/* This file is (c) 2008-2012 Konstantin Isakov <ikm@goldendict.org>
 * Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */

#include "stardict.hh"
#include "btreeidx.hh"
#include "folding.hh"
#include "utf8.hh"
#include "chunkedstorage.hh"
#include "dictzip.hh"
#include "xdxf2html.hh"
#include "htmlescape.hh"
#include "langcoder.hh"
#include "gddebug.hh"
#include "fsencoding.hh"
#include "filetype.hh"
#include "indexedzip.hh"
#include "tiff.hh"
#include "ftshelpers.hh"
#include "wstring_qt.hh"
#include "audiolink.hh"

#include <zlib.h>
#include <map>
#include <set>
#include <string>
// msvc defines _WIN32 https://learn.microsoft.com/en-us/cpp/preprocessor/predefined-macros?view=msvc-170
// gcc also defines __WIN32, _WIN32, __WIN32__
// todo: unify how windows are detected on headers
#ifndef _WIN32
#include <arpa/inet.h>
#else
#include <winsock.h>
#endif
#include <stdlib.h>

#ifdef _MSC_VER
#include <stub_msvc.h>
#endif

#include <QString>
#include <QSemaphore>
#include <QThreadPool>
#include <QAtomicInt>
#if (QT_VERSION >= QT_VERSION_CHECK(6,0,0))
#include <QtCore5Compat/QRegExp>
#else
#include <QRegExp>
#endif
#include <QStringList>
#include <QDomDocument>
#include <QDomNode>
#include "ufile.hh"
#include "utils.hh"

#include <QRegularExpression>

namespace Stardict {

using std::map;
using std::multimap;
using std::pair;
using std::set;
using std::string;
using gd::wstring;

using BtreeIndexing::WordArticleLink;
using BtreeIndexing::IndexedWords;
using BtreeIndexing::IndexInfo;

namespace {

DEF_EX( exNotAnIfoFile, "Not an .ifo file", Dictionary::Ex )
DEF_EX_STR( exBadFieldInIfo, "Bad field in .ifo file encountered:", Dictionary::Ex )
DEF_EX_STR( exNoIdxFile, "No corresponding .idx file was found for", Dictionary::Ex )
DEF_EX_STR( exNoDictFile, "No corresponding .dict file was found for", Dictionary::Ex )
DEF_EX_STR( exNoSynFile, "No corresponding .syn file was found for", Dictionary::Ex )

DEF_EX( ex64BitsNotSupported, "64-bit indices are not presently supported, sorry", Dictionary::Ex )
DEF_EX( exDicttypeNotSupported, "Dictionaries with dicttypes are not supported, sorry", Dictionary::Ex )

DEF_EX_STR( exCantReadFile, "Can't read file", Dictionary::Ex )
DEF_EX_STR( exWordIsTooLarge, "Enountered a word that is too large:", Dictionary::Ex )
DEF_EX_STR( exSuddenEndOfFile, "Sudden end of file", Dictionary::Ex )
DEF_EX_STR( exDictzipError, "DICTZIP error", Dictionary::Ex )

DEF_EX_STR( exIncorrectOffset, "Incorrect offset encountered in file", Dictionary::Ex )

/// Contents of an ifo file
struct Ifo
{
  string version;
  string bookname;
  uint32_t wordcount, synwordcount, idxfilesize, idxoffsetbits;
  string sametypesequence, dicttype, description;
  string copyright, author, email, website, date;

  Ifo( File::Class & );
};

enum
{
  Signature = 0x58444953, // SIDX on little-endian, XDIS on big-endian
  CurrentFormatVersion = 9 + BtreeIndexing::FormatVersion + Folding::Version
};

struct IdxHeader
{
  uint32_t signature; // First comes the signature, SIDX
  uint32_t formatVersion; // File format version (CurrentFormatVersion)
  uint32_t chunksOffset; // The offset to chunks' storage
  uint32_t indexBtreeMaxElements; // Two fields from IndexInfo
  uint32_t indexRootOffset;
  uint32_t wordCount; // Saved from Ifo::wordcount
  uint32_t synWordCount; // Saved from Ifo::synwordcount
  uint32_t bookNameSize; // Book name's length. Used to read it then.
  uint32_t sameTypeSequenceSize; // That string's size. Used to read it then.
  uint32_t langFrom;  // Source language
  uint32_t langTo;    // Target language
  uint32_t hasZipFile; // Non-zero means there's a zip file with resources present
  uint32_t zipIndexBtreeMaxElements; // Two fields from IndexInfo of the zip
                                     // resource index.
  uint32_t zipIndexRootOffset;
}
#ifndef _MSC_VER
__attribute__((packed))
#endif
;

bool indexIsOldOrBad( string const & indexFile )
{
  File::Class idx( indexFile, "rb" );

  IdxHeader header;

  return idx.readRecords( &header, sizeof( header ), 1 ) != 1 ||
         header.signature != Signature ||
         header.formatVersion != CurrentFormatVersion;
}

class StardictDictionary: public BtreeIndexing::BtreeDictionary
{
  Mutex idxMutex;
  File::Class idx;
  IdxHeader idxHeader;
  string bookName;
  string sameTypeSequence;
  ChunkedStorage::Reader chunks;
  Mutex dzMutex;
  dictData * dz;
  Mutex resourceZipMutex;
  IndexedZip resourceZip;

public:

  StardictDictionary( string const & id, string const & indexFile,
                      vector< string > const & dictionaryFiles );

  ~StardictDictionary();

  string getName() noexcept override
  { return bookName; }

  map< Dictionary::Property, string > getProperties() noexcept override
  { return map< Dictionary::Property, string >(); }

  unsigned long getArticleCount() noexcept override
  { return idxHeader.wordCount; }

  unsigned long getWordCount() noexcept override
  { return idxHeader.wordCount + idxHeader.synWordCount; }

  inline quint32 getLangFrom() const override
  { return idxHeader.langFrom; }

  inline quint32 getLangTo() const override
  { return idxHeader.langTo; }

  sptr< Dictionary::WordSearchRequest > findHeadwordsForSynonym( wstring const & ) override
    ;

  sptr< Dictionary::DataRequest > getArticle( wstring const &,
                                                      vector< wstring > const & alts,
                                                      wstring const &,
                                                      bool ignoreDiacritics ) override
    ;

  sptr< Dictionary::DataRequest > getResource( string const & name ) override
    ;

  QString const& getDescription() override;

  QString getMainFilename() override;

  sptr< Dictionary::DataRequest > getSearchResults( QString const & searchString,
                                                            int searchMode, bool matchCase,
                                                            int distanceBetweenWords,
                                                            int maxResults,
                                                            bool ignoreWordsOrder,
                                                            bool ignoreDiacritics ) override;
  void getArticleText( uint32_t articleAddress, QString & headword, QString & text ) override;

  void makeFTSIndex(QAtomicInt & isCancelled, bool firstIteration ) override;

  void setFTSParameters( Config::FullTextSearch const & fts ) override
  {
    can_FTS = fts.enabled
              && !fts.disabledTypes.contains( "STARDICT", Qt::CaseInsensitive )
              && ( fts.maxDictionarySize == 0 || getArticleCount() <= fts.maxDictionarySize );
  }
protected:

  void loadIcon() noexcept override;

private:

  /// Retrieves the article's offset/size in .dict file, and its headword.
  void getArticleProps( uint32_t articleAddress,
                        string & headword,
                        uint32_t & offset, uint32_t & size );

  /// Loads the article, storing its headword and formatting the data it has
  /// into an html.
  void loadArticle(  uint32_t address,
                     string & headword,
                     string & articleText );

  string loadString( size_t size );

  string handleResource( char type, char const * resource, size_t size );

  void pangoToHtml( QString & text );

  friend class StardictResourceRequest;
  friend class StardictArticleRequest;
  friend class StardictHeadwordsRequest;
};

StardictDictionary::StardictDictionary( string const & id,
                                        string const & indexFile,
                                        vector< string > const & dictionaryFiles ):
  BtreeDictionary( id, dictionaryFiles ),
  idx( indexFile, "rb" ),
  idxHeader( idx.read< IdxHeader >() ),
  bookName( loadString( idxHeader.bookNameSize ) ),
  sameTypeSequence( loadString( idxHeader.sameTypeSequenceSize ) ),
  chunks( idx, idxHeader.chunksOffset )
{
  // Open the .dict file

  DZ_ERRORS error;
  dz = dict_data_open( dictionaryFiles[ 2 ].c_str(), &error, 0 );

  if ( !dz )
    throw exDictzipError( string( dz_error_str( error ) )
                          + "(" + dictionaryFiles[ 2 ] + ")" );

