QGIS/external/mdal/frmts/mdal_flo2d.cpp

/*
 MDAL - Mesh Data Abstraction Library (MIT License)
 Copyright (C) 2016 Lutra Consulting
 Copyright (C) 2018 Peter Petrik (zilolv at gmail dot com)
*/

#include "mdal_flo2d.hpp"
#include <vector>
#include <map>
#include <iosfwd>
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <cmath>
#include <cstring>
#include <assert.h>

#include "mdal_utils.hpp"
#include "mdal_hdf5.hpp"
#include "mdal_logger.hpp"

#define FLO2D_NAN 0.0

struct VertexCompare
{
  bool operator()( const MDAL::Vertex &lhs, const MDAL::Vertex &rhs ) const
  {
    double resX = 0;
    resX += lhs.x * 1000000;
    resX += lhs.y * 1000;

    double resY = 0;
    resY += rhs.x * 1000000;
    resY += rhs.y * 1000;

    return resX < resY;
  }
};

static std::string fileNameFromDir( const std::string &mainFileName, const std::string &name )
{
  std::string dir = MDAL::dirName( mainFileName );
  return MDAL::pathJoin( dir, name );
}

static double getDouble( double val )
{
  if ( MDAL::equals( val, FLO2D_NAN, 1e-8 ) )
  {
    return MDAL_NAN;
  }
  else
  {
    return val;
  }
}

static double toFlo2DDouble( double val )
{
  if ( std::isnan( val ) )
  {
    return FLO2D_NAN;
  }
  else
  {
    return val;
  }
}

static double getDouble( const std::string &val )
{
  double valF = MDAL::toDouble( val );
  return getDouble( valF );
}

void MDAL::DriverFlo2D::addStaticDataset(
  std::vector<double> &vals,
  const std::string &groupName,
  const std::string &datFileName )
{
  std::shared_ptr<DatasetGroup> group = std::make_shared< DatasetGroup >(
                                          name(),
                                          mMesh.get(),
                                          datFileName,
                                          groupName
                                        );
  group->setDataLocation( MDAL_DataLocation::DataOnFaces );
  group->setIsScalar( true );

  std::shared_ptr<MDAL::MemoryDataset2D> dataset = std::make_shared< MemoryDataset2D >( group.get() );
  assert( vals.size() == dataset->valuesCount() );
  dataset->setTime( MDAL::RelativeTimestamp() );
  double *values = dataset->values();
  memcpy( values, vals.data(), vals.size() * sizeof( double ) );
  dataset->setStatistics( MDAL::calculateStatistics( dataset ) );
  group->datasets.push_back( dataset );
  group->setStatistics( MDAL::calculateStatistics( group ) );
  mMesh->datasetGroups.push_back( group );
}

void MDAL::DriverFlo2D::parseCADPTSFile( const std::string &datFileName, std::vector<CellCenter> &cells )
{
  std::string cadptsFile( fileNameFromDir( datFileName, "CADPTS.DAT" ) );
  if ( !MDAL::fileExists( cadptsFile ) )
  {
    throw MDAL::Error( MDAL_Status::Err_FileNotFound, "Could not find file " + cadptsFile );
  }

  std::ifstream cadptsStream( cadptsFile, std::ifstream::in );
  std::string line;
  // CADPTS.DAT - COORDINATES OF CELL CENTERS (ELEM NUM, X, Y)
  while ( std::getline( cadptsStream, line ) )
  {
    line = MDAL::rtrim( line );
    std::vector<std::string> lineParts = MDAL::split( line, ' ' );
    if ( lineParts.size() != 3 )
    {
      throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Error while loading CADPTS file, wrong lineparts count (3)" );
    }
    CellCenter cc;
    cc.id = MDAL::toSizeT( lineParts[1] ) - 1; //numbered from 1
    cc.x = MDAL::toDouble( lineParts[1] );
    cc.y = MDAL::toDouble( lineParts[2] );
    cc.conn.resize( 4 );
    cells.push_back( cc );
  }
}

