FitsImageSource.cpp

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/*
 * FitsImageSource.cpp
 *
 *  Created on: Mar 21, 2018
 *      Author: mschefer
 */

#include "SEFramework/FITS/FitsImageSource.h"
#include "SEFramework/FITS/FitsFile.h"
#include "SEUtils/VariantCast.h"
#include <AlexandriaKernel/memory_tools.h>
#include <ElementsKernel/Exception.h>
#include <boost/algorithm/string/case_conv.hpp>
#include <boost/algorithm/string/trim.hpp>
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/regex.hpp>
#include <fstream>
#include <iomanip>
#include <numeric>
#include <string>

namespace SourceXtractor {

using Euclid::make_unique;

namespace {

ImageTile::ImageType convertImageType(int bitpix) {
  ImageTile::ImageType image_type;

  switch (bitpix) {
  case FLOAT_IMG:
    image_type = ImageTile::FloatImage;
    break;
  case DOUBLE_IMG:
    image_type = ImageTile::DoubleImage;
    break;
  case LONG_IMG:
    image_type = ImageTile::IntImage;
    break;
  case ULONG_IMG:
    image_type = ImageTile::UIntImage;
    break;
  case LONGLONG_IMG:
    image_type = ImageTile::LongLongImage;
    break;
  default:
    throw Elements::Exception() << "Unsupported FITS image type: " << bitpix;
  }

  return image_type;
}

}

FitsImageSource::FitsImageSource(const std::string& filename, int hdu_number,
                                 ImageTile::ImageType image_type,
                                 std::shared_ptr<FileManager> manager)
    : m_filename(filename)
    , m_file_manager(std::move(manager))
    , m_handler(m_file_manager->getFileHandler(filename))
    , m_hdu_number(hdu_number) {
  int status = 0;
  int bitpix, naxis;
  long naxes[3] = {1, 1, 1};

  auto acc = m_handler->getAccessor<FitsFile>();
  auto fptr = acc->m_fd.getFitsFilePtr();

  if (m_hdu_number <= 0) {
    if (fits_get_hdu_num(fptr, &m_hdu_number) < 0) {
      throw Elements::Exception() << "Can't get the active HDU from the FITS file: " << filename;
    }
  }
  else {
    switchHdu(fptr, m_hdu_number);
  }

  fits_get_img_param(fptr, 2, &bitpix, &naxis, naxes, &status);
  if (status != 0 || (naxis != 2 && naxis != 3)) {
    throw Elements::Exception()
        << "Can't find 2D image or data cube in FITS file: " << filename << "[" << m_hdu_number << "]";
  }

  m_width = naxes[0];
  m_height = naxes[1];
  m_depth = naxis >= 3 ? naxes[2] : 1;

  if (image_type < 0) {
    m_image_type = convertImageType(bitpix);
  }
  else {
    m_image_type = image_type;
  }
}

FitsImageSource::FitsImageSource(const std::string& filename, int width, int height, ImageTile::ImageType image_type,
                                 const std::shared_ptr<CoordinateSystem> coord_system, bool append, bool empty_primary,
                                 std::shared_ptr<FileManager> manager)
    : m_filename(filename)
    , m_file_manager(std::move(manager))
    , m_handler(m_file_manager->getFileHandler(filename))
    , m_width(width)
    , m_height(height)
    , m_image_type(image_type) {

  int status = 0;
  fitsfile* fptr = nullptr;

  if (!append) {
    // delete file if it exists already
    boost::filesystem::remove(m_filename);
  }

