Implement chat room backend

7 files changed, 96 insertions, 20 deletions

diff --git a/client/src/main/scala/chat/Main.scala b/client/src/main/scala/chat/Main.scala
index c68e0d9..dbc2876 100644
--- a/client/src/main/scala/chat/Main.scala
+++ b/client/src/main/scala/chat/Main.scala
@@ -1,26 +1,22 @@
 package chat
 
+import scala.scalajs.concurrent.JSExecutionContext.Implicits.queue
 import scala.scalajs.js
 
 import org.scalajs.dom
-import scala.util.{ Failure, Success }
-import scala.scalajs.concurrent.JSExecutionContext.Implicits.queue
+import org.scalajs.dom.raw.MessageEvent
 import upickle.default._
 
 object Main extends js.JSApp {
 
   def main(): Unit = {
     val root = dom.document.getElementById("root")
+    val sock = new dom.WebSocket("ws://localhost:9000/socket/john")
 
-    dom.ext.Ajax.get("/message").onComplete {
-      case Success(msg) if 200 <= msg.status && msg.status < 300 =>
-        root.textContent = "OK, " + read[Message](msg.responseText).data
-      case Success(msg) =>
-        root.textContent = msg.responseText
-      case Failure(err) =>
-        root.textContent = "ERROR: " + err
+    sock.onmessage = (msg: MessageEvent) => {
+      val event = read[Event](msg.data.asInstanceOf[String])
+      dom.console.log(event.toString())
     }
-    //dom.document.getElementById("scalajsShoutOut").textContent = SharedMessages.itWorks
   }
 
 }
diff --git a/server/app/controllers/HomeController.scala b/server/app/controllers/HomeController.scala
index 13bc8dc..4d48c98 100644
--- a/server/app/controllers/HomeController.scala
+++ b/server/app/controllers/HomeController.scala
@@ -1,14 +1,24 @@
 package controllers
 
-import play.api._
+import akka.actor.{ActorRef, ActorSystem, Props}
+import akka.stream.Materializer
+import chat._
+import javax.inject._
+import play.api.libs.streams.ActorFlow
 import play.api.mvc._
+import play.api.mvc.WebSocket.MessageFlowTransformer
 import upickle.default._
 
 /**
  * This controller creates an `Action` to handle HTTP requests to the
  * application's home page.
  */
-class HomeController extends Controller {
+class HomeController @Inject() (
+  implicit system: ActorSystem,
+  mat: Materializer
+) extends Controller {
+
+  lazy val room: ActorRef = system.actorOf(Props(classOf[RoomActor]))
 
   /**
    * Create an Action to render an HTML page.
@@ -21,8 +31,13 @@ class HomeController extends Controller {
     Ok(views.html.index())
   }
 
-  def message = Action { implicit request =>
-    Ok(write(chat.Message("hello")))
+  def socket(uid: String) = WebSocket.accept[Command, Event] { request =>
+    ActorFlow.actorRef(out => Props(classOf[ClientActor], uid, room, out))
   }
 
+  implicit val transformer = MessageFlowTransformer.stringMessageFlowTransformer.map(
+    in => read[Command](in),
+    (out: Event) => write(out)
+  )
+
 }
diff --git a/server/app/controllers/actors.scala b/server/app/controllers/actors.scala
new file mode 100644
index 0000000..f10f925
--- /dev/null
+++ b/server/app/controllers/actors.scala
@@ -0,0 +1,56 @@
+package controllers
+
+import akka.actor.{ Actor, ActorRef, Terminated }
+import chat._
+import scala.collection.mutable.HashMap
+
+
+/** An actor instantiated for every websocket connection. It represents a
+  * chat client and registers with a chat room.
+  * @param uid user id of the connecting client
+  * @param room chat room actor that this client will join
+  * @param socket websocket actor, any message sent to it will get transferred to the remote
+  * browser
+  */
+class ClientActor(uid: String, room: ActorRef, socket: ActorRef) extends Actor {
+
+  override def preStart() = {
+    room ! (self, uid)
+  }
+
+  def receive = {
+    case cmd: Command => room ! cmd
+    case ev: Event => socket ! ev
+  }
+
+}
+
+/** An actor that represents a chat room.
+  * Handles commands and events subclassing `chat.Command` and `chat.Event`
+  */
+class RoomActor extends Actor {
+  val clients = new HashMap[ActorRef, String]
+
+  override def receive = {
+
+    case (client: ActorRef, uid: String) =>
+      context.watch(sender)
+      clients += client -> uid
+      for ( (client, _) <- clients ) {
+        client ! Joined(uid)
+      }
+
+    case Terminated(client) =>
+      clients -= client
+      for ( (cl, _) <- clients ) {
+        cl ! Left(clients(client))
+      }
+
+    case Broadcast(content) =>
+      val origin = clients(sender)
+      for ( (client, _) <- clients ) {
+        client ! Message(origin, content)
+      }
+  }
+}
+
diff --git a/server/app/views/index.scala.html b/server/app/views/index.scala.html
index 911bdaf..4b71c59 100644
--- a/server/app/views/index.scala.html
+++ b/server/app/views/index.scala.html
@@ -1,7 +1,9 @@
 @()
 
-@main("Welcome to Play") {
-    <main id="root">placeholder</main>
+@main("Welcome to Chat") {
+    <main id="root">
+	hello
+    </main>
     <script src="@routes.Assets.versioned("client-fastopt.js")" type="text/javascript"></script>
     <script type="text/javascript">
      chat.Main().main()
diff --git a/server/conf/routes b/server/conf/routes
index ca64d25..ab400c7 100644
--- a/server/conf/routes
+++ b/server/conf/routes
@@ -5,7 +5,7 @@
 
 # An example controller showing a sample home page
 GET     /                           controllers.HomeController.index
-GET     /message		    controllers.HomeController.message
+GET     /socket/:uid		    controllers.HomeController.socket(uid)
 
 # Map static resources from the /public folder to the /assets URL path
 GET     /assets/*file               controllers.Assets.versioned(path="/public", file: Asset)
diff --git a/shared/src/main/scala/chat/Messages.scala b/shared/src/main/scala/chat/Messages.scala
deleted file mode 100644
index deff8eb..0000000
--- a/shared/src/main/scala/chat/Messages.scala
+++ /dev/null
@@ -1,3 +0,0 @@
-package chat
-
-case class Message(data: String)
diff --git a/shared/src/main/scala/chat/messages.scala b/shared/src/main/scala/chat/messages.scala
new file mode 100644
index 0000000..a27631e
--- /dev/null
+++ b/shared/src/main/scala/chat/messages.scala
@@ -0,0 +1,10 @@
+package chat
+
+sealed trait Command // message to chat server
+sealed trait Event // message from chat server
+
+case class Broadcast(content: String) extends Command
+
+case class Joined(uid: String) extends Event
+case class Left(uid: String) extends Event
+case class Message(uid: String, content: String) extends Event