// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "third_party/blink/renderer/modules/peerconnection/rtc_rtp_receiver_impl.h"

#include "base/check_op.h"
#include "base/feature_list.h"
#include "base/functional/bind.h"
#include "base/notreached.h"
#include "base/task/single_thread_task_runner.h"
#include "third_party/blink/renderer/modules/mediastream/video_track_adapter.h"  // For kMediaStreamTrackEmptyVideoFrameMonitor.
#include "third_party/blink/renderer/modules/peerconnection/peer_connection_features.h"
#include "third_party/blink/renderer/platform/peerconnection/rtc_encoded_audio_stream_transformer.h"
#include "third_party/blink/renderer/platform/peerconnection/rtc_encoded_video_stream_transformer.h"
#include "third_party/blink/renderer/platform/peerconnection/rtc_rtp_sender_platform.h"
#include "third_party/blink/renderer/platform/peerconnection/rtc_rtp_source.h"
#include "third_party/blink/renderer/platform/peerconnection/rtc_stats.h"
#include "third_party/blink/renderer/platform/wtf/thread_safe_ref_counted.h"
#include "third_party/webrtc/api/scoped_refptr.h"

namespace blink {

RtpReceiverState::RtpReceiverState(
    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
    scoped_refptr<base::SingleThreadTaskRunner> signaling_task_runner,
    scoped_refptr<webrtc::RtpReceiverInterface> webrtc_receiver,
    std::unique_ptr<blink::WebRtcMediaStreamTrackAdapterMap::AdapterRef>
        track_ref,
    std::vector<std::string> stream_id)
    : main_task_runner_(std::move(main_task_runner)),
      signaling_task_runner_(std::move(signaling_task_runner)),
      webrtc_receiver_(std::move(webrtc_receiver)),
      webrtc_dtls_transport_(webrtc_receiver_->dtls_transport()),
      webrtc_dtls_transport_information_(webrtc::DtlsTransportState::kNew),
      is_initialized_(false),
      track_ref_(std::move(track_ref)),
      stream_ids_(std::move(stream_id)) {
  DCHECK(main_task_runner_);
  DCHECK(signaling_task_runner_);
  DCHECK(webrtc_receiver_);
  DCHECK(track_ref_);
  if (webrtc_dtls_transport_) {
    webrtc_dtls_transport_information_ = webrtc_dtls_transport_->Information();
  }
}

RtpReceiverState::RtpReceiverState(RtpReceiverState&& other)
    : main_task_runner_(other.main_task_runner_),
      signaling_task_runner_(other.signaling_task_runner_),
      webrtc_receiver_(std::move(other.webrtc_receiver_)),
      webrtc_dtls_transport_(std::move(other.webrtc_dtls_transport_)),
      webrtc_dtls_transport_information_(
          other.webrtc_dtls_transport_information_),
      is_initialized_(other.is_initialized_),
      track_ref_(std::move(other.track_ref_)),
      stream_ids_(std::move(other.stream_ids_)) {
  // Explicitly null |other|'s task runners for use in destructor.
  other.main_task_runner_ = nullptr;
  other.signaling_task_runner_ = nullptr;
}

RtpReceiverState::~RtpReceiverState() {
  // It's OK to not be on the main thread if this state has been moved, in which
  // case |main_task_runner_| is null.
  DCHECK(!main_task_runner_ || main_task_runner_->BelongsToCurrentThread());
}

RtpReceiverState& RtpReceiverState::operator=(RtpReceiverState&& other) {
  DCHECK_EQ(main_task_runner_, other.main_task_runner_);
  DCHECK_EQ(signaling_task_runner_, other.signaling_task_runner_);
  // Explicitly null |other|'s task runners for use in destructor.
  other.main_task_runner_ = nullptr;
  other.signaling_task_runner_ = nullptr;
  webrtc_receiver_ = std::move(other.webrtc_receiver_);
  webrtc_dtls_transport_ = std::move(other.webrtc_dtls_transport_);
  webrtc_dtls_transport_information_ = other.webrtc_dtls_transport_information_;
  track_ref_ = std::move(other.track_ref_);
  stream_ids_ = std::move(other.stream_ids_);
  return *this;
}

