/* -*- 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 "textsearch.hxx"
#include "levdis.hxx"
#include <com/sun/star/i18n/BreakIterator.hpp>
#include <com/sun/star/util/SearchAlgorithms2.hpp>
#include <com/sun/star/util/SearchFlags.hpp>
#include <com/sun/star/i18n/WordType.hpp>
#include <com/sun/star/i18n/ScriptType.hpp>
#include <com/sun/star/i18n/CharacterIteratorMode.hpp>
#include <com/sun/star/i18n/CharacterClassification.hpp>
#include <com/sun/star/i18n/KCharacterType.hpp>
#include <com/sun/star/i18n/Transliteration.hpp>
#include <cppuhelper/supportsservice.hxx>
#include <cppuhelper/weak.hxx>
#include <i18nutil/transliteration.hxx>
#include <rtl/ustrbuf.hxx>
#include <sal/log.hxx>
 
#include <unicode/regex.h>
 
using namespace ::com::sun::star::util;
using namespace ::com::sun::star::uno;
using namespace ::com::sun::star::lang;
using namespace ::com::sun::star::i18n;
using namespace ::com::sun::star;
 
const TransliterationFlags COMPLEX_TRANS_MASK =
    TransliterationFlags::ignoreBaFa_ja_JP |
    TransliterationFlags::ignoreIterationMark_ja_JP |
    TransliterationFlags::ignoreTiJi_ja_JP |
    TransliterationFlags::ignoreHyuByu_ja_JP |
    TransliterationFlags::ignoreSeZe_ja_JP |
    TransliterationFlags::ignoreIandEfollowedByYa_ja_JP |
    TransliterationFlags::ignoreKiKuFollowedBySa_ja_JP |
    TransliterationFlags::ignoreProlongedSoundMark_ja_JP;
 
namespace
{
TransliterationFlags maskComplexTrans( TransliterationFlags n )
{
    // IGNORE_KANA and FULLWIDTH_HALFWIDTH are simple but need to take effect
    // in complex transliteration.
    return
        n & (COMPLEX_TRANS_MASK |                       // all set ignore bits
        TransliterationFlags::IGNORE_KANA |            // plus IGNORE_KANA bit
        TransliterationFlags::FULLWIDTH_HALFWIDTH);    // and the FULLWIDTH_HALFWIDTH value
}
 
bool isComplexTrans( TransliterationFlags n )
{
    return bool(n & COMPLEX_TRANS_MASK);
}
 
TransliterationFlags maskSimpleTrans( TransliterationFlags n )
{
    return n & ~COMPLEX_TRANS_MASK;
}
 
bool isSimpleTrans( TransliterationFlags n )
{
    return bool(maskSimpleTrans(n));
}
 
// Regex patterns are case sensitive.
TransliterationFlags maskSimpleRegexTrans( TransliterationFlags n )
{
    TransliterationFlags m = (n & TransliterationFlags::IGNORE_MASK) & ~TransliterationFlags::IGNORE_CASE;
    TransliterationFlags v = n & TransliterationFlags::NON_IGNORE_MASK;
    if (v == TransliterationFlags::UPPERCASE_LOWERCASE || v == TransliterationFlags::LOWERCASE_UPPERCASE)
        v = TransliterationFlags::NONE;
    return (m | v) & ~COMPLEX_TRANS_MASK;
}
 
bool isSimpleRegexTrans( TransliterationFlags n )
{
    return bool(maskSimpleRegexTrans(n));
}
 
bool isReplacePunctuation( OUString &rStr )
{
    return rStr.indexOf(u'\u2018') > -1 ||
           rStr.indexOf(u'\u2019') > -1 ||
           rStr.indexOf(u'\u201A') > -1 ||
           rStr.indexOf(u'\u201B') > -1 ||
           rStr.indexOf(u'\u201C') > -1 ||
           rStr.indexOf(u'\u201D') > -1 ||
           rStr.indexOf(u'\u201E') > -1 ||
           rStr.indexOf(u'\u201F') > -1;
}
 
OUString replacePunctuation( OUString &rStr )
{
    return rStr.replace(u'\u2018', '\'')
               .replace(u'\u2019', '\'')
               .replace(u'\u201A', '\'')
               .replace(u'\u201B', '\'')
               .replace(u'\u201C', '"')
               .replace(u'\u201D', '"')
               .replace(u'\u201E', '"')
               .replace(u'\u201F', '"');
}
};
 
TextSearch::TextSearch(const Reference < XComponentContext > & rxContext)
        : m_xContext( rxContext )
{
    SearchOptions2 aOpt;
    aOpt.AlgorithmType2 = SearchAlgorithms2::ABSOLUTE;
    aOpt.algorithmType = SearchAlgorithms_ABSOLUTE;
    aOpt.searchFlag = SearchFlags::ALL_IGNORE_CASE;
    //aOpt.Locale = ???;
    setOptions( aOpt );
}
 
TextSearch::~TextSearch()
{
    pRegexMatcher.reset();
    pWLD.reset();
    pJumpTable.reset();
    pJumpTable2.reset();
}
 
void TextSearch::setOptions2( const SearchOptions2& rOptions )
{
    std::unique_lock g(m_aMutex);
 
    aSrchPara = rOptions;
 
    pRegexMatcher.reset();
    pWLD.reset();
    pJumpTable.reset();
    pJumpTable2.reset();
    maWildcardReversePattern.clear();
    maWildcardReversePattern2.clear();
    TransliterationFlags transliterateFlags = static_cast<TransliterationFlags>(aSrchPara.transliterateFlags);
    bSearchApostrophe = false;
    bool bReplaceApostrophe = false;
    if (aSrchPara.AlgorithmType2 == SearchAlgorithms2::REGEXP)
    {
        // RESrchPrepare will consider aSrchPara.transliterateFlags when
        // picking the actual regex pattern
        // (sSrchStr|sSrchStr2|SearchOptions2::searchString) and setting
        // case-insensitivity. Create transliteration instance, if any, without
        // ignore-case so later in TextSearch::searchForward() the string to
        // match is not case-altered, leave case-(in)sensitive to regex engine.
        transliterateFlags &= ~TransliterationFlags::IGNORE_CASE;
    }
    else if ( aSrchPara.searchString.indexOf('\'') > - 1 || aSrchPara.searchString.indexOf('"') > - 1 )
    {
        bSearchApostrophe = true;
        bReplaceApostrophe = isReplacePunctuation(aSrchPara.searchString);
    }
 
    // Create Transliteration class
    if( isSimpleTrans( transliterateFlags) )
    {
        if( !xTranslit.is() )
            xTranslit.set( Transliteration::create( m_xContext ) );
        xTranslit->loadModule(
             static_cast<TransliterationModules>(maskSimpleTrans(transliterateFlags)),
             aSrchPara.Locale);
    }
    else if( xTranslit.is() )
        xTranslit = nullptr;
 
    // Create Transliteration for 2<->1, 2<->2 transliteration
    if ( isComplexTrans( transliterateFlags) )
    {
        if( !xTranslit2.is() )
            xTranslit2.set( Transliteration::create( m_xContext ) );
        // Load transliteration module
        xTranslit2->loadModule(
             static_cast<TransliterationModules>(maskComplexTrans(transliterateFlags)),
             aSrchPara.Locale);
    }
 
    if ( !xBreak.is() )
        xBreak = css::i18n::BreakIterator::create( m_xContext );
 
    sSrchStr = aSrchPara.searchString;
 
