/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 1991-2010 OpenCFD Ltd.
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM 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.

    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
    
\*---------------------------------------------------------------------------*/

#include "boundedBackwardDdtScheme.H"
#include <finiteVolume/surfaceInterpolate.H>
#include <finiteVolume/fvcDiv.H>

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

namespace Foam
{

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

namespace fv
{

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

scalar boundedBackwardDdtScheme::deltaT_() const
{
    return mesh().time().deltaT().value();
}


scalar boundedBackwardDdtScheme::deltaT0_() const
{
    return mesh().time().deltaT0().value();
}


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

tmp<volScalarField>
boundedBackwardDdtScheme::fvcDdt
(
    const dimensionedScalar& dt
)
{
    // No change compared to backward

    dimensionedScalar rDeltaT = 1.0/mesh().time().deltaT();

    IOobject ddtIOobject
    (
        "ddt("+dt.name()+')',
        mesh().time().timeName(),
        mesh()
    );

    scalar deltaT = deltaT_();
    scalar deltaT0 = deltaT0_();

    scalar coefft   = 1 + deltaT/(deltaT + deltaT0);
    scalar coefft00 = deltaT*deltaT/(deltaT0*(deltaT + deltaT0));
    scalar coefft0  = coefft + coefft00;

    if (mesh().moving())
    {
        tmp<volScalarField> tdtdt
        (
            new volScalarField
            (
                ddtIOobject,
                mesh(),
                dimensionedScalar
                (
                    "0",
                    dt.dimensions()/dimTime,
                    0.0
                )
            )
        );

        tdtdt().internalField() = rDeltaT.value()*dt.value()*
        (
            coefft - (coefft0*mesh().V0() - coefft00*mesh().V00())/mesh().V()
        );

        return tdtdt;
    }
    else
    {
        return tmp<volScalarField>
        (
            new volScalarField
            (
                ddtIOobject,
                mesh(),
                dimensionedScalar
                (
                    "0",
                    dt.dimensions()/dimTime,
                    0.0
                ),
                calculatedFvPatchScalarField::typeName
            )
        );
    }
}


tmp<volScalarField>
boundedBackwardDdtScheme::fvcDdt
(
    const volScalarField& vf
)
{
    dimensionedScalar rDeltaT = 1.0/mesh().time().deltaT();

    IOobject ddtIOobject
    (
        "ddt("+vf.name()+')',
        mesh().time().timeName(),
        mesh()
    );

    scalar deltaT = deltaT_();
    scalar deltaT0 = deltaT0_(vf);

    // Calculate unboundedness indicator
    // Note: all times moved by one because access to internal field
    // copies current field into the old-time level.
    volScalarField phict =
        mag
        (
            vf.oldTime().oldTime()
          - vf.oldTime().oldTime().oldTime()
        )/
        (
            mag
            (
                vf.oldTime()
              - vf.oldTime().oldTime()
            )
          + dimensionedScalar("small", vf.dimensions(), VSMALL)
        );

    volScalarField limiter(pos(phict) - pos(phict - scalar(1)));

    volScalarField coefft   = scalar(1) + limiter*deltaT/(deltaT + deltaT0);
    volScalarField coefft00 = limiter*sqr(deltaT)/(deltaT0*(deltaT + deltaT0));
    volScalarField coefft0  = coefft + coefft00;

    if (mesh().moving())
    {
        return tmp<volScalarField>
        (
            new volScalarField
            (
                ddtIOobject,
                mesh(),
                rDeltaT.dimensions()*vf.dimensions(),
                rDeltaT.value()*
                (
                    coefft*vf.internalField() -
                    (
                        coefft0.internalField()
                        *vf.oldTime().internalField()*mesh().V0()
                      - coefft00.internalField()
                        *vf.oldTime().oldTime().internalField()
                       *mesh().V00()
                    )/mesh().V()
                ),
                rDeltaT.value()*
                (
                    coefft.boundaryField()*vf.boundaryField() -
                    (
                        coefft0.boundaryField()*
                        vf.oldTime().boundaryField()
                      - coefft00.boundaryField()*
                        vf.oldTime().oldTime().boundaryField()
                    )
                )
            )
        );
    }
    else
    {
        return tmp<volScalarField>
        (
            new volScalarField
            (
                ddtIOobject,
                rDeltaT*
                (
                    coefft*vf
                  - coefft0*vf.oldTime()
                  + coefft00*vf.oldTime().oldTime()
                )
            )
        );
    }
}


tmp<volScalarField>
boundedBackwardDdtScheme::fvcDdt
(
    const dimensionedScalar& rho,
    const volScalarField& vf
)
{
    dimensionedScalar rDeltaT = 1.0/mesh().time().deltaT();