bool RtpReceiverState::is_initialized() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return is_initialized_;
}

void RtpReceiverState::Initialize() {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  if (is_initialized_)
    return;
  track_ref_->InitializeOnMainThread();
  is_initialized_ = true;
}

scoped_refptr<base::SingleThreadTaskRunner> RtpReceiverState::main_task_runner()
    const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return main_task_runner_;
}

scoped_refptr<base::SingleThreadTaskRunner>
RtpReceiverState::signaling_task_runner() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return signaling_task_runner_;
}

scoped_refptr<webrtc::RtpReceiverInterface> RtpReceiverState::webrtc_receiver()
    const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return webrtc_receiver_;
}

webrtc::scoped_refptr<webrtc::DtlsTransportInterface>
RtpReceiverState::webrtc_dtls_transport() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return webrtc_dtls_transport_;
}

webrtc::DtlsTransportInformation
RtpReceiverState::webrtc_dtls_transport_information() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return webrtc_dtls_transport_information_;
}

const std::unique_ptr<blink::WebRtcMediaStreamTrackAdapterMap::AdapterRef>&
RtpReceiverState::track_ref() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return track_ref_;
}

const std::vector<std::string>& RtpReceiverState::stream_ids() const {
  DCHECK(main_task_runner_->BelongsToCurrentThread());
  return stream_ids_;
}

class RTCRtpReceiverImpl::RTCRtpReceiverInternal
    : public ThreadSafeRefCounted<
          RTCRtpReceiverImpl::RTCRtpReceiverInternal,
          RTCRtpReceiverImpl::RTCRtpReceiverInternalTraits>,
      public webrtc::RtpReceiverObserverInterface {
 public:
  RTCRtpReceiverInternal(webrtc::scoped_refptr<webrtc::PeerConnectionInterface>
                             native_peer_connection,
                         RtpReceiverState state,
                         std::unique_ptr<webrtc::Metronome> decode_metronome)
      : native_peer_connection_(std::move(native_peer_connection)),
        main_task_runner_(state.main_task_runner()),
        signaling_task_runner_(state.signaling_task_runner()),
        webrtc_receiver_(state.webrtc_receiver()),
        state_(std::move(state)) {
    DCHECK(native_peer_connection_);
    DCHECK(state_.is_initialized());
    if (webrtc_receiver_->media_type() == webrtc::MediaType::AUDIO) {
      encoded_audio_transformer_ =
          std::make_unique<RTCEncodedAudioStreamTransformer>(main_task_runner_);
      webrtc_receiver_->SetFrameTransformer(
          encoded_audio_transformer_->Delegate());
    } else {
      CHECK(webrtc_receiver_->media_type() == webrtc::MediaType::VIDEO);
      encoded_video_transformer_ =
          std::make_unique<RTCEncodedVideoStreamTransformer>(
              main_task_runner_, std::move(decode_metronome));
      webrtc_receiver_->SetFrameTransformer(
          encoded_video_transformer_->Delegate());
    }
    DCHECK(!encoded_audio_transformer_ || !encoded_video_transformer_);
    CHECK(webrtc_receiver_);
    webrtc_receiver_->SetObserver(this);
  }

  const RtpReceiverState& state() const {
    DCHECK(main_task_runner_->BelongsToCurrentThread());
    return state_;
  }

  void set_state(RtpReceiverState state) {
    DCHECK(main_task_runner_->BelongsToCurrentThread());
    DCHECK(state.main_task_runner() == main_task_runner_);
    DCHECK(state.signaling_task_runner() == signaling_task_runner_);
    DCHECK(state.webrtc_receiver() == webrtc_receiver_);
    DCHECK(state.is_initialized());
    state_ = std::move(state);
  }

