/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

#include <wchar.h>

#include "nlsupport.hxx"

#include <osl/mutex.h>
#include <osl/nlsupport.h>
#include <osl/diagnose.h>
#include <osl/process.h>
#include <rtl/tencinfo.h>
#include <o3tl/char16_t2wchar_t.hxx>

/* XXX NOTE:
 * http://msdn.microsoft.com/en-us/library/windows/desktop/dd373848.aspx
 * (retrieved 2013-02-13) has some weird description for the LOCALE_SISO*
 * constants: "The maximum number of characters allowed for this string is
 * nine, including a terminating null character." NINE?!? In ISO 639 and ISO
 * 3166?
 */
#define ELP_LANGUAGE_FIELD_LENGTH 4
#define ELP_COUNTRY_FIELD_LENGTH  3

namespace {

/** Struct used in EnumLocalesProcW() called via EnumSystemLocalesW() to obtain
    available locales.
*/
struct EnumLocalesParams
{
    WCHAR Language[ELP_LANGUAGE_FIELD_LENGTH];
    WCHAR Country[ELP_COUNTRY_FIELD_LENGTH];
    LCID  Locale;
};

}

static DWORD g_dwTLSLocaleEncId = DWORD(-1);

/*****************************************************************************
 * callback function test
 *****************************************************************************/

static BOOL CALLBACK EnumLocalesProcW( LPWSTR lpLocaleStringW )
{
    /* check params received via TLS */
    EnumLocalesParams * params = static_cast<EnumLocalesParams *>(TlsGetValue( g_dwTLSLocaleEncId ));
    if( nullptr == params || '\0' == params->Language[0] )
        return FALSE;

    LPWSTR pszEnd;
    WCHAR langCode[ELP_LANGUAGE_FIELD_LENGTH];

    /* convert hex-string to LCID */
    LCID localeId = wcstol(lpLocaleStringW, &pszEnd, 16);

    /*
        get the ISO language code for this locale
    */
    if( !GetLocaleInfoW( localeId, LOCALE_SISO639LANGNAME , langCode, ELP_LANGUAGE_FIELD_LENGTH ) )
        /* retry by going on */
        return TRUE;

    WCHAR ctryCode[ELP_COUNTRY_FIELD_LENGTH];

    /* continue if language code does not match */
    if( 0 != wcscmp( langCode, params->Language ) )
        return TRUE;

    /* check if country code is set and equals the current locale */
    if( '\0' != params->Country[0] && GetLocaleInfoW( localeId,
                LOCALE_SISO3166CTRYNAME , ctryCode, ELP_COUNTRY_FIELD_LENGTH ) )
    {
        /* save return value in TLS and break if found desired locale */
        if( 0 == wcscmp( ctryCode, params->Country ) )
        {
            params->Locale = localeId;
            return FALSE;
        }
    }
    else
    {
        /* fill with default values for that language */
        LANGID langId = LANGIDFROMLCID( localeId );

        /* exchange sublanguage with SUBLANG_NEUTRAL */
        langId = MAKELANGID( PRIMARYLANGID( langId ), SUBLANG_NEUTRAL );

        /* and use default sorting order */
        params->Locale = MAKELCID( langId, SORT_DEFAULT );

        return FALSE;
    }

    /* retry by going on */
    return TRUE;
}

static rtl_TextEncoding GetTextEncodingFromLCID( LCID localeId )
{
    /* query ansi codepage for given locale */
    WCHAR ansiCP[6];
    if( !localeId || !GetLocaleInfoW( localeId, LOCALE_IDEFAULTANSICODEPAGE, ansiCP, 6 ) )
        return RTL_TEXTENCODING_DONTKNOW;

    /* if GetLocaleInfo returns "0", it is a UNICODE only locale */
    if( 0 == wcscmp( ansiCP, L"0" ) )
        return RTL_TEXTENCODING_UNICODE;

    /* values returned from GetLocaleInfo are decimal based */
    WCHAR *pwcEnd;
    UINT codepage = wcstol( ansiCP, &pwcEnd, 10 );

    /* find matching rtl encoding */
    return rtl_getTextEncodingFromWindowsCodePage( codepage );
}

rtl_TextEncoding SAL_CALL osl_getTextEncodingFromLocale( rtl_Locale * pLocale )
{
    struct EnumLocalesParams params = { L"", L"", 0 };

    /* initialise global TLS id */
    if( DWORD(-1) == g_dwTLSLocaleEncId )
    {
        oslMutex globalMutex = * osl_getGlobalMutex();

        /* initializing must be thread save */
        osl_acquireMutex( globalMutex );

        if( DWORD(-1) == g_dwTLSLocaleEncId )
            g_dwTLSLocaleEncId = TlsAlloc();

        osl_releaseMutex( globalMutex );
    }

    /* if pLocale is NULL, use process locale as default */
    if( nullptr == pLocale )
        osl_getProcessLocale( &pLocale );

    /* copy in parameters to structure */
    if( !pLocale || !pLocale->Language || pLocale->Language->length >= ELP_LANGUAGE_FIELD_LENGTH )
        return RTL_TEXTENCODING_DONTKNOW;

    wcscpy( params.Language, o3tl::toW(pLocale->Language->buffer) );

    if( pLocale->Country && pLocale->Country->length < ELP_COUNTRY_FIELD_LENGTH )
        wcscpy( params.Country, o3tl::toW(pLocale->Country->buffer) );

    /* save pointer to local structure in TLS */
    TlsSetValue( g_dwTLSLocaleEncId, &params );

    /* enum all locales known to Windows */
    EnumSystemLocalesW( EnumLocalesProcW, LCID_SUPPORTED );

    /* use the LCID found in iteration */
    return GetTextEncodingFromLCID( params.Locale );
}

void imp_getProcessLocale( rtl_Locale ** ppLocale )
{
    WCHAR langCode[ELP_LANGUAGE_FIELD_LENGTH];
    WCHAR ctryCode[ELP_COUNTRY_FIELD_LENGTH];
    LCID  localeId;

    OSL_ASSERT( ppLocale );

    /* get the LCID to retrieve information from */
    localeId = GetUserDefaultLCID();

    /* call GetLocaleInfo to retrieve the iso codes */
    if( GetLocaleInfoW( localeId, LOCALE_SISO639LANGNAME , langCode, ELP_LANGUAGE_FIELD_LENGTH )  &&
        GetLocaleInfoW( localeId, LOCALE_SISO3166CTRYNAME , ctryCode, ELP_COUNTRY_FIELD_LENGTH ) )
    {
        *ppLocale = rtl_locale_register( o3tl::toU(langCode), o3tl::toU(ctryCode), u"" );
    }
    else
    {
        *ppLocale = rtl_locale_register( u"C", u"", u"" );
    }
}

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