void MDAL::DriverFlo2D::parseFPLAINFile( std::vector<double> &elevations,
    const std::string &datFileName,
    std::vector<CellCenter> &cells )
{
  elevations.clear();
  // FPLAIN.DAT - CONNECTIVITY (ELEM NUM, ELEM N, ELEM E, ELEM S, ELEM W, MANNING-N, BED ELEVATION)
  std::string fplainFile( fileNameFromDir( datFileName, "FPLAIN.DAT" ) );
  if ( !MDAL::fileExists( fplainFile ) )
  {
    throw MDAL::Error( MDAL_Status::Err_FileNotFound, "Could not find file " + fplainFile );
  }

  std::ifstream fplainStream( fplainFile, std::ifstream::in );
  std::string line;

  while ( std::getline( fplainStream, line ) )
  {
    line = MDAL::rtrim( line );
    std::vector<std::string> lineParts = MDAL::split( line, ' ' );
    if ( lineParts.size() != 7 )
    {
      throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Error while loading Fplain file, wrong lineparts count (7)" );
    }
    size_t cc_i = MDAL::toSizeT( lineParts[0] ) - 1; //numbered from 1
    for ( size_t j = 0; j < 4; ++j )
    {
      cells[cc_i].conn[j] = MDAL::toInt( lineParts[j + 1] ) - 1; //numbered from 1, 0 boundary Vertex
    }
    elevations.push_back( MDAL::toDouble( lineParts[6] ) );
  }
}

static void addDatasetToGroup( std::shared_ptr<MDAL::DatasetGroup> group, std::shared_ptr<MDAL::MemoryDataset2D> dataset )
{
  if ( group && dataset && dataset->valuesCount() > 0 )
  {
    dataset->setStatistics( MDAL::calculateStatistics( dataset ) );
    group->datasets.push_back( dataset );
  }
}

void MDAL::DriverFlo2D::parseTIMDEPFile( const std::string &datFileName, const std::vector<double> &elevations )
{
  // TIMDEP.OUT
  // this file is optional, so if not present, reading is skipped
  // time (separate line)
  // For every Vertex:
  // FLO2D: ELEM NUMber (indexed from 1), depth, velocity, velocity x, velocity y
  // FLO2DPro: ELEM NUMber (indexed from 1), depth, velocity, velocity x, velocity y, water surface elevation
  std::string inFile( fileNameFromDir( datFileName, "TIMDEP.OUT" ) );
  if ( !MDAL::fileExists( inFile ) )
  {
    return;
  }

  std::ifstream inStream( inFile, std::ifstream::in );
  std::string line;

  size_t nVertexs = mMesh->verticesCount();
  size_t ntimes = 0;

  RelativeTimestamp time = RelativeTimestamp();
  size_t face_idx = 0;

  std::shared_ptr<DatasetGroup> depthDsGroup = std::make_shared< DatasetGroup >(
        name(),
        mMesh.get(),
        datFileName,
        "Depth"
      );
  depthDsGroup->setDataLocation( MDAL_DataLocation::DataOnFaces );
  depthDsGroup->setIsScalar( true );


  std::shared_ptr<DatasetGroup> waterLevelDsGroup = std::make_shared< DatasetGroup >(
        name(),
        mMesh.get(),
        datFileName,
        "Water Level"
      );
  waterLevelDsGroup->setDataLocation( MDAL_DataLocation::DataOnFaces );
  waterLevelDsGroup->setIsScalar( true );

  std::shared_ptr<DatasetGroup> flowDsGroup = std::make_shared< DatasetGroup >(
        name(),
        mMesh.get(),
        datFileName,
        "Velocity"
      );
  flowDsGroup->setDataLocation( MDAL_DataLocation::DataOnFaces );
  flowDsGroup->setIsScalar( false );

  std::shared_ptr<MDAL::MemoryDataset2D> flowDataset;
  std::shared_ptr<MDAL::MemoryDataset2D> depthDataset;
  std::shared_ptr<MDAL::MemoryDataset2D> waterLevelDataset;

