/* 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 <atomic>
#include <fstream>
#include <map>
#include <memory>
#include <mutex>  // NOLINT
#include <string>
#include <thread>         // NOLINT
#include <unordered_map>  // NOLINT
#include <unordered_set>  // NOLINT
#include <utility>        // NOLINT
#include <vector>

#include "paddle/fluid/framework/data_feed.h"
#include "paddle/fluid/framework/lod_tensor.h"
#include "paddle/fluid/framework/op_registry.h"
#include "paddle/fluid/framework/program_desc.h"
#include "paddle/fluid/framework/reader.h"
#include "paddle/fluid/framework/trainer_desc.pb.h"
#include "paddle/fluid/framework/variable_helper.h"
#include "paddle/fluid/operators/reader/blocking_queue.h"
#include "paddle/fluid/platform/place.h"
#include "paddle/fluid/platform/port.h"
#include "paddle/fluid/platform/timer.h"

#if defined(PADDLE_WITH_NCCL)
#include "paddle/fluid/platform/nccl_helper.h"
#endif

namespace paddle {
namespace framework {

std::string PrintLodTensor(Tensor* tensor, int64_t start, int64_t end);
std::pair<int64_t, int64_t> GetTensorBound(LoDTensor* tensor, int index);
bool CheckValidOutput(LoDTensor* tensor, size_t batch_size);

class FleetWrapper;

class PullDenseWorker {
 public:
  virtual ~PullDenseWorker() {}
  virtual void Initialize(const TrainerDesc& param);
  int Start();
  void Stop();
  void SetRootScope(Scope* scope) { root_scope_ = scope; }
  void IncreaseThreadVersion(int thread_id, uint64_t table_id);
  void ResetThreadVersion(uint64_t table_id);
  void Wait(std::vector<::std::future<int32_t>>* status_vec);
  void PullDense(bool force_update = false);
  int GetThreadIdByScope(const Scope* scope);
  void SetThreadIdByScope(const Scope* scope, int tid);
  static std::shared_ptr<PullDenseWorker> GetInstance() {
    if (NULL == s_instance_) {
      s_instance_.reset(new paddle::framework::PullDenseWorker());
    }
    return s_instance_;
  }

  static std::shared_ptr<PullDenseWorker> s_instance_;

 private:
  PullDenseWorker() : root_scope_(NULL) {}
  void Run();
  bool CheckUpdateParam(uint64_t table_id);

 private:
  std::shared_ptr<paddle::framework::FleetWrapper> fleet_ptr_;
  PullDenseWorkerParameter param_;
  DownpourWorkerParameter dwp_param_;
  Scope* root_scope_;
  bool running_;

  static std::map<uint64_t, uint64_t> last_versions_;
  static std::map<uint64_t, uint64_t> current_version_;
  static std::mutex mutex_for_version_;
  static std::map<uint64_t, std::vector<uint64_t>> training_versions_;
  static std::map<uint64_t, std::vector<std::string>> dense_value_names_;

  std::thread t_;
  int thread_num_;
  int sleep_time_ms_;
  int threshold_;

  std::vector<::std::future<int32_t>> pull_dense_status_;
  uint32_t pull_dense_fail_times_ = 0;
  std::vector<float> base_norm_param_;
  std::vector<float> mean_;
  std::vector<float> scale_;
  float squared_sum_epsilon_ = 1e-4;
  std::mutex mutex_for_mean_scale_;
  float total_batch_num_ = 0;
  std::unordered_map<const Scope*, int> scope_to_thread_id_;
};

// should incorporate different type of device
class DeviceWorker {
 public:
  DeviceWorker() {
    no_cvm_ = true;
    use_cvm_ = false;
  }
  virtual ~DeviceWorker() {}
  virtual void Initialize(const TrainerDesc& desc) = 0;
  virtual void InitRandomDumpConfig(const TrainerDesc& desc);
  virtual void SetDeviceIndex(int tid) = 0;
  virtual void TrainFiles() = 0;
  virtual void PrintFetchVars() = 0;
  virtual void TrainFilesWithProfiler() = 0;
  virtual void CreateDeviceResource(const ProgramDesc& main_prog) = 0;
  // will make this zero copy in the future
  virtual void BindingDataFeedMemory() = 0;
  virtual void SetRootScope(Scope* root_scope);
  virtual void SetDataFeed(DataFeed* data_feed);
  virtual void SetNeedDumpField(bool need_dump_field) {
    need_dump_field_ = need_dump_field;
  }
  virtual void SetNeedDumpParam(bool need_dump_param) {
    need_dump_param_ = need_dump_param;
  }
  virtual void SetDumpFieldVector(const std::vector<std::string>& dump_fields) {
    dump_fields_ = &dump_fields;
  }
  virtual void SetDumpParamVector(const std::vector<std::string>& dump_param) {
    dump_param_ = &dump_param;
  }
  virtual void SetChannelWriter(ChannelObject<std::string>* queue) {
    writer_.Reset(queue);
  }
  virtual void SetPlace(const paddle::platform::Place& place) {
    place_ = place;
  }
  virtual void SetReaderPlace(const paddle::platform::Place& place) {
    device_reader_->SetPlace(place);
  }
  virtual Scope* GetThreadScope() { return thread_scope_; }

