/***************************************************************************
    qgsstyle.cpp
    ---------------------
    begin                : November 2009
    copyright            : (C) 2009 by Martin Dobias
    email                : wonder dot sk at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#include "qgsstyle.h"

#include <sqlite3.h>

#include "qgs3dsymbolregistry.h"
#include "qgsabstract3dsymbol.h"
#include "qgsabstractmaterialsettings.h"
#include "qgsapplication.h"
#include "qgscolorramp.h"
#include "qgsfillsymbol.h"
#include "qgsfillsymbollayer.h"
#include "qgslegendpatchshape.h"
#include "qgslinestring.h"
#include "qgslinesymbol.h"
#include "qgslinesymbollayer.h"
#include "qgslogger.h"
#include "qgsmarkersymbol.h"
#include "qgsmarkersymbollayer.h"
#include "qgsmaterialregistry.h"
#include "qgspolygon.h"
#include "qgsproject.h"
#include "qgsprojectstylesettings.h"
#include "qgsreadwritecontext.h"
#include "qgsruntimeprofiler.h"
#include "qgssettings.h"
#include "qgssettingsregistrycore.h"
#include "qgssqliteutils.h"
#include "qgssymbol.h"
#include "qgssymbollayerregistry.h"

#include <QByteArray>
#include <QDomDocument>
#include <QDomElement>
#include <QDomNode>
#include <QDomNodeList>
#include <QFile>
#include <QFileInfo>
#include <QString>
#include <QTextStream>

#include "moc_qgsstyle.cpp"

using namespace Qt::StringLiterals;

#define STYLE_CURRENT_VERSION "2"

/**
 * Columns available in the legend patch table.
 */
enum LegendPatchTable
{
  LegendPatchTableId,         //!< Legend patch ID
  LegendPatchTableName,       //!< Legend patch name
  LegendPatchTableXML,        //!< Legend patch definition (as XML)
  LegendPatchTableFavoriteId, //!< Legend patch is favorite flag
};

/**
 * Columns available in the 3d symbol table.
 */
enum Symbol3DTable
{
  Symbol3DTableId,         //!< 3d symbol ID
  Symbol3DTableName,       //!< 3d symbol name
  Symbol3DTableXML,        //!< 3d symbol definition (as XML)
  Symbol3DTableFavoriteId, //!< 3d symbol is favorite flag
};

/**
 * Columns available in the 3D material settings table.
 */
enum MaterialSettingsTable
{
  MaterialSettingsTableId,         //!< 3d material settings ID
  MaterialSettingsTableName,       //!< 3d material settings name
  MaterialSettingsTableXML,        //!< 3d material settings definition (as XML)
  MaterialSettingsTableFavoriteId, //!< 3d material settings is favorite flag
};

QgsStyle *QgsStyle::sDefaultStyle = nullptr;

QgsStyle::QgsStyle( QObject *parent )
  : QObject( parent )
{
  auto simpleMarker = std::make_unique< QgsSimpleMarkerSymbolLayer >( Qgis::MarkerShape::Circle, 1.6, 0, Qgis::ScaleMethod::ScaleArea, QColor( 84, 176, 74 ), QColor( 61, 128, 53 ) );
  simpleMarker->setStrokeWidth( 0.4 );
  mPatchMarkerSymbol = std::make_unique< QgsMarkerSymbol >( QgsSymbolLayerList() << simpleMarker.release() );

  auto simpleLine = std::make_unique< QgsSimpleLineSymbolLayer >( QColor( 84, 176, 74 ), 0.6 );
  mPatchLineSymbol = std::make_unique< QgsLineSymbol >( QgsSymbolLayerList() << simpleLine.release() );

  auto gradientFill = std::make_unique< QgsGradientFillSymbolLayer >( QColor( 66, 150, 63 ), QColor( 84, 176, 74 ) );
  auto simpleOutline = std::make_unique< QgsSimpleLineSymbolLayer >( QColor( 56, 128, 54 ), 0.26 );
  mPatchFillSymbol = std::make_unique< QgsFillSymbol >( QgsSymbolLayerList() << gradientFill.release() << simpleOutline.release() );
}

QgsStyle::~QgsStyle()
{
  emit aboutToBeDestroyed();
  clear();
}

void QgsStyle::setName( const QString &name )
{
  mName = name;
}

QString QgsStyle::name() const
{
  return mName;
}

bool QgsStyle::addEntity( const QString &name, const QgsStyleEntityInterface *entity, bool update )
{
  switch ( entity->type() )
  {
    case SymbolEntity:
      if ( !static_cast< const QgsStyleSymbolEntity * >( entity )->symbol() )
        return false;
      return addSymbol( name, static_cast< const QgsStyleSymbolEntity * >( entity )->symbol()->clone(), update );

    case ColorrampEntity:
      if ( !static_cast< const QgsStyleColorRampEntity * >( entity )->ramp() )
        return false;
      return addColorRamp( name, static_cast< const QgsStyleColorRampEntity * >( entity )->ramp()->clone(), update );

    case TextFormatEntity:
      return addTextFormat( name, static_cast< const QgsStyleTextFormatEntity * >( entity )->format(), update );

    case LabelSettingsEntity:
      return addLabelSettings( name, static_cast< const QgsStyleLabelSettingsEntity * >( entity )->settings(), update );

    case LegendPatchShapeEntity:
      return addLegendPatchShape( name, static_cast< const QgsStyleLegendPatchShapeEntity * >( entity )->shape(), update );

    case Symbol3DEntity:
      return addSymbol3D( name, static_cast< const QgsStyleSymbol3DEntity * >( entity )->symbol()->clone(), update );

    case MaterialSettingsEntity:
      return addMaterialSettings( name, static_cast< const QgsStyleMaterialSettingsEntity * >( entity )->settings()->clone(), update );

    case TagEntity:
    case SmartgroupEntity:
      break;
  }
  return false;
}

QgsStyle *QgsStyle::defaultStyle( bool initialize ) // static
{
  static QString sStyleFilename;
  if ( !sDefaultStyle )
  {
    QgsScopedRuntimeProfile profile( tr( "Load default style database" ) );
    sStyleFilename = QgsApplication::userStylePath();

    // copy default style if user style doesn't exist
    if ( !QFile::exists( sStyleFilename ) )
    {
      sDefaultStyle = new QgsStyle;
      sDefaultStyle->createDatabase( sStyleFilename );
      if ( QFile::exists( QgsApplication::defaultStylePath() ) )
      {
        if ( sDefaultStyle->importXml( QgsApplication::defaultStylePath() ) )
        {
          sDefaultStyle->createStyleMetadataTableIfNeeded();
        }
      }
    }
    else
    {
      sDefaultStyle = new QgsStyle;
      sDefaultStyle->mInitialized = false;
      if ( initialize )
      {
        sDefaultStyle->initializeDefaultStyle( sStyleFilename );
      }
    }
    sDefaultStyle->setName( QObject::tr( "Default" ) );
  }
  else if ( initialize && !sDefaultStyle->mInitialized )
  {
    // lazy initialize
    sDefaultStyle->initializeDefaultStyle( sStyleFilename );
  }
  return sDefaultStyle;
}

void QgsStyle::initializeDefaultStyle( const QString &filename )
{
  Q_ASSERT( this == sDefaultStyle );
  if ( this != sDefaultStyle )
    return;

  if ( mInitialized )
    return;

  QgsScopedRuntimeProfile profile( tr( "Initialize default style database" ) );

  mInitialized = true;
  load( filename );
  upgradeIfRequired();
  emit initialized();
}

void QgsStyle::cleanDefaultStyle() // static
{
  delete sDefaultStyle;
  sDefaultStyle = nullptr;
}

void QgsStyle::clear()
{
  qDeleteAll( mSymbols );
  qDeleteAll( mColorRamps );
  qDeleteAll( m3dSymbols );
  qDeleteAll( mMaterialSettings );

  mSymbols.clear();
  mColorRamps.clear();
  mTextFormats.clear();
  m3dSymbols.clear();
  mMaterialSettings.clear();

  mCachedTags.clear();
  mCachedFavorites.clear();
}

bool QgsStyle::addSymbol( const QString &name, QgsSymbol *symbol, bool update )
{
  if ( !symbol || name.isEmpty() )
    return false;

  // delete previous symbol (if any)
  auto it = mSymbols.constFind( name );
  if ( it != mSymbols.constEnd() )
  {
    // TODO remove groups and tags?
    delete it.value();
    mSymbols.insert( name, symbol );
    if ( update )
      updateSymbol( SymbolEntity, name );
  }
  else
  {
    mSymbols.insert( name, symbol );
    if ( update )
      saveSymbol( name, symbol, false, QStringList() );
  }

  return true;
}

bool QgsStyle::saveSymbol( const QString &name, const QgsSymbol *symbol, bool favorite, const QStringList &tags )
{
  // TODO add support for groups
  QDomDocument doc( u"dummy"_s );
  QDomElement symEl = QgsSymbolLayerUtils::saveSymbol( name, symbol, doc, QgsReadWriteContext() );
  if ( symEl.isNull() )
  {
    QgsDebugError( u"Couldn't convert symbol to valid XML!"_s );
    return false;
  }

  QByteArray xmlArray;
  QTextStream stream( &xmlArray );
  symEl.save( stream, 4 );
  QString query = qgs_sqlite3_mprintf( "INSERT INTO symbol VALUES (NULL, '%q', '%q', %d);", name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );

  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Couldn't insert symbol into the database!"_s );
    return false;
  }

  mCachedFavorites[SymbolEntity].insert( name, favorite );

  tagSymbol( SymbolEntity, name, tags );

  emit symbolSaved( name, symbol );
  emit entityAdded( SymbolEntity, name );

  return true;
}

bool QgsStyle::removeSymbol( const QString &name )
{
  return removeEntityByName( SymbolEntity, name );
}

bool QgsStyle::renameEntity( QgsStyle::StyleEntity type, const QString &oldName, const QString &newName )
{
  switch ( type )
  {
    case SymbolEntity:
      return renameSymbol( oldName, newName );

    case ColorrampEntity:
      return renameColorRamp( oldName, newName );

    case TextFormatEntity:
      return renameTextFormat( oldName, newName );

    case LabelSettingsEntity:
      return renameLabelSettings( oldName, newName );

    case LegendPatchShapeEntity:
      return renameLegendPatchShape( oldName, newName );

    case Symbol3DEntity:
      return renameSymbol3D( oldName, newName );

    case MaterialSettingsEntity:
      return renameMaterialSettings( oldName, newName );

    case TagEntity:
    case SmartgroupEntity:
      return false;
  }
  return false;
}

std::unique_ptr<QgsSymbol> QgsStyle::symbol( const QString &name )
{
  const QgsSymbol *symbol = symbolRef( name );
  if ( !symbol )
    return nullptr;

  QgsSymbol *newSymbol = symbol->clone();
  QgsSymbolLayerUtils::resetSymbolLayerIds( newSymbol );

  return std::unique_ptr<QgsSymbol>( newSymbol );
}

const QgsSymbol *QgsStyle::symbolRef( const QString &name ) const
{
  return mSymbols.value( name );
}

int QgsStyle::symbolCount()
{
  return static_cast< int >( mSymbols.count() );
}

QStringList QgsStyle::symbolNames() const
{
  return mSymbols.keys();
}

bool QgsStyle::addColorRamp( const QString &name, QgsColorRamp *colorRamp, bool update )
{
  if ( !colorRamp || name.isEmpty() )
    return false;

  // delete previous color ramps (if any)
  auto it = mColorRamps.constFind( name );
  if ( it != mColorRamps.constEnd() )
  {
    // TODO remove groups and tags?
    delete it.value();
    mColorRamps.insert( name, colorRamp );
    if ( update )
      updateSymbol( ColorrampEntity, name );
  }
  else
  {
    mColorRamps.insert( name, colorRamp );
    if ( update )
      saveColorRamp( name, colorRamp, false, QStringList() );
  }

  return true;
}

bool QgsStyle::addTextFormat( const QString &name, const QgsTextFormat &format, bool update )
{
  // delete previous text format (if any)
  auto it = mTextFormats.find( name );
  if ( it != mTextFormats.end() )
  {
    // TODO remove groups and tags?
    mTextFormats.erase( it );
    mTextFormats.insert( name, format );
    if ( update )
      updateSymbol( TextFormatEntity, name );
  }
  else
  {
    mTextFormats.insert( name, format );
    if ( update )
      saveTextFormat( name, format, false, QStringList() );
  }

  return true;
}

bool QgsStyle::addLabelSettings( const QString &name, const QgsPalLayerSettings &settings, bool update )
{
  // delete previous label settings (if any)
  auto it = mLabelSettings.find( name );
  if ( it != mLabelSettings.end() )
  {
    // TODO remove groups and tags?
    mLabelSettings.erase( it );
    mLabelSettings.insert( name, settings );
    if ( update )
      updateSymbol( LabelSettingsEntity, name );
  }
  else
  {
    mLabelSettings.insert( name, settings );
    if ( update )
      saveLabelSettings( name, settings, false, QStringList() );
  }

  return true;
}

bool QgsStyle::addLegendPatchShape( const QString &name, const QgsLegendPatchShape &shape, bool update )
{
  // delete previous legend patch shape (if any)
  auto it = mLegendPatchShapes.find( name );
  if ( it != mLegendPatchShapes.end() )
  {
    // TODO remove groups and tags?
    mLegendPatchShapes.erase( it );
    mLegendPatchShapes.insert( name, shape );
    if ( update )
      updateSymbol( LegendPatchShapeEntity, name );
  }
  else
  {
    mLegendPatchShapes.insert( name, shape );
    if ( update )
      saveLegendPatchShape( name, shape, false, QStringList() );
  }

  return true;
}

bool QgsStyle::addSymbol3D( const QString &name, QgsAbstract3DSymbol *symbol, bool update )
{
  // delete previous symbol (if any)
  auto it = m3dSymbols.constFind( name );
  if ( it != m3dSymbols.constEnd() )
  {
    // TODO remove groups and tags?
    delete it.value();
    m3dSymbols.insert( name, symbol );
    if ( update )
      updateSymbol( Symbol3DEntity, name );
  }
  else
  {
    m3dSymbols.insert( name, symbol );
    if ( update )
      saveSymbol3D( name, symbol, false, QStringList() );
  }

  return true;
}

bool QgsStyle::addMaterialSettings( const QString &name, QgsAbstractMaterialSettings *settings, bool update )
{
  // delete previous settings (if any)
  auto it = mMaterialSettings.constFind( name );
  if ( it != mMaterialSettings.constEnd() )
  {
    // TODO remove groups and tags?
    delete it.value();
    mMaterialSettings.insert( name, settings );
    if ( update )
      updateSymbol( MaterialSettingsEntity, name );
  }
  else
  {
    mMaterialSettings.insert( name, settings );
    if ( update )
      saveMaterialSettings( name, settings, false, QStringList() );
  }

  return true;
}

bool QgsStyle::saveColorRamp( const QString &name, const QgsColorRamp *ramp, bool favorite, const QStringList &tags )
{
  // insert it into the database
  QDomDocument doc( u"dummy"_s );
  QDomElement rampEl = QgsSymbolLayerUtils::saveColorRamp( name, ramp, doc );

  if ( rampEl.isNull() )
  {
    QgsDebugError( u"Couldn't convert color ramp to valid XML!"_s );
    return false;
  }

