/**
 * @file llfindlocale.cpp
 * @brief Detect system language setting
 *
 * $LicenseInfo:firstyear=2008&license=viewergpl$
 *
 * Copyright (c) 2008-2009, Linden Research, Inc.
 *
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 *
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 *
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 *
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

// NOTE: this file used to be in llcommon/, but is only used in newview/ (i.e.
// it is not used by SLPlugin or other llcommon.a consummers), and is best
// placed together with the keyboard and display related sources. HB

#if LL_WINDOWS
# include "llwin32headers.h"
#endif

#include "linden_common.h"

#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "llfindlocale.h"

static void lang_country_variant_from_envstring(const char* str, char** lang,
												char** country, char** variant)
{
	int end = 0;
	int start;

	// Get lang, if any
	start = end;
	while (isalnum(str[end]))
	{
		++end;
	}

	if (start != end)
	{
    	int i;
	    int len = end - start;
    	char* s = (char*)malloc(len + 1);
		for (i = 0; i < len; ++i)
		{
			s[i] = tolower(str[start + i]);
		}
		s[i] = '\0';
		*lang = s;
	}
	else
	{
		*lang = NULL;
	}

	if (str[end] && str[end]!=':') // Not at end of st
	{
		++end;
	}

	// Get country, if any
	start = end;
	while (isalnum(str[end]))
	{
		++end;
	}
	if (start != end)
	{
		int i;
		int len = end - start;
		char* s = (char*)malloc(len + 1);
		for (i = 0; i < len; ++i)
		{
			s[i] = toupper(str[start + i]);
		}
		s[i] = '\0';
		*country = s;
	}
	else
	{
	*country = NULL;
	}

	if (str[end] && str[end]!=':')	// Not at end of str
	{
		++end;
	}

	// Get variant, if any
	start = end;
	while (str[end] && str[end]!=':')
	{
		++end;
	}
	if (start != end)
	{
		int i;
		int len = end - start;
		char* s = (char*)malloc(len + 1);
		for (i = 0; i < len; ++i)
		{
			s[i] = str[start + i];
		}
		s[i] = '\0';
		*variant = s;
	}
	else
	{
		*variant = NULL;
	}
}

static int accumulate_locstring(const char* str, FL_Locale* l)
{
	char* lang = NULL;
	char* country = NULL;
	char* variant = NULL;
	if (str)
	{
		lang_country_variant_from_envstring(str, &lang, &country, &variant);
		if (lang)
		{
			l->lang = lang;
			l->country = country;
			l->variant = variant;
			return 1;
		}
	}
	free(lang);
	free(country);
	free(variant);
	return 0;
}

static int accumulate_env(const char* name, FL_Locale* l)
{
	char* lang = NULL;
	char* country = NULL;
	char* variant = NULL;
	char* env = getenv(name);
	if (env)
	{
		return accumulate_locstring(env, l);
	}
	free(lang);
	free(country);
	free(variant);
	return 0;
}

// This function fixes some common locale-specifying mistakes
static void canonise_fl(FL_Locale* l)
{
	// en_UK -> en_GB
	if (l->lang && 0 == strcmp(l->lang, "en"))
	{
		if (l->country && 0 == strcmp(l->country, "UK"))
		{
			free((void*)l->country);
			l->country = strdup("GB");
		}
	}
	// ja_JA -> ja_JP */
	if (l->lang && 0 == strcmp(l->lang, "ja"))
	{
		if (l->country && 0 == strcmp(l->country, "JA"))
		{
			free((void*)l->country);
			l->country = strdup("JP");
		}
	}
}

