/*=========================================================================
 *
 *  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 itkFEMLightObject_h
#define itkFEMLightObject_h

#include "itkMacro.h"
#include "itkSmartPointer.h"
#include "itkObjectFactory.h"
#include "itkLightObject.h"
#include "ITKFEMExport.h"

#include "itkFEMException.h"
#include <iostream>

namespace itk
{
namespace fem
{
/**
 * \class FEMLightObject
 * \brief Base class for all classes that define the FEM system.
 *
 * Base class for all classes that define FEM system (Elements, Nodes...).
 * Every FEM object requires a global number that can be used to find
 * that object. It is also required that the object can be written to and
 * read from a file (stream). This functionality is implemented inside
 * FEMLightObject class.
 * \ingroup ITKFEM
 */
class ITKFEM_EXPORT FEMLightObject : public itk::LightObject
{
public:
  /** Standard class type aliases. */
  using Self = FEMLightObject;
  using Superclass = itk::LightObject;
  using Baseclass = Self;
  using Pointer = SmartPointer<Self>;
  using ConstPointer = SmartPointer<const Self>;

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

  /**
   * Set the global number of the object
   */
  void
  SetGlobalNumber(int);

  /**
   * Get the global number of the object
   */
  int
  GetGlobalNumber() const;

protected:
  /**
   * Default constructor
   */
  FEMLightObject() = default;

  /**
   * Virtual destructor
   */
  ~FEMLightObject() override = default;

  void
  PrintSelf(std::ostream & os, Indent indent) const override;

  /**
   * Copy constructor must be available for the FEM objects...
   */
  FEMLightObject(const FEMLightObject & o)
    : itk::LightObject()
  {
    m_GlobalNumber = o.m_GlobalNumber;
  }

  /**
   * Global number of an object (ID of an object)
   * In general the ID's are required to be unique only within
   * a specific type of derived classes (Elements, Nodes, ...)
   * If the GN is not required, it can be ignored. (normally you
   * need the GN when writing or reading objects to/from stream.
   */
  int m_GlobalNumber{ -1 };
};
} // end namespace fem
} // end namespace itk

#endif // itkFEMLightObject_h