  while ( std::getline( inStream, line ) )
  {
    line = MDAL::rtrim( line );
    std::vector<std::string> lineParts = MDAL::split( line, ' ' );
    if ( lineParts.size() == 1 )
    {
      time = RelativeTimestamp( MDAL::toDouble( line ), RelativeTimestamp::hours );
      ntimes++;

      if ( depthDataset ) addDatasetToGroup( depthDsGroup, depthDataset );
      if ( flowDataset ) addDatasetToGroup( flowDsGroup, flowDataset );
      if ( waterLevelDataset ) addDatasetToGroup( waterLevelDsGroup, waterLevelDataset );

      depthDataset  = std::make_shared< MemoryDataset2D >( depthDsGroup.get() );
      flowDataset = std::make_shared< MemoryDataset2D >( flowDsGroup.get() );
      waterLevelDataset = std::make_shared< MemoryDataset2D >( waterLevelDsGroup.get() );

      depthDataset->setTime( time );
      flowDataset->setTime( time );
      waterLevelDataset->setTime( time );

      face_idx = 0;

    }
    else if ( ( lineParts.size() == 5 ) || ( lineParts.size() == 6 ) )
    {
      // new Vertex for time
      if ( !depthDataset || !flowDataset || !waterLevelDataset ) throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Depth, flow or water level dataset is not valid (null)" );
      if ( face_idx == nVertexs ) throw MDAL::Error( MDAL_Status::Err_IncompatibleMesh, "Invalid face id" );

      // this is magnitude: getDouble(lineParts[2]);
      flowDataset->setVectorValue( face_idx, getDouble( lineParts[3] ),  getDouble( lineParts[4] ) );

      double depth = getDouble( lineParts[1] );
      depthDataset->setScalarValue( face_idx, depth );

      if ( !std::isnan( depth ) ) depth += elevations[face_idx];
      waterLevelDataset->setScalarValue( face_idx, depth );

      face_idx ++;
    }
    else
    {
      throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Unable to load TIMDEP file, found unknown format" );
    }
  }

  if ( depthDataset ) addDatasetToGroup( depthDsGroup, depthDataset );
  if ( flowDataset ) addDatasetToGroup( flowDsGroup, flowDataset );
  if ( waterLevelDataset ) addDatasetToGroup( waterLevelDsGroup, waterLevelDataset );

  depthDsGroup->setStatistics( MDAL::calculateStatistics( depthDsGroup ) );
  flowDsGroup->setStatistics( MDAL::calculateStatistics( flowDsGroup ) );
  waterLevelDsGroup->setStatistics( MDAL::calculateStatistics( waterLevelDsGroup ) );

  mMesh->datasetGroups.push_back( depthDsGroup );
  mMesh->datasetGroups.push_back( flowDsGroup );
  mMesh->datasetGroups.push_back( waterLevelDsGroup );
}


void MDAL::DriverFlo2D::parseDEPTHFile( const std::string &datFileName, const std::vector<double> &elevations )
{
  // this file is optional, so if not present, reading is skipped
  std::string depthFile( fileNameFromDir( datFileName, "DEPTH.OUT" ) );
  if ( !MDAL::fileExists( depthFile ) )
  {
    return; //optional file
  }

  std::ifstream depthStream( depthFile, std::ifstream::in );
  std::string line;

  size_t nFaces = mMesh->facesCount();
  std::vector<double> maxDepth( nFaces );
  std::vector<double> maxWaterLevel( nFaces );

  size_t vertex_idx = 0;

  // DEPTH.OUT - COORDINATES (ELEM NUM, X, Y, MAX DEPTH)
  while ( std::getline( depthStream, line ) )
  {
    line = MDAL::rtrim( line );
    if ( vertex_idx == nFaces ) throw MDAL::Error( MDAL_Status::Err_IncompatibleMesh, "Error while loading DEPTH file, invalid vertex index" );

    std::vector<std::string> lineParts = MDAL::split( line, ' ' );
    if ( lineParts.size() != 4 )
    {
      throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Error while loading DEPTH file, wrong lineparts count (4)" );
    }

    double val = getDouble( lineParts[3] );
    maxDepth[vertex_idx] = val;

