/**
 * \file
 * \copyright
 * Copyright (c) 2012-2021, 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 "SmallDeformationProcess.h"

#include <cassert>
#include <nlohmann/json.hpp>

#include "ProcessLib/Deformation/SolidMaterialInternalToSecondaryVariables.h"
#include "ProcessLib/Output/IntegrationPointWriter.h"
#include "ProcessLib/Process.h"
#include "ProcessLib/SmallDeformation/CreateLocalAssemblers.h"
#include "SmallDeformationFEM.h"

namespace ProcessLib
{
namespace SmallDeformation
{
template <int DisplacementDim>
SmallDeformationProcess<DisplacementDim>::SmallDeformationProcess(
    std::string name,
    MeshLib::Mesh& mesh,
    std::unique_ptr<ProcessLib::AbstractJacobianAssembler>&& jacobian_assembler,
    std::vector<std::unique_ptr<ParameterLib::ParameterBase>> const& parameters,
    unsigned const integration_order,
    std::vector<std::vector<std::reference_wrapper<ProcessVariable>>>&&
        process_variables,
    SmallDeformationProcessData<DisplacementDim>&& process_data,
    SecondaryVariableCollection&& secondary_variables)
    : Process(std::move(name), mesh, std::move(jacobian_assembler), parameters,
              integration_order, std::move(process_variables),
              std::move(secondary_variables)),
      _process_data(std::move(process_data))
{
    _nodal_forces = MeshLib::getOrCreateMeshProperty<double>(
        mesh, "NodalForces", MeshLib::MeshItemType::Node, DisplacementDim);

    _material_forces = MeshLib::getOrCreateMeshProperty<double>(
        mesh, "MaterialForces", MeshLib::MeshItemType::Node, DisplacementDim);

    _process_data.principal_stress_vector[0] =
        MeshLib::getOrCreateMeshProperty<double>(
            const_cast<MeshLib::Mesh&>(mesh), "principal_stress_vector_1",
            MeshLib::MeshItemType::Cell, 3);

    _process_data.principal_stress_vector[1] =
        MeshLib::getOrCreateMeshProperty<double>(
            const_cast<MeshLib::Mesh&>(mesh), "principal_stress_vector_2",
            MeshLib::MeshItemType::Cell, 3);

    _process_data.principal_stress_vector[2] =
        MeshLib::getOrCreateMeshProperty<double>(
            const_cast<MeshLib::Mesh&>(mesh), "principal_stress_vector_3",
            MeshLib::MeshItemType::Cell, 3);

    _process_data.principal_stress_values =
        MeshLib::getOrCreateMeshProperty<double>(
            const_cast<MeshLib::Mesh&>(mesh), "principal_stress_values",
            MeshLib::MeshItemType::Cell, 3);

    // TODO (naumov) remove ip suffix. Probably needs modification of the mesh
    // properties, s.t. there is no "overlapping" with cell/point data.
    // See getOrCreateMeshProperty.
    _integration_point_writer.emplace_back(
        std::make_unique<IntegrationPointWriter>(
            "sigma_ip",
            static_cast<int>(mesh.getDimension() == 2 ? 4 : 6) /*n components*/,
            integration_order, [this]() {
                // Result containing integration point data for each local
                // assembler.
                std::vector<std::vector<double>> result;
                result.resize(_local_assemblers.size());

                for (std::size_t i = 0; i < _local_assemblers.size(); ++i)
                {
                    auto const& local_asm = *_local_assemblers[i];

                    result[i] = local_asm.getSigma();
                }

                return result;
            }));
}

template <int DisplacementDim>
bool SmallDeformationProcess<DisplacementDim>::isLinear() const
{
    return false;
}

template <int DisplacementDim>
void SmallDeformationProcess<DisplacementDim>::initializeConcreteProcess(
    NumLib::LocalToGlobalIndexMap const& dof_table,
    MeshLib::Mesh const& mesh,
    unsigned const integration_order)
{
    using nlohmann::json;

    ProcessLib::SmallDeformation::createLocalAssemblers<
        DisplacementDim, SmallDeformationLocalAssembler>(
        mesh.getElements(), dof_table, _local_assemblers,
        mesh.isAxiallySymmetric(), integration_order, _process_data);

    auto add_secondary_variable = [&](std::string const& name,
                                      int const num_components,
                                      auto get_ip_values_function) {
        _secondary_variables.addSecondaryVariable(
            name,
            makeExtrapolator(num_components, getExtrapolator(),
                             _local_assemblers,
                             std::move(get_ip_values_function)));
    };

    add_secondary_variable("free_energy_density",
                           1,
                           &LocalAssemblerInterface::getIntPtFreeEnergyDensity);

    add_secondary_variable("sigma",
                           MathLib::KelvinVector::KelvinVectorType<
                               DisplacementDim>::RowsAtCompileTime,
                           &LocalAssemblerInterface::getIntPtSigma);

    add_secondary_variable("epsilon",
                           MathLib::KelvinVector::KelvinVectorType<
                               DisplacementDim>::RowsAtCompileTime,
                           &LocalAssemblerInterface::getIntPtEpsilon);

    //
    // enable output of internal variables defined by material models
    //
    ProcessLib::Deformation::solidMaterialInternalToSecondaryVariables<
        LocalAssemblerInterface>(_process_data.solid_materials,
                                 add_secondary_variable);

    // Set initial conditions for integration point data.
    for (auto const& ip_writer : _integration_point_writer)
    {
        // Find the mesh property with integration point writer's name.
        auto const& name = ip_writer->name();
        if (!mesh.getProperties().existsPropertyVector<double>(name))
        {
            continue;
        }
        auto const& mesh_property =
            *mesh.getProperties().template getPropertyVector<double>(name);

