/* -*- 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 .

 */

#include <sal/config.h>

#include <string_view>

#include <com/sun/star/container/XNameAccess.hpp>

#include <com/sun/star/i18n/DirectionProperty.hpp>

#include <com/sun/star/i18n/ScriptType.hpp>

#include <com/sun/star/uno/Sequence.hxx>

#include <com/sun/star/uno/Any.h>

#include <comphelper/lok.hxx>

#include <i18nlangtag/lang.h>

#include <i18nlangtag/mslangid.hxx>

#include <i18nlangtag/languagetag.hxx>

#include <i18nlangtag/languagetagicu.hxx>

#include <i18nutil/unicode.hxx>

#include <sal/log.hxx>

#include <vcl/svapp.hxx>

#include <vcl/settings.hxx>

#include <svtools/svtresid.hxx>

#include <svtools/langtab.hxx>

#include <unotools/syslocale.hxx>

#include <unotools/charclass.hxx>

#include <tools/resary.hxx>

#include <officecfg/VCL.hxx>

#include <langtab.hrc>

using namespace ::com::sun::star;

namespace {

class SvtLanguageTableImpl

{

private:

    std::vector<std::pair<OUString, LanguageType>> m_aStrings;

    OUString m_aUILanguage; // UI language used to build the table

    const OUString& AddItem(const OUString& rLanguage, const LanguageType eType)

    {

        return m_aStrings.emplace_back(rLanguage, eType).first;

    }

    void            Build();

public:

    SvtLanguageTableImpl();

    // In LOKit mode, rebuild the table if the UI language has changed.

    void            RebuildIfNeeded();

    bool            HasType( const LanguageType eType ) const;

    const OUString& GetString( const LanguageType eType ) const;

    LanguageType    GetType( std::u16string_view rStr ) const;

    sal_uInt32      GetEntryCount() const;

    LanguageType    GetTypeAtIndex( sal_uInt32 nIndex ) const;

    LanguageType    GetValue(sal_uInt32 nIndex) const

    {

        return (nIndex < m_aStrings.size()) ? m_aStrings[nIndex].second : LANGUAGE_DONTKNOW;

    }

    sal_uInt32      FindIndex(LanguageType nValue) const

    {

        const size_t nItems = m_aStrings.size();

        for (size_t i = 0; i < nItems; ++i)

        {

            if (m_aStrings[i].second == nValue)

                return i;

        }

        return RESARRAY_INDEX_NOTFOUND;

    }

    const OUString& AddEntry( const OUString& rString, const LanguageType eType);

};

SvtLanguageTableImpl& theLanguageTable()

{

    static SvtLanguageTableImpl aTable;

    aTable.RebuildIfNeeded();

    return aTable;

}

}

OUString ApplyLreOrRleEmbedding( const OUString &rText )

{

    const sal_Int32 nLen = rText.getLength();

    if (nLen == 0)

        return OUString();

    constexpr sal_Unicode cLRE_Embedding  = 0x202A;      // the start char of an LRE embedding

    constexpr sal_Unicode cRLE_Embedding  = 0x202B;      // the start char of an RLE embedding

    constexpr sal_Unicode cPopDirectionalFormat = 0x202C;   // the unicode PDF (POP_DIRECTIONAL_FORMAT) char that terminates an LRE/RLE embedding

    // check if there are already embedding characters at the strings start

    // if so change nothing

    const sal_Unicode cChar = rText[0];

    if (cChar == cLRE_Embedding || cChar == cRLE_Embedding)

        return rText;

    // since we only call the function getCharacterDirection

    // it does not matter which locale the CharClass is for.

    // Thus we can readily make use of SvtSysLocale::GetCharClass()

    // which should come at no cost...

    SvtSysLocale aSysLocale;

    const CharClass &rCharClass = aSysLocale.GetCharClass();

    // we should look for the first non-neutral LTR or RTL character

    // and use that to determine the embedding of the whole text...

