Duplicate nick check

src/main.rs

@@ -80,6 +80,9 @@ impl ChatServer {
         Ok(())
     }
 
+    pub fn is_nick_in_use(&self, name: &str) -> bool {
+        self.user_map.values().any(|client| { client.name == name })
+    }
 }
 
 #[derive(Debug)]
@@ -108,16 +111,23 @@ fn handle_client(mut stream: TcpStream, server: Arc<Mutex<ChatServer>>, client_i
 
     // greet and recv nick
     write!(writer, "Hello and welcome to RustChat!\nNick: ")?;
-    let nick = lines.next().ok_or(ChatError::Protocol(String::from("Could not recv nickname")))??;
-    // FIXME: check for nick name uniqueness
+    let mut nick;
+    loop {
+        nick = lines.next().ok_or(ChatError::Protocol(String::from("Could not recv nickname")))??;
+        // check for nick name uniqueness
+        let mut srv = server.lock()?;
+        if ! srv.is_nick_in_use(&nick) {
+            // print joined msg and register at server
+            srv.send_to_all(&format!("* {} has joined the chat", nick))?;
+            let curr_users = srv.get_user_count();
+            let users_in_room_msg = if curr_users == 1 { String::from("is 1 user") } else { format!("are {} users", curr_users) };
+            write!(writer, " *** {}\n *** You are known as {}. There {} in the room.\n", srv.config.greeting_msg, nick, users_in_room_msg)?;
+            *client_id = Some(srv.register(nick.clone(), writer));
 
-    // print joined msg and register at server
-    server.lock()?.send_to_all(&format!("* {} has joined the chat", nick))?;
-    let curr_users = server.lock()?.get_user_count();
-    let users_in_room_msg = if curr_users == 1 { String::from("is 1 user") } else { format!("are {} users", curr_users) };
-    write!(writer, "Welcome, {}! You can now start to chat! There {} in the room.\n", nick, users_in_room_msg)?;
-    // server.lock()?.borrow_mut().push(ChatUser::new(nick.clone(), writer));
-    *client_id = Some(server.lock()?.register(nick.clone(), writer));
+            break;
+        }
+        write!(writer, "This nickname is already in use, please choose another.\nNick: ")?;
+    }
 
     // read lines
     for line in lines {