  QByteArray xmlArray;
  QTextStream stream( &xmlArray );
  rampEl.save( stream, 4 );
  QString query = qgs_sqlite3_mprintf( "INSERT INTO colorramp VALUES (NULL, '%q', '%q', %d);", name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Couldn't insert colorramp into the database!"_s );
    return false;
  }

  mCachedFavorites[ColorrampEntity].insert( name, favorite );

  tagSymbol( ColorrampEntity, name, tags );

  emit rampAdded( name );
  emit entityAdded( ColorrampEntity, name );

  return true;
}

bool QgsStyle::removeColorRamp( const QString &name )
{
  return removeEntityByName( ColorrampEntity, name );
}

std::unique_ptr<QgsColorRamp> QgsStyle::colorRamp( const QString &name ) const
{
  const QgsColorRamp *ramp = colorRampRef( name );
  return std::unique_ptr<QgsColorRamp>( ramp ? ramp->clone() : nullptr );
}

const QgsColorRamp *QgsStyle::colorRampRef( const QString &name ) const
{
  return mColorRamps.value( name );
}

int QgsStyle::colorRampCount()
{
  return static_cast< int >( mColorRamps.count() );
}

QStringList QgsStyle::colorRampNames() const
{
  return mColorRamps.keys();
}

void QgsStyle::handleDeferred3DSymbolCreation()
{
  for ( auto it = mDeferred3DsymbolElements.constBegin(); it != mDeferred3DsymbolElements.constEnd(); ++it )
  {
    const QString symbolType = it.value().attribute( u"type"_s );
    std::unique_ptr< QgsAbstract3DSymbol > symbol( QgsApplication::symbol3DRegistry()->createSymbol( symbolType ) );
    if ( symbol )
    {
      symbol->readXml( it.value(), QgsReadWriteContext() );
      addSymbol3D( it.key(), symbol.release(), false );
      emit entityAdded( Symbol3DEntity, it.key() );
    }
    else
    {
      QgsDebugError( "Cannot open 3d symbol " + it.key() );
      continue;
    }
  }
  mDeferred3DsymbolElements.clear();
}

bool QgsStyle::openDatabase( const QString &filename )
{
  int rc = mCurrentDB.open( filename );
  if ( rc )
  {
    mErrorString = u"Couldn't open the style database: %1"_s.arg( mCurrentDB.errorMessage() );
    return false;
  }

  return true;
}

bool QgsStyle::createDatabase( const QString &filename )
{
  mErrorString.clear();
  if ( !openDatabase( filename ) )
  {
    mErrorString = u"Unable to create database"_s;
    QgsDebugError( mErrorString );
    return false;
  }

  createTables();

  return true;
}

bool QgsStyle::createMemoryDatabase()
{
  mErrorString.clear();
  if ( !openDatabase( u":memory:"_s ) )
  {
    mErrorString = u"Unable to create temporary memory database"_s;
    QgsDebugError( mErrorString );
    return false;
  }

  createTables();

  return true;
}

void QgsStyle::createTables()
{
  QString query = qgs_sqlite3_mprintf(
    "CREATE TABLE symbol("
    "id INTEGER PRIMARY KEY,"
    "name TEXT UNIQUE,"
    "xml TEXT,"
    "favorite INTEGER);"
    "CREATE TABLE colorramp("
    "id INTEGER PRIMARY KEY,"
    "name TEXT UNIQUE,"
    "xml TEXT,"
    "favorite INTEGER);"
    "CREATE TABLE textformat("
    "id INTEGER PRIMARY KEY,"
    "name TEXT UNIQUE,"
    "xml TEXT,"
    "favorite INTEGER);"
    "CREATE TABLE labelsettings("
    "id INTEGER PRIMARY KEY,"
    "name TEXT UNIQUE,"
    "xml TEXT,"
    "favorite INTEGER);"
    "CREATE TABLE legendpatchshapes("
    "id INTEGER PRIMARY KEY,"
    "name TEXT UNIQUE,"
    "xml TEXT,"
    "favorite INTEGER);"
    "CREATE TABLE symbol3d("
    "id INTEGER PRIMARY KEY,"
    "name TEXT UNIQUE,"
    "xml TEXT,"
    "favorite INTEGER);"
    "CREATE TABLE materialsettings("
    "id INTEGER PRIMARY KEY,"
    "name TEXT UNIQUE,"
    "xml TEXT,"
    "favorite INTEGER);"
    "CREATE TABLE tag("
    "id INTEGER PRIMARY KEY,"
    "name TEXT);"
    "CREATE TABLE tagmap("
    "tag_id INTEGER NOT NULL,"
    "symbol_id INTEGER);"
    "CREATE TABLE ctagmap("
    "tag_id INTEGER NOT NULL,"
    "colorramp_id INTEGER);"
    "CREATE TABLE tftagmap("
    "tag_id INTEGER NOT NULL,"
    "textformat_id INTEGER);"
    "CREATE TABLE lstagmap("
    "tag_id INTEGER NOT NULL,"
    "labelsettings_id INTEGER);"
    "CREATE TABLE lpstagmap("
    "tag_id INTEGER NOT NULL,"
    "legendpatchshape_id INTEGER);"
    "CREATE TABLE symbol3dtagmap("
    "tag_id INTEGER NOT NULL,"
    "symbol3d_id INTEGER);"
    "CREATE TABLE materialsettingstagmap("
    "tag_id INTEGER NOT NULL,"
    "materialsettings_id INTEGER);"
    "CREATE TABLE smartgroup("
    "id INTEGER PRIMARY KEY,"
    "name TEXT,"
    "xml TEXT);"
  );
  runEmptyQuery( query );
}

bool QgsStyle::load( const QString &filename )
{
  mErrorString.clear();

  // Open the sqlite database
  if ( !openDatabase( filename ) )
  {
    mErrorString = u"Unable to open database file specified"_s;
    QgsDebugError( mErrorString );
    return false;
  }

  // make sure text format table exists
  QString query = qgs_sqlite3_mprintf( "SELECT name FROM sqlite_master WHERE name='textformat'" );
  sqlite3_statement_unique_ptr statement;
  int rc;
  statement = mCurrentDB.prepare( query, rc );
  if ( rc != SQLITE_OK || sqlite3_step( statement.get() ) != SQLITE_ROW )
  {
    query = qgs_sqlite3_mprintf(
      "CREATE TABLE textformat("
      "id INTEGER PRIMARY KEY,"
      "name TEXT UNIQUE,"
      "xml TEXT,"
      "favorite INTEGER);"
      "CREATE TABLE tftagmap("
      "tag_id INTEGER NOT NULL,"
      "textformat_id INTEGER);"
    );
    runEmptyQuery( query );
  }
  // make sure label settings table exists
  query = qgs_sqlite3_mprintf( "SELECT name FROM sqlite_master WHERE name='labelsettings'" );
  statement = mCurrentDB.prepare( query, rc );
  if ( rc != SQLITE_OK || sqlite3_step( statement.get() ) != SQLITE_ROW )
  {
    query = qgs_sqlite3_mprintf(
      "CREATE TABLE labelsettings("
      "id INTEGER PRIMARY KEY,"
      "name TEXT UNIQUE,"
      "xml TEXT,"
      "favorite INTEGER);"
      "CREATE TABLE lstagmap("
      "tag_id INTEGER NOT NULL,"
      "labelsettings_id INTEGER);"
    );
    runEmptyQuery( query );
  }
  // make sure legend patch shape table exists
  query = qgs_sqlite3_mprintf( "SELECT name FROM sqlite_master WHERE name='legendpatchshapes'" );
  statement = mCurrentDB.prepare( query, rc );
  if ( rc != SQLITE_OK || sqlite3_step( statement.get() ) != SQLITE_ROW )
  {
    query = qgs_sqlite3_mprintf(
      "CREATE TABLE legendpatchshapes("
      "id INTEGER PRIMARY KEY,"
      "name TEXT UNIQUE,"
      "xml TEXT,"
      "favorite INTEGER);"
      "CREATE TABLE lpstagmap("
      "tag_id INTEGER NOT NULL,"
      "legendpatchshape_id INTEGER);"
    );
    runEmptyQuery( query );
  }
  // make sure 3d symbol table exists
  query = qgs_sqlite3_mprintf( "SELECT name FROM sqlite_master WHERE name='symbol3d'" );
  statement = mCurrentDB.prepare( query, rc );
  if ( rc != SQLITE_OK || sqlite3_step( statement.get() ) != SQLITE_ROW )
  {
    query = qgs_sqlite3_mprintf(
      "CREATE TABLE symbol3d("
      "id INTEGER PRIMARY KEY,"
      "name TEXT UNIQUE,"
      "xml TEXT,"
      "favorite INTEGER);"
      "CREATE TABLE symbol3dtagmap("
      "tag_id INTEGER NOT NULL,"
      "symbol3d_id INTEGER);"
    );
    runEmptyQuery( query );
  }

  // make sure 3D material settings table exists
  query = qgs_sqlite3_mprintf( "SELECT name FROM sqlite_master WHERE name='materialsettings'" );
  statement = mCurrentDB.prepare( query, rc );
  if ( rc != SQLITE_OK || sqlite3_step( statement.get() ) != SQLITE_ROW )
  {
    query = qgs_sqlite3_mprintf(
      "CREATE TABLE materialsettings("
      "id INTEGER PRIMARY KEY,"
      "name TEXT UNIQUE,"
      "xml TEXT,"
      "favorite INTEGER);"
      "CREATE TABLE materialsettingstagmap("
      "tag_id INTEGER NOT NULL,"
      "materialsettings_id INTEGER);"
    );
    runEmptyQuery( query );
  }

  // Make sure there are no Null fields in parenting symbols and groups
  query = qgs_sqlite3_mprintf(
    "UPDATE symbol SET favorite=0 WHERE favorite IS NULL;"
    "UPDATE colorramp SET favorite=0 WHERE favorite IS NULL;"
    "UPDATE textformat SET favorite=0 WHERE favorite IS NULL;"
    "UPDATE labelsettings SET favorite=0 WHERE favorite IS NULL;"
    "UPDATE legendpatchshapes SET favorite=0 WHERE favorite IS NULL;"
    "UPDATE symbol3d SET favorite=0 WHERE favorite IS NULL;"
    "UPDATE materialsettings SET favorite=0 WHERE favorite IS NULL;"
  );
  runEmptyQuery( query );

  {
    QgsScopedRuntimeProfile profile( tr( "Load symbols" ) );
    // First create all the main symbols
    query = qgs_sqlite3_mprintf( "SELECT * FROM symbol" );
    statement = mCurrentDB.prepare( query, rc );

    while ( rc == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      QDomDocument doc;
      QString symbolName = statement.columnAsText( static_cast< int >( SymbolTableColumn::Name ) );
      QgsScopedRuntimeProfile profile( symbolName );
      QString xmlstring = statement.columnAsText( static_cast< int >( SymbolTableColumn::XML ) );
      if ( !doc.setContent( xmlstring ) )
      {
        QgsDebugError( "Cannot open symbol " + symbolName );
        continue;
      }

      QDomElement symElement = doc.documentElement();
      std::unique_ptr< QgsSymbol > symbol = QgsSymbolLayerUtils::loadSymbol( symElement, QgsReadWriteContext() );
      if ( symbol )
        mSymbols.insert( symbolName, symbol.release() );
    }
  }

  {
    QgsScopedRuntimeProfile profile( tr( "Load color ramps" ) );
    query = qgs_sqlite3_mprintf( "SELECT * FROM colorramp" );
    statement = mCurrentDB.prepare( query, rc );
    while ( rc == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      QDomDocument doc;
      const QString rampName = statement.columnAsText( static_cast< int >( ColorRampTableColumn::Name ) );
      QgsScopedRuntimeProfile profile( rampName );
      QString xmlstring = statement.columnAsText( static_cast< int >( ColorRampTableColumn::XML ) );
      if ( !doc.setContent( xmlstring ) )
      {
        QgsDebugError( "Cannot open symbol " + rampName );
        continue;
      }
      QDomElement rampElement = doc.documentElement();
      std::unique_ptr< QgsColorRamp > ramp = QgsSymbolLayerUtils::loadColorRamp( rampElement );
      if ( ramp )
        mColorRamps.insert( rampName, ramp.release() );
    }
  }

  {
    QgsScopedRuntimeProfile profile( tr( "Load text formats" ) );
    query = qgs_sqlite3_mprintf( "SELECT * FROM textformat" );
    statement = mCurrentDB.prepare( query, rc );
    while ( rc == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      QDomDocument doc;
      const QString formatName = statement.columnAsText( static_cast< int >( TextFormatTableColumn::Name ) );
      QgsScopedRuntimeProfile profile( formatName );
      const QString xmlstring = statement.columnAsText( static_cast< int >( TextFormatTableColumn::XML ) );
      if ( !doc.setContent( xmlstring ) )
      {
        QgsDebugError( "Cannot open text format " + formatName );
        continue;
      }
      QDomElement formatElement = doc.documentElement();
      QgsTextFormat format;
      format.readXml( formatElement, QgsReadWriteContext() );
      mTextFormats.insert( formatName, format );
    }
  }

