RegionPhasePVAverage.hpp

// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
/*
  Copyright 2024 Equinor AS

  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_REGION_PHASE_POREVOL_AVERAGE_MODULE_HPP
#define OPM_REGION_PHASE_POREVOL_AVERAGE_MODULE_HPP

#include <opm/simulators/utils/ParallelCommunication.hpp>

#include <cstddef>
#include <functional>
#include <string>
#include <string_view>
#include <vector>

namespace Opm {

    class RegionPhasePoreVolAverage
    {
    public:
        struct CellValue
        {
            double value { 0.0 };

            double sat { 0.0 };

            double porv { 0.0 };
        };

        struct Phase
        {
            unsigned int ix;
        };

        struct Region
        {
            unsigned int ix;
        };

        using RegionArrayAccessor = std::function<const std::vector<int>&(const std::string&)>;

        explicit RegionPhasePoreVolAverage(const Parallel::Communication&  comm,
                                           std::size_t                     numPhases,
                                           const std::vector<std::string>& regionNames,
                                           RegionArrayAccessor             getRegionArray);

        double fieldValue(const Phase& p) const;

        double value(std::string_view rset, const Phase& p, const Region& r) const;

        void prepareAccumulation();

        void addCell(std::size_t activeCell, const Phase& p, const CellValue& cv);

        void accumulateParallel();

    private:
        using Ix = std::vector<double>::size_type;

        enum AvgType {
            SatPV,              //< Weighted by phase-filled pore-volume.
            PV,                 //< Weighted by total pore-volume (s=1).

            // ---- Must be last enumerator ----
            NumTypes,           //< Number of averge types.
        };

        enum Element {
            Value,              //< Running sum of weighted function values.
            Weight,             //< Running sum of weights.

            // ---- Must be last enumerator ----
            NumElem,            //< Number of items/elements per average type.
        };

        std::reference_wrapper<const Parallel::Communication> comm_;

        std::size_t np_{};

        std::vector<std::string> rsetNames_{};

        RegionArrayAccessor getRegionArray_;

        std::vector<Ix> rsStart_{};

        std::vector<double> x_{};

        double averageValueWithFallback(Ix start) const;

        double averageValue(Ix start, AvgType type) const;

        Ix fieldStartIx(unsigned int phase) const;

        Ix rsetStartIx(std::size_t rset, int region, unsigned int phase) const;

        Ix startIx(std::size_t offset, unsigned int phase) const;

        int regionIndex(std::size_t rset, std::size_t activeCell) const;

        void add(Ix start, const CellValue& cv);

        void add(Ix start, AvgType type, double x, double w);

        double& value(Ix start, AvgType type);

        double& weight(Ix start, AvgType type);

        double value(Ix start, AvgType type) const;

        double weight(Ix start, AvgType type) const;

        Ix valueArrayIndex(Ix start, AvgType type, Element element) const;
    };
} // namespace Opm

#endif // OPM_REGION_PHASE_POREVOL_AVERAGE_MODULE_HPP