// Copyright (C) 2007-2013  CEA/DEN, EDF R&D
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
//
// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
//
// Author : Anthony Geay (CEA/DEN)
#ifndef __PolyhedronIntersectorP1P1_TXX__
#define __PolyhedronIntersectorP1P1_TXX__

#include "PolyhedronIntersectorP1P1.hxx"
#include "Intersector3DP1P1.txx"
#include "MeshUtils.hxx"

#include "SplitterTetra.txx"

namespace INTERP_KERNEL
{

  /**
   * Constructor creating object from target cell global number 
   * 
   * @param targetMesh  mesh containing the target elements
   * @param srcMesh     mesh containing the source elements
   * @param policy      splitting policy to be used
   */
  template<class MyMeshType, class MyMatrix>
  PolyhedronIntersectorP1P1<MyMeshType,MyMatrix>::PolyhedronIntersectorP1P1(const MyMeshType& targetMesh, const MyMeshType& srcMesh, SplittingPolicy policy):Intersector3DP1P1<MyMeshType,MyMatrix>(targetMesh,srcMesh)
  {
    // SPEC:
    // "Limitation. Concerning P1P1 3D improvement only tetrahedron will be supported.
    // If another type than tetrahedron is detected an INTERP_KERNEL::Exception should be thrown"

    // Check types of elements here rather than in intersectCells() since a wrong type can be
    // found late after a long time of calculation.

    const unsigned long numSrcElems = srcMesh.getNumberOfElements();
    for(unsigned long i = 0 ; i < numSrcElems ; ++i)
      if ( srcMesh.getTypeOfElement( OTT<ConnType,numPol>::indFC( i )) != NORM_TETRA4 )
        throw INTERP_KERNEL::Exception("P1P1 3D algorithm works only with tetrahedral meshes");

    const unsigned long numTgtElems = targetMesh.getNumberOfElements();
    for(unsigned long i = 0 ; i < numTgtElems ; ++i)
      if ( targetMesh.getTypeOfElement( OTT<ConnType,numPol>::indFC( i )) != NORM_TETRA4 )
        throw INTERP_KERNEL::Exception("P1P1 3D algorithm works only with tetrahedral meshes");
  }

  /**
   * Destructor.
   */
  template<class MyMeshType, class MyMatrix>
  PolyhedronIntersectorP1P1<MyMeshType,MyMatrix>::~PolyhedronIntersectorP1P1()
  {
  }

  /**
   * Calculates the volume of intersection of an element in the source mesh and the target element
   * represented by the object.
   * 
   * @param targetCell in C mode.
   * @param srcCells in C mode.
   */
  template<class MyMeshType, class MyMatrix>
  void PolyhedronIntersectorP1P1<MyMeshType,MyMatrix>::intersectCells(ConnType targetCell, const std::vector<ConnType>& srcCells, MyMatrix& res)
  {
#ifdef _DEBUG_
    UnitTetraIntersectionBary b; b.init();
#endif
    // split the targetCell into dual cells
    std::pair< int, std::vector<double> > subTetraNodes[24]; // a node of sub tetra and its coordinates
    const double* nodes[4]; int conn[4];
    for(int node = 0; node < 4 ; ++node)
      nodes[node]=getCoordsOfNode2(node, OTT<ConnType,numPol>::indFC(targetCell),
                                   Intersector3D<MyMeshType,MyMatrix>::_target_mesh,conn[node]);
    SplitterTetra<MyMeshType> tgtTetra(Intersector3D<MyMeshType,MyMatrix>::_src_mesh, nodes, conn);
    for (int i=0; i<24; i++)
      {
        subTetraNodes[i].second.resize(12);
        tgtTetra.splitMySelfForDual(&subTetraNodes[i].second[0],i,subTetraNodes[i].first);
      }
    // intersect each source tetrahedron with each of target dual cells
    SplitterTetra<MyMeshType>* subTetrasS[24];
    for(typename std::vector<ConnType>::const_iterator iterCellS=srcCells.begin();iterCellS!=srcCells.end();iterCellS++)
      {
        // split a source cell into dual cells
        for(int node = 0; node < 4 ; ++node)
          nodes[node]=getCoordsOfNode2(node, OTT<ConnType,numPol>::indFC(*iterCellS),
                                       Intersector3D<MyMeshType,MyMatrix>::_src_mesh,conn[node]);

        SplitterTetra<MyMeshType> srcTetra(Intersector3D<MyMeshType,MyMatrix>::_target_mesh, nodes, conn);
        srcTetra.splitIntoDualCells(subTetrasS);

        // intersect each target subTetra with each source one
        for(int i=0;i<24;i++)
          {
            SplitterTetra<MyMeshType> *tmp=subTetrasS[i];
            ConnType sourceNode=OTT<ConnType,numPol>::indFC(tmp->getId(0));
            for(int j=0;j<24;j++)
              {
                const double* tetraNodes12 = &subTetraNodes[j].second[0];
                const double* tetraNodesT[4]={ tetraNodes12, tetraNodes12+3, tetraNodes12+6, tetraNodes12+9 };
                double volume = tmp->intersectTetra( tetraNodesT );
                if(volume!=0.)
                  {
                    ConnType tgtNode=subTetraNodes[j].first;
                    typename MyMatrix::value_type& resRow = res[tgtNode];
                    typename MyMatrix::value_type::const_iterator iterRes=resRow.find( sourceNode );
                    if(iterRes!=resRow.end())
                      {
                        volume += (*iterRes).second;
                        resRow.erase(sourceNode);
                      }
                    resRow.insert(std::make_pair(sourceNode,volume));
                  }
              }
            delete tmp;
          }
      }
  }
}

#endif