QVariantMap QgsJoinWithLinesAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  if ( parameters.value( QStringLiteral( "SPOKES" ) ) == parameters.value( QStringLiteral( "HUBS" ) ) )
    throw QgsProcessingException( QObject::tr( "Same layer given for both hubs and spokes" ) );

  std::unique_ptr< QgsProcessingFeatureSource > hubSource( parameterAsSource( parameters, QStringLiteral( "HUBS" ), context ) );
  if ( !hubSource )
    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "HUBS" ) ) );

  std::unique_ptr< QgsProcessingFeatureSource > spokeSource( parameterAsSource( parameters, QStringLiteral( "SPOKES" ), context ) );
  if ( !hubSource || !spokeSource )
    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "SPOKES" ) ) );

  QString fieldHubName = parameterAsString( parameters, QStringLiteral( "HUB_FIELD" ), context );
  int fieldHubIndex = hubSource->fields().lookupField( fieldHubName );
  const QStringList hubFieldsToCopy = parameterAsFields( parameters, QStringLiteral( "HUB_FIELDS" ), context );

  QString fieldSpokeName = parameterAsString( parameters, QStringLiteral( "SPOKE_FIELD" ), context );
  int fieldSpokeIndex = spokeSource->fields().lookupField( fieldSpokeName );
  const QStringList spokeFieldsToCopy = parameterAsFields( parameters, QStringLiteral( "SPOKE_FIELDS" ), context );

  if ( fieldHubIndex < 0 || fieldSpokeIndex < 0 )
    throw QgsProcessingException( QObject::tr( "Invalid ID field" ) );

  const bool geodesic = parameterAsBool( parameters, QStringLiteral( "GEODESIC" ), context );
  const double geodesicDistance = parameterAsDouble( parameters, QStringLiteral( "GEODESIC_DISTANCE" ), context ) * 1000;
  bool dynamicGeodesicDistance = QgsProcessingParameters::isDynamic( parameters, QStringLiteral( "GEODESIC_DISTANCE" ) );
  QgsExpressionContext expressionContext = createExpressionContext( parameters, context, hubSource.get() );
  QgsProperty geodesicDistanceProperty;
  if ( dynamicGeodesicDistance )
  {
    geodesicDistanceProperty = parameters.value( QStringLiteral( "GEODESIC_DISTANCE" ) ).value< QgsProperty >();
  }

  const bool splitAntimeridian = parameterAsBool( parameters, QStringLiteral( "ANTIMERIDIAN_SPLIT" ), context );
  QgsDistanceArea da;
  da.setSourceCrs( hubSource->sourceCrs(), context.transformContext() );
  da.setEllipsoid( context.project()->ellipsoid() );

  QgsFields hubOutFields;
  QgsAttributeList hubFieldIndices;
  if ( hubFieldsToCopy.empty() )
  {
    hubOutFields = hubSource->fields();
    hubFieldIndices.reserve( hubOutFields.count() );
    for ( int i = 0; i < hubOutFields.count(); ++i )
    {
      hubFieldIndices << i;
    }
  }
  else
  {
    hubFieldIndices.reserve( hubOutFields.count() );
    for ( const QString &field : hubFieldsToCopy )
    {
      int index = hubSource->fields().lookupField( field );
      if ( index >= 0 )
      {
        hubFieldIndices << index;
        hubOutFields.append( hubSource->fields().at( index ) );
      }
    }
  }

  QgsAttributeList hubFields2Fetch = hubFieldIndices;
  hubFields2Fetch << fieldHubIndex;

  QgsFields spokeOutFields;
  QgsAttributeList spokeFieldIndices;
  if ( spokeFieldsToCopy.empty() )
  {
    spokeOutFields = spokeSource->fields();
    spokeFieldIndices.reserve( spokeOutFields.count() );
    for ( int i = 0; i < spokeOutFields.count(); ++i )
    {
      spokeFieldIndices << i;
    }
  }
  else
  {
    for ( const QString &field : spokeFieldsToCopy )
    {
      int index = spokeSource->fields().lookupField( field );
      if ( index >= 0 )
      {
        spokeFieldIndices << index;
        spokeOutFields.append( spokeSource->fields().at( index ) );
      }
    }
  }

  QgsAttributeList spokeFields2Fetch = spokeFieldIndices;
  spokeFields2Fetch << fieldSpokeIndex;