    // Transliterate search string.
    if (aSrchPara.AlgorithmType2 == SearchAlgorithms2::REGEXP)
    {
        if (isSimpleRegexTrans(transliterateFlags))
        {
            if (maskSimpleRegexTrans(transliterateFlags) !=
                    maskSimpleTrans(transliterateFlags))
            {
                css::uno::Reference< XExtendedTransliteration > xTranslitPattern(
                         Transliteration::create( m_xContext ));
                if (xTranslitPattern.is())
                {
                    xTranslitPattern->loadModule(
                            static_cast<TransliterationModules>(maskSimpleRegexTrans(transliterateFlags)),
                            aSrchPara.Locale);
                    sSrchStr = xTranslitPattern->transliterateString2String(
                            aSrchPara.searchString, 0, aSrchPara.searchString.getLength());
                }
            }
            else
            {
                if (xTranslit.is())
                    sSrchStr = xTranslit->transliterateString2String(
                            aSrchPara.searchString, 0, aSrchPara.searchString.getLength());
            }
            // xTranslit2 complex transliterated sSrchStr2 is not used in
            // regex, see TextSearch::searchForward() and
            // TextSearch::searchBackward()
        }
    }
    else
    {
        if ( xTranslit.is() && isSimpleTrans(transliterateFlags) )
            sSrchStr = xTranslit->transliterateString2String(
                    aSrchPara.searchString, 0, aSrchPara.searchString.getLength());
 
        if ( xTranslit2.is() && isComplexTrans(transliterateFlags) )
            sSrchStr2 = xTranslit2->transliterateString2String(
                    aSrchPara.searchString, 0, aSrchPara.searchString.getLength());
    }
 
    if ( bReplaceApostrophe )
        sSrchStr = replacePunctuation(sSrchStr);
 
    // Take the new SearchOptions2::AlgorithmType2 field and ignore
    // SearchOptions::algorithmType
    switch( aSrchPara.AlgorithmType2)
    {
        case SearchAlgorithms2::REGEXP:
            fnForward = &TextSearch::RESrchFrwrd;
            fnBackward = &TextSearch::RESrchBkwrd;
            RESrchPrepare( aSrchPara);
            break;
 
        case SearchAlgorithms2::APPROXIMATE:
            fnForward = &TextSearch::ApproxSrchFrwrd;
            fnBackward = &TextSearch::ApproxSrchBkwrd;
 
            pWLD.reset( new WLevDistance( sSrchStr.getStr(), aSrchPara.changedChars,
                    aSrchPara.insertedChars, aSrchPara.deletedChars,
                    0 != (SearchFlags::LEV_RELAXED & aSrchPara.searchFlag ) ) );
 
            nLimit = pWLD->GetLimit();
            break;
 
        case SearchAlgorithms2::WILDCARD:
            mcWildcardEscapeChar = static_cast<sal_uInt32>(aSrchPara.WildcardEscapeCharacter);
            mbWildcardAllowSubstring = ((aSrchPara.searchFlag & SearchFlags::WILD_MATCH_SELECTION) == 0);
            fnForward = &TextSearch::WildcardSrchFrwrd;
            fnBackward = &TextSearch::WildcardSrchBkwrd;
            break;
 
        default:
            SAL_WARN("i18npool","TextSearch::setOptions2 - default what?");
            [[fallthrough]];
        case SearchAlgorithms2::ABSOLUTE:
            fnForward = &TextSearch::NSrchFrwrd;
            fnBackward = &TextSearch::NSrchBkwrd;
            break;
    }
}
 
void TextSearch::setOptions( const SearchOptions& rOptions )
{
    sal_Int16 nAlgorithmType2;
    switch (rOptions.algorithmType)
    {
        case SearchAlgorithms_REGEXP:
            nAlgorithmType2 = SearchAlgorithms2::REGEXP;
            break;
        case SearchAlgorithms_APPROXIMATE:
            nAlgorithmType2 = SearchAlgorithms2::APPROXIMATE;
            break;
        default:
            SAL_WARN("i18npool","TextSearch::setOptions - default what?");
            [[fallthrough]];
        case SearchAlgorithms_ABSOLUTE:
            nAlgorithmType2 = SearchAlgorithms2::ABSOLUTE;
            break;
    }
    // It would be nice if an inherited struct had a ctor that takes an
    // instance of the object the struct derived from...
    SearchOptions2 aOptions2(
            rOptions.algorithmType,
            rOptions.searchFlag,
            rOptions.searchString,
            rOptions.replaceString,
            rOptions.Locale,
            rOptions.changedChars,
            rOptions.deletedChars,
            rOptions.insertedChars,
            rOptions.transliterateFlags,
            nAlgorithmType2,
            0   // no wildcard search, no escape character...
            );
    setOptions2( aOptions2);
}
 
static sal_Int32 FindPosInSeq_Impl( const Sequence <sal_Int32>& rOff, sal_Int32 nPos )
{
    auto pOff = std::find_if(rOff.begin(), rOff.end(),
        [nPos](const sal_Int32 nOff) { return nOff >= nPos; });
    return static_cast<sal_Int32>(std::distance(rOff.begin(), pOff));
}
 
SearchResult TextSearch::searchForward( const OUString& searchStr, sal_Int32 startPos, sal_Int32 endPos )
{
    std::unique_lock g(m_aMutex);
 
    SearchResult sres;
 
    OUString in_str(searchStr);
 
    // in non-regex mode, allow searching typographical apostrophe with the ASCII one
    // to avoid regression after using automatic conversion to U+2019 during typing in Writer
    bool bReplaceApostrophe = bSearchApostrophe && isReplacePunctuation(in_str);
 
    bUsePrimarySrchStr = true;
 
    if ( xTranslit.is() )
    {
        // apply normal transliteration (1<->1, 1<->0)
 
        sal_Int32 nInStartPos = startPos;
        if (pRegexMatcher && startPos > 0)
        {
            // tdf#89665, tdf#75806: An optimization to avoid transliterating the whole string, yet
            // transliterate enough of the leading text to allow sensible look-behind assertions.
            // 100 is chosen arbitrarily in the hope that look-behind assertions would largely fit.
            // See http://userguide.icu-project.org/strings/regexp for look-behind assertion syntax.
            // When search regex doesn't start with an assertion, 3 is to allow startPos to be in
            // the middle of a surrogate pair, preceded by another surrogate pair.
            const sal_Int32 nMaxLeadingLen = aSrchPara.searchString.startsWith("(?") ? 100 : 3;
            nInStartPos -= std::min(nMaxLeadingLen, startPos);
        }
        sal_Int32 nInEndPos = endPos;
        if (pRegexMatcher && endPos < searchStr.getLength())
        {
            // tdf#65038: ditto for look-ahead assertions
            const sal_Int32 nMaxTrailingLen = aSrchPara.searchString.endsWith(")") ? 100 : 3;
            nInEndPos += std::min(nMaxTrailingLen, searchStr.getLength() - endPos);
        }
 
        css::uno::Sequence<sal_Int32> offset(nInEndPos - nInStartPos);
        in_str = xTranslit->transliterate(searchStr, nInStartPos, nInEndPos - nInStartPos, offset);
 
        if ( bReplaceApostrophe )
            in_str = replacePunctuation(in_str);
 
        // JP 20.6.2001: also the start and end positions must be corrected!
        sal_Int32 newStartPos =
            (startPos == 0) ? 0 : FindPosInSeq_Impl( offset, startPos );
 
        sal_Int32 newEndPos = (endPos < searchStr.getLength())
            ? FindPosInSeq_Impl( offset, endPos )
            : in_str.getLength();
 
        sres = (this->*fnForward)( g, in_str, newStartPos, newEndPos );
 
