/* Pango
 * pango-ot-tag.h:
 *
 * Copyright (C) 2007 Red Hat Software
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <config.h>

#include "pango-ot.h"

/*
 * complete list at:
 * http://www.microsoft.com/typography/developers/opentype/scripttags.aspx
 */
static const char ot_scripts[][4] = {
  "DFLT",	/* PANGO_SCRIPT_COMMON */
  "DFLT",	/* PANGO_SCRIPT_INHERITED */
  "arab",	/* PANGO_SCRIPT_ARABIC */
  "armn",	/* PANGO_SCRIPT_ARMENIAN */
  "beng",	/* PANGO_SCRIPT_BENGALI */
  "bopo",	/* PANGO_SCRIPT_BOPOMOFO */
  "cher",	/* PANGO_SCRIPT_CHEROKEE */
  "copt",	/* PANGO_SCRIPT_COPTIC */
  "cyrl",	/* PANGO_SCRIPT_CYRILLIC */
  "dsrt",	/* PANGO_SCRIPT_DESERET */
  "deva",	/* PANGO_SCRIPT_DEVANAGARI */
  "ethi",	/* PANGO_SCRIPT_ETHIOPIC */
  "geor",	/* PANGO_SCRIPT_GEORGIAN */
  "goth",	/* PANGO_SCRIPT_GOTHIC */
  "grek",	/* PANGO_SCRIPT_GREEK */
  "gujr",	/* PANGO_SCRIPT_GUJARATI */
  "guru",	/* PANGO_SCRIPT_GURMUKHI */
  "hani",	/* PANGO_SCRIPT_HAN */
  "hang",	/* PANGO_SCRIPT_HANGUL */
  "hebr",	/* PANGO_SCRIPT_HEBREW */
  "kana",	/* PANGO_SCRIPT_HIRAGANA */
  "knda",	/* PANGO_SCRIPT_KANNADA */
  "kana",	/* PANGO_SCRIPT_KATAKANA */
  "khmr",	/* PANGO_SCRIPT_KHMER */
  "lao ",	/* PANGO_SCRIPT_LAO */
  "latn",	/* PANGO_SCRIPT_LATIN */
  "mlym",	/* PANGO_SCRIPT_MALAYALAM */
  "mong",	/* PANGO_SCRIPT_MONGOLIAN */
  "mymr",	/* PANGO_SCRIPT_MYANMAR */
  "ogam",	/* PANGO_SCRIPT_OGHAM */
  "ital",	/* PANGO_SCRIPT_OLD_ITALIC */
  "orya",	/* PANGO_SCRIPT_ORIYA */
  "runr",	/* PANGO_SCRIPT_RUNIC */
  "sinh",	/* PANGO_SCRIPT_SINHALA */
  "syrc",	/* PANGO_SCRIPT_SYRIAC */
  "taml",	/* PANGO_SCRIPT_TAMIL */
  "telu",	/* PANGO_SCRIPT_TELUGU */
  "thaa",	/* PANGO_SCRIPT_THAANA */
  "thai",	/* PANGO_SCRIPT_THAI */
  "tibt",	/* PANGO_SCRIPT_TIBETAN */
  "cans",	/* PANGO_SCRIPT_CANADIAN_ABORIGINAL */
  "yi  ",	/* PANGO_SCRIPT_YI */
  "tglg",	/* PANGO_SCRIPT_TAGALOG */
  "hano",	/* PANGO_SCRIPT_HANUNOO */
  "buhd",	/* PANGO_SCRIPT_BUHID */
  "tagb",	/* PANGO_SCRIPT_TAGBANWA */
  "brai",	/* PANGO_SCRIPT_BRAILLE */
  "cprt",	/* PANGO_SCRIPT_CYPRIOT */
  "limb",	/* PANGO_SCRIPT_LIMBU */
  "osma",	/* PANGO_SCRIPT_OSMANYA */
  "shaw",	/* PANGO_SCRIPT_SHAVIAN */
  "linb",	/* PANGO_SCRIPT_LINEAR_B */
  "tale",	/* PANGO_SCRIPT_TAI_LE */
  "ugar",	/* PANGO_SCRIPT_UGARITIC */
  "talu",	/* PANGO_SCRIPT_NEW_TAI_LUE */
  "bugi",	/* PANGO_SCRIPT_BUGINESE */
  "glag",	/* PANGO_SCRIPT_GLAGOLITIC */
  "tfng",	/* PANGO_SCRIPT_TIFINAGH */
  "sylo",	/* PANGO_SCRIPT_SYLOTI_NAGRI */
  "xpeo",	/* PANGO_SCRIPT_OLD_PERSIAN */
  "khar",	/* PANGO_SCRIPT_KHAROSHTHI */
  "DFLT",	/* PANGO_SCRIPT_UNKNOWN */
  "bali",	/* PANGO_SCRIPT_BALINESE */
  "xsux",	/* PANGO_SCRIPT_CUNEIFORM */
  "phnx",	/* PANGO_SCRIPT_PHOENICIAN */
  "phag",	/* PANGO_SCRIPT_PHAGS_PA */
  "nko "	/* PANGO_SCRIPT_NKO */
};

