Fix Ping/Pong (de)serialization and response

app/src/main/java/org/unifiedpush/distributor/sunup/api/MessageSender.kt

@@ -30,6 +30,11 @@ object MessageSender {
         }
     }
 
+    fun ping(context: Context) {
+        send(context, ClientMessage.Ping)
+        ServerConnection.waitingPong.set(true)
+    }
+
     fun hasPendingMsgs(): Boolean {
         return messageQueue.isNotEmpty()
     }

app/src/main/java/org/unifiedpush/distributor/sunup/api/ServerConnection.kt

@@ -8,7 +8,7 @@ import android.util.Log
 import android.widget.Toast
 import java.util.Calendar
 import java.util.concurrent.TimeUnit
-import kotlinx.serialization.json.Json
+import java.util.concurrent.atomic.AtomicBoolean
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.Response
@@ -33,7 +33,6 @@ import org.unifiedpush.distributor.utils.removeSync
 
 class ServerConnection(private val context: Context, private val releaseLock: () -> Unit) : WebSocketListener() {
 
-    private val json = Json { ignoreUnknownKeys = true }
     private val store = AppStore(context)
 
     fun start(): WebSocket {
@@ -73,7 +72,7 @@ class ServerConnection(private val context: Context, private val releaseLock: ()
             is ServerMessage.Broadcast -> ignoreEvent()
             is ServerMessage.Hello -> onHello(ws, message)
             is ServerMessage.Notification -> onNotification(ws, message)
-            ServerMessage.Ping -> onPing()
+            ServerMessage.Ping -> onPing(ws)
             is ServerMessage.Register -> onRegister(message)
             is ServerMessage.Unegister -> onUnregister(message)
         }
@@ -119,8 +118,14 @@ class ServerConnection(private val context: Context, private val releaseLock: ()
         ).send(ws)
     }
 
-    private fun onPing() {
+    private fun onPing(ws: WebSocket) {
         FailureCounter.newPing(context)
+        if (!waitingPong.getAndSet(false)) {
+            Log.d(TAG, "Sending Pong")
+            ClientMessage.Ping.send(ws)
+        } else {
+            Log.d(TAG, "Received Pong")
+        }
     }
 
     private fun onRegister(message: ServerMessage.Register) {
@@ -201,5 +206,6 @@ class ServerConnection(private val context: Context, private val releaseLock: ()
 
     companion object {
         var lastEventDate: Calendar? = null
+        var waitingPong = AtomicBoolean(false)
     }
 }

app/src/main/java/org/unifiedpush/distributor/sunup/api/data/ClientMessage.kt

@@ -105,8 +105,15 @@ sealed class ClientMessage {
     @Serializable
     data class ClientAck(val channelID: String, val version: String)
 
-    fun send(ws: WebSocket) {
+    fun serialize(): String {
         val json = Json { ignoreUnknownKeys = true }
-        ws.send(json.encodeToString<ClientMessage>(this))
+        return when (this) {
+            Ping -> "{}"
+            else -> json.encodeToString<ClientMessage>(this)
+        }
+    }
+
+    fun send(ws: WebSocket) {
+        ws.send(this.serialize())
     }
 }

app/src/main/java/org/unifiedpush/distributor/sunup/api/data/ServerMessage.kt

@@ -3,6 +3,8 @@ package org.unifiedpush.distributor.sunup.api.data
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.JsonClassDiscriminator
 
 @OptIn(ExperimentalSerializationApi::class)
@@ -97,4 +99,19 @@ sealed class ServerMessage {
     @Serializable
     @SerialName("ping")
     data object Ping : ServerMessage()
+
+    companion object {
+        fun deserialize(jsonStr: String): ServerMessage? {
+            val json = Json { ignoreUnknownKeys = true }
+            return try {
+                json.decodeFromString<ServerMessage>(jsonStr)
+            } catch (e: SerializationException) {
+                if (json.decodeFromString<Map<String, String>>(jsonStr).isEmpty()) {
+                    Ping
+                } else {
+                    null
+                }
+            }
+        }
+    }
 }

app/src/main/java/org/unifiedpush/distributor/sunup/services/RestartWorker.kt

@@ -7,7 +7,6 @@ import android.util.Log
 import androidx.work.*
 import org.unifiedpush.distributor.WorkerCompanion
 import org.unifiedpush.distributor.sunup.api.MessageSender
-import org.unifiedpush.distributor.sunup.api.data.ClientMessage
 import org.unifiedpush.distributor.sunup.callback.NetworkCallbackFactory
 import org.unifiedpush.distributor.sunup.utils.TAG
 
@@ -20,15 +19,16 @@ class RestartWorker(ctx: Context, params: WorkerParameters) : Worker(ctx, params
     override fun doWork(): Result {
         // We avoid running twice at the same time
         synchronized(lock) {
-            Log.d(TAG, "Working")
+            Log.d(TAG, "Working [$id]")
             if (!NetworkCallbackFactory.hasInternet) {
                 Log.d(TAG, "Aborting, no internet.")
                 return Result.success()
             }
             if (FailureCounter.isRunningWithoutFailure) {
+                Log.d(TAG, "Running without failure")
                 // We send a ping, if it fails it will restart this worker, and wont
                 // pass this check
-                MessageSender.send(applicationContext, ClientMessage.Ping)
+                MessageSender.ping(applicationContext)
                 return Result.success()
             }
             Log.d(TAG, "Restarting")