/*
 *  Copyright 2011 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 "pc/media_stream.h"

#include <cstddef>
#include <string>
#include <utility>

#include "absl/strings/string_view.h"
#include "api/make_ref_counted.h"
#include "api/media_stream_interface.h"
#include "api/scoped_refptr.h"
#include "rtc_base/checks.h"

namespace webrtc {

template <class V>
static typename V::iterator FindTrack(V* vector, const std::string& track_id) {
  typename V::iterator it = vector->begin();
  for (; it != vector->end(); ++it) {
    if ((*it)->id() == track_id) {
      break;
    }
  }
  return it;
}

scoped_refptr<MediaStream> MediaStream::Create(absl::string_view id) {
  return make_ref_counted<MediaStream>(id);
}

MediaStream::MediaStream(absl::string_view id) : id_(id) {}

bool MediaStream::AddTrack(scoped_refptr<AudioTrackInterface> track) {
  return AddTrack<AudioTrackVector, AudioTrackInterface>(&audio_tracks_, track);
}

bool MediaStream::AddTrack(scoped_refptr<VideoTrackInterface> track) {
  return AddTrack<VideoTrackVector, VideoTrackInterface>(&video_tracks_, track);
}

bool MediaStream::RemoveTrack(scoped_refptr<AudioTrackInterface> track) {
  return RemoveTrack<AudioTrackVector>(&audio_tracks_, track);
}

bool MediaStream::RemoveTrack(scoped_refptr<VideoTrackInterface> track) {
  return RemoveTrack<VideoTrackVector>(&video_tracks_, track);
}

scoped_refptr<AudioTrackInterface> MediaStream::FindAudioTrack(
    const std::string& track_id) {
  AudioTrackVector::iterator it = FindTrack(&audio_tracks_, track_id);
  if (it == audio_tracks_.end())
    return nullptr;
  return *it;
}

scoped_refptr<VideoTrackInterface> MediaStream::FindVideoTrack(
    const std::string& track_id) {
  VideoTrackVector::iterator it = FindTrack(&video_tracks_, track_id);
  if (it == video_tracks_.end())
    return nullptr;
  return *it;
}

template <typename TrackVector, typename Track>
bool MediaStream::AddTrack(TrackVector* tracks, scoped_refptr<Track> track) {
  typename TrackVector::iterator it = FindTrack(tracks, track->id());
  if (it != tracks->end())
    return false;
  tracks->emplace_back(std::move((track)));
  FireOnChanged();
  return true;
}

template <typename TrackVector>
bool MediaStream::RemoveTrack(TrackVector* tracks,
                              scoped_refptr<MediaStreamTrackInterface> track) {
  RTC_DCHECK(tracks != nullptr);
  if (!track)
    return false;
  typename TrackVector::iterator it = FindTrack(tracks, track->id());
  if (it == tracks->end())
    return false;
  tracks->erase(it);
  FireOnChanged();
  return true;
}

}  // namespace webrtc