#ifdef WIN32
# include <stdio.h>
# define ML(pn,sn) MAKELANGID(LANG_##pn, SUBLANG_##pn##_##sn)
# define MLN(pn) MAKELANGID(LANG_##pn, SUBLANG_DEFAULT)
# define RML(pn,sn) MAKELANGID(LANG_##pn, SUBLANG_##sn)
struct IDToCode
{
  LANGID	id;
  char*		code;
};
static const IDToCode both_to_code[] =
{
	{ ML(ENGLISH,US),           "en_US.ISO_8859-1" },
	{ ML(ENGLISH,CAN),          "en_CA" },	// english / canadian
	{ ML(ENGLISH,UK),           "en_GB" },
	{ ML(ENGLISH,EIRE),         "en_IE" },
	{ ML(ENGLISH,AUS),          "en_AU" },
	{ MLN(GERMAN),              "de_DE" },
	{ MLN(SPANISH),             "es_ES" },
	{ ML(SPANISH,MEXICAN),      "es_MX" },
	{ MLN(FRENCH),              "fr_FR" },
	{ ML(FRENCH,CANADIAN),      "fr_CA" },
	{ ML(FRENCH,BELGIAN),       "fr_BE" },
	{ ML(DUTCH,BELGIAN),        "nl_BE" },
	{ ML(PORTUGUESE,BRAZILIAN), "pt_BR" },
	{ MLN(PORTUGUESE),          "pt_PT" },
	{ MLN(SWEDISH),             "sv_SE" },
	{ ML(CHINESE,HONGKONG),     "zh_HK" },
	// These are machine-generated and not yet verified
	{ RML(AFRIKAANS,DEFAULT), "af_ZA" },
	{ RML(ALBANIAN,DEFAULT), "sq_AL" },
	{ RML(ARABIC,ARABIC_ALGERIA), "ar_DZ" },
	{ RML(ARABIC,ARABIC_BAHRAIN), "ar_BH" },
	{ RML(ARABIC,ARABIC_EGYPT), "ar_EG" },
	{ RML(ARABIC,ARABIC_IRAQ), "ar_IQ" },
	{ RML(ARABIC,ARABIC_JORDAN), "ar_JO" },
	{ RML(ARABIC,ARABIC_KUWAIT), "ar_KW" },
	{ RML(ARABIC,ARABIC_LEBANON), "ar_LB" },
	{ RML(ARABIC,ARABIC_LIBYA), "ar_LY" },
	{ RML(ARABIC,ARABIC_MOROCCO), "ar_MA" },
	{ RML(ARABIC,ARABIC_OMAN), "ar_OM" },
	{ RML(ARABIC,ARABIC_QATAR), "ar_QA" },
	{ RML(ARABIC,ARABIC_SAUDI_ARABIA), "ar_SA" },
	{ RML(ARABIC,ARABIC_SYRIA), "ar_SY" },
	{ RML(ARABIC,ARABIC_TUNISIA), "ar_TN" },
	{ RML(ARABIC,ARABIC_UAE), "ar_AE" },
	{ RML(ARABIC,ARABIC_YEMEN), "ar_YE" },
	{ RML(ARMENIAN,DEFAULT), "hy_AM" },
	{ RML(AZERI,AZERI_CYRILLIC), "az_AZ" },
	{ RML(AZERI,AZERI_LATIN), "az_AZ" },
	{ RML(BASQUE,DEFAULT), "eu_ES" },
	{ RML(BELARUSIAN,DEFAULT), "be_BY" },
	//{RML(BRETON,DEFAULT), "br_FR" },
	{ RML(BULGARIAN,DEFAULT), "bg_BG" },
	{ RML(CATALAN,DEFAULT), "ca_ES" },
	{ RML(CHINESE,CHINESE_HONGKONG), "zh_HK" },
	{ RML(CHINESE,CHINESE_MACAU), "zh_MO" },
	{ RML(CHINESE,CHINESE_SIMPLIFIED), "zh_CN" },
	{ RML(CHINESE,CHINESE_SINGAPORE), "zh_SG" },
	{ RML(CHINESE,CHINESE_TRADITIONAL), "zh_TW" },
