/* See LICENSE file for copyright and license details. */
#include <ctype.h>
#include <locale.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <X11/Xlib.h>
#include "draw.h"

/* macros */
#define MIN(a, b)               ((a) < (b) ? (a) : (b))
#define MAX(a, b)               ((a) > (b) ? (a) : (b))

void
drawcleanup(void) {
	if(dc.font.set)
		XFreeFontSet(dpy, dc.font.set);
	else
		XFreeFont(dpy, dc.font.xfont);
	XFreePixmap(dpy, dc.drawable);
	XFreeGC(dpy, dc.gc);
}

void
drawsetup(void) {
	/* style */
	dc.norm[ColBG] = getcolor(normbgcolor);
	dc.norm[ColFG] = getcolor(normfgcolor);
	dc.sel[ColBG] = getcolor(selbgcolor);
	dc.sel[ColFG] = getcolor(selfgcolor);

	/* pixmap */
	dc.drawable = XCreatePixmap(dpy, parent, mw, mh, DefaultDepth(dpy, screen));
	dc.gc = XCreateGC(dpy, parent, 0, NULL);
	XSetLineAttributes(dpy, dc.gc, 1, LineSolid, CapButt, JoinMiter);
	if(!dc.font.set)
		XSetFont(dpy, dc.gc, dc.font.xfont->fid);
}

void
drawtext(const char *text, unsigned long col[ColLast]) {
	char buf[256];
	int i, x, y, h, len, olen;
	XRectangle r = { dc.x, dc.y, dc.w, dc.h };

	XSetForeground(dpy, dc.gc, col[ColBG]);
	XFillRectangles(dpy, dc.drawable, dc.gc, &r, 1);
	if(!text)
		return;
	olen = strlen(text);
	h = dc.font.height;
	y = dc.y + ((h+2) / 2) - (h / 2) + dc.font.ascent;
	x = dc.x + (h / 2);
	/* shorten text if necessary */
	for(len = MIN(olen, sizeof buf); len && textnw(text, len) > dc.w - h; len--);
	if(!len)
		return;
	memcpy(buf, text, len);
	if(len < olen)
		for(i = len; i && i > len - 3; buf[--i] = '.');
	XSetForeground(dpy, dc.gc, col[ColFG]);
	if(dc.font.set)
		XmbDrawString(dpy, dc.drawable, dc.font.set, dc.gc, x, y, buf, len);
	else
		XDrawString(dpy, dc.drawable, dc.gc, x, y, buf, len);
}

void
eprint(const char *errstr, ...) {
	va_list ap;

	va_start(ap, errstr);
	vfprintf(stderr, errstr, ap);
	va_end(ap);
	exit(EXIT_FAILURE);
}

unsigned long
getcolor(const char *colstr) {
	Colormap cmap = DefaultColormap(dpy, screen);
	XColor color;

	if(!XAllocNamedColor(dpy, cmap, colstr, &color, &color))
		eprint("drawtext: cannot allocate color '%s'\n", colstr);
	return color.pixel;
}

void
initfont(const char *fontstr) {
	char *def, **missing = NULL;
	int i, n;

	if(!fontstr || fontstr[0] == '\0')
		eprint("drawtext: cannot load font: '%s'\n", fontstr);
	dc.font.set = XCreateFontSet(dpy, fontstr, &missing, &n, &def);
	if(missing)
		XFreeStringList(missing);
	if(dc.font.set) {
		XFontStruct **xfonts;
		char **font_names;
		dc.font.ascent = dc.font.descent = 0;
		n = XFontsOfFontSet(dc.font.set, &xfonts, &font_names);
		for(i = 0; i < n; i++) {
			dc.font.ascent = MAX(dc.font.ascent, (*xfonts)->ascent);
			dc.font.descent = MAX(dc.font.descent, (*xfonts)->descent);
			xfonts++;
		}
	}
	else {
		if(!(dc.font.xfont = XLoadQueryFont(dpy, fontstr))
		&& !(dc.font.xfont = XLoadQueryFont(dpy, "fixed")))
			eprint("drawtext: cannot load font: '%s'\n", fontstr);
		dc.font.ascent = dc.font.xfont->ascent;
		dc.font.descent = dc.font.xfont->descent;
	}
	dc.font.height = dc.font.ascent + dc.font.descent;
}

int
textnw(const char *text, unsigned int len) {
	XRectangle r;

	if(dc.font.set) {
		XmbTextExtents(dc.font.set, text, len, NULL, &r);
		return r.width;
	}
	return XTextWidth(dc.font.xfont, text, len);
}

int
textw(const char *text) {
	return textnw(text, strlen(text)) + dc.font.height;
}