/* Copyright (c) 2016 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 <forward_list>
#include <list>
#include <map>
#include <memory>
#include <mutex>  // NOLINT
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#include "paddle/fluid/platform/enforce.h"
#include "paddle/fluid/platform/event.h"
#include "paddle/fluid/platform/place.h"
#ifdef PADDLE_WITH_CUDA
#include "paddle/fluid/platform/gpu_info.h"
#endif
namespace paddle {
namespace platform {

enum class ProfilerState {
  kDisabled,  // disabled state
  kCPU,       // CPU profiling state
  kCUDA,      // GPU profiling state
  kAll,       // Profile both CPU and GPU. (Currently experimental).
};

void Mark(const std::string& name);

void PushMemEvent(uint64_t start_ns, uint64_t end_ns, size_t bytes,
                  const Place& place);
void PopMemEvent(uint64_t start_ns, uint64_t end_ns, size_t bytes,
                 const Place& place);

struct MemEvenRecorder {
 public:
  void PushMemRecord(const void* ptr, const Place& place, size_t size);
  void PopMemRecord(const void* ptr, const Place& place);
  void Flush();
  static MemEvenRecorder& Instance() { return recorder; }

 private:
  struct RecordMemEvent {
    RecordMemEvent(const Place& place, size_t bytes);
    ~RecordMemEvent();

    Place place_;
    size_t bytes_;
    uint64_t start_ns_;
    uint64_t end_ns_;
    std::string alloc_in_;
    std::string free_in_;
  };

  static MemEvenRecorder recorder;
  std::map<Place,
           std::unordered_map<const void*, std::unique_ptr<RecordMemEvent>>>
      address_memevent_;
  std::mutex mtx_;
  MemEvenRecorder() {}
  DISABLE_COPY_AND_ASSIGN(MemEvenRecorder);
};

Event* PushEvent(const std::string& name);
void PopEvent(const std::string& name);

struct RecordEvent {
  explicit RecordEvent(const std::string& name);

  ~RecordEvent();

  bool is_enabled_;
  uint64_t start_ns_;
  // Event name
  std::string name_;
  // Need to distinguish name by op type, block_id, program_id and perhaps
  // different kernel invocations within an op.
  std::string full_name_;
};

class RecordRPCEvent {
 public:
  explicit RecordRPCEvent(const std::string& name);
  ~RecordRPCEvent() {}

 private:
  std::unique_ptr<RecordEvent> event_;
};

struct RecordBlock {
  explicit RecordBlock(int block_id);
  ~RecordBlock();

 private:
  bool is_enabled_;
  std::string name_;
  uint64_t start_ns_;
};

// Return the event list of all threads. Assumed the returned value calls
// event_lists, event_lists[i][j] represents the j-th Event of i-th thread.
std::vector<std::vector<Event>> GetAllEvents();

// Candidate keys to sort the profiling report
enum class EventSortingKey {
  kDefault,
  kCalls,
  kTotal,
  kMin,
  kMax,
  kAve,
  kCPUTime,
  kGPUTime
};

template <typename T>
struct EventList {
  constexpr static size_t kMB = 1024 * 1024;
  constexpr static size_t kEventBlockSize = 16 * kMB;
  constexpr static size_t kEventSize = sizeof(T);
  constexpr static size_t kEventAlign = alignof(T);
  constexpr static size_t kNumBlock =
      kEventBlockSize /
      ((kEventSize + kEventAlign - 1) / kEventAlign * kEventAlign);

  template <typename... Args>
  T* Record(Args&&... args) {
    if (event_blocks.empty() || event_blocks.front().size() == kNumBlock) {
      event_blocks.emplace_front();
      event_blocks.front().reserve(kNumBlock);
    }
    event_blocks.front().emplace_back(std::forward<Args>(args)...);
    return &event_blocks.front().back();
  }

  std::vector<T> Reduce() {
    std::vector<T> result;
    for (auto& block : event_blocks) {
      result.insert(result.begin(), std::make_move_iterator(block.begin()),
                    std::make_move_iterator(block.end()));
    }
    event_blocks.clear();
    return result;
  }

  void Clear() { event_blocks.clear(); }

  std::forward_list<std::vector<T>> event_blocks;
};

// Enable the profiling function.
void EnableProfiler(ProfilerState state);

// Clear the g_all_event_lists, which is total event lists of all threads.
void ResetProfiler();

void DisableProfiler(EventSortingKey sorted_key,
                     const std::string& profile_path);

const int kEnableProfiler = 1;
const int kDisableProfiler = 2;
// Test if the profiler is currently enabled.
bool IsProfileEnabled();
// Whether the trainer should send profiling state to PS.
bool ShouldSendProfileState();
// Mark current process as PS by assigning a lister id.
void SetProfileListener();
int64_t ListenerId();

#ifdef PADDLE_WITH_CUDA
void DummyKernelAndEvent();
#endif

}  // namespace platform
}  // namespace paddle