/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2011-2026 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 "fvMesh.H"
#include "volFields.H"
#include "surfaceFields.H"
#include "pointFields.H"
#include "slicedVolFields.H"
#include "slicedSurfaceFields.H"
#include "SubField.H"
#include "demandDrivenData.H"
#include "zonesGenerator.H"
#include "fvMeshLduAddressing.H"
#include "fvMeshTopoChanger.H"
#include "fvMeshDistributor.H"
#include "fvMeshMover.H"
#include "fvMeshStitcher.H"
#include "nonConformalFvPatch.H"
#include "polyFacesFvsPatchLabelField.H"
#include "polyTopoChangeMap.H"
#include "MapFvFields.H"
#include "fvMeshMapper.H"
#include "pointMesh.H"
#include "pointMeshMapper.H"
#include "MapPointField.H"
#include "meshObjects.H"
#include "HashPtrTable.H"
#include "CompactListList.H"

#include "fvcSurfaceIntegrate.H"
#include "fvcReconstruct.H"
#include "surfaceInterpolate.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
    defineTypeNameAndDebug(fvMesh, 0);
}

const Foam::HashSet<Foam::word> Foam::fvMesh::geometryFields
{
    "Vc",
    "Vc0",
    "Vc00",
    "Sf",
    "magSf",
    "Cc",
    "Cf",
    "meshPhi",
    "meshPhi_0"
};

const Foam::HashSet<Foam::word> Foam::fvMesh::curGeometryFields
{
    "Vc",
    "Sf",
    "magSf",
    "Cc",
    "Cf"
};


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

void Foam::fvMesh::clearFvGeomNotOldVol()
{
    DebugInFunction << "Clearing current-time FV geometry" << endl;

    meshObjects::clearUpto
    <
        fvMesh,
        DeletableMeshObject,
        MoveableMeshObject
    >(*this);

    meshObjects::clearUpto
    <
        lduMesh,
        DeletableMeshObject,
        MoveableMeshObject
    >(*this);

    deleteDemandDrivenData(VPtr_);
    deleteDemandDrivenData(SfSlicePtr_);
    deleteDemandDrivenData(SfPtr_);
    deleteDemandDrivenData(magSfSlicePtr_);
    deleteDemandDrivenData(magSfPtr_);
    deleteDemandDrivenData(CSlicePtr_);
    deleteDemandDrivenData(CPtr_);
    deleteDemandDrivenData(CfSlicePtr_);
    deleteDemandDrivenData(CfPtr_);
}


void Foam::fvMesh::clearFvGeom()
{
    DebugInFunction << "Clearing FV Geometry" << endl;

    clearFvGeomNotOldVol();

    deleteDemandDrivenData(phiPtr_);
    deleteDemandDrivenData(V0Ptr_);
    deleteDemandDrivenData(V00Ptr_);
}


void Foam::fvMesh::updateGeomNotOldVol()
{
    bool haveV = (VPtr_ != nullptr);
    bool haveSf = (SfSlicePtr_ != nullptr || SfPtr_ != nullptr);
    bool haveMagSf = (magSfSlicePtr_ != nullptr || magSfPtr_ != nullptr);
    bool haveCP = (CSlicePtr_ != nullptr || CPtr_ != nullptr);
    bool haveCf = (CfSlicePtr_ != nullptr || CfPtr_ != nullptr);

    clearFvGeomNotOldVol();

    // Now recreate the fields
    if (haveV)
    {
        (void)V();
    }
    if (haveSf)
    {
        (void)Sf();
    }
    if (haveMagSf)
    {
        (void)magSf();
    }
    if (haveCP)
    {
        (void)C();
    }
    if (haveCf)
    {
        (void)Cf();
    }
}


void Foam::fvMesh::storeOldTimeFields()
{
    storeOldTimeFields<PointField>();
    storeOldTimeFields<VolField>();
    storeOldTimeFields<SurfaceField>();
}


void Foam::fvMesh::nullOldestTimeFields()
{
    nullOldestTimeFields<PointField>();
    nullOldestTimeFields<VolField>();
    nullOldestTimeFields<SurfaceField>();
}


void Foam::fvMesh::printAllocated() const
{
    polyMesh::printAllocated();

    Pout<< "fvMesh allocated :" << endl;

    if (lduPtr_)
    {
        Pout<< "    Ldu Addressing" << endl;
    }

    if (polyFacesBfPtr_)
    {
        Pout<< "    Poly-faces boundary field" << endl;
    }

    if (polyBFacePatchesPtr_)
    {
        Pout<< "    Poly-boundary-face to fv-patch and fv-patch-face map"
            << endl;
    }

    if (ownerBfPtr_)
    {
        Pout<< "    Owner boundary field" << endl;
    }

    if (V0Ptr_)
    {
        Pout<< "    Old-time cell volumes field" << endl;
    }

    if (V00Ptr_)
    {
        Pout<< "    Old-old-time cell volumes field" << endl;
    }

    if (SfPtr_)
    {
        Pout<< "    Non-sliced face areas field" << endl;
    }

    if (magSfPtr_)
    {
        Pout<< "    Non-sliced face area magnitudes field" << endl;
    }

    if (CPtr_)
    {
        Pout<< "    Non-sliced cell centres field" << endl;
    }

    if (CfPtr_)
    {
        Pout<< "    Non-sliced face centres field" << endl;
    }

    if (phiPtr_)
    {
        Pout<< "    Mesh flux field" << endl;
    }

    surfaceInterpolation::printAllocated();
}


void Foam::fvMesh::clearGeom()
{
    DebugInFunction << "Clearing geometry" << endl;

    clearFvGeom();

    polyMesh::clearGeom();
}


void Foam::fvMesh::clearAddressing(const bool isMeshUpdate)
{
    DebugInFunction << "isMeshUpdate: " << isMeshUpdate << endl;

