/*
 * 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 otbGreyLevelCooccurrenceIndexedList_hxx
#define otbGreyLevelCooccurrenceIndexedList_hxx

#include "otbGreyLevelCooccurrenceIndexedList.h"

namespace otb
{
template <class TPixel>
GreyLevelCooccurrenceIndexedList<TPixel>::GreyLevelCooccurrenceIndexedList()
  : m_Size(), m_Symmetry(true), m_TotalFrequency(0), m_ClipBinsAtEnds(true), m_InputImageMinimum(0), m_InputImageMaximum(255)
{
}

template <class TPixel>
void GreyLevelCooccurrenceIndexedList<TPixel>::Initialize(const unsigned int nbins, const PixelValueType min, const PixelValueType max, const bool symmetry)
{
  PixelPairType lowerBound;
  PixelPairType upperBound;

  m_Size.Fill(nbins);
  m_InputImageMinimum = min;
  m_InputImageMaximum = max;
  lowerBound.Fill(min);
  upperBound.Fill(max + 1);

  m_Symmetry    = symmetry;
  m_LookupArray = LookupArrayType(m_Size[0] * m_Size[1]);
  m_LookupArray.Fill(-1);
  m_TotalFrequency = 0;

  // adjust the sizes of min max value containers
  unsigned int dim;
  m_Min.resize(PixelPairSize);
  for (dim = 0; dim < PixelPairSize; dim++)
  {
    m_Min[dim].resize(m_Size[dim]);
  }

  m_Max.resize(PixelPairSize);
  for (dim = 0; dim < PixelPairSize; dim++)
  {
    m_Max[dim].resize(m_Size[dim]);
  }

  float interval;
  for (unsigned int i = 0; i < PixelPairSize; i++)
  {
    if (m_Size[i] > 0)
    {
      interval = static_cast<float>(upperBound[i] - lowerBound[i]) / static_cast<PixelValueType>(m_Size[i]);

      // Set the min vector and max vector
      for (unsigned int j = 0; j < static_cast<unsigned int>(m_Size[i] - 1); j++)
      {
        this->SetBinMin(i, j, (PixelValueType)(lowerBound[i] + ((float)j * interval)));
        this->SetBinMax(i, j, (PixelValueType)(lowerBound[i] + (((float)j + 1) * interval)));
      }
      this->SetBinMin(i, m_Size[i] - 1, (PixelValueType)(lowerBound[i] + (((float)m_Size[i] - 1) * interval)));
      this->SetBinMax(i, m_Size[i] - 1, (PixelValueType)(upperBound[i]));
    }
  }
}

template <class TPixel>
void GreyLevelCooccurrenceIndexedList<TPixel>::SetBinMin(const unsigned int dimension, const InstanceIdentifier nbin, PixelValueType min)
{
  m_Min[dimension][nbin] = min;
}

template <class TPixel>
void GreyLevelCooccurrenceIndexedList<TPixel>::SetBinMax(const unsigned int dimension, const InstanceIdentifier nbin, PixelValueType max)
{
  m_Max[dimension][nbin] = max;
}

template <class TPixel>
bool GreyLevelCooccurrenceIndexedList<TPixel>::GetIndex(const PixelPairType& pixelPair, IndexType& index) const
{
  // now using something similar to binary search to find
  // index.
  unsigned int dim;

  int begin;
  int mid;
  int end;

  PixelValueType median;
  PixelValueType tempPixelValue;

  for (dim = 0; dim < PixelPairSize; dim++)
  {
    tempPixelValue = pixelPair[dim];
    begin          = 0;

    if (tempPixelValue < m_Min[dim][begin])
    {
      // one of measurement is below the minimum
      // its ok if we extend the bins to infinity.. not ok if we don't
      if (!m_ClipBinsAtEnds)
      {
        index[dim] = (IndexValueType)0;
        continue;
      }
      else
      { // set an illegal value and return 0
        index[dim] = (IndexValueType)m_Size[dim];
        return false;
      }
    }

    end = m_Min[dim].size() - 1;
    if (tempPixelValue >= m_Max[dim][end])
    {
      // one of measurement is above the maximum
      // its ok if we extend the bins to infinity.. not ok if we don't
      // Need to include the last endpoint in the last bin.
      if (!m_ClipBinsAtEnds || tempPixelValue == m_Max[dim][end])
      {
        index[dim] = (IndexValueType)m_Size[dim] - 1;
        continue;
      }
      else
      { // set an illegal value and return 0
        index[dim] = (IndexValueType)m_Size[dim];
        return false;
      }
    }

