how to use Akka http web-sockets - scala

Question

i have started using akka client websockets
i have a question regrading multiple request and response as here the document says
Note
The Flow that is returned by this method can only be materialized once. For each request a new flow must be acquired by calling the method again
and here is the sample code this example is for sending a message and printing any incoming message:
so i have a question if i have following scenario
request 1
{
"janus" : "create",
"transaction" : "123"
}
response #1
{
"janus": "success",
"transaction": "123",
"data": {
"id": 4574061985075210
}
}
and
request # 02 {
"janus": "attach","session_id":${sessionId},"plugin":"janus.plugin.echotest","transaction":"asqeasd4as3d4asdasddas"
}
response # 02 {
}
----
i need to instantiate request #2 based on response #1 so will the following code would be assumed correct ? i have a doubt becuase i am again opening web-sockets connection and according to my knowledge web-sockets connection is opened once and we send and receive messages over that connection but akka web-sockets documents does not support that (at least that is what i understood so far i maybe wrong that's why i am here )
here is my code
val source =
"""{ "janus": "create", "transaction":"d1403sa54a5s3d4as3das"}"""
val jsonAst = source.parseJson
val responseSession: Sink[Message, Future[Done]] =
Sink.foreach[Message] {
case message: TextMessage.Strict =>
println("message response " + message.text)
val strJson = message.text
val jsonResponse = strJson.parseJson
val jsonObj = jsonResponse.asJsObject
val janus = jsonObj.fields("janus").convertTo[String]
val data = jsonObj.fields("data").asJsObject
val sessionIDInt = sessionID.convertTo[BigInt]
getPluginData(sessionIDInt)//here i am repeating the code of webSocketClientFlow https://doc.akka.io/docs/akka-http/current/client-side/websocket-support.html#websocketclientflow
//is this the above approach is correct?
}
val flow: Flow[Message, Message, Promise[Option[Message]]] =
Flow.fromSinkAndSourceMat(
responseSession,
Source.single(TextMessage(jsonAst.toString())).concatMat(Source.maybe[Message])(Keep.right))(Keep.right)
val (upgradeResponse, closed) =
Http().singleWebSocketRequest(WebSocketRequest(url, Nil, Option("janus-protocol")), flow)
def getPluginData(sessionId: BigInt): Unit = {
val responsePlugin: Sink[Message, Future[Done]] =
Sink.foreach[Message] {
case message: TextMessage.Strict =>
println("plugin response " + message.text)
val strJson = message.text
val jsonResponse = strJson.parseJson
val jsonObj = jsonResponse.asJsObject
val janus = jsonObj.fields("janus").convertTo[String]
val sessionID = jsonObj.fields("session_id") .convertTo[BigInt]
val data = jsonObj.fields("data").asJsObject
val handelID = data.fields("id")
val handleIdInt = handelID.convertTo[BigInt]
//here i will call another method which has its own sink and source and the same code again ->getHandleDetails(sessionID,handleIdInt)
}
val requestPluginJson = s"""{ "janus": "attach","session_id":${sessionId},"plugin":"janus.plugin.echotest","transaction":"asqeasd4as3d4asdasddas"}"""
val jsonAstPlugin = requestPluginJson.parseJson // or JsonParser(source)
val requestPlugin = Source.single(TextMessage(jsonAstPlugin.toString()))
val webSocketFlow = Http().webSocketClientFlow(WebSocketRequest(url, Nil, Option("janus-protocol")))
val (upgradeResponse, closed) =
requestPlugin
.viaMat(webSocketFlow)(Keep.right) // keep the materialized Future[WebSocketUpgradeResponse]
.toMat(responsePlugin)(Keep.both) // also keep the Future[Done]
.run()
val connected = upgradeResponse.flatMap { upgrade =>
if (upgrade.response.status == StatusCodes.SwitchingProtocols) {
Future.successful(Done)
} else {
throw new RuntimeException(s"Connection failed: ${upgrade.response.status}")
}
}
connected.onComplete(println)
closed.foreach(_ => println("closed plugin"))
}