qgsalgorithmfixgeometrymultipart.cpp

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/***************************************************************************
                        qgsalgorithmfixgeometrymultipart.cpp
                        ---------------------
   begin                : April 2025
   copyright            : (C) 2025 by Jacky Volpes
   email                : jacky dot volpes at oslandia 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 "qgsalgorithmfixgeometrymultipart.h"
 
#include "qgsgeometrycheckerror.h"
#include "qgsgeometrycheckerutils.h"
#include "qgsgeometrymultipartcheck.h"
#include "qgsvectordataproviderfeaturepool.h"
#include "qgsvectorfilewriter.h"
#include "qgsvectorlayer.h"

 
QString QgsFixGeometryMultipartAlgorithm::name() const
{
  return QStringLiteral( "fixgeometrymultipart" );
}
 
QString QgsFixGeometryMultipartAlgorithm::displayName() const
{
  return QObject::tr( "Convert to strictly multipart" );
}
 
QString QgsFixGeometryMultipartAlgorithm::shortDescription() const
{
  return QObject::tr( "Converts features detected with the \"Strictly multipart\" algorithm from the \"Check geometry\" section to singlepart." );
}
 
QStringList QgsFixGeometryMultipartAlgorithm::tags() const
{
  return QObject::tr( "fix,multipart,singlepart" ).split( ',' );
}
 
QString QgsFixGeometryMultipartAlgorithm::group() const
{
  return QObject::tr( "Fix geometry" );
}
 
QString QgsFixGeometryMultipartAlgorithm::groupId() const
{
  return QStringLiteral( "fixgeometry" );
}
 
QString QgsFixGeometryMultipartAlgorithm::shortHelpString() const
{
  return QObject::tr( "This algorithm converts multipart geometries that consists of only one geometry "
                      "into singlepart geometries, based on an error layer from the \"Strict multipart\" algorithm in the \"Check geometry\" section.\n\n"
                      "This algorithm does not change the layer geometry type, which will remain multipart." );
}
 
QgsFixGeometryMultipartAlgorithm *QgsFixGeometryMultipartAlgorithm::createInstance() const
{
  return new QgsFixGeometryMultipartAlgorithm();
}
 
void QgsFixGeometryMultipartAlgorithm::initAlgorithm( const QVariantMap &configuration )
{
  Q_UNUSED( configuration )
 
  addParameter( new QgsProcessingParameterFeatureSource(
    QStringLiteral( "INPUT" ), QObject::tr( "Input layer" ), QList<int>() << static_cast<int>( Qgis::ProcessingSourceType::VectorPolygon ) << static_cast<int>( Qgis::ProcessingSourceType::VectorLine )
  ) );
  addParameter( new QgsProcessingParameterFeatureSource(
    QStringLiteral( "ERRORS" ), QObject::tr( "Error layer" ), QList<int>() << static_cast<int>( Qgis::ProcessingSourceType::VectorPoint )
  ) );
  addParameter( new QgsProcessingParameterField(
    QStringLiteral( "UNIQUE_ID" ), QObject::tr( "Field of original feature unique identifier" ),
    QStringLiteral( "id" ), QStringLiteral( "ERRORS" )
  ) );
 
  addParameter( new QgsProcessingParameterFeatureSink(
    QStringLiteral( "OUTPUT" ), QObject::tr( "Strictly-multipart layer" ), Qgis::ProcessingSourceType::VectorAnyGeometry
  ) );
  addParameter( new QgsProcessingParameterFeatureSink(
    QStringLiteral( "REPORT" ), QObject::tr( "Report layer from fixing multiparts" ), Qgis::ProcessingSourceType::VectorPoint
  ) );
 
  auto tolerance = std::make_unique<QgsProcessingParameterNumber>(
    QStringLiteral( "TOLERANCE" ), QObject::tr( "Tolerance" ), Qgis::ProcessingNumberParameterType::Integer, 8, false, 1, 13
  );
  tolerance->setFlags( tolerance->flags() | Qgis::ProcessingParameterFlag::Advanced );
  tolerance->setHelp( QObject::tr( "The \"Tolerance\" advanced parameter defines the numerical precision of geometric operations, "
                                   "given as an integer n, meaning that any difference smaller than 10⁻ⁿ (in map units) is considered zero." ) );
  addParameter( tolerance.release() );
}
 
QVariantMap QgsFixGeometryMultipartAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  const std::unique_ptr<QgsProcessingFeatureSource> input( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
  if ( !input )
    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT" ) ) );
 
  const std::unique_ptr<QgsProcessingFeatureSource> errors( parameterAsSource( parameters, QStringLiteral( "ERRORS" ), context ) );
  if ( !errors )
    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "ERRORS" ) ) );
 
  QgsProcessingMultiStepFeedback multiStepFeedback( 2, feedback );
 
  const QString featIdFieldName = parameterAsString( parameters, QStringLiteral( "UNIQUE_ID" ), context );
 
  // Verify that input fields exists
  if ( errors->fields().indexFromName( featIdFieldName ) == -1 )
    throw QgsProcessingException( QObject::tr( "Field \"%1\" does not exist in the error layer." ).arg( featIdFieldName ) );
  int inputIdFieldIndex = input->fields().indexFromName( featIdFieldName );
  if ( inputIdFieldIndex == -1 )
    throw QgsProcessingException( QObject::tr( "Field \"%1\" does not exist in input layer." ).arg( featIdFieldName ) );
 
  const QgsField inputFeatIdField = input->fields().at( inputIdFieldIndex );
  if ( inputFeatIdField.type() != errors->fields().at( errors->fields().indexFromName( featIdFieldName ) ).type() )
    throw QgsProcessingException( QObject::tr( "Field \"%1\" does not have the same type as in the error layer." ).arg( featIdFieldName ) );
 
  QString dest_output;
  const std::unique_ptr<QgsFeatureSink> sink_output( parameterAsSink(
    parameters, QStringLiteral( "OUTPUT" ), context, dest_output, input->fields(), input->wkbType(), input->sourceCrs()
  ) );
  if ( !sink_output )
    throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) );
 
  QString dest_report;
  QgsFields reportFields = errors->fields();
  reportFields.append( QgsField( QStringLiteral( "report" ), QMetaType::QString ) );
  reportFields.append( QgsField( QStringLiteral( "error_fixed" ), QMetaType::Bool ) );
  const std::unique_ptr<QgsFeatureSink> sink_report( parameterAsSink(
    parameters, QStringLiteral( "REPORT" ), context, dest_report, reportFields, errors->wkbType(), errors->sourceCrs()
  ) );
  if ( !sink_report )
    throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "REPORT" ) ) );
 
  QgsGeometryCheckContext checkContext = QgsGeometryCheckContext( mTolerance, input->sourceCrs(), context.transformContext(), context.project() );
 
  const QgsGeometryMultipartCheck check( &checkContext, QVariantMap() );
 
  QgsVectorLayer *fixedLayer = input->materialize( QgsFeatureRequest() );
  QgsVectorDataProviderFeaturePool featurePool = QgsVectorDataProviderFeaturePool( fixedLayer );
  QMap<QString, QgsFeaturePool *> featurePools;
  featurePools.insert( fixedLayer->id(), &featurePool );
 
  QgsFeature errorFeature, inputFeature, testDuplicateIdFeature;
  QgsFeatureIterator errorFeaturesIt = errors->getFeatures();
  QList<QgsGeometryCheck::Changes> changesList;
  QgsFeature reportFeature;
  reportFeature.setFields( reportFields );
  long long progression = 0;
  long long totalProgression = errors->featureCount();
  multiStepFeedback.setCurrentStep( 1 );
  multiStepFeedback.setProgressText( QObject::tr( "Fixing errors..." ) );
  while ( errorFeaturesIt.nextFeature( errorFeature ) )
  {
    if ( feedback->isCanceled() )
      break;
 
    progression++;
    multiStepFeedback.setProgress( static_cast<double>( static_cast<long double>( progression ) / totalProgression ) * 100 );
    reportFeature.setGeometry( errorFeature.geometry() );
 