  QgsFields fields = QgsProcessingUtils::combineFields( hubOutFields, spokeOutFields );

  QgsWkbTypes::Type outType = geodesic ? QgsWkbTypes::MultiLineString : QgsWkbTypes::LineString;
  bool hasZ = false;
  if ( QgsWkbTypes::hasZ( hubSource->wkbType() ) || QgsWkbTypes::hasZ( spokeSource->wkbType() ) )
  {
    outType = QgsWkbTypes::addZ( outType );
    hasZ = true;
  }
  bool hasM = false;
  if ( QgsWkbTypes::hasM( hubSource->wkbType() ) || QgsWkbTypes::hasM( spokeSource->wkbType() ) )
  {
    outType = QgsWkbTypes::addM( outType );
    hasM = true;
  }

  QString dest;
  std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, fields,
                                          outType, hubSource->sourceCrs(), QgsFeatureSink::RegeneratePrimaryKey ) );
  if ( !sink )
    throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) );

  auto getPointFromFeature = [hasZ, hasM]( const QgsFeature & feature )->QgsPoint
  {
    QgsPoint p;
    if ( feature.geometry().type() == QgsWkbTypes::PointGeometry && !feature.geometry().isMultipart() )
      p = *static_cast< const QgsPoint *>( feature.geometry().constGet() );
    else
      p = *static_cast< const QgsPoint *>( feature.geometry().pointOnSurface().constGet() );
    if ( hasZ && !p.is3D() )
      p.addZValue( 0 );
    if ( hasM && !p.isMeasure() )
      p.addMValue( 0 );
    return p;
  };

  QgsFeatureIterator hubFeatures = hubSource->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( hubFields2Fetch ), QgsProcessingFeatureSource::FlagSkipGeometryValidityChecks );
  double step = hubSource->featureCount() > 0 ? 100.0 / hubSource->featureCount() : 1;
  int i = 0;
  QgsFeature hubFeature;
  while ( hubFeatures.nextFeature( hubFeature ) )
  {
    i++;
    if ( feedback->isCanceled() )
    {
      break;
    }

    feedback->setProgress( i * step );

    if ( !hubFeature.hasGeometry() )
      continue;

    QgsPoint hubPoint = getPointFromFeature( hubFeature );

    // only keep selected attributes
    QgsAttributes hubAttributes;
    for ( int j = 0; j < hubFeature.attributes().count(); ++j )
    {
      if ( !hubFieldIndices.contains( j ) )
        continue;
      hubAttributes << hubFeature.attribute( j );
    }

    QgsFeatureRequest spokeRequest = QgsFeatureRequest().setDestinationCrs( hubSource->sourceCrs(), context.transformContext() );
    spokeRequest.setSubsetOfAttributes( spokeFields2Fetch );
    spokeRequest.setFilterExpression( QgsExpression::createFieldEqualityExpression( fieldSpokeName, hubFeature.attribute( fieldHubIndex ) ) );

    QgsFeatureIterator spokeFeatures = spokeSource->getFeatures( spokeRequest, QgsProcessingFeatureSource::FlagSkipGeometryValidityChecks );
    QgsFeature spokeFeature;
    while ( spokeFeatures.nextFeature( spokeFeature ) )
    {
      if ( feedback->isCanceled() )
      {
        break;
      }
      if ( !spokeFeature.hasGeometry() )
        continue;

      QgsPoint spokePoint = getPointFromFeature( spokeFeature );
      QgsGeometry line;
      if ( !geodesic )
      {
        line = QgsGeometry( new QgsLineString( QVector< QgsPoint >() << hubPoint << spokePoint ) );
        if ( splitAntimeridian )
          line = da.splitGeometryAtAntimeridian( line );
      }
      else
      {
        double distance = geodesicDistance;
        if ( dynamicGeodesicDistance )
        {
          expressionContext.setFeature( hubFeature );
          distance = geodesicDistanceProperty.valueAsDouble( expressionContext, distance );
        }

        std::unique_ptr< QgsMultiLineString > ml = qgis::make_unique< QgsMultiLineString >();
        std::unique_ptr< QgsLineString > l = qgis::make_unique< QgsLineString >( QVector< QgsPoint >() << hubPoint );
        QVector< QVector< QgsPointXY > > points = da.geodesicLine( QgsPointXY( hubPoint ), QgsPointXY( spokePoint ), distance, splitAntimeridian );
        QVector< QgsPointXY > points1 = points.at( 0 );
        points1.pop_front();
        if ( points.count() == 1 )
          points1.pop_back();

