/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | foam-extend: Open Source CFD
   \\    /   O peration     | Version:     4.0
    \\  /    A nd           | Web:         http://www.foam-extend.org
     \\/     M anipulation  | For copyright notice see file Copyright
-------------------------------------------------------------------------------
License
    This file is part of foam-extend.

    foam-extend 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.

    foam-extend 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 foam-extend.  If not, see <http://www.gnu.org/licenses/>.

Description

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

#include "vtkFoam.H"
#include "fvMesh.H"
#include "cellModeller.H"

#include "vtkUnstructuredGrid.h"
#include "vtkCellArray.h"

#include "vtkFoamInsertNextPoint.H"

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

void Foam::vtkFoam::addInternalMesh
(
    const fvMesh& mesh,
    vtkUnstructuredGrid* vtkMesh
)
{
    SetName(vtkMesh, "Internal Mesh");

    // Number of additional points needed by the decomposition of polyhedra
    label nAddPoints = 0;

    // Number of additional cells generated by the decomposition of polyhedra
    label nAddCells = 0;

    const cellModel& tet = *(cellModeller::lookup("tet"));
    const cellModel& pyr = *(cellModeller::lookup("pyr"));
    const cellModel& prism = *(cellModeller::lookup("prism"));
    const cellModel& wedge = *(cellModeller::lookup("wedge"));
    const cellModel& tetWedge = *(cellModeller::lookup("tetWedge"));
    const cellModel& hex = *(cellModeller::lookup("hex"));

    // Scan for cells which need to be decomposed and count additional points
    // and cells
    if (debug)
    {
        Info<< "building cell-shapes" << endl;
    }
    const cellShapeList& cellShapes = mesh.cellShapes();

    if (debug)
    {
        Info<< "scanning" << endl;
    }

    forAll(cellShapes, cellI)
    {
        const cellModel& model = cellShapes[cellI].model();

        if
        (
            model != hex
         && model != wedge
         && model != prism
         && model != pyr
         && model != tet
         && model != tetWedge
        )
        {
            const cell& cFaces = mesh.cells()[cellI];

            forAll(cFaces, cFaceI)
            {
                const face& f = mesh.faces()[cFaces[cFaceI]];

                label nFacePoints = f.size();

                label nQuads = (nFacePoints - 2)/2;
                label nTris = (nFacePoints - 2)%2;
                nAddCells += nQuads + nTris;
            }

            nAddCells--;
            nAddPoints++;
        }
    }

    // Set size of additional point addressing array
    // (from added point to original cell)
    addPointCellLabels_.setSize(nAddPoints);

    // Set size of additional cells mapping array
    // (from added cell to original cell)
    superCells_.setSize(mesh.nCells() + nAddCells);

    if (debug)
    {
        Info<< "converting points" << endl;
    }

    // Convert Foam mesh vertices to VTK
    vtkPoints *vtkpoints = vtkPoints::New();
    vtkpoints->Allocate(mesh.nPoints() + nAddPoints);

    const Foam::pointField& points = mesh.points();

    forAll(points, i)
    {
        vtkFoamInsertNextPoint(vtkpoints, points[i]);
    }

    if (debug)
    {
        Info<< "converting cells" << endl;
    }

    vtkMesh->Allocate(mesh.nCells() + nAddCells);

    // Set counters for additional points and additional cells
    label api = 0, aci = 0;

    forAll(cellShapes, celli)
    {
        const cellShape& cellShape = cellShapes[celli];
        const cellModel& cellModel = cellShape.model();

        superCells_[aci++] = celli;

