Fix/udp discovery

src/main/java/com/auction/client/controllers/AuctionDetailController.java

@@ -50,7 +50,7 @@ public void loadAuction(int auctionId) {
         this.currentAuctionId = auctionId;
         try {
             var service = ClientContext.getInstance().getRmiProvider().getService();
-            this.pollingService = new PollingService(service);
+            this.pollingService = new PollingService();
             // load initial item state
             AuctionItem initial = service.getAuctionById(auctionId);
             this.currentItem = initial;
@@ -60,10 +60,21 @@ public void loadAuction(int auctionId) {
             loadDetailThumbnail(auctionId, 1, thumb1View);
             loadDetailThumbnail(auctionId, 2, thumb2View);
             loadDetailThumbnail(auctionId, 3, thumb3View);
-            pollingService.startPolling(auctionId, item -> {
-                this.currentItem = item;
-                Platform.runLater(() -> updateUi(item));
-            });
+            pollingService.startPolling(() -> {
+                try {
+                    AuctionItem item = service.getAuctionById(auctionId);
+                    if (item != null && currentItem != null) {
+                        String oldEnd = currentItem.getEndTime();
+                        if (oldEnd != null && !oldEnd.equals(item.getEndTime())) {
+                            Platform.runLater(() -> showToast("Timer Extended!"));
+                        }
+                    }
+                    this.currentItem = item;
+                    Platform.runLater(() -> updateUi(item));
+                } catch (Exception e) {
+                    throw new RuntimeException(e);
+                }
+            }, 2);
         } catch (Exception e) {
             e.printStackTrace();
         }
@@ -180,6 +191,7 @@ private void handlePlaceBid() {
                 Platform.runLater(() -> {
                     updateUi(currentItem);
                     bidStatusLabel.setText("Failed: " + finalMsg);
+                    animateShakeError();
                 });
             } finally {
                 Platform.runLater(() -> {
@@ -191,6 +203,17 @@ private void handlePlaceBid() {
         }, executor);
     }
 
+    private void animateShakeError() {
+        if (bidAmountField == null) return;
+        bidAmountField.setStyle("-fx-border-color: #f85149; -fx-border-width: 2px;");
+        javafx.animation.TranslateTransition tt = new javafx.animation.TranslateTransition(Duration.millis(50), bidAmountField);
+        tt.setByX(10f);
+        tt.setCycleCount(6);
+        tt.setAutoReverse(true);
+        tt.setOnFinished(e -> bidAmountField.setStyle(""));
+        tt.play();
+    }
+
     private void loadDetailThumbnail(int auctionId, int index, javafx.scene.image.ImageView target) {
         java.util.concurrent.CompletableFuture.supplyAsync(() -> {
             try {

src/main/java/com/auction/client/controllers/ConnectController.java

@@ -55,32 +55,63 @@ public void initialize() {
 
     @FXML
     private void handleConnect() {
-        String host = ipField.getText();
-        if (host == null || host.trim().isEmpty()) {
-            host = "localhost";
-        }
+        String hostInput = ipField.getText();
+        String portInput = portField.getText();
+
+        String host = (hostInput == null || hostInput.trim().isEmpty()) ? "localhost" : hostInput.trim();
         int port = 1099;
-        try {
-            String portStr = portField.getText();
-            if (portStr != null && !portStr.trim().isEmpty()) {
-                port = Integer.parseInt(portStr);
+        if (portInput != null && !portInput.trim().isEmpty()) {
+            try {
+                port = Integer.parseInt(portInput.trim());
+            } catch (NumberFormatException e) {
+                statusLabel.setText("Invalid port number.");
+                return;
             }
-        } catch (NumberFormatException e) {
-            statusLabel.setText("Invalid port number.");
-            return;
         }
 
