/* See LICENSE file for copyright and license details. */

#include <locale.h>

#include <stdarg.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <X11/Xlib.h>

#include "draw.h"

#define MAX(a, b)  ((a) > (b) ? (a) : (b))

#define MIN(a, b)  ((a) < (b) ? (a) : (b))

#define DEFAULTFN  "fixed"

static Bool loadfont(DC *dc, const char *fontstr);

void

drawrect(DC *dc, int x, int y, unsigned int w, unsigned int h, Bool fill, unsigned long color) {

	XSetForeground(dc->dpy, dc->gc, color);

	if(fill)

		XFillRectangle(dc->dpy, dc->canvas, dc->gc, dc->x + x, dc->y + y, w, h);

	else

		XDrawRectangle(dc->dpy, dc->canvas, dc->gc, dc->x + x, dc->y + y, w-1, h-1);

}

void

drawtext(DC *dc, const char *text, unsigned long col[ColLast]) {

	char buf[BUFSIZ];

	size_t mn, n = strlen(text);

	/* shorten text if necessary */

	for(mn = MIN(n, sizeof buf); textnw(dc, text, mn) + dc->font.height/2 > dc->w; mn--)

		if(mn == 0)

			return;

	memcpy(buf, text, mn);

	if(mn < n)

		for(n = MAX(mn-3, 0); n < mn; buf[n++] = '.');

	drawrect(dc, 0, 0, dc->w, dc->h, True, BG(dc, col));

	drawtextn(dc, buf, mn, col);

}

void

drawtextn(DC *dc, const char *text, size_t n, unsigned long col[ColLast]) {

	int x = dc->x + dc->font.height/2;

	int y = dc->y + dc->font.ascent+1;

	XSetForeground(dc->dpy, dc->gc, FG(dc, col));

	if(dc->font.set)

		XmbDrawString(dc->dpy, dc->canvas, dc->font.set, dc->gc, x, y, text, n);

	else {

		XSetFont(dc->dpy, dc->gc, dc->font.xfont->fid);

		XDrawString(dc->dpy, dc->canvas, dc->gc, x, y, text, n);

	}

}

void

eprintf(const char *fmt, ...) {

	va_list ap;

	va_start(ap, fmt);

	vfprintf(stderr, fmt, ap);

	va_end(ap);

	if(fmt[0] != '\0' && fmt[strlen(fmt)-1] == ':') {

		fputc(' ', stderr);

		perror(NULL);

	}

	exit(EXIT_FAILURE);

}

void

freedc(DC *dc) {

	if(dc->font.set)

		XFreeFontSet(dc->dpy, dc->font.set);

	if(dc->font.xfont)

		XFreeFont(dc->dpy, dc->font.xfont);

	if(dc->canvas)

		XFreePixmap(dc->dpy, dc->canvas);

	XFreeGC(dc->dpy, dc->gc);

	XCloseDisplay(dc->dpy);

	free(dc);

}

unsigned long

getcolor(DC *dc, const char *colstr) {

	Colormap cmap = DefaultColormap(dc->dpy, DefaultScreen(dc->dpy));

	XColor color;

	if(!XAllocNamedColor(dc->dpy, cmap, colstr, &color, &color))

		eprintf("cannot allocate color '%s'\n", colstr);

	return color.pixel;

}

DC *

initdc(void) {

	DC *dc;

	if(!setlocale(LC_CTYPE, "") || !XSupportsLocale())

		fprintf(stderr, "no locale support\n");

	if(!(dc = calloc(1, sizeof *dc)))

		eprintf("cannot malloc %u bytes:", sizeof *dc);

	if(!(dc->dpy = XOpenDisplay(NULL)))

		eprintf("cannot open display\n");

	dc->gc = XCreateGC(dc->dpy, DefaultRootWindow(dc->dpy), 0, NULL);

