feat: implemented handshake and sendMessage methods properly

Server/src/main/java/uulm/teamname/marvelous/server/netconnector/MarvelousServer.java

@@ -39,9 +39,9 @@ public class MarvelousServer extends WebSocketServer {
 
     private final UserManager userManager;
 
-    public MarvelousServer(InetSocketAddress address, JSON json) {
+    public MarvelousServer(InetSocketAddress address) {
         super(address);
-        this.userManager = new UserManager(json);
+        this.userManager = new UserManager();
     }
 
     /** Practically No-Arg constructor for testing. <b>NEVER USE ANYWHERE ELSE!</b>

Server/src/main/java/uulm/teamname/marvelous/server/netconnector/UserManager.java

@@ -3,8 +3,11 @@ package uulm.teamname.marvelous.server.netconnector;
 import org.tinylog.Logger;
 import uulm.teamname.marvelous.gamelibrary.json.JSON;
 import uulm.teamname.marvelous.gamelibrary.json.ValidationUtility;
+import uulm.teamname.marvelous.gamelibrary.messages.BasicMessage;
 import uulm.teamname.marvelous.gamelibrary.messages.ErrorMessage;
 import uulm.teamname.marvelous.gamelibrary.messages.client.*;
+import uulm.teamname.marvelous.gamelibrary.messages.server.HelloClientMessage;
+import uulm.teamname.marvelous.server.Server;
 import uulm.teamname.marvelous.server.lobbymanager.Participant;
 
 import org.java_websocket.WebSocket;
@@ -42,13 +45,13 @@ public class UserManager {
     private final JSON json;
 
     /** Constructs a new, empty UserManager */
-    public UserManager(JSON json) {
+    public UserManager() {
         this.newUsers = new HashSet<>();
         this.readyToConnect = new HashMap<>();
         this.readyToReconnect = new HashMap<>();
         this.inGame = new HashMap<>();
         this.activeParticipants = new HashMap<>();
-        this.json = json;
+        this.json = new JSON(Server.getCharacterConfig());
     }
 
     /** Called on a new WebSocket connection. Places the WebSocket and its ResourceDescriptor in a HashMap. */
@@ -100,7 +103,7 @@ public class UserManager {
         }
     }
 
-    void handshake(WebSocket conn, HelloServerMessage message) {
+    void handshake(WebSocket conn, HelloServerMessage message) { // TODO: Send helloClient
         if (!newUsers.contains(conn)) {
             Logger.debug("websocket {} sent HelloServerMessage outside of handshake", conn);
             sendError(conn, "Invalid message, as Handshake is already completed");
@@ -109,6 +112,8 @@ public class UserManager {
 
         Logger.info("Performing handshake with user '{}'", message.name);
 
+        var answer = new HelloClientMessage();
+
         SUID clientID = new SUID(message.name, message.deviceID);
 
         // check if client is reconnected
@@ -117,6 +122,7 @@ public class UserManager {
             synchronized (readyToReconnect) {
                 readyToReconnect.put(conn, clientID);
             }
+            answer.runningGame = true;
         } else {
             Logger.trace("removing handshaking user from newUsers");
             synchronized (newUsers) {
@@ -126,7 +132,10 @@ public class UserManager {
             synchronized (readyToConnect) {
                 readyToConnect.put(conn, clientID);
             }
+            answer.runningGame = false;
         }
+        // Send the answer message with the previously set runningGame
+        sendMessage(conn, answer);
     }
 
     void reconnectClient(WebSocket conn, ReconnectMessage message) {
@@ -154,6 +163,7 @@ public class UserManager {
     }
 
     void assignLobby(WebSocket conn, PlayerReadyMessage message) {
+        // TODO: Assign a lobby
     }
 
     void charactersSelected(WebSocket conn, CharacterSelectionMessage message) {
@@ -162,12 +172,21 @@ public class UserManager {
     void relayRequestMessage(Participant conn, RequestMessage message) {
     }
 
+    public void sendMessage(WebSocket conn, BasicMessage message) {
+        var jsonRepresentingMessage = json.stringify(message);
+        if (jsonRepresentingMessage.isEmpty()) {
+            Logger.warn("Message {} could not be serialized!", message);
+        } else {
+            conn.send(jsonRepresentingMessage.get());
+        }
+    }
+
     /** Sends an {@link uulm.teamname.marvelous.gamelibrary.messages.ErrorMessage} to the specified user. */
     public void sendError(WebSocket conn, String error) {
         Logger.debug("Sending error message '{}' to WebSocket {}", error, conn);
         var errorMessage = new ErrorMessage();
         errorMessage.message = error;
-        conn.send(json.stringify(errorMessage).get());
+        sendMessage(conn, errorMessage);
     }
 
     public void disconnectUser(WebSocket conn, boolean closedByRemote) {