-        try {
-            com.auction.client.core.ClientContext context = com.auction.client.core.ClientContext.getInstance();
-            context.getRmiProvider().connect(host, port);
-            statusLabel.setText("Connected successfully!");
-            context.getUdpClient().stopListening();
-
-            // Navigate to login
-            context.getViewLoader().loadView("login.fxml");
-        } catch (Exception e) {
-            statusLabel.setText("Connection failed: " + e.getMessage());
-            e.printStackTrace();
-        }
+        statusLabel.setText("Connecting to " + host + ":" + port + "...");
+
+        final String finalHost = host;
+        final int finalPort = port;
+
+        // Set short timeout for RMI connection attempts
+        System.setProperty("sun.rmi.transport.tcp.connectTimeout", "3000");
+
+        // Use a standard Thread to avoid any issues with common pool size or configuration
+        new Thread(() -> {
+            try {
+                com.auction.client.core.ClientContext context = com.auction.client.core.ClientContext.getInstance();
+                // Perform the RMI connection and health check
+                context.getRmiProvider().connect(finalHost, finalPort);
+
+                javafx.application.Platform.runLater(() -> {
+                    try {
+                        statusLabel.setText("Connected successfully!");
+                        context.getUdpClient().stopListening();
+                        // Navigate to login
+                        context.getViewLoader().loadView("login.fxml");
+                    } catch (Exception e) {
+                        statusLabel.setText("Navigation failed: " + e.getMessage());
+                    }
+                });
+            } catch (Exception e) {
+                javafx.application.Platform.runLater(() -> {
+                    Throwable root = e;
+                    while (root.getCause() != null && root.getCause() != root) {
+                        root = root.getCause();
+                    }
+
+                    String errorMsg;
+                    if (root instanceof java.net.ConnectException || root instanceof java.rmi.ConnectException) {
+                        errorMsg = "Server unreachable at " + finalHost + ":" + finalPort;
+                    } else if (e instanceof java.rmi.NotBoundException) {
+                        errorMsg = "RTDAS service not found on this server.";
+                    } else {
+                        errorMsg = (root.getMessage() != null) ? root.getMessage() : root.toString();
+                    }
+                    statusLabel.setText("Connection failed: " + errorMsg);
+                });
+            }
+        }).start();
     }
 }

src/main/java/com/auction/client/controllers/GalleryController.java

@@ -30,11 +30,26 @@ public class GalleryController {
     private static final Image PLACEHOLDER_IMAGE = loadPlaceholderImage();
     private java.util.List<AuctionItem> allAuctions = java.util.List.of();
 
+    private com.auction.client.service.PollingService pollingService;
+
     @FXML
     public void initialize() {
         try {
             var context = ClientContext.getInstance();
             var service = context.getRmiProvider().getService();
+
+            pollingService = new com.auction.client.service.PollingService();
+            pollingService.startPolling(() -> {
+                try {
+                    List<AuctionItem> items = service.getActiveAuctions();
+                    allAuctions = (items == null) ? java.util.List.of() : items;
+                    Platform.runLater(() -> handleSearch()); // handleSearch applies current filter/sort
+                } catch (Exception e) {
+                    throw new RuntimeException(e);
+                }
+            }, 2);
+
+            // initial load
             List<AuctionItem> items = service.getActiveAuctions();
             allAuctions = (items == null) ? java.util.List.of() : items;
             Platform.runLater(() -> renderAuctions(allAuctions));
@@ -216,6 +231,7 @@ private static Image loadPlaceholderImage() {
     @FXML
     private void handleBackToDashboard() {
         try {
+            if (pollingService != null) pollingService.shutdown();
             ClientContext context = ClientContext.getInstance();
             String targetView = context.getPreviousViewName();
             if (targetView == null || targetView.isBlank()) {
@@ -226,4 +242,22 @@ private void handleBackToDashboard() {
             e.printStackTrace();
         }
     }
+
+    // Also shutdown before going to detail view
+    private void loadDetailView(AuctionItem item, int index) {
+        try {
+            if (pollingService != null) pollingService.shutdown();
+            ClientContext context = ClientContext.getInstance();
+            context.setPreviousViewName("gallery.fxml");
+            Object ctrl = context.getViewLoader().loadView("auction_detail.fxml");
+            if (ctrl instanceof AuctionDetailController) {
+                ((AuctionDetailController) ctrl).loadAuction(item.getId());
+                if (index >= 0) {
+                    ((AuctionDetailController) ctrl).showHeroImageIndex(index);
+                }
+            }
+        } catch (IOException ex) {
+            ex.printStackTrace();
+        }
+    }
 }

src/main/java/com/auction/client/controllers/UserDashboardController.java

@@ -60,8 +60,14 @@ public class UserDashboardController {
 
   private byte[] img1Bytes, img2Bytes, img3Bytes;
 
