/*
 * 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 otbPathListSource_h
#define otbPathListSource_h

// #include "itkProcessObject.h"
// #include "itkDataObject.h"
#include "otbObjectListSource.h"

namespace otb
{

/** \class PathListSource
 * \brief Base class for filters with a PathList output type.
 *
 * PathListSource is the base class for all filters producing a PathList.
 * This class defines the GetOutput().
 *
 * \ingroup DataSources
 * \ingroup Paths
 * \ingroup Lists
 *
 * \ingroup OTBPath
 */

template <class TOutputPath>
class ITK_EXPORT PathListSource : public ObjectListSource<ObjectList<TOutputPath>>
{
public:
  /** Standard class typedefs. */
  typedef PathListSource                            Self;
  typedef ObjectListSource<ObjectList<TOutputPath>> 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(PathListSource, ObjectListSource);

  /** Some convenient typedefs. */
  typedef itk::DataObject::Pointer                           DataObjectPointer;
  typedef itk::ProcessObject::DataObjectPointerArraySizeType DataObjectPointerArraySizeType;

  typedef TOutputPath                               OutputPathType;
  typedef typename OutputPathType::Pointer          OutputPathPointerType;
  typedef typename Superclass::OutputListType       OutputPathListType;
  typedef typename OutputPathListType::Pointer      OutputPathListPointerType;
  typedef typename OutputPathListType::ConstPointer OutputPathListConstPointerType;

  /** Get the output data of this process object.  The output of this
   * function is not valid until an appropriate Update() method has
   * been called, either explicitly or implicitly.  Both the filter
   * itself and the data object have Update() methods, and both
   * methods update the data.  Here are three ways to use
   * GetOutput() and make sure the data is valid.  In these
   * examples, \a image is a pointer to some Image object, and the
   * particular ProcessObjects involved are filters.  The same
   * examples apply to non-image (e.g. Mesh) data as well.
   *
   * \code
   *   anotherFilter->SetInput( someFilter->GetOutput() );
   *   anotherFilter->Update();
   * \endcode
   *
   * In this situation, \a someFilter and \a anotherFilter are said
   * to constitute a \b pipeline.
   *
   * \code
   *   image = someFilter->GetOutput();
   *   image->Update();
   * \endcode
   *
   * \code
   *   someFilter->Update();
   *   image = someFilter->GetOutput();
   * \endcode
   * (In the above example, the two lines of code can be in
   * either order.)
   *
   * Note that Update() is not called automatically except within a
   * pipeline as in the first example.  When \b streaming (using a
   * StreamingImageFilter) is activated, it may be more efficient to
   * use a pipeline than to call Update() once for each filter in
   * turn.
   *
   * For an image, the data generated is for the requested
   * Region, which can be set using ImageBase::SetRequestedRegion().
   * By default, the largest possible region is requested.
   */
  //   OutputPathListType * GetOutput(void);
  //   OutputPathListType * GetOutput(DataObjectPointerArraySizeType idx);

  /** Graft the specified DataObject onto this ProcessObject's output.
   * This method grabs a handle to the specified DataObject's path
   * data to use as its output's own path 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 GeneratseInputRequestedRegion(),
   * 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). */
  // just calls GraftNthOutput()
  //   virtual void GraftOutput(OutputPathListType *output);

  /** Graft the specified data object onto this ProcessObject's idx'th
   * output. This is the similar to GraftOutput method except is
   * allows you specify which output is affected. The specified index
   * must be a valid output number (less than
   * ProcessObject::GetNumberOfOutputs()). See the GraftOutput for
   * general usage information. */
  //   virtual void GraftNthOutput(DataObjectPointerArraySizeType idx, OutputPathListType *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 ImageSource has
   * multiple outputs of different types, then that class must provide
   * an implementation of MakeOutput(). */
  //   virtual DataObjectPointer MakeOutput(DataObjectPointerArraySizeType idx);

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

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

} // end namespace otb

// #ifndef OTB_MANUAL_INSTANTIATION
// #include "otbPathListSource.hxx"
// #endif

#endif
