/*---------------------------------------------------------------------------*\
  ==  == ====== ====   ====    |
                    \\     ||  | Multiphase Code Repository by HZDR
  ======   //   ||  || ===//   | Website: https://doi.org/10.14278/rodare.767
  ||  ||  //    ||  // || \\   | License: GPL-3.0-or-later
  ==  == ====== ====   ==  ==  |
-------------------------------------------------------------------------------
License
    This file is part of the Multiphase Code Repository by HZDR.

    Copyright (C) 2025 by Helmholtz-Zentrum Dresden-Rossendorf e.V. (HZDR),
    Website: https://hzdr.de

    Multiphase Code Repository by HZDR is based on the free software for
    computational fluid dynamics (CFD) from the OpenFOAM Foundation.
    Copyright (C) 2025 by OpenFOAM Foundation, Website: https://openfoam.org

    If you are interested in which files are original OpenFOAM Foundation
    files, which OpenFOAM Foundation files were modified, and which files were
    newly created, see FILES.md.

    Multiphase Code Repository by HZDR 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.

    Multiphase Code Repository by HZDR 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
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\*---------------------------------------------------------------------------*/

#include "populationBalanceMoments.H"
#include "addToRunTimeSelectionTable.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
namespace functionObjects
{
    defineTypeNameAndDebug(populationBalanceMoments, 0);
    addToRunTimeSelectionTable
    (
        functionObject,
        populationBalanceMoments,
        dictionary
    );
}
}

const Foam::NamedEnum
<
    Foam::functionObjects::populationBalanceMoments::momentType,
    4
>
Foam::functionObjects::populationBalanceMoments::momentTypeNames_
{"integerMoment", "mean", "variance", "stdDev"};

const Foam::NamedEnum
<
    Foam::functionObjects::populationBalanceMoments::coordinateType,
    3
>
Foam::functionObjects::populationBalanceMoments::coordinateTypeNames_
{"volume", "area", "diameter"};

const Foam::NamedEnum
<
    Foam::functionObjects::populationBalanceMoments::weightType,
    3
>
Foam::functionObjects::populationBalanceMoments::weightTypeNames_
{
    "numberConcentration",
    "volumeConcentration",
    "areaConcentration"
};

const Foam::NamedEnum
<
    Foam::functionObjects::populationBalanceMoments::meanType,
    3
>
Foam::functionObjects::populationBalanceMoments::meanTypeNames_
{"arithmetic", "geometric", "notApplicable"};


// * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * * //

Foam::word
Foam::functionObjects::populationBalanceMoments::coordinateTypeSymbolicName()
{
    word coordinateTypeSymbolicName(word::null);

    switch (coordinateType_)
    {
        case coordinateType::volume:
        {
            coordinateTypeSymbolicName = "v";

            break;
        }
        case coordinateType::area:
        {
            coordinateTypeSymbolicName = "a";

            break;
        }
        case coordinateType::diameter:
        {
            coordinateTypeSymbolicName = "d";

            break;
        }
    }

    return coordinateTypeSymbolicName;
}


Foam::word
Foam::functionObjects::populationBalanceMoments::weightTypeSymbolicName()
{
    word weightTypeSymbolicName(word::null);

    switch (weightType_)
    {
        case weightType::numberConcentration:
        {
            weightTypeSymbolicName = "N";

            break;
        }
        case weightType::volumeConcentration:
        {
            weightTypeSymbolicName = "V";

            break;
        }
        case weightType::areaConcentration:
        {
            weightTypeSymbolicName = "A";

            break;
        }
    }

    return weightTypeSymbolicName;
}


Foam::word Foam::functionObjects::populationBalanceMoments::defaultFldName()
{
    word meanName
    (
        meanType_ == meanType::geometric
      ? word(meanTypeNames_[meanType_]).capitalise()
      : word("")
    );

    return
        word
        (
            IOobject::groupName
            (
                "weighted"
              + meanName
              + word(momentTypeNames_[momentType_]).capitalise()
              + "("
              + weightTypeSymbolicName()
              + ","
              + coordinateTypeSymbolicName()
              + ")",
                popBalName_
            )
        );
}


