#define _E_FONT_C_

/*
 * e-font
 *
 * Temporary wrappers around GdkFonts to get unicode displaying
 *
 * Author: Lauris Kaplinski <lauris@helixcode.com>
 *
 * Copyright (C) 2000 Helix Code, Inc.
 *
 * TODO: LRU Cache
 *
 */

#include <string.h>
#include <gdk/gdkx.h>
#include <unicode.h>
#include "e-font.h"

#define FONT_TESTING

struct _EFont {
	gint refcount;
	GdkFont *font;
	GdkFont *bold;
	gboolean twobyte;
	unicode_iconv_t to;
	unicode_iconv_t from;
};

static gboolean find_variants (gchar **namelist, gint length,
			       gchar *base_weight, gchar **light,
			       gchar **bold);

EFont *
e_font_from_gdk_name (const gchar *name)
{
	EFont * font;
	GdkFont *gdkfont;

	gdkfont = gdk_font_load (name);
	font = e_font_from_gdk_font (gdkfont);
	gdk_font_unref (gdkfont);

	return font;
}

EFont *
e_font_from_gdk_font (GdkFont *gdkfont)
{
	EFont *font;
	XFontStruct *xfs;
	Atom font_atom, atom;
	Bool status;
	GdkFont *boldfont, *lightfont;

	boldfont = lightfont = NULL;

	gdk_font_ref (gdkfont);

	/* Try to find iso-10646-1 encoded font with same name */

	font_atom = gdk_atom_intern ("FONT", FALSE);
	if (gdkfont->type == GDK_FONT_FONTSET) {
		XFontStruct **font_structs;
		gint num_fonts;
		gchar **font_names;
		num_fonts = XFontsOfFontSet (GDK_FONT_XFONT (gdkfont),
					     &font_structs,
					     &font_names);
		status = XGetFontProperty (font_structs[0],
					   font_atom,
					   &atom);
	} else {
		status = XGetFontProperty (GDK_FONT_XFONT (gdkfont),
					   font_atom,
					   &atom);
	}
	if (status) {
		gchar *c[14];
		gchar *name, *p;
		gchar *enc, *boldname, *lightname;
		gchar **namelist;
		GdkFont *newfont;
		gint numfonts, len, i;

		name = gdk_atom_name (atom);
		len = strlen (name) + 64; /* Hope that's sufficent */
		p = name;

		for (i = 0; i < 13; i++) {
			c[i] = p;
			/* Skip text */
			while (*p && (*p != '-')) p++;
			/* Replace hyphen with '\0' */
			if (*p) *p++ = '\0';
		}
		c[i] = p;

		p = alloca (len);

		/* Compose name for unicode encoding */
		enc = "iso10646-1";
		g_snprintf (p, len, "%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s",
			    c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7],
			    c[8], c[9], c[10], c[11], c[12], enc);
		/* Try to load unicode font */
		newfont = gdk_font_load (p);
		if (newfont) {
			/* OK, use that */
			gdk_font_unref (gdkfont);
			gdkfont = newfont;
		} else {
			/* Nope, use original encoding */
			enc = c[13];
		}
		/* Try to find bolder variant */
		g_snprintf (p, len, "%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s",
			    c[0], c[1], c[2], "*", c[4], c[5], "*", "*",
			    c[8], c[9], c[10], c[11], "*", enc);
		namelist = XListFonts (GDK_FONT_XDISPLAY (gdkfont),
				       p, 32, &numfonts);
		if (find_variants (namelist, numfonts, c[3],
				   &lightname, &boldname)) {
			if (!g_strcasecmp (c[3], lightname))
				lightfont = gdkfont;
			else if (!g_strcasecmp (c[3], boldname))
				boldfont = gdkfont;
			else
				gdk_font_unref (gdkfont);