  Vector<std::unique_ptr<RTCRtpSource>> GetSources() {
    // The `webrtc_recever_` is a PROXY and GetSources block-invokes to its
    // secondary thread, which is the WebRTC worker thread.
    auto webrtc_sources = webrtc_receiver_->GetSources();
    Vector<std::unique_ptr<RTCRtpSource>> sources(
        static_cast<wtf_size_t>(webrtc_sources.size()));
    for (wtf_size_t i = 0; i < webrtc_sources.size(); ++i) {
      sources[i] = std::make_unique<RTCRtpSource>(webrtc_sources[i]);
    }
    return sources;
  }

  void GetStats(RTCStatsReportCallback callback) {
    signaling_task_runner_->PostTask(
        FROM_HERE,
        base::BindOnce(&RTCRtpReceiverInternal::GetStatsOnSignalingThread, this,
                       std::move(callback)));
  }

  std::unique_ptr<webrtc::RtpParameters> GetParameters() {
    return std::make_unique<webrtc::RtpParameters>(
        webrtc_receiver_->GetParameters());
  }

  void SetJitterBufferMinimumDelay(std::optional<double> delay_seconds) {
    webrtc_receiver_->SetJitterBufferMinimumDelay(delay_seconds);
  }

  RTCEncodedAudioStreamTransformer* GetEncodedAudioStreamTransformer() const {
    return encoded_audio_transformer_.get();
  }

  RTCEncodedVideoStreamTransformer* GetEncodedVideoStreamTransformer() const {
    return encoded_video_transformer_.get();
  }

  // RtpReceiverObserverInterface implementation.
  void OnFirstPacketReceived(webrtc::MediaType media_type) override {
    // No-op.
  }
  void OnFirstPacketReceivedAfterReceptiveChange(
      webrtc::MediaType media_type) override {
    DCHECK(webrtc_receiver_);
    if (!main_task_runner_->BelongsToCurrentThread()) {
      main_task_runner_->PostTask(
          FROM_HERE,
          base::BindOnce(&RTCRtpReceiverImpl::RTCRtpReceiverInternal::
                             OnFirstPacketReceivedAfterReceptiveChange,
                         this, media_type));
      return;
    }
    state_.track_ref()->track()->Source()->SetReadyState(
        MediaStreamSource::kReadyStateLive);
  }

 private:
  friend class ThreadSafeRefCounted<RTCRtpReceiverInternal,
                                    RTCRtpReceiverInternalTraits>;
  friend struct RTCRtpReceiverImpl::RTCRtpReceiverInternalTraits;

  ~RTCRtpReceiverInternal() override {
    DCHECK(main_task_runner_->BelongsToCurrentThread());
    if (webrtc_receiver_) {
      webrtc_receiver_->SetObserver(nullptr);
    }
  }

  void GetStatsOnSignalingThread(RTCStatsReportCallback callback) {
    native_peer_connection_->GetStats(
        webrtc::scoped_refptr<webrtc::RtpReceiverInterface>(
            webrtc_receiver_.get()),
        CreateRTCStatsCollectorCallback(main_task_runner_,
                                        std::move(callback)));
  }

  const webrtc::scoped_refptr<webrtc::PeerConnectionInterface>
      native_peer_connection_;
  // Task runners and webrtc receiver: Same information as stored in
  // |state_| but const and safe to touch on the signaling thread to
  // avoid race with set_state().
  const scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
  const scoped_refptr<base::SingleThreadTaskRunner> signaling_task_runner_;
  const scoped_refptr<webrtc::RtpReceiverInterface> webrtc_receiver_;
  std::unique_ptr<RTCEncodedAudioStreamTransformer> encoded_audio_transformer_;
  std::unique_ptr<RTCEncodedVideoStreamTransformer> encoded_video_transformer_;
  RtpReceiverState state_;
};

struct RTCRtpReceiverImpl::RTCRtpReceiverInternalTraits {
  static void Destruct(const RTCRtpReceiverInternal* receiver) {
    // RTCRtpReceiverInternal owns AdapterRefs which have to be destroyed on the
    // main thread, this ensures delete always happens there.
    if (!receiver->main_task_runner_->BelongsToCurrentThread()) {
      receiver->main_task_runner_->PostTask(
          FROM_HERE,
          base::BindOnce(
              &RTCRtpReceiverImpl::RTCRtpReceiverInternalTraits::Destruct,
              base::Unretained(receiver)));
      return;
    }
    delete receiver;
  }
};

uintptr_t RTCRtpReceiverImpl::getId(
    const webrtc::RtpReceiverInterface* webrtc_rtp_receiver) {
  return reinterpret_cast<uintptr_t>(webrtc_rtp_receiver);
}

