refactor: add arguments support to run client or server

app/src/main/java/clientserver/App.java

@@ -1,5 +1,8 @@
 package clientserver;
 
+import clientserver.client.Client;
+import clientserver.server.ClientHandler;
+
 public class App {
 
     public String getGreeting() {
@@ -7,8 +10,28 @@ public class App {
     }
 
     public static void main(String[] args) {
-        System.out.println(new App().getGreeting());
-        ClientHandler.main(new String[] {});
-        // MistralDirectAPI.main(new String[] {});
+        if (args.length == 0) {
+            System.out.println(
+                "Please use --args='client' or --args='server'."
+            );
+            return;
+        }
+
+        String mode = args[0];
+
+        switch (mode.toLowerCase()) {
+            case "client":
+                // Run the client
+                System.out.println("Starting client...");
+                Client.main(new String[] {});
+                break;
+            case "server":
+                // Run the server
+                System.out.println("Starting server...");
+                ClientHandler.main(new String[] {});
+                break;
+            default:
+                System.out.println("Unknown mode: " + mode);
+        }
     }
 }