp = XOpenDisplay("");
	scr = DefaultScreen(dsp);
	fg = BlackPixel(dsp, scr);
	bg = WhitePixel(dsp, scr);

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

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

	/* TODO: replace with modern XSetWMProperties */
	char title[] = "xmenu";
	XSetStandardProperties(dsp, win, title, title,
		None, argv, argc, &szhint);

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

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

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

UiKey
xksym_to_uik(KeySym sym)
{
	switch (sym) {
	case XK_Escape: return UIK_ESCAPE;
	case XK_BackSpace: return UIK_BACKSPACE;
	case XK_Up: return UIK_UP;
	case XK_Down: return UIK_DOWN;
	case XK_Left: return UIK_LEFT;
	case XK_Right: return UIK_RIGHT;
	case XK_Return: return UIK_RETURN;
	case XK_Home: return UIK_HOME;
	case XK_End: return UIK_END;
	case XK_Page_Down: return UIK_PGDN;
	case XK_Page_Up: return UIK_PGUP;
	default: return UIK_UNKNOWN;
	}
}

int
ui_wait_event(UiEvent *e)
{
	XEvent ev;
	KeySym sym;
	XNextEvent(dsp, &ev);
	switch (ev.type) {
	case KeyPress:
		e->type = UI_KEY_DOWN;
		e->key.strn = XLookupString(&ev.xkey, e->key.str, 10, &sym, 0);
		e->key.key = xksym_to_uik(sym);
		return 1;
	case KeyRelease:
		e->type = UI_KEY_UP;
		e->key.strn = XLookupString(&ev.xkey, e->key.str, 10, &sym, 0);
		e->key.key = xksym_to_uik(sym);
		return 1;
	case Expose:
		e->type = UI_REDRAW;
		return 1;
	}
	fprintf(stderr, "[Unknown event %d]\n", ev.type);
	return 0;
}

void
ui_draw(Str input, int inpi, int seli, Str *optv, int optc)
{
	XWindowAttributes attr;
	XClearWindow(dsp, win);
	XGetWindowAttributes(dsp, win, &attr);

	/* draw input */

	XSetFont(dsp, gc, fital);
	XDrawString(dsp, win, gc, 16, 24, input.s, input.n);
	XFontStruct *f = XQueryFont(dsp, XGContextFromGC(gc));
	int w = XTextWidth(f, input.s, inpi);
	XDrawLine(dsp, win, gc, 16 + w, 24 - f->ascent, 16 + w, 24 + f->descent);

	/* draw options */

	XSetFont(dsp, gc, freg);
	for (int i = 0; i < optc; i++) {
		if (i == seli) {
			int w = XTextWidth(XQueryFont(dsp,
				XGContextFromGC(gc)),
				optv[i].s, optv[i].n);
			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].s, optv[i].n);
			XSetForeground(dsp, gc, fg);
		} else {
			XDrawString(dsp, win, gc,
				16, 48 + i * 24 + 8,
				optv[i].s, optv[i].n);
		}
	}
}

void
ui_fini(void)
{
	XUnloadFont(dsp, freg);
	XUnloadFont(dsp, fital);
	XFreeGC(dsp, gc);
	XDestroyWindow(dsp, win);
	XCloseDisplay(dsp);
}