    // Binary search for the bin where this measurement could be
    mid    = (end + 1) / 2;
    median = m_Min[dim][mid];

    while (true)
    {
      if (tempPixelValue < median)
      {
        end = mid - 1;
      }
      else if (tempPixelValue > median)
      {
        // test whether it is inside the current bin by comparing to the max of
        // this bin.
        if (tempPixelValue < m_Max[dim][mid] && tempPixelValue >= m_Min[dim][mid])
        {
          index[dim] = mid;
          break;
        }
        // otherwise, continue binary search
        begin = mid + 1;
      }
      else
      {
        index[dim] = mid;
        break;
      }
      mid    = begin + (end - begin) / 2;
      median = m_Min[dim][mid];
    } // end of while
  }   // end of for()
  return true;
}

template <class TPixel>
void GreyLevelCooccurrenceIndexedList<TPixel>::AddPixelPair(const PixelValueType& pixelvalue1, const PixelValueType& pixelvalue2)
{

  if (pixelvalue1 < m_InputImageMinimum || pixelvalue1 > m_InputImageMaximum)
  {
    return; // don't put a pixel in the co-occurrence list if pixelvalue1
            // is out-of-bounds.
  }

  if (pixelvalue2 < m_InputImageMinimum || pixelvalue2 > m_InputImageMaximum)
  {
    return; // don't put a pixel in the co-occurrence list if the pixelvalue2
            // is out-of-bounds.
  }

  IndexType     index;
  PixelPairType ppair(PixelPairSize);
  ppair[0] = pixelvalue1;
  ppair[1] = pixelvalue2;

  // Get Index of the given pixel pair;
  this->GetIndex(ppair, index);
  // Add the index and set/update the frequency of the pixel pair. if m_Symmetry
  // is true the index is swapped and added to vector again.
  this->AddPairToVector(index);
  if (m_Symmetry)
  {
    IndexValueType temp;
    temp     = index[0];
    index[0] = index[1];
    index[1] = temp;
    this->AddPairToVector(index);
  }
}

template <class TPixel>
typename GreyLevelCooccurrenceIndexedList<TPixel>::RelativeFrequencyType GreyLevelCooccurrenceIndexedList<TPixel>::GetFrequency(IndexValueType i,
                                                                                                                                IndexValueType j)
{
  double             frequency  = 0;
  InstanceIdentifier instanceId = i * m_Size[0] + j;
  if (instanceId < m_LookupArray.size())
  {
    int findex = m_LookupArray[instanceId];
    if (findex > -1)
      frequency = m_Vector[findex].second / m_TotalFrequency;
  }
  return frequency;
}

template <class TPixel>
typename GreyLevelCooccurrenceIndexedList<TPixel>::RelativeFrequencyType
GreyLevelCooccurrenceIndexedList<TPixel>::GetFrequency(IndexValueType i, IndexValueType j, const VectorType& vect) const
{
  double             frequency  = 0;
  InstanceIdentifier instanceId = i * m_Size[0] + j;
  if (instanceId < m_LookupArray.size())
  {
    int findex = m_LookupArray[instanceId];
    if (findex > -1)
      frequency = vect[findex].second;
  }
  return frequency;
}

template <class TPixel>
typename GreyLevelCooccurrenceIndexedList<TPixel>::VectorType GreyLevelCooccurrenceIndexedList<TPixel>::GetVector()
{
  return m_Vector;
}

template <class TPixel>
void GreyLevelCooccurrenceIndexedList<TPixel>::AddPairToVector(IndexType index)
{
  InstanceIdentifier instanceId = 0;
  instanceId                    = index[1] * m_Size[0] + index[0];
  int vindex                    = m_LookupArray[instanceId];
  if (vindex < 0)
  {
    m_LookupArray[instanceId] = m_Vector.size();

    CooccurrencePairType cooccur;
    cooccur = std::make_pair(index, 1);
    m_Vector.push_back(cooccur);
  }
  else
  {
    m_Vector[vindex].second++;
  }
  m_TotalFrequency = m_TotalFrequency + 1;
}

template <class TPixel>
void GreyLevelCooccurrenceIndexedList<TPixel>::PrintSelf(std::ostream& os, itk::Indent indent) const
{
  Superclass::PrintSelf(os, indent);
  os << indent << "Symmetry: " << this->m_Symmetry << std::endl;
  os << indent << "TotalFrequency: " << this->m_TotalFrequency << std::endl;
  os << indent << "Size: " << m_Size;
  os << indent << "CooccurrenceIndexedList: " << std::endl;
  typename VectorType::const_iterator it;
  for (it = m_Vector.begin(); it != m_Vector.end(); ++it)
  {
    std::cerr << "index=" << (*it).first << ", frequency=" << (*it).second << std::endl;
  }
  std::cerr << std::endl;
}

} // end namespace otb

#endif