    // Thus we can avoid to check every character of the text.

    bool bFound     = false;

    bool bIsRtlText = false;

    for (sal_Int32 i = 0;  i < nLen && !bFound;  ++i)

    {

        i18n::DirectionProperty nDirection = rCharClass.getCharacterDirection( rText, i );

        switch (nDirection)

        {

            case i18n::DirectionProperty_LEFT_TO_RIGHT :

            case i18n::DirectionProperty_LEFT_TO_RIGHT_EMBEDDING :

            case i18n::DirectionProperty_LEFT_TO_RIGHT_OVERRIDE :

            case i18n::DirectionProperty_EUROPEAN_NUMBER :

            case i18n::DirectionProperty_ARABIC_NUMBER :        // yes! arabic numbers are written from left to right

            {

                bIsRtlText  = false;

                bFound      = true;

                break;

            }

            case i18n::DirectionProperty_RIGHT_TO_LEFT :

            case i18n::DirectionProperty_RIGHT_TO_LEFT_ARABIC :

            case i18n::DirectionProperty_RIGHT_TO_LEFT_EMBEDDING :

            case i18n::DirectionProperty_RIGHT_TO_LEFT_OVERRIDE :

            {

                bIsRtlText  = true;

                bFound      = true;

                break;

            }

            default:

            {

                // nothing to be done, character is considered to be neutral we need to look further ...

            }

        }

    }

    sal_Unicode cStart  = cLRE_Embedding;   // default is to use LRE embedding characters

    if (bIsRtlText)

        cStart = cRLE_Embedding;            // then use RLE embedding

    // add embedding start and end chars to the text if the direction could be determined

    OUString aRes( rText );

    if (bFound)

    {

        aRes = OUStringChar(cStart) + aRes

            + OUStringChar(cPopDirectionalFormat);

    }

    return aRes;

}

static OUString lcl_getDescription( const LanguageTag& rTag )

{

    OUString aStr( LanguageTagIcu::getDisplayName( rTag, Application::GetSettings().GetUILanguageTag()));

    if (aStr.isEmpty() || aStr == rTag.getBcp47())

    {

        // Place in curly brackets, so all on-the-fly tags without display name

        // are grouped together at the top of a listbox (but behind the

        // "[None]" entry), and not sprinkled all over, which alphabetically

        // might make sense in an English UI only anyway. Also a visual

        // indicator that it is a programmatical name, IMHO.

        return OUString::Concat("{") + aStr + "}";

    }

    else

    {

        // The ICU display name might be identical to a predefined name or even

        // to another tag's ICU name; clarify that this is a generated name and

        // append the language tag in curly brackets to distinguish.

        return aStr + " {" + rTag.getBcp47() + "}";

    }

}

SvtLanguageTableImpl::SvtLanguageTableImpl()

{

    Build();

}

void SvtLanguageTableImpl::Build()

{

    m_aStrings.clear();

    for (const auto& [rResId, rType] : STR_ARR_SVT_LANGUAGE_TABLE)

    {

        m_aStrings.emplace_back(SvtResId(rResId), rType);

    }

    auto xNA = officecfg::VCL::ExtraLanguages::get();

    const uno::Sequence <OUString> rElementNames = xNA->getElementNames();

    for (const OUString& rBcp47 : rElementNames)

    {

        OUString aName;

        sal_Int32 nType = 0;

        uno::Reference <container::XNameAccess> xNB;

        xNA->getByName(rBcp47) >>= xNB;

        bool bSuccess = (xNB->getByName(u"Name"_ustr) >>= aName) &&

                        (xNB->getByName(u"ScriptType"_ustr) >>= nType);

        if (bSuccess)

        {

            LanguageTag aLang(rBcp47);

            LanguageType nLangType = aLang.getLanguageType();

            if (nType <= sal_Int32(LanguageTag::ScriptType::RTL) && nType > sal_Int32(LanguageTag::ScriptType::UNKNOWN))

                aLang.setScriptType(LanguageTag::ScriptType(nType));

            sal_uInt32 nPos = FindIndex(nLangType);

            if (nPos == RESARRAY_INDEX_NOTFOUND)

                AddEntry( (aName.isEmpty() ? lcl_getDescription(aLang) : aName), nLangType);

        }

    }

    m_aUILanguage = SvtSysLocale().GetUILanguageTag().getBcp47();

}

void SvtLanguageTableImpl::RebuildIfNeeded()

{

    if (!comphelper::LibreOfficeKit::isActive())

        return;

    OUString aCurrLang = SvtSysLocale().GetUILanguageTag().getBcp47();

    if (m_aUILanguage != aCurrLang)

        Build();

}

bool SvtLanguageTableImpl::HasType( const LanguageType eType ) const

{

    LanguageType eLang = MsLangId::getReplacementForObsoleteLanguage( eType );

    sal_uInt32 nPos = FindIndex(eLang);

    return RESARRAY_INDEX_NOTFOUND != nPos && nPos < GetEntryCount();

}

bool SvtLanguageTable::HasLanguageType( const LanguageType eType )

{

    return theLanguageTable().HasType( eType );

}

const OUString& SvtLanguageTableImpl::GetString( const LanguageType eType ) const

{

    const LanguageType nLang = MsLangId::getReplacementForObsoleteLanguage( eType);

    const sal_uInt32 nPos = (eType == LANGUAGE_PROCESS_OR_USER_DEFAULT ?