 protected:
  virtual void DumpParam(const Scope& scope, const int batch_id);
  virtual void DumpField(const Scope& scope, int dump_mode,
                         int dump_interval = 10000);
  Scope* root_scope_ = nullptr;
  Scope* thread_scope_;
  paddle::platform::Place place_;
  DataFeed* device_reader_ = nullptr;
  int64_t batch_num_;
  FetchConfig fetch_config_;
  bool use_cvm_;
  bool no_cvm_;

  // dump params or grads for debug
  bool need_dump_param_;
  bool need_dump_field_;
  const std::vector<std::string>* dump_param_;
  const std::vector<std::string>* dump_fields_;
  std::vector<std::string> all_param_;

  int dump_mode_ = 0;
  int dump_interval_ = 10000;
  ChannelWriter<std::string> writer_;
};

class CPUWorkerBase : public DeviceWorker {
 public:
  CPUWorkerBase() {}
  virtual ~CPUWorkerBase() {}
  virtual void SetDeviceIndex(int tid) { thread_id_ = tid; }
  virtual void TrainFiles() = 0;
  virtual void TrainFilesWithProfiler() {}
  virtual void PrintFetchVars() {}
  virtual void CreateDeviceResource(const ProgramDesc& main_prog) {}

 protected:
  int thread_id_;
};

class HogwildWorker : public CPUWorkerBase {
 public:
  HogwildWorker() {}
  virtual ~HogwildWorker() {
    for (OperatorBase* op : ops_) {
      delete op;
    }
    std::vector<OperatorBase*>().swap(ops_);
  }
  virtual void Initialize(const TrainerDesc& desc);
  virtual void TrainFiles();
  virtual void TrainFilesWithProfiler();
  virtual void PrintFetchVars();
  virtual void CreateDeviceResource(const ProgramDesc& main_prog);
  virtual void BindingDataFeedMemory();
  template <typename T>
  void SetZero(LoDTensor* tensor, LoDTensor* root_tensor, int tensor_dim);

 protected:
  void CreateThreadOperators(const ProgramDesc& program);
  void CreateThreadScope(const ProgramDesc& program);

  std::vector<std::string> op_names_;
  std::vector<OperatorBase*> ops_;
  bool thread_barrier_;
  // Scope* thread_scope_;
  HogwildWorkerParameter param_;
  std::vector<std::string> skip_ops_;
  std::map<std::string, int> stat_var_name_map_;
};

class DownpourWorker : public HogwildWorker {
 public:
  DownpourWorker() {}
  virtual ~DownpourWorker() {}
  virtual void Initialize(const TrainerDesc& desc);
  virtual void TrainFiles();
  virtual void TrainFilesWithProfiler();

 protected:
  std::shared_ptr<paddle::framework::FleetWrapper> fleet_ptr_;
  std::shared_ptr<paddle::framework::PullDenseWorker> pull_dense_worker_;
  void FillSparseValue(size_t table_id);
  void PushGradients();
  void CollectLabelInfo(size_t table_id);
  void AdjustInsWeight();
  void CopySparseTable();
  void CopyDenseTable();
  void CopyDenseVars();

