/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
#ifndef itkMeshFileReader_h
#define itkMeshFileReader_h

#include "itkMeshFileReaderException.h"
#include "itkMacro.h"
#include "itkHexahedronCell.h"
#include "itkLineCell.h"
#include "itkPolyLineCell.h"
#include "itkMeshIOBase.h"
#include "itkMeshSource.h"
#include "itkPolygonCell.h"
#include "itkQuadrilateralCell.h"
#include "itkQuadraticEdgeCell.h"
#include "itkQuadraticTriangleCell.h"
#include "itkTetrahedronCell.h"
#include "itkTriangleCell.h"
#include "itkVertexCell.h"

#include "itkDefaultConvertPixelTraits.h"
#include "itkMeshConvertPixelTraits.h"

namespace itk
{

/**
 * \class MeshFileReader
 * \brief Mesh source that reads mesh data from a single file.
 *
 * This source object is a general filter to read data from
 * a variety of file formats. It works with a MeshIOBase subclass
 * to actually do the reading of the data. Object factory machinery
 * can be used to automatically create the MeshIOBase, or the
 * MeshIOBase can be manually created and set.
 *
 * TOutputMesh is the type expected by the external users of the
 * filter. If data stored in the file is stored in a different format
 * then specified by TOutputMesh, than this filter converts data
 * between the file type and the external expected type.  The
 * ConvertTraits template argument is used to do the conversion.
 *
 * A Pluggable factory pattern is used this allows different kinds of readers
 * to be registered (even at run time) without having to modify the
 * code in this class. Normally just setting the FileName with the
 * appropriate suffix is enough to get the reader to instantiate the
 * correct MeshIO and read the file properly. However, some files have
 * no accepted suffix, so you will have to
 * manually create the MeshIO instance of the write type.
 *
 * \sa MeshIOBase
 *
 * \ingroup IOFilters
 * \ingroup ITKIOMeshBase
 *
 * \author Wanlin Zhu. University of New South Wales, Australia.
 *
 * \sphinx
 * \sphinxexample{IO/Mesh/ReadMesh,Read Mesh}
 * \endsphinx
 */

template <typename TOutputMesh,
          typename ConvertPointPixelTraits = MeshConvertPixelTraits<typename TOutputMesh::PixelType>,
          typename ConvertCellPixelTraits = MeshConvertPixelTraits<typename TOutputMesh::CellPixelType>>
class ITK_TEMPLATE_EXPORT MeshFileReader : public MeshSource<TOutputMesh>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(MeshFileReader);

  /** Standard class type aliases. */
  using Self = MeshFileReader;
  using Superclass = MeshSource<TOutputMesh>;
  using ConstPointer = SmartPointer<const Self>;
  using Pointer = SmartPointer<Self>;

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

  /** \see LightObject::GetNameOfClass() */
  itkOverrideGetNameOfClassMacro(MeshFileReader);

  /** Define output mesh types */
  using OutputMeshType = TOutputMesh;
  using OutputCoordRepType = typename OutputMeshType::CoordRepType;
  using OutputPointPixelType = typename OutputMeshType::PixelType;
  using OutputCellPixelType = typename OutputMeshType::CellPixelType;
  using OutputPointType = typename OutputMeshType::PointType;
  using OutputPointIdentifier = typename OutputMeshType::PointIdentifier;
  using OutputCellIdentifier = typename OutputMeshType::CellIdentifier;
  using OutputCellAutoPointer = typename OutputMeshType::CellAutoPointer;
  using OutputCellType = typename OutputMeshType::CellType;
  using SizeValueType = typename MeshIOBase::SizeValueType;

  using OutputVertexCellType = VertexCell<OutputCellType>;
  using OutputLineCellType = LineCell<OutputCellType>;
  using OutputPolyLineCellType = PolyLineCell<OutputCellType>;
  using OutputTriangleCellType = TriangleCell<OutputCellType>;
  using OutputPolygonCellType = PolygonCell<OutputCellType>;
  using OutputTetrahedronCellType = TetrahedronCell<OutputCellType>;
  using OutputHexahedronCellType = HexahedronCell<OutputCellType>;
  using OutputQuadrilateralCellType = QuadrilateralCell<OutputCellType>;
  using OutputQuadraticEdgeCellType = QuadraticEdgeCell<OutputCellType>;
  using OutputQuadraticTriangleCellType = QuadraticTriangleCell<OutputCellType>;