        // Map offsets back to untransliterated string.
        const sal_Int32 nOffsets = offset.getLength();
        if (nOffsets)
        {
            auto sres_startOffsetRange = asNonConstRange(sres.startOffset);
            auto sres_endOffsetRange = asNonConstRange(sres.endOffset);
            // For regex nGroups is the number of groups+1 with group 0 being
            // the entire match.
            const sal_Int32 nGroups = sres.startOffset.getLength();
            for ( sal_Int32 k = 0; k < nGroups; k++ )
            {
                const sal_Int32 nStart = sres.startOffset[k];
                // Result offsets are negative (-1) if a group expression was
                // not matched.
                if (nStart >= 0)
                    sres_startOffsetRange[k] = (nStart < nOffsets ? offset[nStart] : (offset[nOffsets - 1] + 1));
                // JP 20.6.2001: end is ever exclusive and then don't return
                //               the position of the next character - return the
                //               next position behind the last found character!
                //               "a b c" find "b" must return 2,3 and not 2,4!!!
                const sal_Int32 nStop = sres.endOffset[k];
                if (nStop >= 0)
                {
                    if (nStop > 0)
                        sres_endOffsetRange[k] = offset[(nStop <= nOffsets ? nStop : nOffsets) - 1] + 1;
                    else
                        sres_endOffsetRange[k] = offset[0];
                }
            }
        }
    }
    else
    {
        if ( bReplaceApostrophe )
            in_str = in_str.replace(u'\u2019', '\'');
 
        sres = (this->*fnForward)( g, in_str, startPos, endPos );
    }
 
    if ( xTranslit2.is() && aSrchPara.AlgorithmType2 != SearchAlgorithms2::REGEXP)
    {
        SearchResult sres2;
 
        in_str = searchStr;
        css::uno::Sequence <sal_Int32> offset( in_str.getLength());
 
        in_str = xTranslit2->transliterate( searchStr, 0, in_str.getLength(), offset );
 
        if( startPos )
            startPos = FindPosInSeq_Impl( offset, startPos );
 
        if( endPos < searchStr.getLength() )
            endPos = FindPosInSeq_Impl( offset, endPos );
        else
            endPos = in_str.getLength();
 
        bUsePrimarySrchStr = false;
        sres2 = (this->*fnForward)( g, in_str, startPos, endPos );
        auto sres2_startOffsetRange = asNonConstRange(sres2.startOffset);
        auto sres2_endOffsetRange = asNonConstRange(sres2.endOffset);
 
        for ( int k = 0; k < sres2.startOffset.getLength(); k++ )
        {
            if (sres2.startOffset[k])
                sres2_startOffsetRange[k] = offset[sres2.startOffset[k]-1] + 1;
            if (sres2.endOffset[k])
                sres2_endOffsetRange[k] = offset[sres2.endOffset[k]-1] + 1;
        }
 
        // pick first and long one
        if ( sres.subRegExpressions == 0)
            return sres2;
        if ( sres2.subRegExpressions == 1)
        {
            if ( sres.startOffset[0] > sres2.startOffset[0])
                return sres2;
            else if ( sres.startOffset[0] == sres2.startOffset[0] &&
                    sres.endOffset[0] < sres2.endOffset[0])
                return sres2;
        }
    }
 
    return sres;
}
 
SearchResult TextSearch::searchBackward( const OUString& searchStr, sal_Int32 startPos, sal_Int32 endPos )
{
    std::unique_lock g(m_aMutex);
 
    SearchResult sres;
 
    OUString in_str(searchStr);
 
    // in non-regex mode, allow searching typographical apostrophe with the ASCII one
    // to avoid regression after using automatic conversion to U+2019 during typing in Writer
    bool bReplaceApostrophe = bSearchApostrophe && isReplacePunctuation(in_str);
 
    bUsePrimarySrchStr = true;
 
    if ( xTranslit.is() )
    {
        // apply only simple 1<->1 transliteration here
        css::uno::Sequence<sal_Int32> offset(startPos - endPos);
        in_str = xTranslit->transliterate( searchStr, endPos, startPos - endPos, offset );
 
        if ( bReplaceApostrophe )
            in_str = replacePunctuation(in_str);
 
        // JP 20.6.2001: also the start and end positions must be corrected!
        sal_Int32 const newStartPos = (startPos < searchStr.getLength())
            ? FindPosInSeq_Impl( offset, startPos )
            : in_str.getLength();
 
        sal_Int32 const newEndPos =
            (endPos == 0) ? 0 : FindPosInSeq_Impl( offset, endPos );
 
        // TODO: this would need nExtraOffset handling to avoid $ matching
        // if (pRegexMatcher && startPos < searchStr.getLength())
        // but that appears to be impossible with ICU regex
 
        sres = (this->*fnBackward)( g, in_str, newStartPos, newEndPos );
 
        // Map offsets back to untransliterated string.
        const sal_Int32 nOffsets = offset.getLength();
        if (nOffsets)
        {
            auto sres_startOffsetRange = asNonConstRange(sres.startOffset);
            auto sres_endOffsetRange = asNonConstRange(sres.endOffset);
            // For regex nGroups is the number of groups+1 with group 0 being
            // the entire match.
            const sal_Int32 nGroups = sres.startOffset.getLength();
            for ( sal_Int32 k = 0; k < nGroups; k++ )
            {
                const sal_Int32 nStart = sres.startOffset[k];
                // Result offsets are negative (-1) if a group expression was
                // not matched.
                if (nStart >= 0)
                {
                    if (nStart > 0)
                        sres_startOffsetRange[k] = offset[(nStart <= nOffsets ? nStart : nOffsets) - 1] + 1;
                    else
                        sres_startOffsetRange[k] = offset[0];
                }
                // JP 20.6.2001: end is ever exclusive and then don't return
                //               the position of the next character - return the
                //               next position behind the last found character!
                //               "a b c" find "b" must return 2,3 and not 2,4!!!
                const sal_Int32 nStop = sres.endOffset[k];
                if (nStop >= 0)
                    sres_endOffsetRange[k] = (nStop < nOffsets ? offset[nStop] : (offset[nOffsets - 1] + 1));
            }
        }
    }
    else
    {
        if ( bReplaceApostrophe )
            in_str = replacePunctuation(in_str);
 
        sres = (this->*fnBackward)( g, in_str, startPos, endPos );
    }
 
    if ( xTranslit2.is() && aSrchPara.AlgorithmType2 != SearchAlgorithms2::REGEXP )
    {
        SearchResult sres2;
 
        in_str = searchStr;
        css::uno::Sequence <sal_Int32> offset( in_str.getLength());
 
        in_str = xTranslit2->transliterate(searchStr, 0, in_str.getLength(), offset);
 
        if( startPos < searchStr.getLength() )
            startPos = FindPosInSeq_Impl( offset, startPos );
        else
            startPos = in_str.getLength();
 
        if( endPos )
            endPos = FindPosInSeq_Impl( offset, endPos );
 
        bUsePrimarySrchStr = false;
        sres2 = (this->*fnBackward)( g, in_str, startPos, endPos );
        auto sres2_startOffsetRange = asNonConstRange(sres2.startOffset);
        auto sres2_endOffsetRange = asNonConstRange(sres2.endOffset);
 
        for( int k = 0; k < sres2.startOffset.getLength(); k++ )
        {
            if (sres2.startOffset[k])
                sres2_startOffsetRange[k] = offset[sres2.startOffset[k]-1]+1;
            if (sres2.endOffset[k])
                sres2_endOffsetRange[k] = offset[sres2.endOffset[k]-1]+1;
        }
 
        // pick last and long one
        if ( sres.subRegExpressions == 0 )
            return sres2;
        if ( sres2.subRegExpressions == 1 )
        {
            if ( sres.startOffset[0] < sres2.startOffset[0] )
                return sres2;
            if ( sres.startOffset[0] == sres2.startOffset[0] &&
                    sres.endOffset[0] > sres2.endOffset[0] )
                return sres2;
        }
    }
 
    return sres;
}
 
 
bool TextSearch::IsDelimiter( const OUString& rStr, sal_Int32 nPos ) const
{
    bool bRet = true;
    if( '\x7f' != rStr[nPos])
    {
        if ( !xCharClass.is() )
             xCharClass = CharacterClassification::create( m_xContext );
        sal_Int32 nCType = xCharClass->getCharacterType( rStr, nPos,
                aSrchPara.Locale );
        if( 0 != (( KCharacterType::DIGIT | KCharacterType::ALPHA |
                        KCharacterType::LETTER ) & nCType ) )
            bRet = false;
    }
    return bRet;
}
 