			if (!lightfont) {
				g_snprintf (p, len, "%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s",
					    c[0], c[1], c[2], lightname, c[4],
					    c[5], "*", "*", c[8], c[9], c[10],
					    c[11], "*", enc);
				lightfont = gdk_font_load (p);
			}
			if (!boldfont) {
				g_snprintf (p, len, "%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s",
					    c[0], c[1], c[2], boldname, c[4],
					    c[5], "*", "*", c[8], c[9], c[10],
					    c[11], "*", enc);
				boldfont = gdk_font_load (p);
			}
		} else
			lightfont = gdkfont;
		XFreeFontNames (namelist);

		g_free (name);
	}

	font = g_new (EFont, 1);

	xfs = GDK_FONT_XFONT (gdkfont);

	font->refcount = 1;
	font->font = lightfont;
	font->bold = boldfont;
	font->twobyte = ((xfs->min_byte1 != 0) || (xfs->max_byte1 != 0));
	font->to = e_uiconv_to_gdk_font (font->font);
	font->from = e_uiconv_from_gdk_font (font->font);

	return font;

}

void
e_font_ref (EFont *font)
{
	font->refcount++;
}

void
e_font_unref (EFont *font)
{
	font->refcount--;

	if (font->refcount < 1) {
		gdk_font_unref (font->font);
		if (font->bold) gdk_font_unref (font->bold);
		g_free (font);
	}
}

gint
e_font_ascent (EFont * font)
{
	return font->font->ascent;
}

gint
e_font_descent (EFont * font)
{
	return font->font->descent;
}

static gint
e_font_to_native (EFont *font, gchar *native, gchar *utf, gint bytes)
{
	char *ib, *ob;
	size_t ibl, obl;

	ib = utf;
	ibl = bytes;
	ob = native;
	obl = bytes * 4;

	while (ibl > 0) {
		unicode_iconv (font->to, (const char **) &ib, &ibl, &ob, &obl);
		if (ibl > 0) {
			gint len;
			if ((*ib & 0x80) == 0x00) len = 1;
			else if ((*ib &0xe0) == 0xc0) len = 2;
			else if ((*ib &0xf0) == 0xe0) len = 3;
			else if ((*ib &0xf80) == 0xf0) len = 4;
			else {
				g_warning ("Invalid UTF-8 sequence");
				return ob - native;
			}
			ib += len;
			ibl = bytes - (ib - utf);
			if (ibl > bytes) ibl = 0;
			if (!font->twobyte) {
				*ob++ = '_';
				obl--;
			} else {
				*((guint16 *) ob) = '_';
				ob += 2;
				obl -= 2;
			}
		}
	}

	return ob - native;
}

void
e_font_draw_utf8_text (GdkDrawable *drawable, EFont *font, EFontStyle style, GdkGC *gc, gint x, gint y, gchar *text, gint numbytes)
{
	gchar *native;
	gint native_bytes;

	g_return_if_fail (drawable != NULL);
	g_return_if_fail (font != NULL);
	g_return_if_fail (gc != NULL);
	g_return_if_fail (text != NULL);

	if (numbytes < 1) return;

	native = alloca (numbytes * 4);

	native_bytes = e_font_to_native (font, native, text, numbytes);

	if ((style & E_FONT_BOLD) && (font->bold)) {
		gdk_draw_text (drawable, font->bold, gc, x, y, native, native_bytes);
	} else {
		gdk_draw_text (drawable, font->font, gc, x, y, native, native_bytes);
		if (style & E_FONT_BOLD)
			gdk_draw_text (drawable, font->font, gc, x + 1, y, native, native_bytes);
	}
}

gint
e_font_utf8_text_width (EFont *font, EFontStyle style, char *text, int numbytes)
{
	gchar *native;
	gint native_bytes;
	gint width;

	g_return_val_if_fail (font != NULL, 0);
	g_return_val_if_fail (text != NULL, 0);

	if (numbytes < 1) return 0;

	native = alloca (numbytes * 4);

	native_bytes = e_font_to_native (font, native, text, numbytes);