  {
    QgsScopedRuntimeProfile profile( tr( "Load label settings" ) );
    query = qgs_sqlite3_mprintf( "SELECT * FROM labelsettings" );
    statement = mCurrentDB.prepare( query, rc );
    while ( rc == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      QDomDocument doc;
      const QString settingsName = statement.columnAsText( static_cast< int >( LabelSettingsTableColumn::Name ) );
      QgsScopedRuntimeProfile profile( settingsName );
      const QString xmlstring = statement.columnAsText( static_cast< int >( LabelSettingsTableColumn::XML ) );
      if ( !doc.setContent( xmlstring ) )
      {
        QgsDebugError( "Cannot open label settings " + settingsName );
        continue;
      }
      QDomElement settingsElement = doc.documentElement();
      QgsPalLayerSettings settings;
      settings.readXml( settingsElement, QgsReadWriteContext() );
      mLabelSettings.insert( settingsName, settings );
    }
  }

  {
    QgsScopedRuntimeProfile profile( tr( "Load legend patch shapes" ) );
    query = qgs_sqlite3_mprintf( "SELECT * FROM legendpatchshapes" );
    statement = mCurrentDB.prepare( query, rc );
    while ( rc == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      QDomDocument doc;
      const QString settingsName = statement.columnAsText( LegendPatchTableName );
      QgsScopedRuntimeProfile profile( settingsName );
      const QString xmlstring = statement.columnAsText( LegendPatchTableXML );
      if ( !doc.setContent( xmlstring ) )
      {
        QgsDebugError( "Cannot open legend patch shape " + settingsName );
        continue;
      }
      QDomElement settingsElement = doc.documentElement();
      QgsLegendPatchShape shape;
      shape.readXml( settingsElement, QgsReadWriteContext() );
      mLegendPatchShapes.insert( settingsName, shape );
    }
  }

  {
    QgsScopedRuntimeProfile profile( tr( "Load 3D symbols" ) );
    query = qgs_sqlite3_mprintf( "SELECT * FROM symbol3d" );
    statement = mCurrentDB.prepare( query, rc );

    const bool registry3dPopulated = !QgsApplication::symbol3DRegistry()->symbolTypes().empty();

    while ( rc == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      QDomDocument doc;
      const QString settingsName = statement.columnAsText( Symbol3DTableName );
      QgsScopedRuntimeProfile profile( settingsName );
      const QString xmlstring = statement.columnAsText( Symbol3DTableXML );
      if ( !doc.setContent( xmlstring ) )
      {
        QgsDebugError( "Cannot open 3d symbol " + settingsName );
        continue;
      }
      QDomElement settingsElement = doc.documentElement();

      if ( !registry3dPopulated )
      {
        mDeferred3DsymbolElements.insert( settingsName, settingsElement );
      }
      else
      {
        const QString symbolType = settingsElement.attribute( u"type"_s );
        std::unique_ptr< QgsAbstract3DSymbol > symbol( QgsApplication::symbol3DRegistry()->createSymbol( symbolType ) );
        if ( symbol )
        {
          symbol->readXml( settingsElement, QgsReadWriteContext() );
          m3dSymbols.insert( settingsName, symbol.release() );
        }
        else
        {
          QgsDebugError( "Cannot open 3d symbol " + settingsName );
          continue;
        }
      }
    }
  }

  {
    QgsScopedRuntimeProfile profile( tr( "Load material settings" ) );
    query = qgs_sqlite3_mprintf( "SELECT * FROM materialsettings" );
    statement = mCurrentDB.prepare( query, rc );

    while ( rc == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      QDomDocument doc;
      const QString settingsName = statement.columnAsText( MaterialSettingsTableName );
      QgsScopedRuntimeProfile profile( settingsName );
      const QString xmlstring = statement.columnAsText( MaterialSettingsTableXML );
      if ( !doc.setContent( xmlstring ) )
      {
        QgsDebugError( "Cannot open material settings " + settingsName );
        continue;
      }
      QDomElement settingsElement = doc.documentElement();

      const QString materialType = settingsElement.attribute( u"type"_s );
      std::unique_ptr< QgsAbstractMaterialSettings > settings = QgsApplication::materialRegistry()->createMaterialSettings( materialType );
      if ( settings )
      {
        settings->readXml( settingsElement, QgsReadWriteContext() );
        mMaterialSettings.insert( settingsName, settings.release() );
      }
      else
      {
        QgsDebugError( "Cannot open material settings " + settingsName );
        continue;
      }
    }
  }

  mFileName = filename;
  createStyleMetadataTableIfNeeded();
  return true;
}

bool QgsStyle::save( const QString &filename )
{
  mErrorString.clear();

  if ( !filename.isEmpty() )
    mFileName = filename;

  return true;
}

void QgsStyle::setFileName( const QString &filename )
{
  mFileName = filename;
}

bool QgsStyle::renameSymbol( const QString &oldName, const QString &newName )
{
  if ( mSymbols.contains( newName ) )
  {
    QgsDebugError( u"Symbol of new name already exists"_s );
    return false;
  }

  QgsSymbol *symbol = mSymbols.take( oldName );
  if ( !symbol )
    return false;

  mSymbols.insert( newName, symbol );

  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database to tag."_s );
    return false;
  }

  int symbolid = symbolId( oldName );
  if ( !symbolid )
  {
    QgsDebugError( u"No such symbol for tagging in database: "_s + oldName );
    return false;
  }

  mCachedTags[SymbolEntity].remove( oldName );
  mCachedFavorites[SymbolEntity].remove( oldName );

  const bool result = rename( SymbolEntity, symbolid, newName );
  if ( result )
  {
    emit symbolRenamed( oldName, newName );
    emit entityRenamed( SymbolEntity, oldName, newName );
  }

  return result;
}

bool QgsStyle::renameColorRamp( const QString &oldName, const QString &newName )
{
  if ( mColorRamps.contains( newName ) )
  {
    QgsDebugError( u"Color ramp of new name already exists."_s );
    return false;
  }

  QgsColorRamp *ramp = mColorRamps.take( oldName );
  if ( !ramp )
    return false;

  mColorRamps.insert( newName, ramp );
  mCachedTags[ColorrampEntity].remove( oldName );
  mCachedFavorites[ColorrampEntity].remove( oldName );

  int rampid = 0;
  sqlite3_statement_unique_ptr statement;
  QString query = qgs_sqlite3_mprintf( "SELECT id FROM colorramp WHERE name='%q'", oldName.toUtf8().constData() );
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );
  if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    rampid = sqlite3_column_int( statement.get(), 0 );
  }
  const bool result = rename( ColorrampEntity, rampid, newName );
  if ( result )
  {
    emit rampRenamed( oldName, newName );
    emit entityRenamed( ColorrampEntity, oldName, newName );
  }

  return result;
}

bool QgsStyle::saveTextFormat( const QString &name, const QgsTextFormat &format, bool favorite, const QStringList &tags )
{
  // insert it into the database
  QDomDocument doc( u"dummy"_s );
  QDomElement formatElem = format.writeXml( doc, QgsReadWriteContext() );

  if ( formatElem.isNull() )
  {
    QgsDebugError( u"Couldn't convert text format to valid XML!"_s );
    return false;
  }

  QByteArray xmlArray;
  QTextStream stream( &xmlArray );
  formatElem.save( stream, 4 );
  QString query = qgs_sqlite3_mprintf( "INSERT INTO textformat VALUES (NULL, '%q', '%q', %d);", name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Couldn't insert text format into the database!"_s );
    return false;
  }

  mCachedFavorites[TextFormatEntity].insert( name, favorite );

  tagSymbol( TextFormatEntity, name, tags );

  emit textFormatAdded( name );
  emit entityAdded( TextFormatEntity, name );

  return true;
}

bool QgsStyle::removeTextFormat( const QString &name )
{
  return removeEntityByName( TextFormatEntity, name );
}

bool QgsStyle::renameTextFormat( const QString &oldName, const QString &newName )
{
  if ( mTextFormats.contains( newName ) )
  {
    QgsDebugError( u"Text format of new name already exists."_s );
    return false;
  }

  if ( !mTextFormats.contains( oldName ) )
    return false;
  QgsTextFormat format = mTextFormats.take( oldName );

  mTextFormats.insert( newName, format );
  mCachedTags[TextFormatEntity].remove( oldName );
  mCachedFavorites[TextFormatEntity].remove( oldName );

  int textFormatId = 0;
  sqlite3_statement_unique_ptr statement;
  QString query = qgs_sqlite3_mprintf( "SELECT id FROM textformat WHERE name='%q'", oldName.toUtf8().constData() );
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );
  if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    textFormatId = sqlite3_column_int( statement.get(), 0 );
  }
  const bool result = rename( TextFormatEntity, textFormatId, newName );
  if ( result )
  {
    emit textFormatRenamed( oldName, newName );
    emit entityRenamed( TextFormatEntity, oldName, newName );
  }

  return result;
}

bool QgsStyle::saveLabelSettings( const QString &name, const QgsPalLayerSettings &settings, bool favorite, const QStringList &tags )
{
  // insert it into the database
  QDomDocument doc( u"dummy"_s );
  QDomElement settingsElem = settings.writeXml( doc, QgsReadWriteContext() );

  if ( settingsElem.isNull() )
  {
    QgsDebugError( u"Couldn't convert label settings to valid XML!"_s );
    return false;
  }

  QByteArray xmlArray;
  QTextStream stream( &xmlArray );
  settingsElem.save( stream, 4 );
  QString query = qgs_sqlite3_mprintf( "INSERT INTO labelsettings VALUES (NULL, '%q', '%q', %d);", name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Couldn't insert label settings into the database!"_s );
    return false;
  }

  mCachedFavorites[LabelSettingsEntity].insert( name, favorite );

  tagSymbol( LabelSettingsEntity, name, tags );

  emit labelSettingsAdded( name );
  emit entityAdded( LabelSettingsEntity, name );

  return true;
}

bool QgsStyle::removeLabelSettings( const QString &name )
{
  return removeEntityByName( LabelSettingsEntity, name );
}

bool QgsStyle::renameLabelSettings( const QString &oldName, const QString &newName )
{
  if ( mLabelSettings.contains( newName ) )
  {
    QgsDebugError( u"Label settings of new name already exists."_s );
    return false;
  }

  if ( !mLabelSettings.contains( oldName ) )
    return false;
  QgsPalLayerSettings settings = mLabelSettings.take( oldName );

  mLabelSettings.insert( newName, settings );
  mCachedTags[LabelSettingsEntity].remove( oldName );
  mCachedFavorites[LabelSettingsEntity].remove( oldName );

  int labelSettingsId = 0;
  sqlite3_statement_unique_ptr statement;
  QString query = qgs_sqlite3_mprintf( "SELECT id FROM labelsettings WHERE name='%q'", oldName.toUtf8().constData() );
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );
  if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    labelSettingsId = sqlite3_column_int( statement.get(), 0 );
  }
  const bool result = rename( LabelSettingsEntity, labelSettingsId, newName );
  if ( result )
  {
    emit labelSettingsRenamed( oldName, newName );
    emit entityRenamed( LabelSettingsEntity, oldName, newName );
  }

  return result;
}

bool QgsStyle::saveLegendPatchShape( const QString &name, const QgsLegendPatchShape &shape, bool favorite, const QStringList &tags )
{
  // insert it into the database
  QDomDocument doc( u"dummy"_s );
  QDomElement shapeElem = doc.createElement( u"shape"_s );
  shape.writeXml( shapeElem, doc, QgsReadWriteContext() );

  QByteArray xmlArray;
  QTextStream stream( &xmlArray );
  shapeElem.save( stream, 4 );
  QString query = qgs_sqlite3_mprintf( "INSERT INTO legendpatchshapes VALUES (NULL, '%q', '%q', %d);", name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Couldn't insert legend patch shape into the database!"_s );
    return false;
  }

  mCachedFavorites[LegendPatchShapeEntity].insert( name, favorite );

  tagSymbol( LegendPatchShapeEntity, name, tags );

  emit entityAdded( LegendPatchShapeEntity, name );

  return true;
}

bool QgsStyle::renameLegendPatchShape( const QString &oldName, const QString &newName )
{
  if ( mLegendPatchShapes.contains( newName ) )
  {
    QgsDebugError( u"Legend patch shape of new name already exists."_s );
    return false;
  }

  if ( !mLegendPatchShapes.contains( oldName ) )
    return false;
  QgsLegendPatchShape shape = mLegendPatchShapes.take( oldName );

  mLegendPatchShapes.insert( newName, shape );
  mCachedTags[LegendPatchShapeEntity].remove( oldName );
  mCachedFavorites[LegendPatchShapeEntity].remove( oldName );

  int labelSettingsId = 0;
  sqlite3_statement_unique_ptr statement;
  QString query = qgs_sqlite3_mprintf( "SELECT id FROM legendpatchshapes WHERE name='%q'", oldName.toUtf8().constData() );
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );
  if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    labelSettingsId = sqlite3_column_int( statement.get(), 0 );
  }
  const bool result = rename( LegendPatchShapeEntity, labelSettingsId, newName );
  if ( result )
  {
    emit entityRenamed( LegendPatchShapeEntity, oldName, newName );
  }

  return result;
}

QgsLegendPatchShape QgsStyle::defaultPatch( Qgis::SymbolType type, QSizeF size ) const
{
  if ( type == Qgis::SymbolType::Hybrid )
    return QgsLegendPatchShape();

  auto it = mDefaultPatchCache[static_cast< int >( type )].constFind( size );
  if ( it != mDefaultPatchCache[static_cast< int >( type )].constEnd() )
    return it.value();

  QgsGeometry geom;
  switch ( type )
  {
    case Qgis::SymbolType::Marker:
      geom = QgsGeometry( std::make_unique< QgsPoint >( static_cast< int >( size.width() ) / 2, static_cast< int >( size.height() ) / 2 ) );
      break;

    case Qgis::SymbolType::Line:
    {
      // we're adding 0.5 to get rid of blurred preview:
      // drawing antialiased lines of width 1 at (x,0)-(x,100) creates 2px line
      double y = static_cast< int >( size.height() ) / 2 + 0.5;
      geom = QgsGeometry( std::make_unique< QgsLineString >( ( QVector< double >() << 0 << size.width() ), ( QVector< double >() << y << y ) ) );
      break;
    }

    case Qgis::SymbolType::Fill:
    {
      geom = QgsGeometry(
        std::make_unique< QgsPolygon >( new QgsLineString(
          QVector< double >() << 0 << static_cast< int >( size.width() ) << static_cast< int >( size.width() ) << 0 << 0,
          QVector< double >() << static_cast< int >( size.height() ) << static_cast< int >( size.height() ) << 0 << 0 << static_cast< int >( size.height() )
        ) )
      );
      break;
    }

    case Qgis::SymbolType::Hybrid:
      break;
  }

  QgsLegendPatchShape res = QgsLegendPatchShape( type, geom, false );
  mDefaultPatchCache[static_cast< int >( type )][size] = res;
  return res;
}