// --------- helper methods for Boyer-Moore like text searching ----------
// TODO: use ICU's regex UREGEX_LITERAL mode instead when it becomes available
 
void TextSearch::MakeForwardTab()
{
    // create the jumptable for the search text
 
    if( pJumpTable && bIsForwardTab )
    {
        return; // the jumpTable is ok
    }
    bIsForwardTab = true;
 
    sal_Int32 n, nLen = sSrchStr.getLength();
    pJumpTable.reset( new TextSearchJumpTable );
 
    for( n = 0; n < nLen - 1; ++n )
    {
        sal_Unicode cCh = sSrchStr[n];
        sal_Int32 nDiff = nLen - n - 1;
        TextSearchJumpTable::value_type aEntry( cCh, nDiff );
 
        ::std::pair< TextSearchJumpTable::iterator, bool > aPair =
            pJumpTable->insert( aEntry );
        if ( !aPair.second )
            (*(aPair.first)).second = nDiff;
    }
}
 
void TextSearch::MakeForwardTab2()
{
    // create the jumptable for the search text
    if( pJumpTable2 && bIsForwardTab )
    {
        return;        // the jumpTable is ok
    }
    bIsForwardTab = true;
 
    sal_Int32 n, nLen = sSrchStr2.getLength();
    pJumpTable2.reset( new TextSearchJumpTable );
 
    for( n = 0; n < nLen - 1; ++n )
    {
        sal_Unicode cCh = sSrchStr2[n];
        sal_Int32 nDiff = nLen - n - 1;
 
        TextSearchJumpTable::value_type aEntry( cCh, nDiff );
        ::std::pair< TextSearchJumpTable::iterator, bool > aPair =
            pJumpTable2->insert( aEntry );
        if ( !aPair.second )
            (*(aPair.first)).second = nDiff;
    }
}
 
void TextSearch::MakeBackwardTab()
{
    // create the jumptable for the search text
    if( pJumpTable && !bIsForwardTab)
    {
        return;   // the jumpTable is ok
    }
    bIsForwardTab = false;
 
    sal_Int32 n, nLen = sSrchStr.getLength();
    pJumpTable.reset( new TextSearchJumpTable );
 
    for( n = nLen-1; n > 0; --n )
    {
        sal_Unicode cCh = sSrchStr[n];
        TextSearchJumpTable::value_type aEntry( cCh, n );
        ::std::pair< TextSearchJumpTable::iterator, bool > aPair =
            pJumpTable->insert( aEntry );
        if ( !aPair.second )
            (*(aPair.first)).second = n;
    }
}
 
void TextSearch::MakeBackwardTab2()
{
    // create the jumptable for the search text
    if( pJumpTable2 && !bIsForwardTab )
    {
        return;    // the jumpTable is ok
    }
    bIsForwardTab = false;
 
    sal_Int32 n, nLen = sSrchStr2.getLength();
    pJumpTable2.reset( new TextSearchJumpTable );
 
    for( n = nLen-1; n > 0; --n )
    {
        sal_Unicode cCh = sSrchStr2[n];
        TextSearchJumpTable::value_type aEntry( cCh, n );
        ::std::pair< TextSearchJumpTable::iterator, bool > aPair =
            pJumpTable2->insert( aEntry );
        if ( !aPair.second )
            (*(aPair.first)).second = n;
    }
}
 
sal_Int32 TextSearch::GetDiff( const sal_Unicode cChr ) const
{
    TextSearchJumpTable *pJump;
    OUString sSearchKey;
 
    if ( bUsePrimarySrchStr ) {
        pJump = pJumpTable.get();
        sSearchKey = sSrchStr;
    } else {
        pJump = pJumpTable2.get();
        sSearchKey = sSrchStr2;
    }
 
    TextSearchJumpTable::const_iterator iLook = pJump->find( cChr );
    if ( iLook == pJump->end() )
        return sSearchKey.getLength();
    return (*iLook).second;
}
 
 
SearchResult TextSearch::NSrchFrwrd( std::unique_lock<std::mutex>& /*rGuard*/, const OUString& searchStr, sal_Int32 startPos, sal_Int32 endPos )
{
    SearchResult aRet;
    aRet.subRegExpressions = 0;
 
    OUString sSearchKey = bUsePrimarySrchStr ? sSrchStr : sSrchStr2;
 
    sal_Int32 nSuchIdx = searchStr.getLength();
    sal_Int32 nEnd = endPos;
    if( !nSuchIdx || !sSearchKey.getLength() || sSearchKey.getLength() > nSuchIdx )
        return aRet;
 
 
    if( nEnd < sSearchKey.getLength() )   // position inside the search region ?
        return aRet;
 
    nEnd -= sSearchKey.getLength();
 
    if (bUsePrimarySrchStr)
      MakeForwardTab();                   // create the jumptable
    else
      MakeForwardTab2();
 
    for (sal_Int32 nCmpIdx = startPos; // start position for the search
            nCmpIdx <= nEnd;
            nCmpIdx += GetDiff( searchStr[nCmpIdx + sSearchKey.getLength()-1]))
    {
        nSuchIdx = sSearchKey.getLength() - 1;
        while( nSuchIdx >= 0 && sSearchKey[nSuchIdx] == searchStr[nCmpIdx + nSuchIdx])
        {
            if( nSuchIdx == 0 )
            {
                if( SearchFlags::NORM_WORD_ONLY & aSrchPara.searchFlag )
                {
                    sal_Int32 nFndEnd = nCmpIdx + sSearchKey.getLength();
                    bool bAtStart = !nCmpIdx;
                    bool bAtEnd = nFndEnd == endPos;
                    bool bDelimBefore = bAtStart || IsDelimiter( searchStr, nCmpIdx-1 );
                    bool bDelimBehind = bAtEnd || IsDelimiter(  searchStr, nFndEnd );
                    //  *       1 -> only one word in the paragraph
                    //  *       2 -> at begin of paragraph
                    //  *       3 -> at end of paragraph
                    //  *       4 -> inside the paragraph
                    if( !(  ( bAtStart && bAtEnd ) ||           // 1
                                ( bAtStart && bDelimBehind ) ||     // 2
                                ( bAtEnd && bDelimBefore ) ||       // 3
                                ( bDelimBefore && bDelimBehind )))  // 4
                        break;
                }
 
                aRet.subRegExpressions = 1;
                aRet.startOffset = { nCmpIdx };
                aRet.endOffset = { nCmpIdx + sSearchKey.getLength() };
 
                return aRet;
            }
            else
                nSuchIdx--;
        }
    }
    return aRet;
}
 
SearchResult TextSearch::NSrchBkwrd( std::unique_lock<std::mutex>& /*rGuard*/,const OUString& searchStr, sal_Int32 startPos, sal_Int32 endPos )
{
    SearchResult aRet;
    aRet.subRegExpressions = 0;
 
    OUString sSearchKey = bUsePrimarySrchStr ? sSrchStr : sSrchStr2;
 
    sal_Int32 nSuchIdx = searchStr.getLength();
    sal_Int32 nEnd = endPos;
    if( nSuchIdx == 0 || sSearchKey.isEmpty() || sSearchKey.getLength() > nSuchIdx)
        return aRet;
 
    if (bUsePrimarySrchStr)
        MakeBackwardTab();                  // create the jumptable
    else
        MakeBackwardTab2();
 
    if( nEnd == nSuchIdx )                  // end position for the search
        nEnd = sSearchKey.getLength();
    else
        nEnd += sSearchKey.getLength();
 
