/* Copyright (c) 2020 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 <vector>
#include "paddle/fluid/framework/tensor.h"
#include "paddle/fluid/platform/miopen_helper.h"

namespace paddle {
namespace operators {

class ScopedRNNBase {
 public:
  ScopedRNNBase(int seq_length, int batch_size, int input_size, int hidden_size,
                int num_layers, float dropout_prob, int seed, int weight_numel,
                bool initialized, bool is_bidirec)
      : seq_length_(seq_length),
        batch_size_(batch_size),
        input_size_(input_size),
        hidden_size_(hidden_size),
        num_layers_(num_layers),
        dropout_prob_(dropout_prob),
        seed_(seed),
        weight_numel_(weight_numel),
        initialized_(initialized),
        is_bidirec_(is_bidirec) {}

  template <typename T>
  void Create(const miopenHandle_t& handle, const platform::Place& place,
              const std::vector<int>& sequence_length, size_t* workspace_size,
              size_t* reserve_size, framework::Tensor* dropout_state) {
    int numDirections = is_bidirec_ ? 2 : 1;
    miopenDataType_t miopen_type = platform::CudnnDataType<T>::type;

    // ------------------- miopen x, y descriptors ---------------------
    std::vector<int> dims_x = {batch_size_, input_size_, 1};
    std::vector<int> strides_x = {input_size_, 1, 1};
    std::vector<int> dims_y = {batch_size_, hidden_size_ * numDirections, 1};
    std::vector<int> strides_y = {hidden_size_ * numDirections, 1, 1};
    for (int i = 0; i < seq_length_; ++i) {
      x_descs_.emplace_back(x_desc_.descriptor<T>(dims_x, strides_x));
      y_descs_.emplace_back(y_desc_.descriptor<T>(dims_y, strides_y));
    }

    // ------------------- miopen hx, hy, cx, cy descriptors----------
    std::vector<int> dims_hx = {num_layers_ * numDirections, batch_size_,
                                hidden_size_};
    std::vector<int> strides_hx = {hidden_size_ * batch_size_, hidden_size_, 1};
    init_h_desc_.descriptor<T>(dims_hx, strides_hx);
    init_c_desc_.descriptor<T>(dims_hx, strides_hx);
    last_h_desc_.descriptor<T>(dims_hx, strides_hx);
    last_c_desc_.descriptor<T>(dims_hx, strides_hx);

    // ------------------- miopen dropout descriptors ---------------------
    size_t state_size;
    if (!initialized_) {
      PADDLE_ENFORCE_CUDA_SUCCESS(
          platform::dynload::miopenDropoutGetStatesSize(handle, &state_size));
      dropout_state->mutable_data<uint8_t>({static_cast<int64_t>(state_size)},
                                           place);
    }
    dropout_desc_.descriptor(handle, place, initialized_, dropout_prob_,
                             dropout_state, seed_, state_size);

    // ------------------- miopen rnn descriptors ---------------------
    PADDLE_ENFORCE_CUDA_SUCCESS(platform::dynload::miopenSetRNNDescriptor(
        rnn_desc_.desc(), hidden_size_, num_layers_, miopenRNNlinear,
        is_bidirec_ ? miopenRNNbidirection : miopenRNNunidirection, miopenLSTM,
        miopenRNNNoBias, miopenRNNdefault, miopen_type));

    // ------------------- miopen weights_size ---------------------
    size_t weights_size_;
    PADDLE_ENFORCE_CUDA_SUCCESS(platform::dynload::miopenGetRNNParamsSize(
        handle, rnn_desc_.desc(), x_descs_[0], &weights_size_, miopen_type));
    PADDLE_ENFORCE_EQ(
        weights_size_, sizeof(T) * weight_numel_,
        platform::errors::InvalidArgument(
            "The miopen lstm and setting weight size should be same."));
    // ------------------- miopen weight descriptors ---------------------
    platform::DataLayout layout = platform::DataLayout::kNCHW;
    int dim_tmp = weights_size_ / sizeof(T);
    std::vector<int> dim_w = {dim_tmp, 1, 1};
    weight_desc_.descriptor<T>(layout, dim_w);
    // ------------------- miopen workspace, reserve size ---------------------
    PADDLE_ENFORCE_CUDA_SUCCESS(platform::dynload::miopenGetRNNWorkspaceSize(
        handle, rnn_desc_.desc(), seq_length_, x_descs_.data(),
        workspace_size));
    PADDLE_ENFORCE_CUDA_SUCCESS(
        platform::dynload::miopenGetRNNTrainingReserveSize(
            handle, rnn_desc_.desc(), seq_length_, x_descs_.data(),
            reserve_size));
  }
  miopenTensorDescriptor_t* x_descs() { return x_descs_.data(); }
  miopenTensorDescriptor_t* y_descs() { return y_descs_.data(); }
  miopenTensorDescriptor_t init_h_desc() { return init_h_desc_.desc(); }
  miopenTensorDescriptor_t init_c_desc() { return init_c_desc_.desc(); }
  miopenTensorDescriptor_t last_h_desc() { return last_h_desc_.desc(); }
  miopenTensorDescriptor_t last_c_desc() { return last_c_desc_.desc(); }
  miopenRNNDescriptor_t rnn_desc() { return rnn_desc_.desc(); }
  miopenDropoutDescriptor_t dropout_desc() { return dropout_desc_.desc(); }
  miopenTensorDescriptor_t weight_desc() { return weight_desc_.desc(); }

 private:
  int seq_length_;
  int batch_size_;
  int input_size_;
  int hidden_size_;
  int num_layers_;
  float dropout_prob_;
  int seed_;
  int weight_numel_;
  bool initialized_;
  bool is_bidirec_;
  std::vector<miopenTensorDescriptor_t> x_descs_;
  std::vector<miopenTensorDescriptor_t> y_descs_;

  platform::ScopedTensorDescriptor x_desc_;
  platform::ScopedTensorDescriptor y_desc_;
  platform::ScopedTensorDescriptor init_h_desc_;
  platform::ScopedTensorDescriptor init_c_desc_;
  platform::ScopedTensorDescriptor last_h_desc_;
  platform::ScopedTensorDescriptor last_c_desc_;
  platform::ScopedDropoutDescriptor dropout_desc_;
  platform::ScopedFilterDescriptor weight_desc_;
  platform::ScopedRNNDescriptor rnn_desc_;
};

}  // namespace operators
}  // namespace paddle