  {
    auto acc  = m_handler->getAccessor<FitsFile>(FileHandler::kWrite);
    fptr = acc->m_fd.getFitsFilePtr();

    assert(fptr != nullptr);

    if (empty_primary &&  acc->m_fd.getImageHdus().empty()) {
      fits_create_img(fptr, FLOAT_IMG, 0, nullptr, &status);
      if (status != 0) {
        throw Elements::Exception() << "Can't create empty hdu: " << filename << " status: " << status;
      }
    }

    long naxes[2] = {width, height};
    fits_create_img(fptr, getImageType(), 2, naxes, &status);

    if (fits_get_hdu_num(fptr, &m_hdu_number) < 0) {
      throw Elements::Exception() << "Can't get the active HDU from the FITS file: " << filename << " status: " << status;
    }

    int hdutype = 0;
    fits_movabs_hdu(fptr, m_hdu_number, &hdutype, &status);

    if (coord_system) {
      auto headers = coord_system->getFitsHeaders();
      for (const auto& h : headers) {
        std::ostringstream padded_key, serializer;
        padded_key << std::setw(8) << std::left << h.first;

        serializer << padded_key.str() << "= " << std::left << std::setw(70) << h.second;
        auto str = serializer.str();

        fits_update_card(fptr, padded_key.str().c_str(), str.c_str(), &status);
        if (status != 0) {
          char err_txt[31];
          fits_get_errstatus(status, err_txt);
          throw Elements::Exception() << "Couldn't write the WCS headers (" << err_txt << "): " << str << " status: " << status;
        }
      }
    }

    std::vector<char> buffer(width * ImageTile::getTypeSize(image_type));
    for (int i = 0; i < height; i++) {
      long first_pixel[2] = {1, i + 1};
      fits_write_pix(fptr, getDataType(), first_pixel, width, &buffer[0], &status);
    }

    if (status != 0) {
      throw Elements::Exception() << "Couldn't allocate space for new FITS file: " << filename << " status: " << status;
    }

    acc->m_fd.refresh(); // make sure changes to the file structure are taken into account

  }

  // work around for canonical name bug:
  // our file's canonical name might be wrong if it didn't exist, so we need to make sure we get the correct handler
  // after we created the file

  m_handler = nullptr;
  m_handler = m_file_manager->getFileHandler(filename);
}

std::shared_ptr<ImageTile> FitsImageSource::getImageTile(int x, int y, int width, int height) const {
  auto acc  = m_handler->getAccessor<FitsFile>();
  auto fptr = acc->m_fd.getFitsFilePtr();
  switchHdu(fptr, m_hdu_number);

  auto tile = ImageTile::create(m_image_type, x, y, width, height,
                                std::const_pointer_cast<ImageSource>(shared_from_this()));

  long first_pixel[3] = {x + 1, y + 1, m_current_layer+1};
  long last_pixel[3] = {x + width, y + height, m_current_layer+1};
  long increment[3] = {1, 1, 1};
  int status = 0;

  fits_read_subset(fptr, getDataType(), first_pixel, last_pixel, increment,
                   nullptr, tile->getDataPtr(), nullptr, &status);
  if (status != 0) {
    throw Elements::Exception() << "Error reading image tile from FITS file.";
  }

  return tile;
}

void FitsImageSource::saveTile(ImageTile& tile) {
  auto acc  = m_handler->getAccessor<FitsFile>(FileHandler::kWrite);
  auto fptr = acc->m_fd.getFitsFilePtr();
  switchHdu(fptr, m_hdu_number);

  int x = tile.getPosX();
  int y = tile.getPosY();
  int width = tile.getWidth();
  int height = tile.getHeight();

  long first_pixel[2] = {x + 1, y + 1};
  long last_pixel[2] = {x + width, y + height};
  int status = 0;

  fits_write_subset(fptr, getDataType(), first_pixel, last_pixel, tile.getDataPtr(), &status);
  if (status != 0) {
    throw Elements::Exception() << "Error saving image tile to FITS file.";
  }
  fits_flush_buffer(fptr, 0, &status);
}

void FitsImageSource::switchHdu(fitsfile *fptr, int hdu_number) const {
  int status = 0;
  int hdu_type = 0;

  fits_movabs_hdu(fptr, hdu_number, &hdu_type, &status);

