/*
  Copyright 2017 SINTEF Digital, Mathematics and Cybernetics.
  Copyright 2017 Statoil ASA.

  This file is part of the Open Porous Media project (OPM).

  OPM 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 3 of the License, or
  (at your option) any later version.

  OPM is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
*/


#ifndef OPM_MULTISEGMENTWELL_EVAL_HEADER_INCLUDED
#define OPM_MULTISEGMENTWELL_EVAL_HEADER_INCLUDED

#include <opm/simulators/wells/MultisegmentWellGeneric.hpp>

#include <opm/material/densead/Evaluation.hpp>

#include <opm/parser/eclipse/EclipseState/Schedule/Well/Well.hpp>

#include <dune/common/fmatrix.hh>
#include <dune/common/fvector.hh>
#include <dune/istl/bcrsmatrix.hh>
#include <dune/istl/bvector.hh>
#include <dune/istl/umfpack.hh>

#include <array>
#include <memory>

namespace Opm
{

class ConvergenceReport;
class GroupState;
class Schedule;
class WellContributions;
template<class FluidSystem, class Indices, class Scalar> class WellInterfaceIndices;
class WellState;

template<typename FluidSystem, typename Indices, typename Scalar>
class MultisegmentWellEval : public MultisegmentWellGeneric<Scalar>
{
public:
#if HAVE_CUDA || HAVE_OPENCL
        /// add the contribution (C, D, B matrices) of this Well to the WellContributions object
        void addWellContribution(WellContributions& wellContribs) const;
#endif

protected:
    // TODO: for now, not considering the polymer, solvent and so on to simplify the development process.

    // TODO: we need to have order for the primary variables and also the order for the well equations.
    // sometimes, they are similar, while sometimes, they can have very different forms.

    // Table showing the primary variable indices, depending on what phases are present:
    //
    //         WOG     OG     WG     WO    W/O/G (single phase)
    // GTotal    0      0      0      0                       0
    // WFrac     1  -1000      1      1                   -1000
    // GFrac     2      1  -1000  -1000                   -1000
    // Spres     3      2      2      2                       1

    static constexpr bool has_water = (Indices::waterSaturationIdx >= 0);
    static constexpr bool has_gas = (Indices::compositionSwitchIdx >= 0);
    static constexpr bool has_oil = (Indices::numPhases - has_gas - has_water) > 0;

    // In the implementation, one should use has_wfrac_variable
    // rather than has_water to check if you should do something
    // with the variable at the WFrac location, similar for GFrac.
    static constexpr bool has_wfrac_variable = has_water && Indices::numPhases > 1;
    static constexpr bool has_gfrac_variable = has_gas && has_oil;

    static constexpr int GTotal = 0;
    static constexpr int WFrac = has_wfrac_variable ? 1 : -1000;
    static constexpr int GFrac = has_gfrac_variable ? has_wfrac_variable + 1 : -1000;
    static constexpr int SPres = has_wfrac_variable + has_gfrac_variable + 1;

    //  the number of well equations  TODO: it should have a more general strategy for it
    static constexpr int numWellEq = Indices::numPhases + 1;

    // sparsity pattern for the matrices
    // [A C^T    [x       =  [ res
    //  B  D ]   x_well]      res_well]

    // the vector type for the res_well and x_well
    using VectorBlockWellType = Dune::FieldVector<Scalar, numWellEq>;
    using BVectorWell = Dune::BlockVector<VectorBlockWellType>;

    using VectorBlockType = Dune::FieldVector<Scalar, Indices::numEq>;
    using BVector = Dune::BlockVector<VectorBlockType>;

    // the matrix type for the diagonal matrix D
    using DiagMatrixBlockWellType = Dune::FieldMatrix<Scalar, numWellEq, numWellEq>;
    using DiagMatWell = Dune::BCRSMatrix<DiagMatrixBlockWellType>;