	XSetLineAttributes(dc->dpy, dc->gc, 1, LineSolid, CapButt, JoinMiter);

	return dc;

}

void

initfont(DC *dc, const char *fontstr) {

	if(!loadfont(dc, fontstr ? fontstr : DEFAULTFN)) {

		if(fontstr != NULL)

			fprintf(stderr, "cannot load font '%s'\n", fontstr);

		if(fontstr == NULL || !loadfont(dc, DEFAULTFN))

			eprintf("cannot load font '%s'\n", DEFAULTFN);

	}

	dc->font.height = dc->font.ascent + dc->font.descent;

}

Bool

loadfont(DC *dc, const char *fontstr) {

	char *def, **missing, **names;

	int i, n = 1;

	XFontStruct **xfonts;

	if(!*fontstr)

		return False;

	if((dc->font.set = XCreateFontSet(dc->dpy, fontstr, &missing, &n, &def))) {

		n = XFontsOfFontSet(dc->font.set, &xfonts, &names);

	}

	else {

		dc->font.xfont = XLoadQueryFont(dc->dpy, fontstr);

		xfonts = &dc->font.xfont;

	}

	for(i = 0; i < n; i++) {

		dc->font.ascent  = MAX(dc->font.ascent,  xfonts[i]->ascent);

		dc->font.descent = MAX(dc->font.descent, xfonts[i]->descent);

		dc->font.width   = MAX(dc->font.width,   xfonts[i]->max_bounds.width);

	}

	if(missing)

		XFreeStringList(missing);

	return (dc->font.set || dc->font.xfont);

}

void

mapdc(DC *dc, Window win, unsigned int w, unsigned int h) {

	XCopyArea(dc->dpy, dc->canvas, win, dc->gc, 0, 0, w, h, 0, 0);

}

void

resizedc(DC *dc, unsigned int w, unsigned int h) {

	if(dc->canvas)

		XFreePixmap(dc->dpy, dc->canvas);

	dc->canvas = XCreatePixmap(dc->dpy, DefaultRootWindow(dc->dpy), w, h,

	                           DefaultDepth(dc->dpy, DefaultScreen(dc->dpy)));

	dc->w = w;

	dc->h = h;

}

int

textnw(DC *dc, const char *text, size_t len) {

	if(dc->font.set) {

		XRectangle r;

		XmbTextExtents(dc->font.set, text, len, NULL, &r);

		return r.width;

	}

	return XTextWidth(dc->font.xfont, text, len);

}

int

textw(DC *dc, const char *text) {

	return textnw(dc, text, strlen(text)) + dc->font.height;

}

/* See LICENSE file for copyright and license details. */

#define FG(dc, col)  ((col)[(dc)->invert ? ColBG : ColFG])

#define BG(dc, col)  ((col)[(dc)->invert ? ColFG : ColBG])

enum { ColBG, ColFG, ColBorder, ColLast };

typedef struct {

	int x, y, w, h;

	Bool invert;

	Display *dpy;

	GC gc;

	Pixmap canvas;

	struct {

		int ascent;

		int descent;

		int height;

		int width;

		XFontSet set;

		XFontStruct *xfont;

	} font;

} DC;  /* draw context */

void drawrect(DC *dc, int x, int y, unsigned int w, unsigned int h, Bool fill, unsigned long color);

void drawtext(DC *dc, const char *text, unsigned long col[ColLast]);

void drawtextn(DC *dc, const char *text, size_t n, unsigned long col[ColLast]);

void eprintf(const char *fmt, ...);

void freedc(DC *dc);

unsigned long getcolor(DC *dc, const char *colstr);

DC *initdc(void);

void initfont(DC *dc, const char *fontstr);

void mapdc(DC *dc, Window win, unsigned int w, unsigned int h);

void resizedc(DC *dc, unsigned int w, unsigned int h);

int textnw(DC *dc, const char *text, size_t len);

int textw(DC *dc, const char *text);