ProjectData.cpp

/**
 * \author Karsten Rink
 * \date   2010-08-25
 * \brief  Implementation of the project data class.
 *
 * \copyright
 * Copyright (c) 2012-2018, OpenGeoSys Community (http://www.opengeosys.org)
 *            Distributed under a Modified BSD License.
 *              See accompanying file LICENSE.txt or
 *              http://www.opengeosys.org/project/license
 *
 */

#include "ProjectData.h"

#include <algorithm>
#include <set>

#include <logog/include/logog.hpp>

#ifdef OGS_USE_PYTHON
#include <pybind11/eval.h>
#endif

#include "BaseLib/Algorithm.h"
#include "BaseLib/FileTools.h"

#include "GeoLib/GEOObjects.h"
#include "MathLib/Curve/CreatePiecewiseLinearCurve.h"
#include "MeshGeoToolsLib/ConstructMeshesFromGeometries.h"
#include "MeshGeoToolsLib/CreateSearchLength.h"
#include "MeshGeoToolsLib/SearchLength.h"
#include "MeshLib/Mesh.h"

#include "NumLib/ODESolver/ConvergenceCriterion.h"
#include "ProcessLib/CreateJacobianAssembler.h"

// FileIO
#include "GeoLib/IO/XmlIO/Boost/BoostXmlGmlInterface.h"
#include "MeshLib/IO/readMeshFromFile.h"

#include "ProcessLib/UncoupledProcessesTimeLoop.h"

#ifdef OGS_BUILD_PROCESS_COMPONENTTRANSPORT
#include "ProcessLib/ComponentTransport/CreateComponentTransportProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_GROUNDWATERFLOW
#include "ProcessLib/GroundwaterFlow/CreateGroundwaterFlowProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_HT
#include "ProcessLib/HT/CreateHTProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_HEATCONDUCTION
#include "ProcessLib/HeatConduction/CreateHeatConductionProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_HYDROMECHANICS
#include "ProcessLib/HydroMechanics/CreateHydroMechanicsProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_LIE
#include "ProcessLib/LIE/HydroMechanics/CreateHydroMechanicsProcess.h"
#include "ProcessLib/LIE/SmallDeformation/CreateSmallDeformationProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_LIQUIDFLOW
#include "ProcessLib/LiquidFlow/CreateLiquidFlowProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_PHASEFIELD
#include "ProcessLib/PhaseField/CreatePhaseFieldProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_RICHARDSCOMPONENTTRANSPORT
#include "ProcessLib/RichardsComponentTransport/CreateRichardsComponentTransportProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_RICHARDSFLOW
#include "ProcessLib/RichardsFlow/CreateRichardsFlowProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_RICHARDSMECHANICS
#include "ProcessLib/RichardsMechanics/CreateRichardsMechanicsProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_SMALLDEFORMATION
#include "ProcessLib/SmallDeformation/CreateSmallDeformationProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_TES
#include "ProcessLib/TES/CreateTESProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_THERMALTWOPHASEFLOWWITHPP
#include "ProcessLib/ThermalTwoPhaseFlowWithPP/CreateThermalTwoPhaseFlowWithPPProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_THERMOMECHANICALPHASEFIELD
#include "ProcessLib/ThermoMechanicalPhaseField/CreateThermoMechanicalPhaseFieldProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_THERMOMECHANICS
#include "ProcessLib/ThermoMechanics/CreateThermoMechanicsProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_TWOPHASEFLOWWITHPP
#include "ProcessLib/TwoPhaseFlowWithPP/CreateTwoPhaseFlowWithPPProcess.h"
#endif
#ifdef OGS_BUILD_PROCESS_TWOPHASEFLOWWITHPRHO
#include "ProcessLib/TwoPhaseFlowWithPrho/CreateTwoPhaseFlowWithPrhoProcess.h"
#endif

namespace
{
void readGeometry(std::string const& fname, GeoLib::GEOObjects& geo_objects)
{
    DBUG("Reading geometry file \'%s\'.", fname.c_str());
    GeoLib::IO::BoostXmlGmlInterface gml_reader(geo_objects);
    gml_reader.readFile(fname);
}

std::unique_ptr<MeshLib::Mesh> readSingleMesh(
    BaseLib::ConfigTree const& mesh_config_parameter,
    std::string const& project_directory)
{
    std::string const mesh_file = BaseLib::copyPathToFileName(
        mesh_config_parameter.getValue<std::string>(), project_directory);

