using namespace std;
//=============================================================================
// File      : SMESH_Quadrangle_2D.cxx
// Created   : sam mai 18 08:11:32 CEST 2002
// Author    : Paul RASCLE, EDF
// Project   : SALOME
// Copyright : EDF 2002
// $Header$
//=============================================================================
using namespace std;

#include "SMESH_Quadrangle_2D.hxx"
#include "SMESH_Gen.hxx"
#include "SMESH_Mesh.hxx"

#include "SMDS_MeshElement.hxx"
#include "SMDS_MeshNode.hxx"
#include "SMDS_EdgePosition.hxx"
#include "SMDS_FacePosition.hxx"

#include <BRep_Tool.hxx>
#include <BRepTools.hxx>
#include <BRepTools_WireExplorer.hxx>
#include <Geom_Surface.hxx>
#include <Geom_Curve.hxx>
#include <Geom2d_Curve.hxx>
#include <Handle_Geom2d_Curve.hxx>
#include <Handle_Geom_Curve.hxx>
#include <gp_Pnt2d.hxx>
#include <TColStd_ListIteratorOfListOfInteger.hxx>

#include "utilities.h"

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

SMESH_Quadrangle_2D::SMESH_Quadrangle_2D(int hypId, 
					 int studyId, 
					 SMESH_Gen* gen)
  : SMESH_2D_Algo(hypId, studyId, gen)
{
  MESSAGE("SMESH_Quadrangle_2D::SMESH_Quadrangle_2D");
  _name = "Quadrangle_2D";
  //  _shapeType = TopAbs_FACE;
  _shapeType = (1<<TopAbs_FACE);
}

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

SMESH_Quadrangle_2D::~SMESH_Quadrangle_2D()
{
  MESSAGE("SMESH_Quadrangle_2D::~SMESH_Quadrangle_2D");
}

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

bool SMESH_Quadrangle_2D::CheckHypothesis(SMESH_Mesh& aMesh,
					  const TopoDS_Shape& aShape)
{
  //MESSAGE("SMESH_Quadrangle_2D::CheckHypothesis");

  bool isOk = true;

  // nothing to check

  return isOk;
}


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

bool SMESH_Quadrangle_2D::Compute(SMESH_Mesh& aMesh,
				  const TopoDS_Shape& aShape)
  throw (SALOME_Exception)
{
  //MESSAGE("SMESH_Quadrangle_2D::Compute");
  const Handle(SMESHDS_Mesh)& meshDS = aMesh.GetMeshDS();
  SMESH_subMesh* theSubMesh = aMesh.GetSubMesh(aShape);

  FaceQuadStruct* quad = CheckAnd2Dcompute(aMesh, aShape);
  if (!quad) return false;

  // --- compute 3D values on points, store points & quadrangles

  int nbdown = quad->nbPts[0];
  int nbright = quad->nbPts[1];
  int nbVertices = nbdown*nbright;
  int nbQuad = (nbdown-1)*(nbright-1);
  //SCRUTE(nbVertices);
  //SCRUTE(nbQuad);

  //   const TopoDS_Face& FF = TopoDS::Face(aShape);
  //   bool faceIsForward = (FF.Orientation() == TopAbs_FORWARD);
  //   TopoDS_Face F = TopoDS::Face(FF.Oriented(TopAbs_FORWARD));
  const TopoDS_Face& F = TopoDS::Face(aShape);
  bool faceIsForward = (F.Orientation() == TopAbs_FORWARD);
  Handle(Geom_Surface) S = BRep_Tool::Surface(F);

