/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2013 OpenFOAM Foundation
     \\/     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 "fvcReconstruct.H"
#include "fvMesh.H"
#include "zeroGradientFvPatchFields.H"

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

namespace Foam
{

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

namespace fvc
{

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


template<class Type>
tmp
<
    GeometricField
    <
        typename outerProduct<vector,Type>::type, fvPatchField, volMesh
    >
>
reconstruct
(
    const GeometricField<Type, fvsPatchField, surfaceMesh>& ssf
)
{
    typedef typename outerProduct<vector, Type>::type GradType;

    const fvMesh& mesh = ssf.mesh();

    surfaceVectorField faceVols
    (
        mesh.Sf()/(mesh.magSf()*mesh.nonOrthDeltaCoeffs())
    );
    
    const surfaceScalarField& weights = mesh.weights();
    
    volTensorField T(
        IOobject
            (
                "T",
                ssf.instance(),
                mesh,
                IOobject::NO_READ,
                IOobject::NO_WRITE
            ),
        mesh,
        dimensionedTensor("0", dimVolume, pTraits<tensor>::zero),
        "zeroGradient"
    );
    GeometricField <GradType, fvPatchField, volMesh> A(
        IOobject
            (
                "A",
                ssf.instance(),
                mesh,
                IOobject::NO_READ,
                IOobject::NO_WRITE
            ),
        mesh,
        dimensioned<GradType>("0", dimLength * ssf.dimensions(), pTraits<GradType>::zero),
        "zeroGradient"
    );
    const labelUList& owner = mesh.owner();
    const labelUList& neighbour = mesh.neighbour();
    forAll(faceVols, facei) {
        T[owner[facei]] += mesh.Sf()[facei] * faceVols[facei] * (1-weights[facei]);
        T[neighbour[facei]] += mesh.Sf()[facei] * faceVols[facei] * weights[facei];
        
        A[owner[facei]] += faceVols[facei] * ssf[facei]* (1-weights[facei]);
        A[neighbour[facei]] += faceVols[facei] * ssf[facei]* weights[facei];
    }
    forAll(faceVols.boundaryField(), patchi) {
        const vectorField& pSf = mesh.Sf().boundaryField()[patchi];
        const vectorField& pFaceVols = faceVols.boundaryField()[patchi];
        const scalarField& pWeights = weights.boundaryField()[patchi];
        const Field<Type>& pssf = ssf.boundaryField()[patchi];
        const labelUList& pFaceCells = mesh.boundary()[patchi].faceCells();
        
        forAll(faceVols.boundaryField()[patchi], facei) {
            tensor addT = pSf[facei] * pFaceVols[facei];
            GradType addA = pFaceVols[facei] * pssf[facei];
            if (faceVols.boundaryField()[patchi].coupled()) {
                addT *= (1-pWeights[facei]);
                addA *= (1-pWeights[facei]);
            }
            
            T[pFaceCells[facei]] += addT;
            A[pFaceCells[facei]] += addA;
        }
    }
    T.correctBoundaryConditions();
    A.correctBoundaryConditions();
            
    tmp<GeometricField<GradType, fvPatchField, volMesh> > treconField
    (
        new GeometricField<GradType, fvPatchField, volMesh>
        (
            IOobject
            (
                "volIntegrate("+ssf.name()+')',
                ssf.instance(),
                mesh,
                IOobject::NO_READ,
                IOobject::NO_WRITE
            ),
            inv(T) & A,
            zeroGradientFvPatchField<GradType>::typeName
        )
    );

    treconField().correctBoundaryConditions();

    return treconField;
}

template<class Type>
tmp
<
    GeometricField
    <
        typename outerProduct<vector, Type>::type, fvPatchField, volMesh
    >
>
reconstruct
(
    const tmp<GeometricField<Type, fvsPatchField, surfaceMesh> >& tssf
)
{
    typedef typename outerProduct<vector, Type>::type GradType;
    tmp<GeometricField<GradType, fvPatchField, volMesh> > tvf
    (
        fvc::reconstruct(tssf())
    );
    tssf.clear();
    return tvf;
}


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

} // End namespace fvc

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

} // End namespace Foam

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