RTCRtpReceiverImpl::RTCRtpReceiverImpl(
    webrtc::scoped_refptr<webrtc::PeerConnectionInterface>
        native_peer_connection,
    RtpReceiverState state,
    std::unique_ptr<webrtc::Metronome> decode_metronome)
    : internal_(base::MakeRefCounted<RTCRtpReceiverInternal>(
          std::move(native_peer_connection),
          std::move(state),
          std::move(decode_metronome))) {}

RTCRtpReceiverImpl::RTCRtpReceiverImpl(const RTCRtpReceiverImpl& other)
    : internal_(other.internal_) {}

RTCRtpReceiverImpl::~RTCRtpReceiverImpl() {}

RTCRtpReceiverImpl& RTCRtpReceiverImpl::operator=(
    const RTCRtpReceiverImpl& other) {
  internal_ = other.internal_;
  return *this;
}

const RtpReceiverState& RTCRtpReceiverImpl::state() const {
  return internal_->state();
}

void RTCRtpReceiverImpl::set_state(RtpReceiverState state) {
  internal_->set_state(std::move(state));
}

std::unique_ptr<RTCRtpReceiverPlatform> RTCRtpReceiverImpl::ShallowCopy()
    const {
  return std::make_unique<RTCRtpReceiverImpl>(*this);
}

uintptr_t RTCRtpReceiverImpl::Id() const {
  return getId(internal_->state().webrtc_receiver().get());
}

webrtc::scoped_refptr<webrtc::DtlsTransportInterface>
RTCRtpReceiverImpl::DtlsTransport() {
  return internal_->state().webrtc_dtls_transport();
}

webrtc::DtlsTransportInformation
RTCRtpReceiverImpl::DtlsTransportInformation() {
  return internal_->state().webrtc_dtls_transport_information();
}

MediaStreamComponent* RTCRtpReceiverImpl::Track() const {
  return internal_->state().track_ref()->track();
}

Vector<String> RTCRtpReceiverImpl::StreamIds() const {
  const auto& stream_ids = internal_->state().stream_ids();
  Vector<String> wtf_stream_ids(static_cast<wtf_size_t>(stream_ids.size()));
  for (wtf_size_t i = 0; i < stream_ids.size(); ++i) {
    wtf_stream_ids[i] = String::FromUtf8(stream_ids[i]);
  }
  return wtf_stream_ids;
}

Vector<std::unique_ptr<RTCRtpSource>> RTCRtpReceiverImpl::GetSources() {
  return internal_->GetSources();
}

void RTCRtpReceiverImpl::GetStats(RTCStatsReportCallback callback) {
  internal_->GetStats(std::move(callback));
}

std::unique_ptr<webrtc::RtpParameters> RTCRtpReceiverImpl::GetParameters()
    const {
  return internal_->GetParameters();
}

void RTCRtpReceiverImpl::SetJitterBufferMinimumDelay(
    std::optional<double> delay_seconds) {
  internal_->SetJitterBufferMinimumDelay(delay_seconds);
}

RTCEncodedAudioStreamTransformer*
RTCRtpReceiverImpl::GetEncodedAudioStreamTransformer() const {
  return internal_->GetEncodedAudioStreamTransformer();
}

RTCEncodedVideoStreamTransformer*
RTCRtpReceiverImpl::GetEncodedVideoStreamTransformer() const {
  return internal_->GetEncodedVideoStreamTransformer();
}
}  // namespace blink