/* See LICENSE file for copyright and license details. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/Xft/Xft.h>

#include "drw.h"
#include "util.h"

#define UTF_INVALID 0xFFFD

Drw *
drw_create(Display *dpy, int screen, Window root, unsigned int w, unsigned int h)
{
	Drw *drw = ecalloc(1, sizeof(Drw));

	drw->dpy = dpy;
	drw->screen = screen;
	drw->root = root;
	drw->w = w;
	drw->h = h;
	drw->drawable = XCreatePixmap(dpy, root, w, h, DefaultDepth(dpy, screen));
	drw->gc = XCreateGC(dpy, root, 0, NULL);
	XSetLineAttributes(dpy, drw->gc, 1, LineSolid, CapButt, JoinMiter);

	return drw;
}

void
drw_resize(Drw *drw, unsigned int w, unsigned int h)
{
	if (!drw)
		return;

	drw->w = w;
	drw->h = h;
	if (drw->drawable)
		XFreePixmap(drw->dpy, drw->drawable);
	drw->drawable = XCreatePixmap(drw->dpy, drw->root, w, h, DefaultDepth(drw->dpy, drw->screen));
}

void
drw_free(Drw *drw)
{
	XFreePixmap(drw->dpy, drw->drawable);
	XFreeGC(drw->dpy, drw->gc);
	drw_fontset_free(drw->fonts);
	free(drw);
}

/* This function is an implementation detail. Library users should use
 * drw_fontset_create instead.
 */
static Fnt *
xfont_create(Drw *drw, const char *fontname, FcPattern *fontpattern)
{
	Fnt *font;
	XftFont *xfont = NULL;
	FcPattern *pattern = NULL;

	if (fontname) {
		/* Using the pattern found at font->xfont->pattern does not yield the
		 * same substitution results as using the pattern returned by
		 * FcNameParse; using the latter results in the desired fallback
		 * behaviour whereas the former just results in missing-character
		 * rectangles being drawn, at least with some fonts. */
		if (!(xfont = XftFontOpenName(drw->dpy, drw->screen, fontname))) {
			fprintf(stderr, "error, cannot load font from name: '%s'\n", fontname);
			return NULL;
		}
		if (!(pattern = FcNameParse((FcChar8 *) fontname))) {
			fprintf(stderr, "error, cannot parse font name to pattern: '%s'\n", fontname);
			XftFontClose(drw->dpy, xfont);
			return NULL;
		}
	} else if (fontpattern) {
		if (!(xfont = XftFontOpenPattern(drw->dpy, fontpattern))) {
			fprintf(stderr, "error, cannot load font from pattern.\n");
			return NULL;
		}
	} else {
		die("no font specified.");
	}

	font = ecalloc(1, sizeof(Fnt));
	font->xfont = xfont;
	font->pattern = pattern;
	font->h = xfont->ascent + xfont->descent;
	font->dpy = drw->dpy;

	return font;
}

static void
xfont_free(Fnt *font)
{
	if (!font)
		return;
	if (font->pattern)
		FcPatternDestroy(font->pattern);
	XftFontClose(font->dpy, font->xfont);
	free(font);
}

Fnt*
drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount)
{
	Fnt *cur, *ret = NULL;
	size_t i;

	if (!drw || !fonts)
		return NULL;

	for (i = 1; i <= fontcount; i++) {
		if ((cur = xfont_create(drw, fonts[fontcount - i], NULL))) {
			cur->next = ret;
			ret = cur;
		}
	}
	return (drw->fonts = ret);
}

void
drw_fontset_free(Fnt *font)
{
	if (font) {
		drw_fontset_free(font->next);
		xfont_free(font);
	}
}

void
drw_clr_create(Drw *drw, Clr *dest, const char *clrname)
{
	if (!drw || !dest || !clrname)
		return;

	if (!XftColorAllocName(drw->dpy, DefaultVisual(drw->dpy, drw->screen),
	                       DefaultColormap(drw->dpy, drw->screen),
	                       clrname, dest))
		die("error, cannot allocate color '%s'", clrname);

	dest->pixel |= 0xff << 24;
}

/* Wrapper to create color schemes. The caller has to call free(3) on the
 * returned color scheme when done using it. */
Clr *
drw_scm_create(Drw *drw, const char *clrnames[], size_t clrcount)
{
	size_t i;
	Clr *ret;

	/* need at least two colors for a scheme */
	if (!drw || !clrnames || clrcount < 2 || !(ret = ecalloc(clrcount, sizeof(XftColor))))
		return NULL;

	for (i = 0; i < clrcount; i++)
		drw_clr_create(drw, &ret[i], clrnames[i]);
	return ret;
}

void
drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h)
{
	XGlyphInfo ext;

	if (!font || !text)
		return;

	XftTextExtentsUtf8(font->dpy, font->xfont, (XftChar8 *)text, len, &ext);
	if (w)
		*w = ext.xOff;
	if (h)
		*h = font->h;
}

Cur *
drw_cur_create(Drw *drw, int shape)
{
	Cur *cur;

	if (!drw || !(cur = ecalloc(1, sizeof(Cur))))
		return NULL;

	cur->cursor = XCreateFontCursor(drw->dpy, shape);

	return cur;
}

void
drw_cur_free(Drw *drw, Cur *cursor)
{
	if (!cursor)
		return;

	XFreeCursor(drw->dpy, cursor->cursor);
	free(cursor);
}