	//{RML(CORNISH,DEFAULT), "kw_GB" },
	{ RML(CZECH,DEFAULT), "cs_CZ" },
	{ RML(DANISH,DEFAULT), "da_DK" },
	{ RML(DUTCH,DUTCH), "nl_NL" },
	{ RML(DUTCH,DUTCH_BELGIAN), "nl_BE" },
	//{RML(DUTCH,DUTCH_SURINAM), "nl_SR" },
	{ RML(ENGLISH,ENGLISH_AUS), "en_AU" },
	{ RML(ENGLISH,ENGLISH_BELIZE), "en_BZ" },
	{ RML(ENGLISH,ENGLISH_CAN), "en_CA" },
	{ RML(ENGLISH,ENGLISH_CARIBBEAN), "en_CB" },
	{ RML(ENGLISH,ENGLISH_EIRE), "en_IE" },
	{ RML(ENGLISH,ENGLISH_JAMAICA), "en_JM" },
	{ RML(ENGLISH,ENGLISH_NZ), "en_NZ" },
	{ RML(ENGLISH,ENGLISH_PHILIPPINES), "en_PH" },
	{ RML(ENGLISH,ENGLISH_SOUTH_AFRICA), "en_ZA" },
	{ RML(ENGLISH,ENGLISH_TRINIDAD), "en_TT" },
	{ RML(ENGLISH,ENGLISH_UK), "en_GB" },
	{ RML(ENGLISH,ENGLISH_US), "en_US" },
	{ RML(ENGLISH,ENGLISH_ZIMBABWE), "en_ZW" },
	//{RML(ESPERANTO,DEFAULT), "eo_" },
	{ RML(ESTONIAN,DEFAULT), "et_EE" },
	{ RML(FAEROESE,DEFAULT), "fo_FO" },
	{ RML(FARSI,DEFAULT), "fa_IR" },
	{ RML(FINNISH,DEFAULT), "fi_FI" },
	{ RML(FRENCH,FRENCH), "fr_FR" },
	{ RML(FRENCH,FRENCH_BELGIAN), "fr_BE" },
	{ RML(FRENCH,FRENCH_CANADIAN), "fr_CA" },
	{ RML(FRENCH,FRENCH_LUXEMBOURG), "fr_LU" },
	{ RML(FRENCH,FRENCH_MONACO), "fr_MC" },
	{ RML(FRENCH,FRENCH_SWISS), "fr_CH" },
	//{RML(GAELIC,GAELIC), "ga_IE" },
	//{RML(GAELIC,GAELIC_MANX), "gv_GB" },
	//{RML(GAELIC,GAELIC_SCOTTISH), "gd_GB" },
	//{RML(GALICIAN,DEFAULT), "gl_ES" },
	{ RML(GEORGIAN,DEFAULT), "ka_GE" },
	{ RML(GERMAN,GERMAN), "de_DE" },
	{ RML(GERMAN,GERMAN_AUSTRIAN), "de_AT" },
	{ RML(GERMAN,GERMAN_LIECHTENSTEIN), "de_LI" },
	{ RML(GERMAN,GERMAN_LUXEMBOURG), "de_LU" },
	{ RML(GERMAN,GERMAN_SWISS), "de_CH" },
	{ RML(GREEK,DEFAULT), "el_GR" },
	{ RML(GUJARATI,DEFAULT), "gu_IN" },
	{ RML(HEBREW,DEFAULT), "he_IL" },
	{ RML(HINDI,DEFAULT), "hi_IN" },
	{ RML(HUNGARIAN,DEFAULT), "hu_HU" },
	{ RML(ICELANDIC,DEFAULT), "is_IS" },
	{ RML(INDONESIAN,DEFAULT), "id_ID" },
	{ RML(ITALIAN,ITALIAN), "it_IT" },
	{ RML(ITALIAN,ITALIAN_SWISS), "it_CH" },
	{ RML(JAPANESE,DEFAULT), "ja_JP" },
	{ RML(KANNADA,DEFAULT), "kn_IN" },
	{ RML(KAZAK,DEFAULT), "kk_KZ" },
	{ RML(KONKANI,DEFAULT), "kok_IN" },
	{ RML(KOREAN,KOREAN), "ko_KR" },
	//{RML(KYRGYZ,DEFAULT), "ky_KG" },
	{ RML(LATVIAN,DEFAULT), "lv_LV" },
	{ RML(LITHUANIAN,LITHUANIAN), "lt_LT" },
