/*
 *  Copyright (c) 2019 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 VIDEO_FRAME_ENCODE_METADATA_WRITER_H_
#define VIDEO_FRAME_ENCODE_METADATA_WRITER_H_

#include <cstddef>
#include <cstdint>
#include <list>
#include <optional>
#include <vector>

#include "api/environment/environment.h"
#include "api/rtp_packet_infos.h"
#include "api/video/color_space.h"
#include "api/video/encoded_image.h"
#include "api/video/video_bitrate_allocation.h"
#include "api/video/video_frame.h"
#include "api/video/video_rotation.h"
#include "api/video_codecs/video_codec.h"
#include "api/video_codecs/video_encoder.h"
#include "modules/video_coding/include/video_codec_interface.h"
#include "rtc_base/synchronization/mutex.h"
#include "rtc_base/thread_annotations.h"

namespace webrtc {

class FrameEncodeMetadataWriter {
 public:
  FrameEncodeMetadataWriter(const Environment& env,
                            EncodedImageCallback* frame_drop_callback);
  ~FrameEncodeMetadataWriter();

  void OnEncoderInit(const VideoCodec& codec);
  void OnSetRates(const VideoBitrateAllocation& bitrate_allocation,
                  uint32_t framerate_fps);

  void OnEncodeStarted(const VideoFrame& frame);

  void FillMetadataAndTimingInfo(size_t simulcast_svc_idx,
                                 EncodedImage* encoded_image);

  void UpdateBitstream(const CodecSpecificInfo* codec_specific_info,
                       EncodedImage* encoded_image);

  void OnFrameDropped(uint32_t rtp_timestamp,
                      int spatial_id,
                      bool is_end_of_temporal_unit);

  void Reset();

 private:
  struct DropNotification {
    uint32_t rtp_timestamp;
    int spatial_id;
    bool is_end_of_temporal_unit;
  };

  // For non-internal-source encoders, returns encode started time and fixes
  // capture timestamp for the frame, if corrupted by the encoder.
  std::optional<int64_t> ExtractEncodeStartTimeAndFillMetadata(
      size_t simulcast_svc_idx,
      EncodedImage* encoded_image,
      std::vector<DropNotification>& drop_notifications)
      RTC_EXCLUSIVE_LOCKS_REQUIRED(lock_);
  void DropOldOrEqualFrames(uint32_t rtp_timestamp,
                            int spatial_id_to_skip,
                            std::vector<DropNotification>& drop_notifications)
      RTC_EXCLUSIVE_LOCKS_REQUIRED(lock_);
  // Returns true if any spatial layer contains a pending frame with the given
  // RTP timestamp.
  bool IsFrameWithRtpTimestampPending(uint32_t rtp_timestamp)
      RTC_EXCLUSIVE_LOCKS_REQUIRED(lock_);

  struct FrameMetadata {
    uint32_t rtp_timestamp;
    int64_t encode_start_time_ms;
    int64_t ntp_time_ms = 0;
    int64_t timestamp_us = 0;
    VideoRotation rotation = kVideoRotation_0;
    std::optional<ColorSpace> color_space;
    bool is_steady_state_refresh_frame = false;
    RtpPacketInfos packet_infos;
  };
  struct TimingFramesLayerInfo {
    TimingFramesLayerInfo();
    ~TimingFramesLayerInfo();
    size_t target_bitrate_bytes_per_sec = 0;
    std::list<FrameMetadata> frames;
  };

  const Environment env_;
  Mutex lock_;
  EncodedImageCallback* const frame_drop_callback_;
  VideoCodec codec_settings_ RTC_GUARDED_BY(&lock_);
  uint32_t framerate_fps_ RTC_GUARDED_BY(&lock_);

  size_t num_spatial_layers_ RTC_GUARDED_BY(&lock_);
  // Separate instance for each simulcast stream or spatial layer.
  std::vector<TimingFramesLayerInfo> timing_frames_info_ RTC_GUARDED_BY(&lock_);
  int64_t last_timing_frame_time_ms_ RTC_GUARDED_BY(&lock_);
  size_t reordered_frames_logged_messages_ RTC_GUARDED_BY(&lock_);
  size_t stalled_encoder_logged_messages_ RTC_GUARDED_BY(&lock_);
};

}  // namespace webrtc

#endif  // VIDEO_FRAME_ENCODE_METADATA_WRITER_H_