        QgsLineString geodesicPoints( points1 );
        l->append( &geodesicPoints );
        if ( points.count() == 1 )
          l->addVertex( spokePoint );

        ml->addGeometry( l.release() );
        if ( points.count() > 1 )
        {
          QVector< QgsPointXY > points2 = points.at( 1 );
          points2.pop_back();
          l = qgis::make_unique< QgsLineString >( points2 );
          if ( hasZ )
            l->addZValue( std::numeric_limits<double>::quiet_NaN() );
          if ( hasM )
            l->addMValue( std::numeric_limits<double>::quiet_NaN() );

          l->addVertex( spokePoint );
          ml->addGeometry( l.release() );
        }
        line = QgsGeometry( std::move( ml ) );
      }

      QgsFeature outFeature;
      QgsAttributes outAttributes = hubAttributes;

      // only keep selected attributes
      QgsAttributes spokeAttributes;
      for ( int j = 0; j < spokeFeature.attributes().count(); ++j )
      {
        if ( !spokeFieldIndices.contains( j ) )
          continue;
        spokeAttributes << spokeFeature.attribute( j );
      }

      outAttributes.append( spokeAttributes );
      outFeature.setAttributes( outAttributes );
      outFeature.setGeometry( line );
      sink->addFeature( outFeature, QgsFeatureSink::FastInsert );
    }
  }

  QVariantMap outputs;
  outputs.insert( QStringLiteral( "OUTPUT" ), dest );
  return outputs;
}
QVariantMap QgsJoinWithLinesAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  if ( parameters.value( QStringLiteral( "SPOKES" ) ) == parameters.value( QStringLiteral( "HUBS" ) ) )
    throw QgsProcessingException( QObject::tr( "Same layer given for both hubs and spokes" ) );

  std::unique_ptr< QgsFeatureSource > hubSource( parameterAsSource( parameters, QStringLiteral( "HUBS" ), context ) );
  std::unique_ptr< QgsFeatureSource > spokeSource( parameterAsSource( parameters, QStringLiteral( "SPOKES" ), context ) );
  if ( !hubSource || !spokeSource )
    return QVariantMap();

  QString fieldHubName = parameterAsString( parameters, QStringLiteral( "HUB_FIELD" ), context );
  int fieldHubIndex = hubSource->fields().lookupField( fieldHubName );
  const QStringList hubFieldsToCopy = parameterAsFields( parameters, QStringLiteral( "HUB_FIELDS" ), context );

  QString fieldSpokeName = parameterAsString( parameters, QStringLiteral( "SPOKE_FIELD" ), context );
  int fieldSpokeIndex = spokeSource->fields().lookupField( fieldSpokeName );
  const QStringList spokeFieldsToCopy = parameterAsFields( parameters, QStringLiteral( "SPOKE_FIELDS" ), context );

  if ( fieldHubIndex < 0 || fieldSpokeIndex < 0 )
    throw QgsProcessingException( QObject::tr( "Invalid ID field" ) );

  QgsFields hubOutFields;
  QgsAttributeList hubFieldIndices;
  if ( hubFieldsToCopy.empty() )
  {
    hubOutFields = hubSource->fields();
    for ( int i = 0; i < hubOutFields.count(); ++i )
    {
      hubFieldIndices << i;
    }
  }
  else
  {
    for ( const QString &field : hubFieldsToCopy )
    {
      int index = hubSource->fields().lookupField( field );
      if ( index >= 0 )
      {
        hubFieldIndices << index;
        hubOutFields.append( hubSource->fields().at( index ) );
      }
    }
  }

  QgsAttributeList hubFields2Fetch = hubFieldIndices;
  hubFields2Fetch << fieldHubIndex;

  QgsFields spokeOutFields;
  QgsAttributeList spokeFieldIndices;
  if ( spokeFieldsToCopy.empty() )
  {
    spokeOutFields = spokeSource->fields();
    for ( int i = 0; i < spokeOutFields.count(); ++i )
    {
      spokeFieldIndices << i;
    }
  }
  else
  {
    for ( const QString &field : spokeFieldsToCopy )
    {
      int index = spokeSource->fields().lookupField( field );
      if ( index >= 0 )
      {
        spokeFieldIndices << index;
        spokeOutFields.append( spokeSource->fields().at( index ) );
      }
    }
  }