	{ RML(MACEDONIAN,DEFAULT), "mk_MK" },
	{ RML(MALAY,MALAY_BRUNEI_DARUSSALAM), "ms_BN" },
	{ RML(MALAY,MALAY_MALAYSIA), "ms_MY" },
	{ RML(MARATHI,DEFAULT), "mr_IN" },
	//{RML(MONGOLIAN,DEFAULT), "mn_MN" },
	{ RML(NORWEGIAN,NORWEGIAN_BOKMAL), "nb_NO" },
	{ RML(NORWEGIAN,NORWEGIAN_NYNORSK), "nn_NO" },
	{ RML(POLISH,DEFAULT), "pl_PL" },
	{ RML(PORTUGUESE,PORTUGUESE), "pt_PT" },
	{ RML(PORTUGUESE,PORTUGUESE_BRAZILIAN), "pt_BR" },
	{ RML(PUNJABI,DEFAULT), "pa_IN" },
	{ RML(ROMANIAN,DEFAULT), "ro_RO" },
	{ RML(RUSSIAN,DEFAULT), "ru_RU" },
	{ RML(SANSKRIT,DEFAULT), "sa_IN" },
	{ RML(SERBIAN,DEFAULT), "hr_HR" },
	{ RML(SERBIAN,SERBIAN_CYRILLIC), "sr_SP" },
	{ RML(SERBIAN,SERBIAN_LATIN), "sr_SP" },
	{ RML(SLOVAK,DEFAULT), "sk_SK" },
	{ RML(SLOVENIAN,DEFAULT), "sl_SI" },
	{ RML(SPANISH,SPANISH), "es_ES" },
	{ RML(SPANISH,SPANISH_ARGENTINA), "es_AR" },
	{ RML(SPANISH,SPANISH_BOLIVIA), "es_BO" },
	{ RML(SPANISH,SPANISH_CHILE), "es_CL" },
	{ RML(SPANISH,SPANISH_COLOMBIA), "es_CO" },
	{ RML(SPANISH,SPANISH_COSTA_RICA), "es_CR" },
	{ RML(SPANISH,SPANISH_DOMINICAN_REPUBLIC), "es_DO" },
	{ RML(SPANISH,SPANISH_ECUADOR), "es_EC" },
	{ RML(SPANISH,SPANISH_EL_SALVADOR), "es_SV" },
	{ RML(SPANISH,SPANISH_GUATEMALA), "es_GT" },
	{ RML(SPANISH,SPANISH_HONDURAS), "es_HN" },
	{ RML(SPANISH,SPANISH_MEXICAN), "es_MX" },
	{ RML(SPANISH,SPANISH_MODERN), "es_ES" },
	{ RML(SPANISH,SPANISH_NICARAGUA), "es_NI" },
	{ RML(SPANISH,SPANISH_PANAMA), "es_PA" },
	{ RML(SPANISH,SPANISH_PARAGUAY), "es_PY" },
	{ RML(SPANISH,SPANISH_PERU), "es_PE" },
	{ RML(SPANISH,SPANISH_PUERTO_RICO), "es_PR" },
	{ RML(SPANISH,SPANISH_URUGUAY), "es_UY" },
	{ RML(SPANISH,SPANISH_VENEZUELA), "es_VE" },
	{ RML(SWAHILI,DEFAULT), "sw_KE" },
	{ RML(SWEDISH,SWEDISH), "sv_SE" },
	{ RML(SWEDISH,SWEDISH_FINLAND), "sv_FI" },
	//{ RML(SYRIAC,DEFAULT), "syr_SY" },
	{ RML(TAMIL,DEFAULT), "ta_IN" },
	{ RML(TATAR,DEFAULT), "tt_TA" },
	{ RML(TELUGU,DEFAULT), "te_IN" },
	{ RML(THAI,DEFAULT), "th_TH" },
	{ RML(TURKISH,DEFAULT), "tr_TR" },
	{ RML(UKRAINIAN,DEFAULT), "uk_UA" },
	{ RML(URDU,URDU_PAKISTAN), "ur_PK" },
	{ RML(UZBEK,UZBEK_CYRILLIC), "uz_UZ" },
	{ RML(UZBEK,UZBEK_LATIN), "uz_UZ" },
	{ RML(VIETNAMESE,DEFAULT), "vi_VN" },
	//{RML(WALON,DEFAULT), "wa_BE" },
	//{RML(WELSH,DEFAULT), "cy_GB" },
};

