// Copyright (c) 2015-2021 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#include <RWObj_CafWriter.hxx>

#include <Message.hxx>
#include <Message_LazyProgressScope.hxx>
#include <OSD_OpenFile.hxx>
#include <OSD_Path.hxx>
#include <RWMesh_FaceIterator.hxx>
#include <RWMesh_MaterialMap.hxx>
#include <RWObj_ObjMaterialMap.hxx>
#include <RWObj_ObjWriterContext.hxx>
#include <Standard_CLocaleSentry.hxx>
#include <TDocStd_Document.hxx>
#include <TDataStd_Name.hxx>
#include <XCAFDoc_DocumentTool.hxx>
#include <XCAFDoc_ShapeTool.hxx>
#include <XCAFPrs_DocumentExplorer.hxx>

IMPLEMENT_STANDARD_RTTIEXT(RWObj_CafWriter, Standard_Transient)

namespace
{
  //! Trivial cast.
  inline Graphic3d_Vec3 objXyzToVec (const gp_XYZ& thePnt)
  {
    return Graphic3d_Vec3 ((float )thePnt.X(), (float )thePnt.Y(), (float )thePnt.Z());
  }

  //! Trivial cast.
  inline Graphic3d_Vec2 objXyToVec (const gp_XY& thePnt)
  {
    return Graphic3d_Vec2 ((float )thePnt.X(), (float )thePnt.Y());
  }

  //! Read name attribute.
  static TCollection_AsciiString readNameAttribute (const TDF_Label& theRefLabel)
  {
    Handle(TDataStd_Name) aNodeName;
    if (!theRefLabel.FindAttribute (TDataStd_Name::GetID(), aNodeName))
    {
      return TCollection_AsciiString();
    }
    return TCollection_AsciiString (aNodeName->Get());
  }
}

//================================================================
// Function : Constructor
// Purpose  :
//================================================================
RWObj_CafWriter::RWObj_CafWriter (const TCollection_AsciiString& theFile)
: myFile (theFile)
{
  // OBJ file format doesn't define length units;
  // Y-up coordinate system is most commonly used (but also undefined)
  //myCSTrsf.SetOutputCoordinateSystem (RWMesh_CoordinateSystem_negZfwd_posYup);
}

//================================================================
// Function : Destructor
// Purpose  :
//================================================================
RWObj_CafWriter::~RWObj_CafWriter()
{
  //
}

//================================================================
// Function : toSkipFaceMesh
// Purpose  :
//================================================================
Standard_Boolean RWObj_CafWriter::toSkipFaceMesh (const RWMesh_FaceIterator& theFaceIter)
{
  return theFaceIter.IsEmptyMesh();
}

// =======================================================================
// function : Perform
// purpose  :
// =======================================================================
bool RWObj_CafWriter::Perform (const Handle(TDocStd_Document)& theDocument,
                               const TColStd_IndexedDataMapOfStringString& theFileInfo,
                               const Message_ProgressRange& theProgress)
{
  TDF_LabelSequence aRoots;
  Handle(XCAFDoc_ShapeTool) aShapeTool = XCAFDoc_DocumentTool::ShapeTool (theDocument->Main());
  aShapeTool->GetFreeShapes (aRoots);
  return Perform (theDocument, aRoots, NULL, theFileInfo, theProgress);
}

// =======================================================================
// function : Perform
// purpose  :
// =======================================================================
bool RWObj_CafWriter::Perform (const Handle(TDocStd_Document)& theDocument,
                               const TDF_LabelSequence& theRootLabels,
                               const TColStd_MapOfAsciiString* theLabelFilter,
                               const TColStd_IndexedDataMapOfStringString& theFileInfo,
                               const Message_ProgressRange& theProgress)
{
  TCollection_AsciiString aFolder, aFileName, aFullFileNameBase, aShortFileNameBase, aFileExt;
  OSD_Path::FolderAndFileFromPath (myFile, aFolder, aFileName);
  OSD_Path::FileNameAndExtension (aFileName, aShortFileNameBase, aFileExt);

  if (theRootLabels.IsEmpty()
  || (theLabelFilter != NULL && theLabelFilter->IsEmpty()))
  {
    Message::SendFail ("Nothing to export into OBJ file");
    return false;
  }