/**
 * pango_ot_tag_from_script:
 * @script: A #PangoScript
 *
 * Finds the OpenType script tag corresponding to @script.
 *
 * The %PANGO_SCRIPT_COMMON, %PANGO_SCRIPT_INHERITED, and
 * %PANGO_SCRIPT_UNKNOWN scripts are mapped to the OpenType
 * 'DFLT' script tag that is also defined as
 * %PANGO_OT_TAG_DEFAULT_SCRIPT.
 *
 * Note that multiple #PangoScript values may map to the same
 * OpenType script tag.  In particular, %PANGO_SCRIPT_HIRAGANA
 * and %PANGO_SCRIPT_KATAKANA both map to the OT tag 'kana'.
 *
 * Return value: #PangoOTTag corresponding to @script or
 * %PANGO_OT_TAG_DEFAULT_SCRIPT if none found.
 *
 * Since: 1.18
 **/
PangoOTTag
pango_ot_tag_from_script (PangoScript script)
{
  g_return_val_if_fail (script >= 0 && (guint)script < G_N_ELEMENTS (ot_scripts), PANGO_OT_TAG_DEFAULT_SCRIPT);

  return GUINT32_FROM_BE (* (PangoOTTag *) ot_scripts[script]);
}

/**
 * pango_ot_tag_to_script:
 * @script_tag: A #PangoOTTag OpenType script tag
 *
 * Finds the #PangoScript corresponding to @script_tag.
 *
 * The 'DFLT' script tag is mapped to %PANGO_SCRIPT_COMMON.
 *
 * Note that an OpenType script tag may correspond to multiple
 * #PangoScript values.  In such cases, the #PangoScript value
 * with the smallest value is returned.
 * In particular, %PANGO_SCRIPT_HIRAGANA
 * and %PANGO_SCRIPT_KATAKANA both map to the OT tag 'kana'.
 * This function will return %PANGO_SCRIPT_HIRAGANA for
 * 'kana'.
 *
 * Return value: #PangoScript corresponding to @script_tag or
 * %PANGO_SCRIPT_UNKNOWN if none found.
 *
 * Since: 1.18
 **/
PangoScript
pango_ot_tag_to_script (PangoOTTag script_tag)
{
  PangoScript i;
  guint32 be_tag = GUINT32_TO_BE (script_tag);

  for (i = 0; i < (PangoScript) G_N_ELEMENTS (ot_scripts); i++)
    {
      guint32 tag = * (guint32 *) ot_scripts[i];

      if (tag == be_tag)
        return i;
    }

  return PANGO_SCRIPT_UNKNOWN;
}


typedef struct {
  char language[6];
  char tag[4];
} LangTag;