            FindIndex(LANGUAGE_SYSTEM) : FindIndex( nLang));

    if ( RESARRAY_INDEX_NOTFOUND != nPos && nPos < GetEntryCount() )

        return m_aStrings[nPos].first;

    // Obtain from ICU, or a geeky but usable-in-a-pinch lang-tag.

    OUString sLangTag( lcl_getDescription( LanguageTag(nLang)));

    SAL_WARN("svtools.misc", "Language: 0x"

        << std::hex << nLang

        << " with unknown name, so returning generated: "

        << sLangTag);

    // And add it to the table, so it is available in all subsequent language boxes.

    return const_cast<SvtLanguageTableImpl*>(this)->AddEntry( sLangTag, nLang);

}

const OUString& SvtLanguageTable::GetLanguageString( const LanguageType eType )

{

    return theLanguageTable().GetString( eType );

}

LanguageType SvtLanguageTableImpl::GetType( std::u16string_view rStr ) const

{

    LanguageType eType = LANGUAGE_DONTKNOW;

    sal_uInt32 nCount = GetEntryCount();

    for ( sal_uInt32 i = 0; i < nCount; ++i )

    {

        if (m_aStrings[i].first == rStr)

        {

            eType = GetValue(i);

            break;

        }

    }

    return eType;

}

LanguageType SvtLanguageTable::GetLanguageType( std::u16string_view rStr )

{

    return theLanguageTable().GetType( rStr );

}

sal_uInt32 SvtLanguageTableImpl::GetEntryCount() const

{

    return m_aStrings.size();

}

sal_uInt32 SvtLanguageTable::GetLanguageEntryCount()

{

    return theLanguageTable().GetEntryCount();

}

LanguageType SvtLanguageTableImpl::GetTypeAtIndex( sal_uInt32 nIndex ) const

{

    LanguageType nType = LANGUAGE_DONTKNOW;

    if (nIndex < GetEntryCount())

        nType = GetValue(nIndex);

    return nType;

}

LanguageType SvtLanguageTable::GetLanguageTypeAtIndex( sal_uInt32 nIndex )

{

    return theLanguageTable().GetTypeAtIndex( nIndex);

}

const OUString& SvtLanguageTableImpl::AddEntry( const OUString& rString, const LanguageType eType )

{

    if (LanguageTag::isOnTheFlyID(eType)

            && LanguageTag::getOnTheFlyScriptType(eType) == LanguageTag::ScriptType::UNKNOWN)

    {

        // Classify the script type to distribute the entry into the proper

        // language list later.

        LanguageTag aLanguageTag(eType);

        const sal_Int16 nScriptClass = unicode::getScriptClassFromLanguageTag( aLanguageTag);

        LanguageTag::ScriptType eScriptType;

        switch (nScriptClass)

        {

            default:

                eScriptType = LanguageTag::ScriptType::WESTERN;

                assert(!"unexpected ScriptType");

            break;

            case css::i18n::ScriptType::WEAK:

            case css::i18n::ScriptType::LATIN:

                eScriptType = LanguageTag::ScriptType::WESTERN;

            break;

            case css::i18n::ScriptType::ASIAN:

                eScriptType = LanguageTag::ScriptType::CJK;

            break;

            case css::i18n::ScriptType::COMPLEX:

                /* TODO: determine if it would be LanguageTag::ScriptType::RTL

                 * instead; could that be done by

                 * getScriptClassFromLanguageTag() as well by asking Unicode

                 * properties? */

                eScriptType = LanguageTag::ScriptType::CTL;

            break;

        }

        aLanguageTag.setScriptType( eScriptType);

    }

    return AddItem( rString, eType);

}

void SvtLanguageTable::AddLanguageTag( const LanguageTag& rLanguageTag )

{

    theLanguageTable().AddEntry( lcl_getDescription(rLanguageTag), rLanguageTag.getLanguageType());

}

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