static const IDToCode primary_to_code[] =
{
	{ LANG_AFRIKAANS,  "af" },
	{ LANG_ARABIC,     "ar" },
	{ LANG_AZERI,      "az" },
	{ LANG_BULGARIAN,  "bg" },
	//{ LANG_BRETON,     "br" },
	{ LANG_BELARUSIAN, "by" },
	{ LANG_CATALAN,    "ca" },
	{ LANG_CZECH,      "cs" },
	//{ LANG_WELSH,      "cy" },
	{ LANG_DANISH,     "da" },
	{ LANG_GERMAN,     "de" },
	{ LANG_GREEK,      "el" },
	{ LANG_ENGLISH,    "en" },
	//{ LANG_ESPERANTO,  "eo" },
	{ LANG_SPANISH,    "es" },
	{ LANG_ESTONIAN,   "et" },
	{ LANG_BASQUE,     "eu" },
	{ LANG_FARSI,      "fa" },
	{ LANG_FINNISH,    "fi" },
	{ LANG_FAEROESE,   "fo" },
	{ LANG_FRENCH,     "fr" },
	//{ LANG_GAELIC,     "ga" },
	//{ LANG_GALICIAN,   "gl" },
	{ LANG_GUJARATI,   "gu" },
	{ LANG_HEBREW,     "he" },
	{ LANG_HINDI,      "hi" },
	{ LANG_SERBIAN,    "hr" },
	{ LANG_HUNGARIAN,  "hu" },
	{ LANG_ARMENIAN,   "hy" },
	{ LANG_INDONESIAN, "id" },
	{ LANG_ITALIAN,    "it" },
	{ LANG_JAPANESE,   "ja" },
	{ LANG_GEORGIAN,   "ka" },
	{ LANG_KAZAK,      "kk" },
	{ LANG_KANNADA,    "kn" },
	{ LANG_KOREAN,     "ko" },
	//{ LANG_KYRGYZ,     "ky" },
	{ LANG_LITHUANIAN, "lt" },
	{ LANG_LATVIAN,    "lv" },
	{ LANG_MACEDONIAN, "mk" },
	//{ LANG_MONGOLIAN,  "mn" },
	{ LANG_MARATHI,    "mr" },
	{ LANG_MALAY,      "ms" },
	{ LANG_NORWEGIAN,  "nb" },
	{ LANG_DUTCH,      "nl" },
	{ LANG_NORWEGIAN,  "nn" },
	{ LANG_NORWEGIAN,  "no" },	// Unofficial ?
	{ LANG_PUNJABI,    "pa" },
	{ LANG_POLISH,     "pl" },
	{ LANG_PORTUGUESE, "pt" },
	{ LANG_ROMANIAN,   "ro" },
	{ LANG_RUSSIAN,    "ru" },
	{ LANG_SLOVAK,     "sk" },
	{ LANG_SLOVENIAN,  "sl" },
	{ LANG_ALBANIAN,   "sq" },
	{ LANG_SERBIAN,    "sr" },
	{ LANG_SWEDISH,    "sv" },
	{ LANG_SWAHILI,    "sw" },
	{ LANG_TAMIL,      "ta" },
	{ LANG_THAI,       "th" },
	{ LANG_TURKISH,    "tr" },
	{ LANG_TATAR,      "tt" },
	{ LANG_UKRAINIAN,  "uk" },
	{ LANG_URDU,       "ur" },
	{ LANG_UZBEK,      "uz" },
	{ LANG_VIETNAMESE, "vi" },
	//{ LANG_WALON,      "wa" },
	{ LANG_CHINESE,    "zh" },
};

