/*
 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "webrtc/video/send_statistics_proxy.h"

#include <algorithm>
#include <cmath>
#include <map>

#include "webrtc/base/checks.h"
#include "webrtc/base/logging.h"
#include "webrtc/system_wrappers/include/critical_section_wrapper.h"
#include "webrtc/system_wrappers/include/metrics.h"

namespace webrtc {
namespace {
const float kEncodeTimeWeigthFactor = 0.5f;

// Used by histograms. Values of entries should not be changed.
enum HistogramCodecType {
  kVideoUnknown = 0,
  kVideoVp8 = 1,
  kVideoVp9 = 2,
  kVideoH264 = 3,
  kVideoMax = 64,
};

const char* GetUmaPrefix(VideoEncoderConfig::ContentType content_type) {
  switch (content_type) {
    case VideoEncoderConfig::ContentType::kRealtimeVideo:
      return "WebRTC.Video.";
    case VideoEncoderConfig::ContentType::kScreen:
      return "WebRTC.Video.Screenshare.";
  }
  RTC_NOTREACHED();
  return nullptr;
}

HistogramCodecType PayloadNameToHistogramCodecType(
    const std::string& payload_name) {
  if (payload_name == "VP8") {
    return kVideoVp8;
  } else if (payload_name == "VP9") {
    return kVideoVp9;
  } else if (payload_name == "H264") {
    return kVideoH264;
  } else {
    return kVideoUnknown;
  }
}

void UpdateCodecTypeHistogram(const std::string& payload_name) {
  RTC_HISTOGRAM_ENUMERATION("WebRTC.Video.Encoder.CodecType",
      PayloadNameToHistogramCodecType(payload_name), kVideoMax);
}
}  // namespace


const int SendStatisticsProxy::kStatsTimeoutMs = 5000;

SendStatisticsProxy::SendStatisticsProxy(
    Clock* clock,
    const VideoSendStream::Config& config,
    VideoEncoderConfig::ContentType content_type)
    : clock_(clock),
      config_(config),
      content_type_(content_type),
      last_sent_frame_timestamp_(0),
      encode_time_(kEncodeTimeWeigthFactor),
      uma_container_(new UmaSamplesContainer(GetUmaPrefix(content_type_))) {
  UpdateCodecTypeHistogram(config_.encoder_settings.payload_name);
}

SendStatisticsProxy::~SendStatisticsProxy() {}

SendStatisticsProxy::UmaSamplesContainer::UmaSamplesContainer(
    const char* prefix)
    : uma_prefix_(prefix),
      max_sent_width_per_timestamp_(0),
      max_sent_height_per_timestamp_(0),
      input_frame_rate_tracker_(100u, 10u),
      sent_frame_rate_tracker_(100u, 10u) {}

SendStatisticsProxy::UmaSamplesContainer::~UmaSamplesContainer() {
  UpdateHistograms();
}

void SendStatisticsProxy::UmaSamplesContainer::UpdateHistograms() {
  const int kMinRequiredSamples = 200;
  int in_width = input_width_counter_.Avg(kMinRequiredSamples);
  int in_height = input_height_counter_.Avg(kMinRequiredSamples);
  int in_fps = round(input_frame_rate_tracker_.ComputeTotalRate());
  if (in_width != -1) {
    RTC_HISTOGRAM_COUNTS_10000(uma_prefix_ + "InputWidthInPixels", in_width);
    RTC_HISTOGRAM_COUNTS_10000(uma_prefix_ + "InputHeightInPixels", in_height);
    RTC_HISTOGRAM_COUNTS_100(uma_prefix_ + "InputFramesPerSecond", in_fps);
  }
  int sent_width = sent_width_counter_.Avg(kMinRequiredSamples);
  int sent_height = sent_height_counter_.Avg(kMinRequiredSamples);
  int sent_fps = round(sent_frame_rate_tracker_.ComputeTotalRate());
  if (sent_width != -1) {
    RTC_HISTOGRAM_COUNTS_10000(uma_prefix_ + "SentWidthInPixels", sent_width);
    RTC_HISTOGRAM_COUNTS_10000(uma_prefix_ + "SentHeightInPixels", sent_height);
    RTC_HISTOGRAM_COUNTS_100(uma_prefix_ + "SentFramesPerSecond", sent_fps);
  }
  int encode_ms = encode_time_counter_.Avg(kMinRequiredSamples);
  if (encode_ms != -1)
    RTC_HISTOGRAM_COUNTS_1000(uma_prefix_ + "EncodeTimeInMs", encode_ms);