    //water level
    if ( !std::isnan( val ) ) val += elevations[vertex_idx];
    maxWaterLevel[vertex_idx] = val;


    vertex_idx++;
  }

  addStaticDataset( maxDepth, "Depth/Maximums", datFileName );
  addStaticDataset( maxWaterLevel, "Water Level/Maximums", datFileName );
}


void MDAL::DriverFlo2D::parseVELFPVELOCFile( const std::string &datFileName )
{
  // these files are optional, so if not present, reading is skipped
  size_t nFaces = mMesh->facesCount();
  std::vector<double> maxVel( nFaces );

  {
    std::string velocityFile( fileNameFromDir( datFileName, "VELFP.OUT" ) );
    if ( !MDAL::fileExists( velocityFile ) )
    {
      return; //optional file
    }

    std::ifstream velocityStream( velocityFile, std::ifstream::in );
    std::string line;

    size_t vertex_idx = 0;

    // VELFP.OUT - COORDINATES (ELEM NUM, X, Y, MAX VEL) - Maximum floodplain flow velocity;
    while ( std::getline( velocityStream, line ) )
    {
      if ( vertex_idx == nFaces ) throw MDAL::Error( MDAL_Status::Err_IncompatibleMesh, "Error while loading VELFP file, invalid vertex index" );

      line = MDAL::rtrim( line );
      std::vector<std::string> lineParts = MDAL::split( line, ' ' );
      if ( lineParts.size() != 4 )
      {
        throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Error while loading VELFP file, wrong lineparts count (4)" );
      }

      double val = getDouble( lineParts[3] );
      maxVel[vertex_idx] = val;

      vertex_idx++;
    }
  }

  {
    std::string velocityFile( fileNameFromDir( datFileName, "VELOC.OUT" ) );
    if ( !MDAL::fileExists( velocityFile ) )
    {
      return; //optional file
    }

    std::ifstream velocityStream( velocityFile, std::ifstream::in );
    std::string line;

    size_t vertex_idx = 0;

    // VELOC.OUT - COORDINATES (ELEM NUM, X, Y, MAX VEL)  - Maximum channel flow velocity
    while ( std::getline( velocityStream, line ) )
    {
      if ( vertex_idx == nFaces ) throw MDAL::Error( MDAL_Status::Err_IncompatibleMesh, "Error while loading VELOC file, invalid vertex index" );

      line = MDAL::rtrim( line );
      std::vector<std::string> lineParts = MDAL::split( line, ' ' );
      if ( lineParts.size() != 4 )
      {
        throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Error while loading VELOC file, wrong lineparts count (4)" );
      }

      double val = getDouble( lineParts[3] );
      if ( !std::isnan( val ) )  // overwrite value from VELFP if it is not 0
      {
        maxVel[vertex_idx] = val;
      }

      vertex_idx++;
    }
  }

  addStaticDataset( maxVel, "Velocity/Maximums", datFileName );
}

double MDAL::DriverFlo2D::calcCellSize( const std::vector<CellCenter> &cells )
{
  // find first cell that is not izolated from the others
  // and return its distance to the neighbor's cell center
  for ( size_t i = 0; i < cells.size(); ++i )
  {
    for ( size_t j = 0; j < 4; ++j )
    {
      int idx = cells[i].conn[0];
      if ( idx > -1 )
      {
        if ( ( j == 0 ) || ( j == 2 ) )
        {
          return fabs( cells[static_cast<size_t>( idx )].y - cells[i].y );
        }
        else
        {
          return fabs( cells[static_cast<size_t>( idx )].x - cells[i].x );
        }
      }
    }
  }
  throw MDAL::Error( MDAL_Status::Err_IncompatibleMesh, "Did not find izolated cell" );
}

