/*
 *  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.
 */

#ifndef WEBRTC_VIDEO_SEND_STATISTICS_PROXY_H_
#define WEBRTC_VIDEO_SEND_STATISTICS_PROXY_H_

#include <map>
#include <memory>
#include <string>
#include <vector>

#include "webrtc/base/criticalsection.h"
#include "webrtc/base/numerics/exp_filter.h"
#include "webrtc/base/ratetracker.h"
#include "webrtc/base/thread_annotations.h"
#include "webrtc/common_types.h"
#include "webrtc/modules/video_coding/include/video_codec_interface.h"
#include "webrtc/modules/video_coding/include/video_coding_defines.h"
#include "webrtc/system_wrappers/include/clock.h"
#include "webrtc/video/overuse_frame_detector.h"
#include "webrtc/video/report_block_stats.h"
#include "webrtc/video/stats_counter.h"
#include "webrtc/video/vie_encoder.h"
#include "webrtc/video_send_stream.h"

namespace webrtc {

class SendStatisticsProxy : public CpuOveruseMetricsObserver,
                            public RtcpStatisticsCallback,
                            public RtcpPacketTypeCounterObserver,
                            public StreamDataCountersCallback,
                            public BitrateStatisticsObserver,
                            public FrameCountObserver,
                            public SendSideDelayObserver {
 public:
  static const int kStatsTimeoutMs;
  // Number of required samples to be collected before a metric is added
  // to a rtc histogram.
  static const int kMinRequiredMetricsSamples = 200;

  SendStatisticsProxy(Clock* clock,
                      const VideoSendStream::Config& config,
                      VideoEncoderConfig::ContentType content_type);
  virtual ~SendStatisticsProxy();

  virtual VideoSendStream::Stats GetStats();

  virtual void OnSendEncodedImage(const EncodedImage& encoded_image,
                                  const CodecSpecificInfo* codec_info);
  // Used to update incoming frame rate.
  void OnIncomingFrame(int width, int height);

  void OnCpuRestrictedResolutionChanged(bool cpu_restricted_resolution);
  void OnQualityRestrictedResolutionChanged(int num_quality_downscales);
  void SetCpuScalingStats(int num_cpu_downscales);  // -1: disabled.
  void SetQualityScalingStats(int num_quality_downscales);  // -1: disabled.

  void OnEncoderStatsUpdate(uint32_t framerate, uint32_t bitrate);
  void OnSuspendChange(bool is_suspended);
  void OnInactiveSsrc(uint32_t ssrc);

  // Used to indicate change in content type, which may require a change in
  // how stats are collected and set the configured preferred media bitrate.
  void OnEncoderReconfigured(const VideoEncoderConfig& encoder_config,
                             uint32_t preferred_bitrate_bps);

  // Used to update the encoder target rate.
  void OnSetEncoderTargetRate(uint32_t bitrate_bps);

  // Implements CpuOveruseMetricsObserver.
  void OnEncodedFrameTimeMeasured(int encode_time_ms,
                                  const CpuOveruseMetrics& metrics) override;

  int GetSendFrameRate() const;

 protected:
  // From RtcpStatisticsCallback.
  void StatisticsUpdated(const RtcpStatistics& statistics,
                         uint32_t ssrc) override;
  void CNameChanged(const char* cname, uint32_t ssrc) override;
  // From RtcpPacketTypeCounterObserver.
  void RtcpPacketTypesCounterUpdated(
      uint32_t ssrc,
      const RtcpPacketTypeCounter& packet_counter) override;
  // From StreamDataCountersCallback.
  void DataCountersUpdated(const StreamDataCounters& counters,
                           uint32_t ssrc) override;

  // From BitrateStatisticsObserver.
  void Notify(uint32_t total_bitrate_bps,
              uint32_t retransmit_bitrate_bps,
              uint32_t ssrc) override;

  // From FrameCountObserver.
  void FrameCountUpdated(const FrameCounts& frame_counts,
                         uint32_t ssrc) override;

  void SendSideDelayUpdated(int avg_delay_ms,
                            int max_delay_ms,
                            uint32_t ssrc) override;

 private:
  class SampleCounter {
   public:
    SampleCounter() : sum(0), num_samples(0) {}
    ~SampleCounter() {}
    void Add(int sample);
    int Avg(int64_t min_required_samples) const;

   private:
    int64_t sum;
    int64_t num_samples;
  };
  class BoolSampleCounter {
   public:
    BoolSampleCounter() : sum(0), num_samples(0) {}
    ~BoolSampleCounter() {}
    void Add(bool sample);
    void Add(bool sample, int64_t count);
    int Percent(int64_t min_required_samples) const;
    int Permille(int64_t min_required_samples) const;

