/*
 * 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 otbMultiChannelsPolarimetricSynthesisFilter_h
#define otbMultiChannelsPolarimetricSynthesisFilter_h

#include "itkInPlaceImageFilter.h"
#include "otbPolarimetricSynthesisFunctor.h"
#include "otbPolarimetricData.h"
#include <complex>

namespace otb
{

/** \class MultiChannelsPolarimetricSynthesisFilter
 * \brief This class computes the polarimetric synthesis from two to four radar images, depening on the polarimetric architecture.
 *
 * It has the same behaviour as the PolarimetricSynthesisImageFilter expect the fact that it
 * considers a VectorImage as input which each channels is HH, HV, VH and VV (in this particular order).
 *
 * \ingroup SARPolarimetry
 * \sa PolarimetricSynthesisFilter
 * \sa PolarimetricSynthesisFunctor
 *
 *
 * \ingroup OTBPolarimetry
 */

template <class TInputImage, class TOutputImage,
          class TFunction = Functor::PolarimetricSynthesisFunctor<typename TInputImage::InternalPixelType, typename TInputImage::InternalPixelType,
                                                                  typename TInputImage::InternalPixelType, typename TInputImage::InternalPixelType,
                                                                  typename TOutputImage::PixelType>>
class ITK_EXPORT MultiChannelsPolarimetricSynthesisFilter : public itk::InPlaceImageFilter<TInputImage, TOutputImage>
{
public:
  /** Standard class typedefs. */
  typedef MultiChannelsPolarimetricSynthesisFilter Self;
  typedef itk::InPlaceImageFilter<TInputImage, TOutputImage> 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(MultiChannelsPolarimetricSynthesisFilter, InPlaceImageFilter);

  /** Some typedefs. */
  typedef std::complex<double>                  InputPixelType;
  typedef TFunction                             FunctorType;
  typedef TInputImage                           InputImageType;
  typedef typename InputImageType::ConstPointer InputImagePointer;
  typedef typename InputImageType::RegionType   InputImageRegionType;
  typedef typename InputImageType::PixelType    InputImagePixelType;
  typedef TOutputImage                          OutputImageType;
  typedef typename OutputImageType::Pointer     OutputImagePointer;
  typedef typename OutputImageType::RegionType  OutputImageRegionType;
  typedef typename OutputImageType::PixelType   OutputImagePixelType;
  typedef typename std::complex<double>         ComplexType;
  typedef typename itk::FixedArray<ComplexType, 2> ComplexArrayType;
  typedef typename itk::FixedArray<int, 4>         IndexArrayType;

  /** Get the functor object.  The functor is returned by reference.
   * (Functors do not have to derive from itk::LightObject, so they do
   * not necessarily have a reference count. So we cannot return a
   * SmartPointer.) */
  FunctorType& GetFunctor()
  {
    return m_Functor;
  }
  const FunctorType& GetFunctor() const
  {
    return m_Functor;
  }

  /** Set the functor object.  This replaces the current Functor with a
   * copy of the specified Functor. This allows the user to specify a
   * functor that has ivars set differently than the default functor.
   * This method requires an operator!=() be defined on the functor
   * (or the compiler's default implementation of operator!=() being
   * appropriate). */
  void SetFunctor(const FunctorType& functor)
  {
    if (m_Functor != functor)
    {
      m_Functor = functor;
      this->Modified();
    }
  }
  /** Set the Incident ElectroMagneticField */
  void SetEi(ComplexArrayType ei)
  {
    m_Ei = ei;
    this->GetFunctor().SetEi(ei);
    this->Modified();
  }
  /** Set the Reflected ElectroMagneticField */
  void SetEr(ComplexArrayType er)
  {
    m_Er = er;
    this->GetFunctor().SetEr(er);
    this->Modified();
  }

  /** Set/Get PsiI */
  itkSetMacro(PsiI, double);
  itkGetMacro(PsiI, double);
  /** Set/Get KhiI */
  itkSetMacro(KhiI, double);
  itkGetMacro(KhiI, double);
  /** Set/Get PsiR */
  itkSetMacro(PsiR, double);
  itkGetMacro(PsiR, double);
  /** Set/Get KhiR */
  itkSetMacro(KhiR, double);
  itkGetMacro(KhiR, double);
  /** Set/Get EmissionH */
  itkSetMacro(EmissionH, bool);
  itkGetMacro(EmissionH, bool);
  /** Set/Get EmissionV */
  itkSetMacro(EmissionV, bool);
  itkGetMacro(EmissionV, bool);
  /** Set/Get Mode */
  itkSetMacro(Mode, int);
  itkGetMacro(Mode, int);
  /** Set the gain */
  itkSetMacro(Gain, double);
  itkGetMacro(Gain, double);
  /** Force the copolar mode */
  void ForceCoPolar();
  /** Force the crosspolar mode */
  void ForceCrossPolar();

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

  /** MultiChannelsPolarimetricSynthesisFilter can produce an image
   * which is a synthesis of channels HH, HV, VH and VV.
   *
   * As such, MultiChannelsPolarimetricSynthesisFilter
   * needs to provide an implementation for
   * GenerateOutputInformation() in order to inform the pipeline
   * execution model.  The original documentation of this method is
   * below.
   *
   * \sa ProcessObject::GenerateOutputInformaton()  */
  void GenerateOutputInformation() override;

  void BeforeThreadedGenerateData() override;

  /** MultiChannelsPolarimetricSynthesisFilter can be implemented as a multithreaded filter.
   * Therefore, this implementation provides a ThreadedGenerateData() routine
   * which is called for each processing thread. The output image data is
   * allocated automatically by the superclass prior to calling
   * ThreadedGenerateData().  ThreadedGenerateData can only write to the
   * portion of the output image specified by the parameter
   * "outputRegionForThread"
   *
   * \sa ImageToImageFilter::ThreadedGenerateData(),
   *     ImageToImageFilter::GenerateData()  */
  void ThreadedGenerateData(const OutputImageRegionType& outputRegionForThread, itk::ThreadIdType threadId) override;

  /** Computation of the electromagnetic fields Ei Er */
  void ComputeElectromagneticFields();

  /** Verify and force the inputs, if only  2 or 3 channels are present */
  void VerifyAndForceInputs();

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

private:
  MultiChannelsPolarimetricSynthesisFilter(const Self&) = delete;

  /** Psi Incident */
  double m_PsiI;
  /** Khi Incident */
  double m_KhiI;
  /** Psi Reflected */
  double m_PsiR;
  /** Khi Reflected */
  double m_KhiR;

  /** Gain */
  double m_Gain;

  /** None = 0 , copolar = 1 , crosspolar = 2 */
  int m_Mode;

  /** Champs Electromagnetic Incident */
  ComplexArrayType m_Ei;
  /** Champs Electromagnetic Reflechi */
  ComplexArrayType m_Er;

  /** Architecture Type */
  PolarimetricData::Pointer m_ArchitectureType;

  FunctorType m_Functor;

  /** Emission mode */
  bool m_EmissionH;
  bool m_EmissionV;
};

} // end namespace otb

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

#endif