QList<QList<QPolygonF> > QgsStyle::defaultPatchAsQPolygonF( Qgis::SymbolType type, QSizeF size ) const
{
  if ( type == Qgis::SymbolType::Hybrid )
    return QList<QList<QPolygonF> >();

  auto it = mDefaultPatchQPolygonFCache[static_cast< int >( type )].constFind( size );
  if ( it != mDefaultPatchQPolygonFCache[static_cast< int >( type )].constEnd() )
    return it.value();

  QList<QList<QPolygonF> > res = defaultPatch( type, size ).toQPolygonF( type, size );
  mDefaultPatchQPolygonFCache[static_cast< int >( type )][size] = res;
  return res;
}

QgsTextFormat QgsStyle::defaultTextFormat( QgsStyle::TextFormatContext ) const
{
  return textFormat( u"Default"_s );
}

QgsTextFormat QgsStyle::defaultTextFormatForProject( QgsProject *project, TextFormatContext context )
{
  if ( project )
  {
    QgsTextFormat defaultTextFormat = project->styleSettings()->defaultTextFormat();
    if ( defaultTextFormat.isValid() )
    {
      return defaultTextFormat;
    }
  }

  return QgsStyle::defaultStyle()->defaultTextFormat( context );
}

bool QgsStyle::saveSymbol3D( const QString &name, QgsAbstract3DSymbol *symbol, bool favorite, const QStringList &tags )
{
  // insert it into the database
  QDomDocument doc( u"dummy"_s );
  QDomElement elem = doc.createElement( u"symbol"_s );
  elem.setAttribute( u"type"_s, symbol->type() );
  symbol->writeXml( elem, QgsReadWriteContext() );

  QByteArray xmlArray;
  QTextStream stream( &xmlArray );
  elem.save( stream, 4 );
  QString query = qgs_sqlite3_mprintf( "INSERT INTO symbol3d VALUES (NULL, '%q', '%q', %d);", name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Couldn't insert 3d symbol into the database!"_s );
    return false;
  }

  mCachedFavorites[Symbol3DEntity].insert( name, favorite );

  tagSymbol( Symbol3DEntity, name, tags );

  emit entityAdded( Symbol3DEntity, name );

  return true;
}

bool QgsStyle::renameSymbol3D( const QString &oldName, const QString &newName )
{
  if ( m3dSymbols.contains( newName ) )
  {
    QgsDebugError( u"3d symbol of new name already exists."_s );
    return false;
  }

  if ( !m3dSymbols.contains( oldName ) )
    return false;
  QgsAbstract3DSymbol *symbol = m3dSymbols.take( oldName );

  m3dSymbols.insert( newName, symbol );
  mCachedTags[Symbol3DEntity].remove( oldName );
  mCachedFavorites[Symbol3DEntity].remove( oldName );

  int labelSettingsId = 0;
  sqlite3_statement_unique_ptr statement;
  QString query = qgs_sqlite3_mprintf( "SELECT id FROM symbol3d WHERE name='%q'", oldName.toUtf8().constData() );
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );
  if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    labelSettingsId = sqlite3_column_int( statement.get(), 0 );
  }
  const bool result = rename( Symbol3DEntity, labelSettingsId, newName );
  if ( result )
  {
    emit entityRenamed( Symbol3DEntity, oldName, newName );
  }

  return result;
}

QStringList QgsStyle::symbol3DNames() const
{
  return m3dSymbols.keys();
}

bool QgsStyle::saveMaterialSettings( const QString &name, QgsAbstractMaterialSettings *settings, bool favorite, const QStringList &tags )
{
  // insert it into the database
  QDomDocument doc( u"dummy"_s );
  QDomElement elem = doc.createElement( u"settings"_s );
  elem.setAttribute( u"type"_s, settings->type() );
  settings->writeXml( elem, QgsReadWriteContext() );

  QByteArray xmlArray;
  QTextStream stream( &xmlArray );
  elem.save( stream, 4 );
  QString query = qgs_sqlite3_mprintf( "INSERT INTO materialsettings VALUES (NULL, '%q', '%q', %d);", name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Couldn't insert material settings into the database!"_s );
    return false;
  }

  mCachedFavorites[MaterialSettingsEntity].insert( name, favorite );

  tagSymbol( MaterialSettingsEntity, name, tags );

  emit entityAdded( MaterialSettingsEntity, name );

  return true;
}

bool QgsStyle::renameMaterialSettings( const QString &oldName, const QString &newName )
{
  if ( mMaterialSettings.contains( newName ) )
  {
    QgsDebugError( u"material settings of new name already exists."_s );
    return false;
  }

  if ( !mMaterialSettings.contains( oldName ) )
    return false;
  std::unique_ptr< QgsAbstractMaterialSettings > settings( mMaterialSettings.take( oldName ) );

  mMaterialSettings.insert( newName, settings.release() );
  mCachedTags[MaterialSettingsEntity].remove( oldName );
  mCachedFavorites[MaterialSettingsEntity].remove( oldName );

  int materialSettingsId = 0;
  sqlite3_statement_unique_ptr statement;
  QString query = qgs_sqlite3_mprintf( "SELECT id FROM materialsettings WHERE name='%q'", oldName.toUtf8().constData() );
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );
  if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    materialSettingsId = sqlite3_column_int( statement.get(), 0 );
  }
  const bool result = rename( MaterialSettingsEntity, materialSettingsId, newName );
  if ( result )
  {
    emit entityRenamed( MaterialSettingsEntity, oldName, newName );
  }

  return result;
}

QStringList QgsStyle::materialSettingsNames() const
{
  return mMaterialSettings.keys();
}

int QgsStyle::materialSettingsCount() const
{
  return static_cast< int >( mMaterialSettings.size() );
}

std::unique_ptr< QgsAbstractMaterialSettings > QgsStyle::materialSettings( const QString &name ) const
{
  auto it = mMaterialSettings.constFind( name );
  if ( it != mMaterialSettings.constEnd() )
    return std::unique_ptr< QgsAbstractMaterialSettings >( it.value()->clone() );
  return nullptr;
}

QStringList QgsStyle::symbolsOfFavorite( StyleEntity type ) const
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Cannot Open database for getting favorite symbols"_s );
    return QStringList();
  }

  QString query;
  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      QgsDebugError( u"No such style entity"_s );
      return QStringList();

    default:
      query = qgs_sqlite3_mprintf( u"SELECT name FROM %1 WHERE favorite=1"_s.arg( entityTableName( type ) ).toLocal8Bit().data() );
      break;
  }

  int nErr;
  sqlite3_statement_unique_ptr statement;
  statement = mCurrentDB.prepare( query, nErr );

  QStringList symbols;
  while ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    symbols << statement.columnAsText( 0 );
  }

  return symbols;
}

QStringList QgsStyle::symbolsWithTag( StyleEntity type, int tagid ) const
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Cannot open database to get symbols of tagid %1"_s.arg( tagid ) );
    return QStringList();
  }

  QString subquery;
  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      QgsDebugError( u"Unknown Entity"_s );
      return QStringList();

    default:
      subquery = qgs_sqlite3_mprintf( u"SELECT %1 FROM %2 WHERE tag_id=%d"_s.arg( tagmapEntityIdFieldName( type ), tagmapTableName( type ) ).toLocal8Bit().data(), tagid );
      break;
  }

  int nErr;
  sqlite3_statement_unique_ptr statement;
  statement = mCurrentDB.prepare( subquery, nErr );

  // get the symbol <-> tag connection from the tag map table
  QStringList symbols;
  while ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    int id = sqlite3_column_int( statement.get(), 0 );

    const QString query = qgs_sqlite3_mprintf( u"SELECT name FROM %1 WHERE id=%d"_s.arg( entityTableName( type ) ).toLocal8Bit().data(), id );

    int rc;
    sqlite3_statement_unique_ptr statement2;
    statement2 = mCurrentDB.prepare( query, rc );
    while ( rc == SQLITE_OK && sqlite3_step( statement2.get() ) == SQLITE_ROW )
    {
      symbols << statement2.columnAsText( 0 );
    }
  }

  return symbols;
}

int QgsStyle::addTag( const QString &tagname )
{
  if ( !mCurrentDB )
    return 0;
  sqlite3_statement_unique_ptr statement;

  QString query = qgs_sqlite3_mprintf( "INSERT INTO tag VALUES (NULL, '%q')", tagname.toUtf8().constData() );
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );
  if ( nErr == SQLITE_OK )
    ( void ) sqlite3_step( statement.get() );

  QgsSettingsRegistryCore::settingsSymbolsListGroupsIndex->setValue( 0 );

  emit groupsModified();

  return static_cast< int >( sqlite3_last_insert_rowid( mCurrentDB.get() ) );
}

QStringList QgsStyle::tags() const
{
  if ( !mCurrentDB )
    return QStringList();

  sqlite3_statement_unique_ptr statement;

  QString query = qgs_sqlite3_mprintf( "SELECT name FROM tag" );
  int nError;
  statement = mCurrentDB.prepare( query, nError );

  QStringList tagList;
  while ( nError == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    tagList << statement.columnAsText( 0 );
  }

  return tagList;
}

bool QgsStyle::rename( StyleEntity type, int id, const QString &newName )
{
  const QString query = qgs_sqlite3_mprintf( u"UPDATE %1 SET name='%q' WHERE id=%d"_s.arg( entityTableName( type ) ).toLocal8Bit().data(), newName.toUtf8().constData(), id );

  const bool result = runEmptyQuery( query );
  if ( !result )
  {
    mErrorString = u"Could not rename!"_s;
  }
  else
  {
    mCachedTags.clear();
    mCachedFavorites.clear();

    switch ( type )
    {
      case TagEntity:
      {
        emit groupsModified();
        break;
      }

      case SmartgroupEntity:
      {
        emit groupsModified();
        break;
      }

      default:
        break;
    }
  }
  return result;
}

bool QgsStyle::remove( StyleEntity type, int id )
{
  bool groupRemoved = false;
  QString query;
  switch ( type )
  {
    case TagEntity:
      query = qgs_sqlite3_mprintf( "DELETE FROM tag WHERE id=%d; DELETE FROM tagmap WHERE tag_id=%d", id, id );
      groupRemoved = true;
      break;
    case SmartgroupEntity:
      query = qgs_sqlite3_mprintf( "DELETE FROM smartgroup WHERE id=%d", id );
      groupRemoved = true;
      break;

    default:
      query
        = qgs_sqlite3_mprintf( u"DELETE FROM %1 WHERE id=%d; DELETE FROM %2 WHERE %3=%d"_s.arg( entityTableName( type ), tagmapTableName( type ), tagmapEntityIdFieldName( type ) ).toLocal8Bit().data(), id, id );
      break;
  }

  bool result = false;
  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Could not delete entity!"_s );
  }
  else
  {
    mCachedTags.clear();
    mCachedFavorites.clear();

    if ( groupRemoved )
    {
      QgsSettingsRegistryCore::settingsSymbolsListGroupsIndex->setValue( 0 );

      emit groupsModified();
    }
    result = true;
  }
  return result;
}

bool QgsStyle::removeEntityByName( QgsStyle::StyleEntity type, const QString &name )
{
  switch ( type )
  {
    case QgsStyle::TagEntity:
    case QgsStyle::SmartgroupEntity:
      return false;

    case QgsStyle::SymbolEntity:
    {
      std::unique_ptr< QgsSymbol > symbol( mSymbols.take( name ) );
      if ( !symbol )
        return false;

      break;
    }

    case QgsStyle::Symbol3DEntity:
    {
      std::unique_ptr< QgsAbstract3DSymbol > symbol( m3dSymbols.take( name ) );
      if ( !symbol )
        return false;

      break;
    }

    case QgsStyle::MaterialSettingsEntity:
    {
      std::unique_ptr< QgsAbstractMaterialSettings > settings( mMaterialSettings.take( name ) );
      if ( !settings )
        return false;

      break;
    }

    case QgsStyle::ColorrampEntity:
    {
      std::unique_ptr< QgsColorRamp > ramp( mColorRamps.take( name ) );
      if ( !ramp )
        return false;
      break;
    }

    case QgsStyle::TextFormatEntity:
    {
      auto it = mTextFormats.find( name );
      if ( it == mTextFormats.end() )
        return false;

      mTextFormats.erase( it );
      break;
    }

    case QgsStyle::LabelSettingsEntity:
    {
      auto it = mLabelSettings.find( name );
      if ( it == mLabelSettings.end() )
        return false;

      mLabelSettings.erase( it );
      break;
    }

    case QgsStyle::LegendPatchShapeEntity:
    {
      auto it = mLegendPatchShapes.find( name );
      if ( it == mLegendPatchShapes.end() )
        return false;

      mLegendPatchShapes.erase( it );
      break;
    }
  }

  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database to modify."_s );
    return false;
  }

  const int id = entityId( type, name );
  if ( !id )
  {
    QgsDebugError( "No matching entity for deleting in database: " + name );
  }

  const bool result = remove( type, id );
  if ( result )
  {
    mCachedTags[type].remove( name );
    mCachedFavorites[type].remove( name );

    switch ( type )
    {
      case SymbolEntity:
        emit symbolRemoved( name );
        break;

      case ColorrampEntity:
        emit rampRemoved( name );
        break;

      case TextFormatEntity:
        emit textFormatRemoved( name );
        break;

      case LabelSettingsEntity:
        emit labelSettingsRemoved( name );
        break;

      default:
        // these specific signals should be discouraged -- don't add them for new entity types!
        break;
    }
    emit entityRemoved( type, name );
  }
  return result;
}

bool QgsStyle::runEmptyQuery( const QString &query )
{
  if ( !mCurrentDB )
    return false;

  char *zErr = nullptr;
  int nErr = sqlite3_exec( mCurrentDB.get(), query.toUtf8().constData(), nullptr, nullptr, &zErr );

  if ( nErr != SQLITE_OK )
  {
    QgsDebugError( zErr );
    sqlite3_free( zErr );
  }

  return nErr == SQLITE_OK;
}

bool QgsStyle::addFavorite( StyleEntity type, const QString &name )
{
  QString query;

