/*
 * Copyright (c) 2014-2021, NVIDIA CORPORATION.  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.
 *
 * SPDX-FileCopyrightText: Copyright (c) 2014-2021 NVIDIA CORPORATION
 * SPDX-License-Identifier: Apache-2.0
 */


#include "profiler.hpp"

#include <assert.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>


//////////////////////////////////////////////////////////////////////////

namespace nvh {

const uint32_t Profiler::CONFIG_DELAY;
const uint32_t Profiler::FRAME_DELAY;
const uint32_t Profiler::START_SECTIONS;
const uint32_t Profiler::MAX_NUM_AVERAGE;

Profiler::Profiler(Profiler* master)
{
  m_data = master ? master->m_data : std::shared_ptr<Data>(new Data);
  grow(START_SECTIONS);
}

Profiler::Profiler(uint32_t startSections)
{
  m_data = std::shared_ptr<Data>(new Data);
  grow(startSections);
}

void Profiler::setAveragingSize(uint32_t num)
{
  assert(num <= MAX_NUM_AVERAGE);
  m_data->numAveraging = num;

  for(size_t i = 0; i < m_data->entries.size(); i++)
  {
    m_data->entries[i].cpuTime.init(num);
    m_data->entries[i].gpuTime.init(num);
  }
  m_data->cpuTime.init(num);
}

void Profiler::beginFrame()
{
  m_data->level       = 0;
  m_data->nextSection = 0;
  m_data->frameSections.clear();

  m_data->cpuCurrentTime = -m_clock.getMicroSeconds();
}

void Profiler::endFrame()
{
  assert(m_data->level == 0);

  m_data->cpuCurrentTime += m_clock.getMicroSeconds();

  if(!m_data->frameSections.empty() && ((uint32_t)m_data->frameSections.size() != m_data->numLastEntries))
  {
    m_data->numLastEntries  = (uint32_t)m_data->frameSections.size();
    m_data->numLastSections = m_data->frameSections.back() + 1;
    m_data->resetDelay      = CONFIG_DELAY;
  }

  if(m_data->resetDelay)
  {
    m_data->resetDelay--;
    for(uint32_t i = 0; i < m_data->entries.size(); i++)
    {
      Entry& entry = m_data->entries[i];
      if(entry.level != LEVEL_SINGLESHOT)
      {
        entry.numTimes = 0;
        entry.cpuTime.reset();
        entry.gpuTime.reset();
      }
    }
    m_data->cpuTime.reset();
    m_data->numFrames = 0;
  }

  if(m_data->numFrames > FRAME_DELAY)
  {
    for(uint32_t i : m_data->frameSections)
    {
      Entry& entry = m_data->entries[i];

      if(entry.splitter)
        continue;

      uint32_t queryFrame = (m_data->numFrames + 1) % FRAME_DELAY;
      bool     available  = entry.api.empty() || entry.gpuTimeProvider(i, queryFrame, entry.gpuTimes[queryFrame]);

      if(available)
      {
        entry.cpuTime.add(entry.cpuTimes[queryFrame]);
        entry.gpuTime.add(entry.gpuTimes[queryFrame]);
        entry.numTimes++;
      }
    }

    for(uint32_t i : m_data->singleSections)
    {
      Entry&   entry      = m_data->entries[i];
      uint32_t queryFrame = entry.subFrame;

      // query once
      bool available = entry.cpuTime.numValid == 0
                       && (entry.api.empty() || entry.gpuTimeProvider(i, queryFrame, entry.gpuTimes[queryFrame]));

      if(available)
      {
        entry.cpuTime.add(entry.cpuTimes[queryFrame]);
        entry.gpuTime.add(entry.gpuTimes[queryFrame]);
        entry.numTimes++;
      }
    }

    m_data->cpuTime.add(m_data->cpuCurrentTime);
  }

  m_data->numFrames++;
}


void Profiler::grow(uint32_t newsize)
{
  size_t oldsize = m_data->entries.size();

  if(oldsize == newsize)
  {
    return;
  }

  m_data->entries.resize(newsize);

  for(size_t i = oldsize; i < newsize; i++)
  {
    m_data->entries[i].cpuTime.init(m_data->numAveraging);
    m_data->entries[i].gpuTime.init(m_data->numAveraging);
  }
}

void Profiler::clear()
{
  m_data->entries.clear();
  m_data->singleSections.clear();
}