  // Initialize the index

  openIndex( IndexInfo( idxHeader.indexBtreeMaxElements,
                        idxHeader.indexRootOffset ),
             idx, idxMutex );

  // Open a resource zip file, if there's one

  if ( idxHeader.hasZipFile &&
       ( idxHeader.zipIndexBtreeMaxElements ||
         idxHeader.zipIndexRootOffset ) )
  {
    resourceZip.openIndex( IndexInfo( idxHeader.zipIndexBtreeMaxElements,
                                      idxHeader.zipIndexRootOffset ),
                           idx, idxMutex );

    QString zipName = QDir::fromNativeSeparators( getDictionaryFilenames().back().c_str() );

    if ( zipName.endsWith( ".zip", Qt::CaseInsensitive ) ) // Sanity check
      resourceZip.openZipFile( zipName );
  }

  // Full-text search parameters

  can_FTS = true;

  ftsIdxName = indexFile + Dictionary::getFtsSuffix();

  if( !Dictionary::needToRebuildIndex( dictionaryFiles, ftsIdxName )
      && !FtsHelpers::ftsIndexIsOldOrBad( ftsIdxName, this ) )
    FTS_index_completed.ref();
}

StardictDictionary::~StardictDictionary()
{
  if ( dz )
    dict_data_close( dz );
}

void StardictDictionary::loadIcon() noexcept
{
  if ( dictionaryIconLoaded )
    return;

  QString fileName = QDir::fromNativeSeparators( getDictionaryFilenames()[ 0 ].c_str() );

  // Remove the extension
  fileName.chop( 3 );

  if( !loadIconFromFile( fileName ) )
  {
    // Load failed -- use default icons
    dictionaryNativeIcon = dictionaryIcon = QIcon(":/icons/icon32_stardict.png");
  }

  dictionaryIconLoaded = true;
}

string StardictDictionary::loadString( size_t size )
{
  if( size == 0 )
    return string();

  vector< char > data( size );

  idx.read( &data.front(), data.size() );

  return string( &data.front(), data.size() );
}

void StardictDictionary::getArticleProps( uint32_t articleAddress,
                                          string & headword,
                                          uint32_t & offset, uint32_t & size )
{
  vector< char > chunk;

  Mutex::Lock _( idxMutex );

  char * articleData = chunks.getBlock( articleAddress, chunk );

  memcpy( &offset, articleData, sizeof( uint32_t ) );
  articleData += sizeof( uint32_t );
  memcpy( &size, articleData, sizeof( uint32_t ) );
  articleData += sizeof( uint32_t );

  headword = articleData;
}

class PowerWordDataProcessor{
    class PWSyntaxTranslate{
    public:
        PWSyntaxTranslate(const char* re, const char* replacement)
            : _re(re, QRegularExpression::UseUnicodePropertiesOption )

            , _replacement(replacement)
        {
        }
        const QRegularExpression & re() const {

            return _re;
        }
        const QString & replacement() const {
            return _replacement;
        }
    private:
        QRegularExpression _re;

        QString _replacement;
    };
public:
    PowerWordDataProcessor(const char* resource, size_t size)
        : _data(QString::fromUtf8(resource, size))
    {
    }

    string process() {
        QDomDocument doc;
        QString ss;
        ss = "<div class=\"sdct_k\">";
        if (!doc.setContent(_data)) {
            ss += _data ;
        } else {
            QStringList sl;
            walkNode(doc.firstChild(), sl);

            QStringListIterator itr(sl);
            while (itr.hasNext()) {
                QString s = itr.next();
                translatePW(s);
                ss += s;
                ss += "<br>";
            }
        }
        ss += "</div>";
        QByteArray ba = ss.toUtf8();
        return string(ba.data(), ba.size());
    }
private:
    void walkNode(const QDomNode& e, QStringList& sl) {
        if (e.isNull()) {
            return;
        }
        if (e.isText()) {
            sl.append(e.toText().data());
        } else {
            QDomNodeList l = e.childNodes();
            for (int i = 0; i < l.size(); ++i) {
                QDomNode n = l.at(i);
                if (n.isText()) {
                    sl.append(n.toText().data());
                } else {
                    walkNode(n, sl);
                }
            }
        }
    }

    void translatePW(QString& s){
        const int TRANSLATE_TBL_SIZE=5;
        static PWSyntaxTranslate t[TRANSLATE_TBL_SIZE]={
            PWSyntaxTranslate(R"(&[bB]\s*\{([^\{}&]+)\})", "<B>\\1</B>"),
            PWSyntaxTranslate(R"(&[iI]\s*\{([^\{}&]+)\})", "<I>\\1</I>"),
            PWSyntaxTranslate(R"(&[uU]\s*\{([^\{}&]+)\})", "<U>\\1</U>"),
            PWSyntaxTranslate(R"(&[lL]\s*\{([^\{}&]+)\})", R"(<SPAN style="color:#0000ff">\1</SPAN>)"),
            PWSyntaxTranslate(R"(&[2]\s*\{([^\{}&]+)\})", R"(<SPAN style="color:#0000ff">\1</SPAN>)")
        };

        QString old;
        while (s.compare(old) != 0) {
            for (int i = 0; i < TRANSLATE_TBL_SIZE; ++i) {
                PWSyntaxTranslate& a = t[i];
                s.replace(a.re(), a.replacement());
            }
            old = s;
        }
        s.replace(QRegularExpression( "&.\\s*\\{",
                                      QRegularExpression::UseUnicodePropertiesOption
                                      | QRegularExpression::DotMatchesEverythingOption),
                  "");
        s.replace("}", "");
    }
private:
    QString _data;
};


/// This function tries to make an html of the Stardict's resource typed
/// 'type', contained in a block pointed to by 'resource', 'size' bytes long.
string StardictDictionary::handleResource( char type, char const * resource, size_t size )
{
  QString text;

  // See "Type identifiers" at http://www.huzheng.org/stardict/StarDictFileFormat
  switch( type )
  {
    case 'x': // Xdxf content
      return Xdxf2Html::convert( string( resource, size ), Xdxf2Html::STARDICT, NULL, this, &resourceZip );
    case 'h': // Html content
    {
      QString articleText = QString( "<div class=\"sdct_h\">" ) + QString::fromUtf8( resource, size ) + "</div>";

      QRegularExpression imgRe( R"((<\s*img\s+[^>]*src\s*=\s*["']+)(?!(?:data|https?|ftp):))",
                                QRegularExpression::CaseInsensitiveOption
                                | QRegularExpression::InvertedGreedinessOption );
      QRegularExpression linkRe( R"((<\s*link\s+[^>]*href\s*=\s*["']+)(?!(?:data|https?|ftp):))",
                                 QRegularExpression::CaseInsensitiveOption
                                 | QRegularExpression::InvertedGreedinessOption );


      articleText.replace( imgRe , "\\1bres://" + QString::fromStdString( getId() ) + "/" )
                 .replace( linkRe, "\\1bres://" + QString::fromStdString( getId() ) + "/" );

      // Handle links to articles

      QRegularExpression linksReg( R"(<a(\s*[^>]*)href\s*=\s*['"](bword://)?([^'"]+)['"])",
                                   QRegularExpression::CaseInsensitiveOption );


      int pos = 0;
      QString articleNewText;
      QRegularExpressionMatchIterator it = linksReg.globalMatch( articleText );
      while( it.hasNext() )
      {
        QRegularExpressionMatch match = it.next();
        articleNewText += articleText.mid( pos, match.capturedStart() - pos );
        pos = match.capturedEnd();

        QString link = match.captured( 3 );

        if( link.indexOf( ':' ) < 0 )
        {
          QString newLink;
          if( link.indexOf( '#' ) < 0 )
            newLink = QString( "<a" ) + match.captured( 1 ) + "href=\"bword:" + link + "\"";


          // Anchors

          if( link.indexOf( '#' ) > 0 )
          {
            newLink = QString( "<a" ) + match.captured( 1 ) + "href=\"gdlookup://localhost/" + link + "\"";

            newLink.replace( "#", "?gdanchor=" );
          }

          if( !newLink.isEmpty() )
          {
            articleNewText += newLink;

          }
          else
            articleNewText += match.captured();

        }
        else
          articleNewText += match.captured();
      }
      if( pos )
      {
        articleNewText += articleText.mid( pos );
        articleText = articleNewText;
        articleNewText.clear();
      }