    if (isMeshUpdate)
    {
        // Part of a mesh update. Keep meshObjects that have an topoChange
        // callback
        meshObjects::clearUpto
        <
            fvMesh,
            DeletableMeshObject,
            TopoChangeableMeshObject
        >
        (
            *this
        );
        meshObjects::clearUpto
        <
            lduMesh,
            DeletableMeshObject,
            TopoChangeableMeshObject
        >
        (
            *this
        );
    }
    else
    {
        meshObjects::clear<fvMesh, DeletableMeshObject>(*this);
        meshObjects::clear<lduMesh, DeletableMeshObject>(*this);
    }

    deleteDemandDrivenData(lduPtr_);
    deleteDemandDrivenData(polyFacesBfIOPtr_);
    deleteDemandDrivenData(polyFacesBfPtr_);
    deleteDemandDrivenData(polyBFaceOffsetsPtr_);
    deleteDemandDrivenData(polyBFaceOffsetPatchesPtr_);
    deleteDemandDrivenData(polyBFaceOffsetPatchFacesPtr_);
    deleteDemandDrivenData(polyBFacePatchesPtr_);
    deleteDemandDrivenData(polyBFacePatchFacesPtr_);
    deleteDemandDrivenData(ownerBfPtr_);
}


void Foam::fvMesh::clearOut()
{
    clearFvGeom();

    surfaceInterpolation::clearOut();

    clearAddressing();

    polyMesh::clearOut();
}


Foam::wordList Foam::fvMesh::polyFacesPatchTypes() const
{
    wordList wantedPatchTypes
    (
        boundary().size(),
        polyFacesFvsPatchLabelField::typeName
    );

    forAll(boundary(), patchi)
    {
        const fvPatch& fvp = boundary()[patchi];

        if (isA<nonConformalFvPatch>(fvp))
        {
            wantedPatchTypes[patchi] =
                refCast<const nonConformalFvPatch>(fvp).polyFacesType();
        }
    }

    return wantedPatchTypes;
}


Foam::surfaceLabelField::Boundary& Foam::fvMesh::polyFacesBfRef()
{
    if (!polyFacesBfPtr_)
    {
        polyFacesBf();
    }

    setPolyFacesBfInstance(time().name());

    return *polyFacesBfPtr_;
}


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

Foam::fvMesh::fvMesh
(
    const IOobject& io,
    const bool doPost
    // const bool doZones
)
:
    polyMesh(io),
    surfaceMesh(*this),
    surfaceInterpolation(*this),
    boundary_(*this, poly().boundary()),
    stitcher_(nullptr),
    topoChanger_(nullptr),
    distributor_(nullptr),
    mover_(nullptr),
    lduPtr_(nullptr),
    polyFacesBfIOPtr_(nullptr),
    polyFacesBfPtr_(nullptr),
    polyBFaceOffsetsPtr_(nullptr),
    polyBFaceOffsetPatchesPtr_(nullptr),
    polyBFaceOffsetPatchFacesPtr_(nullptr),
    polyBFacePatchesPtr_(nullptr),
    polyBFacePatchFacesPtr_(nullptr),
    ownerBfPtr_(nullptr),
    curTimeIndex_(time().timeIndex()),
    VPtr_(nullptr),
    V0Ptr_(nullptr),
    V00Ptr_(nullptr),
    SfSlicePtr_(nullptr),
    SfPtr_(nullptr),
    magSfSlicePtr_(nullptr),
    magSfPtr_(nullptr),
    CSlicePtr_(nullptr),
    CPtr_(nullptr),
    CfSlicePtr_(nullptr),
    CfPtr_(nullptr),
    phiPtr_(nullptr)
{
    DebugInFunction << "Constructing fvMesh from IOobject" << endl;

    if (doPost)
    {
        postConstruct(true, true, stitchType::geometric);
    }
}


Foam::fvMesh::fvMesh
(
    const IOobject& io,
    pointField&& points,
    const cellShapeList& shapes,
    const faceListList& boundaryFaces,
    const wordList& boundaryPatchNames,
    const PtrList<dictionary>& boundaryDicts,
    const word& defaultBoundaryPatchName,
    const word& defaultBoundaryPatchType,
    const bool syncPar
)
:
    polyMesh
    (
        io,
        std::move(points),
        shapes,
        boundaryFaces,
        boundaryPatchNames,
        boundaryDicts,
        defaultBoundaryPatchName,
        defaultBoundaryPatchType,
        syncPar
    ),
    surfaceMesh(*this),
    surfaceInterpolation(*this),
    boundary_(*this, poly().boundary()),
    stitcher_(nullptr),
    topoChanger_(nullptr),
    distributor_(nullptr),
    mover_(nullptr),
    lduPtr_(nullptr),
    polyFacesBfIOPtr_(nullptr),
    polyFacesBfPtr_(nullptr),
    polyBFaceOffsetsPtr_(nullptr),
    polyBFaceOffsetPatchesPtr_(nullptr),
    polyBFaceOffsetPatchFacesPtr_(nullptr),
    polyBFacePatchesPtr_(nullptr),
    polyBFacePatchFacesPtr_(nullptr),
    ownerBfPtr_(nullptr),
    curTimeIndex_(time().timeIndex()),
    VPtr_(nullptr),
    V0Ptr_(nullptr),
    V00Ptr_(nullptr),
    SfSlicePtr_(nullptr),
    SfPtr_(nullptr),
    magSfSlicePtr_(nullptr),
    magSfPtr_(nullptr),
    CSlicePtr_(nullptr),
    CPtr_(nullptr),
    CfSlicePtr_(nullptr),
    CfPtr_(nullptr),
    phiPtr_(nullptr)
{
    DebugInFunction << "Constructing fvMesh from shapes" << endl;
}


