/*
 * Copyright (c) 2018 Samsung Electronics Co., Ltd. All Rights Reserved
 *
 * 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.
 */

#ifndef __NEURUN_UTIL_FEATURE_NCHW_VIEW_H__
#define __NEURUN_UTIL_FEATURE_NCHW_VIEW_H__

#include "misc/feature/Reader.h"
#include "misc/feature/Shape.h"

#include "backend/interface/operand/ITensor.h"
#include "util/feature/Coordinate4D.h"

#include <cassert>

namespace neurun
{
namespace util
{
namespace feature
{
namespace nchw
{

template <typename T> class View final : public nnfw::misc::feature::Reader<T>
{
public:
  View(::neurun::backend::operand::ITensor *tensor) : _tensor{tensor}
  {
    // TODO Validate whether tensor is a feature map, or not
    _shape.N = tensor->dimension(3);
    _shape.C = tensor->dimension(2);
    _shape.H = tensor->dimension(1);
    _shape.W = tensor->dimension(0);
  }

public:
  const ::nnfw::misc::feature::Shape &shape(void) const { return _shape; }

public:
  T at(uint32_t ch, uint32_t row, uint32_t col) const override
  {
    const auto offset = feature_index_to_byte_offset(0, ch, row, col);

    T *ptr = reinterpret_cast<T *>(_tensor->buffer() + offset);

    return *ptr;
  }
  T at(uint32_t batch, uint32_t ch, uint32_t row, uint32_t col) const override
  {
    const auto offset = feature_index_to_byte_offset(batch, ch, row, col);

    T *ptr = reinterpret_cast<T *>(_tensor->buffer() + offset);

    return *ptr;
  }

public:
  T &at(uint32_t ch, uint32_t row, uint32_t col)
  {
    const auto offset = feature_index_to_byte_offset(0, ch, row, col);

    T *ptr = reinterpret_cast<T *>(_tensor->buffer() + offset);

    return *ptr;
  }
  T &at(uint32_t batch, uint32_t ch, uint32_t row, uint32_t col)
  {
    const auto offset = feature_index_to_byte_offset(batch, ch, row, col);

    T *ptr = reinterpret_cast<T *>(_tensor->buffer() + offset);

    return *ptr;
  }

private:
  size_t feature_index_to_byte_offset(uint32_t batch, uint32_t ch, uint32_t row, uint32_t col) const
  {
    return _tensor->calcOffset(
        neurun::util::feature::Coordinate4D{static_cast<int32_t>(batch), static_cast<int32_t>(row),
                                            static_cast<int32_t>(col), static_cast<int32_t>(ch)});
  }

private:
  ::nnfw::misc::feature::Shape _shape;
  ::neurun::backend::operand::ITensor *_tensor;
};

} // namespace nchw
} // namespace feature
} // namespace util
} // namespace neurun

#endif // __NEURUN_UTIL_FEATURE_NCHW_VIEW_H__