// Copyright (c) 2018 PaddlePaddle 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.

#include "paddle/fluid/operators/isfinite_op.h"
#include <string>
#include <vector>

namespace paddle {
namespace operators {

class OverflowOp : public framework::OperatorWithKernel {
 public:
  OverflowOp(const std::string &type, const framework::VariableNameMap &inputs,
             const framework::VariableNameMap &outputs,
             const framework::AttributeMap &attrs)
      : OperatorWithKernel(type, inputs, outputs, attrs) {}

  void InferShape(framework::InferShapeContext *ctx) const override {
    PADDLE_ENFORCE(ctx->HasInputs("X"), "Inputs(X) should not be null");
    PADDLE_ENFORCE(ctx->HasOutput("Out"),
                   "Output(Out) of OverflowOp should not be null.");

    ctx->SetOutputDim("Out", {1});
  }

 protected:
  framework::OpKernelType GetExpectedKernelType(
      const framework::ExecutionContext &ctx) const override {
    int dtype = -1;
    auto *x_var = ctx.InputVar("X");
    if (x_var->IsType<framework::LoDTensor>()) {
      dtype = framework::ToDataType(x_var->Get<framework::LoDTensor>().type());
    } else if (x_var->IsType<framework::SelectedRows>()) {
      dtype = framework::ToDataType(
          x_var->Get<framework::SelectedRows>().value().type());
    } else {
      PADDLE_THROW("Cannot find the input data type by all input data");
    }
    return framework::OpKernelType(framework::proto::VarType::Type(dtype),
                                   ctx.GetPlace());
  }
};

class OverflowOpMaker : public framework::OpProtoAndCheckerMaker {
 public:
  void Make() override {
    AddInput("X", "(Tensor) The input tensors of overflow operator.");
    AddOutput("Out",
              "(Tensor) 1-dim tensor, contains a bool scalar. The output "
              "tensor of overflow operator.");
    AddComment(string::Sprintf(R"DOC(
Overflow operator.

$$Out = any(X)$$

If any X contains Inf or Nan, the Out will generate a indicator.
Out = Inf if any X contains Inf,
Out = Nan if any X contains Nan,
Out = 0 if no Inf/Nan detected.
If X contains both Inf/Nan, it will return the first indicator it meeted.
)DOC",
                               GetName(), GetComments()));
  }

 protected:
  virtual std::string GetName() const = 0;
  virtual std::string GetComments() const = 0;
};

}  // namespace operators
}  // namespace paddle

namespace ops = paddle::operators;

#define REGISTER_OP_MAKER(op_type, comment)             \
  namespace paddle {                                    \
  namespace operators {                                 \
  class _##op_type##OverflowOpMaker                     \
      : public ::paddle::operators::OverflowOpMaker {   \
   protected:                                           \
    std::string GetName() const { return #op_type; }    \
    std::string GetComments() const { return comment; } \
  };                                                    \
  }                                                     \
  }                                                     \
  REGISTER_OPERATOR(op_type, ops::OverflowOp,           \
                    ops::_##op_type##OverflowOpMaker,   \
                    paddle::framework::EmptyGradOpMaker)

#define REGISTER_OVERFLOW_CPU_KERNEL(op_type, functor)                      \
  REGISTER_OP_CPU_KERNEL(                                                   \
      op_type, ops::OverflowKernel<paddle::platform::CPUDeviceContext, int, \
                                   ops::functor>,                           \
      ops::OverflowKernel<paddle::platform::CPUDeviceContext, float,        \
                          ops::functor>,                                    \
      ops::OverflowKernel<paddle::platform::CPUDeviceContext, double,       \
                          ops::functor>);

REGISTER_OP_MAKER(isinf, "isinf(X)");
REGISTER_OP_MAKER(isnan, "isnan(X)");
REGISTER_OP_MAKER(isfinite, "isfinite(X)");
FOR_EACH_KERNEL_FUNCTOR(REGISTER_OVERFLOW_CPU_KERNEL);