/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2011-2020 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/>.

Class
    Foam::motionDiffusivity

Description
    Abstract base class for cell-centre mesh motion diffusivity.

SourceFiles
    motionDiffusivity.C

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

#ifndef motionDiffusivity_H
#define motionDiffusivity_H

#include "surfaceFieldsFwd.H"
#include "fvMesh.H"

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

namespace Foam
{

/*---------------------------------------------------------------------------*\
                      Class motionDiffusivity Declaration
\*---------------------------------------------------------------------------*/

class motionDiffusivity
{
    // Private Data

        //- Mesh reference
        const fvMesh& mesh_;

public:

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


    // Declare run-time constructor selection tables

        declareRunTimeSelectionTable
        (
            autoPtr,
            motionDiffusivity,
            Istream,
            (
                const fvMesh& mesh,
                Istream& mdData
            ),
            (mesh, mdData)
        );


    // Selectors

        //- Select null constructed
        static autoPtr<motionDiffusivity> New
        (
            const fvMesh& mesh,
            Istream& mdData
        );


    // Constructors

        //- Construct for the given fvMesh
        motionDiffusivity(const fvMesh& mesh);


    //- Destructor
    virtual ~motionDiffusivity();


    // Member Functions

        //- Return reference to the mesh
        const fvMesh& mesh() const
        {
            return mesh_;
        }

        //- Correct the motion diffusivity
        virtual void correct()
        {}


    // Member Operators

        //- Return diffusivity field
        virtual tmp<surfaceScalarField> operator()() const = 0;
};


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

} // End namespace Foam

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

#endif

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