/*
  Copyright 2014 SINTEF ICT, Applied Mathematics.
  Copyright 2015 Dr. Blatt - HPC-Simulation-Software & Services
  Copyright 2015 NTNU
  Copyright 2017 IRIS

  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_INITSTATEEQUIL_HEADER_INCLUDED
#define OPM_INITSTATEEQUIL_HEADER_INCLUDED

#include <opm/core/grid/GridHelpers.hpp>
#include <opm/core/simulator/EquilibrationHelpers.hpp>
#include <opm/core/utility/RegionMapping.hpp>
#include <opm/core/utility/extractPvtTableIndex.hpp>

#include <opm/parser/eclipse/Units/Units.hpp>
#include <opm/parser/eclipse/EclipseState/EclipseState.hpp>
#include <opm/parser/eclipse/EclipseState/Grid/GridProperty.hpp>
#include <opm/parser/eclipse/EclipseState/InitConfig/Equil.hpp>
#include <opm/parser/eclipse/EclipseState/InitConfig/InitConfig.hpp>
#include <opm/parser/eclipse/EclipseState/Tables/TableContainer.hpp>
#include <opm/parser/eclipse/EclipseState/Tables/TableManager.hpp>
#include <opm/parser/eclipse/EclipseState/Tables/RsvdTable.hpp>
#include <opm/parser/eclipse/EclipseState/Tables/RvvdTable.hpp>
#include <opm/common/OpmLog/OpmLog.hpp>
#include <opm/common/data/SimulationDataContainer.hpp>

#include <opm/material/fluidsystems/BlackOilFluidSystem.hpp>
#include <opm/material/fluidstates/SimpleModularFluidState.hpp>
#include <opm/material/fluidmatrixinteractions/EclMaterialLawManager.hpp>

#include <array>
#include <cassert>
#include <utility>
#include <vector>

/**
 * \file
 * Facilities for an ECLIPSE-style equilibration-based
 * initialisation scheme (keyword 'EQUIL').
 */
struct UnstructuredGrid;

namespace Opm
{


    /**
     * Types and routines that collectively implement a basic
     * ECLIPSE-style equilibration-based initialisation scheme.
     *
     * This namespace is intentionally nested to avoid name clashes
     * with other parts of OPM.
     */
    namespace EQUIL {

        /**
         * Compute initial phase pressures by means of equilibration.
         *
         * This function uses the information contained in an
         * equilibration record (i.e., depths and pressurs) as well as
         * a density calculator and related data to vertically
         * integrate the phase pressure ODE
         * \f[
         * \frac{\mathrm{d}p_{\alpha}}{\mathrm{d}z} =
         * \rho_{\alpha}(z,p_{\alpha})\cdot g
         * \f]
         * in which \f$\rho_{\alpha}$ denotes the fluid density of
         * fluid phase \f$\alpha\f$, \f$p_{\alpha}\f$ is the
         * corresponding phase pressure, \f$z\f$ is the depth and
         * \f$g\f$ is the acceleration due to gravity (assumed
         * directed downwords, in the positive \f$z\f$ direction).
         *
         * \tparam Region Type of an equilibration region information
         *                base.  Typically an instance of the EquilReg
         *                class template.
         *
         * \tparam CellRange Type of cell range that demarcates the
         *                cells pertaining to the current
         *                equilibration region.  Must implement
         *                methods begin() and end() to bound the range
         *                as well as provide an inner type,
         *                const_iterator, to traverse the range.
         *
         * \param[in] G     Grid.
         * \param[in] reg   Current equilibration region.
         * \param[in] cells Range that spans the cells of the current
         *                  equilibration region.
         * \param[in] grav  Acceleration of gravity.
         *
         * \return Phase pressures, one vector for each active phase,
         * of pressure values in each cell in the current
         * equilibration region.
         */
        template <class Grid, class Region, class CellRange, class FluidSystem>
        std::vector< std::vector<double> >
        phasePressures(const Grid&             G,
                       const Region&           reg,
                       const CellRange&        cells,
                       const double            grav = unit::gravity);