  int key_frames_permille = key_frame_counter_.Permille(kMinRequiredSamples);
  if (key_frames_permille != -1) {
    RTC_HISTOGRAM_COUNTS_1000(uma_prefix_ + "KeyFramesSentInPermille",
                              key_frames_permille);
  }
  int quality_limited =
      quality_limited_frame_counter_.Percent(kMinRequiredSamples);
  if (quality_limited != -1) {
    RTC_HISTOGRAM_PERCENTAGE(uma_prefix_ + "QualityLimitedResolutionInPercent",
                             quality_limited);
  }
  int downscales = quality_downscales_counter_.Avg(kMinRequiredSamples);
  if (downscales != -1) {
    RTC_HISTOGRAM_ENUMERATION(
        uma_prefix_ + "QualityLimitedResolutionDownscales", downscales, 20);
  }
  int bw_limited = bw_limited_frame_counter_.Percent(kMinRequiredSamples);
  if (bw_limited != -1) {
    RTC_HISTOGRAM_PERCENTAGE(
        uma_prefix_ + "BandwidthLimitedResolutionInPercent", bw_limited);
  }
  int num_disabled = bw_resolutions_disabled_counter_.Avg(kMinRequiredSamples);
  if (num_disabled != -1) {
    RTC_HISTOGRAM_ENUMERATION(
        uma_prefix_ + "BandwidthLimitedResolutionsDisabled", num_disabled, 10);
  }
  int delay_ms = delay_counter_.Avg(kMinRequiredSamples);
  if (delay_ms != -1)
    RTC_HISTOGRAM_COUNTS_100000(uma_prefix_ + "SendSideDelayInMs", delay_ms);

  int max_delay_ms = max_delay_counter_.Avg(kMinRequiredSamples);
  if (max_delay_ms != -1) {
    RTC_HISTOGRAM_COUNTS_100000(uma_prefix_ + "SendSideDelayMaxInMs",
                                max_delay_ms);
  }
}

void SendStatisticsProxy::SetContentType(
    VideoEncoderConfig::ContentType content_type) {
  rtc::CritScope lock(&crit_);
  if (content_type_ != content_type) {
    uma_container_->UpdateHistograms();
    uma_container_.reset(new UmaSamplesContainer(GetUmaPrefix(content_type)));
    content_type_ = content_type;
  }
}

void SendStatisticsProxy::OnEncoderImplementationName(
    const char* implementation_name) {
  rtc::CritScope lock(&crit_);
  stats_.encoder_implementation_name = implementation_name;
}

void SendStatisticsProxy::OnOutgoingRate(uint32_t framerate, uint32_t bitrate) {
  rtc::CritScope lock(&crit_);
  stats_.encode_frame_rate = framerate;
  stats_.media_bitrate_bps = bitrate;
}

void SendStatisticsProxy::CpuOveruseMetricsUpdated(
    const CpuOveruseMetrics& metrics) {
  rtc::CritScope lock(&crit_);
  stats_.encode_usage_percent = metrics.encode_usage_percent;
}

void SendStatisticsProxy::OnSuspendChange(bool is_suspended) {
  rtc::CritScope lock(&crit_);
  stats_.suspended = is_suspended;
}

VideoSendStream::Stats SendStatisticsProxy::GetStats() {
  rtc::CritScope lock(&crit_);
  PurgeOldStats();
  stats_.input_frame_rate =
      round(uma_container_->input_frame_rate_tracker_.ComputeRate());
  return stats_;
}

void SendStatisticsProxy::PurgeOldStats() {
  int64_t old_stats_ms = clock_->TimeInMilliseconds() - kStatsTimeoutMs;
  for (std::map<uint32_t, VideoSendStream::StreamStats>::iterator it =
           stats_.substreams.begin();
       it != stats_.substreams.end(); ++it) {
    uint32_t ssrc = it->first;
    if (update_times_[ssrc].resolution_update_ms <= old_stats_ms) {
      it->second.width = 0;
      it->second.height = 0;
    }
  }
}