    IOobject ddtIOobject
    (
        "ddt("+rho.name()+','+vf.name()+')',
        mesh().time().timeName(),
        mesh()
    );

    scalar deltaT = deltaT_();
    scalar deltaT0 = deltaT0_(vf);

    // Calculate unboundedness indicator
    // Note: all times moved by one because access to internal field
    // copies current field into the old-time level.
    volScalarField phict =
        mag
        (
            vf.oldTime().oldTime()
          - vf.oldTime().oldTime().oldTime()
        )/
        (
            mag
            (
                vf.oldTime()
              - vf.oldTime().oldTime()
            )
          + dimensionedScalar("small", vf.dimensions(), VSMALL)
        );

    volScalarField limiter(pos(phict) - pos(phict - scalar(1)));

    volScalarField coefft   = scalar(1) + limiter*deltaT/(deltaT + deltaT0);
    volScalarField coefft00 = limiter*sqr(deltaT)/(deltaT0*(deltaT + deltaT0));
    volScalarField coefft0  = coefft + coefft00;

    if (mesh().moving())
    {
        return tmp<volScalarField>
        (
            new volScalarField
            (
                ddtIOobject,
                mesh(),
                rDeltaT.dimensions()*rho.dimensions()*vf.dimensions(),
                rDeltaT.value()*rho.value()*
                (
                    coefft*vf.internalField() -
                    (
                        coefft0.internalField()*
                        vf.oldTime().internalField()*mesh().V0()
                      - coefft00.internalField()*
                        vf.oldTime().oldTime().internalField()
                       *mesh().V00()
                    )/mesh().V()
                ),
                rDeltaT.value()*rho.value()*
                (
                    coefft.boundaryField()*vf.boundaryField() -
                    (
                        coefft0.boundaryField()*
                        vf.oldTime().boundaryField()
                      - coefft00.boundaryField()*
                        vf.oldTime().oldTime().boundaryField()
                    )
                )
            )
        );
    }
    else
    {
        return tmp<volScalarField>
        (
            new volScalarField
            (
                ddtIOobject,
                rDeltaT*rho*
                (
                    coefft*vf
                  - coefft0*vf.oldTime()
                 + coefft00*vf.oldTime().oldTime()
                )
            )
        );
    }
}


tmp<volScalarField>
boundedBackwardDdtScheme::fvcDdt
(
    const volScalarField& rho,
    const volScalarField& vf
)
{
    dimensionedScalar rDeltaT = 1.0/mesh().time().deltaT();

    IOobject ddtIOobject
    (
        "ddt("+rho.name()+','+vf.name()+')',
        mesh().time().timeName(),
        mesh()
    );

    scalar deltaT = deltaT_();
    scalar deltaT0 = deltaT0_(vf);

    // Calculate unboundedness indicator
    // Note: all times moved by one because access to internal field
    // copies current field into the old-time level.
    volScalarField phict =
        mag
        (
            rho.oldTime().oldTime()*vf.oldTime().oldTime()
          - rho.oldTime().oldTime().oldTime()*vf.oldTime().oldTime().oldTime()
        )/
        (
            mag
            (
                rho.oldTime()*vf.oldTime()
              - rho.oldTime().oldTime()*vf.oldTime().oldTime()
            )
          + dimensionedScalar("small", rho.dimensions()*vf.dimensions(), VSMALL)
        );

    volScalarField limiter(pos(phict) - pos(phict - scalar(1)));

    volScalarField coefft   = scalar(1) + limiter*deltaT/(deltaT + deltaT0);
    volScalarField coefft00 = limiter*sqr(deltaT)/(deltaT0*(deltaT + deltaT0));
    volScalarField coefft0  = coefft + coefft00;