Foam::fvMesh::fvMesh
(
    const IOobject& io,
    pointField&& points,
    faceList&& faces,
    labelList&& allOwner,
    labelList&& allNeighbour,
    const bool syncPar
)
:
    polyMesh
    (
        io,
        std::move(points),
        std::move(faces),
        std::move(allOwner),
        std::move(allNeighbour),
        syncPar
    ),
    surfaceMesh(*this),
    surfaceInterpolation(*this),
    boundary_(*this, poly().boundary()),
    stitcher_(nullptr),
    topoChanger_(nullptr),
    distributor_(nullptr),
    mover_(nullptr),
    lduPtr_(nullptr),
    polyFacesBfIOPtr_(nullptr),
    polyFacesBfPtr_(nullptr),
    polyBFaceOffsetsPtr_(nullptr),
    polyBFaceOffsetPatchesPtr_(nullptr),
    polyBFaceOffsetPatchFacesPtr_(nullptr),
    polyBFacePatchesPtr_(nullptr),
    polyBFacePatchFacesPtr_(nullptr),
    ownerBfPtr_(nullptr),
    curTimeIndex_(time().timeIndex()),
    VPtr_(nullptr),
    V0Ptr_(nullptr),
    V00Ptr_(nullptr),
    SfSlicePtr_(nullptr),
    SfPtr_(nullptr),
    magSfSlicePtr_(nullptr),
    magSfPtr_(nullptr),
    CSlicePtr_(nullptr),
    CPtr_(nullptr),
    CfSlicePtr_(nullptr),
    CfPtr_(nullptr),
    phiPtr_(nullptr)
{
    DebugInFunction << "Constructing fvMesh from components" << endl;
}


Foam::fvMesh::fvMesh
(
    const IOobject& io,
    pointField&& points,
    faceList&& faces,
    cellList&& cells,
    const bool syncPar
)
:
    polyMesh
    (
        io,
        std::move(points),
        std::move(faces),
        std::move(cells),
        syncPar
    ),
    surfaceMesh(*this),
    surfaceInterpolation(*this),
    boundary_(*this),
    stitcher_(nullptr),
    topoChanger_(nullptr),
    distributor_(nullptr),
    mover_(nullptr),
    lduPtr_(nullptr),
    polyFacesBfIOPtr_(nullptr),
    polyFacesBfPtr_(nullptr),
    polyBFaceOffsetsPtr_(nullptr),
    polyBFaceOffsetPatchesPtr_(nullptr),
    polyBFaceOffsetPatchFacesPtr_(nullptr),
    polyBFacePatchesPtr_(nullptr),
    polyBFacePatchFacesPtr_(nullptr),
    ownerBfPtr_(nullptr),
    curTimeIndex_(time().timeIndex()),
    VPtr_(nullptr),
    V0Ptr_(nullptr),
    V00Ptr_(nullptr),
    SfSlicePtr_(nullptr),
    SfPtr_(nullptr),
    magSfSlicePtr_(nullptr),
    magSfPtr_(nullptr),
    CSlicePtr_(nullptr),
    CPtr_(nullptr),
    CfSlicePtr_(nullptr),
    CfPtr_(nullptr),
    phiPtr_(nullptr)
{
    DebugInFunction << "Constructing fvMesh from components" << endl;
}


Foam::fvMesh::fvMesh(fvMesh&& mesh)
:
    polyMesh(Foam::move(mesh)),
    surfaceMesh(*this),
    surfaceInterpolation(Foam::move(mesh)),
    boundary_(Foam::move(mesh.boundary_)),
    stitcher_(Foam::move(mesh.stitcher_)),
    topoChanger_(Foam::move(mesh.topoChanger_)),
    distributor_(Foam::move(mesh.distributor_)),
    mover_(Foam::move(mesh.mover_)),
    lduPtr_(Foam::move(mesh.lduPtr_)),
    polyFacesBfIOPtr_(Foam::move(mesh.polyFacesBfIOPtr_)),
    polyFacesBfPtr_(Foam::move(mesh.polyFacesBfPtr_)),
    polyBFaceOffsetsPtr_(Foam::move(mesh.polyBFaceOffsetsPtr_)),
    polyBFaceOffsetPatchesPtr_(Foam::move(mesh.polyBFaceOffsetPatchesPtr_)),
    polyBFaceOffsetPatchFacesPtr_
    (
        Foam::move(mesh.polyBFaceOffsetPatchFacesPtr_)
    ),
    polyBFacePatchesPtr_(Foam::move(mesh.polyBFacePatchesPtr_)),
    polyBFacePatchFacesPtr_(Foam::move(mesh.polyBFacePatchFacesPtr_)),
    ownerBfPtr_(Foam::move(mesh.ownerBfPtr_)),
    curTimeIndex_(mesh.curTimeIndex_),
    VPtr_(Foam::move(mesh.VPtr_)),
    V0Ptr_(Foam::move(mesh.V0Ptr_)),
    V00Ptr_(Foam::move(mesh.V00Ptr_)),
    SfSlicePtr_(Foam::move(mesh.SfSlicePtr_)),
    SfPtr_(Foam::move(mesh.SfPtr_)),
    magSfSlicePtr_(Foam::move(mesh.magSfSlicePtr_)),
    magSfPtr_(Foam::move(mesh.magSfPtr_)),
    CSlicePtr_(Foam::move(mesh.CSlicePtr_)),
    CPtr_(Foam::move(mesh.CPtr_)),
    CfSlicePtr_(Foam::move(mesh.CfSlicePtr_)),
    CfPtr_(Foam::move(mesh.CfPtr_)),
    phiPtr_(Foam::move(mesh.phiPtr_))
{
    DebugInFunction << "Move-constructing fvMesh" << endl;
}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

Foam::fvMesh::~fvMesh()
{
    clearOut();
}


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

void Foam::fvMesh::postConstruct
(
    const bool changers,
    const bool zones,
    const stitchType stitch
)
{
    // Construct the stitcher
    stitcher_.set(fvMeshStitcher::New(*this, changers).ptr());

    // Stitch or Re-stitch if necessary
    if (stitch != stitchType::none)
    {
        stitcher_->connect(false, stitch == stitchType::geometric, true);
    }

    // Construct changers
    if (changers)
    {
        topoChanger_.set(fvMeshTopoChanger::New(*this).ptr());
        distributor_.set(fvMeshDistributor::New(*this).ptr());
        mover_.set(fvMeshMover::New(*this).ptr());

        // Check the existence of the cell volumes and read if present
        // and set the storage of V00
        if (fileHandler().isFile(time().timePath()/"Vc0"))
        {
            V0Ptr_ = new DimensionedField<scalar, fvMesh>
            (
                IOobject
                (
                    "Vc0",
                    time().name(),
                    *this,
                    IOobject::MUST_READ,
                    IOobject::NO_WRITE,
                    true
                ),
                *this,
                dimensions::volume
            );