  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      QgsDebugError( u"Wrong entity value. cannot apply group"_s );
      return false;

    default:
      query = qgs_sqlite3_mprintf( u"UPDATE %1 SET favorite=1 WHERE name='%q'"_s.arg( entityTableName( type ) ).toLocal8Bit().data(), name.toUtf8().constData() );
      break;
  }

  const bool res = runEmptyQuery( query );
  if ( res )
  {
    switch ( type )
    {
      case TagEntity:
      case SmartgroupEntity:
        break;

      default:
        mCachedFavorites[type].insert( name, true );
        break;
    }
    emit favoritedChanged( type, name, true );
  }

  return res;
}

bool QgsStyle::removeFavorite( StyleEntity type, const QString &name )
{
  QString query;

  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      QgsDebugError( u"Wrong entity value. cannot apply group"_s );
      return false;

    default:
      query = qgs_sqlite3_mprintf( u"UPDATE %1 SET favorite=0 WHERE name='%q'"_s.arg( entityTableName( type ) ).toLocal8Bit().data(), name.toUtf8().constData() );
      break;
  }

  const bool res = runEmptyQuery( query );
  if ( res )
  {
    mCachedFavorites[type].insert( name, false );
    emit favoritedChanged( type, name, false );
  }

  return res;
}

QStringList QgsStyle::findSymbols( StyleEntity type, const QString &qword )
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database to search"_s );
    return QStringList();
  }

  // first find symbols with matching name
  QString item;
  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      return QStringList();

    default:
      item = entityTableName( type );
      break;
  }

  QString query = qgs_sqlite3_mprintf( "SELECT name FROM %q WHERE name LIKE '%%%q%%'", item.toUtf8().constData(), qword.toUtf8().constData() );

  sqlite3_statement_unique_ptr statement;
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );

  QSet< QString > symbols;
  while ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    symbols << statement.columnAsText( 0 );
  }

  // next add symbols with matching tags
  query = qgs_sqlite3_mprintf( "SELECT id FROM tag WHERE name LIKE '%%%q%%'", qword.toUtf8().constData() );
  statement = mCurrentDB.prepare( query, nErr );

  QStringList tagids;
  while ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    tagids << statement.columnAsText( 0 );
  }

  QString dummy = tagids.join( ", "_L1 );
  query = qgs_sqlite3_mprintf( u"SELECT %1 FROM %2 WHERE tag_id IN (%q)"_s.arg( tagmapEntityIdFieldName( type ), tagmapTableName( type ) ).toLocal8Bit().data(), dummy.toUtf8().constData() );

  statement = mCurrentDB.prepare( query, nErr );

  QStringList symbolids;
  while ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    symbolids << statement.columnAsText( 0 );
  }

  dummy = symbolids.join( ", "_L1 );
  query = qgs_sqlite3_mprintf( "SELECT name FROM %q  WHERE id IN (%q)", item.toUtf8().constData(), dummy.toUtf8().constData() );
  statement = mCurrentDB.prepare( query, nErr );
  while ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    symbols << statement.columnAsText( 0 );
  }

  return QStringList( symbols.constBegin(), symbols.constEnd() );
}

bool QgsStyle::tagSymbol( StyleEntity type, const QString &symbol, const QStringList &tags )
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database to tag."_s );
    return false;
  }

  int symbolid = 0;
  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      return false;

    default:
      symbolid = entityId( type, symbol );
      break;
  }

  if ( !symbolid )
  {
    QgsDebugError( u"No such symbol for tagging in database: "_s + symbol );
    return false;
  }

  QString tag;
  const auto constTags = tags;
  for ( const QString &t : constTags )
  {
    tag = t.trimmed();
    if ( !tag.isEmpty() )
    {
      // sql: gets the id of the tag if present or insert the tag and get the id of the tag
      int tagid( tagId( tag ) );
      if ( !tagid )
      {
        tagid = addTag( tag );
      }

      // Now map the tag to the symbol if it's not already tagged
      if ( !symbolHasTag( type, symbol, tag ) )
      {
        QString query = qgs_sqlite3_mprintf( u"INSERT INTO %1 VALUES (%d,%d)"_s.arg( tagmapTableName( type ) ).toLocal8Bit().data(), tagid, symbolid );

        char *zErr = nullptr;
        int nErr;
        nErr = sqlite3_exec( mCurrentDB.get(), query.toUtf8().constData(), nullptr, nullptr, &zErr );
        if ( nErr )
        {
          QgsDebugError( zErr );
          sqlite3_free( zErr );
        }
      }
    }
  }

  clearCachedTags( type, symbol );
  emit entityTagsChanged( type, symbol, tagsOfSymbol( type, symbol ) );

  return true;
}

bool QgsStyle::detagSymbol( StyleEntity type, const QString &symbol, const QStringList &tags )
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database for detagging."_s );
    return false;
  }

  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      return false;

    default:
      break;
  }

  const int symbolid = entityId( type, symbol );
  if ( symbolid == 0 )
    return false;

  int nErr;
  QString query;
  const auto constTags = tags;
  for ( const QString &tag : constTags )
  {
    query = qgs_sqlite3_mprintf( "SELECT id FROM tag WHERE name='%q'", tag.toUtf8().constData() );

    sqlite3_statement_unique_ptr statement2;
    statement2 = mCurrentDB.prepare( query, nErr );

    int tagid = 0;
    if ( nErr == SQLITE_OK && sqlite3_step( statement2.get() ) == SQLITE_ROW )
    {
      tagid = sqlite3_column_int( statement2.get(), 0 );
    }

    if ( tagid )
    {
      // remove from the tagmap
      const QString query = qgs_sqlite3_mprintf( u"DELETE FROM %1 WHERE tag_id=%d AND %2=%d"_s.arg( tagmapTableName( type ), tagmapEntityIdFieldName( type ) ).toLocal8Bit().data(), tagid, symbolid );
      runEmptyQuery( query );
    }
  }

  clearCachedTags( type, symbol );
  emit entityTagsChanged( type, symbol, tagsOfSymbol( type, symbol ) );

  // TODO Perform tag cleanup
  // check the number of entries for a given tag in the tagmap
  // if the count is 0, then remove( TagEntity, tagid )
  return true;
}

bool QgsStyle::detagSymbol( StyleEntity type, const QString &symbol )
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database for detagging."_s );
    return false;
  }

  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      return false;

    default:
      break;
  }

  const int symbolid = entityId( type, symbol );
  if ( symbolid == 0 )
  {
    return false;
  }

  // remove all tags
  const QString query = qgs_sqlite3_mprintf( u"DELETE FROM %1 WHERE %2=%d"_s.arg( tagmapTableName( type ), tagmapEntityIdFieldName( type ) ).toLocal8Bit().data(), symbolid );
  runEmptyQuery( query );

  clearCachedTags( type, symbol );
  emit entityTagsChanged( type, symbol, QStringList() );

  // TODO Perform tag cleanup
  // check the number of entries for a given tag in the tagmap
  // if the count is 0, then remove( TagEntity, tagid )
  return true;
}

QStringList QgsStyle::tagsOfSymbol( StyleEntity type, const QString &symbol )
{
  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      return QStringList();

    default:
    {
      auto it = mCachedTags[type].constFind( symbol );
      if ( it != mCachedTags[type].constEnd() )
        return it.value();
      break;
    }
  }

  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database for getting the tags."_s );
    return QStringList();
  }

  int symbolid = entityId( type, symbol );
  if ( !symbolid )
    return QStringList();

  // get the ids of tags for the symbol
  const QString query = qgs_sqlite3_mprintf( u"SELECT tag_id FROM %1 WHERE %2=%d"_s.arg( tagmapTableName( type ), tagmapEntityIdFieldName( type ) ).toLocal8Bit().data(), symbolid );

  sqlite3_statement_unique_ptr statement;
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );

  QStringList tagList;
  while ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    QString subquery = qgs_sqlite3_mprintf( "SELECT name FROM tag WHERE id=%d", sqlite3_column_int( statement.get(), 0 ) );

    sqlite3_statement_unique_ptr statement2;
    int pErr;
    statement2 = mCurrentDB.prepare( subquery, pErr );
    if ( pErr == SQLITE_OK && sqlite3_step( statement2.get() ) == SQLITE_ROW )
    {
      tagList << statement2.columnAsText( 0 );
    }
  }

  // update cache
  mCachedTags[type].insert( symbol, tagList );

  return tagList;
}

bool QgsStyle::isFavorite( QgsStyle::StyleEntity type, const QString &name )
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database for getting the tags."_s );
    return false;
  }

  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      return false;

    default:
    {
      auto it = mCachedFavorites[type].constFind( name );
      if ( it != mCachedFavorites[type].constEnd() )
        return it.value();
      break;
    }
  }

  const QStringList names = allNames( type );
  if ( !names.contains( name ) )
    return false; // entity doesn't exist

  // for efficiency, retrieve names of all favorited symbols and store them in cache
  const QStringList favorites = symbolsOfFavorite( type );
  bool res = false;
  for ( const QString &n : names )
  {
    const bool isFav = favorites.contains( n );
    if ( n == name )
      res = isFav;

    mCachedFavorites[type].insert( n, isFav );
  }
  return res;
}

bool QgsStyle::symbolHasTag( StyleEntity type, const QString &symbol, const QString &tag )
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Sorry! Cannot open database for getting the tags."_s );
    return false;
  }

  int symbolid = 0;
  switch ( type )
  {
    case TagEntity:
    case SmartgroupEntity:
      return false;

    default:
      symbolid = entityId( type, symbol );
      break;
  }

  if ( !symbolid )
  {
    return false;
  }
  int tagid = tagId( tag );
  if ( !tagid )
  {
    return false;
  }

  // get the ids of tags for the symbol
  const QString query = qgs_sqlite3_mprintf( u"SELECT tag_id FROM %1 WHERE tag_id=%d AND %2=%d"_s.arg( tagmapTableName( type ), tagmapEntityIdFieldName( type ) ).toLocal8Bit().data(), tagid, symbolid );

  sqlite3_statement_unique_ptr statement;
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );

  return ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW );
}

QString QgsStyle::tag( int id ) const
{
  if ( !mCurrentDB )
    return QString();

  sqlite3_statement_unique_ptr statement;

  QString query = qgs_sqlite3_mprintf( "SELECT name FROM tag WHERE id=%d", id );
  int nError;
  statement = mCurrentDB.prepare( query, nError );

  QString tag;
  if ( nError == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    tag = statement.columnAsText( 0 );
  }

  return tag;
}

int QgsStyle::getId( const QString &table, const QString &name )
{
  QString lowerName( name.toLower() );
  QString query = qgs_sqlite3_mprintf( "SELECT id FROM %q WHERE LOWER(name)='%q'", table.toUtf8().constData(), lowerName.toUtf8().constData() );

  sqlite3_statement_unique_ptr statement;
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );

  int id = 0;
  if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    id = sqlite3_column_int( statement.get(), 0 );
  }
  else
  {
    // Try the name without lowercase conversion
    QString query = qgs_sqlite3_mprintf( "SELECT id FROM %q WHERE name='%q'", table.toUtf8().constData(), name.toUtf8().constData() );

    sqlite3_statement_unique_ptr statement;
    int nErr;
    statement = mCurrentDB.prepare( query, nErr );
    if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      id = sqlite3_column_int( statement.get(), 0 );
    }
  }

  return id;
}

QString QgsStyle::getName( const QString &table, int id ) const
{
  QString query = qgs_sqlite3_mprintf( "SELECT name FROM %q WHERE id='%q'", table.toUtf8().constData(), QString::number( id ).toUtf8().constData() );

  sqlite3_statement_unique_ptr statement;
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );

  QString name;
  if ( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    name = statement.columnAsText( 0 );
  }

  return name;
}

int QgsStyle::symbolId( const QString &name )
{
  return getId( u"symbol"_s, name );
}

int QgsStyle::entityId( QgsStyle::StyleEntity type, const QString &name )
{
  return getId( entityTableName( type ), name );
}

int QgsStyle::colorrampId( const QString &name )
{
  return getId( u"colorramp"_s, name );
}

QgsTextFormat QgsStyle::textFormat( const QString &name ) const
{
  return mTextFormats.value( name );
}

int QgsStyle::textFormatCount() const
{
  return static_cast< int >( mTextFormats.count() );
}

QStringList QgsStyle::textFormatNames() const
{
  return mTextFormats.keys();
}

int QgsStyle::textFormatId( const QString &name )
{
  return getId( u"textformat"_s, name );
}

QgsPalLayerSettings QgsStyle::labelSettings( const QString &name ) const
{
  return mLabelSettings.value( name );
}

QgsLegendPatchShape QgsStyle::legendPatchShape( const QString &name ) const
{
  return mLegendPatchShapes.value( name );
}

int QgsStyle::legendPatchShapesCount() const
{
  return static_cast< int >( mLegendPatchShapes.count() );
}

Qgis::SymbolType QgsStyle::legendPatchShapeSymbolType( const QString &name ) const
{
  auto it = mLegendPatchShapes.constFind( name );
  if ( it == mLegendPatchShapes.constEnd() )
    return Qgis::SymbolType::Hybrid;

  return it.value().symbolType();
}

std::unique_ptr<QgsAbstract3DSymbol> QgsStyle::symbol3D( const QString &name ) const
{
  auto it = m3dSymbols.constFind( name );
  if ( it != m3dSymbols.constEnd() )
    return std::unique_ptr<QgsAbstract3DSymbol>( it.value()->clone() );
  return nullptr;
}

int QgsStyle::symbol3DCount() const
{
  return static_cast< int >( m3dSymbols.count() );
}

QList<Qgis::GeometryType> QgsStyle::symbol3DCompatibleGeometryTypes( const QString &name ) const
{
  auto it = m3dSymbols.constFind( name );
  if ( it == m3dSymbols.constEnd() )
    return QList<Qgis::GeometryType>();

  return it.value()->compatibleGeometryTypes();
}

Qgis::GeometryType QgsStyle::labelSettingsLayerType( const QString &name ) const
{
  auto it = mLabelSettings.constFind( name );
  if ( it == mLabelSettings.constEnd() )
    return Qgis::GeometryType::Unknown;

  return it.value().layerType;
}

int QgsStyle::labelSettingsCount() const
{
  return static_cast< int >( mLabelSettings.count() );
}

