flesh out rtcclient

@@ -37,14 +37,12 @@ android {
 
 protobuf {
     protoc {
-        // You still need protoc like in the non-Android case
         artifact = "com.google.protobuf:protoc:${versions.protobuf}"
     }
     generateProtoTasks {
         all().each { task ->
             task.builtins {
                 java {
-                    option "lite"
                 }
             }
         }

 package io.livekit.android.room
 
 import com.github.ajalt.timberkt.Timber
+import com.google.protobuf.util.JsonFormat
+import livekit.Model
+import livekit.Rtc
 import okhttp3.Request
 import okhttp3.Response
 import okhttp3.WebSocket
 import okhttp3.WebSocketListener
 import okio.ByteString
+import org.webrtc.SessionDescription
 import javax.inject.Inject
 
 internal class RTCClient
 @Inject
 constructor(
     private val websocketFactory: WebSocket.Factory,
+    private val fromJson: JsonFormat.Parser,
+    private val toJson: JsonFormat.Printer,
 ) : WebSocketListener() {
 
     private var isConnected = false
     private var currentWs: WebSocket? = null
+    var listener: Listener? = null
+
     fun connect(
         host: String,
         token: String,
@@ -37,7 +45,21 @@ constructor(
     }
 
     override fun onMessage(webSocket: WebSocket, text: String) {
-        super.onMessage(webSocket, text)
+        val signalResponseBuilder = Rtc.SignalResponse.newBuilder()
+        fromJson.merge(text, signalResponseBuilder)
+        val response = signalResponseBuilder.build()
+
+        if (!isConnected) {
+            // Only handle joins if not connected.
+            if (response.hasJoin()) {
+                isConnected = true
+                listener?.onJoin(response.join)
+            } else {
+                Timber.e { "out of order message?" }
+            }
+            return
+        }
+        handleSignalResponse(response)
     }
 
     override fun onMessage(webSocket: WebSocket, bytes: ByteString) {
@@ -56,4 +78,78 @@ constructor(
         super.onFailure(webSocket, t, response)
     }
 
+
+    fun fromProtoSessionDescription(sd: Rtc.SessionDescription): SessionDescription {
+        val rtcSdpType = when (sd.type) {
+            SD_TYPE_ANSWER -> SessionDescription.Type.ANSWER
+            SD_TYPE_OFFER -> SessionDescription.Type.OFFER
+            SD_TYPE_PRANSWER -> SessionDescription.Type.PRANSWER
+            else -> throw IllegalArgumentException("invalid RTC SdpType: ${sd.type}")
+        }
+        return SessionDescription(rtcSdpType, sd.sdp)
+    }
+
+    fun toProtoSessionDescription(sdp: SessionDescription): Rtc.SessionDescription {
+        val sdBuilder = Rtc.SessionDescription.newBuilder()
+        sdBuilder.sdp = sdp.description
+        sdBuilder.type = when (sdp.type) {
+            SessionDescription.Type.ANSWER -> SD_TYPE_ANSWER
+            SessionDescription.Type.OFFER -> SD_TYPE_OFFER
+            SessionDescription.Type.PRANSWER -> SD_TYPE_PRANSWER
+            else -> throw IllegalArgumentException("invalid RTC SdpType: ${sdp.type}")
+        }
+
+        return sdBuilder.build()
+    }
+
+    fun handleSignalResponse(response: Rtc.SignalResponse) {
+        if (!isConnected) {
+            Timber.e { "Received response while not connected. ${toJson.print(response)}" }
+            return
+        }
+        when (response.messageCase) {
+            Rtc.SignalResponse.MessageCase.ANSWER -> {
+                val sd = fromProtoSessionDescription(response.answer)
+                listener?.onAnswer(sd)
+            }
+            Rtc.SignalResponse.MessageCase.OFFER -> {
+                val sd = fromProtoSessionDescription(response.offer)
+                listener?.onOffer(sd)
+            }
+//            Rtc.SignalResponse.MessageCase.TRICKLE -> {
+//                TODO()
+//            }
+            Rtc.SignalResponse.MessageCase.UPDATE -> {
+                listener?.onParticipantUpdate(response.update.participantsList)
+            }
+            Rtc.SignalResponse.MessageCase.TRACK_PUBLISHED -> {
+                listener?.onLocalTrackPublished(response.trackPublished)
+            }
+            Rtc.SignalResponse.MessageCase.SPEAKER -> TODO()
+            Rtc.SignalResponse.MessageCase.MESSAGE_NOT_SET -> TODO()
+            else -> {
+                Timber.v { "unhandled response type: ${response.messageCase.name}" }
+            }
+        }
+
+    }
+
+    interface Listener {
+        fun onJoin(info: Rtc.JoinResponse)
+
+        fun onAnswer(sessionDescription: SessionDescription)
+        fun onOffer(sessionDescription: SessionDescription)
+
+        //fun onTrickle(candidate: RTCIceCandidate, target: Rtc.SignalTarget)
+        fun onLocalTrackPublished(trackPublished: Rtc.TrackPublishedResponse)
+        fun onParticipantUpdate(updates: List<Model.ParticipantInfo>)
+        fun onClose(reason: String, code: Int)
+        fun onError(error: Error)
+    }
+
+    companion object {
+        const val SD_TYPE_ANSWER = "answer"
+        const val SD_TYPE_OFFER = "offer"
+        const val SD_TYPE_PRANSWER = "pranswer"
+    }
 }
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