// Copyright (c) 2015  GeometryFactory (France). All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// 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.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
// SPDX-License-Identifier: GPL-3.0+
//
// Author(s)     : Sebastien Loriot <sebastien.loriot@cgal.org>,
//                 Jane Tournois
//

#include <CGAL/Mesh_3/io_signature.h>
#include "Scene_c3t3_item.h"
#include <QtCore/qglobal.h>

#ifdef USE_SURFACE_MESH
#include "Scene_surface_mesh_item.h"
#else
#include "Polyhedron_type.h"
#include "Scene_polyhedron_item.h"
#include <CGAL/boost/graph/graph_traits_Polyhedron_3.h>
#endif
#include "Scene_polylines_item.h"

#include <CGAL/Three/Polyhedron_demo_plugin_helper.h>
#include <CGAL/Three/Polyhedron_demo_io_plugin_interface.h>

#include <QApplication>
#include <QMessageBox>
#include <QMainWindow>
#include <QFileDialog>
#include <QString>

#include <fstream>

#include <boost/graph/graph_traits.hpp>
#include <boost/unordered_map.hpp>

#include <CGAL/boost/graph/properties.h>
#include <CGAL/boost/graph/Euler_operations.h>
#include <CGAL/property_map.h>
#include <CGAL/IO/Complex_3_in_triangulation_3_to_vtk.h>
#include <CGAL/IO/vtk_io.h>

#include <vtkSmartPointer.h>
#include <vtkDataSetReader.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkPolyDataWriter.h>
#include <vtkUnstructuredGrid.h>
#include <vtkXMLUnstructuredGridReader.h>
#include <vtkXMLPolyDataWriter.h>
#include <vtkPolyData.h>
#include <vtkIdTypeArray.h>
#include <vtkFieldData.h>
#include <vtkFloatArray.h>
#include <vtkDoubleArray.h>
#include <vtkCell.h>
#include <vtkCellData.h>
#include <vtkIdList.h>
#include <vtkAppendFilter.h>
#include <vtkSphereSource.h>
#include <vtkVersion.h>
#include <vtkXMLUnstructuredGridWriter.h>
#include <vtkPoints.h>
#include <vtkCellArray.h>
#include <vtkType.h>
#include <vtkCommand.h>
#include <vtkXMLUnstructuredGridWriter.h>

#include <CGAL/Polygon_mesh_processing/internal/named_function_params.h>
#include <CGAL/Polygon_mesh_processing/internal/named_params_helper.h>

#ifdef USE_SURFACE_MESH
typedef Scene_surface_mesh_item Scene_facegraph_item;
#else
typedef Scene_polyhedron_item Scene_facegraph_item;
#endif
typedef Scene_facegraph_item::Face_graph FaceGraph;
typedef boost::property_traits<boost::property_map<FaceGraph, 
CGAL::vertex_point_t>::type>::value_type Point;




namespace CGAL{

  class ErrorObserverVtk : public vtkCommand
  {
  public:
    ErrorObserverVtk() :
      Error(false),
      Warning(false),
      ErrorMessage(""),
      WarningMessage("") {}
    static ErrorObserverVtk *New() { return new ErrorObserverVtk; }

    bool GetError() const          { return this->Error; }
    bool GetWarning() const        { return this->Warning; }
    std::string GetErrorMessage()   { return ErrorMessage; }
    std::string GetWarningMessage() { return WarningMessage; }

    void Clear()
    {
      this->Error = false;
      this->Warning = false;
      this->ErrorMessage = "";
      this->WarningMessage = "";
    }
    virtual void Execute(vtkObject *vtkNotUsed(caller),
                         unsigned long event,
                         void *calldata)
    {
      switch (event)
      {
      case vtkCommand::ErrorEvent:
        ErrorMessage = static_cast<char *>(calldata);
        this->Error = true;
        break;
      case vtkCommand::WarningEvent:
        WarningMessage = static_cast<char *>(calldata);
        this->Warning = true;
        break;
      }
    }

  private:
    bool        Error;
    bool        Warning;
    std::string ErrorMessage;
    std::string WarningMessage;
  };

  template <typename TM>
  bool vtkPointSet_to_polygon_mesh(vtkPointSet* poly_data,
                                   TM& tmesh)
  {
    typedef typename boost::property_map<TM, CGAL::vertex_point_t>::type VPMap;
    typedef typename boost::property_map_value<TM, CGAL::vertex_point_t>::type Point_3;
    typedef typename boost::graph_traits<TM>::vertex_descriptor vertex_descriptor;