Foam::word
Foam::functionObjects::populationBalanceMoments::integerMomentFldName()
{
    return
        word
        (
            IOobject::groupName
            (
                word(momentTypeNames_[momentType_])
              + Foam::name(order_)
              + "("
              + weightTypeSymbolicName()
              + ","
              + coordinateTypeSymbolicName()
              + ")",
                popBalName_
            )
        );
}


void Foam::functionObjects::populationBalanceMoments::setDimensions
(
    volScalarField& fld,
    momentType momType
)
{
    switch (momType)
    {
        case momentType::integerMoment:
        {
            switch (coordinateType_)
            {
                case coordinateType::volume:
                {
                    fld.dimensions().reset
                    (
                        pow(dimVolume, order_)/dimVolume
                    );

                    break;
                }
                case coordinateType::area:
                {
                    fld.dimensions().reset
                    (
                        pow(dimArea, order_)/dimVolume
                    );

                    break;
                }
                case coordinateType::diameter:
                {
                    fld.dimensions().reset
                    (
                        pow(dimLength, order_)/dimVolume
                    );

                    break;
                }
            }

            switch (weightType_)
            {
                case weightType::volumeConcentration:
                {
                    fld.dimensions().reset(fld.dimensions()*dimVolume);

                    break;
                }
                case weightType::areaConcentration:
                {
                    fld.dimensions().reset(fld.dimensions()*dimArea);

                    break;
                }
                default:
                {
                    break;
                }
            }

            break;
        }
        case momentType::mean:
        {
            switch (coordinateType_)
            {
                case coordinateType::volume:
                {
                    fld.dimensions().reset(dimVolume);

                    break;
                }
                case coordinateType::area:
                {
                    fld.dimensions().reset(dimArea);

                    break;
                }
                case coordinateType::diameter:
                {
                    fld.dimensions().reset(dimLength);

                    break;
                }
            }

            break;
        }
        case momentType::variance:
        {
            switch (coordinateType_)
            {
                case coordinateType::volume:
                {
                    fld.dimensions().reset(sqr(dimVolume));

                    break;
                }
                case coordinateType::area:
                {
                    fld.dimensions().reset(sqr(dimArea));

                    break;
                }
                case coordinateType::diameter:
                {
                    fld.dimensions().reset(sqr(dimLength));

                    break;
                }
            }

            if (meanType_ == meanType::geometric)
            {
                fld.dimensions().reset(dimless);
            }

            break;
        }
        case momentType::stdDev:
        {
            switch (coordinateType_)
            {
                case coordinateType::volume:
                {
                    fld.dimensions().reset(dimVolume);

                    break;
                }
                case coordinateType::area:
                {
                    fld.dimensions().reset(dimArea);

                    break;
                }
                case coordinateType::diameter:
                {
                    fld.dimensions().reset(dimLength);

                    break;
                }
            }

            if (meanType_ == meanType::geometric)
            {
                fld.dimensions().reset(dimless);
            }

            break;
        }
    }
}


Foam::tmp<Foam::volScalarField>
Foam::functionObjects::populationBalanceMoments::totalConcentration
(
    const populationBalanceModel& popBal
)
{
    tmp<volScalarField> tTotalConcentration
    (
        volScalarField::New
        (
            "totalConcentration",
            mesh_,
            dimensionedScalar(inv(dimVolume), Zero)
        )
    );

    volScalarField& totalConcentration = tTotalConcentration.ref();

    switch (weightType_)
    {
        case weightType::volumeConcentration:
        {
            totalConcentration.dimensions().reset
            (
                totalConcentration.dimensions()*dimVolume
            );

            break;
        }
        case weightType::areaConcentration:
        {
            totalConcentration.dimensions().reset
            (
                totalConcentration.dimensions()*dimArea
            );

            break;
        }
        default:
        {
            break;
        }
    }

    forAll(popBal.fs(), i)
    {
        const volScalarField& alpha = popBal.phases()[i];
        const volScalarField& fi = popBal.f(i);
        const dimensionedScalar& vi = popBal.v(i);

        switch (weightType_)
        {
            case weightType::numberConcentration:
            {
                totalConcentration += fi*alpha/vi;

                break;
            }
            case weightType::volumeConcentration:
            {
                totalConcentration += fi*alpha;

                break;
            }
            case weightType::areaConcentration:
            {
                totalConcentration += popBal.a(i)*fi*alpha/vi;

                break;
            }
        }
    }

    return tTotalConcentration;
}


Foam::tmp<Foam::volScalarField>
Foam::functionObjects::populationBalanceMoments::mean
(
    const populationBalanceModel& popBal
)
{
    tmp<volScalarField> tMean
    (
        volScalarField::New
        (
            "mean",
            mesh_,
            dimensionedScalar(dimless, Zero)
        )
    );

    volScalarField& mean = tMean.ref();

    setDimensions(mean, momentType::mean);

    volScalarField totalConcentration(this->totalConcentration(popBal));

    forAll(popBal.fs(), i)
    {
        const volScalarField& alpha = popBal.phases()[i];
        const volScalarField& fi = popBal.f(i);
        const dimensionedScalar& vi = popBal.v(i);

        volScalarField concentration(fi*alpha/vi);

        switch (weightType_)
        {
            case weightType::volumeConcentration:
            {
                concentration *= vi;

                break;
            }
            case weightType::areaConcentration:
            {
                concentration *= popBal.a(i);

                break;
            }
            default:
            {
                break;
            }
        }

        switch (meanType_)
        {
            case meanType::geometric:
            {
                mean.dimensions().reset(dimless);

                switch (coordinateType_)
                {
                    case coordinateType::volume:
                    {
                        dimensionedScalar unitVolume(dimVolume, 1);

