/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | www.openfoam.com
     \\/     M anipulation  |
-------------------------------------------------------------------------------
    Copyright (C) 2011-2016 OpenFOAM Foundation
-------------------------------------------------------------------------------
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/>.

Class
    Foam::UpwindFitScheme

Group
    grpFvSurfaceInterpolationSchemes

Description
    Upwind biased fit surface interpolation scheme that applies an explicit
    correction to linear.

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

#ifndef UpwindFitScheme_H
#define UpwindFitScheme_H

#include "UpwindFitData.H"
#include "linear.H"

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

namespace Foam
{

/*---------------------------------------------------------------------------*\
                           Class UpwindFitScheme Declaration
\*---------------------------------------------------------------------------*/

template<class Type, class Polynomial, class Stencil>
class UpwindFitScheme
:
    public linear<Type>
{
    // Private Data

        //- Reference to the surface flux used to choose upwind direction
        const surfaceScalarField& faceFlux_;

        //- Factor the fit is allowed to deviate from linear.
        //  This limits the amount of high-order correction and increases
        //  stability on bad meshes
        const scalar linearLimitFactor_;

        //- Weights for central stencil
        const scalar centralWeight_;


    // Private Member Functions

        //- No copy construct
        UpwindFitScheme(const UpwindFitScheme&) = delete;

        //- No copy assignment
        void operator=(const UpwindFitScheme&) = delete;


public:

    //- Runtime type information
    TypeName("UpwindFitScheme");


    // Constructors

        //- Construct from mesh and Istream
        //  The name of the flux field is read from the Istream and looked-up
        //  from the mesh objectRegistry
        UpwindFitScheme(const fvMesh& mesh, Istream& is)
        :
            linear<Type>(mesh),
            faceFlux_(mesh.lookupObject<surfaceScalarField>(word(is))),
            linearLimitFactor_(readScalar(is)),
            centralWeight_(1000)
        {}


        //- Construct from mesh, faceFlux and Istream
        UpwindFitScheme
        (
            const fvMesh& mesh,
            const surfaceScalarField& faceFlux,
            Istream& is
        )
        :
            linear<Type>(mesh),
            faceFlux_(faceFlux),
            linearLimitFactor_(readScalar(is)),
            centralWeight_(1000)
        {}


    // Member Functions

        //- Return true if this scheme uses an explicit correction
        virtual bool corrected() const
        {
            return true;
        }

        //- Return the explicit correction to the face-interpolate
        virtual tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
        correction
        (
            const GeometricField<Type, fvPatchField, volMesh>& vf
        ) const
        {
            const fvMesh& mesh = this->mesh();

            const extendedUpwindCellToFaceStencil& stencil = Stencil::New
            (
                mesh,
                false,          //pureUpwind
                scalar(0.5)
            );

            const UpwindFitData<Polynomial>& ufd =
            UpwindFitData<Polynomial>::New
            (
                mesh,
                stencil,
                true,           //calculate as offset to linear
                linearLimitFactor_,
                centralWeight_
            );

            const List<scalarList>& fo = ufd.owncoeffs();
            const List<scalarList>& fn = ufd.neicoeffs();

            return stencil.weightedSum(faceFlux_, vf, fo, fn);
        }
};


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

} // End namespace Foam

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

// Add the patch constructor functions to the hash tables

#define makeUpwindFitSurfaceInterpolationTypeScheme\
(                                                                              \
    SS,                                                                        \
    POLYNOMIAL,                                                                \
    STENCIL,                                                                   \
    TYPE                                                                       \
)                                                                              \
                                                                               \
typedef UpwindFitScheme<TYPE, POLYNOMIAL, STENCIL>                             \
    UpwindFitScheme##TYPE##POLYNOMIAL##STENCIL##_;                             \
defineTemplateTypeNameAndDebugWithName                                         \
    (UpwindFitScheme##TYPE##POLYNOMIAL##STENCIL##_, #SS, 0);                   \
                                                                               \
surfaceInterpolationScheme<TYPE>::addMeshConstructorToTable                    \
<UpwindFitScheme<TYPE, POLYNOMIAL, STENCIL>>                                   \
    add##SS##STENCIL##TYPE##MeshConstructorToTable_;                           \
                                                                               \
surfaceInterpolationScheme<TYPE>::addMeshFluxConstructorToTable                \
<UpwindFitScheme<TYPE, POLYNOMIAL, STENCIL>>                                   \
    add##SS##STENCIL##TYPE##MeshFluxConstructorToTable_;

#define makeUpwindFitSurfaceInterpolationScheme(SS, POLYNOMIAL, STENCIL)       \
                                                                               \
makeUpwindFitSurfaceInterpolationTypeScheme(SS,POLYNOMIAL,STENCIL,scalar)      \
makeUpwindFitSurfaceInterpolationTypeScheme(SS,POLYNOMIAL,STENCIL,vector)      \
makeUpwindFitSurfaceInterpolationTypeScheme                                    \
(                                                                              \
    SS,                                                                        \
    POLYNOMIAL,                                                                \
    STENCIL,                                                                   \
    sphericalTensor                                                            \
)                                                                              \
makeUpwindFitSurfaceInterpolationTypeScheme(SS,POLYNOMIAL,STENCIL,symmTensor) \
makeUpwindFitSurfaceInterpolationTypeScheme(SS,POLYNOMIAL,STENCIL,tensor)


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

#endif

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