    auto mesh = std::unique_ptr<MeshLib::Mesh>(
        MeshLib::IO::readMeshFromFile(mesh_file));
    if (!mesh)
    {
        OGS_FATAL("Could not read mesh from \'%s\' file. No mesh added.",
                  mesh_file.c_str());
    }

    if (auto const axially_symmetric =
            //! \ogs_file_attr{prj__mesh__axially_symmetric}
        mesh_config_parameter.getConfigAttributeOptional<bool>(
            "axially_symmetric"))
    {
        mesh->setAxiallySymmetric(*axially_symmetric);
    }

    return mesh;
}

std::vector<std::unique_ptr<MeshLib::Mesh>> readMeshes(
    BaseLib::ConfigTree const& config, std::string const& project_directory)
{
    std::vector<std::unique_ptr<MeshLib::Mesh>> meshes;

    meshes.push_back(
        //! \ogs_file_param{prj__mesh}
        readSingleMesh(config.getConfigParameter("mesh"), project_directory));

    std::string const geometry_file = BaseLib::copyPathToFileName(
        //! \ogs_file_param{prj__geometry}
        config.getConfigParameter<std::string>("geometry"),
        project_directory);
    GeoLib::GEOObjects geoObjects;
    readGeometry(geometry_file, geoObjects);

    std::unique_ptr<MeshGeoToolsLib::SearchLength> search_length_algorithm =
        MeshGeoToolsLib::createSearchLengthAlgorithm(config, *meshes[0]);
    auto additional_meshes =
        MeshGeoToolsLib::constructAdditionalMeshesFromGeoObjects(
            geoObjects, *meshes[0], std::move(search_length_algorithm));

    std::move(begin(additional_meshes), end(additional_meshes),
              std::back_inserter(meshes));

    return meshes;
}
}  // namespace

ProjectData::ProjectData() = default;

ProjectData::ProjectData(BaseLib::ConfigTree const& project_config,
                         std::string const& project_directory,
                         std::string const& output_directory)
{
    _mesh_vec = readMeshes(project_config, project_directory);

    if (auto const python_script =
            //! \ogs_file_param{prj__python_script}
        project_config.getConfigParameterOptional<std::string>("python_script"))
    {
#ifdef OGS_USE_PYTHON
        namespace py = pybind11;
        auto const script_path =
            BaseLib::copyPathToFileName(*python_script, project_directory);

        // Evaluate in scope of main module
        py::object scope = py::module::import("__main__").attr("__dict__");
        py::eval_file(script_path, scope);
#else
        OGS_FATAL("OpenGeoSys has not been built with Python support.");
#endif  // OGS_USE_PYTHON
    }

    //! \ogs_file_param{prj__curves}
    parseCurves(project_config.getConfigSubtreeOptional("curves"));

    //! \ogs_file_param{prj__parameters}
    parseParameters(project_config.getConfigSubtree("parameters"));

    //! \ogs_file_param{prj__process_variables}
    parseProcessVariables(project_config.getConfigSubtree("process_variables"));

    //! \ogs_file_param{prj__processes}
    parseProcesses(project_config.getConfigSubtree("processes"),
                   project_directory, output_directory);

    //! \ogs_file_param{prj__linear_solvers}
    parseLinearSolvers(project_config.getConfigSubtree("linear_solvers"));

    //! \ogs_file_param{prj__nonlinear_solvers}
    parseNonlinearSolvers(project_config.getConfigSubtree("nonlinear_solvers"));

    //! \ogs_file_param{prj__time_loop}
    parseTimeLoop(project_config.getConfigSubtree("time_loop"),
                  output_directory);
}

void ProjectData::parseProcessVariables(
    BaseLib::ConfigTree const& process_variables_config)
{
    DBUG("Parse process variables:");

    if (_mesh_vec.empty() || _mesh_vec[0] == nullptr)
    {
        ERR("A mesh is required to define process variables.");
        return;
    }

    std::set<std::string> names;

    for (auto var_config
         //! \ogs_file_param{prj__process_variables__process_variable}
         : process_variables_config.getConfigSubtreeList("process_variable"))
    {
        auto pv =
            ProcessLib::ProcessVariable{var_config, _mesh_vec, _parameters};
        if (!names.insert(pv.getName()).second)
            OGS_FATAL("A process variable with name `%s' already exists.",
                      pv.getName().c_str());

        _process_variables.push_back(std::move(pv));
    }
}

void ProjectData::parseParameters(BaseLib::ConfigTree const& parameters_config)
{
    using namespace ProcessLib;

    std::set<std::string> names;