                        mean +=
                            Foam::log(vi/unitVolume)
                           *concentration/totalConcentration;

                        break;
                    }
                    case coordinateType::area:
                    {
                        dimensionedScalar unitArea(dimArea, 1);

                        mean +=
                            Foam::log(popBal.a(i)/unitArea)
                           *concentration/totalConcentration;

                        break;
                    }
                    case coordinateType::diameter:
                    {
                        dimensionedScalar unitLength(dimLength, 1);

                        mean +=
                            Foam::log(popBal.d(i)/unitLength)
                           *concentration/totalConcentration;

                        break;
                    }
                }

                break;
            }
            default:
            {
                switch (coordinateType_)
                {
                    case coordinateType::volume:
                    {
                        mean += vi*concentration/totalConcentration;

                        break;
                    }
                    case coordinateType::area:
                    {
                        mean += popBal.a(i)*concentration/totalConcentration;

                        break;
                    }
                    case coordinateType::diameter:
                    {
                        mean += popBal.d(i)*concentration/totalConcentration;

                        break;
                    }
                }

                break;
            }
        }
    }

    if (meanType_ == meanType::geometric)
    {
        mean = exp(mean);

        setDimensions(mean, momentType::mean);
    }

    return tMean;
}


Foam::tmp<Foam::volScalarField>
Foam::functionObjects::populationBalanceMoments::variance
(
    const populationBalanceModel& popBal
)
{
    tmp<volScalarField> tVariance
    (
        volScalarField::New
        (
            "variance",
            mesh_,
            dimensionedScalar(dimless, Zero)
        )
    );

    volScalarField& variance = tVariance.ref();

    setDimensions(variance, momentType::variance);

    volScalarField totalConcentration(this->totalConcentration(popBal));
    volScalarField mean(this->mean(popBal));

    forAll(popBal.fs(), i)
    {
        const volScalarField& alpha = popBal.phases()[i];
        const volScalarField& fi = popBal.f(i);
        const dimensionedScalar& vi = popBal.v(i);

        volScalarField concentration(fi*alpha/vi);

        switch (weightType_)
        {
            case weightType::volumeConcentration:
            {
                concentration *= vi;

                break;
            }
            case weightType::areaConcentration:
            {
                concentration *= popBal.a(i);

                break;
            }
            default:
            {
                break;
            }
        }

        switch (meanType_)
        {
            case meanType::geometric:
            {
                switch (coordinateType_)
                {
                    case coordinateType::volume:
                    {
                        variance +=
                            sqr(Foam::log(vi/mean))
                           *concentration/totalConcentration;

                        break;
                    }
                    case coordinateType::area:
                    {
                        variance +=
                            sqr(Foam::log(popBal.a(i)/mean))
                           *concentration/totalConcentration;

                        break;
                    }
                    case coordinateType::diameter:
                    {
                        variance +=
                            sqr(Foam::log(popBal.d(i)/mean))
                           *concentration/totalConcentration;

                        break;
                    }
                }

                break;
            }
            default:
            {
                switch (coordinateType_)
                {
                    case coordinateType::volume:
                    {
                        variance +=
                            sqr(vi - mean)*concentration/totalConcentration;

                        break;
                    }
                    case coordinateType::area:
                    {
                        variance +=
                            sqr(popBal.a(i) - mean)
                           *concentration
                           /totalConcentration;

                        break;
                    }
                    case coordinateType::diameter:
                    {
                        variance +=
                            sqr(popBal.d(i) - mean)
                           *concentration
                           /totalConcentration;

                        break;
                    }
                }

                break;
            }
        }
    }

    return tVariance;
}


Foam::tmp<Foam::volScalarField>
Foam::functionObjects::populationBalanceMoments::stdDev
(
    const populationBalanceModel& popBal
)
{
    switch (meanType_)
    {
        case meanType::geometric:
        {
            return exp(sqrt(this->variance(popBal)));
        }
        default:
        {
            return sqrt(this->variance(popBal));
        }
    }
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::functionObjects::populationBalanceMoments::populationBalanceMoments
(
    const word& name,
    const Time& runTime,
    const dictionary& dict
)
:
    fvMeshFunctionObject(name, runTime, dict),
    popBalName_(dict.lookup("populationBalance")),
    momentType_(momentTypeNames_.read(dict.lookup("momentType"))),
    coordinateType_(coordinateTypeNames_.read(dict.lookup("coordinateType"))),
    weightType_
    (
        dict.found("weightType")
      ? weightTypeNames_.read(dict.lookup("weightType"))
      : weightType::numberConcentration
    ),
    meanType_(meanType::notApplicable),
    order_(-1),
    fldPtr_(nullptr)
{
    read(dict);
}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