            V00();
        }

        // Check the existence of the mesh fluxes and read if present
        if (fileHandler().isFile(time().timePath()/"meshPhi"))
        {
            phiPtr_ = new surfaceScalarField
            (
                IOobject
                (
                    "meshPhi",
                    time().name(),
                    *this,
                    IOobject::MUST_READ,
                    IOobject::NO_WRITE,
                    true
                ),
                *this,
                dimensions::volumetricFlux
            );
        }
    }

    // Generate the zones after the mesh manipulators have been constructed
    // to support motion-specific zone generators requiring access to the mover
    if (zones)
    {
        zonesGenerator::New(*this);
    }
}


bool Foam::fvMesh::topoChanging() const
{
    return topoChanger_.valid() && topoChanger_->dynamic();
}


bool Foam::fvMesh::distributing() const
{
    return distributor_.valid() && distributor_->dynamic();
}


bool Foam::fvMesh::dynamic() const
{
    return
        (topoChanger_.valid() && topoChanger_->dynamic())
     || (mover_.valid() && mover_->dynamic());
}


bool Foam::fvMesh::update()
{
    if
    (
        stitcher_->stitches()
     || topoChanger_->dynamic()
     || distributor_->dynamic()
    )
    {
        nullOldestTimeFields();
    }

    // Remove the oldest cell volume field
    if (V00Ptr_)
    {
        nullDemandDrivenData(V00Ptr_);
    }
    else
    {
        nullDemandDrivenData(V0Ptr_);
    }

    // Remove the oldest mesh flux field
    if (phiPtr_)
    {
        phiPtr_->nullOldestTime();
    }

    // Set topoChanged_ false before any mesh change. Topo-changing can switch
    // on and off during a run.
    topoChanged_ = false;

    topoChanged_ = topoChanger_->update();

    const bool distributed = distributor_->update();

    return topoChanged_ || distributed;
}


bool Foam::fvMesh::move()
{
    // Do not set moving_ false before any mesh motion. Once the mesh starts
    // moving it is considered to be moving for the rest of the run.
    const bool moved = mover_->update();

    curTimeIndex_ = time().timeIndex();

    stitcher_->connect(true, true, false);

    return moved;
}


void Foam::fvMesh::addFvPatches
(
    const List<polyPatch*>& p,
    const bool validBoundary
)
{
    if (boundary().size())
    {
        FatalErrorInFunction
            << " boundary already exists"
            << abort(FatalError);
    }

    // first add polyPatches
    addPatches(p, validBoundary);
    boundary_.addPatches(poly().boundary());
}


void Foam::fvMesh::removeFvBoundary()
{
    DebugInFunction << "Removing boundary patches." << endl;

    // Remove fvBoundaryMesh data first.
    boundary_.clear();
    boundary_.setSize(0);
    polyMesh::removeBoundary();

    clearOut();
}


void Foam::fvMesh::swap(fvMesh& otherMesh)
{
    // Clear the sliced fields
    clearFvGeom();

    // Clear the current volume and other geometry factors
    surfaceInterpolation::clearOut();

    // Clear any non-updateable addressing
    clearAddressing(true);

    polyMesh::swap(otherMesh);

    auto updatePatches = []
    (
        const polyPatchList& patches,
        fvBoundaryMesh& boundaryMesh
    )
    {
        boundaryMesh.setSize(patches.size());

        forAll(patches, patchi)
        {
            // Construct new processor patches, as the decomposition may have
            // changed. Leave other patches as is.

            if (isA<processorPolyPatch>(patches[patchi]))
            {
                boundaryMesh.set
                (
                    patchi,
                    fvPatch::New
                    (
                        patches[patchi],
                        boundaryMesh
                    )
                );
            }
        }
    };

    updatePatches(poly().boundary(), boundary_);
    updatePatches(otherMesh.poly().boundary(), otherMesh.boundary_);
}


Foam::fvMesh::readUpdateState Foam::fvMesh::readUpdate
(
    const stitchType stitch
)
{
    // Determine if this update moves forward in time. If so, searching back in
    // time for data files will only go back as far as the previous instance.
    const fileName instance0 = instance();
    const bool forward = readUpdateIsForward();

    // Update the polyMesh and the mesh instance
    const polyMesh::readUpdateState state = polyMesh::readUpdate();

    DebugInFunction << "Updating the fvMesh:" << endl;

    if (debug)
    {
        switch (state)
        {
            case polyMesh::TOPO_PATCH_CHANGE:
                Info<< "    Boundary and topological change" << endl;
                break;
            case polyMesh::TOPO_CHANGE:
                Info<< "    Topological change" << endl;
                break;
            case polyMesh::POINTS_MOVED:
                Info<< "    Point motion" << endl;
                break;
            default:
                Info<< "    No change" << endl;
                break;
        }
    }

    const bool reStitch =
        stitcher_.valid()
     && stitcher_->stitches()
     && stitch != stitchType::none
     && (
            !conformal()
         || time().findInstance
            (
                dbDir()/typeName,
                "polyFaces",
                IOobject::READ_IF_PRESENT,
                forward ? word(instance0) : word::null
            )
         != (forward ? instance0 : polyFacesBfIOPtr_->instance())
        );

    if (reStitch)
    {
        stitcher_->disconnect(false, false);
    }
    else if (state != polyMesh::UNCHANGED)
    {
        conform();
    }

    switch (state)
    {
        case polyMesh::TOPO_PATCH_CHANGE:
            boundary_.readUpdate(poly().boundary());
            clearOut();
            break;
        case polyMesh::TOPO_CHANGE:
            clearOut();
            break;
        case polyMesh::POINTS_MOVED:
            clearFvGeom();
            break;
        default:
            break;
    }

    if (reStitch && stitch != stitchType::none)
    {
        stitcher_->connect(false, stitch == stitchType::geometric, true);
    }