	if ((style & E_FONT_BOLD) && (font->bold)) {
		width = gdk_text_width (font->bold, native, native_bytes);
	} else {
		width = gdk_text_width (font->font, native, native_bytes);
	}

	return width;
}

gint
e_font_utf8_char_width (EFont *font, EFontStyle style, char *text)
{
	gint len;

	g_return_val_if_fail (font != NULL, 0);
	g_return_val_if_fail (text != NULL, 0);

	if ((*text & 0x80) == 0x00) len = 1;
	else if ((*text &0xe0) == 0xc0) len = 2;
	else if ((*text &0xf0) == 0xe0) len = 3;
	else if ((*text &0xf80) == 0xf0) len = 4;
	else {
		g_warning ("Invalid UTF-8 sequence");
		return 0;
	}

	return e_font_utf8_text_width (font, style, text, len);
}

static const gchar *
translate_encoding (const gchar *encoding)
{
	static GHashTable *eh = NULL;
	gchar e[64];

	if (!eh) {
		eh = g_hash_table_new (g_str_hash, g_str_equal);

		g_hash_table_insert (eh, "iso8859-1", "iso-8859-1");
		g_hash_table_insert (eh, "iso8859-2", "iso-8859-2");
		g_hash_table_insert (eh, "iso8859-3", "iso-8859-3");
		g_hash_table_insert (eh, "iso8859-4", "iso-8859-4");
		g_hash_table_insert (eh, "iso8859-5", "iso-8859-5");
		g_hash_table_insert (eh, "iso8859-6", "iso-8859-6");
		g_hash_table_insert (eh, "iso8859-7", "iso-8859-7");
		g_hash_table_insert (eh, "iso8859-8", "iso-8859-8");
		g_hash_table_insert (eh, "iso8859-9", "iso-8859-9");
		g_hash_table_insert (eh, "iso8859-10", "iso-8859-10");
		g_hash_table_insert (eh, "iso8859-13", "iso-8859-13");
		g_hash_table_insert (eh, "iso8859-14", "iso-8859-14");
		g_hash_table_insert (eh, "iso8859-15", "iso-8859-15");
		g_hash_table_insert (eh, "iso10646-1", "UTF-16");
		g_hash_table_insert (eh, "koi8-r", "koi8-r");
	}

	strncpy (e, encoding, 64);
	g_strdown (e);

	return g_hash_table_lookup (eh, e);
}

const gchar *
e_gdk_font_encoding (GdkFont *font)
{
	Atom font_atom, atom;
	Bool status;
	char *name, *p;
	const gchar *encoding;
	gint i;

	if (!font) return NULL;

	font_atom = gdk_atom_intern ("FONT", FALSE);

	if (font->type == GDK_FONT_FONTSET) {
		XFontStruct **font_structs;
		gint num_fonts;
		gchar **font_names;

		num_fonts = XFontsOfFontSet (GDK_FONT_XFONT (font),
					     &font_structs,
					     &font_names);
		status = XGetFontProperty (font_structs[0],
					   font_atom,
					   &atom);
	} else {
		status = XGetFontProperty (GDK_FONT_XFONT (font),
					   font_atom,
					   &atom);
	}

	if (!status) return NULL;

	name = p = gdk_atom_name (atom);

	for (i = 0; i < 13; i++) {
		/* Skip hyphen */
		while (*p && (*p != '-')) p++;
		if (*p) p++;
	}

	if (!*p) return NULL;

	encoding = translate_encoding (p);

	g_free (name);

	return encoding;
}

unicode_iconv_t
e_uiconv_from_gdk_font (GdkFont *font)
{
	static GHashTable *uh = NULL;
	const gchar *enc;
	unicode_iconv_t uiconv;

	if (!font) return (unicode_iconv_t) -1;

	enc = e_gdk_font_encoding (font);

	if (!enc) return (unicode_iconv_t) -1;

	if (!uh) uh = g_hash_table_new (g_str_hash, g_str_equal);

	uiconv = g_hash_table_lookup (uh, enc);