        if (cellModel == tet)
        {
            vtkMesh->InsertNextCell
            (
                VTK_TETRA,
                4,
                const_cast<int*>(cellShape.begin())
            );
        }
        else if (cellModel == pyr)
        {
            vtkMesh->InsertNextCell
            (
                VTK_PYRAMID,
                5,
                const_cast<int*>(cellShape.begin())
            );
        }
        else if (cellModel == prism)
        {
            vtkMesh->InsertNextCell
            (
                VTK_WEDGE,
                6,
                const_cast<int*>(cellShape.begin())
            );
        }
        else if (cellModel == tetWedge)
        {
            // Treat as squeezed prism

            int vtkVerts[6];
            vtkVerts[0] = cellShape[0];
            vtkVerts[1] = cellShape[2];
            vtkVerts[2] = cellShape[1];
            vtkVerts[3] = cellShape[3];
            vtkVerts[4] = cellShape[4];
            vtkVerts[5] = cellShape[4];

            vtkMesh->InsertNextCell(VTK_WEDGE, 6, vtkVerts);
        }
        else if (cellModel == wedge)
        {
            // Treat as squeezed hex

            int vtkVerts[8];
            vtkVerts[0] = cellShape[0];
            vtkVerts[1] = cellShape[1];
            vtkVerts[2] = cellShape[2];
            vtkVerts[3] = cellShape[2];
            vtkVerts[4] = cellShape[3];
            vtkVerts[5] = cellShape[4];
            vtkVerts[6] = cellShape[5];
            vtkVerts[7] = cellShape[6];

            vtkMesh->InsertNextCell(VTK_HEXAHEDRON, 8, vtkVerts);
        }
        else if (cellModel == hex)
        {
            vtkMesh->InsertNextCell
            (
                VTK_HEXAHEDRON,
                8,
                const_cast<int*>(cellShape.begin())
            );
        }
        else
        {
            // Polyhedral cell. Decompose into tets + prisms.

            // Mapping from additional point to cell
            addPointCellLabels_[api] = celli;

            // Insert the new vertex from the cell-centre
            label newVertexLabel = mesh.nPoints() + api;
            vtkFoamInsertNextPoint(vtkpoints, mesh.C()[celli]);

            // Whether to insert cell in place of original or not.
            bool substituteCell = true;

            const labelList& cFaces = mesh.cells()[celli];

            forAll(cFaces, cFaceI)
            {
                const face& f = mesh.faces()[cFaces[cFaceI]];

                label nFacePoints = f.size();

                label nQuads = (nFacePoints - 2)/2;
                label nTris = (nFacePoints - 2)%2;

                label qpi = 0;

                for (label quadi=0; quadi<nQuads; quadi++)
                {
                    label thisCellI = -1;

                    if (substituteCell)
                    {
                        thisCellI = celli;
                        substituteCell = false;
                    }
                    else
                    {
                        thisCellI = mesh.nCells() + aci;
                        superCells_[aci++] = celli;
                    }

                    int addVtkVerts[5];
                    addVtkVerts[0] = f[0];
                    addVtkVerts[1] = f[qpi + 1];
                    addVtkVerts[2] = f[qpi + 2];
                    addVtkVerts[3] = f[qpi + 3];
                    addVtkVerts[4] = newVertexLabel;
                    vtkMesh->InsertNextCell(VTK_PYRAMID, 5, addVtkVerts);

                    qpi += 2;
                }

                if (nTris)
                {
                    label thisCellI = -1;

                    if (substituteCell)
                    {
                        thisCellI = celli;
                        substituteCell = false;
                    }
                    else
                    {
                        thisCellI = mesh.nCells() + aci;
                        superCells_[aci++] = celli;
                    }

                    int addVtkVerts[4];
                    addVtkVerts[0] = f[0];
                    addVtkVerts[1] = f[qpi + 1];
                    addVtkVerts[2] = f[qpi + 2];
                    addVtkVerts[3] = newVertexLabel;
                    vtkMesh->InsertNextCell(VTK_TETRA, 4, addVtkVerts);
                }
            }

            api++;
        }
    }

    vtkMesh->SetPoints(vtkpoints);
    vtkpoints->Delete();
}


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