    // Return the corresponding fvMesh read update state
    switch (state)
    {
        case polyMesh::UNCHANGED:
            return reStitch ? STITCHED : UNCHANGED;
        case polyMesh::POINTS_MOVED:
            return reStitch ? STITCHED : POINTS_MOVED;
        case polyMesh::TOPO_CHANGE:
            return TOPO_CHANGE;
        case polyMesh::TOPO_PATCH_CHANGE:
            return TOPO_PATCH_CHANGE;
    }

    return UNCHANGED;
}


const Foam::fvBoundaryMesh& Foam::fvMesh::boundary() const
{
    return boundary_;
}


const Foam::lduAddressing& Foam::fvMesh::lduAddr() const
{
    if (!lduPtr_)
    {
        lduPtr_ = new fvMeshLduAddressing(*this);
    }

    return *lduPtr_;
}


bool Foam::fvMesh::conformal() const
{
    return !(polyFacesBfPtr_ && SfPtr_);
}


const Foam::surfaceLabelField::Boundary& Foam::fvMesh::polyFacesBf() const
{
    if (!polyFacesBfPtr_)
    {
        polyFacesBfIOPtr_ =
            new IOobject
            (
                "polyFaces",
                facesInstance(),
                typeName,
                *this,
                IOobject::NO_READ,
                IOobject::NO_WRITE,
                false
            );

        polyFacesBfPtr_ =
            new surfaceLabelField::Boundary
            (
                boundary(),
                surfaceLabelField::null(),
                polyFacesPatchTypes(),
                poly().boundary().types()
            );
    }

    return *polyFacesBfPtr_;
}


const Foam::UCompactListList<Foam::label>&
Foam::fvMesh::polyBFacePatches() const
{
    if (!polyBFacePatchesPtr_)
    {
        const label nPolyBFaces = nFaces() - nInternalFaces();

        // Count face-poly-bFaces to get the offsets
        polyBFaceOffsetsPtr_ = new labelList(nPolyBFaces + 1, 0);
        labelList& offsets = *polyBFaceOffsetsPtr_;
        forAll(boundary(), patchi)
        {
            forAll(boundary()[patchi], patchFacei)
            {
                const label polyBFacei =
                    (
                        polyFacesBfPtr_
                      ? (*polyFacesBfPtr_)[patchi][patchFacei]
                      : boundary()[patchi].start() + patchFacei
                    )
                  - nInternalFaces();

                offsets[polyBFacei + 1] ++;
            }
        }
        for (label polyBFacei = 0; polyBFacei < nPolyBFaces; ++ polyBFacei)
        {
            offsets[polyBFacei + 1] += offsets[polyBFacei];
        }

        // Set the poly-bFace patches and patch-faces, using the offsets as
        // counters
        polyBFaceOffsetPatchesPtr_ = new labelList(offsets.last());
        polyBFaceOffsetPatchFacesPtr_ = new labelList(offsets.last());
        labelUList& patches = *polyBFaceOffsetPatchesPtr_;
        labelUList& patchFaces = *polyBFaceOffsetPatchFacesPtr_;
        forAll(boundary(), patchi)
        {
            forAll(boundary()[patchi], patchFacei)
            {
                const label polyBFacei =
                    (
                        polyFacesBfPtr_
                      ? (*polyFacesBfPtr_)[patchi][patchFacei]
                      : boundary()[patchi].start() + patchFacei
                    )
                  - nInternalFaces();
                patches[offsets[polyBFacei]] = patchi;
                patchFaces[offsets[polyBFacei]] = patchFacei;
                offsets[polyBFacei] ++;
            }
        }

        // Restore the offsets by removing the count
        for
        (
            label polyBFacei = nPolyBFaces - 1;
            polyBFacei >= 0;
            -- polyBFacei
        )
        {
            offsets[polyBFacei + 1] = offsets[polyBFacei];
        }
        offsets[0] = 0;

        // List-lists
        polyBFacePatchesPtr_ =
            new UCompactListList<label>(offsets, patches);
        polyBFacePatchFacesPtr_ =
            new UCompactListList<label>(offsets, patchFaces);
    }

    return *polyBFacePatchesPtr_;
}


const Foam::UCompactListList<Foam::label>&
Foam::fvMesh::polyBFacePatchFaces() const
{
    if (!polyBFacePatchFacesPtr_)
    {
        polyBFacePatches();
    }

    return *polyBFacePatchFacesPtr_;
}


const Foam::surfaceLabelField::Boundary& Foam::fvMesh::ownerBf() const
{
    if (!ownerBfPtr_)
    {
        ownerBfPtr_ =
            new surfaceLabelField::Boundary
            (
                boundary(),
                surfaceLabelField::null(),
                wordList
                (
                    boundary().size(),
                    calculatedFvsPatchLabelField::typeName
                ),
                poly().boundary().types()
            );

        forAll(boundary(), patchi)
        {
            (*ownerBfPtr_)[patchi] =
                labelField(faceOwner(), polyFacesBf()[patchi]);
        }
    }

    return *ownerBfPtr_;
}


const Foam::fvMeshStitcher& Foam::fvMesh::stitcher() const
{
    return stitcher_();
}


Foam::fvMeshStitcher& Foam::fvMesh::stitcher()
{
    return stitcher_();
}


const Foam::fvMeshTopoChanger& Foam::fvMesh::topoChanger() const
{
    return topoChanger_();
}


const Foam::fvMeshDistributor& Foam::fvMesh::distributor() const
{
    return distributor_();
}


const Foam::fvMeshMover& Foam::fvMesh::mover() const
{
    return mover_();
}


void Foam::fvMesh::mapFields(const polyTopoChangeMap& map)
{
    DebugInFunction
        << " nOldCells:" << map.nOldCells()
        << " nCells:" << nCells()
        << " nOldFaces:" << map.nOldFaces()
        << " nFaces:" << nFaces()
        << endl;

    // We require geometric properties valid for the old mesh
    if
    (
        map.cellMap().size() != nCells()
     || map.faceMap().size() != nFaces()
    )
    {
        FatalErrorInFunction
            << "polyTopoChangeMap does not correspond to the old mesh."
            << " nCells:" << nCells()
            << " cellMap:" << map.cellMap().size()
            << " nOldCells:" << map.nOldCells()
            << " nFaces:" << nFaces()
            << " faceMap:" << map.faceMap().size()
            << " nOldFaces:" << map.nOldFaces()
            << exit(FatalError);
    }