  for (int i=1; i<nbdown-1; i++)
    for (int j=1; j<nbright-1; j++)    // internal points
      {
	int ij = j*nbdown +i;
	double u = quad->uv_grid[ij].u;
	double v = quad->uv_grid[ij].v;
	gp_Pnt P = S->Value(u,v);
	int nodeId = meshDS->AddNode(P.X(), P.Y(), P.Z());
	//MESSAGE("point "<< nodeId<<" "<<" "<<P.X()<<" "<<P.Y()<<" "<<P.Z());
	Handle (SMDS_MeshElement) elt = meshDS->FindNode(nodeId);
	Handle (SMDS_MeshNode) node = meshDS->GetNode(1, elt);
	meshDS->SetNodeOnFace(node, F);
	quad->uv_grid[ij].nodeId = nodeId; 
// 	Handle (SMDS_FacePosition) fpos
// 	  = new SMDS_FacePosition(theSubMesh->GetId(),i,j); // easier than u,v
// 	node->SetPosition(fpos);
	Handle (SMDS_FacePosition) fpos
	  = Handle (SMDS_FacePosition)::DownCast(node->GetPosition());
	fpos->SetUParameter(i);
	fpos->SetVParameter(j);
      }

  //   bool isQuadForward = ( faceIsForward == quad->isEdgeForward[0]);
  for (int i=0; i<nbdown-1; i++)
    for (int j=0; j<nbright-1; j++)    // faces
      {
	int a = quad->uv_grid[   j *nbdown +i  ].nodeId;
	int b = quad->uv_grid[   j *nbdown +i+1].nodeId;
	int c = quad->uv_grid[(j+1)*nbdown +i+1].nodeId;
	int d = quad->uv_grid[(j+1)*nbdown +i  ].nodeId;
	int faceId;
	// 	if (isQuadForward) faceId = meshDS->AddFace(a,b,c,d);
	// 	else faceId = meshDS->AddFace(a,d,c,b);
	faceId = meshDS->AddFace(a,b,c,d);
	Handle (SMDS_MeshElement) elt = meshDS->FindElement(faceId);
	meshDS->SetMeshElementOnShape(elt, F);
      }

  QuadDelete(quad);
  bool isOk = true;
  return isOk;
}

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

FaceQuadStruct*
SMESH_Quadrangle_2D::CheckAnd2Dcompute(SMESH_Mesh& aMesh,
				       const TopoDS_Shape& aShape)
  throw (SALOME_Exception)
{
  //MESSAGE("SMESH_Quadrangle_2D::ComputeWithoutStore");

  SMESH_subMesh* theSubMesh = aMesh.GetSubMesh(aShape);

  //   const TopoDS_Face& FF = TopoDS::Face(aShape);
  //   bool faceIsForward = (FF.Orientation() == TopAbs_FORWARD);
  //   TopoDS_Face F = TopoDS::Face(FF.Oriented(TopAbs_FORWARD));
  const TopoDS_Face& F = TopoDS::Face(aShape);
  bool faceIsForward = (F.Orientation() == TopAbs_FORWARD);

  // verify 1 wire only, with 4 edges, same number of points on opposite edges

  if (NumberOfWires (F) != 1)
    {
      MESSAGE("only 1 wire by face (quadrangles)");
      return 0;
      //throw SALOME_Exception(LOCALIZED("only 1 wire by face (quadrangles)"));
    }
  //   const TopoDS_Wire WW = BRepTools::OuterWire(F);
  //   TopoDS_Wire W = TopoDS::Wire(WW.Oriented(TopAbs_FORWARD));
  const TopoDS_Wire& W = BRepTools::OuterWire(F);
  BRepTools_WireExplorer wexp(W,F);    

  FaceQuadStruct* quad = new FaceQuadStruct;
  for (int i=0; i<4; i++) quad->uv_edges[i] = 0;
  quad->uv_grid = 0;

  int nbEdges = 0;
  for (wexp.Init(W,F);wexp.More(); wexp.Next())
    {
      //       const TopoDS_Edge& EE = wexp.Current();
      //       TopoDS_Edge E = TopoDS::Edge(EE.Oriented(TopAbs_FORWARD));
      const TopoDS_Edge& E = wexp.Current();
      int nb = aMesh.GetSubMesh(E)->GetSubMeshDS()->NbNodes();
      if (nbEdges < 4)
	{	  
	  quad->edge[nbEdges] = E;
	  quad->nbPts[nbEdges] = nb +2; // internal points + 2 extrema
	}
      nbEdges++;
    }