      // Handle "audio" tags

      QRegularExpression audioRe( R"(<\s*audio\s*src\s*=\s*(["']+)([^"']+)(["'])\s*>(.*)</audio>)",
                                  QRegularExpression::CaseInsensitiveOption
                                  | QRegularExpression::DotMatchesEverythingOption
                                  | QRegularExpression::InvertedGreedinessOption );


      pos = 0;

      it = audioRe.globalMatch( articleText );
      while( it.hasNext() )
      {
        QRegularExpressionMatch match = it.next();
        articleNewText += articleText.mid( pos, match.capturedStart() - pos );
        pos = match.capturedEnd();

        QString src = match.captured( 2 );

        if( src.indexOf( "://" ) >= 0 )
          articleNewText += match.captured();

        else
        {
          std::string href = "\"gdau://" + getId() + "/" + src.toUtf8().data() + "\"";
          QString newTag = QString::fromUtf8( ( addAudioLink( href, getId() ) + "<span class=\"sdict_h_wav\"><a href=" + href + ">" ).c_str() );
          newTag += match.captured( 4 );
          if( match.captured( 4 ).indexOf( "<img " ) < 0 )

            newTag += R"( <img src="qrc:///icons/playsound.png" border="0" alt="Play">)";
          newTag += "</a></span>";

          articleNewText += newTag;

        }
      }
      if( pos )
      {
        articleNewText += articleText.mid( pos );
        articleText = articleNewText;
        articleNewText.clear();
      }

      return ( articleText.toUtf8().data() );
    }
    case 'm': // Pure meaning, usually means preformatted text
      return "<div class=\"sdct_m\">" + Html::preformat( string( resource, size ), isToLanguageRTL() ) + "</div>";
    case 'l': // Same as 'm', but not in utf8, instead in current locale's
              // encoding.
              // We just use Qt here, it should know better about system's
              // locale.
      return "<div class=\"sdct_l\">" + Html::preformat( QString::fromLocal8Bit( resource, size ).toUtf8().data(),
                                                         isToLanguageRTL() )
                                      + "</div>";
    case 'g': // Pango markup.
      text = QString::fromUtf8( resource, size );
      pangoToHtml( text );
      return "<div class=\"sdct_g\">" + string( text.toUtf8().data() ) + "</div>";
    case 't': // Transcription
      return "<div class=\"sdct_t\">" + Html::escape( string( resource, size ) ) + "</div>";
    case 'y': // Chinese YinBiao or Japanese KANA. Examples are needed. For now,
              // just output as pure escaped utf8.
      return "<div class=\"sdct_y\">" + Html::escape( string( resource, size ) ) + "</div>";
    case 'k': // KingSoft PowerWord data.
    {
      PowerWordDataProcessor pwdp(resource, size);
      return pwdp.process();
    }
    case 'w': // MediaWiki markup. We don't handle this right now.
      return "<div class=\"sdct_w\">" + Html::escape( string( resource, size ) ) + "</div>";
    case 'n': // WordNet data. We don't know anything about it.
      return "<div class=\"sdct_n\">" + Html::escape( string( resource, size ) ) + "</div>";

    case 'r': // Resource file list. For now, only img: is handled.
    {
      string result = R"(<div class="sdct_r">)";

      // Handle img:example.jpg
      QString imgTemplate( R"(<img src="bres://)" + QString::fromStdString( getId() ) + R"(/%1">)" );

      for ( const auto & file : QString::fromUtf8( resource, size ).simplified().split( " " ) ) {
        if ( file.startsWith( "img:" ) ) {
          result += imgTemplate.arg( file.right( file.size() - file.indexOf( ":" ) - 1 ) ).toStdString();
        }
        else {
          result += Html::escape( file.toStdString() );
        }
      }

      return result + "</div>";
    }

    case 'W': // An embedded Wav file. Unhandled yet.
      return "<div class=\"sdct_W\">(an embedded .wav file)</div>";
    case 'P': // An embedded picture file. Unhandled yet.
      return "<div class=\"sdct_P\">(an embedded picture file)</div>";
  }

  if ( islower( type ) )
  {
    return string( "<b>Unknown textual entry type " ) + string( 1, type ) + ":</b> " + Html::escape( string( resource, size ) ) + "<br>";
  }
  else
    return string( "<b>Unknown blob entry type " ) + string( 1, type ) + "</b><br>";
}

void StardictDictionary::pangoToHtml( QString & text )
{
/*
 * Partially support for Pango Markup Language
 * Attributes "fallback", "lang", "gravity", "gravity_hint" just ignored
 */

  QRegExp spanRegex( "<span\\s*([^>]*)>", Qt::CaseInsensitive );
  QRegExp styleRegex( "(\\w+)=\"([^\"]*)\"" );

  text.replace( "\n", "<br>" );

  int pos = 0;
  do
  {
    pos = spanRegex.indexIn( text, pos );
    if( pos >= 0 )
    {
      QString styles = spanRegex.cap( 1 );
      QString newSpan( "<span style=\"" );
      int stylePos = 0;
      do
      {
        stylePos = styleRegex.indexIn( styles, stylePos );
        QString style = styleRegex.cap( 1 );
        if( stylePos >= 0 )
        {
          if( style.compare( "font_desc", Qt::CaseInsensitive ) == 0
              || style.compare( "font", Qt::CaseInsensitive ) == 0 )
          {
            // Parse font description

            QStringList list = styleRegex.cap( 2 ).split( " ", Qt::SkipEmptyParts );
            int n;
            QString sizeStr, stylesStr, familiesStr;
            for( n = list.size() - 1; n >= 0; n-- )
            {
              QString str = list.at( n );

              // font size
              if( str[ 0 ].isNumber() )
              {
                sizeStr = QString( "font-size:" ) + str + ";";
                continue;
              }

              // font style
              if( str.compare( "normal", Qt::CaseInsensitive ) == 0
                  || str.compare( "oblique", Qt::CaseInsensitive ) == 0
                  || str.compare( "italic", Qt::CaseInsensitive ) == 0 )
              {
                if( !stylesStr.contains( "font-style:" ) )
                  stylesStr += QString( "font-style:" ) + str + ";";
                continue;
              }

              // font variant
              if( str.compare( "smallcaps", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-variant:small-caps" ) ;
                continue;
              }

              // font weight
              if( str.compare( "ultralight", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-weight:100;" );
                continue;
              }
              if( str.compare( "light", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-weight:200;" );
                continue;
              }
              if( str.compare( "bold", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-weight:bold;" );
                continue;
              }
              if( str.compare( "ultrabold", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-weight:800;" );
                continue;
              }
              if( str.compare( "heavy", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-weight:900" );
                continue;
              }

              // font stretch
              if( str.compare( "ultracondensed", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-stretch:ultra-condensed;" );
                continue;
              }
              if( str.compare( "extracondensed", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-stretch:extra-condensed;" );
                continue;
              }
              if( str.compare( "semicondensed", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-stretch:semi-condensed;" );
                continue;
              }
              if( str.compare( "semiexpanded", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-stretch:semi-expanded;" );
                continue;
              }
              if( str.compare( "extraexpanded", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-stretch:extra-expanded;" );
                continue;
              }
              if( str.compare( "ultraexpanded", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-stretch:ultra-expanded;" );
                continue;
              }
              if( str.compare( "condensed", Qt::CaseInsensitive ) == 0
                  || str.compare( "expanded", Qt::CaseInsensitive ) == 0 )
              {
                stylesStr += QString( "font-stretch:" ) + str + ";";
                continue;
              }

              // gravity
              if( str.compare( "south", Qt::CaseInsensitive ) == 0
                  || str.compare( "east", Qt::CaseInsensitive ) == 0
                  || str.compare( "north", Qt::CaseInsensitive ) == 0
                  || str.compare( "west", Qt::CaseInsensitive ) == 0
                  || str.compare( "auto", Qt::CaseInsensitive ) == 0 )
              {
                continue;
              }
              break;
            }

