/* SPDX-License-Identifier: GPL-2.0-or-later
 * Copyright 2011 Blender Foundation. */

#pragma once

#include "COM_MultiThreadedOperation.h"
#include "DNA_node_types.h"
#include <functional>

namespace blender::compositor {

/**
 * \brief base class of CalculateMean, implementing the simple CalculateMean
 * \ingroup operation
 */
class CalculateMeanOperation : public MultiThreadedOperation {
 public:
  struct PixelsSum {
    float sum;
    int num_pixels;
  };

 protected:
  /**
   * \brief Cached reference to the reader
   */
  SocketReader *image_reader_;

  bool iscalculated_;
  float result_;
  int setting_;
  std::function<float(const float *elem)> setting_func_;

 public:
  CalculateMeanOperation();

  /**
   * The inner loop of this operation.
   */
  void execute_pixel(float output[4], int x, int y, void *data) override;

  /**
   * Initialize the execution
   */
  void init_execution() override;

  void *initialize_tile_data(rcti *rect) override;

  /**
   * Deinitialize the execution
   */
  void deinit_execution() override;

  bool determine_depending_area_of_interest(rcti *input,
                                            ReadBufferOperation *read_operation,
                                            rcti *output) override;
  void set_setting(int setting);

  void get_area_of_interest(int input_idx, const rcti &output_area, rcti &r_input_area) override;

  virtual void update_memory_buffer_started(MemoryBuffer *output,
                                            const rcti &area,
                                            Span<MemoryBuffer *> inputs) override;

  virtual void update_memory_buffer_partial(MemoryBuffer *output,
                                            const rcti &area,
                                            Span<MemoryBuffer *> inputs) override;

 protected:
  void calculate_mean(MemoryBuffer *tile);
  float calc_mean(const MemoryBuffer *input);

 private:
  PixelsSum calc_area_sum(const MemoryBuffer *input, const rcti &area);
};

}  // namespace blender::compositor