  if (status != 0) {
    throw Elements::Exception() << "Could not switch to HDU # " << hdu_number << " in file "
                                << m_filename;
  }
  if (hdu_type != IMAGE_HDU) {
    throw Elements::Exception() << "Trying to access non-image HDU in file " << m_filename;
  }
}

void FitsImageSource::setLayer(int layer) {
  if (layer < 0 && layer >= m_depth) {
    throw Elements::Exception() << "Trying to access an inexistent data cube layer (" << layer << ") in " << m_filename;
  }
  m_current_layer = layer;
}

std::unique_ptr<std::vector<char>> FitsImageSource::getFitsHeaders(int& number_of_records) const {
  number_of_records = 0;
  std::string records;

  auto& headers = getMetadata();
  for (const auto& record : headers) {
    const auto& key = record.first;

    std::string record_string(key);
    if (record_string.size() > 8) {
      throw Elements::Exception() << "FITS keyword longer than 8 characters";
    }
    else if (record_string.size() < 8) {
      record_string += std::string(8 - record_string.size(), ' ');
    }

    if (headers.at(key).m_value.type() == typeid(std::string)) {
      record_string += "= '" + VariantCast<std::string>(headers.at(key).m_value) + "'";
    }
    else {
      record_string += "= " + VariantCast<std::string>(headers.at(key).m_value);
    }

    if (record_string.size() > 80) {
      throw Elements::Exception() << "FITS record longer than 80 characters";
    }


    if (record_string.size() < 80) {
      record_string += std::string(80 - record_string.size(), ' ');
    }

    records += record_string;
    number_of_records++;
  }

  std::string record_string("END");
  record_string += std::string(80 - record_string.size(), ' ');
  records += record_string;

  auto buffer = make_unique<std::vector<char>>(records.begin(), records.end());
  buffer->emplace_back(0);
  return buffer;
}

const std::map<std::string, MetadataEntry>& FitsImageSource::getMetadata() const {
  auto acc = m_handler->getAccessor<FitsFile>();
  return acc->m_fd.getHDUHeaders(m_hdu_number);
}

void FitsImageSource::setMetadata(const std::string& key, const MetadataEntry& value) {
  auto acc  = m_handler->getAccessor<FitsFile>();
  auto fptr = acc->m_fd.getFitsFilePtr();
  switchHdu(fptr, m_hdu_number);

  std::ostringstream padded_key, serializer;
  padded_key << std::setw(8) << std::left << key;

  serializer << padded_key.str() << "= " << std::left << std::setw(70)
             << VariantCast<std::string>(value.m_value);
  auto str = serializer.str();

  int status = 0;
  fits_update_card(fptr, padded_key.str().c_str(), str.c_str(), &status);

  if (status != 0) {
    char err_txt[31];
    fits_get_errstatus(status, err_txt);
    throw Elements::Exception() << "Couldn't write the metadata (" << err_txt << "): " << str;
  }

  // update the metadata
  acc->m_fd.getHDUHeaders(m_hdu_number)[key] = value;
}

int FitsImageSource::getDataType() const {
  switch (m_image_type) {
    default:
    case ImageTile::FloatImage:
      return TFLOAT;
    case ImageTile::DoubleImage:
      return TDOUBLE;
    case ImageTile::IntImage:
      return TINT;
    case ImageTile::UIntImage:
      return TUINT;
    case ImageTile::LongLongImage:
      return TLONGLONG;
  }
}

int FitsImageSource::getImageType() const {
  switch (m_image_type) {
    default:
    case ImageTile::FloatImage:
      return FLOAT_IMG;
    case ImageTile::DoubleImage:
      return DOUBLE_IMG;
    case ImageTile::IntImage:
      return LONG_IMG;
    case ImageTile::UIntImage:
      return ULONG_IMG;
    case ImageTile::LongLongImage:
      return LONGLONG_IMG;
  }
}

//FIXME add missing types

}