/* 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 <sys/time.h>
#include <time.h>
#include <fstream>
#include <thread>  // NOLINT
#include "gflags/gflags.h"
#include "gtest/gtest.h"
#include "paddle/fluid/inference/tests/test_helper.h"
#ifdef PADDLE_WITH_MKLML
#include <mkl_service.h>
#include <omp.h>
#endif

DEFINE_string(modelpath, "", "Directory of the inference model.");
DEFINE_string(datafile, "", "File of input index data.");
DEFINE_int32(repeat, 100, "Running the inference program repeat times");
DEFINE_bool(use_mkldnn, false, "Use MKLDNN to run inference");
DEFINE_bool(prepare_vars, true, "Prepare variables before executor");
DEFINE_int32(num_threads, 1, "Number of threads should be used");

inline double GetCurrentMs() {
  struct timeval time;
  gettimeofday(&time, NULL);
  return 1e+3 * time.tv_sec + 1e-3 * time.tv_usec;
}

// Load the input word index data from file and save into LodTensor.
// Return the size of words.
size_t LoadData(std::vector<paddle::framework::LoDTensor>* out,
                const std::string& filename) {
  size_t sz = 0;
  std::fstream fin(filename);
  std::string line;
  out->clear();
  while (getline(fin, line)) {
    std::istringstream iss(line);
    std::vector<int64_t> ids;
    std::string field;
    while (getline(iss, field, ' ')) {
      ids.push_back(stoi(field));
    }
    if (ids.size() >= 1024) {
      continue;
    }

    paddle::framework::LoDTensor words;
    paddle::framework::LoD lod{{0, ids.size()}};
    words.set_lod(lod);
    int64_t* pdata = words.mutable_data<int64_t>(
        {static_cast<int64_t>(ids.size()), 1}, paddle::platform::CPUPlace());
    memcpy(pdata, ids.data(), words.numel() * sizeof(int64_t));
    out->emplace_back(words);
    sz += ids.size();
  }
  return sz;
}

// Split input data samples into small pieces jobs as balanced as possible,
// according to the number of threads.
void SplitData(
    const std::vector<paddle::framework::LoDTensor>& datasets,
    std::vector<std::vector<const paddle::framework::LoDTensor*>>* jobs,
    const int num_threads) {
  size_t s = 0;
  jobs->resize(num_threads);
  while (s < datasets.size()) {
    for (auto it = jobs->begin(); it != jobs->end(); it++) {
      it->emplace_back(&datasets[s]);
      s++;
      if (s >= datasets.size()) {
        break;
      }
    }
  }
}

void ThreadRunInfer(
    const int tid, paddle::framework::Executor* executor,
    paddle::framework::Scope* scope,
    const std::unique_ptr<paddle::framework::ProgramDesc>& inference_program,
    const std::vector<std::vector<const paddle::framework::LoDTensor*>>& jobs) {
  auto copy_program = std::unique_ptr<paddle::framework::ProgramDesc>(
      new paddle::framework::ProgramDesc(*inference_program));
  auto& sub_scope = scope->NewScope();

  std::string feed_holder_name = "feed_" + paddle::string::to_string(tid);
  std::string fetch_holder_name = "fetch_" + paddle::string::to_string(tid);
  copy_program->SetFeedHolderName(feed_holder_name);
  copy_program->SetFetchHolderName(fetch_holder_name);

  const std::vector<std::string>& feed_target_names =
      copy_program->GetFeedTargetNames();
  const std::vector<std::string>& fetch_target_names =
      copy_program->GetFetchTargetNames();

  PADDLE_ENFORCE_EQ(fetch_target_names.size(), 1UL);
  std::map<std::string, paddle::framework::LoDTensor*> fetch_targets;
  paddle::framework::LoDTensor outtensor;
  fetch_targets[fetch_target_names[0]] = &outtensor;

  std::map<std::string, const paddle::framework::LoDTensor*> feed_targets;
  PADDLE_ENFORCE_EQ(feed_target_names.size(), 1UL);

  auto& inputs = jobs[tid];
  auto start_ms = GetCurrentMs();
  for (size_t i = 0; i < inputs.size(); ++i) {
    feed_targets[feed_target_names[0]] = inputs[i];
    executor->Run(*copy_program, &sub_scope, &feed_targets, &fetch_targets,
                  true /*create_local_scope*/, true /*create_vars*/,
                  feed_holder_name, fetch_holder_name);
  }
  auto stop_ms = GetCurrentMs();
  scope->DeleteScope(&sub_scope);
  LOG(INFO) << "Tid: " << tid << ", process " << inputs.size()
            << " samples, avg time per sample: "
            << (stop_ms - start_ms) / inputs.size() << " ms";
}

