/* -*- c++ -*- */
/*
 * gr-satnogs: SatNOGS GNU Radio Out-Of-Tree Module
 *
 *  Copyright (C) 2017,2018 Libre Space Foundation <http://librespacefoundation.org/>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef INCLUDED_SATNOGS_NOAA_APT_SINK_IMPL_H
#define INCLUDED_SATNOGS_NOAA_APT_SINK_IMPL_H

#include <satnogs/noaa_apt_sink.h>
#define PNG_DEBUG 3
#include <png++/png.hpp>
#include <chrono>



namespace gr {
namespace satnogs {
enum class noaa_apt_sync_marker {SYNC_A, SYNC_B, NONE};

class noaa_apt_sink_impl : public noaa_apt_sink {
private:
  // Factor exponential smoothing average,
  // which is used for sync pattern detection
  const float f_average_alpha;
  static const bool synca_seq[];
  static const bool syncb_seq[];

  std::string d_filename_png;
  size_t d_width;
  size_t d_height;
  bool d_synchronize_opt;
  bool d_flip;
  size_t d_history_length;
  bool d_has_sync;
  bool d_image_received;

  png::image<png::gray_pixel> d_full_image;
  png::image<png::gray_pixel> d_left_image;
  png::image<png::gray_pixel> d_right_image;
  std::string d_full_filename;
  std::string d_left_filename;
  std::string d_right_filename;

  size_t d_current_x;
  size_t d_current_y;
  size_t d_num_images;

  float f_max_level;
  float f_min_level;
  float f_average;

public:
  noaa_apt_sink_impl(const char *filename_png, size_t width, size_t height,
                     bool sync, bool flip);
  ~noaa_apt_sink_impl();

  // Where all the action really happens
  int
  work(int noutput_items, gr_vector_const_void_star &input_items,
       gr_vector_void_star &output_items);

  bool
  stop();
private:

  /*
   * Checks if the history portion of the input contains a sync marker.
   * Matches the 40 samples before pos against the patterns.
   */
  noaa_apt_sync_marker
  is_marker(size_t pos, const float *samples);

  // Sets the pixel indicated by coordinates in the images (both full and split)
  void
  set_pixel(size_t x, size_t y, float sample);

  /*
   * Updates d_current_x to new_x,
   * while using historical samples to fill any resulting gaps in the images.
   */
  void
  skip_to(size_t new_x, size_t pos, const float *samples);

  // Writes a single image to disk, also takes care of flipping
  void
  write_image(png::image<png::gray_pixel> image, std::string filename);
};

} // namespace satnogs
} // namespace gr

#endif /* INCLUDED_SATNOGS_NOAA_APT_SINK_IMPL_H */