  /** Define output point dimension */
  static constexpr unsigned int OutputPointDimension = OutputMeshType::PointDimension;

  /** Specify the file to read. This is forwarded to the IO instance. */
  itkSetStringMacro(FileName);
  itkGetStringMacro(FileName);

  /** Set/Get the MeshIO helper class. Often this is created via the object
   * factory mechanism that determines whether a particular MeshIO can
   * read a certain file. This method provides a way to get the MeshIO
   * instance that is created. Or you can directly specify the MeshIO
   * to use to read a particular file in case the factory mechanism will
   * not work properly (e.g., unknown or unusual extension). */
  void
  SetMeshIO(MeshIOBase * meshIO);
  itkGetModifiableObjectMacro(MeshIO, MeshIOBase);

  /** Prepare the allocation of the output mesh during the first back
   * propagation of the pipeline. */
  void
  GenerateOutputInformation() override;

  template <typename T>
  void
  ReadPoints(T * buffer);

  template <typename T>
  void
  ReadCells(T * buffer);

  void
  ReadPointData();

  void
  ReadCellData();

protected:
  MeshFileReader();
  ~MeshFileReader() override = default;
  void
  PrintSelf(std::ostream & os, Indent indent) const override;

  /** Convert a block of pixels from one type to another. */
  template <typename T>
  void
  ConvertPointPixelBuffer(void * inputData, T * outputData, size_t numberOfPixels);

  template <typename T>
  void
  ConvertCellPixelBuffer(void * inputData, T * outputData, size_t numberOfPixels);

  /** Test whether the given filename exist and it is readable, this
   * is intended to be called before attempting to use  MeshIO
   * classes for actually reading the file. If the file doesn't exist
   * or it is not readable, and exception with an appropriate message
   * will be thrown. */
  void
  TestFileExistanceAndReadability();

  /** Does the real work. */
  void
  GenerateData() override;

  MeshIOBase::Pointer m_MeshIO{};
  bool                m_UserSpecifiedMeshIO{}; // keep track whether the MeshIO is
                                               // user specified
  std::string m_FileName{};                    // The file to be read

private:
  template <typename T>
  void
  ReadPointsUsingMeshIO();

  template <typename T>
  void
  ReadCellsUsingMeshIO();

  std::string m_ExceptionMessage{};
};


/** Convenience function for reading a mesh.
 *
 * `TOutputMesh` is the expected output mesh type, and the optional
 * `ConvertPointPixelTraits`, ``ConvertCellPixelTraits` template parameters are used to do the conversion,
 * as specified by MeshFileReader.
 *
 * The function reads the mesh from the specified file, and returns the
 * mesh that it has read.
 * */
template <typename TOutputMesh,
          typename ConvertPointPixelTraits = MeshConvertPixelTraits<typename TOutputMesh::PixelType>,
          typename ConvertCellPixelTraits = MeshConvertPixelTraits<typename TOutputMesh::CellPixelType>>
typename TOutputMesh::Pointer
ReadMesh(const std::string & filename)
{
  const auto reader = MeshFileReader<TOutputMesh, ConvertPointPixelTraits, ConvertCellPixelTraits>::New();
  reader->SetFileName(filename);
  reader->Update();
  return reader->GetOutput();
}

} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkMeshFileReader.hxx"
#endif

#if defined ITK_MESHIO_FACTORY_REGISTER_MANAGER || defined ITK_IO_FACTORY_REGISTER_MANAGER
#  include "itkMeshIOFactoryRegisterManager.h"
#endif

#endif