MDAL::Vertex MDAL::DriverFlo2D::createVertex( size_t position, double half_cell_size, const CellCenter &cell )
{
  MDAL::Vertex n;
  n.x = cell.x;
  n.y = cell.y;

  switch ( position )
  {
    case 0:
      n.x += half_cell_size;
      n.y -= half_cell_size;
      break;

    case 1:
      n.x += half_cell_size;
      n.y += half_cell_size;
      break;

    case 2:
      n.x -= half_cell_size;
      n.y += half_cell_size;
      break;

    case 3:
      n.x -= half_cell_size;
      n.y -= half_cell_size;
      break;
  }

  return n;
}

void MDAL::DriverFlo2D::createMesh( const std::vector<CellCenter> &cells, double half_cell_size )
{
  // Create all Faces from cell centers.
  // Vertexs must be also created, they are not stored in FLO-2D files
  // try to reuse Vertexs already created for other Faces by usage of unique_Vertexs set.
  Faces faces;
  Vertices vertices;
  std::map<Vertex, size_t, VertexCompare> unique_vertices; //vertex -> id
  size_t vertex_idx = 0;

  for ( size_t i = 0; i < cells.size(); ++i )
  {
    Face e( 4 );

    for ( size_t position = 0; position < 4; ++position )
    {
      Vertex n = createVertex( position, half_cell_size, cells[i] );
      const auto iter = unique_vertices.find( n );
      if ( iter == unique_vertices.end() )
      {
        unique_vertices[n] = vertex_idx;
        vertices.push_back( n );
        e[position] = vertex_idx;
        ++vertex_idx;
      }
      else
      {
        e[position] = iter->second;
      }
    }

    faces.push_back( e );
  }

  mMesh.reset(
    new MemoryMesh(
      name(),
      vertices.size(),
      0,
      faces.size(),
      4, //maximum quads
      computeExtent( vertices ),
      mDatFileName
    )
  );
  mMesh->faces = faces;
  mMesh->vertices = vertices;
}

bool MDAL::DriverFlo2D::parseHDF5Datasets( MemoryMesh *mesh, const std::string &timedepFileName )
{
  //return true on error

  size_t nFaces =  mesh->facesCount();
  if ( !fileExists( timedepFileName ) ) return true;

  HdfFile file( timedepFileName, HdfFile::ReadOnly );
  if ( !file.isValid() ) return true;

  HdfGroup timedataGroup = file.group( "TIMDEP NETCDF OUTPUT RESULTS" );
  if ( !timedataGroup.isValid() ) return true;

  std::vector<std::string> groupNames = timedataGroup.groups();

  for ( const std::string &grpName : groupNames )
  {
    HdfGroup grp = timedataGroup.group( grpName );
    if ( !grp.isValid() ) return true;

    HdfAttribute groupType = grp.attribute( "Grouptype" );
    if ( !groupType.isValid() ) return true;

    HdfAttribute timeUnitAttribute = grp.attribute( "TimeUnits" );
    std::string timeUnitString = timeUnitAttribute.readString();

    /* Min and Max arrays in TIMDEP.HDF5 files have dimensions 1xntimesteps .
        HdfDataset minDs = grp.dataset("Mins");
        if (!minDs.isValid()) return true;

        HdfDataset maxDs = grp.dataset("Maxs");
        if (!maxDs.isValid()) return true;
    */

    HdfDataset timesDs = grp.dataset( "Times" );
    if ( !timesDs.isValid() ) return true;
    size_t timesteps = timesDs.elementCount();

    HdfDataset valuesDs = grp.dataset( "Values" );
    if ( !valuesDs.isValid() ) return true;

    bool isVector = MDAL::contains( groupType.readString(), "vector", ContainsBehaviour::CaseInsensitive );

    // Some sanity checks
    size_t expectedSize = mesh->facesCount() * timesteps;
    if ( isVector ) expectedSize *= 2;
    if ( valuesDs.elementCount() != expectedSize ) return true;

    // Read data
    std::vector<double> times = timesDs.readArrayDouble();
    std::vector<float> values = valuesDs.readArray();