  Standard_Integer aNbNodesAll = 0, aNbElemsAll = 0;
  Standard_Real aNbPEntities = 0; // steps for progress range
  bool toCreateMatFile = false;
  for (XCAFPrs_DocumentExplorer aDocExplorer (theDocument, theRootLabels, XCAFPrs_DocumentExplorerFlags_OnlyLeafNodes);
       aDocExplorer.More(); aDocExplorer.Next())
  {
    const XCAFPrs_DocumentNode& aDocNode = aDocExplorer.Current();
    if (theLabelFilter != NULL
    && !theLabelFilter->Contains (aDocNode.Id))
    {
      continue;
    }

    for (RWMesh_FaceIterator aFaceIter (aDocNode.RefLabel, aDocNode.Location, true, aDocNode.Style); aFaceIter.More(); aFaceIter.Next())
    {
      if (toSkipFaceMesh (aFaceIter))
      {
        continue;
      }

      addFaceInfo (aFaceIter, aNbNodesAll, aNbElemsAll, aNbPEntities, toCreateMatFile);
    }
  }
  if (aNbNodesAll == 0
   || aNbElemsAll == 0)
  {
    Message::SendFail ("No mesh data to save");
    return false;
  }

  TCollection_AsciiString aMatFileNameShort = aShortFileNameBase + ".mtl";
  const TCollection_AsciiString aMatFileNameFull  = !aFolder.IsEmpty() ? aFolder + aMatFileNameShort : aMatFileNameShort;
  if (!toCreateMatFile)
  {
    aMatFileNameShort.Clear();
  }

  Standard_CLocaleSentry  aLocaleSentry;
  RWObj_ObjWriterContext  anObjFile(myFile);
  RWObj_ObjMaterialMap    aMatMgr  (aMatFileNameFull);
  aMatMgr.SetDefaultStyle (myDefaultStyle);
  if (!anObjFile.IsOpened()
   || !anObjFile.WriteHeader (aNbNodesAll, aNbElemsAll, aMatFileNameShort, theFileInfo))
  {
    return false;
  }

  int aRootDepth = 0;
  if (theRootLabels.Size() == 1)
  {
    TDF_Label aRefLabel = theRootLabels.First();
    XCAFDoc_ShapeTool::GetReferredShape (theRootLabels.First(), aRefLabel);
    TCollection_AsciiString aRootName = readNameAttribute (aRefLabel);
    if (aRootName.EndsWith (".obj"))
    {
      // workaround import/export of .obj file
      aRootDepth = 1;
    }
  }

  // simple global progress sentry - ignores size of node and index data
  const Standard_Real aPatchStep = 2048.0; // about 100 KiB
  Message_LazyProgressScope aPSentry (theProgress, "OBJ export", aNbPEntities, aPatchStep);

  bool isDone = true;
  for (XCAFPrs_DocumentExplorer aDocExplorer (theDocument, theRootLabels, XCAFPrs_DocumentExplorerFlags_OnlyLeafNodes);
       aDocExplorer.More() && !aPSentry.IsAborted(); aDocExplorer.Next())
  {
    const XCAFPrs_DocumentNode& aDocNode = aDocExplorer.Current();
    if (theLabelFilter != NULL
    && !theLabelFilter->Contains (aDocNode.Id))
    {
      continue;
    }