  if (nbEdges != 4)
    {
      MESSAGE("face must have 4 edges /quadrangles");
      QuadDelete(quad);
      return 0;
      //throw SALOME_Exception(LOCALIZED("face must have 4 edges /quadrangles"));
    }

  if (quad->nbPts[0] != quad->nbPts[2])
    {
      MESSAGE("different point number-opposed edge");
      QuadDelete(quad);
      return 0;
      //throw SALOME_Exception(LOCALIZED("different point number-opposed edge"));
    }

  if (quad->nbPts[1] != quad->nbPts[3])
    {
      MESSAGE("different point number-opposed edge");
      QuadDelete(quad);
      return 0;
      //throw SALOME_Exception(LOCALIZED("different point number-opposed edge"));
    }

  // set normalized grid on unit square in parametric domain

  SetNormalizedGrid(aMesh, F, quad);
  
  return quad;
}


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

  void SMESH_Quadrangle_2D::QuadDelete(FaceQuadStruct* quad)
{
  //MESSAGE("SMESH_Quadrangle_2D::QuadDelete");
  if (quad)
    {
      for (int i=0; i<4; i++)
	{
	  if (quad->uv_edges[i]) delete [] quad->uv_edges[i];
	  quad->edge[i].Nullify();
	}
      if (quad->uv_grid) delete [] quad->uv_grid;
      delete quad;
   }
}

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

void SMESH_Quadrangle_2D::SetNormalizedGrid(SMESH_Mesh& aMesh,
					    const TopoDS_Shape& aShape,
					    FaceQuadStruct* quad)
  throw (SALOME_Exception)
{
  // Algorithme décrit dans "Génération automatique de maillages"
  // P.L. GEORGE, MASSON, § 6.4.1 p. 84-85
  // traitement dans le domaine paramétrique 2d u,v
  // transport - projection sur le carré unité

  const TopoDS_Face& F = TopoDS::Face(aShape);

  // 1 --- find orientation of the 4 edges, by test on extrema

  //      max             min                    0     x1     1
  //     |<----north-2-------^                a3 -------------> a2
  //     |                   |                   ^1          1^
  //    west-3            east-1 =right          |            |
  //     |                   |         ==>       |            |
  //  y0 |                   | y1                |            |
  //     |                   |                   |0          0|
  //     v----south-0-------->                a0 -------------> a1
  //      min             max                    0     x0     1
  //             =down
  //

  Handle (Geom2d_Curve) c2d[4];
  gp_Pnt2d pf[4];
  gp_Pnt2d pl[4];
  for (int i=0; i<4; i++)
    {
      c2d[i] = BRep_Tool::CurveOnSurface(quad->edge[i],
					 F,
					 quad->first[i],
					 quad->last[i]);
      pf[i] = c2d[i]->Value(quad->first[i]);
      pl[i] = c2d[i]->Value(quad->last[i]);
      quad->isEdgeForward[i] = false;
    }

  double eps2d = 1.e-3; // *** utiliser plutot TopExp::CommonVertex, puis
                        // distances si piece fausse
  int i=0;
  if ((pf[1].Distance(pl[0]) < eps2d) || (pl[1].Distance(pl[0]) < eps2d))
    {
      quad->isEdgeForward[0] = true;
    }
  else
    {
      double tmp =quad->first[0];
      quad->first[0] = quad->last[0];
      quad->last[0] = tmp;
      pf[0] = c2d[0]->Value(quad->first[0]);
      pl[0] = c2d[0]->Value(quad->last[0]);
    }
  for (int i=1; i<4; i++)
    {
      quad->isEdgeForward[i] = (pf[i].Distance(pl[i-1]) < eps2d);
      if (! quad->isEdgeForward[i])
	{
	  double tmp =quad->first[i];
	  quad->first[i] = quad->last[i];
	  quad->last[i] = tmp;
	  pf[i] = c2d[i]->Value(quad->first[i]);
	  pl[i] = c2d[i]->Value(quad->last[i]);
	  //SCRUTE(pf[i].Distance(pl[i-1]));
	  ASSERT(pf[i].Distance(pl[i-1]) < eps2d);
	}
    }
  //SCRUTE(pf[0].Distance(pl[3]));
  ASSERT(pf[0].Distance(pl[3]) < eps2d);