void Profiler::reset(uint32_t delay)
{
  m_data->resetDelay = delay;
}

static std::string format(const char* msg, ...)
{
  std::size_t const STRING_BUFFER(8192);
  char              text[STRING_BUFFER];
  va_list           list;

  if(msg == 0)
    return std::string();

  va_start(list, msg);
#ifdef _WIN32
  vsprintf_s(text, msg, list);
#else  // #ifdef _WIN32
  vsprintf(text, msg, list);
#endif
  va_end(list);

  return std::string(text);
}

bool Profiler::getTimerInfo(uint32_t i, TimerInfo& info)
{
  Entry& entry = m_data->entries[i];

  if(!entry.numTimes || entry.accumulated)
  {
    return false;
  }

  info.gpu.average     = entry.gpuTime.getAveraged();
  info.cpu.average     = entry.cpuTime.getAveraged();
  info.cpu.absMinValue = entry.cpuTime.absMinValue;
  info.cpu.absMaxValue = entry.cpuTime.absMaxValue;
  info.gpu.absMinValue = entry.gpuTime.absMinValue;
  info.gpu.absMaxValue = entry.gpuTime.absMaxValue;
  bool found           = false;
  for(uint32_t n = i + 1; n < m_data->numLastSections; n++)
  {
    Entry& otherentry = m_data->entries[n];
    if(otherentry.name == entry.name && otherentry.level == entry.level && otherentry.api == entry.api && !otherentry.accumulated)
    {
      found = true;
      info.gpu.average += otherentry.gpuTime.getAveraged();
      info.cpu.average += otherentry.cpuTime.getAveraged();
      info.cpu.absMinValue += entry.cpuTime.absMinValue;
      info.cpu.absMaxValue += entry.cpuTime.absMaxValue;
      info.gpu.absMinValue += entry.gpuTime.absMinValue;
      info.gpu.absMaxValue += entry.gpuTime.absMaxValue;
      otherentry.accumulated = true;
    }

    if(otherentry.splitter && otherentry.level <= entry.level)
      break;
  }

  info.accumulated = found;
  info.numAveraged = entry.cpuTime.numValid;

  return true;
}

bool Profiler::getTimerInfo(const char* name, TimerInfo& info)
{
  if(name == nullptr)
  {
    info = TimerInfo();
    if(!m_data->cpuTime.numValid)
    {
      return false;
    }
    info.cpu.average     = m_data->cpuTime.getAveraged();
    info.cpu.absMaxValue = m_data->cpuTime.absMaxValue;
    info.cpu.absMinValue = m_data->cpuTime.absMinValue;
    info.numAveraged     = m_data->cpuTime.numValid;

    return true;
  }

  for(uint32_t i = 0; i < m_data->numLastSections; i++)
  {
    Entry& entry = m_data->entries[i];

    entry.accumulated = false;
  }

  for(uint32_t i = 0; i < (uint32_t)m_data->entries.size(); i++)
  {
    Entry& entry = m_data->entries[i];

    if(entry.name.empty())
      continue;

    if(name != entry.name)
      continue;

    return getTimerInfo(i, info);
  }

  return false;
}

void Profiler::print(std::string& stats)
{
  stats.clear();

  for(uint32_t i = 0; i < m_data->numLastSections; i++)
  {
    Entry& entry      = m_data->entries[i];
    entry.accumulated = false;
  }

  printf("Timer null;\t N/A %6d; CPU %6d;\n", 0, (uint32_t)m_data->cpuTime.getAveraged());

  for(uint32_t i = 0; i < m_data->numLastSections; i++)
  {
    static const char* spaces = "        ";  // 8
    Entry&             entry  = m_data->entries[i];

    if(entry.level == LEVEL_SINGLESHOT)
      continue;

    uint32_t level = 7 - (entry.level > 7 ? 7 : entry.level);