QStringList QgsStyle::labelSettingsNames() const
{
  return mLabelSettings.keys();
}

int QgsStyle::labelSettingsId( const QString &name )
{
  return getId( u"labelsettings"_s, name );
}

QStringList QgsStyle::legendPatchShapeNames() const
{
  return mLegendPatchShapes.keys();
}

const QgsSymbol *QgsStyle::previewSymbolForPatchShape( const QgsLegendPatchShape &shape ) const
{
  switch ( shape.symbolType() )
  {
    case Qgis::SymbolType::Marker:
      return mPatchMarkerSymbol.get();

    case Qgis::SymbolType::Line:
      return mPatchLineSymbol.get();

    case Qgis::SymbolType::Fill:
      return mPatchFillSymbol.get();

    case Qgis::SymbolType::Hybrid:
      break;
  }
  return nullptr;
}

int QgsStyle::tagId( const QString &name )
{
  return getId( u"tag"_s, name );
}

int QgsStyle::smartgroupId( const QString &name )
{
  return getId( u"smartgroup"_s, name );
}

QStringList QgsStyle::allNames( QgsStyle::StyleEntity type ) const
{
  switch ( type )
  {
    case SymbolEntity:
      return symbolNames();

    case ColorrampEntity:
      return colorRampNames();

    case TextFormatEntity:
      return textFormatNames();

    case LabelSettingsEntity:
      return labelSettingsNames();

    case LegendPatchShapeEntity:
      return legendPatchShapeNames();

    case Symbol3DEntity:
      return symbol3DNames();

    case MaterialSettingsEntity:
      return materialSettingsNames();

    case TagEntity:
      return tags();

    case SmartgroupEntity:
      return smartgroupNames();
  }
  return QStringList();
}

int QgsStyle::addSmartgroup( const QString &name, const QString &op, const QgsSmartConditionMap &conditions )
{
  return addSmartgroup( name, op, conditions.values( u"tag"_s ), conditions.values( u"!tag"_s ), conditions.values( u"name"_s ), conditions.values( u"!name"_s ) );
}

int QgsStyle::addSmartgroup( const QString &name, const QString &op, const QStringList &matchTag, const QStringList &noMatchTag, const QStringList &matchName, const QStringList &noMatchName )
{
  QDomDocument doc( u"dummy"_s );
  QDomElement smartEl = doc.createElement( u"smartgroup"_s );
  smartEl.setAttribute( u"name"_s, name );
  smartEl.setAttribute( u"operator"_s, op );

  auto addCondition = [&doc, &smartEl]( const QString &constraint, const QStringList &parameters ) {
    for ( const QString &param : parameters )
    {
      QDomElement condEl = doc.createElement( u"condition"_s );
      condEl.setAttribute( u"constraint"_s, constraint );
      condEl.setAttribute( u"param"_s, param );
      smartEl.appendChild( condEl );
    }
  };
  addCondition( u"tag"_s, matchTag );
  addCondition( u"!tag"_s, noMatchTag );
  addCondition( u"name"_s, matchName );
  addCondition( u"!name"_s, noMatchName );

  QByteArray xmlArray;
  QTextStream stream( &xmlArray );
  smartEl.save( stream, 4 );
  QString query = qgs_sqlite3_mprintf( "INSERT INTO smartgroup VALUES (NULL, '%q', '%q')", name.toUtf8().constData(), xmlArray.constData() );

  if ( runEmptyQuery( query ) )
  {
    QgsSettingsRegistryCore::settingsSymbolsListGroupsIndex->setValue( 0 );

    emit groupsModified();
    return static_cast< int >( sqlite3_last_insert_rowid( mCurrentDB.get() ) );
  }
  else
  {
    QgsDebugError( u"Couldn't add the smart group into the database!"_s );
    return 0;
  }
}

QgsSymbolGroupMap QgsStyle::smartgroupsListMap()
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Cannot open database for listing groups"_s );
    return QgsSymbolGroupMap();
  }

  QString query = qgs_sqlite3_mprintf( "SELECT * FROM smartgroup" );

  // Now run the query and retrieve the group names
  sqlite3_statement_unique_ptr statement;
  int nError;
  statement = mCurrentDB.prepare( query, nError );

  QgsSymbolGroupMap groupNames;
  while ( nError == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    QString group = statement.columnAsText( static_cast< int >( SmartGroupTableColumn::Name ) );
    groupNames.insert( sqlite3_column_int( statement.get(), static_cast< int >( SmartGroupTableColumn::Id ) ), group );
  }

  return groupNames;
}

QStringList QgsStyle::smartgroupNames() const
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Cannot open database for listing groups"_s );
    return QStringList();
  }

  QString query = qgs_sqlite3_mprintf( "SELECT name FROM smartgroup" );

  // Now run the query and retrieve the group names
  sqlite3_statement_unique_ptr statement;
  int nError;
  statement = mCurrentDB.prepare( query, nError );

  QStringList groups;
  while ( nError == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    groups << statement.columnAsText( 0 );
  }

  return groups;
}

QStringList QgsStyle::symbolsOfSmartgroup( StyleEntity type, int id )
{
  QStringList symbols;

  QString query = qgs_sqlite3_mprintf( "SELECT xml FROM smartgroup WHERE id=%d", id );

  sqlite3_statement_unique_ptr statement;
  int nErr;
  statement = mCurrentDB.prepare( query, nErr );
  if ( !( nErr == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW ) )
  {
    return QStringList();
  }
  else
  {
    QDomDocument doc;
    QString xmlstr = statement.columnAsText( 0 );
    if ( !doc.setContent( xmlstr ) )
    {
      QgsDebugError( u"Cannot open smartgroup id: %1"_s.arg( id ) );
    }
    QDomElement smartEl = doc.documentElement();
    QString op = smartEl.attribute( u"operator"_s );
    QDomNodeList conditionNodes = smartEl.childNodes();

    bool firstSet = true;
    for ( int i = 0; i < conditionNodes.count(); i++ )
    {
      QDomElement condEl = conditionNodes.at( i ).toElement();
      QString constraint = condEl.attribute( u"constraint"_s );
      QString param = condEl.attribute( u"param"_s );

      QStringList resultNames;
      // perform suitable action for the given constraint
      if ( constraint == "tag"_L1 )
      {
        resultNames = symbolsWithTag( type, tagId( param ) );
      }
      else if ( constraint == "name"_L1 )
      {
        resultNames = allNames( type ).filter( param, Qt::CaseInsensitive );
      }
      else if ( constraint == "!tag"_L1 )
      {
        resultNames = allNames( type );
        const QStringList unwanted = symbolsWithTag( type, tagId( param ) );
        for ( const QString &name : unwanted )
        {
          resultNames.removeAll( name );
        }
      }
      else if ( constraint == "!name"_L1 )
      {
        const QStringList all = allNames( type );
        for ( const QString &str : all )
        {
          if ( !str.contains( param, Qt::CaseInsensitive ) )
            resultNames << str;
        }
      }

      // not apply the operator
      if ( firstSet )
      {
        symbols = resultNames;
        firstSet = false;
      }
      else
      {
        if ( op == "OR"_L1 )
        {
          symbols << resultNames;
        }
        else if ( op == "AND"_L1 )
        {
          QStringList dummy = symbols;
          symbols.clear();
          for ( const QString &result : std::as_const( resultNames ) )
          {
            if ( dummy.contains( result ) )
              symbols << result;
          }
        }
      }
    } // DOM loop ends here
  }

  // return sorted, unique list
  const QSet< QString > uniqueSet( symbols.constBegin(), symbols.constEnd() );
  QStringList unique( uniqueSet.begin(), uniqueSet.end() );
  std::sort( unique.begin(), unique.end() );
  return unique;
}

QgsSmartConditionMap QgsStyle::smartgroup( int id )
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Cannot open database for listing groups"_s );
    return QgsSmartConditionMap();
  }

  QgsSmartConditionMap condition;

  QString query = qgs_sqlite3_mprintf( "SELECT xml FROM smartgroup WHERE id=%d", id );

  sqlite3_statement_unique_ptr statement;
  int nError;
  statement = mCurrentDB.prepare( query, nError );
  if ( nError == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    QDomDocument doc;
    QString xmlstr = statement.columnAsText( 0 );
    if ( !doc.setContent( xmlstr ) )
    {
      QgsDebugError( u"Cannot open smartgroup id: %1"_s.arg( id ) );
    }

    QDomElement smartEl = doc.documentElement();
    QDomNodeList conditionNodes = smartEl.childNodes();

    for ( int i = 0; i < conditionNodes.count(); i++ )
    {
      QDomElement condEl = conditionNodes.at( i ).toElement();
      QString constraint = condEl.attribute( u"constraint"_s );
      QString param = condEl.attribute( u"param"_s );

      condition.insert( constraint, param );
    }
  }

  return condition;
}

QString QgsStyle::smartgroupOperator( int id )
{
  if ( !mCurrentDB )
  {
    QgsDebugError( u"Cannot open database for listing groups"_s );
    return QString();
  }

  QString op;

  QString query = qgs_sqlite3_mprintf( "SELECT xml FROM smartgroup WHERE id=%d", id );

  int nError;
  sqlite3_statement_unique_ptr statement;
  statement = mCurrentDB.prepare( query, nError );
  if ( nError == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
  {
    QDomDocument doc;
    QString xmlstr = statement.columnAsText( 0 );
    if ( !doc.setContent( xmlstr ) )
    {
      QgsDebugError( u"Cannot open smartgroup id: %1"_s.arg( id ) );
    }
    QDomElement smartEl = doc.documentElement();
    op = smartEl.attribute( u"operator"_s );
  }

  return op;
}

bool QgsStyle::exportXml( const QString &filename )
{
  if ( filename.isEmpty() )
  {
    QgsDebugError( u"Invalid filename for style export."_s );
    return false;
  }

  QDomDocument doc( u"qgis_style"_s );
  QDomElement root = doc.createElement( u"qgis_style"_s );
  root.setAttribute( u"version"_s, QStringLiteral( STYLE_CURRENT_VERSION ) );
  doc.appendChild( root );

  const QStringList favoriteSymbols = symbolsOfFavorite( SymbolEntity );
  const QStringList favoriteColorramps = symbolsOfFavorite( ColorrampEntity );
  const QStringList favoriteTextFormats = symbolsOfFavorite( TextFormatEntity );
  const QStringList favoriteLegendShapes = symbolsOfFavorite( LegendPatchShapeEntity );
  const QStringList favorite3DSymbols = symbolsOfFavorite( Symbol3DEntity );
  const QStringList favoriteMaterialSettings = symbolsOfFavorite( MaterialSettingsEntity );

  // save symbols and attach tags
  QDomElement symbolsElem = QgsSymbolLayerUtils::saveSymbols( mSymbols, u"symbols"_s, doc, QgsReadWriteContext() );
  QDomNodeList symbolsList = symbolsElem.elementsByTagName( u"symbol"_s );
  int nbSymbols = symbolsList.count();
  for ( int i = 0; i < nbSymbols; ++i )
  {
    QDomElement symbol = symbolsList.at( i ).toElement();
    QString name = symbol.attribute( u"name"_s );
    QStringList tags = tagsOfSymbol( SymbolEntity, name );
    if ( tags.count() > 0 )
    {
      symbol.setAttribute( u"tags"_s, tags.join( ',' ) );
    }
    if ( favoriteSymbols.contains( name ) )
    {
      symbol.setAttribute( u"favorite"_s, u"1"_s );
    }
  }

  // save color ramps
  QDomElement rampsElem = doc.createElement( u"colorramps"_s );
  for ( QMap<QString, QgsColorRamp *>::const_iterator itr = mColorRamps.constBegin(); itr != mColorRamps.constEnd(); ++itr )
  {
    QDomElement rampEl = QgsSymbolLayerUtils::saveColorRamp( itr.key(), itr.value(), doc );
    QStringList tags = tagsOfSymbol( ColorrampEntity, itr.key() );
    if ( tags.count() > 0 )
    {
      rampEl.setAttribute( u"tags"_s, tags.join( ',' ) );
    }
    if ( favoriteColorramps.contains( itr.key() ) )
    {
      rampEl.setAttribute( u"favorite"_s, u"1"_s );
    }
    rampsElem.appendChild( rampEl );
  }

  // save text formats
  QDomElement textFormatsElem = doc.createElement( u"textformats"_s );
  for ( auto it = mTextFormats.constBegin(); it != mTextFormats.constEnd(); ++it )
  {
    QDomElement textFormatEl = doc.createElement( u"textformat"_s );
    textFormatEl.setAttribute( u"name"_s, it.key() );
    QDomElement textStyleEl = it.value().writeXml( doc, QgsReadWriteContext() );
    textFormatEl.appendChild( textStyleEl );
    QStringList tags = tagsOfSymbol( TextFormatEntity, it.key() );
    if ( tags.count() > 0 )
    {
      textFormatEl.setAttribute( u"tags"_s, tags.join( ',' ) );
    }
    if ( favoriteTextFormats.contains( it.key() ) )
    {
      textFormatEl.setAttribute( u"favorite"_s, u"1"_s );
    }
    textFormatsElem.appendChild( textFormatEl );
  }

  // save label settings
  QDomElement labelSettingsElem = doc.createElement( u"labelsettings"_s );
  for ( auto it = mLabelSettings.constBegin(); it != mLabelSettings.constEnd(); ++it )
  {
    QDomElement labelSettingsEl = doc.createElement( u"labelsetting"_s );
    labelSettingsEl.setAttribute( u"name"_s, it.key() );
    QDomElement defEl = it.value().writeXml( doc, QgsReadWriteContext() );
    labelSettingsEl.appendChild( defEl );
    QStringList tags = tagsOfSymbol( LabelSettingsEntity, it.key() );
    if ( tags.count() > 0 )
    {
      labelSettingsEl.setAttribute( u"tags"_s, tags.join( ',' ) );
    }
    if ( favoriteTextFormats.contains( it.key() ) )
    {
      labelSettingsEl.setAttribute( u"favorite"_s, u"1"_s );
    }
    labelSettingsElem.appendChild( labelSettingsEl );
  }

