Added a new Couldnt connect to server error message

Re wrote the URL parsing logic again, but due to increased complexity put it into a utility class
Fixed desktop version opening up a lobby even when it did not connect to a server
Wired up the new error message to mobile, and both error messages to Desktop

forge-gui-desktop/src/main/java/forge/screens/home/online/CSubmenuOnlineLobby.java

@@ -3,6 +3,7 @@ package forge.screens.home.online;
 import java.net.BindException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
 import javax.swing.JMenu;
 import javax.swing.SwingUtilities;
@@ -16,12 +17,14 @@ import forge.gui.error.BugReporter;
 import forge.gui.framework.EDocID;
 import forge.gui.framework.ICDoc;
 import forge.gui.util.SOptionPane;
+import forge.localinstance.properties.ForgeConstants;
 import forge.menus.IMenuProvider;
 import forge.menus.MenuUtil;
 import forge.screens.home.CHomeUI;
 import forge.screens.home.CLobby;
 import forge.screens.home.VLobby;
 import forge.screens.home.sanctioned.ConstructedGameMenu;
+import forge.toolbox.FOptionPane;
 import forge.util.Localizer;
 
 public enum CSubmenuOnlineLobby implements ICDoc, IMenuProvider {
@@ -39,7 +42,7 @@ public enum CSubmenuOnlineLobby implements ICDoc, IMenuProvider {
         if (url == null) { return; }
 
         FThreads.invokeInBackgroundThread(() -> {
-            if (url.length() > 0) {
+            if (!url.isEmpty()) {
                 join(url);
             }
             else {
@@ -83,16 +86,23 @@ public enum CSubmenuOnlineLobby implements ICDoc, IMenuProvider {
         });
 
         final ChatMessage result = NetConnectUtil.join(url, VSubmenuOnlineLobby.SINGLETON_INSTANCE, FNetOverlay.SINGLETON_INSTANCE);
-
+        if(Objects.equals(result.getMessage(), ForgeConstants.CLOSE_CONN_COMMAND)) {
-        SwingUtilities.invokeLater(() -> {
+            FOptionPane.showErrorDialog(Localizer.getInstance().getMessage("UnableConnectToServer", url));
             SOverlayUtils.hideOverlay();
-            if (result instanceof ChatMessage) {
+        } else if (Objects.equals(result.getMessage(), ForgeConstants.INVALID_HOST_COMMAND)) {
-                FNetOverlay.SINGLETON_INSTANCE.show(result);
+            FOptionPane.showErrorDialog(Localizer.getInstance().getMessage("lblDetectedInvalidHostAddress", url));
-                if (CHomeUI.SINGLETON_INSTANCE.getCurrentDocID() == EDocID.HOME_NETWORK) {
+            SOverlayUtils.hideOverlay();
-                    VSubmenuOnlineLobby.SINGLETON_INSTANCE.populate();
+        } else {
+            SwingUtilities.invokeLater(() -> {
+                SOverlayUtils.hideOverlay();
+                if (result instanceof ChatMessage) {
+                    FNetOverlay.SINGLETON_INSTANCE.show(result);
+                    if (CHomeUI.SINGLETON_INSTANCE.getCurrentDocID() == EDocID.HOME_NETWORK) {
+                        VSubmenuOnlineLobby.SINGLETON_INSTANCE.populate();
+                    }
                 }
-            }
+            });
-        });
+        }
     }
 
     @Override

forge-gui-mobile/src/forge/screens/online/OnlineLobbyScreen.java

@@ -108,6 +108,9 @@ public class OnlineLobbyScreen extends LobbyScreen implements IOnlineLobby {
                         if (joinServer) {
                             result[0] = NetConnectUtil.join(url, OnlineLobbyScreen.this, chatInterface);
                             if (result[0].getMessage() == ForgeConstants.CLOSE_CONN_COMMAND) { //this message is returned via netconnectutil on exception
+                                closeConn(Forge.getLocalizer().getMessage("UnableConnectToServer", url));
+                                return;
+                            } else if (result[0].getMessage() == ForgeConstants.INVALID_HOST_COMMAND) {
                                 closeConn(Forge.getLocalizer().getMessage("lblDetectedInvalidHostAddress", url));
                                 return;
                             }

forge-gui/res/languages/de-DE.properties

@@ -281,6 +281,7 @@ OKresetWorkshopLayout=Workshop-Layout wurde zurückgesetzt.
 AresetMatchScreenLayout=Dies wird das Spielfeldlayout zurücksetzen.\nFalls du vorher noch das derzeitige Layout speichern möchtest, nutze bitte Forge->Layout->File->Save Current Layout in einem laufenden Spiel.\n\nSpielfeldlayout zurücksetzen?
 TresetMatchScreenLayout=Spielfeldlayout zurücksetzen
 OKresetMatchScreenLayout=Spielfeldlayout wurde zurückgesetzt.
+UnableConnectToServer=Unable to connect to server with host {0}.
 #EMenuGroup.java
 lblSanctionedFormats=Gültige Spielformate
 lblOnlineMultiplayer=Mehrspieler (online)