        // The mesh property must be defined on integration points.
        if (mesh_property.getMeshItemType() !=
            MeshLib::MeshItemType::IntegrationPoint)
        {
            continue;
        }

        auto const ip_meta_data = getIntegrationPointMetaData(mesh, name);

        // Check the number of components.
        if (ip_meta_data.n_components !=
            mesh_property.getNumberOfGlobalComponents())
        {
            OGS_FATAL(
                "Different number of components in meta data ({:d}) than in "
                "the integration point field data for '{:s}': {:d}.",
                ip_meta_data.n_components, name,
                mesh_property.getNumberOfGlobalComponents());
        }

        // Now we have a properly named vtk's field data array and the
        // corresponding meta data.
        std::size_t position = 0;
        for (auto& local_asm : _local_assemblers)
        {
            std::size_t const integration_points_read =
                local_asm->setIPDataInitialConditions(
                    name, &mesh_property[position],
                    ip_meta_data.integration_order);
            if (integration_points_read == 0)
            {
                OGS_FATAL(
                    "No integration points read in the integration point "
                    "initial conditions set function.");
            }
            position += integration_points_read * ip_meta_data.n_components;
        }
    }

    // Initialize local assemblers after all variables have been set.
    GlobalExecutor::executeMemberOnDereferenced(
        &LocalAssemblerInterface::initialize, _local_assemblers,
        *_local_to_global_index_map);
}

template <int DisplacementDim>
void SmallDeformationProcess<DisplacementDim>::assembleConcreteProcess(
    const double t, double const dt, std::vector<GlobalVector*> const& x,
    std::vector<GlobalVector*> const& xdot, int const process_id,
    GlobalMatrix& M, GlobalMatrix& K, GlobalVector& b)
{
    DBUG("Assemble SmallDeformationProcess.");

    ProcessLib::ProcessVariable const& pv = getProcessVariables(process_id)[0];

    std::vector<std::reference_wrapper<NumLib::LocalToGlobalIndexMap>>
        dof_table = {std::ref(*_local_to_global_index_map)};
    // Call global assembler for each local assembly item.
    GlobalExecutor::executeSelectedMemberDereferenced(
        _global_assembler, &VectorMatrixAssembler::assemble, _local_assemblers,
        pv.getActiveElementIDs(), dof_table, t, dt, x, xdot, process_id, M, K,
        b);
}

template <int DisplacementDim>
void SmallDeformationProcess<DisplacementDim>::
    assembleWithJacobianConcreteProcess(
        const double t, double const dt, std::vector<GlobalVector*> const& x,
        std::vector<GlobalVector*> const& xdot, const double dxdot_dx,
        const double dx_dx, int const process_id, GlobalMatrix& M,
        GlobalMatrix& K, GlobalVector& b, GlobalMatrix& Jac)
{
    DBUG("AssembleWithJacobian SmallDeformationProcess.");

    ProcessLib::ProcessVariable const& pv = getProcessVariables(process_id)[0];

    std::vector<std::reference_wrapper<NumLib::LocalToGlobalIndexMap>>
        dof_table = {std::ref(*_local_to_global_index_map)};
    // Call global assembler for each local assembly item.
    GlobalExecutor::executeSelectedMemberDereferenced(
        _global_assembler, &VectorMatrixAssembler::assembleWithJacobian,
        _local_assemblers, pv.getActiveElementIDs(), dof_table, t, dt, x, xdot,
        dxdot_dx, dx_dx, process_id, M, K, b, Jac);

    transformVariableFromGlobalVector(b, 0, *_local_to_global_index_map,
                                      *_nodal_forces, std::negate<double>());
}

template <int DisplacementDim>
void SmallDeformationProcess<DisplacementDim>::postTimestepConcreteProcess(
    std::vector<GlobalVector*> const& x, const double t, const double dt,
    int const process_id)
{
    DBUG("PostTimestep SmallDeformationProcess.");
    std::vector<NumLib::LocalToGlobalIndexMap const*> dof_tables;
    dof_tables.reserve(x.size());
    std::generate_n(std::back_inserter(dof_tables), x.size(),
                    [&]() { return _local_to_global_index_map.get(); });

    ProcessLib::ProcessVariable const& pv = getProcessVariables(process_id)[0];
    GlobalExecutor::executeSelectedMemberOnDereferenced(
        &LocalAssemblerInterface::postTimestep, _local_assemblers,
        pv.getActiveElementIDs(), dof_tables, x, t, dt);

    std::unique_ptr<GlobalVector> material_forces;
    ProcessLib::SmallDeformation::writeMaterialForces(
        material_forces, _local_assemblers, *_local_to_global_index_map,
        *x[process_id]);

    material_forces->copyValues(*_material_forces);
}

template <int DisplacementDim>
void SmallDeformationProcess<DisplacementDim>::computeSecondaryVariableConcrete(
    double const t, double const dt, std::vector<GlobalVector*> const& x,
    GlobalVector const& x_dot, const int process_id)
{
    DBUG("Compute the secondary variables for SmallDeformationProcess.");
    std::vector<NumLib::LocalToGlobalIndexMap const*> dof_tables;
    dof_tables.reserve(x.size());
    std::generate_n(std::back_inserter(dof_tables), x.size(),
                    [&]() { return _local_to_global_index_map.get(); });

    ProcessLib::ProcessVariable const& pv = getProcessVariables(process_id)[0];
    GlobalExecutor::executeSelectedMemberOnDereferenced(
        &LocalAssemblerInterface::computeSecondaryVariable, _local_assemblers,
        pv.getActiveElementIDs(), dof_tables, t, dt, x, x_dot, process_id);
}
template class SmallDeformationProcess<2>;
template class SmallDeformationProcess<3>;

}  // namespace SmallDeformation
}  // namespace ProcessLib