    // Create a fv mapper
    const fvMeshMapper fvMap(*this, map);

    // Map all the volFields in the objectRegistry
    #define mapVolFieldType(Type, nullArg)                                     \
        MapGeometricFields<Type, fvMeshMapper, fvMesh>(fvMap);
    FOR_ALL_FIELD_TYPES(mapVolFieldType);

    // Map all the surfaceFields in the objectRegistry
    #define mapSurfaceFieldType(Type, nullArg)                                 \
        MapGeometricFields<Type, fvMeshMapper, surfaceMesh>(fvMap);
    FOR_ALL_FIELD_TYPES(mapSurfaceFieldType);

    // Map all the dimensionedFields in the objectRegistry
    #define mapVolInternalFieldType(Type, nullArg)                             \
        MapDimensionedFields<Type, fvMeshMapper, fvMesh>(fvMap);
    FOR_ALL_FIELD_TYPES(mapVolInternalFieldType);

    if (pointMesh::found(*this))
    {
        // Create the pointMesh mapper
        const pointMeshMapper mapper(pointMesh::New(*this), map);

        #define mapPointFieldType(Type, nullArg)                               \
            MapGeometricFields<Type, pointMeshMapper, pointMesh>(mapper);
        FOR_ALL_FIELD_TYPES(mapPointFieldType);
    }
}


void Foam::fvMesh::preChange()
{
    stitcher_->disconnect(true, true);
}


void Foam::fvMesh::setPoints(const pointField& p)
{
    polyMesh::setPoints(p);

    clearFvGeom();

    // Update other local data
    surfaceInterpolation::movePoints();

    meshObjects::movePoints<fvMesh>(*this);
    meshObjects::movePoints<lduMesh>(*this);

    const_cast<Time&>(time()).functionObjects().movePoints(*this);
}


Foam::tmp<Foam::scalarField> Foam::fvMesh::movePoints(const pointField& p)
{
    preChange();

    // Set the mesh to be moving. This remains true for the rest of the run.
    moving_ = true;

    // Create old-time volumes, if necessary, at the start of a new timestep
    if (curTimeIndex_ < time().timeIndex())
    {
        if (V00Ptr_ && notNull(V00Ptr_))
        {
            FatalErrorInFunction
                << "Old-old volumes should not be maintained across mesh "
                << "changes" << exit(FatalError);
        }

        // If old-old-volumes are necessary then copy them from the old-volumes
        if (Foam::isNull(V00Ptr_))
        {
            V00Ptr_ = new DimensionedField<scalar, fvMesh>
            (
                IOobject
                (
                    "Vc00",
                    time().name(),
                    *this,
                    IOobject::NO_READ,
                    IOobject::NO_WRITE,
                    true
                ),
                V0()
            );
        }

        // Copy old-volumes from the volumes
        if (!V0Ptr_ || Foam::isNull(V0Ptr_))
        {
            V0Ptr_ = new DimensionedField<scalar, fvMesh>
            (
                IOobject
                (
                    "Vc0",
                    time().name(),
                    *this,
                    IOobject::NO_READ,
                    IOobject::NO_WRITE,
                    true
                ),
                V()
            );
        }
        else
        {
            V0Ptr_->scalarField::operator=(V().primitiveField());
        }
    }

    // Create mesh motion flux, if necessary
    if (!phiPtr_)
    {
        phiPtr_ = new surfaceScalarField
        (
            IOobject
            (
                "meshPhi",
                this->time().name(),
                *this,
                IOobject::NO_READ,
                IOobject::NO_WRITE,
                true
            ),
            *this,
            dimensions::volumetricFlux,
            fvsPatchField<scalar>::calculatedType()
        );
    }
    else
    {
        phiPtr_->storeOldTimes();
    }

    surfaceScalarField& phi = *phiPtr_;

    // Move the polyMesh and set the mesh motion fluxes to the swept-volumes

    scalar rDeltaT = 1.0/time().deltaTValue();

    tmp<scalarField> tsweptVols = polyMesh::movePoints(p);

    scalarField& sweptVols = tsweptVols.ref();

    phi.primitiveFieldRef() =
        scalarField::subField(sweptVols, nInternalFaces());
    phi.primitiveFieldRef() *= rDeltaT;

    const fvPatchList& patches = boundary();

    surfaceScalarField::BoundaryField& phibf = phi.boundaryFieldRef();

    forAll(patches, patchi)
    {
        phibf[patchi] = patches[patchi].patchSlice(sweptVols);
        phibf[patchi] *= rDeltaT;
    }

    // Update or delete the local geometric properties as early as possible so
    // they can be used if necessary. These get recreated here instead of
    // demand driven since they might do parallel transfers which can conflict
    // with when they're actually being used.
    // Note that between above "polyMesh::movePoints(p)" and here nothing
    // should use the local geometric properties.
    updateGeomNotOldVol();

    // Update other local data
    surfaceInterpolation::movePoints();

    meshObjects::movePoints<fvMesh>(*this);
    meshObjects::movePoints<lduMesh>(*this);

    const_cast<Time&>(time()).functionObjects().movePoints(*this);

    return tsweptVols;
}


void Foam::fvMesh::topoChange(const polyTopoChangeMap& map)
{
    if (!conformal())
    {
        FatalErrorInFunction
            << "The mesh was not disconnected prior to topology change"
            << exit(FatalError);
    }

    // Update polyMesh. This needs to keep volume existent!
    polyMesh::topoChange(map);

    // Clear the sliced fields
    clearFvGeomNotOldVol();

    // Check that we're not trying to maintain old-time mesh geometry
    if (V0Ptr_ && Foam::notNull(V0Ptr_))
    {
        FatalErrorInFunction
            << "It is not possible to use mesh motion, topology change, and "
            << "second order time schemes simultaneously"
            << exit(FatalError);
    }

    // Map all fields
    mapFields(map);