    DBUG("Reading parameters:");
    for (auto parameter_config :
         //! \ogs_file_param{prj__parameters__parameter}
         parameters_config.getConfigSubtreeList("parameter"))
    {
        auto p =
            ProcessLib::createParameter(parameter_config, _mesh_vec, _curves);
        if (!names.insert(p->name).second)
            OGS_FATAL("A parameter with name `%s' already exists.",
                      p->name.c_str());

        _parameters.push_back(std::move(p));
    }

    for (auto& parameter : _parameters)
        parameter->initialize(_parameters);
}

void ProjectData::parseProcesses(BaseLib::ConfigTree const& processes_config,
                                 std::string const& project_directory,
                                 std::string const& output_directory)
{
    (void)project_directory; // to avoid compilation warning
    (void)output_directory; // to avoid compilation warning

    DBUG("Reading processes:");
    //! \ogs_file_param{prj__processes__process}
    for (auto process_config : processes_config.getConfigSubtreeList("process"))
    {
        auto const type =
            //! \ogs_file_param{prj__processes__process__type}
            process_config.peekConfigParameter<std::string>("type");

        auto const name =
            //! \ogs_file_param{prj__processes__process__name}
            process_config.getConfigParameter<std::string>("name");

        auto const integration_order =
            //! \ogs_file_param{prj__processes__process__integration_order}
            process_config.getConfigParameter<int>("integration_order");

        std::unique_ptr<ProcessLib::Process> process;

        auto jacobian_assembler = ProcessLib::createJacobianAssembler(
            //! \ogs_file_param{prj__processes__process__jacobian_assembler}
            process_config.getConfigSubtreeOptional("jacobian_assembler"));