    sal_Int32 nCmpIdx = startPos;          // start position for the search
 
    while (nCmpIdx >= nEnd)
    {
        nSuchIdx = 0;
        while( nSuchIdx < sSearchKey.getLength() && sSearchKey[nSuchIdx] ==
                searchStr[nCmpIdx + nSuchIdx - sSearchKey.getLength()] )
            nSuchIdx++;
        if( nSuchIdx >= sSearchKey.getLength() )
        {
            if( SearchFlags::NORM_WORD_ONLY & aSrchPara.searchFlag )
            {
                sal_Int32 nFndStt = nCmpIdx - sSearchKey.getLength();
                bool bAtStart = !nFndStt;
                bool bAtEnd = nCmpIdx == startPos;
                bool bDelimBehind = bAtEnd || IsDelimiter( searchStr, nCmpIdx );
                bool bDelimBefore = bAtStart || // begin of paragraph
                    IsDelimiter( searchStr, nFndStt-1 );
                //  *       1 -> only one word in the paragraph
                //  *       2 -> at begin of paragraph
                //  *       3 -> at end of paragraph
                //  *       4 -> inside the paragraph
                if( ( bAtStart && bAtEnd ) ||           // 1
                        ( bAtStart && bDelimBehind ) ||     // 2
                        ( bAtEnd && bDelimBefore ) ||       // 3
                        ( bDelimBefore && bDelimBehind ))   // 4
                {
                    aRet.subRegExpressions = 1;
                    aRet.startOffset = { nCmpIdx };
                    aRet.endOffset = { nCmpIdx - sSearchKey.getLength() };
                    return aRet;
                }
            }
            else
            {
                aRet.subRegExpressions = 1;
                aRet.startOffset = { nCmpIdx };
                aRet.endOffset = { nCmpIdx - sSearchKey.getLength() };
                return aRet;
            }
        }
        nSuchIdx = GetDiff( searchStr[nCmpIdx - sSearchKey.getLength()] );
        if( nCmpIdx < nSuchIdx )
            return aRet;
        nCmpIdx -= nSuchIdx;
    }
    return aRet;
}
 
void TextSearch::RESrchPrepare( const css::util::SearchOptions2& rOptions)
{
    TransliterationFlags transliterateFlags = static_cast<TransliterationFlags>(rOptions.transliterateFlags);
    // select the transliterated pattern string
    const OUString& rPatternStr =
        (isSimpleTrans(transliterateFlags) ? sSrchStr
        : (isComplexTrans(transliterateFlags) ? sSrchStr2 : rOptions.searchString));
 
    sal_uInt32 nIcuSearchFlags = UREGEX_UWORD; // request UAX#29 unicode capability
    // map css::util::SearchFlags to ICU uregex.h flags
    // TODO: REG_EXTENDED, REG_NOT_BEGINOFLINE, REG_NOT_ENDOFLINE
    // REG_NEWLINE is neither properly defined nor used anywhere => not implemented
    // REG_NOSUB is not used anywhere => not implemented
    // NORM_WORD_ONLY is only used for SearchAlgorithm==Absolute
    // LEV_RELAXED is only used for SearchAlgorithm==Approximate
    // Note that the search flag ALL_IGNORE_CASE is deprecated in UNO
    // probably because the transliteration flag IGNORE_CASE handles it as well.
    if( (rOptions.searchFlag & css::util::SearchFlags::ALL_IGNORE_CASE) != 0
    ||  (transliterateFlags & TransliterationFlags::IGNORE_CASE))
        nIcuSearchFlags |= UREGEX_CASE_INSENSITIVE;
    UErrorCode nIcuErr = U_ZERO_ERROR;
    // assumption: transliteration didn't mangle regexp control chars
    icu::UnicodeString aIcuSearchPatStr( reinterpret_cast<const UChar*>(rPatternStr.getStr()), rPatternStr.getLength());
#ifndef DISABLE_WORDBOUND_EMULATION
    // for convenience specific syntax elements of the old regex engine are emulated
    // - by replacing \< with "word-break followed by a look-ahead word-char"
    static const icu::UnicodeString aChevronPatternB( "\\\\<", -1, icu::UnicodeString::kInvariant);
    static const icu::UnicodeString aChevronReplaceB( "\\\\b(?=\\\\w)", -1, icu::UnicodeString::kInvariant);
    static icu::RegexMatcher aChevronMatcherB( aChevronPatternB, 0, nIcuErr);
    aChevronMatcherB.reset( aIcuSearchPatStr);
    aIcuSearchPatStr = aChevronMatcherB.replaceAll( aChevronReplaceB, nIcuErr);
    aChevronMatcherB.reset();
    // - by replacing \> with "look-behind word-char followed by a word-break"
    static const icu::UnicodeString aChevronPatternE( "\\\\>", -1, icu::UnicodeString::kInvariant);
    static const icu::UnicodeString aChevronReplaceE( "(?<=\\\\w)\\\\b", -1, icu::UnicodeString::kInvariant);
    static icu::RegexMatcher aChevronMatcherE( aChevronPatternE, 0, nIcuErr);
    aChevronMatcherE.reset( aIcuSearchPatStr);
    aIcuSearchPatStr = aChevronMatcherE.replaceAll( aChevronReplaceE, nIcuErr);
    aChevronMatcherE.reset();
#endif
    pRegexMatcher.reset( new icu::RegexMatcher( aIcuSearchPatStr, nIcuSearchFlags, nIcuErr) );
    if (nIcuErr)
    {
        SAL_INFO( "i18npool", "TextSearch::RESrchPrepare UErrorCode " << nIcuErr);
        pRegexMatcher.reset();
    }
    else
    {
        // Pathological patterns may result in exponential run time making the
        // application appear to be frozen. Limit that. Documentation for this
        // call says
        // https://unicode-org.github.io/icu-docs/apidoc/released/icu4c/classicu_1_1RegexMatcher.html#a6ebcfcab4fe6a38678c0291643a03a00
        // "The units of the limit are steps of the match engine.
        // Correspondence with actual processor time will depend on the speed
        // of the processor and the details of the specific pattern, but will
        // typically be on the order of milliseconds."
        // Just what is a good value? 42 is always an answer ... the 23 enigma
        // as well... which on the dev's machine is roughly 50 seconds with the
        // pattern of fdo#70627.
        /* TODO: make this a configuration settable value and possibly take
         * complexity of expression into account and maybe even length of text
         * to be matched; currently (2013-11-25) that is at most one 64k
         * paragraph per RESrchFrwrd()/RESrchBkwrd() call. */
        pRegexMatcher->setTimeLimit( 23*1000, nIcuErr);
    }
}
 
 
static bool lcl_findRegex(std::unique_ptr<icu::RegexMatcher> const& pRegexMatcher,
                          sal_Int32 nStartPos, sal_Int32 nEndPos, UErrorCode& rIcuErr)
{
    pRegexMatcher->region(nStartPos, nEndPos, rIcuErr);
    pRegexMatcher->useAnchoringBounds(false); // use whole text's anchoring bounds, not region's
    pRegexMatcher->useTransparentBounds(true); // take text outside of the region into account for
                                               // look-ahead/behind assertions
 
    if (!pRegexMatcher->find(rIcuErr))
    {
        /* TODO: future versions could pass the UErrorCode or translations
         * thereof to the caller, for example to inform the user of
         * U_REGEX_TIME_OUT. The strange thing though is that an error is set
         * only after the second call that returns immediately and not if
         * timeout occurred on the first call?!? */
        SAL_INFO( "i18npool", "lcl_findRegex UErrorCode " << rIcuErr);
        return false;
    }
    return true;
}
 
SearchResult TextSearch::RESrchFrwrd( std::unique_lock<std::mutex>& /*rGuard*/, const OUString& searchStr,
                                      sal_Int32 startPos, sal_Int32 endPos )
{
    SearchResult aRet;
    aRet.subRegExpressions = 0;
    if( !pRegexMatcher)
        return aRet;
 
    if( endPos > searchStr.getLength())
        endPos = searchStr.getLength();
 
    // use the ICU RegexMatcher to find the matches
    UErrorCode nIcuErr = U_ZERO_ERROR;
    const icu::UnicodeString aSearchTargetStr(false, reinterpret_cast<const UChar*>(searchStr.getStr()),
                                        searchStr.getLength());
    pRegexMatcher->reset( aSearchTargetStr);
    // search until there is a valid match
    for(;;)
    {
        if (!lcl_findRegex( pRegexMatcher, startPos, endPos, nIcuErr))
            return aRet;
 