    // Clear the current volume and other geometry factors
    surfaceInterpolation::clearOut();

    // Clear any non-updateable addressing
    clearAddressing(true);

    meshObjects::topoChange<fvMesh>(*this, map);
    meshObjects::topoChange<lduMesh>(*this, map);

    const_cast<Time&>(time()).functionObjects().topoChange(map);

    if (stitcher_.valid())
    {
        stitcher_->topoChange(map);
    }

    if (topoChanger_.valid())
    {
        topoChanger_->topoChange(map);
    }

    if (distributor_.valid())
    {
        distributor_->topoChange(map);
    }

    if (mover_.valid())
    {
        mover_->topoChange(map);
    }
}


void Foam::fvMesh::mapMesh(const polyMeshMap& map)
{
    if (!conformal())
    {
        FatalErrorInFunction
            << "The mesh was not disconnected prior to mesh-to-mesh mapping"
            << exit(FatalError);
    }

    // Distribute polyMesh data
    polyMesh::mapMesh(map);

    // Clear the sliced fields
    clearFvGeomNotOldVol();

    // Clear the current volume and other geometry factors
    surfaceInterpolation::clearOut();

    // Clear any non-updateable addressing
    clearAddressing(true);

    meshObjects::mapMesh<fvMesh>(*this, map);
    meshObjects::mapMesh<lduMesh>(*this, map);

    const_cast<Time&>(time()).functionObjects().mapMesh(map);

    stitcher_->mapMesh(map);
    topoChanger_->mapMesh(map);
    distributor_->mapMesh(map);
    mover_->mapMesh(map);
}


void Foam::fvMesh::distribute(const polyDistributionMap& map)
{
    if (!conformal())
    {
        FatalErrorInFunction
            << "The mesh was not disconnected prior to distribution"
            << exit(FatalError);
    }

    // Distribute polyMesh data
    polyMesh::distribute(map);

    // Clear the sliced fields
    clearFvGeomNotOldVol();

    // Clear the current volume and other geometry factors
    surfaceInterpolation::clearOut();

    // Clear any non-updateable addressing
    clearAddressing(true);

    meshObjects::distribute<fvMesh>(*this, map);
    meshObjects::distribute<lduMesh>(*this, map);

    const_cast<Time&>(time()).functionObjects().distribute(map);

    stitcher_->distribute(map);
    topoChanger_->distribute(map);
    distributor_->distribute(map);
    mover_->distribute(map);
}


void Foam::fvMesh::setPolyFacesBfInstance(const fileName& inst)
{
    if (!polyFacesBfPtr_)
    {
        return;
    }

    polyFacesBfIOPtr_->instance() = inst;
    polyFacesBfIOPtr_->writeOpt() = IOobject::AUTO_WRITE;
}


const Foam::fileName& Foam::fvMesh::polyFacesBfInstance() const
{
    if (!polyFacesBfPtr_)
    {
        return facesInstance();
    }

    return polyFacesBfIOPtr_->instance();
}


void Foam::fvMesh::conform(const surfaceScalarField& phi)
{
    // Clear the geometry fields
    clearFvGeomNotOldVol();

    // Clear the current volume and other geometry factors
    surfaceInterpolation::clearOut();

    // Clear any non-updateable addressing
    clearAddressing(true);

    // Modify the mesh fluxes, if necessary
    if (notNull(phi) && phiPtr_)
    {
        for (label i = 0; i <= phi.nOldTimes(); ++ i)
        {
            phiRef().oldTimeRef(i) == phi.oldTime(i);
        }
    }
}


void Foam::fvMesh::unconform
(
    const surfaceLabelField::Boundary& polyFacesBf,
    const surfaceVectorField& Sf,
    const surfaceVectorField& Cf,
    const surfaceScalarField& phi,
    const bool sync
)
{
    // Clear the geometry fields
    clearFvGeomNotOldVol();

    // Clear the current volume and other geometry factors
    surfaceInterpolation::clearOut();

    // Clear any non-updateable addressing
    clearAddressing(true);

    // Create non-sliced copies of geometry fields
    SfRef();
    magSfRef();
    CRef();
    CfRef();

    // Set the topology
    forAll(polyFacesBf, patchi)
    {
        polyFacesBfRef()[patchi].reset(polyFacesBf[patchi]);
    }

    // Set the face geometry
    SfRef() == Sf;
    magSfRef() == max(mag(Sf), dimensionedScalar(dimensions::area, rootVSmall));
    CRef().boundaryRef() == Cf.boundary();
    CfRef() == Cf;

    // Communicate processor-coupled cell geometry. Cell-centre processor patch
    // fields must contain the (transformed) cell-centre locations on the other
    // side of the coupling. This is so that non-conformal patches can
    // construct weights and deltas without reference to the poly mesh
    // geometry.
    //
    // Note that the initEvaluate/evaluate communication does a transformation,
    // but it is wrong in this instance. A vector field gets transformed as if
    // it were a displacement, but the cell-centres need a positional
    // transformation. That's why there's the un-transform and re-transform bit
    // below just after the evaluate call.
    //
    // This transform handling is a bit of a hack. It would be nicer to have a
    // field attribute which identifies a field as needing a positional
    // transformation, and for it to apply automatically within the coupled
    // patch field. However, at the moment, the cell centres field is the only
    // vol-field containing an absolute position, so the hack is functionally
    // sufficient for now.
    if (sync && time().completeCase())
    {
        volVectorField::BoundaryField& CBf = CRef().boundaryFieldRef();

        const label nReq = Pstream::nRequests();

        forAll(CBf, patchi)
        {
            if (isA<processorFvPatch>(CBf[patchi].patch()))
            {
                CBf[patchi].initEvaluate(Pstream::defaultCommsType);
            }
        }

        if
        (
            Pstream::parRun()
         && Pstream::defaultCommsType == Pstream::commsTypes::nonBlocking
        )
        {
            Pstream::waitRequests(nReq);
        }

        forAll(CBf, patchi)
        {
            if (isA<processorFvPatch>(CBf[patchi].patch()))
            {
                CBf[patchi].evaluate(Pstream::defaultCommsType);

                const transformer& t =
                    refCast<const processorFvPatch>(CBf[patchi].patch())
                   .transform();

                t.invTransform(CBf[patchi], CBf[patchi]);
                t.transformPosition(CBf[patchi], CBf[patchi]);
            }
        }
    }