            // last words is families list
            if( n >= 0 )
            {
              familiesStr = QString( "font-family:" );
              for( int i = 0; i <= n; i++ )
              {
                if( i > 0 && !familiesStr.endsWith( ',' ) )
                  familiesStr += ",";
                familiesStr += list.at( i );
              }
              familiesStr += ";";
            }

            newSpan += familiesStr + stylesStr + sizeStr;
          }
          else if( style.compare( "font_family", Qt::CaseInsensitive ) == 0
                   || style.compare( "face", Qt::CaseInsensitive ) == 0 )
            newSpan += QString( "font-family:" ) + styleRegex.cap( 2 ) + ";";
          else if( style.compare( "font_size", Qt::CaseInsensitive ) == 0
                   || style.compare( "size", Qt::CaseInsensitive ) == 0 )
          {
            if( styleRegex.cap( 2 )[ 0 ].isLetter()
                || styleRegex.cap( 2 ).endsWith( "px", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "pt", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "em", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "%" ) )
              newSpan += QString( "font-size:" ) + styleRegex.cap( 2 ) +";";
            else
            {
              int size = styleRegex.cap( 2 ).toInt();
              if( size )
                newSpan += QString( "font-size:%1pt;" ).arg( size / 1024.0, 0, 'f', 3 );
            }
          }
          else if( style.compare( "font_style", Qt::CaseInsensitive ) == 0
                   || style.compare( "style", Qt::CaseInsensitive ) == 0)
            newSpan += QString( "font-style:" ) + styleRegex.cap( 2 ) + ";";
          else if( style.compare( "weight", Qt::CaseInsensitive ) == 0
                   || style.compare( "weight", Qt::CaseInsensitive ) == 0)
          {
            QString str = styleRegex.cap( 2 );
            if( str.compare( "ultralight", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-weight:100;" );
            else if( str.compare( "light", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-weight:200;" );
            else if( str.compare( "ultrabold", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-weight:800;" );
            else if( str.compare( "heavy", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-weight:900" );
            else
              newSpan += QString( "font-weight:" ) + str + ";";
          }
          else if( style.compare( "font_variant", Qt::CaseInsensitive ) == 0
                   || style.compare( "variant", Qt::CaseInsensitive ) == 0 )
          {
            if( styleRegex.cap( 2 ).compare( "smallcaps", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-variant:small-caps" );
            else
              newSpan += QString( "font-variant:" ) + styleRegex.cap( 2 ) + ";";
          }
          else if( style.compare( "font_stretch", Qt::CaseInsensitive ) == 0
                   || style.compare( "stretch", Qt::CaseInsensitive ) == 0 )
          {
            QString str = styleRegex.cap( 2 );
            if( str.compare( "ultracondensed", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-stretch:ultra-condensed;" );
            else if( str.compare( "extracondensed", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-stretch:extra-condensed;" );
            else if( str.compare( "semicondensed", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-stretch:semi-condensed;" );
            else if( str.compare( "semiexpanded", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-stretch:semi-expanded;" );
            else if( str.compare( "extraexpanded", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-stretch:extra-expanded;" );
            else if( str.compare( "ultraexpanded", Qt::CaseInsensitive ) == 0 )
              newSpan += QString( "font-stretch:ultra-expanded;" );
            else
              newSpan += QString( "font-stretch:" ) + str + ";";
          }
          else if( style.compare( "foreground", Qt::CaseInsensitive ) == 0
                   || style.compare( "fgcolor", Qt::CaseInsensitive ) == 0
                   || style.compare( "color", Qt::CaseInsensitive ) == 0 )
            newSpan += QString( "color:" ) + styleRegex.cap( 2 ) + ";";
          else if( style.compare( "background", Qt::CaseInsensitive ) == 0
                   || style.compare( "bgcolor", Qt::CaseInsensitive ) == 0 )
            newSpan += QString( "background-color:" ) + styleRegex.cap( 2 ) + ";";
          else if( style.compare( "underline_color", Qt::CaseInsensitive ) == 0
                   || style.compare( "strikethrough_color", Qt::CaseInsensitive ) == 0 )
            newSpan += QString( "text-decoration-color:" ) + styleRegex.cap( 2 ) + ";";
          else if( style.compare( "underline", Qt::CaseInsensitive ) == 0 )
          {
            if( styleRegex.cap( 2 ).compare( "none", Qt::CaseInsensitive ) )
              newSpan += QString( "text-decoration-line:none;" );
            else
            {
              newSpan += QString( "text-decoration-line:underline; " );
              if( styleRegex.cap( 2 ).compare( "low", Qt::CaseInsensitive ) )
                newSpan += QString( "text-decoration-style:dotted;" );
              else if( styleRegex.cap( 2 ).compare( "single", Qt::CaseInsensitive ) )
                newSpan += QString( "text-decoration-style:solid;" );
              else if( styleRegex.cap( 2 ).compare( "error", Qt::CaseInsensitive ) )
                newSpan += QString( "text-decoration-style:wavy;" );
              else
                newSpan += QString( "text-decoration-style:" ) + styleRegex.cap( 2 ) + ";";
            }
          }
          else if( style.compare( "strikethrough", Qt::CaseInsensitive ) == 0 )
          {
            if( styleRegex.cap( 2 ).compare( "true", Qt::CaseInsensitive ) )
              newSpan += QString( "text-decoration-line:line-through;" );
            else
              newSpan += QString( "text-decoration-line:none;" );
          }
          else if( style.compare( "rise", Qt::CaseInsensitive ) == 0 )
          {
            if( styleRegex.cap( 2 ).endsWith( "px", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "pt", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "em", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "%" ) )
              newSpan += QString( "vertical-align:" ) + styleRegex.cap( 2 ) +";";
            else
            {
              int riseValue = styleRegex.cap( 2 ).toInt();
              if( riseValue )
                newSpan += QString( "vertical-align:%1pt;" ).arg( riseValue / 1024.0, 0, 'f', 3 );
            }
          }
          else if( style.compare( "letter_spacing", Qt::CaseInsensitive ) == 0 )
          {
            if( styleRegex.cap( 2 ).endsWith( "px", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "pt", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "em", Qt::CaseInsensitive )
                || styleRegex.cap( 2 ).endsWith( "%" ) )
              newSpan += QString( "letter-spacing:" ) + styleRegex.cap( 2 ) +";";
            else
            {
              int spacing = styleRegex.cap( 2 ).toInt();
              if( spacing )
                newSpan += QString( "letter-spacing:%1pt;" ).arg( spacing / 1024.0, 0, 'f', 3 );
            }
          }

          stylePos += styleRegex.matchedLength();
        }
      }
      while( stylePos >= 0 );

      newSpan += "\">";
      text.replace( pos, spanRegex.matchedLength(), newSpan );
      pos += newSpan.size();
    }
  }
  while( pos >= 0 );

  text.replace( "  ", "&nbsp;&nbsp;" );
}

void StardictDictionary::loadArticle( uint32_t address,
                                      string & headword,
                                      string & articleText )
{
  uint32_t offset, size;

  getArticleProps( address, headword, offset, size );

  char * articleBody;

  {
    Mutex::Lock _( dzMutex );

    // Note that the function always zero-pads the result.
    articleBody = dict_data_read_( dz, offset, size, 0, 0 );
  }

  if ( !articleBody )
  {
//    throw exCantReadFile( getDictionaryFilenames()[ 2 ] );
    articleText = string( "<div class=\"sdict_m\">DICTZIP error: " ) + dict_error_str( dz ) + "</div>";
    return;
  }

  articleText.clear();

  char * ptr = articleBody;

  if ( sameTypeSequence.size() )
  {
    /// The sequence is known, it's not stored in the article itself
    for( unsigned seq = 0; seq < sameTypeSequence.size(); ++seq )
    {
      // Last entry doesn't have size info -- it is inferred from
      // the bytes left
      bool entrySizeKnown = ( seq == sameTypeSequence.size() - 1 );

      uint32_t entrySize = 0;

      if ( entrySizeKnown )
        entrySize = size;
      else
      if ( !size )
      {
        gdWarning( "Stardict: short entry for the word %s encountered in \"%s\".\n", headword.c_str(), getName().c_str() );
        break;
      }

      char type = sameTypeSequence[ seq ];

      if ( islower( type ) )
      {
        // Zero-terminated entry, unless it's the last one
        if ( !entrySizeKnown )
          entrySize = strlen( ptr );

        if ( size < entrySize )
        {
          gdWarning( "Stardict: malformed entry for the word %s encountered in \"%s\".\n", headword.c_str(), getName().c_str() );
          break;
        }

        articleText += handleResource( type, ptr, entrySize );

        if ( !entrySizeKnown )
          ++entrySize; // Need to skip the zero byte

        ptr += entrySize;
        size -= entrySize;
      }
      else
      if ( isupper( *ptr ) )
      {
        // An entry which has its size before contents, unless it's the last one

        if ( !entrySizeKnown )
        {
          if ( size < sizeof( uint32_t ) )
          {
            gdWarning( "Stardict: malformed entry for the word %s encountered in \"%s\".\n", headword.c_str(), getName().c_str() );
            break;
          }

          memcpy( &entrySize, ptr, sizeof( uint32_t ) );

          entrySize = ntohl( entrySize );

          ptr += sizeof( uint32_t );
          size -= sizeof( uint32_t );
        }

        if ( size < entrySize )
        {
          gdWarning( "Stardict: malformed entry for the word %s encountered in \"%s\".\n", headword.c_str(), getName().c_str() );
          break;
        }