    // the matrix type for the non-diagonal matrix B and C^T
    using OffDiagMatrixBlockWellType = Dune::FieldMatrix<Scalar, numWellEq, Indices::numEq>;
    using OffDiagMatWell = Dune::BCRSMatrix<OffDiagMatrixBlockWellType>;

    // TODO: for more efficient implementation, we should have EvalReservoir, EvalWell, and EvalRerservoirAndWell
    //                                                         EvalR (Eval), EvalW, EvalRW
    // TODO: for now, we only use one type to save some implementation efforts, while improve later.
    using EvalWell = DenseAd::Evaluation<double, /*size=*/Indices::numEq + numWellEq>;
    using Eval = DenseAd::Evaluation<Scalar, /*size=*/Indices::numEq>;

    MultisegmentWellEval(WellInterfaceIndices<FluidSystem,Indices,Scalar>& baseif);

    void initMatrixAndVectors(const int num_cells) const;
    void initPrimaryVariablesEvaluation() const;

    void assembleControlEq(const WellState& well_state,
                           const GroupState& group_state,
                           const Schedule& schedule,
                           const SummaryState& summaryState,
                           const Well::InjectionControls& inj_controls,
                           const Well::ProductionControls& prod_controls,
                           const double rho,
                           DeferredLogger& deferred_logger);

    void assembleDefaultPressureEq(const int seg,
                                   WellState& well_state) const;


    // assemble pressure equation for ICD segments
    void assembleICDPressureEq(const int seg,
                               const UnitSystem& unit_system,
                               WellState& well_state,
                               DeferredLogger& deferred_logger) const;


    void assemblePressureEq(const int seg,
                            const UnitSystem& unit_system,
                            WellState& well_state,
                            DeferredLogger& deferred_logger) const;

    void checkConvergenceControlEq(const WellState& well_state,
                                   ConvergenceReport& report,
                                   const double tolerance_pressure_ms_wells,
                                   const double tolerance_wells,
                                   const double max_residual_allowed,
                                   DeferredLogger& deferred_logger) const;

    /// check whether the well equations get converged for this well
    ConvergenceReport getWellConvergence(const WellState& well_state,
                                         const std::vector<double>& B_avg,
                                         DeferredLogger& deferred_logger,
                                         const double max_residual_allowed,
                                         const double tolerance_wells,
                                         const double relaxed_inner_tolerance_flow_ms_well,
                                         const double tolerance_pressure_ms_wells,
                                         const double relaxed_inner_tolerance_pressure_ms_well,
                                         const bool relax_tolerance) const;

    // handling the overshooting and undershooting of the fractions
    void processFractions(const int seg) const;

    // xw = inv(D)*(rw - C*x)
    void recoverSolutionWell(const BVector& x,
                             BVectorWell& xw) const;

    void updatePrimaryVariables(const WellState& well_state) const;

    void updateUpwindingSegments();

    // updating the well_state based on well solution dwells
    void updateWellState(const BVectorWell& dwells,
                         const double relaxation_factor,
                         const double DFLimit,
                         const double max_pressure_change) const;

    void computeSegmentFluidProperties(const EvalWell& temperature,
                                       const EvalWell& saltConcentration,
                                       int pvt_region_index);

    EvalWell getBhp() const;
    EvalWell getFrictionPressureLoss(const int seg) const;
    EvalWell getHydroPressureLoss(const int seg) const;
    EvalWell getQs(const int comp_idx) const;
    EvalWell getSegmentGTotal(const int seg) const;
    EvalWell getSegmentPressure(const int seg) const;
    EvalWell getSegmentRate(const int seg, const int comp_idx) const;
    EvalWell getSegmentRateUpwinding(const int seg,
                                     const size_t comp_idx) const;
    EvalWell getSegmentSurfaceVolume(const EvalWell& temperature,
                                     const EvalWell& saltConcentration,
                                     const int pvt_region_index,
                                     const int seg_idx) const;
    EvalWell getWQTotal() const;


