/* Copyright 2018 The TensorFlow Authors. 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 TENSORFLOW_CONTRIB_IGNITE_KERNELS_IGNITE_BYTE_SWAPPER_H_
#define TENSORFLOW_CONTRIB_IGNITE_KERNELS_IGNITE_BYTE_SWAPPER_H_

#include <stdint.h>
#include "tensorflow/core/platform/byte_order.h"

namespace tensorflow {

class ByteSwapper {
 public:
  ByteSwapper(bool big_endian) { swap_ = big_endian == port::kLittleEndian; }

  inline void SwapIfRequiredInt16(int16_t *x) const {
    if (swap_) {
      Swap16(x);
    }
  }

  inline void SwapIfRequiredUnsignedInt16(uint16_t *x) const {
    if (swap_) {
      Swap16(reinterpret_cast<int16_t *>(x));
    }
  }

  inline void SwapIfRequiredInt32(int32_t *x) const {
    if (swap_) {
      Swap32(x);
    }
  }

  inline void SwapIfRequiredFloat(float *x) const {
    if (swap_) {
      Swap32(reinterpret_cast<int32_t *>(x));
    }
  }

  inline void SwapIfRequiredInt64(int64_t *x) const {
    if (swap_) {
      Swap64(x);
    }
  }

  inline void SwapIfRequiredDouble(double *x) const {
    if (swap_) {
      Swap64(reinterpret_cast<int64_t *>(x));
    }
  }

  inline void SwapIfRequiredInt16Arr(int16_t *x, int32_t length) const {
    if (swap_) {
      for (int32_t i = 0; i < length; i++) Swap16(&x[i]);
    }
  }

  inline void SwapIfRequiredUnsignedInt16Arr(uint16_t *x,
                                             int32_t length) const {
    if (swap_) {
      for (int32_t i = 0; i < length; i++)
        Swap16(reinterpret_cast<int16_t *>(&x[i]));
    }
  }

  inline void SwapIfRequiredInt32Arr(int32_t *x, int32_t length) const {
    if (swap_) {
      for (int32_t i = 0; i < length; i++) Swap32(&x[i]);
    }
  }

  inline void SwapIfRequiredFloatArr(float *x, int32_t length) const {
    if (swap_) {
      for (int32_t i = 0; i < length; i++)
        Swap32(reinterpret_cast<int32_t *>(&x[i]));
    }
  }

  inline void SwapIfRequiredInt64Arr(int64_t *x, int32_t length) const {
    if (swap_) {
      for (int32_t i = 0; i < length; i++) Swap64(&x[i]);
    }
  }

  inline void SwapIfRequiredDoubleArr(double *x, int32_t length) const {
    if (swap_) {
      for (int32_t i = 0; i < length; i++)
        Swap64(reinterpret_cast<int64_t *>(&x[i]));
    }
  }

 private:
  inline void Swap16(int16_t *x) const {
    *x = ((*x & 0xFF) << 8) | ((*x >> 8) & 0xFF);
  }

  inline void Swap32(int32_t *x) const {
    *x = ((*x & 0xFF) << 24) | (((*x >> 8) & 0xFF) << 16) |
         (((*x >> 16) & 0xFF) << 8) | ((*x >> 24) & 0xFF);
  }

  inline void Swap64(int64_t *x) const {
    *x = ((*x & 0xFF) << 56) | (((*x >> 8) & 0xFF) << 48) |
         (((*x >> 16) & 0xFF) << 40) | (((*x >> 24) & 0xFF) << 32) |
         (((*x >> 32) & 0xFF) << 24) | (((*x >> 40) & 0xFF) << 16) |
         (((*x >> 48) & 0xFF) << 8) | ((*x >> 56) & 0xFF);
  }

  bool swap_;
};

}  // namespace tensorflow

#endif  // TENSORFLOW_CONTRIB_IGNITE_KERNELS_IGNITE_BYTE_SWAPPER_H_