/*
 * Copyright (C) 1999-2011 Insight Software Consortium
 * 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 otbStreamingCompareImageFilter_h
#define otbStreamingCompareImageFilter_h

#include "otbPersistentImageFilter.h"
#include "itkNumericTraits.h"
#include "itkArray.h"
#include "itkSimpleDataObjectDecorator.h"
#include "otbPersistentFilterStreamingDecorator.h"

namespace otb
{

/** \class PersistentCompareImageFilter
 * \brief Compute mean squared error,  mean absolute error and PSNR of two imagee using the output requested region.
 *
 *  This filter persists its temporary data. It means that if you Update it n times on n different
 * requested regions, the output estimators will be the estimators of the whole set of n regions.
 *
 * To reset the temporary data, one should call the Reset() function.
 *
 * To get the estimators once the regions have been processed via the pipeline, use the Synthetize() method.
 *
 * \sa PersistentImageFilter
 * \ingroup Streamed
 * \ingroup Multithreaded
 *
 * \ingroup OTBStatistics
 */
template <class TInputImage>
class ITK_EXPORT PersistentCompareImageFilter : public PersistentImageFilter<TInputImage, TInputImage>
{
public:
  /** Standard Self typedef */
  typedef PersistentCompareImageFilter Self;
  typedef PersistentImageFilter<TInputImage, TInputImage> Superclass;
  typedef itk::SmartPointer<Self>       Pointer;
  typedef itk::SmartPointer<const Self> ConstPointer;

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

  /** Runtime information support. */
  itkTypeMacro(PersistentCompareImageFilter, PersistentImageFilter);

  /** Image related typedefs. */
  typedef TInputImage                   ImageType;
  typedef typename TInputImage::Pointer InputImagePointer;

  typedef typename TInputImage::RegionType                   RegionType;
  typedef typename TInputImage::SizeType                     SizeType;
  typedef typename TInputImage::IndexType                    IndexType;
  typedef typename TInputImage::PixelType                    PixelType;
  typedef itk::ProcessObject::DataObjectPointerArraySizeType DataObjectPointerArraySizeType;

  itkStaticConstMacro(InputImageDimension, unsigned int, TInputImage::ImageDimension);

  /** Image related typedefs. */
  itkStaticConstMacro(ImageDimension, unsigned int, TInputImage::ImageDimension);

  /** Type to use for computations. */
  typedef typename itk::NumericTraits<PixelType>::RealType RealType;

  /** Smart Pointer type to a DataObject. */
  typedef typename itk::DataObject::Pointer DataObjectPointer;

  /** Type of DataObjects used for scalar outputs */
  typedef itk::SimpleDataObjectDecorator<RealType>  RealObjectType;
  typedef itk::SimpleDataObjectDecorator<PixelType> PixelObjectType;

  /** Get the inputs */
  const TInputImage* GetInput1();
  const TInputImage* GetInput2();

  /** Connect one the first operands. */
  void SetInput1(const TInputImage* image);

  /** Connect one the second operands. */
  void SetInput2(const TInputImage* image);

  /** Return the computed PSNR. */
  RealType GetPSNR() const
  {
    return this->GetPSNROutput()->Get();
  }
  RealObjectType*       GetPSNROutput();
  const RealObjectType* GetPSNROutput() const;

  /** Return the computed MSE. */
  RealType GetMSE() const
  {
    return this->GetMSEOutput()->Get();
  }
  RealObjectType*       GetMSEOutput();
  const RealObjectType* GetMSEOutput() const;

  /** Return the computed MAE. */
  RealType GetMAE() const
  {
    return this->GetMAEOutput()->Get();
  }
  RealObjectType*       GetMAEOutput();
  const RealObjectType* GetMAEOutput() const;

  /** Return the Number of Pixel which are different. */
  RealType GetDiffCount() const
  {
    return this->GetDiffCountOutput()->Get();
  }
  RealObjectType*       GetDiffCountOutput();
  const RealObjectType* GetDiffCountOutput() const;

  itkGetMacro(PhysicalSpaceCheck, bool);
  itkSetMacro(PhysicalSpaceCheck, bool);

  /** Make a DataObject of the correct type to be used as the specified
   * output. */
  DataObjectPointer MakeOutput(DataObjectPointerArraySizeType idx) override;
  using Superclass::MakeOutput;

  /** Pass the input through unmodified. Do this by Grafting in the
   *  AllocateOutputs method.
   */
  void AllocateOutputs() override;
  void GenerateOutputInformation() override;
  void Synthetize(void) override;
  void Reset(void) override;

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

  /** Multi-thread version GenerateData. */
  void ThreadedGenerateData(const RegionType& outputRegionForThread, itk::ThreadIdType threadId) override;

  /** Allows skipping the verification of physical space between
   *  the two input images (see flag m_PhysicalSpaceCheck)
   */
  void VerifyInputInformation() override;

