/*
 * Copyright 2011-2018 Blender Foundation
 *
 * 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 "render/stats.h"
#include "render/object.h"
#include "util/util_algorithm.h"
#include "util/util_foreach.h"
#include "util/util_string.h"

CCL_NAMESPACE_BEGIN

static int kIndentNumSpaces = 2;

/* Named size entry. */

namespace {

bool namedSizeEntryComparator(const NamedSizeEntry &a, const NamedSizeEntry &b)
{
  /* We sort in descending order. */
  return a.size > b.size;
}

bool namedTimeSampleEntryComparator(const NamedNestedSampleStats &a,
                                    const NamedNestedSampleStats &b)
{
  return a.sum_samples > b.sum_samples;
}

bool namedSampleCountPairComparator(const NamedSampleCountPair &a, const NamedSampleCountPair &b)
{
  return a.samples > b.samples;
}

}  // namespace

NamedSizeEntry::NamedSizeEntry() : name(""), size(0)
{
}

NamedSizeEntry::NamedSizeEntry(const string &name, size_t size) : name(name), size(size)
{
}

/* Named size statistics. */

NamedSizeStats::NamedSizeStats() : total_size(0)
{
}

void NamedSizeStats::add_entry(const NamedSizeEntry &entry)
{
  total_size += entry.size;
  entries.push_back(entry);
}

string NamedSizeStats::full_report(int indent_level)
{
  const string indent(indent_level * kIndentNumSpaces, ' ');
  const string double_indent = indent + indent;
  string result = "";
  result += string_printf("%sTotal memory: %s (%s)\n",
                          indent.c_str(),
                          string_human_readable_size(total_size).c_str(),
                          string_human_readable_number(total_size).c_str());
  sort(entries.begin(), entries.end(), namedSizeEntryComparator);
  foreach (const NamedSizeEntry &entry, entries) {
    result += string_printf("%s%-32s %s (%s)\n",
                            double_indent.c_str(),
                            entry.name.c_str(),
                            string_human_readable_size(entry.size).c_str(),
                            string_human_readable_number(entry.size).c_str());
  }
  return result;
}

/* Named time sample statistics. */

NamedNestedSampleStats::NamedNestedSampleStats() : name(""), self_samples(0), sum_samples(0)
{
}

NamedNestedSampleStats::NamedNestedSampleStats(const string &name, uint64_t samples)
    : name(name), self_samples(samples), sum_samples(samples)
{
}

NamedNestedSampleStats &NamedNestedSampleStats::add_entry(const string &name_, uint64_t samples_)
{
  entries.push_back(NamedNestedSampleStats(name_, samples_));
  return entries[entries.size() - 1];
}

void NamedNestedSampleStats::update_sum()
{
  sum_samples = self_samples;
  foreach (NamedNestedSampleStats &entry, entries) {
    entry.update_sum();
    sum_samples += entry.sum_samples;
  }
}

string NamedNestedSampleStats::full_report(int indent_level, uint64_t total_samples)
{
  update_sum();

  if (total_samples == 0) {
    total_samples = sum_samples;
  }

  const string indent(indent_level * kIndentNumSpaces, ' ');

  const double sum_percent = 100 * ((double)sum_samples) / total_samples;
  const double sum_seconds = sum_samples * 0.001;
  const double self_percent = 100 * ((double)self_samples) / total_samples;
  const double self_seconds = self_samples * 0.001;
  string info = string_printf("%-32s: Total %3.2f%% (%.2fs), Self %3.2f%% (%.2fs)\n",
                              name.c_str(),
                              sum_percent,
                              sum_seconds,
                              self_percent,
                              self_seconds);
  string result = indent + info;

  sort(entries.begin(), entries.end(), namedTimeSampleEntryComparator);
  foreach (NamedNestedSampleStats &entry, entries) {
    result += entry.full_report(indent_level + 1, total_samples);
  }
  return result;
}

/* Named sample count pairs. */

NamedSampleCountPair::NamedSampleCountPair(const ustring &name, uint64_t samples, uint64_t hits)
    : name(name), samples(samples), hits(hits)
{
}

NamedSampleCountStats::NamedSampleCountStats()
{
}

void NamedSampleCountStats::add(const ustring &name, uint64_t samples, uint64_t hits)
{
  entry_map::iterator entry = entries.find(name);
  if (entry != entries.end()) {
    entry->second.samples += samples;
    entry->second.hits += hits;
    return;
  }
  entries.emplace(name, NamedSampleCountPair(name, samples, hits));
}

string NamedSampleCountStats::full_report(int indent_level)
{
  const string indent(indent_level * kIndentNumSpaces, ' ');

  vector<NamedSampleCountPair> sorted_entries;
  sorted_entries.reserve(entries.size());

  uint64_t total_hits = 0, total_samples = 0;
  foreach (entry_map::const_reference entry, entries) {
    const NamedSampleCountPair &pair = entry.second;

    total_hits += pair.hits;
    total_samples += pair.samples;

    sorted_entries.push_back(pair);
  }
  const double avg_samples_per_hit = ((double)total_samples) / total_hits;

  sort(sorted_entries.begin(), sorted_entries.end(), namedSampleCountPairComparator);

  string result = "";
  foreach (const NamedSampleCountPair &entry, sorted_entries) {
    const double seconds = entry.samples * 0.001;
    const double relative = ((double)entry.samples) / (entry.hits * avg_samples_per_hit);

    result += indent +
              string_printf(
                  "%-32s: %.2fs (Relative cost: %.2f)\n", entry.name.c_str(), seconds, relative);
  }
  return result;
}