constexpr S32 num_primary_to_code = LL_ARRAY_SIZE(primary_to_code);
constexpr S32 num_both_to_code = LL_ARRAY_SIZE(both_to_code);

static S32 lcid_to_fl(LCID lcid, FL_Locale* rtn)
{
	LANGID langid = LANGIDFROMLCID(lcid);
	LANGID primary_lang = PRIMARYLANGID(langid);
	// Try to find an exact primary/sublanguage combo that we know about
	for (S32 i = 0; i < num_both_to_code; ++i)
	{
		if (both_to_code[i].id == langid)
		{
			accumulate_locstring(both_to_code[i].code, rtn);
			return 1;
		}
	}
	// Fallback to just checking the primary language id
	for (S32 i = 0; i < num_primary_to_code; ++i)
	{
		if (primary_to_code[i].id == primary_lang)
		{
			accumulate_locstring(primary_to_code[i].code, rtn);
			return 1;
		}
	}
	return 0;
}
#endif

FL_Success FL_FindLocale(FL_Locale** locale, FL_Domain domain)
{
	FL_Success success = FL_FAILED;
	FL_Locale *rtn = (FL_Locale*)malloc(sizeof(FL_Locale));
	rtn->lang = NULL;
	rtn->country = NULL;
	rtn->variant = NULL;

#ifdef WIN32
	// win32 >= mswindows95
    LCID lcid = GetThreadLocale();
    if (lcid_to_fl(lcid, rtn))
	{
		success = FL_CONFIDENT;
	}
	else if (success == FL_FAILED)
	{
		// Assume US English on mswindows systems unless we know otherwise
		if (accumulate_locstring("en_US.ISO_8859-1", rtn))
		{
			success = FL_DEFAULT_GUESS;
		}
	}
#else	// POSIX
    // Examples: sv_SE.ISO_8859-1, fr_FR.ISO8859-1, no_NO_NB, de_DE
    // Try the various vars in decreasing order of authority
	if (accumulate_env("LC_ALL", rtn) || accumulate_env("LC_MESSAGES", rtn) ||
		accumulate_env("LANG", rtn) || accumulate_env("LANGUAGE", rtn))
	{
		success = FL_CONFIDENT;
	}
	else if (success == FL_FAILED)
	{
		// Assume US English on unixoid systems unless we know otherwise
		if (accumulate_locstring("en_US.ISO_8859-1", rtn))
		{
			success = FL_DEFAULT_GUESS;
		}
	}
#endif

	if (success != FL_FAILED)
	{
		canonise_fl(rtn);
	}

	*locale = rtn;
	return success;
}

void FL_FreeLocale(FL_Locale** locale)
{
	if (locale)
	{
		FL_Locale *l = *locale;
		if (l)
		{
			if (l->lang)
			{
				free((void*)l->lang);
			}
			if (l->country)
			{
				free((void*)l->country);
			}
			if (l->variant)
			{
				free((void*)l->variant);
			}
			free(l);
			*locale = NULL;
		}
	}
}