        articleText += handleResource( type, ptr, entrySize );

        ptr += entrySize;
        size -= entrySize;
      }
      else
      {
        gdWarning( "Stardict: non-alpha entry type 0x%x for the word %s encountered in \"%s\".\n",
                   type, headword.c_str(), getName().c_str() );
        break;
      }
    }
  }
  else
  {
    // The sequence is stored in each article separately
    while( size )
    {
      if ( islower( *ptr ) )
      {
        // Zero-terminated entry
        size_t len = strlen( ptr + 1 );

        if ( size < len + 2 )
        {
          gdWarning( "Stardict: malformed entry for the word %s encountered in \"%s\".\n", headword.c_str(), getName().c_str() );
          break;
        }

        articleText += handleResource( *ptr, ptr + 1, len );

        ptr += len + 2;
        size -= len + 2;
      }
      else
      if ( isupper( *ptr ) )
      {
        // An entry which havs its size before contents
        if ( size < sizeof( uint32_t ) + 1 )
        {
          gdWarning( "Stardict: malformed entry for the word %s encountered in \"%s\".\n", headword.c_str(), getName().c_str() );
          break;
        }

        uint32_t entrySize;

        memcpy( &entrySize, ptr + 1, sizeof( uint32_t ) );

        entrySize = ntohl( entrySize );

        if ( size < sizeof( uint32_t ) + 1 + entrySize )
        {
          gdWarning( "Stardict: malformed entry for the word %s encountered in \"%s\".\n", headword.c_str(), getName().c_str() );
          break;
        }

        articleText += handleResource( *ptr, ptr + 1 + sizeof( uint32_t ), entrySize );

        ptr += sizeof( uint32_t ) + 1 + entrySize;
        size -= sizeof( uint32_t ) + 1 + entrySize;
      }
      else
      {
        gdWarning( "Stardict: non-alpha entry type 0x%x for the word %s encountered in \"%s\".\n",
                   (unsigned)*ptr, headword.c_str(), getName().c_str() );
        break;
      }
    }
  }

  free( articleBody );
}

QString const& StardictDictionary::getDescription()
{
    if( !dictionaryDescription.isEmpty() )
        return dictionaryDescription;

    File::Class ifoFile( getDictionaryFilenames()[ 0 ], "r" );
    Ifo ifo( ifoFile );

    if( !ifo.copyright.empty() )
    {
      QString copyright = QString::fromUtf8( ifo.copyright.c_str() )
                          .replace( "<br>", "\n", Qt::CaseInsensitive );
      dictionaryDescription += QString( QObject::tr( "Copyright: %1%2" ) )
                              .arg( copyright )
                              .arg( "\n\n" );
    }

    if( !ifo.author.empty() )
    {
      QString author = QString::fromUtf8( ifo.author.c_str() );
      dictionaryDescription += QString( QObject::tr( "Author: %1%2" ) )
                              .arg( author )
                              .arg( "\n\n" );
    }

    if( !ifo.email.empty() )
    {
      QString email = QString::fromUtf8( ifo.email.c_str() );
      dictionaryDescription += QString( QObject::tr( "E-mail: %1%2" ) )
                               .arg( email )
                               .arg( "\n\n" );
    }

    if( !ifo.website.empty() )
    {
      QString website = QString::fromUtf8( ifo.website.c_str() );
      dictionaryDescription += QString( QObject::tr( "Website: %1%2" ) )
                               .arg( website )
                               .arg( "\n\n" );
    }

    if( !ifo.date.empty() )
    {
      QString date = QString::fromUtf8( ifo.date.c_str() );
      dictionaryDescription += QString( QObject::tr( "Date: %1%2" ) )
                               .arg( date )
                               .arg( "\n\n" );
    }

    if( !ifo.description.empty() )
    {
      QString desc = QString::fromUtf8( ifo.description.c_str() );
      desc.replace( "\t", "<br/>" );
      desc.replace( "\\n", "<br/>" );
      desc.replace( "<br>", "<br/>", Qt::CaseInsensitive );
      dictionaryDescription += Html::unescape( desc, true );
    }

    if( dictionaryDescription.isEmpty() )
      dictionaryDescription = "NONE";

    return dictionaryDescription;
}

QString StardictDictionary::getMainFilename() { return getDictionaryFilenames()[ 0 ].c_str(); }

void StardictDictionary::makeFTSIndex( QAtomicInt & isCancelled, bool firstIteration )
{
  if( !( Dictionary::needToRebuildIndex( getDictionaryFilenames(), ftsIdxName )
         || FtsHelpers::ftsIndexIsOldOrBad( ftsIdxName, this ) ) )
    FTS_index_completed.ref();

  if( haveFTSIndex() )
    return;

  if( ensureInitDone().size() )
    return;

  if( firstIteration && getArticleCount() > FTS::MaxDictionarySizeForFastSearch )
    return;

  gdDebug( "Stardict: Building the full-text index for dictionary: %s\n",
           getName().c_str() );

  try
  {
    FtsHelpers::makeFTSIndex( this, isCancelled );
    FTS_index_completed.ref();
  }
  catch( std::exception &ex )
  {
    gdWarning( "Stardict: Failed building full-text search index for \"%s\", reason: %s\n", getName().c_str(), ex.what() );
    QFile::remove( ftsIdxName.c_str() );
  }
}

void StardictDictionary::getArticleText( uint32_t articleAddress, QString & headword, QString & text )
{
  try
  {
    string headwordStr, articleStr;
    loadArticle( articleAddress, headwordStr, articleStr );

    headword = QString::fromUtf8( headwordStr.data(), headwordStr.size() );

    text = Html::unescape( QString::fromStdString( articleStr ) );
  }
  catch( std::exception &ex )
  {
    gdWarning( "Stardict: Failed retrieving article from \"%s\", reason: %s\n", getName().c_str(), ex.what() );
  }
}

sptr< Dictionary::DataRequest > StardictDictionary::getSearchResults( QString const & searchString,
                                                                      int searchMode, bool matchCase,
                                                                      int distanceBetweenWords,
                                                                      int maxResults,
                                                                      bool ignoreWordsOrder,
                                                                      bool ignoreDiacritics )
{
  return std::make_shared<FtsHelpers::FTSResultsRequest>( *this, searchString,searchMode, matchCase, distanceBetweenWords, maxResults, ignoreWordsOrder, ignoreDiacritics );
}

/// StardictDictionary::findHeadwordsForSynonym()

class StardictHeadwordsRequest;

class StardictHeadwordsRequestRunnable: public QRunnable
{
  StardictHeadwordsRequest & r;
  QSemaphore & hasExited;

public:

  StardictHeadwordsRequestRunnable( StardictHeadwordsRequest & r_,
                                    QSemaphore & hasExited_ ): r( r_ ),
                                                               hasExited( hasExited_ )
  {}

  ~StardictHeadwordsRequestRunnable()
  {
    hasExited.release();
  }

  void run() override;
};

class StardictHeadwordsRequest: public Dictionary::WordSearchRequest
{
  friend class StardictHeadwordsRequestRunnable;

  wstring word;
  StardictDictionary & dict;

  QAtomicInt isCancelled;
  QSemaphore hasExited;

public:

  StardictHeadwordsRequest( wstring const & word_,
                            StardictDictionary & dict_ ):
    word( word_ ), dict( dict_ )
  {
    QThreadPool::globalInstance()->start(
      new StardictHeadwordsRequestRunnable( *this, hasExited ) );
  }

  void run(); // Run from another thread by StardictHeadwordsRequestRunnable

  void cancel() override
  {
    isCancelled.ref();
  }

  ~StardictHeadwordsRequest()
  {
    isCancelled.ref();
    hasExited.acquire();
  }
};

void StardictHeadwordsRequestRunnable::run()
{
  r.run();
}

void StardictHeadwordsRequest::run()
{
  if ( Utils::AtomicInt::loadAcquire( isCancelled ) )
  {
    finish();
    return;
  }

  try
  {
    vector< WordArticleLink > chain = dict.findArticles( word );

    wstring caseFolded = Folding::applySimpleCaseOnly( word );

    for( unsigned x = 0; x < chain.size(); ++x )
    {
      if ( Utils::AtomicInt::loadAcquire( isCancelled ) )
      {
        finish();
        return;
      }

      string headword, articleText;

      dict.loadArticle( chain[ x ].articleOffset,
                        headword, articleText );

      wstring headwordDecoded = Utf8::decode( headword );

      if ( caseFolded != Folding::applySimpleCaseOnly( headwordDecoded ) )
      {
        // The headword seems to differ from the input word, which makes the
        // input word its synonym.
        Mutex::Lock _( dataMutex );

        matches.push_back( headwordDecoded );
      }
    }
  }
  catch( std::exception & e )
  {
    setErrorString( QString::fromUtf8( e.what() ) );
  }

  finish();
}

sptr< Dictionary::WordSearchRequest >
  StardictDictionary::findHeadwordsForSynonym( wstring const & word )
  