/*
 * complete list at:
 * http://www.microsoft.com/OpenType/OTSpec/languagetags.htm
 *
 * Generated by intersecting the above list with the ISO 639-2 codes
 * and then adjusting manually.  A lot of items missing still, feel
 * free to add.  Keep sorted for bsearch purpose.
 */
static const LangTag ot_languages[] = {
  {"aa",	"AFR "},
  {"ab",	"ABK "},
  {"ady",	"ADY "},
  {"af",	"AFK "},
  {"am",	"AMH "},
  {"ar",	"ARA "},
  {"as",	"ASM "},
  {"awa",	"AWA "},
  {"ay",	"AYM "},
  {"az",	"AZE "},
  {"ba",	"BSH "},
  {"bal",	"BLI "},
  {"bem",	"BEM "},
  {"ber",	"BBR "},
  {"bg",	"BGR "},
  {"bho",	"BHO "},
  {"bik",	"BIK "},
  {"bin",	"EDO "},
  {"bm",	"BMB "},
  {"bn",	"BEN "},
  {"bo",	"TIB "},
  {"br",	"BRE "},
  {"brh",	"BRH "},
  {"ca",	"CAT "},
  {"ce",	"CHE "},
  {"ceb",	"CEB "},
  {"chp",	"CHP "},
  {"chr",	"CHR "},
  {"cop",	"COP "},
  {"cr",	"CRE "},
  {"crh",	"CRT "},
  {"cs",	"CSY "},
  {"cu",	"CSL "},
  {"cv",	"CHU "},
  {"cy",	"WEL "},
  {"da",	"DAN "},
  {"dar",	"DAR "},
  {"de",	"DEU "},
  {"din",	"DNK "},
  {"doi",	"DGR "},
  {"dsb",	"LSB "},
  {"dv",	"DHV "},
  {"dz",	"DZN "},
  {"ee",	"EWE "},
  {"efi",	"EFI "},
  {"el",	"ELL "},
  {"en",	"ENG "},
  {"eo",	"NTO "},
  {"es",	"ESP "},
  {"et",	"ETI "},
  {"eu",	"EUQ "},
  {"fa",	"FAR "},
  {"ff",	"FUL "},
  {"fi",	"FIN "},
  {"fil",	"PIL "},
  {"fj",	"FJI "},
  {"fo",	"FOS "},
  {"fon",	"FON "},
  {"fr",	"FRA "},
  {"fur",	"FRL "},
  {"fy",	"FRI "},
  {"ga",	"IRI "},
  {"gaa",	"GAD "},
  {"gd",	"GAE "},
  {"gl",	"GAL "},
  {"gn",	"GUA "},
  {"gon",	"GON "},
  {"gu",	"GUJ "},
  {"ha",	"HAU "},
  {"he",	"IWR "},
  {"hi",	"HIN "},
  {"hil",	"HIL "},
  {"hr",	"HRV "},
  {"hsb",	"USB "},
  {"ht",	"HAI "},
  {"hu",	"HUN "},
  {"hy",	"HYE "},
  {"id",	"IND "},
  {"ig",	"IBO "},
  {"inc",	"SRK "},
  {"ine",	"KHW "},
  {"inh",	"ING "},
  {"is",	"ISL "},
  {"it",	"ITA "},
  {"iu",	"INU "},
  {"ja",	"JAN "},
  {"jv",	"JAV "},
  {"ka",	"KAT "},
  {"kam",	"KMB "},
  {"kbd",	"KAB "},
  {"kha",	"KSI "},
  {"ki",	"KIK "},
  {"kk",	"KAZ "},
  {"kl",	"GRN "},
  {"km",	"KHM "},
  {"kn",	"KAN "},
  {"ko",	"KOR "},
  {"kok",	"KOK "},
  {"kpe",	"KPL "},
  {"kr",	"KNR "},
  {"krl",	"KRL "},
  {"kru",	"KUU "},
  {"ks",	"KSH "},
  {"ku",	"KUR "},
  {"kum",	"KUM "},
  {"ky",	"KIR "},
  {"la",	"LAT "},
  {"lad",	"JUD "},
  {"lbj",	"LDK "},
  {"ln",	"LIN "},
  {"lo",	"LAO "},
  {"lt",	"LTH "},
  {"lv",	"LVI "},
  {"mai",	"MTH "},
  {"mdf",	"MOK "},
  {"men",	"MDE "},
  {"mg",	"MLG "},
  {"mi",	"MRI "},
  {"mkh",	"KUY "},
  {"ml",	"MLR "},
  {"mnc",	"MCH "},
  {"mni",	"MNI "},
  {"mnk",	"MND "},
  {"mo",	"MOL "},
  {"mr",	"MAR "},
  {"ms",	"MLY "},
  {"mt",	"MTS "},
  {"mwr",	"MAW "},
  {"my",	"BRM "},
  {"myv",	"ERZ "},
  {"ne",	"NEP "},
  {"nl",	"NLD "},
  {"no",	"NOR "},
  {"ny",	"CHI "},
  {"oc",	"PRO "},
  {"om",	"ORO "},
  {"or",	"ORI "},
  {"os",	"OSS "},
  {"pa",	"PAN "},
  {"pi",	"PAL "},
  {"pl",	"PLK "},
  {"ps",	"PAS "},
  {"pt",	"PTG "},
  {"ro",	"ROM "},
  {"rom",	"ROY "},
  {"ru",	"RUS "},
  {"sa",	"SAN "},
  {"sat",	"SAT "},
  {"sd",	"SND "},
  {"sel",	"SEL "},
  {"sg",	"SGO "},
  {"shn",	"SHN "},
  {"si",	"SNH "},
  {"sid",	"SID "},
  {"sk",	"SKY "},
  {"sl",	"SLV "},
  {"sm",	"SMO "},
  {"smj",	"LSM "},
  {"smn",	"ISM "},
  {"sms",	"SKS "},
  {"snk",	"SNK "},
  {"so",	"SML "},
  {"sq",	"SQI "},
  {"sr",	"SRB "},
  {"srr",	"SRR "},
  {"sv",	"SVE "},
  {"sw",	"SWK "},
  {"syr",	"SYR "},
  {"ta",	"TAM "},
  {"te",	"TEL "},
  {"tg",	"TAJ "},
  {"th",	"THA "},
  {"ti",	"TGY "},
  {"tig",	"TGR "},
  {"tk",	"TKM "},
  {"tn",	"TNA "},
  {"tr",	"TRK "},
  {"ts",	"TSG "},
  {"tw",	"TWI "},
  {"udm",	"UDM "},
  {"ug",	"UYG "},
  {"uk",	"UKR "},
  {"ur",	"URD "},
  {"uz",	"UZB "},
  {"ve",	"VEN "},
  {"vi",	"VIT "},
  {"wo",	"WLF "},
  {"xal",	"KLM "},
  {"xh",	"XHS "},
  {"yi",	"JII "},
  {"yo",	"YBA "},
  {"zh-cn",	"ZHS "},
  {"zh-hk",	"ZHH "},
  {"zh-mo",	"ZHT "},
  {"zh-sg",	"ZHS "},
  {"zh-tw",	"ZHT "},
  {"zu",	"ZUL "}
};