    if (mesh().moving())
    {
        return tmp<volScalarField>
        (
            new volScalarField
            (
                ddtIOobject,
                mesh(),
                rDeltaT.dimensions()*rho.dimensions()*vf.dimensions(),
                rDeltaT.value()*
                (
                    coefft*rho.internalField()*vf.internalField() -
                    (
                        coefft0.internalField()*
                        rho.oldTime().internalField()*
                        vf.oldTime().internalField()*mesh().V0()
                      - coefft00.internalField()*
                        rho.oldTime().oldTime().internalField()
                       *vf.oldTime().oldTime().internalField()*mesh().V00()
                    )/mesh().V()
                ),
                rDeltaT.value()*
                (
                    coefft.boundaryField()*vf.boundaryField() -
                    (
                        coefft0.boundaryField()*
                        rho.oldTime().boundaryField()*
                        vf.oldTime().boundaryField()
                      - coefft00.boundaryField()*
                        rho.oldTime().oldTime().boundaryField()*
                        vf.oldTime().oldTime().boundaryField()
                    )
                )
            )
        );
    }
    else
    {
        return tmp<volScalarField>
        (
            new volScalarField
            (
                ddtIOobject,
                rDeltaT*
                (
                    coefft*rho*vf
                  - coefft0*rho.oldTime()*vf.oldTime()
                  + coefft00*rho.oldTime().oldTime()*vf.oldTime().oldTime()
                )
            )
        );
    }
}


tmp<fvScalarMatrix>
boundedBackwardDdtScheme::fvmDdt
(
    volScalarField& vf
)
{
    tmp<fvScalarMatrix> tfvm
    (
        new fvScalarMatrix
        (
            vf,
            vf.dimensions()*dimVol/dimTime
        )
    );

    fvScalarMatrix& fvm = tfvm();

    scalar rDeltaT = 1.0/deltaT_();

    scalar deltaT = deltaT_();
    scalar deltaT0 = deltaT0_(vf);

    // Calculate unboundedness indicator
    // Note: all times moved by one because access to internal field
    // copies current field into the old-time level.
    scalarField phict =
        mag
        (
            vf.oldTime().oldTime().internalField()
          - vf.oldTime().oldTime().oldTime().internalField()
        )/
        (
            mag
            (
                vf.oldTime().internalField()
              - vf.oldTime().oldTime().internalField()
            )
            + VSMALL
        );

    scalarField limiter(pos(phict) - pos(phict - 1.0));

    scalarField coefft   = 1.0 + limiter*deltaT/(deltaT + deltaT0);
    scalarField coefft00 = limiter*deltaT*deltaT/(deltaT0*(deltaT + deltaT0));
    scalarField coefft0  = coefft + coefft00;

    fvm.diag() = (coefft*rDeltaT)*mesh().V();

    if (mesh().moving())
    {
        fvm.source() = rDeltaT*
        (
            coefft0*vf.oldTime().internalField()*mesh().V0()
          - coefft00*vf.oldTime().oldTime().internalField()
           *mesh().V00()
        );
    }
    else
    {
        fvm.source() = rDeltaT*mesh().V()*
        (
            coefft0*vf.oldTime().internalField()
          - coefft00*vf.oldTime().oldTime().internalField()
        );
    }

    return tfvm;
}


tmp<fvScalarMatrix>
boundedBackwardDdtScheme::fvmDdt
(
    const dimensionedScalar& rho,
    volScalarField& vf
)
{
    tmp<fvScalarMatrix> tfvm
    (
        new fvScalarMatrix
        (
            vf,
            rho.dimensions()*vf.dimensions()*dimVol/dimTime
        )
    );
    fvScalarMatrix& fvm = tfvm();

    scalar rDeltaT = 1.0/deltaT_();

    scalar deltaT = deltaT_();
    scalar deltaT0 = deltaT0_(vf);