  // save legend patch shapes
  QDomElement legendPatchShapesElem = doc.createElement( u"legendpatchshapes"_s );
  for ( auto it = mLegendPatchShapes.constBegin(); it != mLegendPatchShapes.constEnd(); ++it )
  {
    QDomElement legendPatchShapeEl = doc.createElement( u"legendpatchshape"_s );
    legendPatchShapeEl.setAttribute( u"name"_s, it.key() );
    QDomElement defEl = doc.createElement( u"definition"_s );
    it.value().writeXml( defEl, doc, QgsReadWriteContext() );
    legendPatchShapeEl.appendChild( defEl );
    QStringList tags = tagsOfSymbol( LegendPatchShapeEntity, it.key() );
    if ( tags.count() > 0 )
    {
      legendPatchShapeEl.setAttribute( u"tags"_s, tags.join( ',' ) );
    }
    if ( favoriteLegendShapes.contains( it.key() ) )
    {
      legendPatchShapeEl.setAttribute( u"favorite"_s, u"1"_s );
    }
    legendPatchShapesElem.appendChild( legendPatchShapeEl );
  }

  // save 3D symbols and attach tags
  QDomElement symbols3DElem = doc.createElement( u"symbols3d"_s );
  for ( auto it = m3dSymbols.constBegin(); it != m3dSymbols.constEnd(); ++it )
  {
    QDomElement symbolEl = doc.createElement( u"symbol3d"_s );
    symbolEl.setAttribute( u"name"_s, it.key() );
    QDomElement defEl = doc.createElement( u"definition"_s );
    defEl.setAttribute( u"type"_s, it.value()->type() );
    it.value()->writeXml( defEl, QgsReadWriteContext() );
    symbolEl.appendChild( defEl );
    QStringList tags = tagsOfSymbol( Symbol3DEntity, it.key() );
    if ( tags.count() > 0 )
    {
      symbolEl.setAttribute( u"tags"_s, tags.join( ',' ) );
    }
    if ( favorite3DSymbols.contains( it.key() ) )
    {
      symbolEl.setAttribute( u"favorite"_s, u"1"_s );
    }
    symbols3DElem.appendChild( symbolEl );
  }

  // save material settings and attach tags
  QDomElement materialSettingsElem = doc.createElement( u"materialsettings"_s );
  for ( auto it = mMaterialSettings.constBegin(); it != mMaterialSettings.constEnd(); ++it )
  {
    QDomElement materialSettingEl = doc.createElement( u"material"_s );
    materialSettingEl.setAttribute( u"name"_s, it.key() );
    QDomElement defEl = doc.createElement( u"definition"_s );
    it.value()->writeXml( defEl, QgsReadWriteContext() );
    materialSettingEl.appendChild( defEl );
    QStringList tags = tagsOfSymbol( MaterialSettingsEntity, it.key() );
    if ( tags.count() > 0 )
    {
      materialSettingEl.setAttribute( u"tags"_s, tags.join( ',' ) );
    }
    if ( favoriteMaterialSettings.contains( it.key() ) )
    {
      materialSettingEl.setAttribute( u"favorite"_s, u"1"_s );
    }
    materialSettingsElem.appendChild( materialSettingEl );
  }
  root.appendChild( symbolsElem );
  root.appendChild( rampsElem );
  root.appendChild( textFormatsElem );
  root.appendChild( labelSettingsElem );
  root.appendChild( legendPatchShapesElem );
  root.appendChild( symbols3DElem );
  root.appendChild( materialSettingsElem );

  // save
  QFile f( filename );
  if ( !f.open( QFile::WriteOnly | QIODevice::Truncate ) )
  {
    mErrorString = "Couldn't open file for writing: " + filename;
    return false;
  }

  QTextStream ts( &f );
  doc.save( ts, 2 );
  f.close();

  return true;
}

bool QgsStyle::importXml( const QString &filename )
{
  return importXml( filename, -1 );
}

bool QgsStyle::importXml( const QString &filename, int sinceVersion )
{
  mErrorString = QString();
  QDomDocument doc( u"style"_s );
  QFile f( filename );
  if ( !f.open( QFile::ReadOnly ) )
  {
    mErrorString = u"Unable to open the specified file"_s;
    QgsDebugError( u"Error opening the style XML file."_s );
    return false;
  }

  if ( !doc.setContent( &f ) )
  {
    mErrorString = u"Unable to understand the style file: %1"_s.arg( filename );
    QgsDebugError( u"XML Parsing error"_s );
    f.close();
    return false;
  }
  f.close();

  QDomElement docEl = doc.documentElement();
  if ( docEl.tagName() != "qgis_style"_L1 )
  {
    mErrorString = "Incorrect root tag in style: " + docEl.tagName();
    return false;
  }

  const QString version = docEl.attribute( u"version"_s );
  if ( version != QLatin1String( STYLE_CURRENT_VERSION ) && version != "0"_L1 && version != "1"_L1 )
  {
    mErrorString = "Unknown style file version: " + version;
    return false;
  }

  QgsSymbolMap symbols;

  QDomElement symbolsElement = docEl.firstChildElement( u"symbols"_s );
  QDomElement e = symbolsElement.firstChildElement();

  // gain speed by re-grouping the INSERT statements in a transaction
  QString query = qgs_sqlite3_mprintf( "BEGIN TRANSACTION;" );
  runEmptyQuery( query );

  if ( version == QLatin1String( STYLE_CURRENT_VERSION ) || version == "1"_L1 )
  {
    // For the new style, load symbols individually
    for ( ; !e.isNull(); e = e.nextSiblingElement() )
    {
      const int entityAddedVersion = e.attribute( u"addedVersion"_s ).toInt();
      if ( entityAddedVersion != 0 && sinceVersion != -1 && entityAddedVersion <= sinceVersion )
      {
        // skip the symbol, should already be present
        continue;
      }

      if ( e.tagName() == "symbol"_L1 )
      {
        QString name = e.attribute( u"name"_s );
        QStringList tags;
        if ( e.hasAttribute( u"tags"_s ) )
        {
          tags = e.attribute( u"tags"_s ).split( ',' );
        }
        bool favorite = false;
        if ( e.hasAttribute( u"favorite"_s ) && e.attribute( u"favorite"_s ) == "1"_L1 )
        {
          favorite = true;
        }

        std::unique_ptr< QgsSymbol > symbol = QgsSymbolLayerUtils::loadSymbol( e, QgsReadWriteContext() );
        if ( symbol )
        {
          QgsSymbol *symbolPtr = symbol.get();
          addSymbol( name, symbol.release() );
          if ( mCurrentDB )
          {
            saveSymbol( name, symbolPtr, favorite, tags );
          }
        }
      }
      else
      {
        QgsDebugError( "unknown tag: " + e.tagName() );
      }
    }
  }
  else
  {
    // for the old version, use the utility function to solve @symbol@layer subsymbols
    symbols = QgsSymbolLayerUtils::loadSymbols( symbolsElement, QgsReadWriteContext() );

    // save the symbols with proper name
    for ( QMap<QString, QgsSymbol *>::iterator it = symbols.begin(); it != symbols.end(); ++it )
    {
      addSymbol( it.key(), it.value() );
    }
  }

  // load color ramps
  QDomElement rampsElement = docEl.firstChildElement( u"colorramps"_s );
  e = rampsElement.firstChildElement();
  for ( ; !e.isNull(); e = e.nextSiblingElement() )
  {
    const int entityAddedVersion = e.attribute( u"addedVersion"_s ).toInt();
    if ( entityAddedVersion != 0 && sinceVersion != -1 && entityAddedVersion <= sinceVersion )
    {
      // skip the ramp, should already be present
      continue;
    }

    if ( e.tagName() == "colorramp"_L1 )
    {
      QString name = e.attribute( u"name"_s );
      QStringList tags;
      if ( e.hasAttribute( u"tags"_s ) )
      {
        tags = e.attribute( u"tags"_s ).split( ',' );
      }
      bool favorite = false;
      if ( e.hasAttribute( u"favorite"_s ) && e.attribute( u"favorite"_s ) == "1"_L1 )
      {
        favorite = true;
      }

      std::unique_ptr< QgsColorRamp > ramp = QgsSymbolLayerUtils::loadColorRamp( e );
      if ( ramp )
      {
        QgsColorRamp *rampPtr = ramp.get();
        addColorRamp( name, ramp.release() );
        if ( mCurrentDB )
        {
          saveColorRamp( name, rampPtr, favorite, tags );
        }
      }
    }
    else
    {
      QgsDebugError( "unknown tag: " + e.tagName() );
    }
  }

  // load text formats

  // this is ONLY safe to do if we have a QGuiApplication-- it requires QFontDatabase, which is not available otherwise!
  if ( qobject_cast< QGuiApplication * >( QCoreApplication::instance() ) )
  {
    if ( version == STYLE_CURRENT_VERSION )
    {
      const QDomElement textFormatElement = docEl.firstChildElement( u"textformats"_s );
      e = textFormatElement.firstChildElement();
      for ( ; !e.isNull(); e = e.nextSiblingElement() )
      {
        const int entityAddedVersion = e.attribute( u"addedVersion"_s ).toInt();
        if ( entityAddedVersion != 0 && sinceVersion != -1 && entityAddedVersion <= sinceVersion )
        {
          // skip the format, should already be present
          continue;
        }

        if ( e.tagName() == "textformat"_L1 )
        {
          QString name = e.attribute( u"name"_s );
          QStringList tags;
          if ( e.hasAttribute( u"tags"_s ) )
          {
            tags = e.attribute( u"tags"_s ).split( ',' );
          }
          bool favorite = false;
          if ( e.hasAttribute( u"favorite"_s ) && e.attribute( u"favorite"_s ) == "1"_L1 )
          {
            favorite = true;
          }

          QgsTextFormat format;
          const QDomElement styleElem = e.firstChildElement();
          format.readXml( styleElem, QgsReadWriteContext() );
          addTextFormat( name, format );
          if ( mCurrentDB )
          {
            saveTextFormat( name, format, favorite, tags );
          }
        }
        else
        {
          QgsDebugError( "unknown tag: " + e.tagName() );
        }
      }
    }

    // load label settings
    if ( version == STYLE_CURRENT_VERSION )
    {
      const QDomElement labelSettingsElement = docEl.firstChildElement( u"labelsettings"_s );
      e = labelSettingsElement.firstChildElement();
      for ( ; !e.isNull(); e = e.nextSiblingElement() )
      {
        const int entityAddedVersion = e.attribute( u"addedVersion"_s ).toInt();
        if ( entityAddedVersion != 0 && sinceVersion != -1 && entityAddedVersion <= sinceVersion )
        {
          // skip the settings, should already be present
          continue;
        }

        if ( e.tagName() == "labelsetting"_L1 )
        {
          QString name = e.attribute( u"name"_s );
          QStringList tags;
          if ( e.hasAttribute( u"tags"_s ) )
          {
            tags = e.attribute( u"tags"_s ).split( ',' );
          }
          bool favorite = false;
          if ( e.hasAttribute( u"favorite"_s ) && e.attribute( u"favorite"_s ) == "1"_L1 )
          {
            favorite = true;
          }

          QgsPalLayerSettings settings;
          const QDomElement styleElem = e.firstChildElement();
          settings.readXml( styleElem, QgsReadWriteContext() );
          addLabelSettings( name, settings );
          if ( mCurrentDB )
          {
            saveLabelSettings( name, settings, favorite, tags );
          }
        }
        else
        {
          QgsDebugError( "unknown tag: " + e.tagName() );
        }
      }
    }
  }

  // load legend patch shapes
  if ( version == STYLE_CURRENT_VERSION )
  {
    const QDomElement legendPatchShapesElement = docEl.firstChildElement( u"legendpatchshapes"_s );
    e = legendPatchShapesElement.firstChildElement();
    for ( ; !e.isNull(); e = e.nextSiblingElement() )
    {
      const int entityAddedVersion = e.attribute( u"addedVersion"_s ).toInt();
      if ( entityAddedVersion != 0 && sinceVersion != -1 && entityAddedVersion <= sinceVersion )
      {
        // skip the shape, should already be present
        continue;
      }

      if ( e.tagName() == "legendpatchshape"_L1 )
      {
        QString name = e.attribute( u"name"_s );
        QStringList tags;
        if ( e.hasAttribute( u"tags"_s ) )
        {
          tags = e.attribute( u"tags"_s ).split( ',' );
        }
        bool favorite = false;
        if ( e.hasAttribute( u"favorite"_s ) && e.attribute( u"favorite"_s ) == "1"_L1 )
        {
          favorite = true;
        }

        QgsLegendPatchShape shape;
        const QDomElement shapeElem = e.firstChildElement();
        shape.readXml( shapeElem, QgsReadWriteContext() );
        addLegendPatchShape( name, shape );
        if ( mCurrentDB )
        {
          saveLegendPatchShape( name, shape, favorite, tags );
        }
      }
      else
      {
        QgsDebugError( "unknown tag: " + e.tagName() );
      }
    }
  }

  // load 3d symbols
  if ( version == STYLE_CURRENT_VERSION )
  {
    const QDomElement symbols3DElement = docEl.firstChildElement( u"symbols3d"_s );
    e = symbols3DElement.firstChildElement();
    for ( ; !e.isNull(); e = e.nextSiblingElement() )
    {
      const int entityAddedVersion = e.attribute( u"addedVersion"_s ).toInt();
      if ( entityAddedVersion != 0 && sinceVersion != -1 && entityAddedVersion <= sinceVersion )
      {
        // skip the symbol, should already be present
        continue;
      }

      if ( e.tagName() == "symbol3d"_L1 )
      {
        QString name = e.attribute( u"name"_s );
        QStringList tags;
        if ( e.hasAttribute( u"tags"_s ) )
        {
          tags = e.attribute( u"tags"_s ).split( ',' );
        }
        bool favorite = false;
        if ( e.hasAttribute( u"favorite"_s ) && e.attribute( u"favorite"_s ) == "1"_L1 )
        {
          favorite = true;
        }

        const QDomElement symbolElem = e.firstChildElement();
        const QString type = symbolElem.attribute( u"type"_s );
        std::unique_ptr< QgsAbstract3DSymbol > sym( QgsApplication::symbol3DRegistry()->createSymbol( type ) );
        if ( sym )
        {
          sym->readXml( symbolElem, QgsReadWriteContext() );
          QgsAbstract3DSymbol *newSym = sym.get();
          addSymbol3D( name, sym.release() );
          if ( mCurrentDB )
          {
            saveSymbol3D( name, newSym, favorite, tags );
          }
        }
      }
      else
      {
        QgsDebugError( "unknown tag: " + e.tagName() );
      }
    }
  }