    QString idValue = errorFeature.attribute( featIdFieldName ).toString();
    if ( inputFeatIdField.type() == QMetaType::QString )
      idValue = "'" + idValue + "'";
 
    QgsFeatureIterator it = fixedLayer->getFeatures( QgsFeatureRequest().setFilterExpression( "\"" + featIdFieldName + "\" = " + idValue ) );
    if ( !it.nextFeature( inputFeature ) || !inputFeature.isValid() )
      reportFeature.setAttributes( errorFeature.attributes() << QObject::tr( "Source feature not found or invalid" ) << false );
 
    else if ( it.nextFeature( testDuplicateIdFeature ) )
      throw QgsProcessingException( QObject::tr( "More than one feature found in input layer with value \"%1\" in unique field \"%2\"" ).arg( idValue, featIdFieldName ) );
 
    else if ( inputFeature.geometry().isNull() )
      reportFeature.setAttributes( errorFeature.attributes() << QObject::tr( "Feature geometry is null" ) << false );
 
    else
    {
      QgsGeometryCheckError checkError = QgsGeometryCheckError(
        &check,
        QgsGeometryCheckerUtils::LayerFeature( &featurePool, inputFeature, &checkContext, false ),
        errorFeature.geometry().asPoint(),
        QgsVertexId()
      );
      for ( const QgsGeometryCheck::Changes &changes : std::as_const( changesList ) )
        checkError.handleChanges( changes );
 
      QgsGeometryCheck::Changes changes;
      check.fixError( featurePools, &checkError, QgsGeometryMultipartCheck::ResolutionMethod::ConvertToSingle, QMap<QString, int>(), changes );
      changesList << changes;
      QString resolutionMessage = checkError.resolutionMessage();
      if ( checkError.status() == QgsGeometryCheckError::StatusObsolete )
        resolutionMessage = QObject::tr( "Error is obsolete" );
      reportFeature.setAttributes( errorFeature.attributes() << resolutionMessage << ( checkError.status() == QgsGeometryCheckError::StatusFixed ) );
    }
 
    if ( !sink_report->addFeature( reportFeature, QgsFeatureSink::FastInsert ) )
      throw QgsProcessingException( writeFeatureError( sink_report.get(), parameters, QStringLiteral( "REPORT" ) ) );
  }
  multiStepFeedback.setProgress( 100 );
 
  progression = 0;
  totalProgression = fixedLayer->featureCount();
  multiStepFeedback.setCurrentStep( 2 );
  multiStepFeedback.setProgressText( QObject::tr( "Exporting fixed layer..." ) );
  QgsFeature fixedFeature;
  QgsFeatureIterator fixedFeaturesIt = fixedLayer->getFeatures();
  while ( fixedFeaturesIt.nextFeature( fixedFeature ) )
  {
    if ( feedback->isCanceled() )
      break;
 
    progression++;
    multiStepFeedback.setProgress( static_cast<double>( static_cast<long double>( progression ) / totalProgression ) * 100 );
    if ( !sink_output->addFeature( fixedFeature, QgsFeatureSink::FastInsert ) )
      throw QgsProcessingException( writeFeatureError( sink_output.get(), parameters, QStringLiteral( "OUTPUT" ) ) );
  }
  multiStepFeedback.setProgress( 100 );
 
  QVariantMap outputs;
  outputs.insert( QStringLiteral( "OUTPUT" ), dest_output );
  outputs.insert( QStringLiteral( "REPORT" ), dest_report );
 
  return outputs;
}
 
bool QgsFixGeometryMultipartAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback * )
{
  mTolerance = parameterAsInt( parameters, QStringLiteral( "TOLERANCE" ), context );
 
  return true;
}
 
Qgis::ProcessingAlgorithmFlags QgsFixGeometryMultipartAlgorithm::flags() const
{
  return QgsProcessingAlgorithm::flags() | Qgis::ProcessingAlgorithmFlag::NoThreading | Qgis::ProcessingAlgorithmFlag::RequiresProject;
}