/* 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. */

#pragma once

#include <map>
#include <memory>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#include "paddle/fluid/framework/lod_tensor.h"
#include "paddle/fluid/framework/op_registry.h"
#include "paddle/fluid/framework/tensor_util.h"
#include "paddle/fluid/inference/anakin/engine.h"
#include "paddle/fluid/inference/analysis/helper.h"
#include "paddle/fluid/inference/utils/singleton.h"
#include "paddle/fluid/platform/enforce.h"

using anakin::graph::GraphGlobalMem;
using anakin::AK_FLOAT;
using anakin::Precision;
using anakin::saber::NV;
using anakin::saber::X86;
using anakin::saber::Shape;
using anakin::PBlock;
using anakin::PTuple;

namespace paddle {
namespace inference {
namespace anakin {

/*
 * Get a random float value between [low, high]
 */
float random(float low, float high) {
  static std::random_device rd;
  static std::mt19937 mt(rd());
  std::uniform_real_distribution<double> dist(low, high);
  return dist(mt);
}

void RandomizeTensor(framework::LoDTensor* tensor, const platform::Place& place,
                     const platform::DeviceContext& ctx) {
  auto dims = tensor->dims();
  size_t num_elements = analysis::AccuDims(dims, dims.size());
  PADDLE_ENFORCE_GT(num_elements, 0);

  platform::CPUPlace cpu_place;
  framework::LoDTensor temp_tensor;
  temp_tensor.Resize(dims);
  auto* temp_data = temp_tensor.mutable_data<float>(cpu_place);

  for (size_t i = 0; i < num_elements; i++) {
    *(temp_data + i) = random(0., 1.);
  }

  TensorCopySync(temp_tensor, place, tensor);
}

/*
 * Help to validate the correctness between Fluid Op and the corresponding
 * anakin
 * layer.
 */
class AnakinConvertValidation {
  using AnakinNvEngineT = AnakinEngine<NV, Precision::FP32>;

 public:
  AnakinConvertValidation() = delete;

  AnakinConvertValidation(const std::unordered_set<std::string>& parameters,
                          const framework::Scope& scope)
      : parameters_(parameters), scope_(scope), place_(0) {
    PADDLE_ENFORCE_EQ(cudaStreamCreate(&stream_), 0);
    engine_.reset(new AnakinEngine<NV, Precision::FP32>(true));
  }

  // Declare a Variable as input with random initialization.
  void DeclInputVar(const std::string& name,
                    const std::vector<int> tensor_dims) {
    DeclVar(name, tensor_dims);
    // should decalre anakin input here.
  }

  void DeclParamVar(const std::string& name, const std::vector<int> dim_vec) {
    DeclVar(name, dim_vec);
  }

  void DeclOutputVar(const std::string& name, const std::vector<int> dim_vec) {
    DeclVar(name, dim_vec);
    // should declare anakin output here.
  }

  void DeclVar(const std::string& name, const std::vector<int> dim_vec) {
    platform::CUDADeviceContext ctx(place_);
    auto* x = scope_.Var(name);
    auto* x_tensor = x->GetMutable<framework::LoDTensor>();
    x_tensor->Resize(framework::make_ddim(dim_vec));
    RandomizeTensor(x_tensor, place_, ctx);
  }

  void SetOp(const framework::proto::OpDesc& desc) {
    op_ = framework::OpRegistry::CreateOp(desc);
    op_desc_.reset(new framework::OpDesc(desc, nullptr));
    // should init anakin engine here.

    Singleton<AnakinOpConverter>::Global().ConvertOp(
        desc, parameters_, scope_, engine_.get(), true /*test_mode*/);
    engine_->Freeze();
    for (const auto& input : op_desc_->InputArgumentNames()) {
      if (parameters_.count(input)) continue;
      auto& t = inference::analysis::GetFromScope<framework::LoDTensor>(scope_,
                                                                        input);
      auto t_shape = framework::vectorize2int(t.dims());
      engine_->SetInputShape(input, t_shape);
    }
    engine_->Optimize();
    engine_->InitGraph();
  }

  // We use the set 'neglected_output' here, because some Ops like batch norm,
  // the outputs specified in the op des are only used during training,
  // so we should neglect those output during inference.
  void Execute(int batch_size,
               std::unordered_set<std::string> neglected_output = {}) {
    // Execute Fluid Op
    platform::CUDADeviceContext ctx(place_);
    op_->Run(scope_, place_);

    // std::vector<framework::LoDTensor> input_vector;
    // std::vector<framework::LoDTensor> output_vector;
    std::map<std::string, framework::LoDTensor*> inputs;
    for (const auto& input : op_desc_->InputArgumentNames()) {
      if (parameters_.count(input)) continue;
      auto* var = scope_.FindVar(input);
      auto tensor = var->GetMutable<framework::LoDTensor>();
      inputs.insert({input, tensor});
    }

    std::map<std::string, framework::LoDTensor*> outputs;
    std::vector<std::vector<float>> fluid_outputs;
    for (const auto& output : op_desc_->OutputArgumentNames()) {
      if (neglected_output.count(output)) continue;
      std::vector<float> fluid_out;
      auto* var = scope_.FindVar(output);
      auto tensor = var->GetMutable<framework::LoDTensor>();
      framework::TensorToVector(*tensor, ctx, &fluid_out);
      fluid_outputs.push_back(fluid_out);

      // size_t fluid_out_size = fluid_out.size();
      /*for (size_t i = 0; i < fluid_out_size; i++) {
        std::cout << fluid_out[i] << std::endl;
      }*/
      outputs.insert({output, tensor});
    }

    engine_->Execute(inputs, outputs);
    int i_output = 0;
    for (const auto& output : op_desc_->OutputArgumentNames()) {
      if (neglected_output.count(output)) continue;
      std::vector<float> anakin_out;
      auto* var = scope_.FindVar(output);
      auto tensor = var->GetMutable<framework::LoDTensor>();
      framework::TensorToVector(*tensor, ctx, &anakin_out);

      size_t anakin_out_size = anakin_out.size();
      auto fluid_out = fluid_outputs[i_output++];
      for (size_t i = 0; i < anakin_out_size; i++) {
        LOG(INFO) << "Output[" << i << "]: anakin[" << anakin_out[i] << "], "
                  << "fluid[" << fluid_out[i] << "]";
      }
    }
  }

  framework::Scope& scope() { return scope_; }

 private:
  std::unique_ptr<AnakinNvEngineT> engine_{nullptr};
  cudaStream_t stream_;
  std::unique_ptr<framework::OperatorBase> op_;
  std::unique_ptr<framework::OpDesc> op_desc_;
  const std::unordered_set<std::string>& parameters_;
  framework::Scope& scope_;
  platform::CUDAPlace place_;
};

}  // namespace anakin
}  // namespace inference
}  // namespace paddle