  // load material settings
  if ( version == STYLE_CURRENT_VERSION )
  {
    const QDomElement materialSettingsElement = docEl.firstChildElement( u"materialsettings"_s );
    e = materialSettingsElement.firstChildElement();
    for ( ; !e.isNull(); e = e.nextSiblingElement() )
    {
      const int entityAddedVersion = e.attribute( u"addedVersion"_s ).toInt();
      if ( entityAddedVersion != 0 && sinceVersion != -1 && entityAddedVersion <= sinceVersion )
      {
        // skip the symbol, should already be present
        continue;
      }

      if ( e.tagName() == "material"_L1 )
      {
        QString name = e.attribute( u"name"_s );
        QStringList tags;
        if ( e.hasAttribute( u"tags"_s ) )
        {
          tags = e.attribute( u"tags"_s ).split( ',' );
        }
        bool favorite = false;
        if ( e.hasAttribute( u"favorite"_s ) && e.attribute( u"favorite"_s ) == "1"_L1 )
        {
          favorite = true;
        }

        const QDomElement materialElem = e.firstChildElement();
        const QString type = materialElem.attribute( u"type"_s );
        std::unique_ptr< QgsAbstractMaterialSettings > settings( QgsApplication::materialRegistry()->createMaterialSettings( type ) );
        if ( settings )
        {
          settings->readXml( materialElem, QgsReadWriteContext() );
          QgsAbstractMaterialSettings *newMaterial = settings.get();
          addMaterialSettings( name, settings.release() );
          if ( mCurrentDB )
          {
            saveMaterialSettings( name, newMaterial, favorite, tags );
          }
        }
      }
      else
      {
        QgsDebugError( "unknown tag: " + e.tagName() );
      }
    }
  }

  query = qgs_sqlite3_mprintf( "COMMIT TRANSACTION;" );
  runEmptyQuery( query );

  return true;
}

bool QgsStyle::isXmlStyleFile( const QString &path )
{
  QFileInfo fileInfo( path );

  if ( fileInfo.suffix().compare( "xml"_L1, Qt::CaseInsensitive ) != 0 )
    return false;

  // sniff the first line of the file to see if it's a style file
  if ( !QFile::exists( path ) )
    return false;

  QFile inputFile( path );
  if ( !inputFile.open( QIODevice::ReadOnly ) )
    return false;

  QTextStream stream( &inputFile );
  const QString line = stream.readLine();
  return line == "<!DOCTYPE qgis_style>"_L1;
}

void QgsStyle::triggerIconRebuild()
{
  emit rebuildIconPreviews();
}

bool QgsStyle::isReadOnly() const
{
  return mReadOnly;
}

void QgsStyle::setReadOnly( bool readOnly )
{
  mReadOnly = readOnly;
}

bool QgsStyle::updateSymbol( StyleEntity type, const QString &name )
{
  QDomDocument doc( u"dummy"_s );
  QDomElement symEl;
  QByteArray xmlArray;
  QTextStream stream( &xmlArray );

  QString query;

  switch ( type )
  {
    case SymbolEntity:
    {
      // check if it is an existing symbol
      auto it = mSymbols.constFind( name );
      if ( it == mSymbols.constEnd() || !it.value() )
      {
        QgsDebugError( u"Update request received for unavailable symbol"_s );
        return false;
      }

      symEl = QgsSymbolLayerUtils::saveSymbol( name, it.value(), doc, QgsReadWriteContext() );
      if ( symEl.isNull() )
      {
        QgsDebugError( u"Couldn't convert symbol to valid XML!"_s );
        return false;
      }
      symEl.save( stream, 4 );
      query = qgs_sqlite3_mprintf( "UPDATE symbol SET xml='%q' WHERE name='%q';", xmlArray.constData(), name.toUtf8().constData() );
      break;
    }

    case Symbol3DEntity:
    {
      // check if it is an existing symbol
      auto it = m3dSymbols.constFind( name );
      if ( it == m3dSymbols.constEnd() || !it.value() )
      {
        QgsDebugError( u"Update request received for unavailable symbol"_s );
        return false;
      }

      symEl = doc.createElement( u"symbol"_s );
      symEl.setAttribute( u"type"_s, it.value()->type() );
      it.value()->writeXml( symEl, QgsReadWriteContext() );
      if ( symEl.isNull() )
      {
        QgsDebugError( u"Couldn't convert symbol to valid XML!"_s );
        return false;
      }
      symEl.save( stream, 4 );
      query = qgs_sqlite3_mprintf( "UPDATE symbol3d SET xml='%q' WHERE name='%q';", xmlArray.constData(), name.toUtf8().constData() );
      break;
    }

    case MaterialSettingsEntity:
    {
      // check if it is an existing symbol
      auto it = mMaterialSettings.constFind( name );
      if ( it == mMaterialSettings.constEnd() || !it.value() )
      {
        QgsDebugError( u"Update request received for unavailable material"_s );
        return false;
      }

      symEl = doc.createElement( u"material"_s );
      it.value()->writeXml( symEl, QgsReadWriteContext() );
      if ( symEl.isNull() )
      {
        QgsDebugError( u"Couldn't convert material settings to valid XML!"_s );
        return false;
      }
      symEl.save( stream, 4 );
      query = qgs_sqlite3_mprintf( "UPDATE materialsettings SET xml='%q' WHERE name='%q';", xmlArray.constData(), name.toUtf8().constData() );
      break;
    }

    case ColorrampEntity:
    {
      auto it = mColorRamps.constFind( name );
      if ( it == mColorRamps.constEnd() || !it.value() )
      {
        QgsDebugError( u"Update requested for unavailable color ramp."_s );
        return false;
      }

      symEl = QgsSymbolLayerUtils::saveColorRamp( name, it.value(), doc );
      if ( symEl.isNull() )
      {
        QgsDebugError( u"Couldn't convert color ramp to valid XML!"_s );
        return false;
      }
      symEl.save( stream, 4 );
      query = qgs_sqlite3_mprintf( "UPDATE colorramp SET xml='%q' WHERE name='%q';", xmlArray.constData(), name.toUtf8().constData() );
      break;
    }

    case TextFormatEntity:
    {
      auto it = mTextFormats.constFind( name );
      if ( it == mTextFormats.constEnd() )
      {
        QgsDebugError( u"Update requested for unavailable text format."_s );
        return false;
      }

      symEl = it.value().writeXml( doc, QgsReadWriteContext() );
      if ( symEl.isNull() )
      {
        QgsDebugError( u"Couldn't convert text format to valid XML!"_s );
        return false;
      }
      symEl.save( stream, 4 );
      query = qgs_sqlite3_mprintf( "UPDATE textformat SET xml='%q' WHERE name='%q';", xmlArray.constData(), name.toUtf8().constData() );
      break;
    }

    case LabelSettingsEntity:
    {
      auto it = mLabelSettings.constFind( name );
      if ( it == mLabelSettings.constEnd() )
      {
        QgsDebugError( u"Update requested for unavailable label settings."_s );
        return false;
      }

      symEl = it.value().writeXml( doc, QgsReadWriteContext() );
      if ( symEl.isNull() )
      {
        QgsDebugError( u"Couldn't convert label settings to valid XML!"_s );
        return false;
      }
      symEl.save( stream, 4 );
      query = qgs_sqlite3_mprintf( "UPDATE labelsettings SET xml='%q' WHERE name='%q';", xmlArray.constData(), name.toUtf8().constData() );
      break;
    }

    case LegendPatchShapeEntity:
    {
      auto it = mLegendPatchShapes.constFind( name );
      if ( it == mLegendPatchShapes.constEnd() )
      {
        QgsDebugError( u"Update requested for unavailable legend patch shape."_s );
        return false;
      }

      symEl = doc.createElement( u"shape"_s );
      it.value().writeXml( symEl, doc, QgsReadWriteContext() );
      symEl.save( stream, 4 );
      query = qgs_sqlite3_mprintf( "UPDATE legendpatchshapes SET xml='%q' WHERE name='%q';", xmlArray.constData(), name.toUtf8().constData() );
      break;
    }

    case TagEntity:
    case SmartgroupEntity:
    {
      QgsDebugError( u"Updating the unsupported StyleEntity"_s );
      return false;
    }
  }


  if ( !runEmptyQuery( query ) )
  {
    QgsDebugError( u"Couldn't update symbol into the database!"_s );
    return false;
  }
  else
  {
    switch ( type )
    {
      case SymbolEntity:
        emit symbolChanged( name );
        break;

      case ColorrampEntity:
        emit rampChanged( name );
        break;

      case TextFormatEntity:
        emit textFormatChanged( name );
        break;

      case LabelSettingsEntity:
        emit labelSettingsChanged( name );
        break;

      case LegendPatchShapeEntity:
      case TagEntity:
      case SmartgroupEntity:
      case Symbol3DEntity:
      case MaterialSettingsEntity:
        break;
    }
    emit entityChanged( type, name );
  }
  return true;
}

void QgsStyle::clearCachedTags( QgsStyle::StyleEntity type, const QString &name )
{
  mCachedTags[type].remove( name );
}

bool QgsStyle::createStyleMetadataTableIfNeeded()
{
  // make sure metadata table exists
  QString query = qgs_sqlite3_mprintf( "SELECT name FROM sqlite_master WHERE name='stylemetadata'" );
  sqlite3_statement_unique_ptr statement;
  int rc;
  statement = mCurrentDB.prepare( query, rc );

  if ( rc != SQLITE_OK || sqlite3_step( statement.get() ) != SQLITE_ROW )
  {
    // no metadata table
    query = qgs_sqlite3_mprintf(
      "CREATE TABLE stylemetadata("
      "id INTEGER PRIMARY KEY,"
      "key TEXT UNIQUE,"
      "value TEXT);"
    );
    runEmptyQuery( query );
    query = qgs_sqlite3_mprintf( "INSERT INTO stylemetadata VALUES (NULL, '%q', '%q')", "version", QString::number( Qgis::versionInt() ).toUtf8().constData() );
    runEmptyQuery( query );
    return true;
  }
  else
  {
    return false;
  }
}

void QgsStyle::upgradeIfRequired()
{
  // make sure metadata table exists
  int dbVersion = 0;
  if ( !createStyleMetadataTableIfNeeded() )
  {
    const QString query = qgs_sqlite3_mprintf( "SELECT value FROM stylemetadata WHERE key='version'" );
    int rc;
    sqlite3_statement_unique_ptr statement = mCurrentDB.prepare( query, rc );
    if ( rc == SQLITE_OK && sqlite3_step( statement.get() ) == SQLITE_ROW )
    {
      dbVersion = statement.columnAsText( 0 ).toInt();
    }
  }

  if ( dbVersion < Qgis::versionInt() )
  {
    // do upgrade
    if ( importXml( QgsApplication::defaultStylePath(), dbVersion ) )
    {
      const QString query = qgs_sqlite3_mprintf( "UPDATE stylemetadata SET value='%q' WHERE key='version'", QString::number( Qgis::versionInt() ).toUtf8().constData() );
      runEmptyQuery( query );
    }
  }
}

QString QgsStyle::entityTableName( QgsStyle::StyleEntity type )
{
  switch ( type )
  {
    case SymbolEntity:
      return u"symbol"_s;

    case ColorrampEntity:
      return u"colorramp"_s;

    case TextFormatEntity:
      return u"textformat"_s;

    case LabelSettingsEntity:
      return u"labelsettings"_s;

    case LegendPatchShapeEntity:
      return u"legendpatchshapes"_s;

    case Symbol3DEntity:
      return u"symbol3d"_s;

    case MaterialSettingsEntity:
      return u"materialsettings"_s;

    case TagEntity:
      return u"tag"_s;

    case SmartgroupEntity:
      return u"smartgroup"_s;
  }
  return QString();
}

QString QgsStyle::tagmapTableName( QgsStyle::StyleEntity type )
{
  switch ( type )
  {
    case SymbolEntity:
      return u"tagmap"_s;

    case ColorrampEntity:
      return u"ctagmap"_s;

    case TextFormatEntity:
      return u"tftagmap"_s;

    case LabelSettingsEntity:
      return u"lstagmap"_s;

    case LegendPatchShapeEntity:
      return u"lpstagmap"_s;

    case Symbol3DEntity:
      return u"symbol3dtagmap"_s;

    case MaterialSettingsEntity:
      return u"materialsettingstagmap"_s;

    case TagEntity:
    case SmartgroupEntity:
      break;
  }
  return QString();
}

QString QgsStyle::tagmapEntityIdFieldName( QgsStyle::StyleEntity type )
{
  switch ( type )
  {
    case SymbolEntity:
      return u"symbol_id"_s;

    case ColorrampEntity:
      return u"colorramp_id"_s;

    case TextFormatEntity:
      return u"textformat_id"_s;

    case LabelSettingsEntity:
      return u"labelsettings_id"_s;

    case LegendPatchShapeEntity:
      return u"legendpatchshape_id"_s;

    case Symbol3DEntity:
      return u"symbol3d_id"_s;

    case MaterialSettingsEntity:
      return u"materialsettings_id"_s;

    case TagEntity:
    case SmartgroupEntity:
      break;
  }
  return QString();
}

QgsStyle::StyleEntity QgsStyleSymbolEntity::type() const
{
  return QgsStyle::SymbolEntity;
}

QgsStyle::StyleEntity QgsStyleColorRampEntity::type() const
{
  return QgsStyle::ColorrampEntity;
}

QgsStyle::StyleEntity QgsStyleTextFormatEntity::type() const
{
  return QgsStyle::TextFormatEntity;
}

QgsStyle::StyleEntity QgsStyleLabelSettingsEntity::type() const
{
  return QgsStyle::LabelSettingsEntity;
}

QgsStyle::StyleEntity QgsStyleLegendPatchShapeEntity::type() const
{
  return QgsStyle::LegendPatchShapeEntity;
}

QgsStyle::StyleEntity QgsStyleSymbol3DEntity::type() const
{
  return QgsStyle::Symbol3DEntity;
}

QgsStyle::StyleEntity QgsStyleMaterialSettingsEntity::type() const
{
  return QgsStyle::MaterialSettingsEntity;
}