VideoSendStream::StreamStats* SendStatisticsProxy::GetStatsEntry(
    uint32_t ssrc) {
  std::map<uint32_t, VideoSendStream::StreamStats>::iterator it =
      stats_.substreams.find(ssrc);
  if (it != stats_.substreams.end())
    return &it->second;

  if (std::find(config_.rtp.ssrcs.begin(), config_.rtp.ssrcs.end(), ssrc) ==
          config_.rtp.ssrcs.end() &&
      std::find(config_.rtp.rtx.ssrcs.begin(),
                config_.rtp.rtx.ssrcs.end(),
                ssrc) == config_.rtp.rtx.ssrcs.end()) {
    return nullptr;
  }

  return &stats_.substreams[ssrc];  // Insert new entry and return ptr.
}

void SendStatisticsProxy::OnInactiveSsrc(uint32_t ssrc) {
  rtc::CritScope lock(&crit_);
  VideoSendStream::StreamStats* stats = GetStatsEntry(ssrc);
  if (stats == nullptr)
    return;

  stats->total_bitrate_bps = 0;
  stats->retransmit_bitrate_bps = 0;
  stats->height = 0;
  stats->width = 0;
}

void SendStatisticsProxy::OnSetRates(uint32_t bitrate_bps, int framerate) {
  rtc::CritScope lock(&crit_);
  stats_.target_media_bitrate_bps = bitrate_bps;
}

void SendStatisticsProxy::OnSendEncodedImage(
    const EncodedImage& encoded_image,
    const RTPVideoHeader* rtp_video_header) {
  size_t simulcast_idx =
      rtp_video_header != nullptr ? rtp_video_header->simulcastIdx : 0;
  if (simulcast_idx >= config_.rtp.ssrcs.size()) {
    LOG(LS_ERROR) << "Encoded image outside simulcast range (" << simulcast_idx
                  << " >= " << config_.rtp.ssrcs.size() << ").";
    return;
  }
  uint32_t ssrc = config_.rtp.ssrcs[simulcast_idx];

  rtc::CritScope lock(&crit_);
  VideoSendStream::StreamStats* stats = GetStatsEntry(ssrc);
  if (stats == nullptr)
    return;

  stats->width = encoded_image._encodedWidth;
  stats->height = encoded_image._encodedHeight;
  update_times_[ssrc].resolution_update_ms = clock_->TimeInMilliseconds();

  uma_container_->key_frame_counter_.Add(encoded_image._frameType ==
                                         kVideoFrameKey);

  stats_.bw_limited_resolution =
      encoded_image.adapt_reason_.quality_resolution_downscales > 0 ||
      encoded_image.adapt_reason_.bw_resolutions_disabled > 0;

  if (encoded_image.adapt_reason_.quality_resolution_downscales != -1) {
    bool downscaled =
        encoded_image.adapt_reason_.quality_resolution_downscales > 0;
    uma_container_->quality_limited_frame_counter_.Add(downscaled);
    if (downscaled) {
      uma_container_->quality_downscales_counter_.Add(
          encoded_image.adapt_reason_.quality_resolution_downscales);
    }
  }
  if (encoded_image.adapt_reason_.bw_resolutions_disabled != -1) {
    bool bw_limited = encoded_image.adapt_reason_.bw_resolutions_disabled > 0;
    uma_container_->bw_limited_frame_counter_.Add(bw_limited);
    if (bw_limited) {
      uma_container_->bw_resolutions_disabled_counter_.Add(
          encoded_image.adapt_reason_.bw_resolutions_disabled);
    }
  }

  // TODO(asapersson): This is incorrect if simulcast layers are encoded on
  // different threads and there is no guarantee that one frame of all layers
  // are encoded before the next start.
  if (last_sent_frame_timestamp_ > 0 &&
      encoded_image._timeStamp != last_sent_frame_timestamp_) {
    uma_container_->sent_frame_rate_tracker_.AddSamples(1);
    uma_container_->sent_width_counter_.Add(
        uma_container_->max_sent_width_per_timestamp_);
    uma_container_->sent_height_counter_.Add(
        uma_container_->max_sent_height_per_timestamp_);
    uma_container_->max_sent_width_per_timestamp_ = 0;
    uma_container_->max_sent_height_per_timestamp_ = 0;
  }
  last_sent_frame_timestamp_ = encoded_image._timeStamp;
  uma_container_->max_sent_width_per_timestamp_ =
      std::max(uma_container_->max_sent_width_per_timestamp_,
               static_cast<int>(encoded_image._encodedWidth));
  uma_container_->max_sent_height_per_timestamp_ =
      std::max(uma_container_->max_sent_height_per_timestamp_,
               static_cast<int>(encoded_image._encodedHeight));
}

