// Copyright 2016 Google Inc. All Rights Reserved.

#ifndef WVCDM_PROFILER_SESSION_H_
#define WVCDM_PROFILER_SESSION_H_

#include <map>
#include <stddef.h>
#include <stdint.h>
#include <vector>

#include "circular_buffer.h"
#include "entry_writer.h"
#include "oem_functions.h"
#include "stats.h"

namespace wvcdm {
namespace oemprofiler {

class ProfilerSession {

 public:
  ProfilerSession();

  void Submit(
      OEM_FUNCTION fid,
      uint64_t start_time,
      uint64_t end_time,
      const uint8_t* meta_data,
      size_t meta_data_length);

  // clear all samples and stats
  void Clear();

  void ReadHistory(std::vector<uint8_t>& output) const;

  void ReadAllStats(std::vector<uint8_t>& output) const;
  const Stat& ReadStat(OEM_FUNCTION fid) const;

  static void Open(int64_t sid);
  static void Close(int64_t sid);

  static ProfilerSession* Find(int64_t sid);

 private:
  Stat stats_[OEM_FUNCTION_COUNT];

  CircularBuffer buffer_;

  uint64_t time_at_head_;
  uint64_t time_at_tail_;

  bool RequestSpace(uint8_t num_bytes);

  bool ReadNextEntryRealEndTime(uint64_t* output);

  bool DropLastEntry();

  // Read a variable length value. This is the read that matches
  // EntryWriter's WriteVLV.
  int ReadVLV(size_t offset, uint64_t* output) const;

  ProfilerSession(const ProfilerSession&);
  void operator=(const ProfilerSession&);

  static uint8_t GetByte(uint64_t value, size_t byte_index);

  static std::map<int64_t, ProfilerSession*> sessions_;
};

}  // namespace oemprofiler
}  // namespace wvcdm

#endif