feat: added basic call functionality

libsession/src/main/java/org/session/libsession/messaging/messages/control/CallMessage.kt

@@ -0,0 +1,57 @@
+package org.session.libsession.messaging.messages.control
+
+import org.session.libsignal.protos.SignalServiceProtos
+import org.session.libsignal.utilities.Log
+
+class CallMessage(): ControlMessage() {
+    var type: SignalServiceProtos.CallMessage.Type? = null
+    var sdps: List<String> = listOf()
+    var sdpMLineIndexes: List<Int> = listOf()
+    var sdpMids: List<String> = listOf()
+
+    override val isSelfSendValid: Boolean = false
+
+    override fun isValid(): Boolean = super.isValid() && type != null && !sdps.isNullOrEmpty()
+
+    constructor(type: SignalServiceProtos.CallMessage.Type,
+                sdps: List<String>,
+                sdpMLineIndexes: List<Int>,
+                sdpMids: List<String>) : this() {
+        this.type = type
+        this.sdps = sdps
+        this.sdpMLineIndexes = sdpMLineIndexes
+        this.sdpMids = sdpMids
+    }
+
+    companion object {
+        const val TAG = "CallMessage"
+
+        fun fromProto(proto: SignalServiceProtos.Content): CallMessage? {
+            val callMessageProto = if (proto.hasCallMessage()) proto.callMessage else return null
+            val type = callMessageProto.type
+            val sdps = callMessageProto.sdpsList
+            val sdpMLineIndexes = callMessageProto.sdpMLineIndexesList
+            val sdpMids = callMessageProto.sdpMidsList
+            return CallMessage(type,sdps, sdpMLineIndexes, sdpMids)
+        }
+    }
+
+    override fun toProto(): SignalServiceProtos.Content? {
+        val nonNullType = type ?: run {
+            Log.w(TAG,"Couldn't construct call message request proto from: $this")
+            return null
+        }
+
+        val callMessage = SignalServiceProtos.CallMessage.newBuilder()
+            .setType(nonNullType)
+            .addAllSdps(sdps)
+            .addAllSdpMLineIndexes(sdpMLineIndexes)
+            .addAllSdpMids(sdpMids)
+
+        return SignalServiceProtos.Content.newBuilder()
+            .setCallMessage(
+                callMessage
+            )
+            .build()
+    }
+}

libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiver.kt

@@ -95,6 +95,7 @@ object MessageReceiver {
             ExpirationTimerUpdate.fromProto(proto) ?:
             ConfigurationMessage.fromProto(proto) ?:
             UnsendRequest.fromProto(proto) ?:
+            CallMessage.fromProto(proto) ?:
             VisibleMessage.fromProto(proto) ?: throw Error.UnknownMessage
         // Ignore self send if needed
         if (!message.isSelfSendValid && sender == userPublicKey) throw Error.SelfSend

libsession/src/main/java/org/session/libsession/messaging/sending_receiving/ReceivedMessageHandler.kt

@@ -14,24 +14,20 @@ import org.session.libsession.messaging.sending_receiving.link_preview.LinkPrevi
 import org.session.libsession.messaging.sending_receiving.notifications.PushNotificationAPI
 import org.session.libsession.messaging.sending_receiving.pollers.ClosedGroupPollerV2
 import org.session.libsession.messaging.sending_receiving.quotes.QuoteModel
+import org.session.libsession.messaging.utilities.WebRtcUtils
 import org.session.libsession.snode.SnodeAPI
-import org.session.libsession.utilities.Address
-import org.session.libsession.utilities.GroupRecord
+import org.session.libsession.utilities.*
 import org.session.libsession.utilities.recipients.Recipient
-import org.session.libsession.utilities.GroupUtil
-import org.session.libsession.utilities.SSKEnvironment
-import org.session.libsession.utilities.TextSecurePreferences
-import org.session.libsession.utilities.ProfileKeyUtil
 import org.session.libsignal.crypto.ecc.DjbECPrivateKey
 import org.session.libsignal.crypto.ecc.DjbECPublicKey
 import org.session.libsignal.crypto.ecc.ECKeyPair
-import org.session.libsignal.utilities.guava.Optional
 import org.session.libsignal.messages.SignalServiceGroup
 import org.session.libsignal.protos.SignalServiceProtos
-import org.session.libsignal.utilities.removing05PrefixIfNeeded
-import org.session.libsignal.utilities.toHexString
 import org.session.libsignal.utilities.Base64
 import org.session.libsignal.utilities.Log
+import org.session.libsignal.utilities.guava.Optional
+import org.session.libsignal.utilities.removing05PrefixIfNeeded
+import org.session.libsignal.utilities.toHexString
 import java.security.MessageDigest
 import java.util.*
 import kotlin.collections.ArrayList
@@ -52,6 +48,7 @@ fun MessageReceiver.handle(message: Message, proto: SignalServiceProtos.Content,
         is ConfigurationMessage -> handleConfigurationMessage(message)
         is UnsendRequest -> handleUnsendRequest(message)
         is VisibleMessage -> handleVisibleMessage(message, proto, openGroupID)
+        is CallMessage -> handleCallMessage(message)
     }
 }
 
@@ -61,6 +58,11 @@ private fun MessageReceiver.handleReadReceipt(message: ReadReceipt) {
     SSKEnvironment.shared.readReceiptManager.processReadReceipts(context, message.sender!!, message.timestamps!!, message.receivedTimestamp!!)
 }
 
+private fun MessageReceiver.handleCallMessage(message: CallMessage) {
+    // TODO: refactor this out to persistence, just to help debug the flow and send/receive in synchronous testing
+    WebRtcUtils.SIGNAL_QUEUE.offer(message)
+}
+
 private fun MessageReceiver.handleTypingIndicator(message: TypingIndicator) {
     when (message.kind!!) {
         TypingIndicator.Kind.STARTED -> showTypingIndicatorIfNeeded(message.sender!!)

libsession/src/main/java/org/session/libsession/messaging/utilities/WebRtcUtils.kt

@@ -0,0 +1,11 @@
+package org.session.libsession.messaging.utilities
+
+import kotlinx.coroutines.channels.Channel
+import org.session.libsession.messaging.messages.control.CallMessage
+
+object WebRtcUtils {
+
+    // TODO: move this to a better place that is persistent
+    val SIGNAL_QUEUE = Channel<CallMessage>(Channel.UNLIMITED)
+
+}