RemoteParticipant

 package io.livekit.android.room.participant
 
-import io.livekit.android.room.track.Track
-import io.livekit.android.room.track.TrackPublication
+import io.livekit.android.room.track.*
 
-class Participant(val sid: String, name: String? = null) {
+open class Participant(var sid: String, name: String? = null) {
     inline class Sid(val sid: String)
 
     var metadata: String? = null
@@ -20,10 +19,28 @@ class Participant(val sid: String, name: String? = null) {
     var dataTracks = mutableMapOf<Track.Sid, TrackPublication>()
         private set
 
-    fun addTrack(publication: TrackPublication){
+    fun addTrack(publication: TrackPublication) {
         tracks[publication.trackSid] = publication
-        when(publication) {
-
+        when (publication) {
+            is RemoteAudioTrackPublication -> audioTracks[publication.trackSid] = publication
+            is RemoteVideoTrackPublication -> videoTracks[publication.trackSid] = publication
+            is RemoteDataTrackPublication -> dataTracks[publication.trackSid] = publication
         }
     }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as Participant
+
+        if (sid != other.sid) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        return sid.hashCode()
+    }
+
 }
\ No newline at end of file

 package io.livekit.android.room.participant
 
-class RemoteParticipant {
+import com.github.ajalt.timberkt.Timber
+import io.livekit.android.room.track.*
+import io.livekit.android.util.CloseableCoroutineScope
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import livekit.Model
+import org.webrtc.AudioTrack
+import org.webrtc.DataChannel
+import org.webrtc.MediaStreamTrack
+import org.webrtc.VideoTrack
+import java.nio.ByteBuffer
+
+class RemoteParticipant(
+    sid: String, name: String? = null
+) : Participant(sid, name), RemoteDataTrack.Listener {
+
+    constructor(info: Model.ParticipantInfo) : this(info.sid, info.identity) {
+        updateFromInfo(info)
+    }
+
+    val remoteAudioTracks
+        get() = audioTracks.values.toList()
+    val remoteVideoTracks
+        get() = videoTracks.values.toList()
+    val remoteDataTracks
+        get() = dataTracks.values.toList()
+
+    val listener: Listener? = null
+
+    var participantInfo: Model.ParticipantInfo? = null
+
+    val hasInfo
+        get() = participantInfo != null
+
+    private val coroutineScope = CloseableCoroutineScope(SupervisorJob())
+
+    fun getTrackPublication(sid: Track.Sid): RemoteTrackPublication? =
+        tracks[sid] as? RemoteTrackPublication
+
+    fun updateFromInfo(info: Model.ParticipantInfo) {
+        val hadInfo = hasInfo
+        sid = info.sid
+        name = info.identity
+        participantInfo = info
+        metadata = info.metadata
+
+        val validTrackPublication = mutableMapOf<Track.Sid, RemoteTrackPublication>()
+        val newTrackPublications = mutableMapOf<Track.Sid, RemoteTrackPublication>()
+
+        for (trackInfo in info.tracksList) {
+            val trackSid = Track.Sid(trackInfo.sid)
+            var publication = getTrackPublication(trackSid)
+
+            if (publication == null) {
+                publication = when (trackInfo.type) {
+                    Model.TrackType.AUDIO -> RemoteAudioTrackPublication(trackInfo)
+                    Model.TrackType.VIDEO -> RemoteVideoTrackPublication(trackInfo)
+                    Model.TrackType.DATA -> RemoteDataTrackPublication(trackInfo)
+                    Model.TrackType.UNRECOGNIZED -> throw TrackException.InvalidTrackTypeException()
+                    null -> throw NullPointerException("trackInfo.type is null")
+                }
+
+                newTrackPublications[trackSid] = publication
+                addTrack(publication)
+            } else {
+                publication.updateFromInfo(trackInfo)
+            }
+
+            validTrackPublication[trackSid] = publication
+        }
+
+        if (hadInfo) {
+            for (publication in newTrackPublications.values) {
+                sendTrackPublishedEvent(publication)
+            }
+        }
+
+        val invalidKeys = tracks.keys - validTrackPublication.keys
+        for (invalidKey in invalidKeys) {
+            val publication = tracks[invalidKey] ?: continue
+            unpublishTrack(publication.trackSid, true)
+        }
+    }
+
+    fun addSubscribedMediaTrack(rtcTrack: MediaStreamTrack, sid: Track.Sid, triesLeft: Int = 20) {
+        val publication = getTrackPublication(sid)
+        val track: Track = when (val kind = rtcTrack.kind()) {
+            KIND_AUDIO -> RemoteAudioTrack(sid = sid, rtcTrack = rtcTrack as AudioTrack, name = "")
+            KIND_VIDEO -> RemoteVideoTrack(sid = sid, rtcTrack = rtcTrack as VideoTrack, name = "")
+            else -> throw TrackException.InvalidTrackTypeException("invalid track type: $kind")
+        }
+
+        if (publication == null) {
+            if (triesLeft == 0) {
+                val message = "Could not find published track with sid: $sid"
+                val exception = TrackException.InvalidTrackStateException(message)
+                Timber.e { "remote participant ${this.sid} --- $message" }
+                when (rtcTrack.kind()) {
+                    KIND_AUDIO -> {
+                        listener?.onFailToSubscribe(
+                            audioTrack = track as RemoteAudioTrack,
+                            exception = exception,
+                            participant = this
+                        )
+                    }
+
+                    KIND_VIDEO -> {
+                        listener?.onFailToSubscribe(
+                            videoTrack = track as RemoteVideoTrack,
+                            exception = exception,
+                            participant = this
+                        )
+                    }
+                }
+            } else {
+                coroutineScope.launch {
+                    delay(150)
+                    addSubscribedMediaTrack(rtcTrack, sid, triesLeft - 1)
+                }
+            }
+            return
+        }
+
+        val remoteTrack = track as RemoteTrack
+        publication.track = track
+        track.name = publication.trackName
+        remoteTrack.sid = publication.trackSid
+
+        when (publication) {
+            is RemoteAudioTrackPublication -> listener?.onSubscribe(publication, this)
+            is RemoteVideoTrackPublication -> listener?.onSubscribe(publication, this)
+            else -> throw TrackException.InvalidTrackTypeException()
+        }
+    }
+
+    fun addSubscribedDataTrack(rtcTrack: DataChannel, sid: Track.Sid, name: String) {
+        val track = RemoteDataTrack(sid, name, rtcTrack)
+        var publication = getTrackPublication(sid) as? RemoteDataTrackPublication
+