    // Calculate unboundedness indicator
    // Note: all times moved by one because access to internal field
    // copies current field into the old-time level.
    scalarField phict =
        mag
        (
            vf.oldTime().oldTime().internalField()
          - vf.oldTime().oldTime().oldTime().internalField()
        )/
        (
            mag
            (
                vf.oldTime().internalField()
              - vf.oldTime().oldTime().internalField()
            )
            + VSMALL
        );

    scalarField limiter(pos(phict) - pos(phict - 1.0));

    scalarField coefft   = 1.0 + limiter*deltaT/(deltaT + deltaT0);
    scalarField coefft00 = limiter*deltaT*deltaT/(deltaT0*(deltaT + deltaT0));
    scalarField coefft0  = coefft + coefft00;

    fvm.diag() = (coefft*rDeltaT*rho.value())*mesh().V();

    if (mesh().moving())
    {
        fvm.source() = rDeltaT*rho.value()*
        (
            coefft0*vf.oldTime().internalField()*mesh().V0()
          - coefft00*vf.oldTime().oldTime().internalField()
           *mesh().V00()
        );
    }
    else
    {
        fvm.source() = rDeltaT*mesh().V()*rho.value()*
        (
            coefft0*vf.oldTime().internalField()
          - coefft00*vf.oldTime().oldTime().internalField()
        );
    }

    return tfvm;
}


tmp<fvScalarMatrix>
boundedBackwardDdtScheme::fvmDdt
(
    const volScalarField& rho,
    volScalarField& vf
)
{
    tmp<fvScalarMatrix> tfvm
    (
        new fvScalarMatrix
        (
            vf,
            rho.dimensions()*vf.dimensions()*dimVol/dimTime
        )
    );
    fvScalarMatrix& fvm = tfvm();

    scalar rDeltaT = 1.0/deltaT_();

    scalar deltaT = deltaT_();
    scalar deltaT0 = deltaT0_(vf);

    // Calculate unboundedness indicator
    // Note: all times moved by one because access to internal field
    // copies current field into the old-time level.
    scalarField phict =
        mag
        (
            rho.oldTime().oldTime().internalField()*
            vf.oldTime().oldTime().internalField()
          - rho.oldTime().oldTime().oldTime().internalField()*
            vf.oldTime().oldTime().oldTime().internalField()
        )/
        (
            mag
            (
                rho.oldTime().internalField()*
                vf.oldTime().internalField()
              - rho.oldTime().oldTime().internalField()*
                vf.oldTime().oldTime().internalField()
            )
            + VSMALL
        );

    scalarField limiter(pos(phict) - pos(phict - 1.0));

    scalarField coefft   = 1.0 + limiter*deltaT/(deltaT + deltaT0);
    scalarField coefft00 = limiter*deltaT*deltaT/(deltaT0*(deltaT + deltaT0));
    scalarField coefft0  = coefft + coefft00;

    fvm.diag() = (coefft*rDeltaT)*rho.internalField()*mesh().V();

    if (mesh().moving())
    {
        fvm.source() = rDeltaT*
        (
            coefft0*rho.oldTime().internalField()
           *vf.oldTime().internalField()*mesh().V0()
          - coefft00*rho.oldTime().oldTime().internalField()
           *vf.oldTime().oldTime().internalField()*mesh().V00()
        );
    }
    else
    {
        fvm.source() = rDeltaT*mesh().V()*
        (
            coefft0*rho.oldTime().internalField()
           *vf.oldTime().internalField()
          - coefft00*rho.oldTime().oldTime().internalField()
           *vf.oldTime().oldTime().internalField()
        );
    }

    return tfvm;
}


tmp<surfaceScalarField> boundedBackwardDdtScheme::fvcDdtPhiCorr
(
    const volScalarField& rA,
    const volScalarField& U,
    const surfaceScalarField& phi
)
{
    notImplemented
    (
        "boundedBackwardDdtScheme::fvcDdtPhiCorr"
    );

    return surfaceScalarField::null();
}


tmp<surfaceScalarField> boundedBackwardDdtScheme::fvcDdtPhiCorr
(
    const volScalarField& rA,
    const volScalarField& rho,
    const volScalarField& U,
    const surfaceScalarField& phi
)
{
    notImplemented
    (
        "boundedBackwardDdtScheme::fvcDdtPhiCorr"
    );

    return surfaceScalarField::null();
}


tmp<surfaceScalarField> boundedBackwardDdtScheme::meshPhi
(
    const volScalarField& vf
)
{
    notImplemented
    (
        "boundedBackwardDdtScheme::meshPhi(const volScalarField& vf)"
    );

    return surfaceScalarField::null();
}


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

} // End namespace fv

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

} // End namespace Foam

// ************************ vim: set sw=4 sts=4 et: ************************ //