void SendStatisticsProxy::OnIncomingFrame(int width, int height) {
  rtc::CritScope lock(&crit_);
  uma_container_->input_frame_rate_tracker_.AddSamples(1);
  uma_container_->input_width_counter_.Add(width);
  uma_container_->input_height_counter_.Add(height);
}

void SendStatisticsProxy::OnEncodedFrame(int encode_time_ms) {
  rtc::CritScope lock(&crit_);
  uma_container_->encode_time_counter_.Add(encode_time_ms);
  encode_time_.Apply(1.0f, encode_time_ms);
  stats_.avg_encode_time_ms = round(encode_time_.filtered());
}

void SendStatisticsProxy::RtcpPacketTypesCounterUpdated(
    uint32_t ssrc,
    const RtcpPacketTypeCounter& packet_counter) {
  rtc::CritScope lock(&crit_);
  VideoSendStream::StreamStats* stats = GetStatsEntry(ssrc);
  if (stats == nullptr)
    return;

  stats->rtcp_packet_type_counts = packet_counter;
}

void SendStatisticsProxy::StatisticsUpdated(const RtcpStatistics& statistics,
                                            uint32_t ssrc) {
  rtc::CritScope lock(&crit_);
  VideoSendStream::StreamStats* stats = GetStatsEntry(ssrc);
  if (stats == nullptr)
    return;

  stats->rtcp_stats = statistics;
}

void SendStatisticsProxy::CNameChanged(const char* cname, uint32_t ssrc) {
}

void SendStatisticsProxy::DataCountersUpdated(
    const StreamDataCounters& counters,
    uint32_t ssrc) {
  rtc::CritScope lock(&crit_);
  VideoSendStream::StreamStats* stats = GetStatsEntry(ssrc);
  RTC_DCHECK(stats != nullptr)
      << "DataCountersUpdated reported for unknown ssrc: " << ssrc;

  stats->rtp_stats = counters;
}

void SendStatisticsProxy::Notify(const BitrateStatistics& total_stats,
                                 const BitrateStatistics& retransmit_stats,
                                 uint32_t ssrc) {
  rtc::CritScope lock(&crit_);
  VideoSendStream::StreamStats* stats = GetStatsEntry(ssrc);
  if (stats == nullptr)
    return;

  stats->total_bitrate_bps = total_stats.bitrate_bps;
  stats->retransmit_bitrate_bps = retransmit_stats.bitrate_bps;
}

void SendStatisticsProxy::FrameCountUpdated(const FrameCounts& frame_counts,
                                            uint32_t ssrc) {
  rtc::CritScope lock(&crit_);
  VideoSendStream::StreamStats* stats = GetStatsEntry(ssrc);
  if (stats == nullptr)
    return;

  stats->frame_counts = frame_counts;
}

void SendStatisticsProxy::SendSideDelayUpdated(int avg_delay_ms,
                                               int max_delay_ms,
                                               uint32_t ssrc) {
  rtc::CritScope lock(&crit_);
  VideoSendStream::StreamStats* stats = GetStatsEntry(ssrc);
  if (stats == nullptr)
    return;
  stats->avg_delay_ms = avg_delay_ms;
  stats->max_delay_ms = max_delay_ms;

  uma_container_->delay_counter_.Add(avg_delay_ms);
  uma_container_->max_delay_counter_.Add(max_delay_ms);
}

void SendStatisticsProxy::SampleCounter::Add(int sample) {
  sum += sample;
  ++num_samples;
}

int SendStatisticsProxy::SampleCounter::Avg(int min_required_samples) const {
  if (num_samples < min_required_samples || num_samples == 0)
    return -1;
  return (sum + (num_samples / 2)) / num_samples;
}

void SendStatisticsProxy::BoolSampleCounter::Add(bool sample) {
  if (sample)
    ++sum;
  ++num_samples;
}

int SendStatisticsProxy::BoolSampleCounter::Percent(
    int min_required_samples) const {
  return Fraction(min_required_samples, 100.0f);
}

int SendStatisticsProxy::BoolSampleCounter::Permille(
    int min_required_samples) const {
  return Fraction(min_required_samples, 1000.0f);
}

int SendStatisticsProxy::BoolSampleCounter::Fraction(
    int min_required_samples, float multiplier) const {
  if (num_samples < min_required_samples || num_samples == 0)
    return -1;
  return static_cast<int>((sum * multiplier / num_samples) + 0.5f);
}
}  // namespace webrtc