//   for (int i=0; i<4; i++)
//     {
//       SCRUTE(quad->isEdgeForward[i]);
//       MESSAGE(" -first "<<i<<" "<<pf[i].X()<<" "<<pf[i].Y());
//       MESSAGE(" -last  "<<i<<" "<<pl[i].X()<<" "<<pl[i].Y());
//     }

  // 2 --- load 2d edge points (u,v) with orientation and value on unit square

  for (int i=0; i<2; i++)
    {
      quad->uv_edges[i] = LoadEdgePoints(aMesh, F,
					 quad->edge[i],
					 quad->first[i],
					 quad->last[i]);

      // 					     quad->isEdgeForward[i]);
    }
  for (int i=2; i<4; i++)
    {
      quad->uv_edges[i] = LoadEdgePoints(aMesh, F,
					 quad->edge[i],
					 quad->last[i],
					 quad->first[i]);

      // 					     !quad->isEdgeForward[i]);
    }

  // 3 --- 2D normalized values on unit square [0..1][0..1]

  int nbdown = quad->nbPts[0];
  int nbright = quad->nbPts[1];
  quad->uv_grid  = new UVPtStruct[nbright*nbdown];

  UVPtStruct* uv_grid = quad->uv_grid;
  UVPtStruct* uv_e0   = quad->uv_edges[0];
  UVPtStruct* uv_e1   = quad->uv_edges[1];
  UVPtStruct* uv_e2   = quad->uv_edges[2];
  UVPtStruct* uv_e3   = quad->uv_edges[3];
  gp_Pnt2d a0 = pf[0];
  gp_Pnt2d a1 = pf[1];
  gp_Pnt2d a2 = pf[2];
  gp_Pnt2d a3 = pf[3];

  // nodes Id on edges

  int j = 0;
  for (int i=0; i<nbdown; i++)
    {
      int ij = j*nbdown +i;
      uv_grid[ij].nodeId = uv_e0[i].nodeId;
    }
  i = nbdown-1;
  for (int j=0; j<nbright; j++)
    {
      int ij = j*nbdown +i;
      uv_grid[ij].nodeId = uv_e1[j].nodeId;
    }
  j = nbright -1;
  for (int i=0; i<nbdown; i++)
    {
      int ij = j*nbdown +i;
      uv_grid[ij].nodeId = uv_e2[i].nodeId;
    }
  i = 0;
  for (int j=0; j<nbright; j++)
    {
      int ij = j*nbdown +i;
      uv_grid[ij].nodeId = uv_e3[j].nodeId;
    }

  // normalized 2d values on grid

  for (int i=0; i<nbdown; i++)
    for (int j=0; j<nbright; j++)
      {
	int ij = j*nbdown +i;
	// --- droite i cste : x = x0 + y(x1-x0)
	double x0 = uv_e0[i].normParam;              // bas - sud
	double x1 = uv_e2[i].normParam;              // haut - nord
	// --- droite j cste : y = y0 + x(y1-y0)
	double y0 = uv_e3[j].normParam;              // gauche-ouest
	double y1 = uv_e1[j].normParam;              // droite - est
	// --- intersection : x=x0+(y0+x(y1-y0))(x1-x0)
	double x=(x0+y0*(x1-x0))/(1-(y1-y0)*(x1-x0));
	double y=y0+x*(y1-y0);
	uv_grid[ij].x = x;
	uv_grid[ij].y = y;
	//MESSAGE("-xy-01 "<<x0<<" "<<x1<<" "<<y0<<" "<<y1);
	//MESSAGE("-xy-norm "<<i<<" "<<j<<" "<<x<<" "<<y);
      }

