/* Copyright (c) 2016 Baidu, Inc. All Rights Reserve.

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. */


#pragma once

#include "Layer.h"
#include "PoolProjection.h"
#include "paddle/utils/Logging.h"

namespace paddle {

class SpatialPyramidPoolLayer : public Layer {
protected:
  size_t channels_;
  size_t imgSizeW_;
  size_t imgSizeH_;
  size_t pyramidHeight_;
  std::string poolType_;

  std::vector<std::unique_ptr<PoolProjection>> poolProjections_;
  std::vector<Argument> projInput_;
  std::vector<Argument> projOutput_;
  std::vector<std::pair<size_t, size_t>> projCol_;

public:
  explicit SpatialPyramidPoolLayer(const LayerConfig& config) : Layer(config) {}
  ~SpatialPyramidPoolLayer() {}

  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
  ProjectionConfig getConfig(size_t sizeX_, size_t sizeY_, size_t channels,
                             size_t pyamidLevel_, std::string& poolType_);

  int outputSize(int imageSize, int windowSize, int padding, int stride) {
    return (imageSize - windowSize + 2 * padding) / stride + 1;
  }

  virtual void forward(PassType passType);
  virtual void backward(const UpdateCallback& callback = nullptr);
  void splitInput(Argument& input, size_t height, size_t width, bool useGpu);
};
}  // namespace paddle