{
  return synonymSearchEnabled ? std::make_shared<StardictHeadwordsRequest>( word, *this ) :
                                Class::findHeadwordsForSynonym( word );
}


/// StardictDictionary::getArticle()

class StardictArticleRequest;

class StardictArticleRequestRunnable: public QRunnable
{
  StardictArticleRequest & r;
  QSemaphore & hasExited;

public:

  StardictArticleRequestRunnable( StardictArticleRequest & r_,
                                  QSemaphore & hasExited_ ): r( r_ ),
                                                             hasExited( hasExited_ )
  {}

  ~StardictArticleRequestRunnable()
  {
    hasExited.release();
  }

  void run() override;
};

class StardictArticleRequest: public Dictionary::DataRequest
{
  friend class StardictArticleRequestRunnable;

  wstring word;
  vector< wstring > alts;
  StardictDictionary & dict;
  bool ignoreDiacritics;

  QAtomicInt isCancelled;
  QSemaphore hasExited;

public:

  StardictArticleRequest( wstring const & word_,
                     vector< wstring > const & alts_,
                     StardictDictionary & dict_,
                     bool ignoreDiacritics_ ):
    word( word_ ), alts( alts_ ), dict( dict_ ), ignoreDiacritics( ignoreDiacritics_ )
  {
    QThreadPool::globalInstance()->start(
      new StardictArticleRequestRunnable( *this, hasExited ) );
  }

  void run(); // Run from another thread by StardictArticleRequestRunnable

  void cancel() override
  {
    isCancelled.ref();
  }

  ~StardictArticleRequest()
  {
    isCancelled.ref();
    hasExited.acquire();
  }
};

void StardictArticleRequestRunnable::run()
{
  r.run();
}

void StardictArticleRequest::run()
{
  if ( Utils::AtomicInt::loadAcquire( isCancelled ) )
  {
    finish();
    return;
  }

  try
  {
    vector< WordArticleLink > chain = dict.findArticles( word, ignoreDiacritics );

    for( unsigned x = 0; x < alts.size(); ++x )
    {
      /// Make an additional query for each alt

      vector< WordArticleLink > altChain = dict.findArticles( alts[ x ], ignoreDiacritics );

      chain.insert( chain.end(), altChain.begin(), altChain.end() );
    }

    multimap< wstring, pair< string, string > > mainArticles, alternateArticles;

    set< uint32_t > articlesIncluded; // Some synonims make it that the articles
                                      // appear several times. We combat this
                                      // by only allowing them to appear once.

    wstring wordCaseFolded = Folding::applySimpleCaseOnly( word );
    if( ignoreDiacritics )
      wordCaseFolded = Folding::applyDiacriticsOnly( wordCaseFolded );

    for( unsigned x = 0; x < chain.size(); ++x )
    {
      if ( Utils::AtomicInt::loadAcquire( isCancelled ) )
      {
        finish();
        return;
      }

      if ( articlesIncluded.find( chain[ x ].articleOffset ) != articlesIncluded.end() )
        continue; // We already have this article in the body.

      // Now grab that article

      string headword, articleText;

      dict.loadArticle( chain[ x ].articleOffset, headword, articleText );

      // Ok. Now, does it go to main articles, or to alternate ones? We list
      // main ones first, and alternates after.

      // We do the case-folded comparison here.

      wstring headwordStripped =
        Folding::applySimpleCaseOnly( Utf8::decode( headword ) );
      if( ignoreDiacritics )
        headwordStripped = Folding::applyDiacriticsOnly( headwordStripped );

      multimap< wstring, pair< string, string > > & mapToUse =
        ( wordCaseFolded == headwordStripped ) ?
          mainArticles : alternateArticles;

      mapToUse.insert( pair< wstring, pair< string, string > >(
        Folding::applySimpleCaseOnly( Utf8::decode( headword ) ),
        pair< string, string >( headword, articleText ) ) );

      articlesIncluded.insert( chain[ x ].articleOffset );
    }

    if ( mainArticles.empty() && alternateArticles.empty() )
    {
      // No such word
      finish();
      return;
    }

    string result;

    multimap< wstring, pair< string, string > >::const_iterator i;

    string cleaner = Utils::Html::getHtmlCleaner();

    for( i = mainArticles.begin(); i != mainArticles.end(); ++i )
    {
        result += dict.isFromLanguageRTL() ? R"(<h3 class="sdct_headwords" dir="rtl">)" : "<h3 class=\"sdct_headwords\">";
        result += i->second.first;
        result += "</h3>";
        if( dict.isToLanguageRTL() )
          result += R"(<div style="display:inline;" dir="rtl">)";
        result += i->second.second;
        result += cleaner;
        if( dict.isToLanguageRTL() )
          result += "</div>";
    }

    for( i = alternateArticles.begin(); i != alternateArticles.end(); ++i )
    {
        result += dict.isFromLanguageRTL() ? R"(<h3 class="sdct_headwords" dir="rtl">)" : "<h3 class=\"sdct_headwords\">";
        result += i->second.first;
        result += "</h3>";
        if( dict.isToLanguageRTL() )
          result += R"(<div style="display:inline;" dir="rtl">)";
        result += i->second.second;
        result += cleaner;
        if( dict.isToLanguageRTL() )
          result += "</div>";
    }

    Mutex::Lock _( dataMutex );

    data.resize( result.size() );

    memcpy( &data.front(), result.data(), result.size() );

    hasAnyData = true;
  }
  catch( std::exception & e )
  {
    setErrorString( QString::fromUtf8( e.what() ) );
  }

  finish();
}

sptr< Dictionary::DataRequest > StardictDictionary::getArticle( wstring const & word,
                                                                vector< wstring > const & alts,
                                                                wstring const &,
                                                                bool ignoreDiacritics )
  
{
  return std::make_shared<StardictArticleRequest>( word, alts, *this, ignoreDiacritics );
}


static char const * beginsWith( char const * substr, char const * str )
{
  size_t len = strlen( substr );

  return strncmp( str, substr, len ) == 0 ? str + len : 0;
}

Ifo::Ifo( File::Class & f ):
  wordcount( 0 ), synwordcount( 0 ), idxfilesize( 0 ), idxoffsetbits( 32 )
{
  static string const versionEq( "version=" );

  static string const booknameEq( "bookname=" );

  //GD_DPRINTF( "%s<\n", f.gets().c_str() );
  //GD_DPRINTF( "%s<\n", f.gets().c_str() );

  if ( QString::fromUtf8(f.gets().c_str()) != "StarDict's dict ifo file" ||
       f.gets().compare( 0, versionEq.size(), versionEq ) )
    throw exNotAnIfoFile();

  /// Now go through the file and parse options

  try
  {
    char option[ 16384 ];

    for( ; ; )
    {
      if ( !f.gets( option, sizeof( option ), true ) )
        break;

      if ( char const * val = beginsWith( "bookname=", option ) )
        bookname = val;
      else
      if ( char const * val = beginsWith( "wordcount=", option ) )
      {
        if ( sscanf( val, "%u", & wordcount ) != 1 )
          throw exBadFieldInIfo( option );
      }
      else
      if ( char const * val = beginsWith( "synwordcount=", option ) )
      {
        if ( sscanf( val, "%u", & synwordcount ) != 1 )
          throw exBadFieldInIfo( option );
      }
      else
      if ( char const * val = beginsWith( "idxfilesize=", option ) )
      {
        if ( sscanf( val, "%u", & idxfilesize ) != 1 )
          throw exBadFieldInIfo( option );
      }
      else
      if ( char const * val = beginsWith( "idxoffsetbits=", option ) )
      {
        if ( sscanf( val, "%u", & idxoffsetbits ) != 1 || ( idxoffsetbits != 32
             && idxoffsetbits != 64 ) )
          throw exBadFieldInIfo( option );
      }
      else
      if ( char const * val = beginsWith( "sametypesequence=", option ) )
        sametypesequence = val;
      else
      if ( char const * val = beginsWith( "dicttype=", option ) )
        dicttype = val;
      else
      if ( char const * val = beginsWith( "description=", option ) )
        description = val;
      else
      if ( char const * val = beginsWith( "copyright=", option ) )
        copyright = val;
      else
      if ( char const * val = beginsWith( "author=", option ) )
        author = val;
      else
      if ( char const * val = beginsWith( "email=", option ) )
        email = val;
      else
      if ( char const * val = beginsWith( "website=", option ) )
        website = val;
      else
      if ( char const * val = beginsWith( "date=", option ) )
        date = val;
    }
  }
  catch( File::exReadError & )
  {
  }
}