    TCollection_AsciiString aName = readNameAttribute (aDocNode.RefLabel);
    for (int aParentIter = aDocExplorer.CurrentDepth() - 1; aParentIter >= aRootDepth; --aParentIter)
    {
      const TCollection_AsciiString aParentName = readNameAttribute (aDocExplorer.Current (aParentIter).RefLabel);
      if (!aParentName.IsEmpty())
      {
        aName = aParentName + "/" + aName;
      }
    }

    if (!writeShape (anObjFile, aMatMgr, aPSentry, aDocNode.RefLabel, aDocNode.Location, aDocNode.Style, aName))
    {
      isDone = false;
      break;
    }
  }

  const bool isClosed = anObjFile.Close();
  if (isDone && !isClosed)
  {
    Message::SendFail (TCollection_AsciiString ("Failed to write OBJ file\n") + myFile);
    return false;
  }
  return isDone && !aPSentry.IsAborted();
}

// =======================================================================
// function : addFaceInfo
// purpose  :
// =======================================================================
void RWObj_CafWriter::addFaceInfo (const RWMesh_FaceIterator& theFace,
                                   Standard_Integer& theNbNodes,
                                   Standard_Integer& theNbElems,
                                   Standard_Real& theNbProgressSteps,
                                   Standard_Boolean& theToCreateMatFile)
{
  theNbNodes += theFace.NbNodes();
  theNbElems += theFace.NbTriangles();

  theNbProgressSteps += theFace.NbNodes();
  theNbProgressSteps += theFace.NbTriangles();
  if (theFace.HasNormals())
  {
    theNbProgressSteps += theFace.NbNodes();
  }
  if (theFace.HasTexCoords()) //&& !theFace.FaceStyle().Texture().IsEmpty()
  {
    theNbProgressSteps += theFace.NbNodes();
  }

  theToCreateMatFile = theToCreateMatFile
                   ||  theFace.HasFaceColor()
                   || (!theFace.FaceStyle().BaseColorTexture().IsNull() && theFace.HasTexCoords());
}

// =======================================================================
// function : writeShape
// purpose  :
// =======================================================================
bool RWObj_CafWriter::writeShape (RWObj_ObjWriterContext&        theWriter,
                                  RWObj_ObjMaterialMap&          theMatMgr,
                                  Message_LazyProgressScope&     thePSentry,
                                  const TDF_Label&               theLabel,
                                  const TopLoc_Location&         theParentTrsf,
                                  const XCAFPrs_Style&           theParentStyle,
                                  const TCollection_AsciiString& theName)
{
  bool toCreateGroup = true;
  for (RWMesh_FaceIterator aFaceIter (theLabel, theParentTrsf, true, theParentStyle); aFaceIter.More() && !thePSentry.IsAborted(); aFaceIter.Next())
  {
    if (toSkipFaceMesh (aFaceIter))
    {
      continue;
    }

    ++theWriter.NbFaces;
    {
      const bool hasNormals   = aFaceIter.HasNormals();
      const bool hasTexCoords = aFaceIter.HasTexCoords(); //&& !aFaceIter.FaceStyle().Texture().IsEmpty();
      if (theWriter.NbFaces != 1)
      {
        toCreateGroup = toCreateGroup
                     || hasNormals   != theWriter.HasNormals()
                     || hasTexCoords != theWriter.HasTexCoords();
      }
      theWriter.SetNormals  (hasNormals);
      theWriter.SetTexCoords(hasTexCoords);
    }

    if (toCreateGroup
    && !theWriter.WriteGroup (theName))
    {
      return false;
    }
    toCreateGroup = false;

    TCollection_AsciiString aMatName;
    if (aFaceIter.HasFaceColor()
    || !aFaceIter.FaceStyle().BaseColorTexture().IsNull())
    {
      aMatName = theMatMgr.AddMaterial (aFaceIter.FaceStyle());
    }
    if (aMatName != theWriter.ActiveMaterial())
    {
      theWriter.WriteActiveMaterial (aMatName);
    }

    // write nodes
    if (!writePositions (theWriter, thePSentry, aFaceIter))
    {
      return false;
    }

