/*---------------------------------------------------------------------------*\
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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::InteractionLists

Description

    Builds direct interaction list, specifying which local (real)
    cells are potentially in range of each other.

    Builds referred interaction list, specifying which cells are
    required to provide interactions across coupled patches (cyclic or
    processor).  Generates referred cells, and refers particles to the
    correct processor, applying the appropriate transform.

    Simultaneous communication and computation is possible using:

    \verbatim
    PstreamBuffers pBufs(Pstream::commsTypes::nonBlocking);
    label startOfRequests = Pstream::nRequests();
    il_.sendReferredData(cellOccupancy_, pBufs);
    // Do other things
    il_.receiveReferredData(pBufs, startOfRequests);
    \endverbatim

    Requiring data:

    \verbatim
    List<DynamicList<typename CloudType::parcelType*>> cellOccupancy_;
    \endverbatim

SourceFiles
    InteractionListsI.H
    InteractionLists.C
    InteractionListsIO.C

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

#ifndef InteractionLists_H
#define InteractionLists_H

#include "polyMesh.H"
#include "referredWallFace.H"
//#include "distributionMap.H"

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

namespace Foam
{

class globalIndexAndTransform;
class distributionMap;

/*---------------------------------------------------------------------------*\
                      Class InteractionLists Declaration
\*---------------------------------------------------------------------------*/

template<class ParticleType>
class InteractionLists
{
    // Private Data

        //- Reference to mesh
        const polyMesh& mesh_;

        //- Dummy cloud to give to particles
        lagrangian::Cloud<ParticleType> cloud_;

        //- Switch controlling whether or not the cloud gets populated
        //  with the referred particles, hence gets written out
        const Switch writeCloud_;

        //- distributionMap to exchange referred particles into referred cells
        autoPtr<distributionMap> cellMapPtr_;

        //- distributionMap to exchange wall face data
        autoPtr<distributionMap> wallFaceMapPtr_;

        //- Maximum distance over which interactions will be detected
        scalar maxDistance_;

        //- Direct interaction list
        labelListList dil_;

        //- Wall faces on this processor that are in interaction range
        //  of each each cell (direct wall face interaction list)
        labelListList dwfil_;

        //- Referred interaction list - which real cells are to be
        //  supplied with particle interactions from the referred
        //  particle container with the same index.
        labelListList ril_;

        //- Inverse addressing for referred cells, specifies which
        //  referred cells (indices of entries in the ril_ and
        //  referredParticles_ lists) interact with the real cell
        //  indexed in this container.
        labelListList rilInverse_;

        //- Which real cells on this on this processor are in
        //  interaction range of each referred wall face (referred
        //  wall face interaction list)
        labelListList rwfil_;

        //- Inverse addressing for referred wall faces, specifies
        //  which referred wall faces interact with the real cells
        //  indexed in this container.
        labelListList rwfilInverse_;

        //- Which cells are to be sent via the cellMap, and an index
        //  specifying how they should be transformed.
        List<labelPair> cellIndexAndTransformToDistribute_;

        //- Which wallFaces are to be sent via the wallFaceMap, and an index
        //  specifying how they should be transformed.
        List<labelPair> wallFaceIndexAndTransformToDistribute_;

        //- Referred wall faces
        List<referredWallFace> referredWallFaces_;

        //- Velocity field name, default to "U"
        const word UName_;

        //- Referred wall face velocity field values;
        List<vector> referredWallData_;

        //- Referred particle container
        List<IDLList<ParticleType>> referredParticles_;


    // Private Member Functions

        //- Construct all interaction lists
        void buildInteractionLists();

        //- Find the other processors which have interaction range
        //  extended bound boxes in range
        void findExtendedProcBbsInRange
        (
            const treeBoundBox& procBb,
            const List<treeBoundBox>& allExtendedProcBbs,
            const globalIndexAndTransform& globalTransforms,
            List<treeBoundBox>& extendedProcBbsInRange,
            List<label>& extendedProcBbsTransformIndex,
            List<label>& extendedProcBbsOrigProc
        );

        //- Build the distributionMap from information about which entry
        //  is to be sent to which processor
        void buildMap
        (
            autoPtr<distributionMap>& mapPtr,
            const List<label>& toProc
        );

        //- Fill the referredParticles container with particles that
        //  will be referred
        void prepareParticlesToRefer
        (
            const List<DynamicList<ParticleType*>>& cellOccupancy
        );

        //- Prepare particle to be referred
        void prepareParticleToBeReferred
        (
            ParticleType* particle,
            labelPair iat
        );

        //- Fill the referredParticles so that it will be written out
        void fillReferredParticleCloud();

        //- Populate the referredWallData container with data that
        //  will be referred.
        void prepareWallDataToRefer();

        //- Write the referred wall faces out for debug
        void writeReferredWallFaces() const;


public:

    // Constructors

        //- Construct null from mesh
        InteractionLists(const polyMesh& mesh);

        //- Construct and call function to create all information from
        //  the mesh
        InteractionLists
        (
            const polyMesh& mesh,
            scalar maxDistance,
            Switch writeCloud = false,
            const word& UName = "U"
        );

        //- Disallow default bitwise copy construction
        InteractionLists(const InteractionLists&) = delete;


    // Destructor

        ~InteractionLists();


    // Member Functions

        //- Prepare and send referred particles and wall data,
        //  nonBlocking communication
        void sendReferredData
        (
            const List<DynamicList<ParticleType*>>& cellOccupancy,
            PstreamBuffers& pBufs
        );

        //- Receive referred data
        void receiveReferredData
        (
            PstreamBuffers& pBufs,
            const label startReq = 0
        );


        // Access

            //- Return access to the mesh
            inline const polyMesh& mesh() const;

            //- Return access to the cellMap
            inline const distributionMap& cellMap() const;

            //- Return access to the wallFaceMap
            inline const distributionMap& wallFaceMap() const;

            //- Return access to the direct interaction list
            inline const labelListList& dil() const;

            //- Return access to the direct wall face interaction list
            inline const labelListList& dwfil() const;

            //- Return access to the referred interaction list
            inline const labelListList& ril() const;

            //- Return access to the inverse referred interaction list
            inline const labelListList& rilInverse() const;

            //- Return access to the referred wall face interaction list
            inline const labelListList& rwfil() const;

            //- Return access to the inverse referred wall face
            //  interaction list
            inline const labelListList& rwfilInverse() const;

            //- Return access to the cellIndexAndTransformToDistribute list
            inline const List<labelPair>&
            cellIndexAndTransformToDistribute() const;

            //- Return access to the wallFaceIndexAndTransformToDistribute list
            inline const List<labelPair>&
            wallFaceIndexAndTransformToDistribute() const;

            //- Return access to the referred wall faces
            inline const List<referredWallFace>& referredWallFaces() const;

            //- Return the name of the velocity field
            inline const word& UName() const;

            //- Return access to the referred wall data
            inline const List<vector>& referredWallData() const;

            //- Return access to the referred particle container
            inline const List<IDLList<ParticleType>>&
            referredParticles() const;

            //- Return non-const access to the referred particle container
            inline List<IDLList<ParticleType>>& referredParticles();


    // Member Operators

        //- Disallow default bitwise assignment
        void operator=(const InteractionLists&) = delete;
};


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

} // End namespace Foam

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

#include "InteractionListsI.H"

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

#ifdef NoRepository
    #include "InteractionLists.C"
#endif

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

#endif

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