static int
lang_compare_first_component (gconstpointer pa,
			      gconstpointer pb)
{
  const char *a = pa, *b = pb;
  unsigned int da, db;
  const char *p;

  p = strstr (a, "-");
  da = p ? (unsigned int) (p - a) : strlen (a);

  p = strstr (b, "-");
  db = p ? (unsigned int) (p - b) : strlen (b);
   
  return strncmp (a, b, MAX (da, db));
}

/**
 * pango_ot_tag_from_language:
 * @language: A #PangoLanguage, or %NULL
 *
 * Finds the OpenType language-system tag best describing @language.
 *
 * Return value: #PangoOTTag best matching @language or
 * %PANGO_OT_TAG_DEFAULT_LANGUAGE if none found or if @language
 * is %NULL.
 *
 * Since: 1.18
 **/
PangoOTTag
pango_ot_tag_from_language (PangoLanguage *language)
{
  const char *lang_str;
  LangTag *lang_tag;

  if (language == NULL)
    return PANGO_OT_TAG_DEFAULT_LANGUAGE;

  lang_str = pango_language_to_string (language);

  /* find a language matching in the first component */
  lang_tag = bsearch (lang_str, ot_languages,
		      G_N_ELEMENTS (ot_languages), sizeof (LangTag),
		      lang_compare_first_component);

  /* we now need to find the best language matching */
  if (lang_tag)
    {
      gboolean found = FALSE;

      /* go to the final one matching in the first component */
      while (lang_tag + 1 < ot_languages + G_N_ELEMENTS (ot_languages) &&
	     lang_compare_first_component (lang_str, lang_tag + 1) == 0)
        lang_tag++;

      /* go back, find which one matches completely */
      while (lang_tag >= ot_languages &&
	     lang_compare_first_component (lang_str, lang_tag) == 0)
        {
	  if (pango_language_matches (language, lang_tag->language))
	    {
	      found = TRUE;
	      break;
	    }

          lang_tag--;
	}

      if (!found)
        lang_tag = NULL;
    }

  if (lang_tag)
    return GUINT32_FROM_BE (* (PangoOTTag *) lang_tag->tag);

  return PANGO_OT_TAG_DEFAULT_LANGUAGE;
}

/**
 * pango_ot_tag_to_language:
 * @language_tag: A #PangoOTTag OpenType language-system tag
 *
 * Finds a #PangoLanguage corresponding to @language_tag.
 *
 * Return value: #PangoLanguage best matching @language_tag or
 * #PangoLanguage corresponding to the string "xx" if none found.
 *
 * Since: 1.18
 **/
PangoLanguage *
pango_ot_tag_to_language (PangoOTTag language_tag)
{
  int i;
  guint32 be_tag = GUINT32_TO_BE (language_tag);

  for (i = 0; i < (int) G_N_ELEMENTS (ot_languages); i++)
    {
      guint32 tag = * (guint32 *) ot_languages[i].tag;

      if (tag == be_tag)
        return pango_language_from_string (ot_languages[i].language);
    }

  return pango_language_from_string ("xx");
}