//// StardictDictionary::getResource()

class StardictResourceRequest;

class StardictResourceRequestRunnable: public QRunnable
{
  StardictResourceRequest & r;
  QSemaphore & hasExited;

public:

  StardictResourceRequestRunnable( StardictResourceRequest & r_,
                               QSemaphore & hasExited_ ): r( r_ ),
                                                          hasExited( hasExited_ )
  {}

  ~StardictResourceRequestRunnable()
  {
    hasExited.release();
  }

  void run() override;
};

class StardictResourceRequest: public Dictionary::DataRequest
{
  friend class StardictResourceRequestRunnable;

  StardictDictionary & dict;

  string resourceName;

  QAtomicInt isCancelled;
  QSemaphore hasExited;

public:

  StardictResourceRequest( StardictDictionary & dict_,
                      string const & resourceName_ ):
    dict( dict_ ),
    resourceName( resourceName_ )
  {
    QThreadPool::globalInstance()->start(
      new StardictResourceRequestRunnable( *this, hasExited ) );
  }

  void run(); // Run from another thread by StardictResourceRequestRunnable

  void cancel() override
  {
    isCancelled.ref();
  }

  ~StardictResourceRequest()
  {
    isCancelled.ref();
    hasExited.acquire();
  }
};

void StardictResourceRequestRunnable::run()
{
  r.run();
}

void StardictResourceRequest::run()
{
  // Some runnables linger enough that they are cancelled before they start
  if ( Utils::AtomicInt::loadAcquire( isCancelled ) )
  {
    finish();
    return;
  }

  try
  {
    if( resourceName.at( 0 ) == '\x1E' )
      resourceName = resourceName.erase( 0, 1 );
    if( resourceName.at( resourceName.length() - 1 ) == '\x1F' )
      resourceName.erase( resourceName.length() - 1, 1 );

    string n = dict.getContainingFolder().toStdString() + FsEncoding::separator() + "res" + FsEncoding::separator() + resourceName;

    GD_DPRINTF( "n is %s\n", n.c_str() );

    try
    {
      Mutex::Lock _( dataMutex );

      File::loadFromFile( n, data );
    }
    catch( File::exCantOpen & )
    {
      // Try reading from zip file

      if ( dict.resourceZip.isOpen() )
      {
        Mutex::Lock _( dict.resourceZipMutex );

        Mutex::Lock __( dataMutex );

        if ( !dict.resourceZip.loadFile( Utf8::decode( resourceName ), data ) )
          throw; // Make it fail since we couldn't read the archive
      }
      else
        throw;
    }

    if ( Filetype::isNameOfTiff( resourceName ) )
    {
      // Convert it

      Mutex::Lock _( dataMutex );
      GdTiff::tiff2img( data );
    }

    if( Filetype::isNameOfCSS( resourceName ) )
    {
      Mutex::Lock _( dataMutex );

      QString css = QString::fromUtf8( data.data(), data.size() );

      // Correct some url's

      QString id = QString::fromUtf8( dict.getId().c_str() );
      int pos = 0;

      QRegularExpression links( R"(url\(\s*(['"]?)([^'"]*)(['"]?)\s*\))",
                                QRegularExpression::CaseInsensitiveOption );

      QString newCSS;
      QRegularExpressionMatchIterator it = links.globalMatch( css );
      while( it.hasNext() )
      {
        QRegularExpressionMatch match = it.next();
        newCSS += css.mid( pos, match.capturedStart() - pos );
        pos = match.capturedEnd();

        QString url = match.captured( 2 );

        if( url.indexOf( ":/" ) >= 0 || url.indexOf( "data:" ) >= 0)
        {
          // External link
          newCSS += match.captured();
          continue;
        }

        QString newUrl = QString( "url(" ) + match.captured( 1 ) + "bres://"
                                           + id + "/" + url + match.captured( 3 ) + ")";
        newCSS += newUrl;
      }
      if( pos )
      {
        newCSS += css.mid( pos );
        css = newCSS;
        newCSS.clear();
      }

      dict.isolateCSS( css );
      QByteArray bytes = css.toUtf8();
      data.resize( bytes.size() );
      memcpy( &data.front(), bytes.constData(), bytes.size() );
    }

    Mutex::Lock _( dataMutex );
    hasAnyData = true;
  }
  catch( std::exception &ex )
  {
    gdWarning( "Stardict: Failed loading resource \"%s\" for \"%s\", reason: %s\n",
              resourceName.c_str(), dict.getName().c_str(), ex.what() );
    // Resource not loaded -- we don't set the hasAnyData flag then
  }
  catch( ... )
  {
  }

  finish();
}

sptr< Dictionary::DataRequest > StardictDictionary::getResource( string const & name )
  
{
  return std::make_shared<StardictResourceRequest>( *this, name );
}

} // anonymous namespace

static void findCorrespondingFiles( string const & ifo,
                                    string & idx, string & dict, string & syn )
{
  string base( ifo, 0, ifo.size() - 3 );

  if ( !(
          File::tryPossibleName( base + "idx", idx ) ||
          File::tryPossibleName( base + "idx.gz", idx ) ||
          File::tryPossibleName( base + "idx.dz", idx ) ||
          File::tryPossibleName( base + "IDX", idx ) ||
          File::tryPossibleName( base + "IDX.GZ", idx ) ||
          File::tryPossibleName( base + "IDX.DZ", idx )
      ) )
    throw exNoIdxFile( ifo );

  if ( !(
          File::tryPossibleName( base + "dict", dict ) ||
          File::tryPossibleName( base + "dict.dz", dict ) ||
          File::tryPossibleName( base + "DICT", dict ) ||
          File::tryPossibleName( base + "dict.DZ", dict )
      ) )
    throw exNoDictFile( ifo );

  if ( !(
         File::tryPossibleName( base + "syn", syn ) ||
         File::tryPossibleName( base + "syn.gz", syn ) ||
         File::tryPossibleName( base + "syn.dz", syn ) ||
         File::tryPossibleName( base + "SYN", syn ) ||
         File::tryPossibleName( base + "SYN.GZ", syn ) ||
         File::tryPossibleName( base + "SYN.DZ", syn )
     ) )
    syn.clear();
}

static void handleIdxSynFile( string const & fileName,
                              IndexedWords & indexedWords,
                              ChunkedStorage::Writer & chunks,
                              vector< uint32_t > * articleOffsets,
                              bool isSynFile, bool parseHeadwords )
{
  gzFile stardictIdx = gd_gzopen( fileName.c_str() );
  if ( !stardictIdx )
    throw exCantReadFile( fileName );

  vector< char > image;

  for( ; ; )
  {
    size_t oldSize = image.size();

    image.resize( oldSize + 65536 );

    int rd = gzread( stardictIdx, &image.front() + oldSize, 65536 );

    if ( rd < 0 )
    {
      gzclose( stardictIdx );
      throw exCantReadFile( fileName );
    }

    if ( rd != 65536 )
    {
      image.resize( oldSize + rd + 1 );
      break;
    }
  }
  gzclose( stardictIdx );

  // We append one zero byte to catch runaway string at the end, if any

  image.back() = 0;

  // Now parse it

  for( char const * ptr = &image.front(); ptr != &image.back(); )
  {
    size_t wordLen = strlen( ptr );

    if ( ptr + wordLen + 1 + ( isSynFile ? sizeof( uint32_t ) :
                                           sizeof( uint32_t ) * 2 ) >
         &image.back() )
    {
      GD_FDPRINTF( stderr, "Warning: sudden end of file %s\n", fileName.c_str() );
      break;
    }

    char const * word = ptr;

    ptr += wordLen + 1;

    uint32_t offset;

    if( strstr( word, "&#" ) )
    {
      // Decode some html-coded symbols in headword
      string unescapedWord = Html::unescapeUtf8( word );
      strncpy( (char *)word, unescapedWord.c_str(), wordLen );
      wordLen = strlen( word );
    }

    if ( !isSynFile )
    {
      // We're processing the .idx file
      uint32_t articleOffset, articleSize;

      memcpy( &articleOffset, ptr, sizeof( uint32_t ) );
      ptr += sizeof( uint32_t );
      memcpy( &articleSize, ptr, sizeof( uint32_t ) );
      ptr += sizeof( uint32_t );

      articleOffset = ntohl( articleOffset );
      articleSize = ntohl( articleSize );

