/**
 * \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
 *
 */

#pragma once

#include <memory>
#include <vector>

#include "HydroMechanicsProcessData.h"
#include "LocalAssemblerInterface.h"
#include "MaterialLib/PhysicalConstant.h"
#include "MaterialLib/SolidModels/LinearElasticIsotropic.h"
#include "MathLib/KelvinVector.h"
#include "MathLib/LinAlg/Eigen/EigenMapTools.h"
#include "NumLib/DOF/DOFTableUtil.h"
#include "NumLib/Fem/InitShapeMatrices.h"
#include "NumLib/Fem/ShapeMatrixPolicy.h"
#include "ParameterLib/Parameter.h"
#include "ProcessLib/Deformation/BMatrixPolicy.h"
#include "ProcessLib/Deformation/LinearBMatrix.h"
#include "ProcessLib/LocalAssemblerTraits.h"
#include "ProcessLib/Utils/SetOrGetIntegrationPointData.h"

namespace ProcessLib
{
namespace HydroMechanics
{
namespace MPL = MaterialPropertyLib;

template <typename BMatricesType, typename ShapeMatrixTypeDisplacement,
          typename ShapeMatricesTypePressure, int DisplacementDim, int NPoints>
struct IntegrationPointData final
{
    explicit IntegrationPointData(
        MaterialLib::Solids::MechanicsBase<DisplacementDim> const&
            solid_material)
        : solid_material(solid_material),
          material_state_variables(
              solid_material.createMaterialStateVariables())
    {
    }

    typename ShapeMatrixTypeDisplacement::template MatrixType<
        DisplacementDim, NPoints * DisplacementDim>
        N_u_op; /**< for interpolation of the displacement vector, whereas N_u interpolates one component (scalar) */
    typename BMatricesType::KelvinVectorType sigma_eff, sigma_eff_prev;
    typename BMatricesType::KelvinVectorType eps, eps_prev;

    typename ShapeMatrixTypeDisplacement::NodalRowVectorType N_u;
    typename ShapeMatrixTypeDisplacement::GlobalDimNodalMatrixType dNdx_u;

    typename ShapeMatricesTypePressure::NodalRowVectorType N_p;
    typename ShapeMatricesTypePressure::GlobalDimNodalMatrixType dNdx_p;

    MaterialLib::Solids::MechanicsBase<DisplacementDim> const& solid_material;
    std::unique_ptr<typename MaterialLib::Solids::MechanicsBase<
        DisplacementDim>::MaterialStateVariables>
        material_state_variables;
    double integration_weight;

    void pushBackState()
    {
        eps_prev = eps;
        sigma_eff_prev = sigma_eff;
        material_state_variables->pushBackState();
    }

    template <typename DisplacementVectorType>
    typename BMatricesType::KelvinMatrixType updateConstitutiveRelation(
        MPL::VariableArray const& variable_array,
        double const t,
        ParameterLib::SpatialPosition const& x_position,
        double const dt,
        DisplacementVectorType const& /*u*/,
        double const T)
    {
        MaterialPropertyLib::VariableArray variable_array_prev;
        variable_array_prev[static_cast<int>(
                                MaterialPropertyLib::Variable::stress)]
            .emplace<MathLib::KelvinVector::KelvinVectorType<DisplacementDim>>(
                sigma_eff_prev);
        variable_array_prev[static_cast<int>(MaterialPropertyLib::Variable::
                                                 mechanical_strain)]
            .emplace<MathLib::KelvinVector::KelvinVectorType<DisplacementDim>>(
                eps_prev);
        variable_array_prev[static_cast<int>(
                                MaterialPropertyLib::Variable::temperature)]
            .emplace<double>(T);

        auto&& solution = solid_material.integrateStress(
            variable_array_prev, variable_array, t, x_position, dt,
            *material_state_variables);

        if (!solution)
        {
            OGS_FATAL("Computation of local constitutive relation failed.");
        }

        MathLib::KelvinVector::KelvinMatrixType<DisplacementDim> C;
        std::tie(sigma_eff, material_state_variables, C) = std::move(*solution);

        return C;
    }

    EIGEN_MAKE_ALIGNED_OPERATOR_NEW;
};

/// Used for the extrapolation of the integration point values. It is ordered
/// (and stored) by integration points.
template <typename ShapeMatrixType>
struct SecondaryData
{
    std::vector<ShapeMatrixType, Eigen::aligned_allocator<ShapeMatrixType>> N_u;
};

template <typename ShapeFunctionDisplacement, typename ShapeFunctionPressure,
          typename IntegrationMethod, int DisplacementDim>
class HydroMechanicsLocalAssembler
    : public LocalAssemblerInterface<DisplacementDim>
{
public:
    using ShapeMatricesTypeDisplacement =
        ShapeMatrixPolicyType<ShapeFunctionDisplacement, DisplacementDim>;

