//  SMESH SMESH : implementaion of SMESH idl descriptions
//
//  Copyright (C) 2003  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
//  CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS 
// 
//  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.opencascade.org/SALOME/ or email : webmaster.salome@opencascade.org 
//
//
//
//  File   : SMESH_Algo.cxx
//  Author : Paul RASCLE, EDF
//  Module : SMESH
//  $Header$

using namespace std;
#include "SMESH_Algo.hxx"
#include "SMESH_Gen.hxx"
#include "SMESH_Mesh.hxx"
#include "SMESH_HypoFilter.hxx"
#include "SMDS_FacePosition.hxx"
#include "SMDS_MeshElement.hxx"
#include "SMDS_MeshNode.hxx"
#include "SMESHDS_Mesh.hxx"
#include "SMESHDS_SubMesh.hxx"

#include <BRep_Tool.hxx>
#include <GCPnts_AbscissaPoint.hxx>
#include <GeomAdaptor_Curve.hxx>
#include <Geom_Surface.hxx>
#include <TopLoc_Location.hxx>
#include <TopTools_ListIteratorOfListOfShape.hxx>
#include <TopTools_ListOfShape.hxx>
#include <TopoDS.hxx>
#include <TopoDS_Face.hxx>
#include <gp_Pnt.hxx>
#include <gp_Pnt2d.hxx>
#include <gp_Vec.hxx>

#include "utilities.h"

#include <algorithm>

//=============================================================================
/*!
 *  
 */
//=============================================================================

SMESH_Algo::SMESH_Algo(int hypId, int studyId,
	SMESH_Gen * gen):SMESH_Hypothesis(hypId, studyId, gen)
{
//   _compatibleHypothesis.push_back("hypothese_bidon");
	_type = ALGO;
	gen->_mapAlgo[hypId] = this;

        _onlyUnaryInput = _requireDescretBoundary = true;
}

//=============================================================================
/*!
 *  
 */
//=============================================================================

SMESH_Algo::~SMESH_Algo()
{
}

//=============================================================================
/*!
 *  
 */
//=============================================================================

const vector < string > &SMESH_Algo::GetCompatibleHypothesis()
{
	return _compatibleHypothesis;
}

//=============================================================================
/*!
 *  List the hypothesis used by the algorithm associated to the shape.
 *  Hypothesis associated to father shape -are- taken into account (see
 *  GetAppliedHypothesis). Relevant hypothesis have a name (type) listed in
 *  the algorithm. This method could be surcharged by specific algorithms, in 
 *  case of several hypothesis simultaneously applicable.
 */
//=============================================================================

const list <const SMESHDS_Hypothesis *> & SMESH_Algo::GetUsedHypothesis(
	SMESH_Mesh & aMesh, const TopoDS_Shape & aShape)
{
  _usedHypList.clear();
  if ( !_compatibleHypothesis.empty() )
  {
    SMESH_HypoFilter filter( SMESH_HypoFilter::HasName( _compatibleHypothesis[0] ));
    for ( int i = 1; i < _compatibleHypothesis.size(); ++i )
      filter.Or( filter.HasName( _compatibleHypothesis[ i ] ));

    aMesh.GetHypotheses( aShape, filter, _usedHypList, true );
    if ( _usedHypList.size() > 1 )
      _usedHypList.clear();	//only one compatible hypothesis allowed
  }
  return _usedHypList;
}

//=============================================================================
/*!
 *  List the relevant hypothesis associated to the shape. Relevant hypothesis
 *  have a name (type) listed in the algorithm. Hypothesis associated to
 *  father shape -are not- taken into account (see GetUsedHypothesis)
 */
//=============================================================================

const list<const SMESHDS_Hypothesis *> & SMESH_Algo::GetAppliedHypothesis(
	SMESH_Mesh & aMesh, const TopoDS_Shape & aShape)
{
  _appliedHypList.clear();
  if ( !_compatibleHypothesis.empty() )
  {
    SMESH_HypoFilter filter( SMESH_HypoFilter::HasName( _compatibleHypothesis[0] ));
    for ( int i = 1; i < _compatibleHypothesis.size(); ++i )
      filter.Or( filter.HasName( _compatibleHypothesis[ i ] ));
    
    aMesh.GetHypotheses( aShape, filter, _appliedHypList, false );
  }
  return _appliedHypList;
}