  // 4 --- projection on 2d domain (u,v)

  for (int i=0; i<nbdown; i++)
    for (int j=0; j<nbright; j++)
      {
	int ij = j*nbdown +i;
	double x = uv_grid[ij].x;
	double y = uv_grid[ij].y;
	double param_0 = uv_e0[0].param
	  + x*(uv_e0[nbdown-1].param -uv_e0[0].param);     // sud
	double param_2 = uv_e2[0].param
	  + x*(uv_e2[nbdown-1].param -uv_e2[0].param);     // nord
	double param_1 = uv_e1[0].param
	  + y*(uv_e1[nbright-1].param -uv_e1[0].param);    // est
	double param_3 = uv_e3[0].param
	  + y*(uv_e3[nbright-1].param -uv_e3[0].param);    // ouest

	//MESSAGE("params "<<param_0<<" "<<param_1<<" "<<param_2<<" "<<param_3);
	gp_Pnt2d p0 = c2d[0]->Value(param_0);
	gp_Pnt2d p1 = c2d[1]->Value(param_1);
	gp_Pnt2d p2 = c2d[2]->Value(param_2);
	gp_Pnt2d p3 = c2d[3]->Value(param_3);

	double u = (1-y)*p0.X() + x*p1.X() + y*p2.X() + (1-x)*p3.X();
	double v = (1-y)*p0.Y() + x*p1.Y() + y*p2.Y() + (1-x)*p3.Y();

  	u -= (1-x)*(1-y)*a0.X() + x*(1-y)*a1.X() + x*y*a2.X() + (1-x)*y*a3.X();
  	v -= (1-x)*(1-y)*a0.Y() + x*(1-y)*a1.Y() + x*y*a2.Y() + (1-x)*y*a3.Y();

	uv_grid[ij].u = u;
	uv_grid[ij].v = v;

	//MESSAGE("-uv- "<<i<<" "<<j<<" "<<uv_grid[ij].u<<" "<<uv_grid[ij].v);
      }
}

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

UVPtStruct* SMESH_Quadrangle_2D::LoadEdgePoints(SMESH_Mesh& aMesh,
						const TopoDS_Face& F,
						const TopoDS_Edge& E,
						double first,
						double last)
  // 						bool isForward)
{
  //MESSAGE("SMESH_Quadrangle_2D::LoadEdgePoints");

  Handle (SMDS_Mesh) meshDS = aMesh.GetMeshDS();

  // --- IDNodes of first and last Vertex

  TopoDS_Vertex VFirst, VLast;
  TopExp::Vertices(E, VFirst, VLast); // corresponds to f and l
  
  ASSERT(!VFirst.IsNull());
  SMESH_subMesh* firstSubMesh = aMesh.GetSubMesh(VFirst);
  const TColStd_ListOfInteger& lidf
    = firstSubMesh->GetSubMeshDS()->GetIDNodes();
  int idFirst= lidf.First();
  //SCRUTE(idFirst);
  
  ASSERT(!VLast.IsNull());
  SMESH_subMesh* lastSubMesh = aMesh.GetSubMesh(VLast);
  const TColStd_ListOfInteger& lidl
    = lastSubMesh->GetSubMeshDS()->GetIDNodes();
  int idLast= lidl.First();
  //SCRUTE(idLast);

  // --- edge internal IDNodes (relies on good order storage, not checked)

  int nbPoints = aMesh.GetSubMesh(E)->GetSubMeshDS()->NbNodes();
  //SCRUTE(nbPoints);
  UVPtStruct * uvslf = new UVPtStruct[nbPoints+2];
  
  double f,l;
  Handle(Geom2d_Curve) C2d = BRep_Tool::CurveOnSurface(E,F,f,l);
  
  const TColStd_ListOfInteger& indElt
    = aMesh.GetSubMesh(E)->GetSubMeshDS()->GetIDNodes();
  TColStd_ListIteratorOfListOfInteger ite(indElt);
  //SCRUTE(nbPoints);
  //SCRUTE(indElt.Extent());
  ASSERT(nbPoints == indElt.Extent());

  map<double,int> params;
  for (; ite.More(); ite.Next())
    {
      int nodeId = ite.Value();
      Handle (SMDS_MeshElement) elt = meshDS->FindNode(nodeId);
      Handle (SMDS_MeshNode) node = meshDS->GetNode(1, elt);
      Handle (SMDS_EdgePosition) epos
	= Handle (SMDS_EdgePosition)::DownCast(node->GetPosition());
      double param = epos->GetUParameter();
      params[param] = nodeId;
    }

