/*
 * Copyright (C) 2005-2017 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 otbSentinel1ImageMetadataInterface_h
#define otbSentinel1ImageMetadataInterface_h

#include "otbSarImageMetadataInterface.h"


namespace otb
{
/** \class Sentinel1ImageMetadataInterface
 *
 * \brief Creation of an "otb" Sentinel1ImageMetadataInterface that gets metadata.
 *
 *
 * \ingroup OTBMetadata
 */

class OTBMetadata_EXPORT Sentinel1ImageMetadataInterface : public SarImageMetadataInterface
{
public:

  typedef Sentinel1ImageMetadataInterface    Self;
  typedef SarImageMetadataInterface         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(Sentinel1ImageMetadataInterface, SarImageMetadataInterface);

  typedef Superclass::ImageType                ImageType;
  typedef Superclass::MetaDataDictionaryType   MetaDataDictionaryType;
  typedef Superclass::VectorType               VectorType;
  typedef Superclass::VariableLengthVectorType VariableLengthVectorType;
  typedef Superclass::ImageKeywordlistType     ImageKeywordlistType;
  typedef Superclass::RealType                  RealType;
  typedef Superclass::LookupDataPointerType LookupDataPointerType;

  /** Get the imaging production day from the ossim metadata : DATASET_PRODUCTION_DATE metadata variable */
  int GetProductionDay() const override;

  /** Get the imaging production month from the ossim metadata : DATASET_PRODUCTION_DATE metadata variable */
  int GetProductionMonth() const override;

  /** Get the imaging production year from the ossim metadata : DATASET_PRODUCTION_DATE metadata variable */
  int GetProductionYear() const override;

  /** check sensor ID */
  bool CanRead() const override;

  int GetDay() const override;

  int GetMonth() const override;

  int GetYear() const override;

  int GetHour() const override;

  int GetMinute() const override;

  UIntVectorType GetDefaultDisplay() const override;

  /*SarImageMetadataInterface pure virutals rituals */
  double GetPRF() const override;

  double GetRSF() const override;

  double GetRadarFrequency() const override;

  double GetCenterIncidenceAngle() const override;

  /*get lookup data for calculating backscatter */
  void CreateCalibrationLookupData(const short type) override;

protected:

  /* class ctor */
  Sentinel1ImageMetadataInterface();

  /* class dtor */
  ~Sentinel1ImageMetadataInterface() override {}

private:

  Sentinel1ImageMetadataInterface(const Self &); //purposely not implemented
  void operator =(const Self&); //purposely not implemented

/* Helper function to parse date and time into a std::vector<std::string>
 * using boost::split() expect date time in yyyy-mm-ddThh:mm:ss.ms
 * the date-time string is to be found in keywordlist with key 'key'
 * fills argument dateFields of type std::vector<std::string> which is mutable!
 * TODO: move this method into base class
 */
  void ParseDateTime(const char* key, std::vector<int>& dateFields) const;

  mutable std::vector<int> m_ProductionDateFields;
  mutable std::vector<int> m_AcquisitionDateFields;
};



struct Sentinel1CalibrationStruct
{
public:
  double timeMJD;
  double deltaMJD; // time difference to previous MJD in the list
  int line;
  std::vector<int> pixels;
  std::vector<double> deltaPixels;
  std::vector<float> vect;
};

class Sentinel1CalibrationLookupData : public SarCalibrationLookupData
{
public:

  /** Standard typedefs */
  typedef Sentinel1CalibrationLookupData   Self;
  typedef SarCalibrationLookupData         Superclass;
  typedef itk::SmartPointer<Self>          Pointer;
  typedef itk::SmartPointer<const Self>    ConstPointer;

  /** Creation through the object factory */
  itkNewMacro(Self);

  /** RTTI */
  itkTypeMacro(Sentinel1CalibrationLookupData, SarCalibrationLookupData);

  typedef itk::IndexValueType IndexValueType;

  Sentinel1CalibrationLookupData()
    : firstLineTime(0.)
    , lastLineTime(0.)
    , numOfLines(0)
    , count(0)
    , lineTimeInterval(0.)
  {
  }

  ~Sentinel1CalibrationLookupData() override
  {
  }

  void InitParameters(short type, double ft, double lt,
                      int lines, int c,
                      std::vector<Sentinel1CalibrationStruct> const& vlist)
  {
    firstLineTime = ft;
    lastLineTime = lt;
    numOfLines = lines;
    count = c;
    calibrationVectorList = vlist;
    this->SetType(type);
    lineTimeInterval = (lt - ft) / ((lines - 1) * 1.0);
  }

  double GetValue(const IndexValueType x, const IndexValueType y) const override
  {
    const int calVecIdx = GetVectorIndex(y);
    assert(calVecIdx>=0 && calVecIdx < count-1);
    const Sentinel1CalibrationStruct & vec0 = calibrationVectorList[calVecIdx];
    const Sentinel1CalibrationStruct & vec1 = calibrationVectorList[calVecIdx + 1];
    const double azTime = firstLineTime + y * lineTimeInterval;
    const double muY = (azTime - vec0.timeMJD) / vec1.deltaMJD;
    const int pixelIdx = GetPixelIndex(x, calibrationVectorList[calVecIdx]);
    const double muX = (x - vec0.pixels[pixelIdx]) / vec0.deltaPixels[pixelIdx + 1];
    const double lutVal
        = (1 - muY) * ((1 - muX) * vec0.vect[pixelIdx] + muX * vec0.vect[pixelIdx + 1])
        +       muY * ((1 - muX) * vec1.vect[pixelIdx] + muX * vec1.vect[pixelIdx + 1]);
    return lutVal;
  }

  int GetVectorIndex(int y) const
  {
    for (int i = 1; i < count; i++)
      {
      if (y < calibrationVectorList[i].line)
        {
        return i - 1;
        }
      }
    return -1;
  }

  int GetPixelIndex(int x, const Sentinel1CalibrationStruct& calVec) const
  {
      const int size = calVec.pixels.size();
      std::vector<int>::const_iterator wh = std::upper_bound(calVec.pixels.begin(), calVec.pixels.end(), x);
      return wh == calVec.pixels.end() ? size - 2 : std::distance(calVec.pixels.begin(),wh)-1;
  }

private:

  Sentinel1CalibrationLookupData(const Self&); //purposely not implemented

  void operator =(const Self&); //purposely not implemented

  double firstLineTime;
  double lastLineTime;
  int numOfLines;
  int count;
  std::vector<Sentinel1CalibrationStruct> calibrationVectorList;
  double lineTimeInterval;
};


} // end namespace otb

#endif