    // Types for pressure.
    using ShapeMatricesTypePressure =
        ShapeMatrixPolicyType<ShapeFunctionPressure, DisplacementDim>;

    static int const KelvinVectorSize =
        MathLib::KelvinVector::KelvinVectorDimensions<DisplacementDim>::value;
    using Invariants = MathLib::KelvinVector::Invariants<KelvinVectorSize>;

    using SymmetricTensor = Eigen::Matrix<double, KelvinVectorSize, 1>;

    HydroMechanicsLocalAssembler(HydroMechanicsLocalAssembler const&) = delete;
    HydroMechanicsLocalAssembler(HydroMechanicsLocalAssembler&&) = delete;

    HydroMechanicsLocalAssembler(
        MeshLib::Element const& e,
        std::size_t const /*local_matrix_size*/,
        bool const is_axially_symmetric,
        unsigned const integration_order,
        HydroMechanicsProcessData<DisplacementDim>& process_data);

    /// Returns number of read integration points.
    std::size_t setIPDataInitialConditions(
        std::string const& name,
        double const* values,
        int const integration_order) override;

    void assemble(double const /*t*/, double const /*dt*/,
                  std::vector<double> const& /*local_x*/,
                  std::vector<double> const& /*local_xdot*/,
                  std::vector<double>& /*local_M_data*/,
                  std::vector<double>& /*local_K_data*/,
                  std::vector<double>& /*local_rhs_data*/) override
    {
        OGS_FATAL(
            "HydroMechanicsLocalAssembler: assembly without jacobian is not "
            "implemented.");
    }

    void assembleWithJacobian(double const t, double const dt,
                              std::vector<double> const& local_x,
                              std::vector<double> const& local_xdot,
                              const double /*dxdot_dx*/, const double /*dx_dx*/,
                              std::vector<double>& /*local_M_data*/,
                              std::vector<double>& /*local_K_data*/,
                              std::vector<double>& local_rhs_data,
                              std::vector<double>& local_Jac_data) override;

    void assembleWithJacobianForStaggeredScheme(
        const double t, double const dt, Eigen::VectorXd const& local_x,
        Eigen::VectorXd const& local_xdot, const double dxdot_dx,
        const double dx_dx, int const process_id,
        std::vector<double>& local_M_data, std::vector<double>& local_K_data,
        std::vector<double>& local_b_data,
        std::vector<double>& local_Jac_data) override;

    void initializeConcrete() override
    {
        unsigned const n_integration_points =
            _integration_method.getNumberOfPoints();

        for (unsigned ip = 0; ip < n_integration_points; ip++)
        {
            _ip_data[ip].pushBackState();
        }
    }

    void postTimestepConcrete(Eigen::VectorXd const& /*local_x*/,
                              double const /*t*/,
                              double const /*dt*/) override
    {
        unsigned const n_integration_points =
            _integration_method.getNumberOfPoints();

        for (unsigned ip = 0; ip < n_integration_points; ip++)
        {
            _ip_data[ip].pushBackState();
        }
    }

    void computeSecondaryVariableConcrete(
        double const t, double const dt, Eigen::VectorXd const& local_xs,
        Eigen::VectorXd const& local_x_dot) override;

    void postNonLinearSolverConcrete(std::vector<double> const& local_x,
                                     std::vector<double> const& local_xdot,
                                     double const t, double const dt,
                                     bool const use_monolithic_scheme,
                                     int const process_id) override;

    void setInitialConditionsConcrete(std::vector<double> const& local_x,
                                      double const t,
                                      bool const use_monolithic_scheme,
                                      int const process_id) override;

    Eigen::Map<const Eigen::RowVectorXd> getShapeMatrix(
        const unsigned integration_point) const override
    {
        auto const& N_u = _secondary_data.N_u[integration_point];

        // assumes N is stored contiguously in memory
        return Eigen::Map<const Eigen::RowVectorXd>(N_u.data(), N_u.size());
    }

    std::size_t setSigma(double const* values);