#ifdef OGS_BUILD_PROCESS_GROUNDWATERFLOW
        if (type == "GROUNDWATER_FLOW")
        {
            // The existence check of the in the configuration referenced
            // process variables is checked in the physical process.
            // TODO at the moment we have only one mesh, later there can be
            // several meshes. Then we have to assign the referenced mesh
            // here.
            process = ProcessLib::GroundwaterFlow::createGroundwaterFlowProcess(
                *_mesh_vec[0], std::move(jacobian_assembler),
                _process_variables, _parameters, integration_order,
                process_config, project_directory, output_directory);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_LIQUIDFLOW
            if (type == "LIQUID_FLOW")
        {
            process = ProcessLib::LiquidFlow::createLiquidFlowProcess(
                *_mesh_vec[0], std::move(jacobian_assembler),
                _process_variables, _parameters, integration_order,
                process_config);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_TES
            if (type == "TES")
        {
            process = ProcessLib::TES::createTESProcess(
                *_mesh_vec[0], std::move(jacobian_assembler),
                _process_variables, _parameters, integration_order,
                process_config);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_HEATCONDUCTION
            if (type == "HEAT_CONDUCTION")
        {
            process = ProcessLib::HeatConduction::createHeatConductionProcess(
                *_mesh_vec[0], std::move(jacobian_assembler),
                _process_variables, _parameters, integration_order,
                process_config);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_HYDROMECHANICS
            if (type == "HYDRO_MECHANICS")
        {
            //! \ogs_file_param{prj__processes__process__HYDRO_MECHANICS__dimension}
            switch (process_config.getConfigParameter<int>("dimension"))
            {
                case 2:
                    process =
                        ProcessLib::HydroMechanics::createHydroMechanicsProcess<
                            2>(*_mesh_vec[0], std::move(jacobian_assembler),
                               _process_variables, _parameters,
                               integration_order, process_config);
                    break;
                case 3:
                    process =
                        ProcessLib::HydroMechanics::createHydroMechanicsProcess<
                            3>(*_mesh_vec[0], std::move(jacobian_assembler),
                               _process_variables, _parameters,
                               integration_order, process_config);
                    break;
                default:
                    OGS_FATAL(
                        "HYDRO_MECHANICS process does not support given "
                        "dimension");
            }
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_LIE
            if (type == "HYDRO_MECHANICS_WITH_LIE")
        {
            //! \ogs_file_param{prj__processes__process__HYDRO_MECHANICS_WITH_LIE__dimension}
            switch (process_config.getConfigParameter<int>("dimension"))
            {
                case 2:
                    process = ProcessLib::LIE::HydroMechanics::
                        createHydroMechanicsProcess<2>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                case 3:
                    process = ProcessLib::LIE::HydroMechanics::
                        createHydroMechanicsProcess<3>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                default:
                    OGS_FATAL(
                        "HYDRO_MECHANICS_WITH_LIE process does not support "
                        "given dimension");
            }
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_HT
            if (type == "HT")
        {
            process = ProcessLib::HT::createHTProcess(
                *_mesh_vec[0], std::move(jacobian_assembler),
                _process_variables, _parameters, integration_order,
                process_config, project_directory, output_directory);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_COMPONENTTRANSPORT
            if (type == "ComponentTransport")
        {
            process =
                ProcessLib::ComponentTransport::createComponentTransportProcess(
                    *_mesh_vec[0], std::move(jacobian_assembler),
                    _process_variables, _parameters, integration_order,
                    process_config);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_PHASEFIELD
            if (type == "PHASE_FIELD")
        {
            switch (_mesh_vec[0]->getDimension())
            {
                case 2:
                    process =
                        ProcessLib::PhaseField::createPhaseFieldProcess<
                            2>(*_mesh_vec[0], std::move(jacobian_assembler),
                               _process_variables, _parameters,
                               integration_order, process_config);
                    break;
                case 3:
                    process =
                        ProcessLib::PhaseField::createPhaseFieldProcess<
                            3>(*_mesh_vec[0], std::move(jacobian_assembler),
                               _process_variables, _parameters,
                               integration_order, process_config);
                    break;
            }
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_RICHARDSCOMPONENTTRANSPORT
            if (type == "RichardsComponentTransport")
        {
            process = ProcessLib::RichardsComponentTransport::
                createRichardsComponentTransportProcess(
                    *_mesh_vec[0], std::move(jacobian_assembler),
                    _process_variables, _parameters, integration_order,
                    process_config);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_SMALLDEFORMATION
            if (type == "SMALL_DEFORMATION")
        {
            switch (_mesh_vec[0]->getDimension())
            {
                case 2:
                    process = ProcessLib::SmallDeformation::
                        createSmallDeformationProcess<2>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                case 3:
                    process = ProcessLib::SmallDeformation::
                        createSmallDeformationProcess<3>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                default:
                    OGS_FATAL(
                        "SMALL_DEFORMATION process does not support "
                        "given dimension");
            }
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_LIE
            if (type == "SMALL_DEFORMATION_WITH_LIE")
        {
            //! \ogs_file_param{prj__processes__process__SMALL_DEFORMATION_WITH_LIE__dimension}
            switch (process_config.getConfigParameter<int>("dimension"))
            {
                case 2:
                    process = ProcessLib::LIE::SmallDeformation::
                        createSmallDeformationProcess<2>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                case 3:
                    process = ProcessLib::LIE::SmallDeformation::
                        createSmallDeformationProcess<3>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                default:
                    OGS_FATAL(
                        "SMALL_DEFORMATION_WITH_LIE process does not support "
                        "given dimension");
            }
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_THERMOMECHANICALPHASEFIELD
            if (type == "THERMO_MECHANICAL_PHASE_FIELD")
        {
            switch (_mesh_vec[0]->getDimension())
            {
                case 2:
                    process = ProcessLib::ThermoMechanicalPhaseField::
                        createThermoMechanicalPhaseFieldProcess<2>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                case 3:
                    process = ProcessLib::ThermoMechanicalPhaseField::
                        createThermoMechanicalPhaseFieldProcess<3>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
            }
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_THERMOMECHANICS
            if (type == "THERMO_MECHANICS")
        {
            switch (_mesh_vec[0]->getDimension())
            {
                case 2:
                    process = ProcessLib::ThermoMechanics::
                        createThermoMechanicsProcess<2>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                case 3:
                    process = ProcessLib::ThermoMechanics::
                        createThermoMechanicsProcess<3>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
            }
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_RICHARDSFLOW
            if (type == "RICHARDS_FLOW")
        {
            process = ProcessLib::RichardsFlow::createRichardsFlowProcess(
                *_mesh_vec[0], std::move(jacobian_assembler),
                _process_variables, _parameters, integration_order,
                process_config, _curves);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_RICHARDSMECHANICS
            if (type == "RICHARDS_MECHANICS")
        {
            //! \ogs_file_param{prj__processes__process__RICHARDS_MECHANICS__dimension}
            switch (process_config.getConfigParameter<int>("dimension"))
            {
                case 2:
                    process = ProcessLib::RichardsMechanics::
                        createRichardsMechanicsProcess<2>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
                case 3:
                    process = ProcessLib::RichardsMechanics::
                        createRichardsMechanicsProcess<3>(
                            *_mesh_vec[0], std::move(jacobian_assembler),
                            _process_variables, _parameters, integration_order,
                            process_config);
                    break;
            }
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_TWOPHASEFLOWWITHPP
            if (type == "TWOPHASE_FLOW_PP")
        {
            process =
                ProcessLib::TwoPhaseFlowWithPP::createTwoPhaseFlowWithPPProcess(
                    *_mesh_vec[0], std::move(jacobian_assembler),
                    _process_variables, _parameters, integration_order,
                    process_config, _curves);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_TWOPHASEFLOWWITHPRHO
            if (type == "TWOPHASE_FLOW_PRHO")
        {
            process = ProcessLib::TwoPhaseFlowWithPrho::
                createTwoPhaseFlowWithPrhoProcess(
                    *_mesh_vec[0], std::move(jacobian_assembler),
                    _process_variables, _parameters, integration_order,
                    process_config, _curves);
        }
        else
#endif
#ifdef OGS_BUILD_PROCESS_THERMALTWOPHASEFLOWWITHPP
            if (type == "THERMAL_TWOPHASE_WITH_PP")
        {
            process = ProcessLib::ThermalTwoPhaseFlowWithPP::
                createThermalTwoPhaseFlowWithPPProcess(
                    *_mesh_vec[0], std::move(jacobian_assembler),
                    _process_variables, _parameters, integration_order,
                    process_config, _curves);
        }
        else
#endif
        {
            OGS_FATAL("Unknown process type: %s", type.c_str());
        }