    VPMap vpmap = get(CGAL::vertex_point, tmesh);

    // get nb of points and cells
    vtkIdType nb_points = poly_data->GetNumberOfPoints();
    vtkIdType nb_cells = poly_data->GetNumberOfCells();

    //extract points
    std::vector<vertex_descriptor> vertex_map(nb_points);
    for (vtkIdType i = 0; i<nb_points; ++i)
    {
      double coords[3];
      poly_data->GetPoint(i, coords);

      vertex_descriptor v = add_vertex(tmesh);
      put(vpmap, v, Point_3(coords[0], coords[1], coords[2]));
      vertex_map[i]=v;
    }

    //extract cells
    for (vtkIdType i = 0; i<nb_cells; ++i)
    {
      vtkCell* cell_ptr = poly_data->GetCell(i);

      vtkIdType nb_vertices = cell_ptr->GetNumberOfPoints();
      if (nb_vertices < 3)
        return false;
      std::vector<vertex_descriptor> vr(nb_vertices);
      for (vtkIdType k=0; k<nb_vertices; ++k)
        vr[k]=vertex_map[cell_ptr->GetPointId(k)];

      CGAL::Euler::add_face(vr, tmesh);
    }
    return true;
  }

  template <class Point_3>
  void extract_segments_from_vtkPointSet(vtkPointSet* poly_data,
                                         std::vector< std::vector<Point_3> >& segments)
  {
    // get nb of points and cells
    vtkIdType nb_points = poly_data->GetNumberOfPoints();
    vtkIdType nb_cells = poly_data->GetNumberOfCells();

    //extract points
    std::vector<Point_3> point_map(nb_points);
    for (vtkIdType i = 0; i<nb_points; ++i)
    {
      double coords[3];
      poly_data->GetPoint(i, coords);
      point_map[i]=Point_3(coords[0], coords[1], coords[2]);
    }

    //extract segments
    for (vtkIdType i = 0; i<nb_cells; ++i)
    {
      vtkCell* cell_ptr = poly_data->GetCell(i);

      vtkIdType nb_vertices = cell_ptr->GetNumberOfPoints();
      if (nb_vertices !=2) continue;
      segments.push_back( std::vector<Point_3>() );
      segments.back().push_back(point_map[cell_ptr->GetPointId(0)]);
      segments.back().push_back(point_map[cell_ptr->GetPointId(1)]);
    }
  }

  template<typename VtkWriter, typename PM>
  void polygon_mesh_to_vtkUnstructured(const PM& pmesh,//PolygonMesh
                                       const char* filename)
  {
    typedef typename boost::graph_traits<PM>::vertex_descriptor   vertex_descriptor;
    typedef typename boost::graph_traits<PM>::face_descriptor     face_descriptor;
    typedef typename boost::graph_traits<PM>::halfedge_descriptor halfedge_descriptor;

    typedef typename boost::property_map<PM, CGAL::vertex_point_t>::const_type VPMap;
    typedef typename boost::property_map_value<PM, CGAL::vertex_point_t>::type Point_3;
    VPMap vpmap = get(CGAL::vertex_point, pmesh);

    vtkPoints* const vtk_points = vtkPoints::New();
    vtkCellArray* const vtk_cells = vtkCellArray::New();

    vtk_points->Allocate(num_vertices(pmesh));
    vtk_cells->Allocate(num_faces(pmesh));

    std::map<vertex_descriptor, vtkIdType> Vids;
    vtkIdType inum = 0;