  QgsAttributeList spokeFields2Fetch = spokeFieldIndices;
  spokeFields2Fetch << fieldSpokeIndex;


  QgsFields fields = QgsProcessingUtils::combineFields( hubOutFields, spokeOutFields );

  QgsWkbTypes::Type outType = QgsWkbTypes::LineString;
  bool hasZ = false;
  if ( QgsWkbTypes::hasZ( hubSource->wkbType() ) || QgsWkbTypes::hasZ( spokeSource->wkbType() ) )
  {
    outType = QgsWkbTypes::addZ( outType );
    hasZ = true;
  }
  bool hasM = false;
  if ( QgsWkbTypes::hasM( hubSource->wkbType() ) || QgsWkbTypes::hasM( spokeSource->wkbType() ) )
  {
    outType = QgsWkbTypes::addM( outType );
    hasM = true;
  }

  QString dest;
  std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest, fields,
                                          outType, hubSource->sourceCrs() ) );
  if ( !sink )
    return QVariantMap();

  auto getPointFromFeature = [hasZ, hasM]( const QgsFeature & feature )->QgsPoint
  {
    QgsPoint p;
    if ( feature.geometry().type() == QgsWkbTypes::PointGeometry && !feature.geometry().isMultipart() )
      p = *static_cast< const QgsPoint *>( feature.geometry().constGet() );
    else
      p = *static_cast< const QgsPoint *>( feature.geometry().pointOnSurface().constGet() );
    if ( hasZ && !p.is3D() )
      p.addZValue( 0 );
    if ( hasM && !p.isMeasure() )
      p.addMValue( 0 );
    return p;
  };

  QgsFeatureIterator hubFeatures = hubSource->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( hubFields2Fetch ) );
  double step = hubSource->featureCount() > 0 ? 100.0 / hubSource->featureCount() : 1;
  int i = 0;
  QgsFeature hubFeature;
  while ( hubFeatures.nextFeature( hubFeature ) )
  {
    i++;
    if ( feedback->isCanceled() )
    {
      break;
    }

    feedback->setProgress( i * step );

    if ( !hubFeature.hasGeometry() )
      continue;

    QgsPoint hubPoint = getPointFromFeature( hubFeature );

    // only keep selected attributes
    QgsAttributes hubAttributes;
    for ( int j = 0; j < hubFeature.attributes().count(); ++j )
    {
      if ( !hubFieldIndices.contains( j ) )
        continue;
      hubAttributes << hubFeature.attribute( j );
    }

    QgsFeatureRequest spokeRequest = QgsFeatureRequest().setDestinationCrs( hubSource->sourceCrs(), context.transformContext() );
    spokeRequest.setSubsetOfAttributes( spokeFields2Fetch );
    spokeRequest.setFilterExpression( QgsExpression::createFieldEqualityExpression( fieldSpokeName, hubFeature.attribute( fieldHubIndex ) ) );

    QgsFeatureIterator spokeFeatures = spokeSource->getFeatures( spokeRequest );
    QgsFeature spokeFeature;
    while ( spokeFeatures.nextFeature( spokeFeature ) )
    {
      if ( feedback->isCanceled() )
      {
        break;
      }
      if ( !spokeFeature.hasGeometry() )
        continue;

      QgsPoint spokePoint = getPointFromFeature( spokeFeature );
      QgsGeometry line( new QgsLineString( QVector< QgsPoint >() << hubPoint << spokePoint ) );

      QgsFeature outFeature;
      QgsAttributes outAttributes = hubAttributes;

      // only keep selected attributes
      QgsAttributes spokeAttributes;
      for ( int j = 0; j < spokeFeature.attributes().count(); ++j )
      {
        if ( !spokeFieldIndices.contains( j ) )
          continue;
        spokeAttributes << spokeFeature.attribute( j );
      }

      outAttributes.append( spokeAttributes );
      outFeature.setAttributes( outAttributes );
      outFeature.setGeometry( line );
      sink->addFeature( outFeature, QgsFeatureSink::FastInsert );
    }
  }

  QVariantMap outputs;
  outputs.insert( QStringLiteral( "OUTPUT" ), dest );
  return outputs;
}