        /**
         * Compute initial phase saturations by means of equilibration.
         *
         * \tparam FluidSystem  The FluidSystem from opm-material
         *                      Must be initialized before used.
         *
         * \tparam Grid   Type of the grid
         *
         * \tparam Region Type of an equilibration region information
         *                base.  Typically an instance of the EquilReg
         *                class template.
         *
         * \tparam CellRange Type of cell range that demarcates the
         *                cells pertaining to the current
         *                equilibration region.  Must implement
         *                methods begin() and end() to bound the range
         *                as well as provide an inner type,
         *                const_iterator, to traverse the range.
         *
         * \tparam MaterialLawManager The MaterialLawManager from opm-material
         *
         * \param[in] G               Grid.
         * \param[in] reg             Current equilibration region.
         * \param[in] cells           Range that spans the cells of the current
         *                            equilibration region.
         * \param[in] materialLawManager   The MaterialLawManager from opm-material
         * \param[in] swat_init       A vector of initial water saturations.
         *                            The capillary pressure is scaled to fit these values
         * \param[in] phase_pressures Phase pressures, one vector for each active phase,
         *                            of pressure values in each cell in the current
         *                            equilibration region.
         * \return                    Phase saturations, one vector for each phase, each containing
         *                            one saturation value per cell in the region.
         */
        template <class FluidSystem, class Grid, class Region, class CellRange, class MaterialLawManager>
        std::vector< std::vector<double> >
        phaseSaturations(const Grid&             grid,
                         const Region&           reg,
                         const CellRange&        cells,
                         MaterialLawManager& materialLawManager,
                         const std::vector<double> swat_init,
                         std::vector< std::vector<double> >& phase_pressures);



        /**
         * Compute initial Rs values.
         *
         * \tparam CellRangeType Type of cell range that demarcates the
         *                cells pertaining to the current
         *                equilibration region.  Must implement
         *                methods begin() and end() to bound the range
         *                as well as provide an inner type,
         *                const_iterator, to traverse the range.
         *
         * \param[in] grid            Grid.
         * \param[in] cells           Range that spans the cells of the current
         *                            equilibration region.
         * \param[in] oil_pressure    Oil pressure for each cell in range.
         * \param[in] temperature     Temperature for each cell in range.
         * \param[in] rs_func         Rs as function of pressure and depth.
         * \return                    Rs values, one for each cell in the 'cells' range.
         */
        template <class Grid, class CellRangeType>
        std::vector<double> computeRs(const Grid& grid,
                                      const CellRangeType& cells,
                                      const std::vector<double> oil_pressure,
                                      const std::vector<double>& temperature,
                                      const Miscibility::RsFunction& rs_func,
                                      const std::vector<double> gas_saturation);

        namespace DeckDependent {
            inline
            std::vector<EquilRecord>
            getEquil(const Opm::EclipseState& state)
            {
                const auto& init = state.getInitConfig();

                if( !init.hasEquil() ) {
                    OPM_THROW(std::domain_error, "Deck does not provide equilibration data.");
                }

                const auto& equil = init.getEquil();
                return { equil.begin(), equil.end() };
            }

            template<class Grid>
            inline
            std::vector<int>
            equilnum(const Opm::EclipseState& eclipseState,
                     const Grid&  G   )
            {
                std::vector<int> eqlnum;
                if (eclipseState.get3DProperties().hasDeckIntGridProperty("EQLNUM")) {
                    const int nc = UgGridHelpers::numCells(G);
                    eqlnum.resize(nc);
                    const std::vector<int>& e = 
                        eclipseState.get3DProperties().getIntGridProperty("EQLNUM").getData();
                    const int* gc = UgGridHelpers::globalCell(G);
                    for (int cell = 0; cell < nc; ++cell) {
                        const int deck_pos = (gc == NULL) ? cell : gc[cell];
                        eqlnum[cell] = e[deck_pos] - 1;
                    }
                }
                else {
                    // No explicit equilibration region.
                    // All cells in region zero.
                    eqlnum.assign(UgGridHelpers::numCells(G), 0);
                }

                return eqlnum;
            }

            template<class FluidSystem>
            class InitialStateComputer {
            public:
                template<class MaterialLawManager, class Grid>
                InitialStateComputer(MaterialLawManager& materialLawManager,
                                     const Opm::EclipseState& eclipseState,
                                     const Grid&                        G    ,
                                     const double grav = unit::gravity,
                                     const bool applySwatInit = true
                                     )
                    : pp_(FluidSystem::numPhases,
                          std::vector<double>(UgGridHelpers::numCells(G))),
                      sat_(FluidSystem::numPhases,
                          std::vector<double>(UgGridHelpers::numCells(G))),
                      rs_(UgGridHelpers::numCells(G)),
                      rv_(UgGridHelpers::numCells(G))
                {
                    //Check for presence of kw SWATINIT
                    if (eclipseState.get3DProperties().hasDeckDoubleGridProperty("SWATINIT") && applySwatInit) {
                        const std::vector<double>& swat_init_ecl = eclipseState.
                                get3DProperties().getDoubleGridProperty("SWATINIT").getData();
                        const int nc = UgGridHelpers::numCells(G);
                        swat_init_.resize(nc);
                        const int* gc = UgGridHelpers::globalCell(G);
                        for (int c = 0; c < nc; ++c) {
                            const int deck_pos = (gc == NULL) ? c : gc[c];
                            swat_init_[c] = swat_init_ecl[deck_pos];
                        }
                    }
                    // Get the equilibration records.
                    const std::vector<EquilRecord> rec = getEquil(eclipseState);
                    const auto& tables = eclipseState.getTableManager();
                    // Create (inverse) region mapping.
                    const RegionMapping<> eqlmap(equilnum(eclipseState, G));
                    const int invalidRegion = -1;
                    regionPvtIdx_.resize(rec.size(), invalidRegion);
                    setRegionPvtIdx(G, eclipseState, eqlmap);