+        if (publication != null) {
+            publication.track = track
+        } else {
+            val trackInfo = Model.TrackInfo.newBuilder()
+                .setSid(sid.sid)
+                .setName(name)
+                .setType(Model.TrackType.DATA)
+                .build()
+            publication = RemoteDataTrackPublication(info = trackInfo, track = track)
+            addTrack(publication)
+            if (hasInfo) {
+                sendTrackPublishedEvent(publication)
+            }
+        }
+
+
+        rtcTrack.registerObserver(object : DataChannel.Observer {
+            override fun onBufferedAmountChange(previousAmount: Long) {}
+
+            override fun onStateChange() {
+                val newState = rtcTrack.state()
+                if (newState == DataChannel.State.CLOSED) {
+                    listener?.onUnsubscribe(publication, this@RemoteParticipant)
+                }
+            }
+
+            override fun onMessage(buffer: DataChannel.Buffer) {
+                listener?.onReceive(buffer.data, publication, this@RemoteParticipant)
+            }
+        })
+        listener?.onSubscribe(dataTrack = publication, participant = this)
+    }
+
+    private fun unpublishTrack(trackSid: Track.Sid, sendUnpublish: Boolean) {
+        val publication = tracks.remove(trackSid) ?: return
+
+        when (publication) {
+            is RemoteAudioTrackPublication -> audioTracks.remove(trackSid)
+            is RemoteVideoTrackPublication -> videoTracks.remove(trackSid)
+            is RemoteDataTrackPublication -> {
+                dataTracks.remove(trackSid)
+                publication.dataTrack?.rtcTrack?.unregisterObserver()
+            }
+            else -> throw TrackException.InvalidTrackTypeException()
+        }
+
+        if (publication.track != null) {
+            // TODO: need to stop track?
+            publication.track
+            sendTrackUnsubscribedEvent(publication)
+        }
+        if (sendUnpublish) {
+            sendTrackUnpublishedEvent(publication)
+        }
+    }
+
+    private fun sendTrackUnsubscribedEvent(publication: TrackPublication) {
+        when (publication) {
+            is RemoteAudioTrackPublication -> listener?.onUnsubscribe(publication, this)
+            is RemoteVideoTrackPublication -> listener?.onUnsubscribe(publication, this)
+            is RemoteDataTrackPublication -> listener?.onUnsubscribe(publication, this)
+            else -> throw TrackException.InvalidTrackTypeException()
+        }
+    }
+
+    private fun sendTrackUnpublishedEvent(publication: TrackPublication) {
+        when (publication) {
+            is RemoteAudioTrackPublication -> listener?.onUnpublish(publication, this)
+            is RemoteVideoTrackPublication -> listener?.onUnpublish(publication, this)
+            is RemoteDataTrackPublication -> listener?.onUnpublish(publication, this)
+            else -> throw TrackException.InvalidTrackTypeException()
+        }
+    }
+
+    private fun sendTrackPublishedEvent(publication: RemoteTrackPublication) {
+        when (publication) {
+            is RemoteAudioTrackPublication -> listener?.onPublish(publication, this)
+            is RemoteVideoTrackPublication -> listener?.onPublish(publication, this)
+            is RemoteDataTrackPublication -> listener?.onPublish(publication, this)
+            else -> throw TrackException.InvalidTrackTypeException()
+        }
+    }
+
+    override fun onReceiveString(message: String, dataTrack: DataTrack) {
+        TODO("Not yet implemented")
+    }
+
+    override fun onReceiveData(message: DataChannel.Buffer, dataTrack: DataTrack) {
+        TODO("Not yet implemented")
+    }
+
+    companion object {
+        private const val KIND_AUDIO = "audio"
+        private const val KIND_VIDEO = "video"
+    }
+
+    interface Listener {
+        fun onPublish(audioTrack: RemoteAudioTrackPublication, participant: RemoteParticipant)
+        fun onUnpublish(audioTrack: RemoteAudioTrackPublication, participant: RemoteParticipant)
+        fun onPublish(videoTrack: RemoteVideoTrackPublication, participant: RemoteParticipant)
+        fun onUnpublish(videoTrack: RemoteVideoTrackPublication, participant: RemoteParticipant)
+        fun onPublish(dataTrack: RemoteDataTrackPublication, participant: RemoteParticipant)
+        fun onUnpublish(dataTrack: RemoteDataTrackPublication, participant: RemoteParticipant)
+
+        fun onEnable(audioTrack: RemoteAudioTrackPublication, participant: RemoteParticipant)
+        fun onDisable(audioTrack: RemoteAudioTrackPublication, participant: RemoteParticipant)
+        fun onEnable(videoTrack: RemoteVideoTrackPublication, participant: RemoteParticipant)
+        fun onDisable(videoTrack: RemoteVideoTrackPublication, participant: RemoteParticipant)
+
+        fun onSubscribe(audioTrack: RemoteAudioTrackPublication, participant: RemoteParticipant)
+        fun onFailToSubscribe(
+            audioTrack: RemoteAudioTrack,
+            exception: Exception,
+            participant: RemoteParticipant
+        )
+
+        fun onUnsubscribe(audioTrack: RemoteAudioTrackPublication, participant: RemoteParticipant)
+
+        fun onSubscribe(videoTrack: RemoteVideoTrackPublication, participant: RemoteParticipant)
+        fun onFailToSubscribe(
+            videoTrack: RemoteVideoTrack,
+            exception: Exception,
+            participant: RemoteParticipant
+        )
+
+        fun onUnsubscribe(videoTrack: RemoteVideoTrackPublication, participant: RemoteParticipant)
+
+        fun onSubscribe(dataTrack: RemoteDataTrackPublication, participant: RemoteParticipant)
+        fun onFailToSubscribe(
+            dataTrack: RemoteDataTrackPublication,
+            exception: Exception,
+            participant: RemoteParticipant
+        )
+
+        fun onUnsubscribe(dataTrack: RemoteDataTrackPublication, participant: RemoteParticipant)
+        fun onReceive(
+            data: ByteBuffer,
+            dataTrack: RemoteDataTrackPublication,
+            participant: RemoteParticipant
+        )
+
+        //fun networkQualityDidChange(networkQualityLevel: NetworkQualityLevel, participant: remoteParticipant)
+        fun switchedOffVideo(track: RemoteVideoTrack, participant: RemoteParticipant)
+        fun switchedOnVideo(track: RemoteVideoTrack, participant: RemoteParticipant)
+//        fun onChangePublishPriority(videoTrack: RemoteVideoTrackPublication, priority: PublishPriority, participant: RemoteParticipant)
+//        fun onChangePublishPriority(audioTrack: RemoteAudioTrackPublication, priority: PublishPriority, participant: RemoteParticipant)
+//        fun onChangePublishPriority(dataTrack: RemoteDataTrackPublication, priority: PublishPriority, participant: RemoteParticipant)
+    }
+
 }
\ No newline at end of file

