// Copyright (c) 2018 Graphcore Ltd. All rights reserved.
#include <string>
#include <poplar/Tensor.hpp>
#include <popnn/NonLinearity.hpp>
#include <popnn/NonLinearityDef.hpp>
#include <popart/op/relu.hpp>
#include <popart/popx/op/relux.hpp>
#include <popart/popx/opxmanager.hpp>

#include "popart/operators.hpp"
#include "popart/popx/debugcontextx.hpp"
#include "popart/popx/op/elementwisex.hpp"
#include "popart/popx/opx.hpp"

namespace poplar {
class Graph;
namespace program {
class Sequence;
} // namespace program
} // namespace poplar

namespace popart {
class Op;

namespace popx {
class Devicex;

ReluInplaceOpx::ReluInplaceOpx(Op *op, Devicex *devicex)
    : ElementWiseUnaryInplaceOpx(op, devicex, ReluComputex::get()) {
  verifyOp<ReluInplaceOp>(op, Onnx::CustomOperators::ReluInplace);
}

ReluOpx::ReluOpx(Op *op, Devicex *devicex)
    : ElementWiseUnaryOutplaceOpx(op, devicex, ReluComputex::get()) {
  verifyOp<ReluOp>(op, Onnx::Operators::Relu_6);
}

poplar::Tensor ReluComputex::outplace(poplar::program::Sequence &p,
                                      poplar::Graph &g,
                                      const poplar::Tensor &t,
                                      const poplar::DebugNameAndId &dnai,
                                      const std::string &s) const {
  auto outTensor = cloneNcopy(p, g, t, dnai);
  inplace(p, g, outTensor, dnai, s);
  return outTensor;
}

void ReluComputex::inplace(poplar::program::Sequence &p,
                           poplar::Graph &g,
                           const poplar::Tensor &t,
                           const poplar::DebugNameAndId &dnai,
                           const std::string &s) const {

  // apply the inplace RELU
  popnn::nonLinearityInPlace(g, popnn::NonLinearityType::RELU, t, p, {dnai, s});
}

ReluGradOpx::ReluGradOpx(Op *op, Devicex *devicex) : Opx(op, devicex) {
  verifyOp<ReluGradOp>(op, Onnx::GradOperators::ReluGrad);
}

void ReluGradOpx::grow(poplar::program::Sequence &prog) const {

  ReluGradOp &rgop = getOp<ReluGradOp>();

  auto outTensor = popnn::nonLinearityInputGradient(
      graph(),                                 // graph,
      popnn::NonLinearityType::RELU,           // nonLinearityType,
      getInTensor(rgop.getReludInIndex()),     // out,
      getInTensor(rgop.getGradReludInIndex()), // outGradient,
      prog,                                    // prog,
      debugContext()                           // debugContext
  );

  setOutTensor(0, outTensor);
}

namespace {
OpxCreator<ReluOpx> reluxOpxCreator(Onnx::Operators::Relu_6);
OpxCreator<ReluInplaceOpx>
    reluxInplaceOpxCreator(Onnx::CustomOperators::ReluInplace);
OpxCreator<ReluGradOpx> reluxGradOpxCreator(Onnx::GradOperators::ReluGrad);
} // namespace

} // namespace popx
} // namespace popart