        // #i118887# ignore zero-length matches e.g. "a*" in "bc"
        int nStartOfs = pRegexMatcher->start( nIcuErr);
        int nEndOfs = pRegexMatcher->end( nIcuErr);
        if( nStartOfs < nEndOfs)
            break;
        // If the zero-length match is behind the string, do not match it again
        // and again until startPos reaches there. A match behind the string is
        // a "$" anchor.
        if (nStartOfs == endPos)
            break;
        // try at next position if there was a zero-length match
        if( ++startPos >= endPos)
            return aRet;
    }
 
    // extract the result of the search
    const int nGroupCount = pRegexMatcher->groupCount();
    aRet.subRegExpressions = nGroupCount + 1;
    aRet.startOffset.realloc( aRet.subRegExpressions);
    auto pstartOffset = aRet.startOffset.getArray();
    aRet.endOffset.realloc( aRet.subRegExpressions);
    auto pendOffset = aRet.endOffset.getArray();
    pstartOffset[0] = pRegexMatcher->start( nIcuErr);
    pendOffset[0]   = pRegexMatcher->end( nIcuErr);
    for( int i = 1; i <= nGroupCount; ++i) {
        pstartOffset[i] = pRegexMatcher->start( i, nIcuErr);
        pendOffset[i]   = pRegexMatcher->end( i, nIcuErr);
    }
 
    return aRet;
}
 
SearchResult TextSearch::RESrchBkwrd( std::unique_lock<std::mutex>& /*rGuard*/, const OUString& searchStr,
                                      sal_Int32 startPos, sal_Int32 endPos )
{
    // NOTE: for backwards search callers provide startPos/endPos inverted!
    SearchResult aRet;
    aRet.subRegExpressions = 0;
    if( !pRegexMatcher)
        return aRet;
 
    if( startPos > searchStr.getLength())
        startPos = searchStr.getLength();
 
    // use the ICU RegexMatcher to find the matches
    // TODO: use ICU's backward searching once it becomes available
    //       as its replacement using forward search is not as good as the real thing
    UErrorCode nIcuErr = U_ZERO_ERROR;
    const icu::UnicodeString aSearchTargetStr(false, reinterpret_cast<const UChar*>(searchStr.getStr()),
                                        searchStr.getLength());
    pRegexMatcher->reset( aSearchTargetStr);
    if (!lcl_findRegex( pRegexMatcher, endPos, startPos, nIcuErr))
        return aRet;
 
    // find the last match
    int nLastPos = 0;
    int nFoundEnd = 0;
    int nGoodPos = 0, nGoodEnd = 0;
    bool bFirst = true;
    do {
        nLastPos = pRegexMatcher->start( nIcuErr);
        nFoundEnd = pRegexMatcher->end( nIcuErr);
        if (nLastPos < nFoundEnd)
        {
            // remember last non-zero-length match
            nGoodPos = nLastPos;
            nGoodEnd = nFoundEnd;
        }
        if( nFoundEnd >= startPos)
            break;
        bFirst = false;
        if( nFoundEnd == nLastPos)
            ++nFoundEnd;
    } while( lcl_findRegex( pRegexMatcher, nFoundEnd, startPos, nIcuErr));
 
    // Ignore all zero-length matches except "$" anchor on first match.
    if (nGoodPos == nGoodEnd)
    {
        if (bFirst && nLastPos == startPos)
            nGoodPos = nLastPos;
        else
            return aRet;
    }
 
    // find last match again to get its details
    lcl_findRegex( pRegexMatcher, nGoodPos, startPos, nIcuErr);
 
    // fill in the details of the last match
    const int nGroupCount = pRegexMatcher->groupCount();
    aRet.subRegExpressions = nGroupCount + 1;
    aRet.startOffset.realloc( aRet.subRegExpressions);
    auto pstartOffset = aRet.startOffset.getArray();
    aRet.endOffset.realloc( aRet.subRegExpressions);
    auto pendOffset = aRet.endOffset.getArray();
    // NOTE: existing users of backward search seem to expect startOfs/endOfs being inverted!
    pstartOffset[0] = pRegexMatcher->end( nIcuErr);
    pendOffset[0]   = pRegexMatcher->start( nIcuErr);
    for( int i = 1; i <= nGroupCount; ++i) {
        pstartOffset[i] = pRegexMatcher->end( i, nIcuErr);
        pendOffset[i]   = pRegexMatcher->start( i, nIcuErr);
    }
 
    return aRet;
}
 
 
// search for words phonetically
SearchResult TextSearch::ApproxSrchFrwrd( std::unique_lock<std::mutex>& /*rGuard*/, const OUString& searchStr,
                                          sal_Int32 startPos, sal_Int32 endPos )
{
    SearchResult aRet;
    aRet.subRegExpressions = 0;
 
    if( !xBreak.is() )
        return aRet;
 
    sal_Int32 nStt, nEnd;
 
    Boundary aWBnd = xBreak->getWordBoundary( searchStr, startPos,
            aSrchPara.Locale,
            WordType::ANYWORD_IGNOREWHITESPACES, true );
 
    do
    {
        if( aWBnd.startPos >= endPos )
            break;
        nStt = aWBnd.startPos < startPos ? startPos : aWBnd.startPos;
        nEnd = std::min(aWBnd.endPos, endPos);
 
        if( nStt < nEnd &&
                pWLD->WLD( searchStr.getStr() + nStt, nEnd - nStt ) <= nLimit )
        {
            aRet.subRegExpressions = 1;
            aRet.startOffset = { nStt };
            aRet.endOffset = { nEnd };
            break;
        }
 
        nStt = nEnd - 1;
        aWBnd = xBreak->nextWord( searchStr, nStt, aSrchPara.Locale,
                WordType::ANYWORD_IGNOREWHITESPACES);
    } while( aWBnd.startPos != aWBnd.endPos ||
            (aWBnd.endPos != searchStr.getLength() && aWBnd.endPos != nEnd) );
    // #i50244# aWBnd.endPos != nEnd : in case there is _no_ word (only
    // whitespace) in searchStr, getWordBoundary() returned startPos,startPos
    // and nextWord() does also => don't loop forever.
    return aRet;
}
 
SearchResult TextSearch::ApproxSrchBkwrd( std::unique_lock<std::mutex>& /*rGuard*/, const OUString& searchStr,
                                          sal_Int32 startPos, sal_Int32 endPos )
{
    SearchResult aRet;
    aRet.subRegExpressions = 0;
 
    if( !xBreak.is() )
        return aRet;
 
    sal_Int32 nStt, nEnd;
 
    Boundary aWBnd = xBreak->getWordBoundary( searchStr, startPos,
            aSrchPara.Locale,
            WordType::ANYWORD_IGNOREWHITESPACES, true );
 
    do
    {
        if( aWBnd.endPos <= endPos )
            break;
        nStt = aWBnd.startPos < endPos ? endPos : aWBnd.startPos;
        nEnd = std::min(aWBnd.endPos, startPos);
 
        if( nStt < nEnd &&
                pWLD->WLD( searchStr.getStr() + nStt, nEnd - nStt ) <= nLimit )
        {
            aRet.subRegExpressions = 1;
            aRet.startOffset = { nEnd };
            aRet.endOffset = { nStt };
            break;
        }
        if( !nStt )
            break;
 
        aWBnd = xBreak->previousWord( searchStr, nStt, aSrchPara.Locale,
                WordType::ANYWORD_IGNOREWHITESPACES);
    } while( aWBnd.startPos != aWBnd.endPos || aWBnd.endPos != searchStr.getLength() );
    return aRet;
}
 
 
namespace {
void setWildcardMatch( css::util::SearchResult& rRes, sal_Int32 nStartOffset, sal_Int32 nEndOffset )
{
    rRes.subRegExpressions = 1;
    rRes.startOffset = { nStartOffset };
    rRes.endOffset = { nEndOffset };
}
}
 