        BaseLib::insertIfKeyUniqueElseError(_processes,
                                            name,
                                            std::move(process),
                                            "The process name is not unique");
    }
}

void ProjectData::parseTimeLoop(BaseLib::ConfigTree const& config,
                                std::string const& output_directory)
{
    DBUG("Reading time loop configuration.");

    _time_loop = ProcessLib::createUncoupledProcessesTimeLoop(
        config, output_directory, _processes, _nonlinear_solvers);

    if (!_time_loop)
    {
        OGS_FATAL("Initialization of time loop failed.");
    }
}

void ProjectData::parseLinearSolvers(BaseLib::ConfigTree const& config)
{
    DBUG("Reading linear solver configuration.");

    //! \ogs_file_param{prj__linear_solvers__linear_solver}
    for (auto conf : config.getConfigSubtreeList("linear_solver"))
    {
        //! \ogs_file_param{prj__linear_solvers__linear_solver__name}
        auto const name = conf.getConfigParameter<std::string>("name");
        BaseLib::insertIfKeyUniqueElseError(
            _linear_solvers,
            name,
            std::make_unique<GlobalLinearSolver>("", &conf),
            "The linear solver name is not unique");
    }
}

void ProjectData::parseNonlinearSolvers(BaseLib::ConfigTree const& config)
{
    DBUG("Reading linear solver configuration.");

    //! \ogs_file_param{prj__nonlinear_solvers__nonlinear_solver}
    for (auto conf : config.getConfigSubtreeList("nonlinear_solver"))
    {
        auto const ls_name =
            //! \ogs_file_param{prj__nonlinear_solvers__nonlinear_solver__linear_solver}
            conf.getConfigParameter<std::string>("linear_solver");
        auto& linear_solver = BaseLib::getOrError(
            _linear_solvers, ls_name,
            "A linear solver with the given name does not exist.");

        //! \ogs_file_param{prj__nonlinear_solvers__nonlinear_solver__name}
        auto const name = conf.getConfigParameter<std::string>("name");
        BaseLib::insertIfKeyUniqueElseError(
            _nonlinear_solvers,
            name,
            NumLib::createNonlinearSolver(*linear_solver, conf).first,
            "The nonlinear solver name is not unique");
    }
}

void ProjectData::parseCurves(
    boost::optional<BaseLib::ConfigTree> const& config)
{
    if (!config)
        return;

    DBUG("Reading curves configuration.");

    //! \ogs_file_param{prj__curves__curve}
    for (auto conf : config->getConfigSubtreeList("curve"))
    {
        //! \ogs_file_param{prj__curves__curve__name}
        auto const name = conf.getConfigParameter<std::string>("name");
        BaseLib::insertIfKeyUniqueElseError(
            _curves,
            name,
            MathLib::createPiecewiseLinearCurve<
                MathLib::PiecewiseLinearInterpolation>(conf),
            "The curve name is not unique.");
    }
}