    // Modify the mesh fluxes, if necessary
    if (notNull(phi) && phiPtr_)
    {
        for (label i = 0; i <= phi.nOldTimes(); ++ i)
        {
            phiRef().oldTimeRef(i) == phi.oldTime(i);
        }
    }
}


void Foam::fvMesh::addPatch
(
    const label insertPatchi,
    const polyPatch& patch
)
{
    // Remove my local data (see topoChange)
    // Clear mesh motion flux
    deleteDemandDrivenData(phiPtr_);

    // Clear the sliced fields
    clearFvGeomNotOldVol();

    // Clear the current volume and other geometry factors
    surfaceInterpolation::clearOut();

    // Clear any non-updateable addressing
    clearAddressing(true);

    const label boundarySize0 = boundary_.size();

    polyMesh::addPatch(insertPatchi, patch);

    boundary_.setSize(boundarySize0 + 1);
    boundary_.set
    (
        insertPatchi,
        fvPatch::New
        (
            poly().boundary()[insertPatchi],
            boundary_
        )
    );

    #define AddPatchFieldsType(Type, FieldType, DefaultPatchFieldType)         \
        AddPatchFields<FieldType<Type>>                                        \
        (                                                                      \
            const_cast<objectRegistry&>(db()),                                 \
            insertPatchi,                                                      \
            DefaultPatchFieldType                                              \
        );
    FOR_ALL_FIELD_TYPES
    (
        AddPatchFieldsType,
        VolField,
        extrapolatedCalculatedFvPatchField<scalar>::typeName
    );
    FOR_ALL_FIELD_TYPES
    (
        AddPatchFieldsType,
        SurfaceField,
        calculatedFvsPatchField<scalar>::typeName
    );
    #undef AddPatchFieldsType
}


void Foam::fvMesh::reorderPatches
(
    const labelUList& newToOld,
    const bool validBoundary
)
{
    polyMesh::reorderPatches(newToOld, validBoundary);

    boundary_.shuffle(newToOld, validBoundary);

    #define ReorderPatchFieldsType(Type, FieldType)                            \
        ReorderPatchFields<FieldType<Type>>                                    \
        (                                                                      \
            const_cast<objectRegistry&>(db()),                             \
            newToOld                                                           \
        );
    FOR_ALL_FIELD_TYPES(ReorderPatchFieldsType, VolField);
    FOR_ALL_FIELD_TYPES(ReorderPatchFieldsType, SurfaceField);
    #undef ReorderPatchFieldsType
}


bool Foam::fvMesh::writeObject
(
    IOstream::streamFormat fmt,
    IOstream::versionNumber ver,
    IOstream::compressionType cmp,
    const bool write
) const
{
    bool ok = true;

    if (!conformal() && polyFacesBfIOPtr_->writeOpt() == IOobject::AUTO_WRITE)
    {
        // Create a full surface field with the polyFacesBf boundary field to
        // write to disk. Make the internal field uniform to save disk space.

        surfaceLabelField polyFaces
        (
            *polyFacesBfIOPtr_,
            *this,
            dimless,
            labelField(nInternalFaces(), -1),
            *polyFacesBfPtr_
        );

        ok = ok & polyFaces.write(write);
    }

    // Write geometry out at a higher precision
    unsigned int precision0 =
        IOstream::defaultPrecision(IOstream::fullPrecision());

    // Write the mesh flux if old-old-time volumes exist
    if (phiPtr_ && V00Ptr_)
    {
        ok = ok && phiPtr_->write(write);
    }

    // Write old-time volumes if old-old-time volumes exist
    if (V0Ptr_ && V00Ptr_)
    {
        ok = ok && V0Ptr_->write(write);
    }

    // Restore the default precision
    IOstream::defaultPrecision(precision0);

    if (stitcher_.valid())
    {
        stitcher_->write(write);
    }

    if (topoChanger_.valid())
    {
        topoChanger_->write(write);
    }

    if (distributor_.valid())
    {
        distributor_->write(write);
    }

    if (mover_.valid())
    {
        mover_->write(write);
    }

    return ok && polyMesh::writeObject(fmt, ver, cmp, write);
}


bool Foam::fvMesh::writeMesh() const
{
    bool ok = true;

    if (!conformal() && polyFacesBfIOPtr_->writeOpt() == IOobject::AUTO_WRITE)
    {
        // Create a full surface field with the polyFacesBf boundary field to
        // write to disk. Make the internal field uniform to save disk space.

        surfaceLabelField polyFaces
        (
            *polyFacesBfIOPtr_,
            *this,
            dimless,
            labelField(nInternalFaces(), -1),
            *polyFacesBfPtr_
        );

        ok = ok & polyFaces.write();
    }

    return ok && polyMesh::writeMesh();
}


template<>
typename Foam::pTraits<Foam::sphericalTensor>::labelType
Foam::fvMesh::validComponents<Foam::sphericalTensor>() const
{
    return Foam::pTraits<Foam::sphericalTensor>::labelType(1);
}


const Foam::fvSchemes& Foam::fvMesh::schemes() const
{
    if (!fvSchemes_.valid())
    {
        fvSchemes_ = new fvSchemes(*this);
    }

    return fvSchemes_;
}


const Foam::fvSolution& Foam::fvMesh::solution() const
{
    if (!fvSolution_.valid())
    {
        fvSolution_ = new fvSolution(*this);
    }

    return fvSolution_;
}


// * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //

bool Foam::fvMesh::operator!=(const fvMesh& bm) const
{
    return &bm != this;
}


bool Foam::fvMesh::operator==(const fvMesh& bm) const
{
    return &bm == this;
}



// * * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * //

const Foam::fvMesh& Foam::region(const dictionary& dict)
{
    const IOobject& io = refCast<const IOobject>(dict);
    return refCast<const fvMesh>(io.db());
}


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