/* Copyright 2015 Google Inc. 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.
==============================================================================*/

// See docs in ../ops/image_ops.cc
#define EIGEN_USE_THREADS

#include "tensorflow/core/kernels/adjust_contrast_op.h"
#include <memory>
#include "third_party/eigen3/unsupported/Eigen/CXX11/Tensor"
#include "tensorflow/core/framework/op_kernel.h"
#include "tensorflow/core/framework/register_types.h"
#include "tensorflow/core/framework/tensor.h"
#include "tensorflow/core/framework/tensor_shape.h"
#include "tensorflow/core/framework/types.h"
#include "tensorflow/core/lib/core/status.h"
#include "tensorflow/core/platform/logging.h"

namespace tensorflow {

typedef Eigen::ThreadPoolDevice CPUDevice;
typedef Eigen::GpuDevice GPUDevice;

// AdjustContrastOp is deprecated as of GraphDef version >= 2

template <typename Device, typename T>
class AdjustContrastOp : public OpKernel {
 public:
  explicit AdjustContrastOp(OpKernelConstruction* context) : OpKernel(context) {
    OP_DEPRECATED(context, 2, "Use AdjustContrastv2 instead");
  }

  void Compute(OpKernelContext* context) override {
    const Tensor& input = context->input(0);
    const Tensor& factor = context->input(1);
    const Tensor& min_value = context->input(2);
    const Tensor& max_value = context->input(3);
    OP_REQUIRES(context, input.dims() >= 3,
                errors::InvalidArgument("input must be at least 3-D, got shape",
                                        input.shape().DebugString()));
    const int64 height = input.dim_size(input.dims() - 3);
    const int64 width = input.dim_size(input.dims() - 2);
    const int64 channels = input.dim_size(input.dims() - 1);

    OP_REQUIRES(context, TensorShapeUtils::IsScalar(factor.shape()),
                errors::InvalidArgument("contrast_factor must be scalar: ",
                                        factor.shape().DebugString()));
    OP_REQUIRES(context, TensorShapeUtils::IsScalar(min_value.shape()),
                errors::InvalidArgument("min_value must be scalar: ",
                                        min_value.shape().DebugString()));
    OP_REQUIRES(context, TensorShapeUtils::IsScalar(max_value.shape()),
                errors::InvalidArgument("max_value must be scalar: ",
                                        max_value.shape().DebugString()));

    Tensor* output = nullptr;
    OP_REQUIRES_OK(context,
                   context->allocate_output(0, input.shape(), &output));

    Tensor mean_values;
    OP_REQUIRES_OK(context, context->allocate_temp(DataTypeToEnum<float>::value,
                                                   TensorShape(input.shape()),
                                                   &mean_values));

    if (input.NumElements() > 0) {
      const int64 batch = input.NumElements() / (height * width * channels);
      const int64 shape[4] = {batch, height, width, channels};
      functor::AdjustContrast<Device, T>()(
          context->eigen_device<Device>(), input.shaped<T, 4>(shape),
          factor.scalar<float>(), min_value.scalar<float>(),
          max_value.scalar<float>(), mean_values.shaped<float, 4>(shape),
          output->shaped<float, 4>(shape));
    }
  }
};

#define REGISTER_KERNEL(T)                                              \
  REGISTER_KERNEL_BUILDER(                                              \
      Name("AdjustContrast").Device(DEVICE_CPU).TypeConstraint<T>("T"), \
      AdjustContrastOp<CPUDevice, T>);

REGISTER_KERNEL(uint8);
REGISTER_KERNEL(int8);
REGISTER_KERNEL(int16);
REGISTER_KERNEL(int32);
REGISTER_KERNEL(float);
REGISTER_KERNEL(double);
#undef REGISTER_KERNEL