forge-gui/res/languages/en-US.properties

@@ -283,6 +283,7 @@ OKresetWorkshopLayout=Workshop layout has been reset.
 AresetMatchScreenLayout=This will reset the layout of the Match screen.\n If you want to save the current layout first, please use the Dock tab -> Save Layout option in the Match screen.\n\n Reset layout?
 TresetMatchScreenLayout=Reset Match Screen Layout
 OKresetMatchScreenLayout=Match Screen layout has been reset.
+UnableConnectToServer=Unable to connect to server with host {0}.
 #EMenuGroup.java
 lblSanctionedFormats=Sanctioned Formats
 lblOnlineMultiplayer=Online Multiplayer

forge-gui/res/languages/es-ES.properties

@@ -283,6 +283,7 @@ OKresetWorkshopLayout=El diseño del taller se ha restablecido.
 AresetMatchScreenLayout=Esto restablecerá el diseño de la pantalla de juego.\n Si desea guardar primero el diseño actual, use la pestaña Dock -> Guardar opción de diseño en la pantalla de Juego\n \n ¿Restablecer diseño?
 TresetMatchScreenLayout=Restablecer diseño de pantalla de juego
 OKresetMatchScreenLayout=El diseño de la pantalla de juego se ha restablecido.
+UnableConnectToServer=Unable to connect to server with host {0}.
 #EMenuGroup.java
 lblSanctionedFormats=Formatos oficiales
 lblOnlineMultiplayer=Multijugador online

forge-gui/res/languages/fr-FR.properties

@@ -281,6 +281,7 @@ OKresetWorkshopLayout=La disposition de l'atelier a été réinitialisée.
 AresetMatchScreenLayout=Ceci réinitialisera la mise en page de l'écran Match.\n Si vous souhaitez d'abord enregistrer la mise en page actuelle, veuillez utiliser l'onglet Dock -> Enregistrer la mise en page dans l'écran Match.\n\n Réinitialiser la mise en page ?
 TresetMatchScreenLayout=Réinitialiser la disposition de l'écran de correspondance
 OKresetMatchScreenLayout=La disposition de l'écran de correspondance a été réinitialisée.
+UnableConnectToServer=Unable to connect to server with host {0}.
 #EMenuGroup.java
 lblSanctionedFormats=Formats autorisés
 lblOnlineMultiplayer=Multijoueur en ligne

forge-gui/res/languages/it-IT.properties

@@ -280,6 +280,7 @@ OKresetWorkshopLayout=Il layout dell'officina è stato ripristinato.
 AresetMatchScreenLayout=Ciò ripristinerà il layout della schermata degli incontri. \n Se si desidera prima salvare il layout corrente, utilizzare la scheda Comandi -> opzione Salva layout della schermata di gioco. \n \n Ripristinare layout?
 TresetMatchScreenLayout=Ripristina il layout della schermata degli incontri
 OKresetMatchScreenLayout=Il layout della schermata degli incontri è stato ripristinato.
+UnableConnectToServer=Unable to connect to server with host {0}.
 #EMenuGroup.java
 lblSanctionedFormats=Formati sanzionati
 lblOnlineMultiplayer=Multigiocatore online

forge-gui/res/languages/ja-JP.properties

@@ -281,6 +281,7 @@ OKresetWorkshopLayout=ワークショップレイアウトのリセットされ
 AresetMatchScreenLayout=これにより、試合画面のレイアウトがリセットされます。\n 現在のレイアウトを最初に保存する場合は、[Dock]タブ-> [レイアウトの保存]オプションを[一致]画面で使用してください。\n\n レイアウトをリセットしますか？
 TresetMatchScreenLayout=試合画面レイアウトのリセット
 OKresetMatchScreenLayout=試合画面のレイアウトがリセットされました。
+UnableConnectToServer=Unable to connect to server with host {0}.
 #EMenuGroup.java
 lblSanctionedFormats=フォーマット
 lblOnlineMultiplayer=オンラインマルチプレイ

forge-gui/res/languages/pt-BR.properties

@@ -293,6 +293,7 @@ AresetMatchScreenLayout=Isso irá redefinir o layout da tela da Partida.\n\
  Redefinir o layout?
 TresetMatchScreenLayout=Redefinir Layout da Partida
 OKresetMatchScreenLayout=O layout da Tela da Partida foi redefinido.
+UnableConnectToServer=Unable to connect to server with host {0}.
 #EMenuGroup.java
 lblSanctionedFormats=Formatos Sancionados
 lblOnlineMultiplayer=Multijogador Online

forge-gui/res/languages/zh-CN.properties

@@ -283,6 +283,7 @@ OKresetWorkshopLayout=游戏界面已重置
 AresetMatchScreenLayout=这将重置匹配屏幕的布局。\n如果要保存当前的布局，请使用“匹配”屏幕中的“保存布局”选项。\n\n重置布局？
 TresetMatchScreenLayout=重置匹配布局
 OKresetMatchScreenLayout=匹配布局已重置。
+UnableConnectToServer=Unable to connect to server with host {0}.
 #EMenuGroup.java
 lblSanctionedFormats=单人游戏
 lblOnlineMultiplayer=多人联机

forge-gui/src/main/java/forge/gamemodes/net/NetConnectUtil.java

@@ -21,9 +21,10 @@ import forge.localinstance.properties.ForgePreferences.FPref;
 import forge.model.FModel;
 import forge.player.GamePlayerUtil;
 import forge.util.Localizer;
+import forge.util.URLValidator;
 import org.apache.commons.lang3.StringUtils;
 