    BOOST_FOREACH(vertex_descriptor v, vertices(pmesh))
    {
      const Point_3& p = get(vpmap, v);
      vtk_points->InsertNextPoint(CGAL::to_double(p.x()),
                                  CGAL::to_double(p.y()),
                                  CGAL::to_double(p.z()));
      Vids[v] = inum++;
    }
    BOOST_FOREACH(face_descriptor f, faces(pmesh))
    {
      vtkIdList* cell = vtkIdList::New();
      BOOST_FOREACH(halfedge_descriptor h,
                    halfedges_around_face(halfedge(f, pmesh), pmesh))
      {
        cell->InsertNextId(Vids[target(h, pmesh)]);
      }
      vtk_cells->InsertNextCell(cell);
      cell->Delete();
    }

    vtkSmartPointer<vtkPolyData> polydata =
      vtkSmartPointer<vtkPolyData>::New();

    polydata->SetPoints(vtk_points);
    vtk_points->Delete();

    polydata->SetPolys(vtk_cells);
    vtk_cells->Delete();

    // Combine the two data sets
    //vtkSmartPointer<vtkAppendFilter> appendFilter =
    //  vtkSmartPointer<vtkAppendFilter>::New();
    //appendFilter->AddInputData(polydata);
    //appendFilter->Update();

    //vtkSmartPointer<vtkPolyData> unstructuredGrid =
    //  vtkSmartPointer<vtkPolyData>::New();
    //unstructuredGrid->ShallowCopy(appendFilter->GetOutput());

    // Write the unstructured grid
    vtkSmartPointer<VtkWriter> writer =
      vtkSmartPointer<VtkWriter>::New();
    writer->SetFileName(filename);
    writer->SetInputData(polydata);
    writer->Write();
  }
}//end namespace CGAL


class Polyhedron_demo_vtk_plugin :
  public QObject,
  public CGAL::Three::Polyhedron_demo_io_plugin_interface
{
  Q_OBJECT
  Q_INTERFACES(CGAL::Three::Polyhedron_demo_io_plugin_interface)
  Q_PLUGIN_METADATA(IID "com.geometryfactory.PolyhedronDemo.IOPluginInterface/1.0")

public:
  typedef boost::graph_traits<FaceGraph>::vertex_descriptor vertex_descriptor;
  typedef boost::graph_traits<FaceGraph>::face_descriptor face_descriptor;

#ifdef USE_SURFACE_MESH
  QString nameFilters() const {
    return "VTK PolyData files Surface_mesh (*.vtk);; VTK XML PolyData Surface_mesh (*.vtp);; VTK XML UnstructuredGrid Surface_mesh(*.vtu)"; }
  QString name() const { return "vtk_sm_plugin"; }
#else
  QString nameFilters() const {
    return "VTK PolyData files Polyhedron (*.vtk);; VTK XML PolyData Polyhedron (*.vtp);; VTK XML UnstructuredGrid Polyhedron(*.vtu)"; }
  QString name() const { return "vtk_plugin"; }
#endif
  bool canSave(const CGAL::Three::Scene_item* item)
  {
    return (qobject_cast<const Scene_facegraph_item*>(item)
            || qobject_cast<const Scene_c3t3_item*>(item));
  }
  
  
  bool save(const CGAL::Three::Scene_item* item, QFileInfo fileinfo)
  {
    std::string extension = fileinfo.suffix().toLower().toStdString();
    if ( extension != "vtk" && extension != "vtp" && extension != "vtu")
      return false;

    std::string output_filename = fileinfo.absoluteFilePath().toStdString();

    const Scene_facegraph_item* poly_item =
      qobject_cast<const Scene_facegraph_item*>(item);

    if (poly_item)
    {
      if (extension != "vtp")
        CGAL::polygon_mesh_to_vtkUnstructured<vtkPolyDataWriter>(
          *poly_item->polyhedron(),
          output_filename.data());
      else
      {
        const FaceGraph* mesh = poly_item->face_graph();
        std::ofstream os(output_filename.data());
        os << std::setprecision(16);
        //write header
        CGAL::write_polydata(os, *mesh);
      }
    }
    else
    {
      const Scene_c3t3_item* c3t3_item =
          qobject_cast<const Scene_c3t3_item*>(item);
      if(!c3t3_item || extension != "vtu")
        return false;
      
      std::ofstream os(output_filename.data());
      os << std::setprecision(16);
      const C3t3& c3t3 = c3t3_item->c3t3();
      
