/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright held by original author
     \\/     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 2 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, write to the Free Software Foundation,
    Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

\*---------------------------------------------------------------------------*/

#include "solidWallMixedTemperatureCoupledFvPatchScalarField.H"
#include "addToRunTimeSelectionTable.H"
#include "fvPatchFieldMapper.H"
#include "volFields.H"
#include "directMappedPatchBase.H"
#include "regionProperties.H"

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

Foam::solidWallMixedTemperatureCoupledFvPatchScalarField::
solidWallMixedTemperatureCoupledFvPatchScalarField
(
    const fvPatch& p,
    const DimensionedField<scalar, volMesh>& iF
)
:
    mixedFvPatchScalarField(p, iF),
    neighbourFieldName_("undefined-neighbourFieldName"),
    KName_("undefined-K")
{
    this->refValue() = 0.0;
    this->refGrad() = 0.0;
    this->valueFraction() = 1.0;
}


Foam::solidWallMixedTemperatureCoupledFvPatchScalarField::
solidWallMixedTemperatureCoupledFvPatchScalarField
(
    const solidWallMixedTemperatureCoupledFvPatchScalarField& ptf,
    const fvPatch& p,
    const DimensionedField<scalar, volMesh>& iF,
    const fvPatchFieldMapper& mapper
)
:
    mixedFvPatchScalarField(ptf, p, iF, mapper),
    neighbourFieldName_(ptf.neighbourFieldName_),
    KName_(ptf.KName_)
{}


Foam::solidWallMixedTemperatureCoupledFvPatchScalarField::
solidWallMixedTemperatureCoupledFvPatchScalarField
(
    const fvPatch& p,
    const DimensionedField<scalar, volMesh>& iF,
    const dictionary& dict
)
:
    mixedFvPatchScalarField(p, iF),
    neighbourFieldName_(dict.lookup("neighbourFieldName")),
    KName_(dict.lookup("K"))
{
    if (!isA<directMappedPatchBase>(this->patch().patch()))
    {
        FatalErrorIn
        (
            "solidWallMixedTemperatureCoupledFvPatchScalarField::"
            "solidWallMixedTemperatureCoupledFvPatchScalarField\n"
            "(\n"
            "    const fvPatch& p,\n"
            "    const DimensionedField<scalar, volMesh>& iF,\n"
            "    const dictionary& dict\n"
            ")\n"
        )   << "\n    patch type '" << p.type()
            << "' not type '" << directMappedPatchBase::typeName << "'"
            << "\n    for patch " << p.name()
            << " of field " << dimensionedInternalField().name()
            << " in file " << dimensionedInternalField().objectPath()
            << exit(FatalError);
    }

    fvPatchScalarField::operator=(scalarField("value", dict, p.size()));

    if (dict.found("refValue"))
    {
        // Full restart
        refValue() = scalarField("refValue", dict, p.size());
        refGrad() = scalarField("refGradient", dict, p.size());
        valueFraction() = scalarField("valueFraction", dict, p.size());
    }
    else
    {
        // Start from user entered data. Assume fixedValue.
        refValue() = *this;
        refGrad() = 0.0;
        valueFraction() = 1.0;
    }
}


Foam::solidWallMixedTemperatureCoupledFvPatchScalarField::
solidWallMixedTemperatureCoupledFvPatchScalarField
(
    const solidWallMixedTemperatureCoupledFvPatchScalarField& wtcsf,
    const DimensionedField<scalar, volMesh>& iF
)
:
    mixedFvPatchScalarField(wtcsf, iF),
    neighbourFieldName_(wtcsf.neighbourFieldName_),
    KName_(wtcsf.KName_)
{}


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

const Foam::fvPatchScalarField&
Foam::solidWallMixedTemperatureCoupledFvPatchScalarField::K() const
{
    return this->patch().lookupPatchField<volScalarField, scalar>(KName_);
}


void Foam::solidWallMixedTemperatureCoupledFvPatchScalarField::updateCoeffs()
{
    if (updated())
    {
        return;
    }

