/*
 * Copyright (C) 2005-2020 Centre National d'Etudes Spatiales (CNES)
 *
 * This file is part of Orfeo Toolbox
 *
 *     https://www.orfeo-toolbox.org/
 *
 * 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
 *
 * 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 otbPointSetSource_h
#define otbPointSetSource_h


#include "itkProcessObject.h"

namespace otb
{
/** \class PointSetSource
 *  \brief Base class for all process objects that output point set data.
 *
 * PointSetSource is the base class for all process objects that output
 * point set data. Specifically, this class defines the GetOutput() method
 * that returns a pointer to the output point set. The class also defines
 * some internal private data members that are used to manage streaming
 * of data.
 *
 * \ingroup DataSources
 *
 * \ingroup OTBPointSet
 */

template <class TOutputPointSet>
class ITK_EXPORT PointSetSource : public itk::ProcessObject
{
public:
  /** Standard class typedefs. */
  typedef PointSetSource                Self;
  typedef itk::ProcessObject            Superclass;
  typedef itk::SmartPointer<Self>       Pointer;
  typedef itk::SmartPointer<const Self> ConstPointer;

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

  /** Run-time type information (and related methods). */
  itkTypeMacro(PointSetSource, itk::ProcessObject);

  /** Some convenient typedefs. */
  typedef itk::ProcessObject::DataObjectPointerArraySizeType DataObjectPointerArraySizeType;
  typedef itk::DataObject::Pointer                           DataObjectPointer;
  typedef TOutputPointSet                                    OutputPointSetType;
  typedef typename OutputPointSetType::Pointer               OutputPointSetPointer;
  typedef typename OutputPointSetType::PointsContainer       PointsContainerType;
  typedef typename OutputPointSetType::PointDataContainer    PointDataContainerType;

  /** Get the point set output of this process object.  */
  OutputPointSetType* GetOutput(void);
  OutputPointSetType* GetOutput(DataObjectPointerArraySizeType idx);

  /** Set the point set output of this process object. This call is slated
   * to be removed from ITK. You should GraftOutput() and possible
   * DataObject::DisconnectPipeline() to properly change the output. */
  void SetOutput(OutputPointSetType* output);
  using Superclass::SetOutput;

  /** Graft the specified DataObject onto this ProcessObject's output.
   * This method grabs a handle to the specified DataObject's bulk
   * data to used as its output's own bulk data. It also copies the
   * region ivars (RequestedRegion, BufferedRegion,
   * LargestPossibleRegion) and meta-data (Spacing, Origin) from the
   * specified data object into this filter's output data object. Most
   * importantly, however, it leaves the Source ivar untouched so the
   * original pipeline routing is intact. This method is used when a
   * process object is implemented using a mini-pipeline which is
   * defined in its GenerateData() method.  The usage is:
   *
   * \code
   *    // setup the mini-pipeline to process the input to this filter
   *    firstFilterInMiniPipeline->SetInput( this->GetInput() );
   *
   *    // setup the mini-pipeline to calculate the correct regions
   *    // and write to the appropriate bulk data block
   *    lastFilterInMiniPipeline->GraftOutput( this->GetOutput() );
   *
   *    // execute the mini-pipeline
   *    lastFilterInMiniPipeline->Update();
   *
   *    // graft the mini-pipeline output back onto this filter's output.
   *    // this is needed to get the appropriate regions passed back.
   *    this->GraftOutput( lastFilterInMiniPipeline->GetOutput() );
   * \endcode
   *
   * For proper pipeline execution, a filter using a mini-pipeline
   * must implement the GenerateInputRequestedRegion(),
   * GenerateOutputRequestedRegion(), GenerateOutputInformation() and
   * EnlargeOutputRequestedRegion() methods as necessary to reflect
   * how the mini-pipeline will execute (in other words, the outer
   * filter's pipeline mechanism must be consistent with what the
   * mini-pipeline will do). */
  virtual void GraftOutput(itk::DataObject* output);
  virtual void GraftNthOutput(DataObjectPointerArraySizeType idx, itk::DataObject* output);

  /** Make a DataObject of the correct type to used as the specified
   * output.  Every ProcessObject subclass must be able to create a
   * DataObject that can be used as a specified output. This method
   * is automatically called when DataObject::DisconnectPipeline() is
   * called.  DataObject::DisconnectPipeline, disconnects a data object
   * from being an output of its current source.  When the data object
   * is disconnected, the ProcessObject needs to construct a replacement
   * output data object so that the ProcessObject is in a valid state.
   * So DataObject::DisconnectPipeline eventually calls
   * ProcessObject::MakeOutput. Note that MakeOutput always returns a
   * SmartPointer to a DataObject. If a subclass of MeshSource has
   * multiple outputs of different types, then that class must provide
   * an implementation of MakeOutput(). */
  DataObjectPointer MakeOutput(DataObjectPointerArraySizeType idx) override;
  using Superclass::MakeOutput;

protected:
  PointSetSource();
  ~PointSetSource() override
  {
  }
  void PrintSelf(std::ostream& os, itk::Indent indent) const override;

  /** Requested region of Point Set is specified as i of N unstructured regions.
   * Since all DataObjects should be able to set the requested region in
   * unstructured form, just copy output->RequestedRegion all inputs. */
  void GenerateInputRequestedRegion() override;

private:
  PointSetSource(const Self&) = delete;
  void operator=(const Self&) = delete;

  /** Used by streaming: The requested region of the output being processed
   * by the execute method. Set in the GenerateInputRequestedRegion method. */
  int m_GenerateDataRegion;
  int m_GenerateDataNumberOfRegions;
};

} // end namespace otb

#ifndef OTB_MANUAL_INSTANTIATION
#include "otbPointSetSource.hxx"
#endif

#endif