  bool isForward = (((l-f)*(last-first)) > 0);
  double paramin = 0;
  double paramax = 0;
  if (isForward)
    {
      paramin = f;
      paramax = l;
      gp_Pnt2d p = C2d->Value(f);           // first point = Vertex Forward
      uvslf [0].x = p.X();
      uvslf [0].y = p.Y();
      uvslf [0].param = f;
      uvslf [0].nodeId = idFirst;
      //MESSAGE("__ f "<<f<<" "<<uvslf[0].x <<" "<<uvslf[0].y);
      map<double,int>::iterator itp = params.begin();
      for (int i = 1; i <= nbPoints; i++)   // nbPoints internal
	{
	  double param = (*itp).first;
	  int nodeId = (*itp).second;
	  gp_Pnt2d p = C2d->Value(param);
	  uvslf [i].x = p.X();
	  uvslf [i].y = p.Y();
	  uvslf[i].param = param;
	  uvslf[i].nodeId = nodeId;
	  //MESSAGE("__ "<<i<<" "<<param<<" "<<uvslf[i].x <<" "<<uvslf[i].y);
	  itp++;
	}
      p = C2d->Value(l);                    // last point = Vertex Reversed
      uvslf [nbPoints+1].x = p.X();
      uvslf [nbPoints+1].y = p.Y();
      uvslf [nbPoints+1].param = l;
      uvslf [nbPoints+1].nodeId = idLast;
      //MESSAGE("__ l "<<l<<" "<<uvslf[nbPoints+1].x <<" "<<uvslf[nbPoints+1].y);
    }
  else 
    {
      paramin = l;
      paramax = f;
      gp_Pnt2d p = C2d->Value(l);           // first point = Vertex Reversed
      uvslf [0].x = p.X();
      uvslf [0].y = p.Y();
      uvslf [0].param = l;
      uvslf [0].nodeId = idLast;
      //MESSAGE("__ l "<<l<<" "<<uvslf[0].x <<" "<<uvslf[0].y);
      map<double,int>::reverse_iterator itp = params.rbegin();
      for (int j = nbPoints; j >= 1; j--)     // nbPoints internal
	{
	  double param = (*itp).first;
	  int nodeId = (*itp).second;
	  int i = nbPoints +1 -j;
	  gp_Pnt2d p = C2d->Value(param);
	  uvslf [i].x = p.X();
	  uvslf [i].y = p.Y();
	  uvslf[i].param = param;
	  uvslf[i].nodeId = nodeId;
	  //MESSAGE("__ "<<i<<" "<<param<<" "<<uvslf[i].x <<" "<<uvslf[i].y);
	  itp++;
	}
      p = C2d->Value(f);                    // last point = Vertex Forward
      uvslf [nbPoints+1].x = p.X();
      uvslf [nbPoints+1].y = p.Y();
      uvslf [nbPoints+1].param = f;
      uvslf [nbPoints+1].nodeId = idFirst;
      //MESSAGE("__ f "<<f<<" "<<uvslf[nbPoints+1].x <<" "<<uvslf[nbPoints+1].y);
    }

  ASSERT(paramin != paramax);
  for (int i = 0; i< nbPoints+2; i++)
    {
      uvslf[i].normParam = (uvslf[i].param -paramin)/(paramax -paramin);
      //SCRUTE(uvslf[i].normParam);
    }

  return uvslf;
}

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

ostream & SMESH_Quadrangle_2D::SaveTo(ostream & save)
{
  return save << this;
}

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

istream & SMESH_Quadrangle_2D::LoadFrom(istream & load)
{
  return load >> (*this);
}

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

ostream & operator << (ostream & save, SMESH_Quadrangle_2D & hyp)
{
  return save;
}

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

istream & operator >> (istream & load, SMESH_Quadrangle_2D & hyp)
{
  return load;
}