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

  itk::Array<RealType>  m_SquareOfDifferences;
  itk::Array<RealType>  m_AbsoluteValueOfDifferences;
  itk::Array<PixelType> m_ThreadMinRef;
  itk::Array<PixelType> m_ThreadMaxRef;
  itk::Array<long>      m_Count;
  itk::Array<long>      m_DiffCount;
  bool                  m_PhysicalSpaceCheck;
}; // end of class PersistentCompareImageFilter

/*===========================================================================*/

/** \class StreamingCompareImageFilter
 * \brief This class streams the whole input image through the PersistentCompareImageFilter.
 *
 * This way, it allows computing estimator on two images. It calls the
 * Reset() method of the PersistentCompareImageFilter before streaming the image and the
 * Synthetize() method of the PersistentCompareImageFilter after having streamed the image
 * to compute the estimators. The accessor on the results are wrapping the accessors of the
 * internal PersistentCompareImageFilter.
 *
 * This filter can be used as:
 * \code
 * typedef otb::StreamingCompareImageFilter<ImageType> CompareType;
 * CompareType::Pointer estimators = CompareType::New();
 * estimators->SetInput(reader->GetOutput());
 * estimators->Update();
 * std::cout << estimators-> GetMSE() << std::endl;
 * std::cout << estimators-> GetPSNR() << std::endl;
 * \endcode
 *
 * \sa PersistentCompareImageFilter
 * \sa PersistentImageFilter
 * \sa PersistentFilterStreamingDecorator
 * \sa StreamingImageVirtualWriter
 * \ingroup Streamed
 * \ingroup Multithreaded
 *
 * \ingroup OTBStatistics
 */

template <class TInputImage>
class ITK_EXPORT StreamingCompareImageFilter : public PersistentFilterStreamingDecorator<PersistentCompareImageFilter<TInputImage>>
{
public:
  /** Standard Self typedef */
  typedef StreamingCompareImageFilter                                                   Self;
  typedef PersistentFilterStreamingDecorator<PersistentCompareImageFilter<TInputImage>> Superclass;
  typedef itk::SmartPointer<Self>                                                       Pointer;
  typedef itk::SmartPointer<const Self>                                                 ConstPointer;

  /** Type macro */
  itkNewMacro(Self);

  /** Creation through object factory macro */
  itkTypeMacro(StreamingCompareImageFilter, PersistentFilterStreamingDecorator);

  typedef typename Superclass::FilterType       CompareFilterType;
  typedef typename CompareFilterType::PixelType PixelType;
  typedef typename CompareFilterType::RealType  RealType;
  typedef TInputImage                           InputImageType;

  /** Type of DataObjects used for scalar outputs */
  typedef itk::SimpleDataObjectDecorator<RealType>  RealObjectType;
  typedef itk::SimpleDataObjectDecorator<PixelType> PixelObjectType;

  /** Connect one the first operands. */
  void SetInput1(InputImageType* input)
  {
    this->GetFilter()->SetInput1(input);
  }

  /** Connect one the second operands. */
  void SetInput2(InputImageType* input)
  {
    this->GetFilter()->SetInput2(input);
  }

  /** Return the computed PSNR. */
  RealType GetPSNR() const
  {
    return this->GetFilter()->GetPSNROutput()->Get();
  }
  RealObjectType* GetPSNROutput()
  {
    return this->GetFilter()->GetPSNROutput();
  }
  const RealObjectType* GetPSNROutput() const
  {
    return this->GetFilter()->GetPSNROutput();
  }

  /** Return the computed MSE. */
  RealType GetMSE() const
  {
    return this->GetMSEOutput()->Get();
  }
  RealObjectType* GetMSEOutput()
  {
    return this->GetFilter()->GetMSEOutput();
  }
  const RealObjectType* GetMSEOutput() const
  {
    return this->GetFilter()->GetMSEOutput();
  }

  /** Return the computed MAE. */
  RealType GetMAE() const
  {
    return this->GetFilter()->GetMAEOutput()->Get();
  }
  RealObjectType* GetMAEOutput()
  {
    return this->GetFilter()->GetMAEOutput();
  }
  const RealObjectType* GetMAEOutput() const
  {
    return this->GetFilter()->GetMAEOutput();
  }

  /** Return the Number of Pixel different. */
  RealType GetDiffCount() const
  {
    return this->GetFilter()->GetDiffCountOutput()->Get();
  }
  RealObjectType* GetDiffCountOutput()
  {
    return this->GetFilter()->GetDiffCountOutput();
  }
  const RealObjectType* GetDiffCountOutput() const
  {
    return this->GetFilter()->GetDiffCountOutput();
  }

  /** Set the PhysicalSpaceCheck flag */
  void SetPhysicalSpaceCheck(bool flag)
  {
    this->GetFilter()->SetPhysicalSpaceCheck(flag);
  }

  /** Get the PhysicalSpaceCheck flag */
  bool GetPhysicalSpaceCheck()
  {
    return this->GetFilter()->GetPhysicalSpaceCheck();
  }

protected:
  /** Constructor */
  StreamingCompareImageFilter(){};
  /** Destructor */
  ~StreamingCompareImageFilter() override
  {
  }

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

} // end namespace otb

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

#endif