    // write normals
    if (theWriter.HasNormals()
    && !writeNormals (theWriter, thePSentry, aFaceIter))
    {
      return false;
    }

    if (theWriter.HasTexCoords()
    && !writeTextCoords (theWriter, thePSentry, aFaceIter))
    {
      return false;
    }

    if (!writeIndices (theWriter, thePSentry, aFaceIter))
    {
      return false;
    }
    theWriter.FlushFace (aFaceIter.NbNodes());
  }
  return true;
}

// =======================================================================
// function : writePositions
// purpose  :
// =======================================================================
bool RWObj_CafWriter::writePositions (RWObj_ObjWriterContext&    theWriter,
                                      Message_LazyProgressScope& thePSentry,
                                      const RWMesh_FaceIterator& theFace)
{
  const Standard_Integer aNodeUpper = theFace.NodeUpper();
  for (Standard_Integer aNodeIter = theFace.NodeLower(); aNodeIter <= aNodeUpper && thePSentry.More(); ++aNodeIter, thePSentry.Next())
  {
    gp_XYZ aNode = theFace.NodeTransformed (aNodeIter).XYZ();
    myCSTrsf.TransformPosition (aNode);
    if (!theWriter.WriteVertex (objXyzToVec (aNode)))
    {
      return false;
    }
  }
  return true;
}

// =======================================================================
// function : writeNormals
// purpose  :
// =======================================================================
bool RWObj_CafWriter::writeNormals (RWObj_ObjWriterContext&    theWriter,
                                    Message_LazyProgressScope& thePSentry,
                                    const RWMesh_FaceIterator& theFace)
{
  const Standard_Integer aNodeUpper = theFace.NodeUpper();
  for (Standard_Integer aNodeIter = theFace.NodeLower(); aNodeIter <= aNodeUpper && thePSentry.More(); ++aNodeIter, thePSentry.Next())
  {
    const gp_Dir aNormal = theFace.NormalTransformed (aNodeIter);
    Graphic3d_Vec3 aNormVec3 = objXyzToVec (aNormal.XYZ());
    myCSTrsf.TransformNormal (aNormVec3);
    if (!theWriter.WriteNormal (aNormVec3))
    {
      return false;
    }
  }
  return true;
}

// =======================================================================
// function : writeTextCoords
// purpose  :
// =======================================================================
bool RWObj_CafWriter::writeTextCoords (RWObj_ObjWriterContext&    theWriter,
                                       Message_LazyProgressScope& thePSentry,
                                       const RWMesh_FaceIterator& theFace)
{
  const Standard_Integer aNodeUpper = theFace.NodeUpper();
  for (Standard_Integer aNodeIter = theFace.NodeLower(); aNodeIter <= aNodeUpper && thePSentry.More(); ++aNodeIter, thePSentry.Next())
  {
    gp_Pnt2d aTexCoord = theFace.NodeTexCoord (aNodeIter);
    if (!theWriter.WriteTexCoord (objXyToVec (aTexCoord.XY())))
    {
      return false;
    }
  }
  return true;
}

// =======================================================================
// function : writeIndices
// purpose  :
// =======================================================================
bool RWObj_CafWriter::writeIndices (RWObj_ObjWriterContext&    theWriter,
                                    Message_LazyProgressScope& thePSentry,
                                    const RWMesh_FaceIterator& theFace)
{
  const Standard_Integer anElemLower = theFace.ElemLower();
  const Standard_Integer anElemUpper = theFace.ElemUpper();
  for (Standard_Integer anElemIter = anElemLower; anElemIter <= anElemUpper && thePSentry.More(); ++anElemIter, thePSentry.Next())
  {
    const Poly_Triangle aTri = theFace.TriangleOriented (anElemIter);
    if (!theWriter.WriteTriangle (Graphic3d_Vec3i (aTri(1), aTri(2), aTri(3)) - Graphic3d_Vec3i (anElemLower)))
    {
      return false;
    }
  }
  return true;
}