/*
 * 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 otbSharkKMeansMachineLearningModel_hxx
#define otbSharkKMeansMachineLearningModel_hxx

#include <fstream>
#include "boost/make_shared.hpp"
#include "itkMacro.h"
#include "otbSharkKMeansMachineLearningModel.h"

#if defined(__GNUC__) || defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wshadow"
#pragma GCC diagnostic ignored "-Wunused-parameter"
#pragma GCC diagnostic ignored "-Woverloaded-virtual"
#pragma GCC diagnostic ignored "-Wignored-qualifiers"
#endif

#include "otb_shark.h"
#include "otbSharkUtils.h"
#include "shark/Algorithms/KMeans.h" //k-means algorithm
#include "shark/Models/Clustering/HardClusteringModel.h"
#include "shark/Models/Clustering/SoftClusteringModel.h"
#include <shark/Data/Csv.h> //load the csv file

#if defined(__GNUC__) || defined(__clang__)
#pragma GCC diagnostic pop
#endif


namespace otb
{
template <class TInputValue, class TOutputValue>
SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::SharkKMeansMachineLearningModel() : m_K(2), m_MaximumNumberOfIterations(10)
{
  // Default set HardClusteringModel
  this->m_ConfidenceIndex = true;
  m_ClusteringModel       = boost::make_shared<ClusteringModelType>(&m_Centroids);
}


template <class TInputValue, class TOutputValue>
SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::~SharkKMeansMachineLearningModel()
{
}

/** Train the machine learning model */
template <class TInputValue, class TOutputValue>
void SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::Train()
{
  // Parse input data and convert to Shark Data
  std::vector<shark::RealVector> vector_data;
  otb::Shark::ListSampleToSharkVector(this->GetInputListSample(), vector_data);
  shark::Data<shark::RealVector> data = shark::createDataFromRange(vector_data);

  // Use a Hard Clustering Model for classification
  shark::kMeans(data, m_K, m_Centroids, m_MaximumNumberOfIterations);
  m_ClusteringModel = boost::make_shared<ClusteringModelType>(&m_Centroids);
}

template <class TInputValue, class TOutputValue>
typename SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::TargetSampleType
SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::DoPredict(const InputSampleType& value, ConfidenceValueType* quality, ProbaSampleType* proba) const
{
  shark::RealVector data(value.Size());
  for (size_t i = 0; i < value.Size(); i++)
  {
    data.push_back(value[i]);
  }

  // Change quality measurement only if SoftClustering or other clustering method is used.
  if (quality != nullptr)
  {
    // unsigned int probas = (*m_ClusteringModel)( data );
    (*quality) = ConfidenceValueType(1.);
  }

  if (proba != nullptr)
  {
    if (!this->m_ProbaIndex)
    {
      itkExceptionMacro("Probability per class not available for this classifier !");
    }
  }
  TargetSampleType     target;
  ClusteringOutputType predictedValue = (*m_ClusteringModel)(data);
  target[0]                           = static_cast<TOutputValue>(predictedValue);
  return target;
}

template <class TInputValue, class TOutputValue>
void SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::DoPredictBatch(const InputListSampleType* input, const unsigned int& startIndex,
                                                                                const unsigned int& size, TargetListSampleType* targets,
                                                                                ConfidenceListSampleType* quality, ProbaListSampleType* proba) const
{

  // Perform check on input values
  assert(input != nullptr);
  assert(targets != nullptr);

  // input list sample and target list sample should be initialized and without
  assert(input->Size() == targets->Size() && "Input sample list and target label list do not have the same size.");
  assert(((quality == nullptr) || (quality->Size() == input->Size())) &&
         "Quality samples list is not null and does not have the same size as input samples list");
  if (startIndex + size > input->Size())
  {
    itkExceptionMacro(<< "requested range [" << startIndex << ", " << startIndex + size << "[ partially outside input sample list range.[0," << input->Size()
                      << "[");
  }

  // Convert input list of features to shark data format
  std::vector<shark::RealVector> features;
  otb::Shark::ListSampleRangeToSharkVector(input, features, startIndex, size);
  shark::Data<shark::RealVector> inputSamples = shark::createDataFromRange(features);

  shark::Data<ClusteringOutputType> clusters;
  try
  {
    clusters = (*m_ClusteringModel)(inputSamples);
  }
  catch (...)
  {
    itkExceptionMacro(
        "Failed to run clustering classification. "
        "The number of features of input samples and the model could differ.");
  }

  unsigned int id = startIndex;
  for (const auto& p : clusters.elements())
  {
    TargetSampleType target;
    target[0] = static_cast<TOutputValue>(p);
    targets->SetMeasurementVector(id, target);
    ++id;
  }

  // Change quality measurement only if SoftClustering or other clustering method is used.
  if (quality != nullptr)
  {
    for (unsigned int qid = startIndex; qid < startIndex + size; ++qid)
    {
      quality->SetMeasurementVector(qid, static_cast<ConfidenceValueType>(1.));
    }
  }
  if (proba != nullptr && !this->m_ProbaIndex)
  {
    itkExceptionMacro("Probability per class not available for this classifier !");
  }
}


template <class TInputValue, class TOutputValue>
void SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::Save(const std::string& filename, const std::string& itkNotUsed(name))
{
  std::ofstream ofs(filename);
  if (!ofs)
  {
    itkExceptionMacro(<< "Error opening " << filename.c_str());
  }
  ofs << "#" << m_ClusteringModel->name() << std::endl;
  shark::TextOutArchive oa(ofs);
  m_ClusteringModel->save(oa, 1);
}

template <class TInputValue, class TOutputValue>
void SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::Load(const std::string& filename, const std::string& itkNotUsed(name))
{
  m_CanRead = false;
  std::ifstream ifs(filename);
  if (ifs.good())
  {
    // Check if first line contains model name
    std::string line;
    std::getline(ifs, line);
    m_CanRead = line.find(m_ClusteringModel->name()) != std::string::npos;
  }

  if (!m_CanRead)
    return;

  shark::TextInArchive ia(ifs);
  m_ClusteringModel->load(ia, 0);
  ifs.close();
}

template <class TInputValue, class TOutputValue>
bool SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::CanReadFile(const std::string& file)
{
  try
  {
    m_CanRead = true;
    this->Load(file);
  }
  catch (...)
  {
    return false;
  }
  return m_CanRead;
}

template <class TInputValue, class TOutputValue>
bool SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::CanWriteFile(const std::string& itkNotUsed(file))
{
  return true;
}

template <class TInputValue, class TOutputValue>
void SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::ExportCentroids(const std::string& filename)
{
  shark::exportCSV(m_Centroids.centroids(), filename, ' ');
}

template <class TInputValue, class TOutputValue>
void SharkKMeansMachineLearningModel<TInputValue, TOutputValue>::PrintSelf(std::ostream& os, itk::Indent indent) const
{
  // Call superclass implementation
  Superclass::PrintSelf(os, indent);
}
} // end namespace otb

#endif
