Add support for Realtime Protocol V2

Author: jan-tennert

Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/Realtime.kt

@@ -146,6 +146,7 @@ interface Realtime : MainPlugin<Realtime.Config>, CustomSerializationPlugin {
         var connectOnSubscribe: Boolean = true
         @SupabaseInternal var websocketFactory: RealtimeWebsocketFactory? = null
         var disconnectOnNoSubscriptions: Boolean = true
+        var vsn = RealtimeProtocolVersion.V2
         override var requireValidSession: Boolean = false
 
         internal var customAccessTokenProvider = false

Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/RealtimeImpl.kt

@@ -308,7 +308,7 @@ import kotlin.time.Duration
     private fun realtimeWebsocketUrl(): String {
         return buildUrl(realtimeBaseUrl()) {
             parameters["apikey"] = supabaseClient.supabaseKey
-            parameters["vsn"] = "1.0.0"
+            parameters["vsn"] = config.vsn.value
             pathSegments += listOf("websocket")
         }
     }

Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/RealtimeProtocolVersion.kt

@@ -0,0 +1,16 @@
+package io.github.jan.supabase.realtime
+
+/**
+ * Phoenix protocol version used for WebSocket communication.
+ */
+enum class RealtimeProtocolVersion(val value: String) {
+    /**
+     * Protocol 1.0.0 — JSON object text frames for all messages.
+     */
+    V1("1.0.0"),
+    /**
+     * Protocol 2.0.0 — JSON array text frames for non-broadcast messages,
+     * binary frames for broadcast messages
+     */
+    V2("2.0.0")
+}

Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/websocket/KtorRealtimeWebsocket.kt

@@ -1,8 +1,8 @@
 package io.github.jan.supabase.realtime.websocket
 
 import io.github.jan.supabase.realtime.RealtimeMessage
+import io.github.jan.supabase.realtime.RealtimeProtocolVersion
 import io.ktor.client.plugins.websocket.DefaultClientWebSocketSession
-import io.ktor.client.plugins.websocket.receiveDeserialized
 import io.ktor.client.plugins.websocket.sendSerialized
 import kotlinx.coroutines.cancel
 import kotlinx.coroutines.isActive
@@ -12,15 +12,17 @@ import kotlinx.coroutines.job
  * Implementation of [RealtimeWebsocket] using Ktor's [DefaultClientWebSocketSession].
  */
 class KtorRealtimeWebsocket(
-    private val ws: DefaultClientWebSocketSession
+    private val ws: DefaultClientWebSocketSession,
+    val vsn: RealtimeProtocolVersion
 ): RealtimeWebsocket {
 
     override val hasIncomingMessages: Boolean get() = ws.isActive
 
-    override suspend fun receive(): RealtimeMessage {
-        return ws.receiveDeserialized()
+    override suspend fun receive(): RealtimeFrame {
+        TODO("")
     }
 
+
     override suspend fun send(message: RealtimeMessage) {
         ws.sendSerialized(message)
     }

Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/websocket/RealtimeFrame.kt

@@ -0,0 +1,9 @@
+package io.github.jan.supabase.realtime.websocket
+
+sealed interface RealtimeFrame {
+
+    class Binary(val data: ByteArray)
+
+    data class Text(val text: String)
+
+}

Realtime/src/commonMain/kotlin/io/github/jan/supabase/realtime/websocket/RealtimeWebsocket.kt

@@ -16,9 +16,9 @@ interface RealtimeWebsocket {
     val hasIncomingMessages: Boolean
 
     /**
-     * Receive a message from the websocket.
+     * Receive a frame from the websocket.
      */
-    suspend fun receive(): RealtimeMessage
+    suspend fun receive(): RealtimeFrame
 
     /**
      * Send a message to the websocket.