/* The copyright in this software is being made available under the BSD
 * License, included below. This software may be subject to other third party
 * and contributor rights, including patent rights, and no such rights are
 * granted under this license.
 *
 * Copyright (c) 2010-2022, ITU/ISO/IEC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
 *    be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * THE POSSIBILITY OF SUCH DAMAGE.
 */
#pragma once
#include <cmath>

#include "layer.h"

namespace sadl
{
namespace layers
{
template<typename T> class Const : public Layer<T>
{
public:
  using Layer<T>::Layer;
  using Layer<T>::out_;   // to avoid this->
  using Layer<T>::initDone_;

  virtual bool apply(std::vector<Tensor<T> *> &in) override;
  virtual bool init(const std::vector<Tensor<T> *> &in) override;

protected:
  virtual bool              loadInternal(std::istream &file, Version v) override;
  template<typename U> void readTensor(std::istream &file, Tensor<T> &out);
  DUMP_MODEL_EXT;
};

template<typename T> bool Const<T>::apply(std::vector<Tensor<T> *> &in)
{
  assert(in.size() == 0);
  (void) in;
  // assert(ptr==ptr)
  return true;
}

template<typename T> bool Const<T>::init(const std::vector<Tensor<T> *> &in)
{
  if (in.size() != 0)
    return false;
  initDone_ = true;
  return true;
}

template<typename T> template<typename U> void Const<T>::readTensor(std::istream &file, Tensor<T> &out)
{
  if (std::is_same<T, U>::value)
    file.read((char *) out.data(), sizeof(T) * out.size());
  else
  {
    std::vector<U> data(out.size());
    file.read((char *) data.data(), sizeof(U) * data.size());
    for (int k = 0; k < (int) data.size(); ++k)
      out[k] = static_cast<T>(data[k]);
  }
}

template<typename T> bool Const<T>::loadInternal(std::istream &file, Version v)
{
  // load values
  int32_t x = 0;
  file.read((char *) &x, sizeof(x));
  if (x <= 0 || x > Dimensions::MaxDim)
  {
    std::cerr << "[ERROR] invalid nb of dimensions: " << x << std::endl;
    return false;
  }
  Dimensions d;
  d.resize(x);
  for (int k = 0; k < d.size(); ++k)
  {
    file.read((char *) &x, sizeof(x));
    d[k] = x;
  }

  if (d.nbElements() >= Tensor<T>::kMaxSize)
  {
    std::cerr << "[ERROR] tensor too large? " << d.nbElements() << std::endl;
    return false;
  }
  out_.resize(d);
  SADL_DBG(std::cout << "  - tensor: " << out_.dims() << std::endl);

  file.read((char *) &x, sizeof(x));

  // cannot check internal type because tensor also used by reshape etc.
  switch (x)
  {
  case TensorInternalType::Int32:
    // assert((std::is_same<T,int32_t>::value));
    file.read((char *) &out_.quantizer, sizeof(out_.quantizer));
    readTensor<int32_t>(file, out_);
    break;
  case TensorInternalType::Float:
    // assert((std::is_same<T, float>::value));
    readTensor<float>(file, out_);
    break;
  case TensorInternalType::Int16:
    // assert((std::is_same<T, int16_t>::value));
    file.read((char *) &out_.quantizer, sizeof(out_.quantizer));
    readTensor<int16_t>(file, out_);
    break;
  default: std::cerr << "[ERROR] unknown internal type " << x << std::endl; return false;
  }

  SADL_DBG(std::cout << "  - data: "; for (int k = 0; k < 4 && k < out_.size(); ++k) std::cout << out_[k] << ' '; std::cout << " ...\n");
  SADL_DBG(std::cout << "  - quantizer: " << out_.quantizer << std::endl);
  // SADL_DBG(std::cout<<out_<<std::endl;)
  return true;
}

}   // namespace layers
}   // namespace sadl