      CGAL::write_unstructured_grid_3(os, c3t3);
    }
    return true;
  }

  bool canLoad() const { return true; }

  template <class vtkReader>
  vtkSmartPointer<vtkReader>
  read_vtk_file(const std::string& input_filename,
                vtkSmartPointer<CGAL::ErrorObserverVtk> errorObserver)
  {
    vtkSmartPointer<vtkReader> reader = vtkSmartPointer<vtkReader>::New();
    reader->AddObserver(vtkCommand::ErrorEvent, errorObserver);
    reader->AddObserver(vtkCommand::WarningEvent, errorObserver);
    reader->SetFileName(input_filename.data());
    reader->Update();
    return reader;
  }

  CGAL::Three::Scene_item* load(QFileInfo fileinfo)
  {
    std::string extension=fileinfo.suffix().toLower().toStdString();
    if (extension != "vtk" && extension != "vtp" && extension != "vtu")
      return 0;

    std::string fname = fileinfo.absoluteFilePath().toStdString();

    FaceGraph* poly = new FaceGraph();
    // Try to read .vtk in a facegraph
    vtkSmartPointer<vtkPointSet> data;
    vtkSmartPointer<CGAL::ErrorObserverVtk> obs =
      vtkSmartPointer<CGAL::ErrorObserverVtk>::New();

    if (extension=="vtp")
      data = read_vtk_file<vtkXMLPolyDataReader>(fname,obs)
              ->GetOutput();
    else
     if (extension=="vtu")
       data = read_vtk_file<vtkXMLUnstructuredGridReader>(fname,obs)
                ->GetOutput();
     else{
       //read non-XML data
       vtkSmartPointer<vtkDataSetReader> reader =
         read_vtk_file<vtkDataSetReader>(fname,obs);
       data = vtkPolyData::SafeDownCast(reader->GetOutput());
       if (!data)
        data = vtkUnstructuredGrid::SafeDownCast(reader->GetOutput());
     }

    if (obs->GetError())
    {
      QMessageBox msgBox;
      msgBox.setText("This type of data can't be opened");
      msgBox.setInformativeText(QString("VTK error message :\n")
        .append(QString(obs->GetErrorMessage().data())));
      msgBox.setStandardButtons(QMessageBox::Ok);
      msgBox.setIcon(QMessageBox::Critical);
      msgBox.exec();
      return NULL;
    }
    if (obs->GetWarning())
    {
      QMessageBox msgBox;
      msgBox.setText("This file generates a warning");
      msgBox.setInformativeText(QString("VTK warning message :\n")
        .append(QString(obs->GetWarningMessage().data())));
      msgBox.setStandardButtons(QMessageBox::Ok);
      msgBox.setIcon(QMessageBox::Warning);
      msgBox.exec();
    }
    if (obs->GetError())
    {
      QMessageBox msgBox;
      msgBox.setText("This type of data can't be opened");
      msgBox.setInformativeText(QString("VTK error message :\n")
        .append(QString(obs->GetErrorMessage().data())));
      msgBox.setStandardButtons(QMessageBox::Ok);
      msgBox.setIcon(QMessageBox::Critical);
      msgBox.exec();
      return NULL;
    }
    if (obs->GetWarning())
    {
      QMessageBox msgBox;
      msgBox.setText("This file generates a warning");
      msgBox.setInformativeText(QString("VTK warning message :\n")
        .append(QString(obs->GetWarningMessage().data())));
      msgBox.setStandardButtons(QMessageBox::Ok);
      msgBox.setIcon(QMessageBox::Warning);
      msgBox.exec();
    }

    if (CGAL::vtkPointSet_to_polygon_mesh(data, *poly))
    {
      Scene_facegraph_item* poly_item = new Scene_facegraph_item(poly);
      poly_item->setName(fileinfo.fileName());
      return poly_item;
    }
    else{
      // extract only segments
      std::vector< std::vector<Point> > segments;
      extract_segments_from_vtkPointSet(data,segments);
      if (segments.empty()) return NULL; /// TODO handle point sets
      Scene_polylines_item* polyline_item = new Scene_polylines_item();
      polyline_item->setName(fileinfo.fileName());
      BOOST_FOREACH(const std::vector<Point>& segment, segments)
        polyline_item->polylines.push_back(segment);
      return polyline_item;
    }
    return NULL;
  }
}; // end Polyhedron_demo_vtk_plugin


#include "VTK_io_plugin.moc"