/* Mesh statistics. */

MeshStats::MeshStats()
{
}

string MeshStats::full_report(int indent_level)
{
  const string indent(indent_level * kIndentNumSpaces, ' ');
  string result = "";
  result += indent + "Geometry:\n" + geometry.full_report(indent_level + 1);
  return result;
}

/* Image statistics. */

ImageStats::ImageStats()
{
}

string ImageStats::full_report(int indent_level)
{
  const string indent(indent_level * kIndentNumSpaces, ' ');
  string result = "";
  result += indent + "Textures:\n" + textures.full_report(indent_level + 1);
  return result;
}

/* Overall statistics. */

RenderStats::RenderStats()
{
  has_profiling = false;
}

void RenderStats::collect_profiling(Scene *scene, Profiler &prof)
{
  has_profiling = true;

  kernel = NamedNestedSampleStats("Total render time", prof.get_event(PROFILING_UNKNOWN));

  kernel.add_entry("Ray setup", prof.get_event(PROFILING_RAY_SETUP));
  kernel.add_entry("Result writing", prof.get_event(PROFILING_WRITE_RESULT));

  NamedNestedSampleStats &integrator = kernel.add_entry("Path integration",
                                                        prof.get_event(PROFILING_PATH_INTEGRATE));
  integrator.add_entry("Scene intersection", prof.get_event(PROFILING_SCENE_INTERSECT));
  integrator.add_entry("Indirect emission", prof.get_event(PROFILING_INDIRECT_EMISSION));
  integrator.add_entry("Volumes", prof.get_event(PROFILING_VOLUME));

  NamedNestedSampleStats &shading = integrator.add_entry("Shading", 0);
  shading.add_entry("Shader Setup", prof.get_event(PROFILING_SHADER_SETUP));
  shading.add_entry("Shader Eval", prof.get_event(PROFILING_SHADER_EVAL));
  shading.add_entry("Shader Apply", prof.get_event(PROFILING_SHADER_APPLY));
  shading.add_entry("Ambient Occlusion", prof.get_event(PROFILING_AO));
  shading.add_entry("Subsurface", prof.get_event(PROFILING_SUBSURFACE));

  integrator.add_entry("Connect Light", prof.get_event(PROFILING_CONNECT_LIGHT));
  integrator.add_entry("Surface Bounce", prof.get_event(PROFILING_SURFACE_BOUNCE));

  NamedNestedSampleStats &intersection = kernel.add_entry("Intersection", 0);
  intersection.add_entry("Full Intersection", prof.get_event(PROFILING_INTERSECT));
  intersection.add_entry("Local Intersection", prof.get_event(PROFILING_INTERSECT_LOCAL));
  intersection.add_entry("Shadow All Intersection",
                         prof.get_event(PROFILING_INTERSECT_SHADOW_ALL));
  intersection.add_entry("Volume Intersection", prof.get_event(PROFILING_INTERSECT_VOLUME));
  intersection.add_entry("Volume All Intersection",
                         prof.get_event(PROFILING_INTERSECT_VOLUME_ALL));

  NamedNestedSampleStats &closure = kernel.add_entry("Closures", 0);
  closure.add_entry("Surface Closure Evaluation", prof.get_event(PROFILING_CLOSURE_EVAL));
  closure.add_entry("Surface Closure Sampling", prof.get_event(PROFILING_CLOSURE_SAMPLE));
  closure.add_entry("Volume Closure Evaluation", prof.get_event(PROFILING_CLOSURE_VOLUME_EVAL));
  closure.add_entry("Volume Closure Sampling", prof.get_event(PROFILING_CLOSURE_VOLUME_SAMPLE));

  NamedNestedSampleStats &denoising = kernel.add_entry("Denoising",
                                                       prof.get_event(PROFILING_DENOISING));
  denoising.add_entry("Construct Transform",
                      prof.get_event(PROFILING_DENOISING_CONSTRUCT_TRANSFORM));
  denoising.add_entry("Reconstruct", prof.get_event(PROFILING_DENOISING_RECONSTRUCT));

  NamedNestedSampleStats &prefilter = denoising.add_entry("Prefiltering", 0);
  prefilter.add_entry("Divide Shadow", prof.get_event(PROFILING_DENOISING_DIVIDE_SHADOW));
  prefilter.add_entry("Non-Local means", prof.get_event(PROFILING_DENOISING_NON_LOCAL_MEANS));
  prefilter.add_entry("Get Feature", prof.get_event(PROFILING_DENOISING_GET_FEATURE));
  prefilter.add_entry("Detect Outliers", prof.get_event(PROFILING_DENOISING_DETECT_OUTLIERS));
  prefilter.add_entry("Combine Halves", prof.get_event(PROFILING_DENOISING_COMBINE_HALVES));

  shaders.entries.clear();
  foreach (Shader *shader, scene->shaders) {
    uint64_t samples, hits;
    if (prof.get_shader(shader->id, samples, hits)) {
      shaders.add(shader->name, samples, hits);
    }
  }

  objects.entries.clear();
  foreach (Object *object, scene->objects) {
    uint64_t samples, hits;
    if (prof.get_object(object->get_device_index(), samples, hits)) {
      objects.add(object->name, samples, hits);
    }
  }
}

string RenderStats::full_report()
{
  string result = "";
  result += "Mesh statistics:\n" + mesh.full_report(1);
  result += "Image statistics:\n" + image.full_report(1);
  if (has_profiling) {
    result += "Kernel statistics:\n" + kernel.full_report(1);
    result += "Shader statistics:\n" + shaders.full_report(1);
    result += "Object statistics:\n" + objects.full_report(1);
  }
  else {
    result += "Profiling information not available (only works with CPU rendering)";
  }
  return result;
}

CCL_NAMESPACE_END