   private:
    int Fraction(int64_t min_required_samples, float multiplier) const;
    int64_t sum;
    int64_t num_samples;
  };
  struct StatsUpdateTimes {
    StatsUpdateTimes() : resolution_update_ms(0), bitrate_update_ms(0) {}
    int64_t resolution_update_ms;
    int64_t bitrate_update_ms;
  };
  struct TargetRateUpdates {
    TargetRateUpdates()
        : pause_resume_events(0), last_paused_or_resumed(false), last_ms(-1) {}
    int pause_resume_events;
    bool last_paused_or_resumed;
    int64_t last_ms;
  };
  struct StatsTimer {
    void Start(int64_t now_ms);
    void Stop(int64_t now_ms);
    void Restart(int64_t now_ms);
    int64_t start_ms = -1;
    int64_t total_ms = 0;
  };
  struct QpCounters {
    SampleCounter vp8;   // QP range: 0-127.
    SampleCounter vp9;   // QP range: 0-255.
    SampleCounter h264;  // QP range: 0-51.
  };
  void PurgeOldStats() EXCLUSIVE_LOCKS_REQUIRED(crit_);
  VideoSendStream::StreamStats* GetStatsEntry(uint32_t ssrc)
      EXCLUSIVE_LOCKS_REQUIRED(crit_);

  Clock* const clock_;
  const std::string payload_name_;
  const VideoSendStream::Config::Rtp rtp_config_;
  rtc::CriticalSection crit_;
  VideoEncoderConfig::ContentType content_type_ GUARDED_BY(crit_);
  const int64_t start_ms_;
  VideoSendStream::Stats stats_ GUARDED_BY(crit_);
  uint32_t last_sent_frame_timestamp_ GUARDED_BY(crit_);
  std::map<uint32_t, StatsUpdateTimes> update_times_ GUARDED_BY(crit_);
  rtc::ExpFilter encode_time_ GUARDED_BY(crit_);
  int quality_downscales_ GUARDED_BY(crit_);
  int cpu_downscales_ GUARDED_BY(crit_);

  // Contains stats used for UMA histograms. These stats will be reset if
  // content type changes between real-time video and screenshare, since these
  // will be reported separately.
  struct UmaSamplesContainer {
    UmaSamplesContainer(const char* prefix,
                        const VideoSendStream::Stats& start_stats,
                        Clock* clock);
    ~UmaSamplesContainer();

    void UpdateHistograms(const VideoSendStream::Config::Rtp& rtp_config,
                          const VideoSendStream::Stats& current_stats);

    void InitializeBitrateCounters(const VideoSendStream::Stats& stats);

    const std::string uma_prefix_;
    Clock* const clock_;
    int max_sent_width_per_timestamp_;
    int max_sent_height_per_timestamp_;
    SampleCounter input_width_counter_;
    SampleCounter input_height_counter_;
    SampleCounter sent_width_counter_;
    SampleCounter sent_height_counter_;
    SampleCounter encode_time_counter_;
    BoolSampleCounter key_frame_counter_;
    BoolSampleCounter quality_limited_frame_counter_;
    SampleCounter quality_downscales_counter_;
    BoolSampleCounter cpu_limited_frame_counter_;
    BoolSampleCounter bw_limited_frame_counter_;
    SampleCounter bw_resolutions_disabled_counter_;
    SampleCounter delay_counter_;
    SampleCounter max_delay_counter_;
    rtc::RateTracker input_frame_rate_tracker_;
    RateCounter input_fps_counter_;
    RateCounter sent_fps_counter_;
    RateAccCounter total_byte_counter_;
    RateAccCounter media_byte_counter_;
    RateAccCounter rtx_byte_counter_;
    RateAccCounter padding_byte_counter_;
    RateAccCounter retransmit_byte_counter_;
    RateAccCounter fec_byte_counter_;
    int64_t first_rtcp_stats_time_ms_;
    int64_t first_rtp_stats_time_ms_;
    StatsTimer cpu_scaling_timer_;
    StatsTimer quality_scaling_timer_;
    BoolSampleCounter paused_time_counter_;
    TargetRateUpdates target_rate_updates_;
    ReportBlockStats report_block_stats_;
    const VideoSendStream::Stats start_stats_;

    std::map<int, QpCounters>
        qp_counters_;  // QP counters mapped by spatial idx.
  };

  std::unique_ptr<UmaSamplesContainer> uma_container_ GUARDED_BY(crit_);
};

}  // namespace webrtc
#endif  // WEBRTC_VIDEO_SEND_STATISTICS_PROXY_H_