-import java.net.URI;
+import static forge.util.URLValidator.parseURL;
 
 public class NetConnectUtil {
     private NetConnectUtil() { }
@@ -125,21 +126,17 @@ public class NetConnectUtil {
     public static ChatMessage join(final String url, final IOnlineLobby onlineLobby, final IOnlineChatInterface chatInterface) {
         final IGuiGame gui = GuiBase.getInterface().getNewGuiGame();
         String hostname;
-        int port = ForgeConstants.DEFAULT_SERVER_CONNECTION_PORT;
+        int port;
 
-        try {
+        URLValidator.HostPort hostPort = parseURL(url);
-            // Check if the URL already has a protocol
+        if(hostPort == null) {
-            String formattedUrl = url.matches("^[a-zA-Z][a-zA-Z0-9+.-]*://.*") ? url : "http://" + url;
+            return new ChatMessage(null, ForgeConstants.INVALID_HOST_COMMAND);
-            // Parse the URI
-            URI uri = new URI(formattedUrl);
-            hostname = uri.getHost();
-            if (uri.getPort() != -1) { // If a port is specified in the URL
-                port = uri.getPort();
-            }
-        } catch (Exception ex) {
-            hostname = url; // Fallback to original URL if parsing fails
         }
 
+        hostname = hostPort.host();
+        port = hostPort.port();
+        if(port == -1) port = ForgeConstants.DEFAULT_SERVER_CONNECTION_PORT;
+
 
         final FGameClient client = new FGameClient(FModel.getPreferences().getPref(FPref.PLAYER_NAME), "0", gui, hostname, port);
         onlineLobby.setClient(client);

forge-gui/src/main/java/forge/localinstance/properties/ForgeConstants.java

@@ -274,6 +274,7 @@ public final class ForgeConstants {
     public static final String CONQUEST_PREFS_FILE  = USER_PREFS_DIR + "conquest.preferences";
     public static final String ITEM_VIEW_PREFS_FILE = USER_PREFS_DIR + "item_view.preferences";
     public static final String CLOSE_CONN_COMMAND   = "<<_EM_ESOLC_<<";
+    public static final String INVALID_HOST_COMMAND   = "<<_TSOH_DILAVNI_<<";
 
     // data that has defaults in the program dir but overrides/additions in the user dir
     private static final String _DEFAULTS_DIR = RES_DIR + "defaults" + PATH_SEPARATOR;

forge-gui/src/main/java/forge/util/URLValidator.java

@@ -0,0 +1,52 @@
+package forge.util;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.regex.Pattern;
+
+public class URLValidator {
+
+    private static final Pattern DOMAIN_NAME_PATTERN = Pattern.compile("^(?!-)[A-Za-z0-9-]{1,63}(?<!-)(\\.[A-Za-z]{2,})+$");
+
+    public static HostPort parseIP(String ip) {
+        String[] parts = ip.split("\\.");
+        if (parts.length != 4) return null;
+        for (String part : parts) {
+            try {
+                int num = Integer.parseInt(part);
+                if (num < 0 || num > 255) return null;
+            } catch (NumberFormatException e) {
+                return null;
+            }
+        }
+        return new HostPort(ip, null); // No port for raw IP
+    }
+
+
+    public static HostPort parseURL(String url) {
+        try {
+            //prepend http:// if a protocol is missing so URI parsing does not fail
+            String formattedUrl = url.matches("^[a-zA-Z][a-zA-Z0-9+.-]*://.*") ? url : "http://" + url;
+            URI uri = new URI(formattedUrl);
+            String host = uri.getHost();
+            int port = uri.getPort(); // Returns -1 if port is not specified
+            if (host == null) return null;
+            HostPort hostPort;
+            if (parseIP(host) != null) {
+                hostPort = new HostPort(host, port == -1 ? null : port);
+            } else if (DOMAIN_NAME_PATTERN.matcher(host).matches()) {
+                hostPort = new HostPort(host, port == -1 ? null : port);
+            } else {
+                return null;
+            }
+            return hostPort;
+        } catch (URISyntaxException e) {
+            return null;
+        }
+    }
+
+    //This is fine, Records were introduced in Java 16, its essentially a DTO class with implicit getters and constructors
+    public record HostPort(String host, Integer port) {
+    }
+
+}