    // Create dataset now
    std::shared_ptr<DatasetGroup> ds = std::make_shared< DatasetGroup >(
                                         name(),
                                         mesh,
                                         timedepFileName,
                                         grpName
                                       );
    ds->setDataLocation( MDAL_DataLocation::DataOnFaces );
    ds->setIsScalar( !isVector );

    for ( size_t ts = 0; ts < timesteps; ++ts )
    {
      std::shared_ptr< MemoryDataset2D > output = std::make_shared< MemoryDataset2D >( ds.get() );
      output->setTime( times[ts], parseDurationTimeUnit( timeUnitString ) );

      if ( isVector )
      {
        // vector
        for ( size_t i = 0; i < nFaces; ++i )
        {
          size_t idx = 2 * ( ts * nFaces + i );
          double x = getDouble( static_cast<double>( values[idx] ) );
          double y = getDouble( static_cast<double>( values[idx + 1] ) );
          output->setVectorValue( i, x, y );
        }
      }
      else
      {
        // scalar
        for ( size_t i = 0; i < nFaces; ++i )
        {
          size_t idx = ts * nFaces + i;
          double val = getDouble( static_cast<double>( values[idx] ) );
          output->setScalarValue( i, val );
        }
      }
      addDatasetToGroup( ds, output );
    }

    // TODO use mins & maxs arrays
    ds->setStatistics( MDAL::calculateStatistics( ds ) );
    mesh->datasetGroups.push_back( ds );

  }

  return false;
}

void MDAL::DriverFlo2D::parseOUTDatasets( const std::string &datFileName, const std::vector<double> &elevations )
{
  // Create Depth and Velocity datasets Time varying datasets
  parseTIMDEPFile( datFileName, elevations );

  // Maximum Depth and Water Level
  parseDEPTHFile( datFileName, elevations );

  // Maximum Velocity
  parseVELFPVELOCFile( datFileName );
}

MDAL::DriverFlo2D::DriverFlo2D()
  : Driver(
      "FLO2D",
      "Flo2D",
      "*.nc",
      Capability::ReadMesh | Capability::ReadDatasets | Capability::WriteDatasetsOnFaces )
{

}

MDAL::DriverFlo2D *MDAL::DriverFlo2D::create()
{
  return new DriverFlo2D();
}

bool MDAL::DriverFlo2D::canReadMesh( const std::string &uri )
{
  std::string cadptsFile( fileNameFromDir( uri, "CADPTS.DAT" ) );
  if ( !MDAL::fileExists( cadptsFile ) )
  {
    return false;
  }

  std::string fplainFile( fileNameFromDir( uri, "FPLAIN.DAT" ) );
  if ( !MDAL::fileExists( fplainFile ) )
  {
    return false;
  }

  return true;
}

bool MDAL::DriverFlo2D::canReadDatasets( const std::string &uri )
{
  if ( !fileExists( uri ) ) return false;

  HdfFile file( uri, HdfFile::ReadOnly );
  if ( !file.isValid() ) return false;

  HdfGroup timedataGroup = file.group( "TIMDEP NETCDF OUTPUT RESULTS" );
  if ( !timedataGroup.isValid() ) return false;

  return true;
}

void MDAL::DriverFlo2D::load( const std::string &uri, MDAL::Mesh *mesh )
{
  MDAL::Log::resetLastStatus();

  MDAL::MemoryMesh *memoryMesh = dynamic_cast<MDAL::MemoryMesh *>( mesh );
  if ( !memoryMesh )
  {
    MDAL::Log::error( MDAL_Status::Err_IncompatibleMesh, name(), "Mesh is not valid (null)" );
    return;
  }

  if ( !MDAL::fileExists( uri ) )
  {
    MDAL::Log::error( MDAL_Status::Err_FileNotFound, name(), "Could not find file " + uri );
    return;
  }

  bool err = parseHDF5Datasets( memoryMesh, uri );
  if ( err )
  {
    MDAL::Log::error( MDAL_Status::Err_InvalidData, name(), "Could not parse HDF5 datasets" );
  }
}

std::unique_ptr< MDAL::Mesh > MDAL::DriverFlo2D::load( const std::string &resultsFile, const std::string & )
{
  mDatFileName = resultsFile;
  MDAL::Log::resetLastStatus();
  mMesh.reset();
  std::vector<CellCenter> cells;

  try
  {
    // Parse mMesh info
    parseCADPTSFile( mDatFileName, cells );
    std::vector<double> elevations;
    parseFPLAINFile( elevations, mDatFileName, cells );
    double cell_size = calcCellSize( cells );