SearchResult TextSearch::WildcardSrchFrwrd( std::unique_lock<std::mutex>& /*rGuard*/, const OUString& searchStr, sal_Int32 nStartPos, sal_Int32 nEndPos )
{
    SearchResult aRes;
    aRes.subRegExpressions = 0;     // no match
    sal_Int32 nStartOffset = nStartPos;
    sal_Int32 nEndOffset = nEndPos;
 
    const sal_Int32 nStringLen = searchStr.getLength();
 
    // Forward nStartPos inclusive, nEndPos exclusive, but allow for empty
    // string match with [0,0).
    if (nStartPos < 0 || nEndPos > nStringLen || nEndPos < nStartPos ||
            (nStartPos == nStringLen && (nStringLen != 0 || nStartPos != nEndPos)))
        return aRes;
 
    const OUString& rPattern = (bUsePrimarySrchStr ? sSrchStr : sSrchStr2);
    const sal_Int32 nPatternLen = rPattern.getLength();
 
    // Handle special cases empty pattern and/or string outside of the loop to
    // not add performance penalties there and simplify.
    if (nStartPos == nEndPos)
    {
        sal_Int32 i = 0;
        while (i < nPatternLen && rPattern[i] == '*')
            ++i;
        if (i == nPatternLen)
            setWildcardMatch( aRes, nStartOffset, nEndOffset);
        return aRes;
    }
 
    // Empty pattern does not match any non-empty string.
    if (!nPatternLen)
        return aRes;
 
    bool bRewind = false;
    sal_uInt32 cPattern = 0;
    sal_Int32 nPattern = 0;
    sal_Int32 nAfterFakePattern = nPattern;
    if (mbWildcardAllowSubstring)
    {
        // Fake a leading '*' wildcard.
        cPattern = '*';
        bRewind = true;
        // Assume a non-'*' pattern character follows. If it is a '*' instead
        // that will be handled in the loop by setting nPat.
        sal_uInt32 cu = rPattern.iterateCodePoints( &nAfterFakePattern);
        if (cu == mcWildcardEscapeChar && mcWildcardEscapeChar && nAfterFakePattern < nPatternLen)
            rPattern.iterateCodePoints( &nAfterFakePattern);
    }
 
    sal_Int32 nString = nStartPos, nPat = -1, nStr = -1, nLastAsterisk = -1;
    sal_uInt32 cPatternAfterAsterisk = 0;
    bool bEscaped = false, bEscapedAfterAsterisk = false;
 
    // The loop code tries to avoid costly calls to iterateCodePoints() when
    // possible.
 
    do
    {
        if (bRewind)
        {
            // Reuse cPattern after '*', nPattern was correspondingly
            // incremented to point behind cPattern.
            bRewind = false;
        }
        else if (nPattern < nPatternLen)
        {
            // nPattern will be incremented by iterateCodePoints().
            cPattern = rPattern.iterateCodePoints( &nPattern);
            if (cPattern == mcWildcardEscapeChar && mcWildcardEscapeChar && nPattern < nPatternLen)
            {
                bEscaped = true;
                cPattern = rPattern.iterateCodePoints( &nPattern);
            }
        }
        else
        {
            // A trailing '*' is handled below.
            if (mbWildcardAllowSubstring)
            {
                // If the pattern is consumed and substring match allowed we're good.
                setWildcardMatch( aRes, nStartOffset, nString);
                return aRes;
            }
            else if (nString < nEndPos && nLastAsterisk >= 0)
            {
                // If substring match is not allowed try a greedy '*' match.
                nPattern = nLastAsterisk;
                continue;   // do
            }
            else
                return aRes;
        }
 
        if (cPattern == '*' && !bEscaped)
        {
            // '*' is one code unit, so not using iterateCodePoints() is ok.
            while (nPattern < nPatternLen && rPattern[nPattern] == '*')
                ++nPattern;
 
            if (nPattern >= nPatternLen)
            {
                // Last pattern is '*', remaining string matches.
                setWildcardMatch( aRes, nStartOffset, nEndOffset);
                return aRes;
            }
 
            nLastAsterisk = nPattern;   // Remember last encountered '*'.
 
            // cPattern will be the next non-'*' character, nPattern
            // incremented.
            cPattern = rPattern.iterateCodePoints( &nPattern);
            if (cPattern == mcWildcardEscapeChar && mcWildcardEscapeChar && nPattern < nPatternLen)
            {
                bEscaped = true;
                cPattern = rPattern.iterateCodePoints( &nPattern);
            }
 
            cPatternAfterAsterisk = cPattern;
            bEscapedAfterAsterisk = bEscaped;
            nPat = nPattern;    // Remember position of pattern behind '*', already incremented.
            nStr = nString;     // Remember the current string to be matched.
        }
 
        if (nString >= nEndPos)
            // Whatever follows in pattern, string will not match.
            return aRes;
 
        // nString will be incremented by iterateCodePoints().
        sal_uInt32 cString = searchStr.iterateCodePoints( &nString);
 
        if ((cPattern != '?' || bEscaped) && cPattern != cString)
        {
            if (nPat == -1)
                // Non-match already without any '*' pattern.
                return aRes;
 
            bRewind = true;
            nPattern = nPat;                    // Rewind pattern to character behind '*', already incremented.
            cPattern = cPatternAfterAsterisk;
            bEscaped = bEscapedAfterAsterisk;
            searchStr.iterateCodePoints( &nStr);
            nString = nStr;                     // Restore incremented remembered string position.
            if (nPat == nAfterFakePattern)
            {
                // Next start offset will be the next character.
                nStartOffset = nString;
            }
        }
        else
        {
            // An unescaped '?' pattern matched any character, or characters
            // matched. Reset only escaped state.
            bEscaped = false;
        }
    }
    while (nString < nEndPos);
 
    if (bRewind)
        return aRes;
 
    // Eat trailing '*' pattern that matches anything, including nothing.
    // '*' is one code unit, so not using iterateCodePoints() is ok.
    while (nPattern < nPatternLen && rPattern[nPattern] == '*')
        ++nPattern;
 
    if (nPattern == nPatternLen)
        setWildcardMatch( aRes, nStartOffset, nEndOffset);
    return aRes;
}
 
SearchResult TextSearch::WildcardSrchBkwrd( std::unique_lock<std::mutex>& /*rGuard*/, const OUString& searchStr, sal_Int32 nStartPos, sal_Int32 nEndPos )
{
    SearchResult aRes;
    aRes.subRegExpressions = 0;     // no match
 
    sal_Int32 nStartOffset = nStartPos;
    sal_Int32 nEndOffset = nEndPos;
 
    const sal_Int32 nStringLen = searchStr.getLength();
 
    // Backward nStartPos exclusive, nEndPos inclusive, but allow for empty
    // string match with (0,0].
    if (nStartPos > nStringLen || nEndPos < 0 || nStartPos < nEndPos ||
            (nEndPos == nStringLen && (nStringLen != 0 || nStartPos != nEndPos)))
        return aRes;
 
    const OUString& rPattern = (bUsePrimarySrchStr ? sSrchStr : sSrchStr2);
    sal_Int32 nPatternLen = rPattern.getLength();
 
    // Handle special cases empty pattern and/or string outside of the loop to
    // not add performance penalties there and simplify.
    if (nStartPos == nEndPos)
    {
        sal_Int32 i = 0;
        while (i < nPatternLen && rPattern[i] == '*')
            ++i;
        if (i == nPatternLen)
            setWildcardMatch( aRes, nStartOffset, nEndOffset);
        return aRes;
    }
 
    // Empty pattern does not match any non-empty string.
    if (!nPatternLen)
        return aRes;
 