                    // Create Rs functions.
                    rs_func_.reserve(rec.size());
                    if (FluidSystem::enableDissolvedGas()) {
                        const TableContainer& rsvdTables = tables.getRsvdTables();
                        for (size_t i = 0; i < rec.size(); ++i) {
                            if (eqlmap.cells(i).empty())
                            {
                                rs_func_.push_back(std::shared_ptr<Miscibility::RsVD<FluidSystem>>());
                                continue;
                            }
                            const int pvtIdx = regionPvtIdx_[i];
                            if (!rec[i].liveOilInitConstantRs()) {
                                if (rsvdTables.size() <= 0 ) {
                                    OPM_THROW(std::runtime_error, "Cannot initialise: RSVD table not available.");
                                }
                                const RsvdTable& rsvdTable = rsvdTables.getTable<RsvdTable>(i);
                                std::vector<double> depthColumn = rsvdTable.getColumn("DEPTH").vectorCopy();
                                std::vector<double> rsColumn = rsvdTable.getColumn("RS").vectorCopy();
                                rs_func_.push_back(std::make_shared<Miscibility::RsVD<FluidSystem>>(pvtIdx,
                                                                                        depthColumn , rsColumn));
                            } else {
                                if (rec[i].gasOilContactDepth() != rec[i].datumDepth()) {
                                    OPM_THROW(std::runtime_error,
                                              "Cannot initialise: when no explicit RSVD table is given, \n"
                                              "datum depth must be at the gas-oil-contact. "
                                              "In EQUIL region " << (i + 1) << "  (counting from 1), this does not hold.");
                                }
                                const double p_contact = rec[i].datumDepthPressure();
                                const double T_contact = 273.15 + 20; // standard temperature for now
                                rs_func_.push_back(std::make_shared<Miscibility::RsSatAtContact<FluidSystem>>(pvtIdx, p_contact, T_contact));
                            }
                        }
                    } else {
                        for (size_t i = 0; i < rec.size(); ++i) {
                            rs_func_.push_back(std::make_shared<Miscibility::NoMixing>());
                        }
                    }                    

                    rv_func_.reserve(rec.size());
                    if (FluidSystem::enableVaporizedOil()) {
                        const TableContainer& rvvdTables = tables.getRvvdTables();
                        for (size_t i = 0; i < rec.size(); ++i) {
                            if (eqlmap.cells(i).empty())
                            {
                                rv_func_.push_back(std::shared_ptr<Miscibility::RvVD<FluidSystem>>());
                                continue;
                            }
                            const int pvtIdx = regionPvtIdx_[i];
                            if (!rec[i].wetGasInitConstantRv()) {
                                if (rvvdTables.size() <= 0) { 
                                    OPM_THROW(std::runtime_error, "Cannot initialise: RVVD table not available.");
                                }

                                const RvvdTable& rvvdTable = rvvdTables.getTable<RvvdTable>(i);
                                std::vector<double> depthColumn = rvvdTable.getColumn("DEPTH").vectorCopy();
                                std::vector<double> rvColumn = rvvdTable.getColumn("RV").vectorCopy();
                                rv_func_.push_back(std::make_shared<Miscibility::RvVD<FluidSystem>>(pvtIdx,
                                                                                        depthColumn , rvColumn));

                            } else {
                                if (rec[i].gasOilContactDepth() != rec[i].datumDepth()) {
                                    OPM_THROW(std::runtime_error,
                                              "Cannot initialise: when no explicit RVVD table is given, \n"
                                              "datum depth must be at the gas-oil-contact. "
                                              "In EQUIL region " << (i + 1) << "  (counting from 1), this does not hold.");
                                }
                                const double p_contact = rec[i].datumDepthPressure() + rec[i].gasOilContactCapillaryPressure();
                                const double T_contact = 273.15 + 20; // standard temperature for now
                                rv_func_.push_back(std::make_shared<Miscibility::RvSatAtContact<FluidSystem>>(pvtIdx ,p_contact, T_contact));
                            }
                        }
                    } else {
                        for (size_t i = 0; i < rec.size(); ++i) {
                            rv_func_.push_back(std::make_shared<Miscibility::NoMixing>());
                        }
                    }
                    