    std::vector<Scalar> getWellResiduals(const std::vector<Scalar>& B_avg,
                                         DeferredLogger& deferred_logger) const;

    double getControlTolerance(const WellState& well_state,
                               const double tolerance_wells,
                               const double tolerance_pressure_ms_wells,
                               DeferredLogger& deferred_logger) const;

    double getResidualMeasureValue(const WellState& well_state,
                                   const std::vector<double>& residuals,
                                   const double tolerance_wells,
                                   const double tolerance_pressure_ms_wells,
                                   DeferredLogger& deferred_logger) const;

    void handleAccelerationPressureLoss(const int seg,
                                        WellState& well_state) const;

    // pressure drop for Autonomous ICD segment (WSEGAICD)
    EvalWell pressureDropAutoICD(const int seg,
                                 const UnitSystem& unit_system) const;

    // pressure drop for Spiral ICD segment (WSEGSICD)
    EvalWell pressureDropSpiralICD(const int seg) const;

    // pressure drop for sub-critical valve (WSEGVALV)
    EvalWell pressureDropValve(const int seg) const;

    void updateThp(WellState& well_state,
                   const double rho,
                   DeferredLogger& deferred_logger) const;

    void updateWellStateFromPrimaryVariables(WellState& well_state,
                                             const double rho,
                                             DeferredLogger& deferred_logger) const;

    // fraction value of the primary variables
    // should we just use member variables to store them instead of calculating them again and again
    EvalWell volumeFraction(const int seg,
                            const unsigned compIdx) const;

    // F_p / g_p, the basic usage of this value is because Q_p = G_t * F_p / G_p
    EvalWell volumeFractionScaled(const int seg,
                                  const int comp_idx) const;

    // basically Q_p / \sigma_p Q_p
    EvalWell surfaceVolumeFraction(const int seg,
                                   const int comp_idx) const;

    // convert a Eval from reservoir to contain the derivative related to wells
    EvalWell extendEval(const Eval& in) const;

    const WellInterfaceIndices<FluidSystem,Indices,Scalar>& baseif_;

    // TODO, the following should go to a class for computing purpose
    // two off-diagonal matrices
    mutable OffDiagMatWell duneB_;
    mutable OffDiagMatWell duneC_;
    // "diagonal" matrix for the well. It has offdiagonal entries for inlets and outlets.
    mutable DiagMatWell duneD_;

    /// \brief solver for diagonal matrix
    ///
    /// This is a shared_ptr as MultisegmentWell is copied in computeWellPotentials...
    mutable std::shared_ptr<Dune::UMFPack<DiagMatWell> > duneDSolver_;

    // residuals of the well equations
    mutable BVectorWell resWell_;

    // the values for the primary varibles
    // based on different solutioin strategies, the wells can have different primary variables
    mutable std::vector<std::array<double, numWellEq> > primary_variables_;

    // the Evaluation for the well primary variables, which contain derivativles and are used in AD calculation
    mutable std::vector<std::array<EvalWell, numWellEq> > primary_variables_evaluation_;

    // the upwinding segment for each segment based on the flow direction
    std::vector<int> upwinding_segments_;

    // the densities of segment fluids
    // we should not have this member variable
    std::vector<EvalWell> segment_densities_;

    // the mass rate of the segments
    std::vector<EvalWell> segment_mass_rates_;

    // the viscosity of the segments
    std::vector<EvalWell> segment_viscosities_;

    std::vector<std::vector<EvalWell>> segment_phase_densities_;
    std::vector<std::vector<EvalWell>> segment_phase_fractions_;
    std::vector<std::vector<EvalWell>> segment_phase_viscosities_;

    // depth difference between perforations and the perforated grid cells
    std::vector<double> cell_perforation_depth_diffs_;
    // pressure correction due to the different depth of the perforation and
    // center depth of the grid block
    std::vector<double> cell_perforation_pressure_diffs_;
};

}

#endif // OPM_MULTISEGMENTWELL_GENERIC_HEADER_INCLUDED