    // Reverse escaped patterns to ease the handling of escapes, keeping escape
    // and following character as one sequence in backward direction.
    if ((bUsePrimarySrchStr && maWildcardReversePattern.isEmpty()) ||
            (!bUsePrimarySrchStr && maWildcardReversePattern2.isEmpty()))
    {
        OUStringBuffer aPatternBuf( rPattern);
        sal_Int32 nIndex = 0;
        while (nIndex < nPatternLen)
        {
            const sal_Int32 nOld = nIndex;
            const sal_uInt32 cu = rPattern.iterateCodePoints( &nIndex);
            if (cu == mcWildcardEscapeChar)
            {
                if (nIndex < nPatternLen)
                {
                    if (nIndex - nOld == 1)
                    {
                        // Simply move code units, we already memorized the one
                        // in 'cu'.
                        const sal_Int32 nOld2 = nIndex;
                        rPattern.iterateCodePoints( &nIndex);
                        for (sal_Int32 i=0; i < nIndex - nOld2; ++i)
                            aPatternBuf[nOld+i] = rPattern[nOld2+i];
                        aPatternBuf[nIndex-1] = static_cast<sal_Unicode>(cu);
                    }
                    else
                    {
                        // Copy the escape character code units first in the
                        // unlikely case that it would not be of BMP.
                        assert(nIndex - nOld == 2);  // it's UTF-16, so...
                        sal_Unicode buf[2];
                        buf[0] = rPattern[nOld];
                        buf[1] = rPattern[nOld+1];
                        const sal_Int32 nOld2 = nIndex;
                        rPattern.iterateCodePoints( &nIndex);
                        for (sal_Int32 i=0; i < nIndex - nOld2; ++i)
                            aPatternBuf[nOld+i] = rPattern[nOld2+i];
                        aPatternBuf[nIndex-2] = buf[0];
                        aPatternBuf[nIndex-1] = buf[1];
                    }
                }
                else
                {
                    // Trailing escape would become leading escape, do what?
                    // Eliminate.
                    aPatternBuf.remove( nOld, nIndex - nOld);
                }
            }
        }
        if (bUsePrimarySrchStr)
            maWildcardReversePattern = aPatternBuf.makeStringAndClear();
        else
            maWildcardReversePattern2 = aPatternBuf.makeStringAndClear();
    }
    const OUString& rReversePattern = (bUsePrimarySrchStr ? maWildcardReversePattern : maWildcardReversePattern2);
    nPatternLen = rReversePattern.getLength();
 
    bool bRewind = false;
    sal_uInt32 cPattern = 0;
    sal_Int32 nPattern = nPatternLen;
    sal_Int32 nAfterFakePattern = nPattern;
    if (mbWildcardAllowSubstring)
    {
        // Fake a trailing '*' wildcard.
        cPattern = '*';
        bRewind = true;
        // Assume a non-'*' pattern character follows. If it is a '*' instead
        // that will be handled in the loop by setting nPat.
        sal_uInt32 cu = rReversePattern.iterateCodePoints( &nAfterFakePattern, -1);
        if (cu == mcWildcardEscapeChar && mcWildcardEscapeChar && nAfterFakePattern > 0)
            rReversePattern.iterateCodePoints( &nAfterFakePattern, -1);
    }
 
    sal_Int32 nString = nStartPos, nPat = -1, nStr = -1, nLastAsterisk = -1;
    sal_uInt32 cPatternAfterAsterisk = 0;
    bool bEscaped = false, bEscapedAfterAsterisk = false;
 
    // The loop code tries to avoid costly calls to iterateCodePoints() when
    // possible.
 
    do
    {
        if (bRewind)
        {
            // Reuse cPattern after '*', nPattern was correspondingly
            // decremented to point before cPattern.
            bRewind = false;
        }
        else if (nPattern > 0)
        {
            // nPattern will be decremented by iterateCodePoints().
            cPattern = rReversePattern.iterateCodePoints( &nPattern, -1);
            if (cPattern == mcWildcardEscapeChar && mcWildcardEscapeChar && nPattern > 0)
            {
                bEscaped = true;
                cPattern = rReversePattern.iterateCodePoints( &nPattern, -1);
            }
        }
        else
        {
            // A trailing '*' is handled below.
            if (mbWildcardAllowSubstring)
            {
                // If the pattern is consumed and substring match allowed we're good.
                setWildcardMatch( aRes, nStartOffset, nString);
                return aRes;
            }
            else if (nString > nEndPos && nLastAsterisk >= 0)
            {
                // If substring match is not allowed try a greedy '*' match.
                nPattern = nLastAsterisk;
                continue;   // do
            }
            else
                return aRes;
        }
 
        if (cPattern == '*' && !bEscaped)
        {
            // '*' is one code unit, so not using iterateCodePoints() is ok.
            while (nPattern > 0 && rReversePattern[nPattern-1] == '*')
                --nPattern;
 
            if (nPattern <= 0)
            {
                // First pattern is '*', remaining string matches.
                setWildcardMatch( aRes, nStartOffset, nEndOffset);
                return aRes;
            }
 
            nLastAsterisk = nPattern;   // Remember last encountered '*'.
 
            // cPattern will be the previous non-'*' character, nPattern
            // decremented.
            cPattern = rReversePattern.iterateCodePoints( &nPattern, -1);
            if (cPattern == mcWildcardEscapeChar && mcWildcardEscapeChar && nPattern > 0)
            {
                bEscaped = true;
                cPattern = rReversePattern.iterateCodePoints( &nPattern, -1);
            }
 
            cPatternAfterAsterisk = cPattern;
            bEscapedAfterAsterisk = bEscaped;
            nPat = nPattern;    // Remember position of pattern before '*', already decremented.
            nStr = nString;     // Remember the current string to be matched.
        }
 
        if (nString <= nEndPos)
            // Whatever leads in pattern, string will not match.
            return aRes;
 
        // nString will be decremented by iterateCodePoints().
        sal_uInt32 cString = searchStr.iterateCodePoints( &nString, -1);
 
        if ((cPattern != '?' || bEscaped) && cPattern != cString)
        {
            if (nPat == -1)
                // Non-match already without any '*' pattern.
                return aRes;
 
            bRewind = true;
            nPattern = nPat;                    // Rewind pattern to character before '*', already decremented.
            cPattern = cPatternAfterAsterisk;
            bEscaped = bEscapedAfterAsterisk;
            searchStr.iterateCodePoints( &nStr, -1);
            nString = nStr;                     // Restore decremented remembered string position.
            if (nPat == nAfterFakePattern)
            {
                // Next start offset will be this character (exclusive).
                nStartOffset = nString;
            }
        }
        else
        {
            // An unescaped '?' pattern matched any character, or characters
            // matched. Reset only escaped state.
            bEscaped = false;
        }
    }
    while (nString > nEndPos);
 
    if (bRewind)
        return aRes;
 
    // Eat leading '*' pattern that matches anything, including nothing.
    // '*' is one code unit, so not using iterateCodePoints() is ok.
    while (nPattern > 0 && rReversePattern[nPattern-1] == '*')
        --nPattern;
 
    if (nPattern == 0)
        setWildcardMatch( aRes, nStartOffset, nEndOffset);
    return aRes;
}
 
 
OUString SAL_CALL
TextSearch::getImplementationName()
{
    return u"com.sun.star.util.TextSearch_i18n"_ustr;
}
 
sal_Bool SAL_CALL TextSearch::supportsService(const OUString& rServiceName)
{
    return cppu::supportsService(this, rServiceName);
}
 
Sequence< OUString > SAL_CALL
TextSearch::getSupportedServiceNames()
{
    return { u"com.sun.star.util.TextSearch"_ustr, u"com.sun.star.util.TextSearch2"_ustr };
}
 
extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface*
i18npool_TextSearch_get_implementation(
    css::uno::XComponentContext* context , css::uno::Sequence<css::uno::Any> const&)
{
    return cppu::acquire(new TextSearch(context));
}
 
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

V530 The return value of function 'remove' is required to be utilized.

V1053 Calling the 'setOptions' virtual function in the constructor may lead to unexpected result at runtime.

V764 Possible incorrect order of arguments passed to 'lcl_findRegex' function: 'endPos' and 'startPos'.