      // Create an entry for the article in the chunked storage

      offset = chunks.startNewBlock();

      if ( articleOffsets )
        articleOffsets->push_back( offset );

      chunks.addToBlock( &articleOffset, sizeof( uint32_t ) );
      chunks.addToBlock( &articleSize, sizeof( uint32_t ) );
      chunks.addToBlock( word, wordLen + 1 );
    }
    else
    {
      // We're processing the .syn file
      uint32_t offsetInIndex;

      memcpy( &offsetInIndex, ptr, sizeof( uint32_t ) );
      ptr += sizeof( uint32_t );

      offsetInIndex = ntohl( offsetInIndex );

      if ( offsetInIndex >= articleOffsets->size() )
        throw exIncorrectOffset( fileName );

      offset = (*articleOffsets)[ offsetInIndex ];

      // Some StarDict dictionaries are in fact badly converted Babylon ones.
      // They contain a lot of superfluous slashed entries with dollar signs.
      // We try to filter them out here, since those entries become much more
      // apparent in GoldenDict than they were in StarDict because of
      // punctuation folding. Hopefully there are not a whole lot of valid
      // synonyms which really start from slash and contain dollar signs, or
      // end with dollar and contain slashes.
      if ( *word == '/' )
      {
        if ( strchr( word, '$' ) )
          continue; // Skip this entry
      }
      else
      if ( wordLen && word[ wordLen - 1 ] == '$' )
      {
        if ( strchr( word, '/' ) )
          continue; // Skip this entry
      }
    }

    // Insert new entry into an index

    if( parseHeadwords )
      indexedWords.addWord( Utf8::decode( word ), offset );
    else
      indexedWords.addSingleWord( Utf8::decode( word ), offset );
  }

  GD_DPRINTF( "%u entires made\n", (unsigned) indexedWords.size() );
}


vector< sptr< Dictionary::Class > > makeDictionaries(
                                      vector< string > const & fileNames,
                                      string const & indicesDir,
                                      Dictionary::Initializing & initializing,
                                      unsigned maxHeadwordsToExpand )
  
{
  vector< sptr< Dictionary::Class > > dictionaries;

  for( vector< string >::const_iterator i = fileNames.begin(); i != fileNames.end();
       ++i )
  {
    if ( i->size() < 4 ||
        strcasecmp( i->c_str() + ( i->size() - 4 ), ".ifo" ) != 0 )
      continue;

    try
    {
      vector< string > dictFiles( 1, *i );

      string idxFileName, dictFileName, synFileName;

      findCorrespondingFiles( *i, idxFileName, dictFileName, synFileName );

      dictFiles.push_back( idxFileName );
      dictFiles.push_back( dictFileName );

      if ( synFileName.size() )
        dictFiles.push_back( synFileName );

      // See if there's a zip file with resources present. If so, include it.

      string zipFileName;
      string baseName =
        QDir( QString::fromStdString( idxFileName ) ).absolutePath().toStdString() + FsEncoding::separator();

      if ( File::tryPossibleZipName( baseName + "res.zip", zipFileName ) ||
           File::tryPossibleZipName( baseName + "RES.ZIP", zipFileName ) ||
           File::tryPossibleZipName( baseName + "res" + FsEncoding::separator() + "res.zip", zipFileName ) )
        dictFiles.push_back( zipFileName );

      string dictId = Dictionary::makeDictionaryId( dictFiles );

      string indexFile = indicesDir + dictId;

      if ( Dictionary::needToRebuildIndex( dictFiles, indexFile ) ||
           indexIsOldOrBad( indexFile ) )
      {
        // Building the index

        File::Class ifoFile( *i, "r" );

        Ifo ifo( ifoFile );

        gdDebug( "Stardict: Building the index for dictionary: %s\n", ifo.bookname.c_str() );

        if ( ifo.idxoffsetbits == 64 )
          throw ex64BitsNotSupported();

        if ( ifo.dicttype.size() )
          throw exDicttypeNotSupported();

        if( synFileName.empty() )
        {
          if ( ifo.synwordcount )
          {
            GD_DPRINTF( "Warning: dictionary has synwordcount specified, but no "
                        "corresponding .syn file was found\n" );
            ifo.synwordcount = 0;  // Pretend it wasn't there
          }
        }
        else
        if ( !ifo.synwordcount )
        {
          GD_DPRINTF( "Warning: ignoring .syn file %s, since there's no synwordcount in .ifo specified\n",
                      synFileName.c_str() );
        }


        GD_DPRINTF( "bookname = %s\n", ifo.bookname.c_str() );
        GD_DPRINTF( "wordcount = %u\n", ifo.wordcount );

        initializing.indexingDictionary( ifo.bookname );

        File::Class idx( indexFile, "wb" );

        IdxHeader idxHeader;

        memset( &idxHeader, 0, sizeof( idxHeader ) );

        // We write a dummy header first. At the end of the process the header
        // will be rewritten with the right values.

        idx.write( idxHeader );

        idx.write( ifo.bookname.data(), ifo.bookname.size() );
        idx.write( ifo.sametypesequence.data(), ifo.sametypesequence.size() );

        IndexedWords indexedWords;

        ChunkedStorage::Writer chunks( idx );

        // Load indices
        if ( !ifo.synwordcount )
          handleIdxSynFile( idxFileName, indexedWords, chunks, 0, false,
                            !maxHeadwordsToExpand || ifo.wordcount < maxHeadwordsToExpand );
        else
        {
          vector< uint32_t > articleOffsets;

          articleOffsets.reserve( ifo.wordcount );

          handleIdxSynFile( idxFileName, indexedWords, chunks, &articleOffsets,
                            false,
                            !maxHeadwordsToExpand || ( ifo.wordcount + ifo.synwordcount ) < maxHeadwordsToExpand );

          handleIdxSynFile( synFileName, indexedWords, chunks, &articleOffsets,
                            true,
                            !maxHeadwordsToExpand || ( ifo.wordcount + ifo.synwordcount ) < maxHeadwordsToExpand );
        }

        // Finish with the chunks

        idxHeader.chunksOffset = chunks.finish();

        // Build index

        IndexInfo idxInfo = BtreeIndexing::buildIndex( indexedWords, idx );

        idxHeader.indexBtreeMaxElements = idxInfo.btreeMaxElements;
        idxHeader.indexRootOffset = idxInfo.rootOffset;

        // That concludes it. Update the header.

        idxHeader.signature = Signature;
        idxHeader.formatVersion = CurrentFormatVersion;

        idxHeader.wordCount = ifo.wordcount;
        idxHeader.synWordCount = ifo.synwordcount;
        idxHeader.bookNameSize = ifo.bookname.size();
        idxHeader.sameTypeSequenceSize = ifo.sametypesequence.size();

        // read languages
        QPair<quint32,quint32> langs =
            LangCoder::findIdsForFilename( QString::fromStdString( dictFileName ) );

        // if no languages found, try dictionary's name
        if ( langs.first == 0 || langs.second == 0 )
        {
          langs =
            LangCoder::findIdsForFilename( QString::fromStdString( ifo.bookname ) );
        }

        idxHeader.langFrom = langs.first;
        idxHeader.langTo = langs.second;

        // If there was a zip file, index it too

        if ( zipFileName.size() )
        {
          GD_DPRINTF( "Indexing zip file\n" );

          idxHeader.hasZipFile = 1;

          IndexedWords zipFileNames;
          IndexedZip zipFile;
          if ( zipFile.openZipFile( QDir::fromNativeSeparators( zipFileName.c_str() ) ) )
            zipFile.indexFile( zipFileNames );

          if( !zipFileNames.empty() )
          {
            // Build the resulting zip file index

            IndexInfo idxInfo = BtreeIndexing::buildIndex( zipFileNames, idx );

            idxHeader.zipIndexBtreeMaxElements = idxInfo.btreeMaxElements;
            idxHeader.zipIndexRootOffset = idxInfo.rootOffset;
          }
          else
          {
            // Bad zip file -- no index (though the mark that we have one
            // remains)
            idxHeader.zipIndexBtreeMaxElements = 0;
            idxHeader.zipIndexRootOffset = 0;
          }
        }
        else
          idxHeader.hasZipFile = 0;

        // That concludes it. Update the header.

        idx.rewind();

        idx.write( &idxHeader, sizeof( idxHeader ) );
      }

      dictionaries.push_back( std::make_shared<StardictDictionary>( dictId,
                                                      indexFile,
                                                      dictFiles ) );
    }
    catch( std::exception & e )
    {
      gdWarning( "Stardict dictionary initializing failed: %s, error: %s\n",
                 i->c_str(), e.what() );
    }
  }

  return dictionaries;
}


}