Foam::functionObjects::populationBalanceMoments::~populationBalanceMoments()
{}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

bool
Foam::functionObjects::populationBalanceMoments::read(const dictionary& dict)
{
    fvMeshFunctionObject::read(dict);

    switch (momentType_)
    {
        case momentType::integerMoment:
        {
            order_ = dict.lookup<int>("order");

            break;
        }
        default:
        {
            meanType_ =
                dict.found("meanType")
              ? meanTypeNames_.read(dict.lookup("meanType"))
              : meanType::arithmetic;

            break;
        }
    }

    switch (momentType_)
    {
        case momentType::integerMoment:
        {
            fldPtr_.set
            (
                new volScalarField
                (
                    IOobject
                    (
                        this->integerMomentFldName(),
                        mesh_.time().name(),
                        mesh_,
                        IOobject::NO_READ,
                        IOobject::NO_WRITE
                    ),
                    mesh_,
                    dimensionedScalar(dimless, Zero)
                )
            );

            volScalarField& integerMoment = fldPtr_();

            setDimensions(integerMoment, momentType::integerMoment);

            break;
        }
        case momentType::mean:
        {
            fldPtr_.set
            (
                new volScalarField
                (
                    IOobject
                    (
                        this->defaultFldName(),
                        mesh_.time().name(),
                        mesh_,
                        IOobject::NO_READ,
                        IOobject::NO_WRITE
                    ),
                    mesh_,
                    dimensionedScalar(dimless, Zero)
                )
            );

            setDimensions(fldPtr_(), momentType::mean);

            break;
        }
        case momentType::variance:
        {
            fldPtr_.set
            (
                new volScalarField
                (
                    IOobject
                    (
                        this->defaultFldName(),
                        mesh_.time().name(),
                        mesh_,
                        IOobject::NO_READ,
                        IOobject::NO_WRITE
                    ),
                    mesh_,
                    dimensionedScalar(dimless, Zero)
                )
            );

            setDimensions(fldPtr_(), momentType::variance);

            break;
        }
        case momentType::stdDev:
        {
            fldPtr_.set
            (
                new volScalarField
                (
                    IOobject
                    (
                        this->defaultFldName(),
                        mesh_.time().name(),
                        mesh_,
                        IOobject::NO_READ,
                        IOobject::NO_WRITE
                    ),
                    mesh_,
                    dimensionedScalar(dimless, Zero)
                )
            );

            setDimensions(fldPtr_(), momentType::stdDev);

            break;
        }
    }

    return true;
}


bool Foam::functionObjects::populationBalanceMoments::execute()
{
    const populationBalanceModel& popBal =
        obr_.lookupObject<populationBalanceModel>(popBalName_);

    switch (momentType_)
    {
        case momentType::integerMoment:
        {
            volScalarField& integerMoment = fldPtr_();

            integerMoment = Zero;

            forAll(popBal.fs(), i)
            {
                const volScalarField& alpha = popBal.phases()[i];
                const volScalarField& fi = popBal.f(i);
                const dimensionedScalar& vi = popBal.v(i);

                volScalarField concentration(fi*alpha/vi);

                switch (weightType_)
                {
                    case weightType::volumeConcentration:
                    {
                        concentration *= vi;

                        break;
                    }
                    case weightType::areaConcentration:
                    {
                        concentration *= popBal.a(i);

                        break;
                    }
                    default:
                    {
                        break;
                    }
                }

                switch (coordinateType_)
                {
                    case coordinateType::volume:
                    {
                        integerMoment +=
                            pow(vi, order_)*concentration;

                        break;
                    }
                    case coordinateType::area:
                    {
                        integerMoment +=
                            pow(popBal.a(i), order_)*concentration;

                        break;
                    }
                    case coordinateType::diameter:
                    {
                        integerMoment +=
                            pow(popBal.d(i), order_)*concentration;

                        break;
                    }
                }
            }

            break;
        }
        case momentType::mean:
        {
            fldPtr_() = this->mean(popBal);

            break;
        }
        case momentType::variance:
        {
            fldPtr_() = this->variance(popBal);

            break;
        }
        case momentType::stdDev:
        {
            fldPtr_() = sqrt(this->variance(popBal));

            break;
        }
    }

    return true;
}


bool Foam::functionObjects::populationBalanceMoments::write()
{
    writeObject(fldPtr_->name());

    return true;
}


// ************************************************************************* //