    TimerInfo info;
    if(!getTimerInfo(i, info))
      continue;

    const char* gpuname   = !entry.api.empty() ? entry.api.c_str() : "N/A";
    const char* entryname = !entry.name.empty() ? entry.name.c_str() : "N/A";

    if(info.accumulated)
    {
      stats += format("%sTimer %s;\t %s %6d; CPU %6d; (microseconds, accumulated loop)\n", &spaces[level], entryname,
                      gpuname, (uint32_t)(info.gpu.average), (uint32_t)(info.cpu.average));
    }
    else
    {
      stats += format("%sTimer %s;\t %s %6d; CPU %6d; (microseconds, avg %d)\n", &spaces[level], entryname, gpuname,
                      (uint32_t)(info.gpu.average), (uint32_t)(info.cpu.average), (uint32_t)entry.cpuTime.numValid);
    }
  }
}

uint32_t Profiler::getTotalFrames() const
{
  return m_data->numFrames;
}

void Profiler::accumulationSplit()
{
  SectionID sec = getSectionID(false, nullptr);
  if(sec >= m_data->entries.size())
  {
    grow((uint32_t)(m_data->entries.size() * 2));
  }

  m_data->entries[sec].level    = m_data->level;
  m_data->entries[sec].splitter = true;
}

Profiler::SectionID Profiler::getSectionID(bool singleShot, const char* name)
{
  uint32_t numEntries = (uint32_t)m_data->entries.size();

  if(singleShot)
  {
    // find empty slot or with same name
    for(uint32_t i = 0; i < numEntries; i++)
    {
      Entry& entry = m_data->entries[i];
      if(entry.name == name || entry.name.empty())
      {
        m_data->singleSections.push_back(i);
        return i;
      }
    }
    m_data->singleSections.push_back(numEntries);
    return numEntries;
  }
  else
  {
    // find non-single shot slot
    while(m_data->nextSection < numEntries && m_data->entries[m_data->nextSection].level == LEVEL_SINGLESHOT)
    {
      m_data->nextSection++;
    }

    m_data->frameSections.push_back(m_data->nextSection);
    return m_data->nextSection++;
  }
}

Profiler::SectionID Profiler::beginSection(const char* name, const char* api, gpuTimeProvider_fn gpuTimeProvider, bool singleShot)
{
  uint32_t  subFrame = m_data->numFrames % FRAME_DELAY;
  SectionID sec      = getSectionID(singleShot, name);

  if(sec >= m_data->entries.size())
  {
    grow((uint32_t)(m_data->entries.size() * 2));
  }

  Entry&   entry = m_data->entries[sec];
  uint32_t level = singleShot ? LEVEL_SINGLESHOT : (m_data->level++);

  if(entry.name != name || entry.api != api || entry.level != level)
  {
    entry.name = name;
    entry.api  = api;

    if(!singleShot)
    {
      m_data->resetDelay = CONFIG_DELAY;
    }
  }

  entry.subFrame        = subFrame;
  entry.level           = level;
  entry.splitter        = false;
  entry.gpuTimeProvider = gpuTimeProvider;

#ifdef NVP_SUPPORTS_NVTOOLSEXT
  {
    nvtxEventAttributes_t eventAttrib = {0};
    eventAttrib.version               = NVTX_VERSION;
    eventAttrib.size                  = NVTX_EVENT_ATTRIB_STRUCT_SIZE;
    eventAttrib.colorType             = NVTX_COLOR_ARGB;

    unsigned char color[4];
    color[0] = 255;
    color[1] = 0;
    color[2] = sec % 2 ? 127 : 255;
    color[3] = 255;

    color[2] -= level * 16;
    color[3] -= level * 16;

    eventAttrib.color         = *(uint32_t*)(color);
    eventAttrib.messageType   = NVTX_MESSAGE_TYPE_ASCII;
    eventAttrib.message.ascii = name;
    nvtxRangePushEx(&eventAttrib);
  }
#endif

  entry.cpuTimes[subFrame] = -getMicroSeconds();
  entry.gpuTimes[subFrame] = 0;

  if(singleShot)
  {
    entry.cpuTime.init(1);
    entry.gpuTime.init(1);
  }

  return sec;
}

void Profiler::endSection(SectionID sec)
{
  Entry& entry = m_data->entries[sec];

  entry.cpuTimes[entry.subFrame] += getMicroSeconds();

#ifdef NVP_SUPPORTS_NVTOOLSEXT
  nvtxRangePop();
#endif

  if(entry.level != LEVEL_SINGLESHOT)
  {
    m_data->level--;
  }
}

Profiler::Clock::Clock()
{
  m_init = std::chrono::high_resolution_clock::now();
}

double Profiler::Clock::getMicroSeconds() const
{
  return double(std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now() - m_init).count())
         / double(1000);
}
}  // namespace nvh