+  private com.auction.client.service.PollingService pollingService;
+
   @FXML
   public void initialize() {
+    pollingService = new com.auction.client.service.PollingService();
+    pollingService.startPolling(() -> {
+      javafx.application.Platform.runLater(() -> refreshDashboard());
+    }, 2);
     refreshDashboard();
   }
 
@@ -116,6 +122,7 @@ private void handleRefreshDashboard() {
   @FXML
   private void handleOpenGallery() {
     try {
+      if (pollingService != null) pollingService.shutdown();
       com.auction.client.core.ClientContext context =
         com.auction.client.core.ClientContext.getInstance();
       context.setPreviousViewName("user_dashboard.fxml");
@@ -139,6 +146,7 @@ private void handleOpenAuctionDetail() {
 
     if (selected != null) {
         try {
+          if (pollingService != null) pollingService.shutdown();
           com.auction.client.core.ClientContext context = com.auction.client.core.ClientContext.getInstance();
           context.setCurrentAuctionId(selected.getId());
           context.setPreviousViewName("user_dashboard.fxml");

src/main/java/com/auction/client/network/RmiClientProvider.java

@@ -25,6 +25,21 @@ public class RmiClientProvider {
     public IAuctionService connect(String host, int port) throws RemoteException, NotBoundException {
         Registry registry = LocateRegistry.getRegistry(host, port);
         service = (IAuctionService) registry.lookup(Constants.RMI_SERVICE_NAME);
+
+        // Health check
+        service.serverTime();
+
+        // Persist last server
+        try {
+            java.nio.file.Path dir = java.nio.file.Paths.get(System.getProperty("user.home"), ".rtdas");
+            if (!java.nio.file.Files.exists(dir)) {
+                java.nio.file.Files.createDirectories(dir);
+            }
+            java.nio.file.Files.writeString(dir.resolve("last_server"), host + ":" + port);
+        } catch (java.io.IOException e) {
+            System.err.println("Failed to persist last_server: " + e.getMessage());
+        }
+
         return service;
     }
 

src/main/java/com/auction/client/network/UdpDiscoveryClient.java

@@ -31,29 +31,36 @@ public void startListening() {
         if (running) return;
         running = true;
         listenerThread = new Thread(() -> {
-            try (DatagramSocket socket = new DatagramSocket(Constants.UDP_BROADCAST_PORT)) {
-                socket.setSoTimeout(1000); // 1 second timeout to allow interrupt checking
-                byte[] buffer = new byte[1024];
-                while (running) {
-                    try {
-                        DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
-                        socket.receive(packet);
-                        String data = new String(packet.getData(), 0, packet.getLength()).trim();
-                        // Format: RTDAS|<ServerName>|<RmiPort>
-                        if (data.startsWith(Constants.UDP_PREFIX + "|")) {
-                            String[] parts = data.split("\\|");
-                            if (parts.length == 3) {
-                                String serverName = parts[1];
-                                int rmiPort = Integer.parseInt(parts[2]);
-                                String host = packet.getAddress().getHostAddress();
-                                ServerInfo info = new ServerInfo(serverName, host, rmiPort);
-                                if (!discoveredServers.contains(info)) {
-                                    discoveredServers.add(info);
+            try {
+                java.net.DatagramSocket socket = new java.net.DatagramSocket(null);
+                socket.setReuseAddress(true);
+                socket.bind(new java.net.InetSocketAddress(com.auction.shared.Constants.UDP_BROADCAST_PORT));
+
+                try (socket) {
+                    socket.setSoTimeout(1000); // 1 second timeout to allow interrupt checking
+                    byte[] buffer = new byte[1024];
+                    while (running) {
+                        try {
+                            java.net.DatagramPacket packet = new java.net.DatagramPacket(buffer, buffer.length);
+                            socket.receive(packet);
+                            String data = new String(packet.getData(), 0, packet.getLength()).trim();
+                            // Format: RTDAS|v1|<rmiPort>|<serverName>|<serverId>|<rmiHost>
+                            if (data.startsWith(com.auction.shared.Constants.UDP_PREFIX + "|v1|")) {
+                                String[] parts = data.split("\\|");
+                                if (parts.length >= 6) {
+                                    int rmiPort = Integer.parseInt(parts[2]);
+                                    String serverName = parts[3];
+                                    String rmiHost = parts[5];
+                                    String host = (rmiHost != null && !rmiHost.trim().isEmpty()) ? rmiHost : packet.getAddress().getHostAddress();
+                                    ServerInfo info = new ServerInfo(serverName, host, rmiPort);
+                                    if (!discoveredServers.contains(info)) {
+                                        discoveredServers.add(info);
+                                    }
                                 }
                             }
+                        } catch (java.net.SocketTimeoutException e) {
+                            // Expected timeout, loop continues and checks running flag
                         }
-                    } catch (java.net.SocketTimeoutException e) {
-                        // Expected timeout, loop continues and checks running flag
                     }
                 }
             } catch (Exception e) {