+package io.livekit.android.room.track
+
+import org.webrtc.DataChannel
+
+open class DataTrack(
+    name: String,
+    val rtcTrack: DataChannel
+) : Track(name, stateFromRTCDataChannelState(rtcTrack.state())) {
+
+    /**
+     * TODO: These values are only available at [DataChannel.Init]
+     */
+    val ordered: Boolean = TODO()
+    val maxPacketLifeTime: Int = TODO()
+    val maxRetransmits: Int = TODO()
+    
+}
\ No newline at end of file

+package io.livekit.android.room.track
+
+interface DataTrackPublication {
+    val dataTrack: DataTrack?
+}
\ No newline at end of file

+package io.livekit.android.room.track
+
+import org.webrtc.DataChannel
+
+class RemoteDataTrack(
+    override var sid: Sid,
+    name: String,
+    rtcTrack: DataChannel
+) :
+    DataTrack(name, rtcTrack),
+    RemoteTrack {
+
+    var listener: Listener? = null
+
+    interface Listener {
+        fun onReceiveString(message: String, dataTrack: DataTrack)
+        fun onReceiveData(message: DataChannel.Buffer, dataTrack: DataTrack)
+    }
+}
\ No newline at end of file

+package io.livekit.android.room.track
+
+import livekit.Model
+
+class RemoteDataTrackPublication(
+    info: Model.TrackInfo,
+    track: Track? = null
+) : RemoteTrackPublication(info, track), DataTrackPublication {
+    override val dataTrack: DataTrack?
+        get() = track as? DataTrack
+}
\ No newline at end of file