//=============================================================================
/*!
 *  Compute length of an edge
 */
//=============================================================================

double SMESH_Algo::EdgeLength(const TopoDS_Edge & E)
{
	double UMin = 0, UMax = 0;
	TopLoc_Location L;
	if (BRep_Tool::Degenerated(E))
		return 0;
	Handle(Geom_Curve) C = BRep_Tool::Curve(E, L, UMin, UMax);
	GeomAdaptor_Curve AdaptCurve(C);
	GCPnts_AbscissaPoint gabs;
	double length = gabs.Length(AdaptCurve, UMin, UMax);
	return length;
}

//================================================================================
/*!
 * \brief Find out elements orientation on a geometrical face
  * \param theFace - The face correctly oriented in the shape being meshed
  * \param theMeshDS - The mesh data structure
  * \retval bool - true if the face normal and the normal of first element
  *                in the correspoding submesh point in different directions
 */
//================================================================================

bool SMESH_Algo::IsReversedSubMesh (const TopoDS_Face&  theFace,
                                    SMESHDS_Mesh*       theMeshDS)
{
  if ( theFace.IsNull() || !theMeshDS )
    return false;

  // find out orientation of a meshed face
  int faceID = theMeshDS->ShapeToIndex( theFace );
  TopoDS_Shape aMeshedFace = theMeshDS->IndexToShape( faceID );
  bool isReversed = ( theFace.Orientation() != aMeshedFace.Orientation() );

  const SMESHDS_SubMesh * aSubMeshDSFace = theMeshDS->MeshElements( faceID );
  if ( !aSubMeshDSFace )
    return isReversed;

  // find element with node located on face and get its normal
  const SMDS_FacePosition* facePos = 0;
  int vertexID = 0;
  gp_Pnt nPnt[3];
  gp_Vec Ne;
  bool normalOK = false;
  SMDS_ElemIteratorPtr iteratorElem = aSubMeshDSFace->GetElements();
  while ( iteratorElem->more() ) // loop on elements on theFace
  {
    const SMDS_MeshElement* elem = iteratorElem->next();
    if ( elem && elem->NbNodes() > 2 ) {
      SMDS_ElemIteratorPtr nodesIt = elem->nodesIterator();
      const SMDS_FacePosition* fPos = 0;
      int i = 0, vID = 0;
      while ( nodesIt->more() ) { // loop on nodes
        const SMDS_MeshNode* node
          = static_cast<const SMDS_MeshNode *>(nodesIt->next());
        if ( i == 3 ) i = 2;
        nPnt[ i++ ].SetCoord( node->X(), node->Y(), node->Z() );
        // check position
        const SMDS_PositionPtr& pos = node->GetPosition();
        if ( !pos ) continue;
        if ( pos->GetTypeOfPosition() == SMDS_TOP_FACE ) {
          fPos = dynamic_cast< const SMDS_FacePosition* >( pos.get() );
        }
        else if ( pos->GetTypeOfPosition() == SMDS_TOP_VERTEX ) {
          vID = pos->GetShapeId();
        }
      }
      if ( fPos || ( !normalOK && vID )) {
        // compute normal
        gp_Vec v01( nPnt[0], nPnt[1] ), v02( nPnt[0], nPnt[2] );
        if ( v01.SquareMagnitude() > RealSmall() &&
             v02.SquareMagnitude() > RealSmall() )
        {
          Ne = v01 ^ v02;
          normalOK = ( Ne.SquareMagnitude() > RealSmall() );
        }
        // we need position on theFace or at least on vertex
        if ( normalOK ) {
          vertexID = vID;
          if ((facePos = fPos))
            break;
        }
      }
    }
  }
  if ( !normalOK )
    return isReversed;

  // node position on face
  double u,v;
  if ( facePos ) {
    u = facePos->GetUParameter();
    v = facePos->GetVParameter();
  }
  else if ( vertexID ) {
    TopoDS_Shape V = theMeshDS->IndexToShape( vertexID );
    if ( V.IsNull() || V.ShapeType() != TopAbs_VERTEX )
      return isReversed;
    gp_Pnt2d uv = BRep_Tool::Parameters( TopoDS::Vertex( V ), theFace );
    u = uv.X();
    v = uv.Y();
  }
  else
  {
    return isReversed;
  }

  // face normal at node position
  TopLoc_Location loc;
  Handle(Geom_Surface) surf = BRep_Tool::Surface( theFace, loc );
  if ( surf.IsNull() || surf->Continuity() < GeomAbs_C1 ) return isReversed;
  gp_Vec d1u, d1v;
  surf->D1( u, v, nPnt[0], d1u, d1v );
  gp_Vec Nf = (d1u ^ d1v).Transformed( loc );

  if ( theFace.Orientation() == TopAbs_REVERSED )
    Nf.Reverse();

  return Ne * Nf < 0.;
}