From 10bbcdf69e319f605a43fb983e436aacf78861ed Mon Sep 17 00:00:00 2001
From: Alexander Sazonov <alexandr.sazonov@stud.unibas.ch>
Date: Sun, 27 Mar 2022 00:38:48 +0100
Subject: [PATCH] Added name duplicate handler by modifying the ClientHandler
 class as well as adding a class where all Client names are stored

---
 .../dmi/dbis/cs108/multiplayer/client/Client.java  |  4 +++-
 .../cs108/multiplayer/server/AllClientNames.java   | 14 ++++++++++++++
 .../cs108/multiplayer/server/ClientHandler.java    |  8 ++++++++
 .../{client => server}/NameGenerator.java          |  2 +-
 4 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/AllClientNames.java
 rename src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/{client => server}/NameGenerator.java (90%)

diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/client/Client.java b/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/client/Client.java
index c6c7db5..8844233 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/client/Client.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/client/Client.java
@@ -1,6 +1,7 @@
 package ch.unibas.dmi.dbis.cs108.multiplayer.client;
 
 import ch.unibas.dmi.dbis.cs108.multiplayer.protocol.NoLegalProtocolCommandStringFoundException;
+import ch.unibas.dmi.dbis.cs108.multiplayer.server.NameGenerator;
 
 import java.net.Socket;
 import java.io.*;
@@ -20,7 +21,6 @@ public class Client {
       this.out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
       this.in = new BufferedReader((new InputStreamReader((socket.getInputStream()))));
 
-      String randomUserName = NameGenerator.randomName();
       //TODO hide connecting logik(next 4 lines)
       this.userName = userName;
       this.out.write(getUsername());
@@ -147,4 +147,6 @@ public class Client {
   public String getUsername() {
     return userName;
   }
+
 }
+
diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/AllClientNames.java b/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/AllClientNames.java
new file mode 100644
index 0000000..aea8c71
--- /dev/null
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/AllClientNames.java
@@ -0,0 +1,14 @@
+package ch.unibas.dmi.dbis.cs108.multiplayer.server;
+
+/* This class is built to contain the usernames of all players in a single string.
+* This allows a duplicate check (--> ClientHandler) when a new player chooses
+* a name: does the string with all the previous names contain the new player's
+* desired username? If yes, he is being assigned a random name. If no, he can keep
+* his desired name. */
+
+public class AllClientNames {
+    static StringBuilder names = new StringBuilder();
+    public static String allNames(String currentName) {
+        return names.append(currentName).toString();
+    }
+}
diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/ClientHandler.java b/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/ClientHandler.java
index 5ffa196..657eb6c 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/ClientHandler.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/ClientHandler.java
@@ -28,6 +28,14 @@ public class ClientHandler implements Runnable  {
             this.out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
             this.in = new BufferedReader((new InputStreamReader((socket.getInputStream()))));
             this.clientUserName = in.readLine();
+
+            // duplicate handling: if username already taken, assign random name to client
+            if (AllClientNames.allNames("").contains(clientUserName)) {
+                clientUserName = NameGenerator.randomName();
+            }
+            // add username to list of all client names for future duplicate checking
+            AllClientNames.allNames(clientUserName);
+
             connectedClients.add(this);
             broadcastMessage("SERVER: " + clientUserName + " has joined the Server");
         } catch (IOException e) {
diff --git a/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/client/NameGenerator.java b/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/NameGenerator.java
similarity index 90%
rename from src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/client/NameGenerator.java
rename to src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/NameGenerator.java
index 7ec6886..2739cf7 100644
--- a/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/client/NameGenerator.java
+++ b/src/main/java/ch/unibas/dmi/dbis/cs108/multiplayer/server/NameGenerator.java
@@ -1,4 +1,4 @@
-package ch.unibas.dmi.dbis.cs108.multiplayer.client;
+package ch.unibas.dmi.dbis.cs108.multiplayer.server;
 
 import java.util.Random;