TEST(inference, nlp) {
  if (FLAGS_modelpath.empty() || FLAGS_datafile.empty()) {
    LOG(FATAL) << "Usage: ./example --modelpath=path/to/your/model "
               << "--datafile=path/to/your/data";
  }
  LOG(INFO) << "Model Path: " << FLAGS_modelpath;
  LOG(INFO) << "Data File: " << FLAGS_datafile;

  std::vector<paddle::framework::LoDTensor> datasets;
  size_t num_total_words = LoadData(&datasets, FLAGS_datafile);
  LOG(INFO) << "Number of samples (seq_len<1024): " << datasets.size();
  LOG(INFO) << "Total number of words: " << num_total_words;

  const bool model_combined = false;
  // 0. Call `paddle::framework::InitDevices()` initialize all the devices
  // 1. Define place, executor, scope
  auto place = paddle::platform::CPUPlace();
  auto executor = paddle::framework::Executor(place);
  std::unique_ptr<paddle::framework::Scope> scope(
      new paddle::framework::Scope());

  // 2. Initialize the inference_program and load parameters
  std::unique_ptr<paddle::framework::ProgramDesc> inference_program;
  inference_program =
      InitProgram(&executor, scope.get(), FLAGS_modelpath, model_combined);
  if (FLAGS_use_mkldnn) {
    EnableMKLDNN(inference_program);
  }

#ifdef PADDLE_WITH_MKLML
  // only use 1 thread number per std::thread
  omp_set_dynamic(0);
  omp_set_num_threads(1);
  mkl_set_num_threads(1);
#endif

  double start_ms = 0, stop_ms = 0;
  if (FLAGS_num_threads > 1) {
    std::vector<std::vector<const paddle::framework::LoDTensor*>> jobs;
    SplitData(datasets, &jobs, FLAGS_num_threads);
    std::vector<std::unique_ptr<std::thread>> threads;
    for (int i = 0; i < FLAGS_num_threads; ++i) {
      threads.emplace_back(
          new std::thread(ThreadRunInfer, i, &executor, scope.get(),
                          std::ref(inference_program), std::ref(jobs)));
    }
    start_ms = GetCurrentMs();
    for (int i = 0; i < FLAGS_num_threads; ++i) {
      threads[i]->join();
    }
    stop_ms = GetCurrentMs();
  } else {
    if (FLAGS_prepare_vars) {
      executor.CreateVariables(*inference_program, scope.get(), 0);
    }
    // always prepare context
    std::unique_ptr<paddle::framework::ExecutorPrepareContext> ctx;
    ctx = executor.Prepare(*inference_program, 0);

    // preapre fetch
    const std::vector<std::string>& fetch_target_names =
        inference_program->GetFetchTargetNames();
    PADDLE_ENFORCE_EQ(fetch_target_names.size(), 1UL);
    std::map<std::string, paddle::framework::LoDTensor*> fetch_targets;
    paddle::framework::LoDTensor outtensor;
    fetch_targets[fetch_target_names[0]] = &outtensor;

    // prepare feed
    const std::vector<std::string>& feed_target_names =
        inference_program->GetFeedTargetNames();
    PADDLE_ENFORCE_EQ(feed_target_names.size(), 1UL);
    std::map<std::string, const paddle::framework::LoDTensor*> feed_targets;

    // feed data and run
    start_ms = GetCurrentMs();
    for (size_t i = 0; i < datasets.size(); ++i) {
      feed_targets[feed_target_names[0]] = &(datasets[i]);
      executor.RunPreparedContext(ctx.get(), scope.get(), &feed_targets,
                                  &fetch_targets, !FLAGS_prepare_vars);
    }
    stop_ms = GetCurrentMs();
    LOG(INFO) << "Tid: 0, process " << datasets.size()
              << " samples, avg time per sample: "
              << (stop_ms - start_ms) / datasets.size() << " ms";
  }
  LOG(INFO) << "Total inference time with " << FLAGS_num_threads
            << " threads : " << (stop_ms - start_ms) / 1000.0
            << " sec, QPS: " << datasets.size() / ((stop_ms - start_ms) / 1000);
}