                    // Compute pressures, saturations, rs and rv factors.
                    calcPressSatRsRv(eqlmap, rec, materialLawManager, G, grav);

                    // Modify oil pressure in no-oil regions so that the pressures of present phases can
                    // be recovered from the oil pressure and capillary relations.
                }

                typedef std::vector<double> Vec;
                typedef std::vector<Vec>    PVec; // One per phase.

                const PVec& press() const { return pp_; }
                const PVec& saturation() const { return sat_; }
                const Vec& rs() const { return rs_; }
                const Vec& rv() const { return rv_; }

            private:
                typedef EquilReg EqReg;
                std::vector< std::shared_ptr<Miscibility::RsFunction> > rs_func_;
                std::vector< std::shared_ptr<Miscibility::RsFunction> > rv_func_;
                std::vector<int> regionPvtIdx_;
                PVec pp_;
                PVec sat_;
                Vec rs_;
                Vec rv_;
                Vec swat_init_;

                template<class Grid, class RMap>
                void setRegionPvtIdx(const Grid& G, const Opm::EclipseState& eclipseState, const RMap& reg) {

                    std::vector<int> cellPvtRegionIdx;
                    extractPvtTableIndex(cellPvtRegionIdx, eclipseState, UgGridHelpers::numCells(G), UgGridHelpers::globalCell(G));
                    for (const auto& r : reg.activeRegions()) {
                        const auto& cells = reg.cells(r);
                        const int cell = *(cells.begin());
                        regionPvtIdx_[r] = cellPvtRegionIdx[cell];
                    }
                }

                template <class RMap, class MaterialLawManager, class Grid>
                void
                calcPressSatRsRv(const RMap&                       reg  ,
                                 const std::vector< EquilRecord >& rec  ,
                                 MaterialLawManager& materialLawManager,
                                 const Grid&                       G    ,
                                 const double grav)
                {
                    for (const auto& r : reg.activeRegions()) {
                        const auto& cells = reg.cells(r);
                        if (cells.empty())
                        {
                            OpmLog::warning("Equilibration region " + std::to_string(r + 1) 
                                            + " has no active cells");
                            continue;
                        }

                        const EqReg eqreg(rec[r], rs_func_[r], rv_func_[r], regionPvtIdx_[r]);
                   
                        PVec pressures = phasePressures<FluidSystem>(G, eqreg, cells, grav);
                        const std::vector<double>& temp = temperature(G, eqreg, cells);
                        const PVec sat = phaseSaturations<FluidSystem>(G, eqreg, cells, materialLawManager, swat_init_, pressures);

                        const int np = FluidSystem::numPhases;
                        for (int p = 0; p < np; ++p) {
                            copyFromRegion(pressures[p], cells, pp_[p]);
                            copyFromRegion(sat[p], cells, sat_[p]);
                        }
                        const bool oil = FluidSystem::phaseIsActive(FluidSystem::oilPhaseIdx);
                        const bool gas = FluidSystem::phaseIsActive(FluidSystem::gasPhaseIdx);
                        if (oil && gas) {
                            const int oilpos = FluidSystem::oilPhaseIdx;
                            const int gaspos = FluidSystem::gasPhaseIdx;
                            const Vec rs_vals = computeRs(G, cells, pressures[oilpos], temp, *(rs_func_[r]), sat[gaspos]);
                            const Vec rv_vals = computeRs(G, cells, pressures[gaspos], temp, *(rv_func_[r]), sat[oilpos]);
                            copyFromRegion(rs_vals, cells, rs_);
                            copyFromRegion(rv_vals, cells, rv_);
                        }
                    }
                }

                template <class CellRangeType>
                void copyFromRegion(const Vec& source,
                                    const CellRangeType& cells,
                                    Vec& destination)
                {
                    auto s = source.begin();
                    auto c = cells.begin();
                    const auto e = cells.end();
                    for (; c != e; ++c, ++s) {
                        destination[*c] = *s;
                    }
                }

            };
        } // namespace DeckDependent
    } // namespace EQUIL
} // namespace Opm

#include <opm/core/simulator/initStateEquil_impl.hpp>

#endif // OPM_INITSTATEEQUIL_HEADER_INCLUDED