    // TODO (naumov) This method is same as getIntPtSigma but for arguments and
    // the ordering of the cache_mat.
    // There should be only one.
    std::vector<double> getSigma() const override;

    std::size_t setEpsilon(double const* values);

    std::vector<double> getEpsilon() const override;

    std::vector<double> const& getIntPtDarcyVelocity(
        const double t,
        std::vector<GlobalVector*> const& x,
        std::vector<NumLib::LocalToGlobalIndexMap const*> const& dof_table,
        std::vector<double>& cache) const override;

    std::vector<double> const& getIntPtSigma(
        const double /*t*/,
        std::vector<GlobalVector*> const& /*x*/,
        std::vector<NumLib::LocalToGlobalIndexMap const*> const& /*dof_table*/,
        std::vector<double>& cache) const override
    {
        return ProcessLib::getIntegrationPointKelvinVectorData<DisplacementDim>(
            _ip_data, &IpData::sigma_eff, cache);
    }

    std::vector<double> const& getIntPtEpsilon(
        const double /*t*/,
        std::vector<GlobalVector*> const& /*x*/,
        std::vector<NumLib::LocalToGlobalIndexMap const*> const& /*dof_table*/,
        std::vector<double>& cache) const override
    {
        return ProcessLib::getIntegrationPointKelvinVectorData<DisplacementDim>(
            _ip_data, &IpData::eps, cache);
    }

private:

    /**
     * Assemble local matrices and vectors arise from the linearized discretized
     * weak form of the residual of the momentum balance equation,
     *      \f[
     *            \nabla (\sigma - \alpha_b p \mathrm{I}) = f
     *      \f]
     * where \f$ \sigma\f$ is the effective stress tensor, \f$p\f$ is the pore
     * pressure, \f$\alpha_b\f$ is the Biot constant, \f$\mathrm{I}\f$ is the
     * identity tensor, and \f$f\f$ is the body force.
     *
     * @param t               Time
     * @param dt              Time increment
     * @param local_x         Nodal values of \f$x\f$ of an element of all
     * coupled processes.
     * @param local_b_data    Right hand side vector of an element.
     * @param local_Jac_data  Element Jacobian matrix for the Newton-Raphson
     *                        method.
     */
    void assembleWithJacobianForDeformationEquations(
        const double t, double const dt, Eigen::VectorXd const& local_x,
        std::vector<double>& local_b_data, std::vector<double>& local_Jac_data);

    /**
     * Assemble local matrices and vectors arise from the linearized discretized
     * weak form of the residual of the mass balance equation of single phase
     * flow,
     *      \f[
     *          \alpha \cdot{p} - \nabla (K (\nabla p + \rho g \nabla z) +
     *          \alpha_b \nabla \cdot \dot{u}  = Q
     *      \f]
     * where \f$ alpha\f$ is a coefficient may depend on storage or the fluid
     * density change, \f$ \rho\f$ is the fluid density, \f$g\f$ is the
     * gravitational acceleration, \f$z\f$ is the vertical coordinate, \f$u\f$
     * is the displacement, and \f$Q\f$ is the source/sink term.
     *
     * @param t               Time
     * @param dt              Time increment
     * @param local_x         Nodal values of \f$x\f$ of an element  of all
     * coupled processes.
     * @param local_xdot      Nodal values of \f$\dot{x}\f$ of an element  of
     * all coupled processes.
     * @param local_b_data    Right hand side vector of an element.
     * @param local_Jac_data  Element Jacobian matrix for the Newton-Raphson
     *                        method.
     */
    void assembleWithJacobianForPressureEquations(
        const double t, double const dt, Eigen::VectorXd const& local_x,
        Eigen::VectorXd const& local_xdot, std::vector<double>& local_b_data,
        std::vector<double>& local_Jac_data);

    unsigned getNumberOfIntegrationPoints() const override;

    typename MaterialLib::Solids::MechanicsBase<
        DisplacementDim>::MaterialStateVariables const&
    getMaterialStateVariablesAt(unsigned integration_point) const override;

private:
    HydroMechanicsProcessData<DisplacementDim>& _process_data;

    using BMatricesType =
        BMatrixPolicyType<ShapeFunctionDisplacement, DisplacementDim>;
    using IpData =
        IntegrationPointData<BMatricesType, ShapeMatricesTypeDisplacement,
                             ShapeMatricesTypePressure, DisplacementDim,
                             ShapeFunctionDisplacement::NPOINTS>;
    std::vector<IpData, Eigen::aligned_allocator<IpData>> _ip_data;

    IntegrationMethod _integration_method;
    MeshLib::Element const& _element;
    bool const _is_axially_symmetric;
    SecondaryData<
        typename ShapeMatricesTypeDisplacement::ShapeMatrices::ShapeType>
        _secondary_data;

    static const int pressure_index = 0;
    static const int pressure_size = ShapeFunctionPressure::NPOINTS;
    static const int displacement_index = ShapeFunctionPressure::NPOINTS;
    static const int displacement_size =
        ShapeFunctionDisplacement::NPOINTS * DisplacementDim;
};

}  // namespace HydroMechanics
}  // namespace ProcessLib

#include "HydroMechanicsFEM-impl.h"