    // Get the coupling information from the directMappedPatchBase
    const directMappedPatchBase& mpp = refCast<const directMappedPatchBase>
    (
        patch().patch()
    );
    const polyMesh& nbrMesh = mpp.sampleMesh();
    const fvPatch& nbrPatch = refCast<const fvMesh>
    (
        nbrMesh
    ).boundary()[mpp.samplePolyPatch().index()];

    // Force recalculation of mapping and schedule
    const mapDistribute& distMap = mpp.map();

    tmp<scalarField> intFld = patchInternalField();


    const solidWallMixedTemperatureCoupledFvPatchScalarField& nbrField =
    refCast<const solidWallMixedTemperatureCoupledFvPatchScalarField>
    (
        nbrPatch.lookupPatchField<volScalarField, scalar>
        (
            neighbourFieldName_
        )
    );

    // Swap to obtain full local values of neighbour internal field
    scalarField nbrIntFld = nbrField.patchInternalField();
    mapDistribute::distribute
    (
        Pstream::defaultCommsType,
        distMap.schedule(),
        distMap.constructSize(),
        distMap.subMap(),           // what to send
        distMap.constructMap(),     // what to receive
        nbrIntFld
    );

    // Swap to obtain full local values of neighbour K*delta
    scalarField nbrKDelta = nbrField.K()*nbrPatch.deltaCoeffs();
    mapDistribute::distribute
    (
        Pstream::defaultCommsType,
        distMap.schedule(),
        distMap.constructSize(),
        distMap.subMap(),           // what to send
        distMap.constructMap(),     // what to receive
        nbrKDelta
    );

    tmp<scalarField> myKDelta = K()*patch().deltaCoeffs();


    // Both sides agree on
    // - temperature : (myKDelta*fld + nbrKDelta*nbrFld)/(myKDelta+nbrKDelta)
    // - gradient    : (temperature-fld)*delta
    // We've got a degree of freedom in how to implement this in a mixed bc.
    // (what gradient, what fixedValue and mixing coefficient)
    // Two reasonable choices:
    // 1. specify above temperature on one side (preferentially the high side)
    //    and above gradient on the other. So this will switch between pure
    //    fixedvalue and pure fixedgradient
    // 2. specify gradient and temperature such that the equations are the
    //    same on both sides. This leads to the choice of
    //    - refGradient = zero gradient
    //    - refValue = neighbour value
    //    - mixFraction = nbrKDelta / (nbrKDelta + myKDelta())


    this->refValue() = nbrIntFld;

    this->refGrad() = 0.0;

    this->valueFraction() = nbrKDelta / (nbrKDelta + myKDelta());

    mixedFvPatchScalarField::updateCoeffs();


    if (debug)
    {
        scalar Q = gSum(K()*patch().magSf()*snGrad());

        Info<< patch().boundaryMesh().mesh().name() << ':'
            << patch().name() << ':'
            << this->dimensionedInternalField().name() << " -> "
            << nbrMesh.name() << ':'
            << nbrPatch.name() << ':'
            << this->dimensionedInternalField().name() << " :"
            << " heatFlux:" << Q
            << " walltemperature "
            << " min:" << gMin(*this)
            << " max:" << gMax(*this)
            << " avg:" << gAverage(*this)
            << endl;
    }
}


void Foam::solidWallMixedTemperatureCoupledFvPatchScalarField::write
(
    Ostream& os
) const
{
    mixedFvPatchScalarField::write(os);
    os.writeKeyword("neighbourFieldName")<< neighbourFieldName_
        << token::END_STATEMENT << nl;
    os.writeKeyword("K") << KName_ << token::END_STATEMENT << nl;
}


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

namespace Foam
{

makePatchTypeField
(
    fvPatchScalarField,
    solidWallMixedTemperatureCoupledFvPatchScalarField
);

} // End namespace Foam

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