	if (!uiconv) {
		uiconv = unicode_iconv_open ("UTF-8", enc);
		if (uiconv == (unicode_iconv_t) -1) return uiconv;
		g_hash_table_insert (uh, (gpointer) enc, uiconv);
	}

	return uiconv;
}

unicode_iconv_t
e_uiconv_to_gdk_font (GdkFont *font)
{
	static GHashTable *uh = NULL;
	const gchar *enc;
	unicode_iconv_t uiconv;

	if (!font) return (unicode_iconv_t) -1;

	enc = e_gdk_font_encoding (font);

	if (!enc) return (unicode_iconv_t) -1;

	if (!uh) uh = g_hash_table_new (g_str_hash, g_str_equal);

	uiconv = g_hash_table_lookup (uh, enc);

	if (!uiconv) {
		uiconv = unicode_iconv_open (enc, "UTF-8");
		if (uiconv == (unicode_iconv_t) -1) return uiconv;
		g_hash_table_insert (uh, (gpointer) enc, uiconv);
	}

	return uiconv;
}

/* Find light and bold variants of a font, ideally using the provided
 * weight for the light variant, and a weight 2 shades darker than it
 * for the bold variant. If there isn't something 2 shades darker, use
 * something 3 or more shades darker if it exists, or 1 shade darker
 * if that's all there is. If there is nothing darker than the provided
 * weight, but there are lighter fonts, then use the darker one for
 * bold and a lighter one for light.
 */
static gboolean
find_variants (gchar **namelist, gint length, gchar *weight,
	       gchar **lightname, gchar **boldname)
{
	static GHashTable *wh = NULL;
	/* Standard, Found, Bold, Light */
	gint sw, fw, bw, lw;
	gchar *s, *f, *b, *l = NULL;
	gchar *p;
	gint i;

	if (!wh) {
		wh = g_hash_table_new (g_str_hash, g_str_equal);
		g_hash_table_insert (wh, "light", GINT_TO_POINTER (1));
		g_hash_table_insert (wh, "book", GINT_TO_POINTER (2));
		g_hash_table_insert (wh, "regular", GINT_TO_POINTER (2));
		g_hash_table_insert (wh, "medium", GINT_TO_POINTER (3));
		g_hash_table_insert (wh, "demibold", GINT_TO_POINTER (5));
		g_hash_table_insert (wh, "bold", GINT_TO_POINTER (6));
		g_hash_table_insert (wh, "black", GINT_TO_POINTER (8));
	}

	s = alloca (strlen (weight) + 1);
	strcpy (s, weight);
	g_strdown (s);
	sw = GPOINTER_TO_INT (g_hash_table_lookup (wh, s));
	if (sw == 0) return FALSE;

	fw = 0; lw = 0; bw = 32;
	f = NULL; b = NULL;
	*lightname = NULL; *boldname = NULL;

	for (i = 0; i < length; i++) {
		p = namelist[i];
		if (*p) p++;
		while (*p && (*p != '-')) p++;
		if (*p) p++;
		while (*p && (*p != '-')) p++;
		if (*p) p++;
		f = p;
		while (*p && (*p != '-')) p++;
		if (*p) *p = '\0';
		g_strdown (f);
		fw = GPOINTER_TO_INT (g_hash_table_lookup (wh, f));
		if (fw) {
			if (fw > sw) {
				if ((fw - 2 == sw) ||
				    ((fw > bw) && (bw == sw + 1)) ||
				    ((fw < bw) && (fw - 2 > sw))) {
					bw = fw;
					b = f;
				}
			} else if (fw < sw) {
				if ((fw + 2 == sw) ||
				    ((fw < lw) && (lw == sw - 1)) ||
				    ((fw > lw) && (fw + 2 < sw))) {
					lw = fw;
					l = f;
				}
			}
		}
	}

	if (b) {
		*lightname = weight;
		*boldname = b;
		return TRUE;
	} else if (l) {
		*lightname = l;
		*boldname = weight;
		return TRUE;
	}
	return FALSE;
}