    // Create mMesh
    createMesh( cells, cell_size / 2.0 );

    // create output for bed elevation
    addStaticDataset( elevations, "Bed Elevation", mDatFileName );

    // check if we have HDF5 file
    std::string TIMDEPFileName = fileNameFromDir( mDatFileName, "TIMDEP.HDF5" );
    if ( parseHDF5Datasets( mMesh.get(), TIMDEPFileName ) )
    {
      // some problem with HDF5 data, try text files
      parseOUTDatasets( mDatFileName, elevations );
    }
  }

  catch ( MDAL_Status error )
  {
    MDAL::Log::error( error, name(), "error occurred while loading file " + resultsFile );
    mMesh.reset();
  }
  catch ( MDAL::Error err )
  {
    MDAL::Log::error( err, name() );
  }

  return std::unique_ptr<Mesh>( mMesh.release() );
}


bool MDAL::DriverFlo2D::addToHDF5File( DatasetGroup *group )
{
  assert( MDAL::fileExists( group->uri() ) );
  HdfFile file( group->uri(), HdfFile::ReadWrite );
  if ( !file.isValid() ) return true;

  HdfGroup timedataGroup = file.group( "TIMDEP NETCDF OUTPUT RESULTS" );
  if ( !timedataGroup.isValid() ) return true;
  return appendGroup( file, group, timedataGroup );
}


bool MDAL::DriverFlo2D::saveNewHDF5File( DatasetGroup *dsGroup )
{
  // Create file
  HdfFile file( dsGroup->uri(), HdfFile::Create );
  // Unable to create
  if ( !file.isValid() ) return true;

  // Create float dataset File Version
  HdfDataset dsFileVersion( file.id(), "/File Version", H5T_NATIVE_FLOAT );
  dsFileVersion.write( 1.0f );

  // Create string dataset File Type
  HdfDataset dsFileType( file.id(), "/File Type", HdfDataType::createString() );
  dsFileType.write( "Xmdf" );

  // Create group TIMDEP NETCDF OUTPUT RESULTS
  HdfGroup groupTNOR = HdfGroup::create( file.id(), "/TIMDEP NETCDF OUTPUT RESULTS" );

  // Create attribute
  HdfAttribute attTNORGrouptype( groupTNOR.id(), "Grouptype", HdfDataType::createString() );
  // Write string value to attribute
  attTNORGrouptype.write( "Generic" );

  return appendGroup( file, dsGroup, groupTNOR );
}

bool MDAL::DriverFlo2D::appendGroup( HdfFile &file, MDAL::DatasetGroup *dsGroup, HdfGroup &groupTNOR )
{
  assert( dsGroup->dataLocation() == MDAL_DataLocation::DataOnFaces );

  HdfDataType dtMaxString = HdfDataType::createString();
  std::string dsGroupName = dsGroup->name();
  const size_t timesCount = dsGroup->datasets.size();
  const size_t facesCount = dsGroup->mesh()->facesCount();
  size_t valCount = facesCount;
  HdfDataspace dscValues;
  if ( dsGroup->isScalar() )
  {
    std::vector<hsize_t> dimsForScalarValues = { timesCount, facesCount };
    dscValues = HdfDataspace( dimsForScalarValues );
  }
  else
  {
    valCount *= 2;
    std::vector<hsize_t> dimsForVectorValues = { timesCount, facesCount, 2 };
    dscValues =  HdfDataspace( dimsForVectorValues );
  }

  std::vector<hsize_t> timesCountVec = {timesCount};
  HdfDataspace dscTimes( timesCountVec );

  std::vector<float> maximums( timesCount );
  std::vector<float> minimums( timesCount );
  std::vector<double> times( timesCount );
  std::vector<float> values( timesCount * valCount );

