/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  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
 *
 *         http://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 itkLineCell_h
#define itkLineCell_h

#include "itkVertexCell.h"

namespace itk
{
/** \class LineCell
 *  \brief Represents a line segment for a Mesh.
 *
 * LineCell represents a line segment for a Mesh.
 *
 * Template parameters for LineCell:
 *
 * \tparam TPixelType The type associated with a point, cell, or boundary
 * for use in storing its data.
 *
 * \tparam TCellTraits Type information of mesh containing cell.
 *
 * \ingroup MeshObjects
 * \ingroup ITKCommon
 */

template< typename TCellInterface >
class ITK_TEMPLATE_EXPORT LineCell:public TCellInterface
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(LineCell);

  /** Standard class type aliases. */
  itkCellCommonTypedefs(LineCell);
  itkCellInheritedTypedefs(TCellInterface);

  /** Standard part of every itk Object. */
  itkTypeMacro(LineCell, CellInterface);

  /** The type of boundary for this lines's vertices. */
  using VertexType = VertexCell< TCellInterface >;
  using VertexAutoPointer = typename VertexType::SelfAutoPointer;

  /** Line-specific topology numbers. */
  static constexpr unsigned int NumberOfPoints = 2;
  static constexpr unsigned int NumberOfVertices = 2;
  static constexpr unsigned int CellDimension = 1;

  /** Implement the standard CellInterface. */
  CellGeometry GetType() const override
  { return Superclass::LINE_CELL; }
  void MakeCopy(CellAutoPointer &) const override;

  unsigned int GetDimension() const override;

  unsigned int GetNumberOfPoints() const override;

  CellFeatureCount GetNumberOfBoundaryFeatures(int dimension) const override;

  bool GetBoundaryFeature(int dimension, CellFeatureIdentifier, CellAutoPointer &) override;
  void SetPointIds(PointIdConstIterator first) override;

  void SetPointIds(PointIdConstIterator first,
                           PointIdConstIterator last) override;

  void SetPointId(int localId, PointIdentifier) override;
  PointIdIterator      PointIdsBegin() override;

  PointIdConstIterator PointIdsBegin() const override;

  PointIdIterator      PointIdsEnd() override;

  PointIdConstIterator PointIdsEnd() const override;

  /** Line-specific interface. */
  virtual CellFeatureCount GetNumberOfVertices() const;

  virtual bool GetVertex(CellFeatureIdentifier, VertexAutoPointer &);

  /** Visitor interface */
  itkCellVisitMacro(Superclass::LINE_CELL);

  LineCell()
  {
    for ( unsigned int i = 0; i < Self::NumberOfPoints; i++ )
      {
      m_PointIds[i] = NumericTraits< PointIdentifier >::max();
      }
  }

  ~LineCell() override = default;

protected:
  /** Store number of points needed for a line segment. */
  PointIdentifier m_PointIds[NumberOfPoints];
};
} // end namespace itk

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

#endif