src/main/java/com/auction/client/service/PollingService.java

@@ -15,33 +15,38 @@
  */
 public class PollingService {
 
-    private final IAuctionService service;
     private ScheduledExecutorService scheduler;
+    private int failureCount = 0;
 
-    public PollingService(IAuctionService service) {
-        this.service = service;
+    public PollingService() {
+        // generic service
     }
 
     /**
-     * Start polling a specific auction for updates.
-     * @param auctionId auction to watch
-     * @param onUpdate callback with updated AuctionItem (called on background thread)
+     * Start polling a generic task.
+     * @param task the RMI call to execute
+     * @param intervalSeconds polling interval
      */
-    public void startPolling(int auctionId, Consumer<AuctionItem> onUpdate) {
-        // TODO: schedule getAuctionById every 2s, call onUpdate with result
+    public void startPolling(Runnable task, int intervalSeconds) {
         scheduler = Executors.newSingleThreadScheduledExecutor();
         scheduler.scheduleAtFixedRate(() -> {
-            try{
-                AuctionItem item = service.getAuctionById(auctionId);
-                onUpdate.accept(item);
-            } catch(Exception e){
-                System.err.println(e.getMessage());
-                e.printStackTrace();
+            try {
+                task.run();
+                failureCount = 0; // reset on success
+            } catch (Exception e) {
+                failureCount++;
+                System.err.println("Polling failed (" + failureCount + "): " + e.getMessage());
+                if (failureCount >= 3) {
+                    shutdown();
+                    javafx.application.Platform.runLater(() -> {
+                        com.auction.client.core.ClientContext.getInstance().handleConnectionLost();
+                    });
+                }
             }
-        }, 0, 2, TimeUnit.SECONDS);
+        }, 0, intervalSeconds, TimeUnit.SECONDS);
     }
 
-    /** Stop all polling. Call when leaving the detail view. */
+    /** Stop all polling. Call when leaving the view. */
     public void shutdown() {
         if (scheduler != null && !scheduler.isShutdown()) {
             scheduler.shutdownNow();

src/main/java/com/auction/server/core/AdminManager.java

@@ -47,11 +47,15 @@ public List<String> getAuditLogs(int lastNLines, SessionContext context) throws
     }
 
     public List<User> getAllUsers(SessionContext context) {
-        return userRepo.findAllUsers();
+        return userRepo.findAllUsers().stream()
+            .map(u -> new User(u.getUsername(), null, u.getRoleType(), u.getCreatedAt()))
+            .toList();
     }
 
     public List<User> searchUsers(String query, SessionContext context) {
-        return userRepo.searchUsers(query);
+        return userRepo.searchUsers(query).stream()
+            .map(u -> new User(u.getUsername(), null, u.getRoleType(), u.getCreatedAt()))
+            .toList();
     }
 
     public void promoteUserToAdmin(String username, SessionContext context) throws AuctionException {