  // prepare data
  for ( size_t i = 0; i < dsGroup->datasets.size(); i++ )
  {
    const std::shared_ptr<Dataset> &dataset = dsGroup->datasets.at( i );
    std::vector<double> singleRowValues( valCount );

    if ( dsGroup->isScalar() )
    {
      dataset->scalarData( 0, facesCount, singleRowValues.data() );
    }
    else
    {
      dataset->vectorData( 0, facesCount, singleRowValues.data() );
    }

    for ( size_t j = 0; j < valCount; j++ )
    {
      double doubleValue = toFlo2DDouble( singleRowValues[j] );
      values[i * valCount + j] = static_cast<float>( doubleValue );
    }

    const Statistics st = dataset->statistics();
    maximums[i] = static_cast<float>( st.maximum );
    minimums[i] = static_cast<float>( st.minimum );
    times[i] = dataset->time( RelativeTimestamp::hours ) ;
  }

  // store data
  int i = 0;
  while ( file.pathExists( "/TIMDEP NETCDF OUTPUT RESULTS/" + dsGroupName ) )
  {
    dsGroupName = dsGroup->name() + "_" + std::to_string( i ); // make sure we have unique group name
  }
  HdfGroup group = HdfGroup::create( groupTNOR.id(), "/TIMDEP NETCDF OUTPUT RESULTS/" + dsGroupName );

  HdfAttribute attDataType( group.id(), "Data Type", H5T_NATIVE_INT );
  attDataType.write( 0 );

  HdfAttribute attDatasetCompression( group.id(), "DatasetCompression", H5T_NATIVE_INT );
  attDatasetCompression.write( -1 );

  /*
  HdfDataspace dscDatasetUnits( dimsSingle );
  HdfAttribute attDatasetUnits( group.id(), "DatasetUnits", true );
  attDatasetUnits.writeString( dscDatasetUnits.id(), "unknown" );
  */

  HdfAttribute attGrouptype( group.id(), "Grouptype", dtMaxString );
  if ( dsGroup->isScalar() )
    attGrouptype.write( "DATASET SCALAR" );
  else
    attGrouptype.write( "DATASET VECTOR" );

  HdfAttribute attTimeUnits( group.id(), "TimeUnits", dtMaxString );
  attTimeUnits.write( "Hours" );

  HdfDataset dsMaxs( file.id(), "/TIMDEP NETCDF OUTPUT RESULTS/" + dsGroupName + "/Maxs", H5T_NATIVE_FLOAT, timesCountVec );
  dsMaxs.write( maximums );

  HdfDataset dsMins( file.id(), "/TIMDEP NETCDF OUTPUT RESULTS/" + dsGroupName + "/Mins", H5T_NATIVE_FLOAT, timesCountVec );
  dsMins.write( minimums );

  HdfDataset dsTimes( file.id(), "/TIMDEP NETCDF OUTPUT RESULTS/" + dsGroupName + "/Times", H5T_NATIVE_DOUBLE, timesCountVec );
  dsTimes.write( times );

  HdfDataset dsValues( file.id(), "/TIMDEP NETCDF OUTPUT RESULTS/" + dsGroupName + "/Values", H5T_NATIVE_FLOAT, dscValues );
  dsValues.write( values );

  return false; //OK
}

bool MDAL::DriverFlo2D::persist( DatasetGroup *group )
{
  if ( !group || ( group->dataLocation() != MDAL_DataLocation::DataOnFaces ) )
  {
    MDAL::Log::error( MDAL_Status::Err_IncompatibleDataset, name(), "flo-2d can store only 2D face datasets" );
    return true;
  }

  try
  {
    // Return true on error
    if ( MDAL::fileExists( group->uri() ) )
    {
      // Add dataset to a existing file
      return addToHDF5File( group );
    }
    else
    {
      // Create new HDF5 file with Flow2D structure
      return saveNewHDF5File( group );
    }
  }
  catch ( MDAL_Status error )
  {
    MDAL::Log::error( error, name(), "error occurred" );
    return true;
  }
  catch ( MDAL::Error err )
  {
    MDAL::Log::error( err, name() );
    return true;
  }
}