#if GOOGLE_CUDA
// Forward declarations of the function specializations for GPU (to prevent
// building the GPU versions here, they will be built compiling _gpu.cu.cc).
namespace functor {
#define DECLARE_GPU_SPEC(T)                                         \
  template <>                                                       \
  void AdjustContrast<GPUDevice, T>::operator()(                    \
      const GPUDevice& d, typename TTypes<T, 4>::ConstTensor input, \
      typename TTypes<float>::ConstScalar contrast_factor,          \
      typename TTypes<float>::ConstScalar min_value,                \
      typename TTypes<float>::ConstScalar max_value,                \
      typename TTypes<float, 4>::Tensor mean_values,                \
      typename TTypes<float, 4>::Tensor output);                    \
  extern template struct AdjustContrast<GPUDevice, T>;

DECLARE_GPU_SPEC(uint8);
DECLARE_GPU_SPEC(int8);
DECLARE_GPU_SPEC(int16);
DECLARE_GPU_SPEC(int32);
DECLARE_GPU_SPEC(float);
DECLARE_GPU_SPEC(double);
#undef DECLARE_GPU_SPEC
}  // namespace functor

// Registration of the GPU implementations.
#define REGISTER_GPU_KERNEL(T)                                          \
  REGISTER_KERNEL_BUILDER(                                              \
      Name("AdjustContrast").Device(DEVICE_GPU).TypeConstraint<T>("T"), \
      AdjustContrastOp<GPUDevice, T>);
REGISTER_GPU_KERNEL(uint8);
REGISTER_GPU_KERNEL(int8);
REGISTER_GPU_KERNEL(int16);
REGISTER_GPU_KERNEL(int32);
REGISTER_GPU_KERNEL(float);
REGISTER_GPU_KERNEL(double);
#undef REGISTER_GPU_KERNEL

#endif  // GOOGLE_CUDA

template <typename Device>
class AdjustContrastOpv2 : public OpKernel {
 public:
  explicit AdjustContrastOpv2(OpKernelConstruction* context)
      : OpKernel(context) {}

  void Compute(OpKernelContext* context) override {
    const Tensor& input = context->input(0);
    const Tensor& factor = context->input(1);
    OP_REQUIRES(context, input.dims() >= 3,
                errors::InvalidArgument("input must be at least 3-D, got shape",
                                        input.shape().DebugString()));
    const int64 height = input.dim_size(input.dims() - 3);
    const int64 width = input.dim_size(input.dims() - 2);
    const int64 channels = input.dim_size(input.dims() - 1);

    OP_REQUIRES(context, TensorShapeUtils::IsScalar(factor.shape()),
                errors::InvalidArgument("contrast_factor must be scalar: ",
                                        factor.shape().DebugString()));

    Tensor* output = nullptr;
    OP_REQUIRES_OK(context,
                   context->allocate_output(0, input.shape(), &output));

    if (input.NumElements() > 0) {
      const int64 batch = input.NumElements() / (height * width * channels);
      const int64 shape[4] = {batch, height, width, channels};
      functor::AdjustContrastv2<Device>()(
          context->eigen_device<Device>(), input.shaped<float, 4>(shape),
          factor.scalar<float>(), output->shaped<float, 4>(shape));
    }
  }
};

REGISTER_KERNEL_BUILDER(Name("AdjustContrastv2").Device(DEVICE_CPU),
                        AdjustContrastOpv2<CPUDevice>);

#if GOOGLE_CUDA
// Forward declarations of the function specializations for GPU (to prevent
// building the GPU versions here, they will be built compiling _gpu.cu.cc).
namespace functor {
template <>
void AdjustContrastv2<GPUDevice>::operator()(
    const GPUDevice& d, typename TTypes<float, 4>::ConstTensor input,
    typename TTypes<float>::ConstScalar contrast_factor,
    typename TTypes<float, 4>::Tensor output);
extern template struct AdjustContrastv2<GPUDevice>;
#undef DECLARE_GPU_SPEC
}  // namespace functor

REGISTER_KERNEL_BUILDER(Name("AdjustContrastv2").Device(DEVICE_GPU),
                        AdjustContrastOpv2<GPUDevice>);

#endif  // GOOGLE_CUDA

}  // namespace tensorflow