  DownpourWorkerParameter param_;
  // copy table
  CopyTableConfig copy_table_config_;
  std::vector<std::pair<uint64_t, uint64_t>> copy_sparse_tables_;
  std::unordered_map<uint64_t, std::unordered_set<uint64_t>> feasign_set_;
  // actually pushed feasign of each table
  std::map<uint64_t, std::vector<uint64_t>> sparse_push_keys_;
  std::map<uint64_t, std::vector<std::string>> sparse_key_names_;
  // feasign
  std::map<uint64_t, std::vector<uint64_t>> features_;
  // feasign embedding
  std::map<uint64_t, std::vector<std::vector<float>>> feature_values_;
  std::map<uint64_t, std::vector<std::string>> sparse_value_names_;
  // adjust ins weight
  AdjustInsWeightConfig adjust_ins_weight_config_;
  // check nan and inf during training
  std::vector<std::string> check_nan_var_names_;
  bool need_to_push_sparse_;
  // feasign stats
  std::map<uint64_t, std::vector<float>> feature_labels_;
  std::map<uint64_t, std::vector<std::string>> sparse_grad_names_;
  // feasign embedding gradient
  std::map<uint64_t, std::vector<std::vector<float>>> feature_grads_;
  std::vector<::std::future<int32_t>> push_sparse_status_;
  bool dump_slot_;
  bool need_to_push_dense_;
  std::map<uint64_t, std::vector<std::string>> dense_grad_names_;
  float scale_datanorm_;
  std::vector<::std::future<int32_t>> push_dense_status_;
  // skipped ops
  std::vector<std::string> skip_ops_;
  // just save the value in param_ for easy access
  std::map<uint64_t, std::string> label_var_name_;
  std::map<uint64_t, std::vector<std::string>> dense_value_names_;
  std::map<uint64_t, uint64_t> table_dependency_;
  std::vector<std::pair<uint64_t, uint64_t>> copy_dense_tables_;

 private:
  // std::vector<std::string> dump_param_;
  // just save the value in param_ for easy access
  // std::map<uint64_t, std::string> label_var_name_;
  // std::map<uint64_t, std::vector<std::string>> dense_value_names_;

  std::shared_ptr<PullDenseWorker> _pull_dense_worker;

  std::vector<float> nid_show_;
  // std::map<uint64_t, uint64_t> table_dependency_;
  // std::vector<std::pair<uint64_t, uint64_t>> copy_dense_tables_;
};

class DownpourWorkerOpt : public DownpourWorker {
 public:
  DownpourWorkerOpt() {}
  virtual ~DownpourWorkerOpt() {}
  virtual void CreateDeviceResource(const ProgramDesc& main_prog);
  virtual void Initialize(const TrainerDesc& desc);
  virtual void TrainFiles();

 protected:
  void CreateThreadOperatorsWithRerank(const ProgramDesc& program);
  std::vector<std::vector<OperatorBase*>> loss_ops_;
  std::vector<std::vector<std::string>> loss_op_names_;
  std::vector<std::string> loss_names_;
  std::string async_wait_name_;
  int async_index_ = -1;
  uint64_t async_tid_ = 0;
};

#if defined(PADDLE_WITH_NCCL)
class SectionWorker : public DeviceWorker {
 public:
  SectionWorker() { local_batch_id_ = 0; }
  ~SectionWorker() override {}

  void Initialize(const TrainerDesc& desc) override;

  void BindingDataFeedMemory() override {}
  void CreateDeviceResource(const ProgramDesc& main_prog) override{};

  void TrainFiles() override;
  void TrainFilesWithProfiler() override;

  void PrintFetchVars() override {}

  const platform::Place& place() const { return place_; }

  void SetSectionIndex(int section_id) { section_id_ = section_id; }
  void SetDeviceIndex(int tid) override {}
  void SetThreadIndex(int thread_id) { thread_id_ = thread_id; }
  void SetMicrobatchNum(int num) { num_microbatches_ = num; }
  void SetMicrobatchScopes(const std::vector<Scope*>& scope) {
    microbatch_scopes_ = scope;
  }
  void SetMinibatchScope(const Scope* scope) { minibatch_scope_ = scope; }
  void SetSkipVars(const std::vector<std::string>& skip_vars) {
    skip_vars_ = skip_vars;
  }

  static std::atomic<int> cpu_id_;

 protected:
  void AutoSetCPUAffinity(bool reuse);
  int section_id_;
  int thread_id_;
  int num_microbatches_;
  std::vector<Scope*> microbatch_scopes_;
  std::vector<std::string> skip_vars_;
  const Scope* minibatch_scope_;

  std::vector<std::unique_ptr<OperatorBase>> ops_;
  static std::mutex thread_mutex;
  static std::condition_variable thread_condition;
  static bool threads_completed;
  std::shared_ptr<framework::ProgramDesc> program_;
  static uint64_t batch_id_;
  uint64_t local_batch_id_;

  platform::DeviceContext* dev_ctx_ = nullptr;
};
#endif

}  // namespace framework
}  // namespace paddle