Updated pom version.

- custom font
- profile editor
- servers list
- custom data directory management.

client/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>ace-of-shades-2</artifactId>
         <groupId>nl.andrewl</groupId>
-        <version>1.3.0</version>
+        <version>1.5.0</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

client/src/main/java/nl/andrewl/aos2_client/Client.java

@@ -1,6 +1,7 @@
 package nl.andrewl.aos2_client;
 
 import nl.andrewl.aos2_client.config.ClientConfig;
+import nl.andrewl.aos2_client.config.ConnectConfig;
 import nl.andrewl.aos2_client.control.InputHandler;
 import nl.andrewl.aos2_client.model.Chat;
 import nl.andrewl.aos2_client.model.ClientPlayer;
@@ -26,7 +27,9 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentLinkedQueue;
 
 public class Client implements Runnable {
-	private final ClientConfig config;
+	public final ConnectConfig connectConfig;
+	public final ClientConfig config;
+
 	private final CommunicationHandler communicationHandler;
 	private final InputHandler inputHandler;
 	private final Camera camera;
@@ -42,8 +45,9 @@ public class Client implements Runnable {
 	private final Chat chat;
 	private final Queue<Runnable> mainThreadActions;
 
-	public Client(ClientConfig config) {
+	public Client(ClientConfig config, ConnectConfig connectConfig) {
 		this.config = config;
+		this.connectConfig = connectConfig;
 		this.camera = new Camera();
 		this.players = new ConcurrentHashMap<>();
 		this.teams = new ConcurrentHashMap<>();
@@ -156,6 +160,14 @@ public class Client implements Runnable {
 			});
 		} else if (msg instanceof PlayerLeaveMessage leaveMessage) {
 			runLater(() -> players.remove(leaveMessage.id()));
+		} else if (msg instanceof PlayerTeamUpdateMessage teamUpdateMessage) {
+			runLater(() -> {
+				OtherPlayer op = players.get(teamUpdateMessage.playerId());
+				Team team = teamUpdateMessage.teamId() == -1 ? null : teams.get(teamUpdateMessage.teamId());
+				if (op != null) {
+					op.setTeam(team);
+				}
+			});
 		} else if (msg instanceof SoundMessage soundMessage) {
 			if (soundManager != null) {
 				soundManager.play(
@@ -257,13 +269,22 @@ public class Client implements Runnable {
 	}
 
 	public static void main(String[] args) throws IOException {
+		if (args.length < 3) {
+			System.err.println("Missing required host, port, username args.");
+			System.exit(1);
+		}
+		String host = args[0].trim();
+		int port = Integer.parseInt(args[1]);
+		String username = args[2].trim();
+		ConnectConfig connectCfg = new ConnectConfig(host, port, username, false);
+
 		List<Path> configPaths = Config.getCommonConfigPaths();
 		configPaths.add(0, Path.of("client.yaml")); // Add this first so we create client.yaml if needed.
-		if (args.length > 0) {
-			configPaths.add(Path.of(args[0].trim()));
+		if (args.length > 3) {
+			configPaths.add(Path.of(args[3].trim()));
 		}
 		ClientConfig clientConfig = Config.loadConfig(ClientConfig.class, configPaths, new ClientConfig(), "default-config.yaml");
-		Client client = new Client(clientConfig);
+		Client client = new Client(clientConfig, connectCfg);
 		client.run();
 	}
 }

client/src/main/java/nl/andrewl/aos2_client/CommunicationHandler.java

@@ -8,7 +8,8 @@ import nl.andrewl.aos_core.model.Team;
 import nl.andrewl.aos_core.model.item.ItemStack;
 import nl.andrewl.aos_core.model.world.World;
 import nl.andrewl.aos_core.model.world.WorldIO;
-import nl.andrewl.aos_core.net.*;
+import nl.andrewl.aos_core.net.TcpReceiver;
+import nl.andrewl.aos_core.net.UdpReceiver;
 import nl.andrewl.aos_core.net.connect.ConnectAcceptMessage;
 import nl.andrewl.aos_core.net.connect.ConnectRejectMessage;
 import nl.andrewl.aos_core.net.connect.ConnectRequestMessage;
@@ -46,16 +47,14 @@ public class CommunicationHandler {
 		if (socket != null && !socket.isClosed()) {
 			socket.close();
 		}
-		InetAddress address = InetAddress.getByName(client.getConfig().serverHost);
-		int port = client.getConfig().serverPort;
-		String username = client.getConfig().username;
-		System.out.printf("Connecting to server at %s, port %d, with username \"%s\"...%n", address, port, username);
+		InetAddress address = InetAddress.getByName(client.connectConfig.host());
+		System.out.printf("Connecting to server at %s, port %d, with username \"%s\"...%n", address, client.connectConfig.port(), client.connectConfig.username());
 
-		socket = new Socket(address, port);
+		socket = new Socket(address, client.connectConfig.port());
 		socket.setSoTimeout(1000);
 		in = Net.getInputStream(socket.getInputStream());
 		out = Net.getOutputStream(socket.getOutputStream());
-		Net.write(new ConnectRequestMessage(username), out);
+		Net.write(new ConnectRequestMessage(client.connectConfig.username(), client.connectConfig.spectator()), out);
 		Message response = Net.read(in);
 		socket.setSoTimeout(0);
 		if (response instanceof ConnectRejectMessage rejectMessage) {
@@ -63,7 +62,7 @@ public class CommunicationHandler {
 		}
 		if (response instanceof ConnectAcceptMessage acceptMessage) {
 			this.clientId = acceptMessage.clientId();
-			client.setMyPlayer(new ClientPlayer(clientId, username));
+			client.setMyPlayer(new ClientPlayer(clientId, client.connectConfig.username()));
 			receiveInitialData();
 			establishDatagramConnection();
 			new Thread(new TcpReceiver(in, client::onMessageReceived).withShutdownHook(this::shutdown)).start();

client/src/main/java/nl/andrewl/aos2_client/config/ClientConfig.java

@@ -1,9 +1,6 @@
 package nl.andrewl.aos2_client.config;
 
 public class ClientConfig {
-	public String serverHost = "localhost";
-	public int serverPort = 25565;
-	public String username = "player";
 	public InputConfig input = new InputConfig();
 	public DisplayConfig display = new DisplayConfig();
 

client/src/main/java/nl/andrewl/aos2_client/config/ConnectConfig.java

@@ -0,0 +1,11 @@
+package nl.andrewl.aos2_client.config;
+
+/**
+ * The data that's needed by the client to initially establish a connection.
+ */
+public record ConnectConfig(
+		String host,
+		int port,
+		String username,
+		boolean spectator
+) {}

client/src/main/resources/default-config.yaml

@@ -1,8 +1,4 @@
 # Ace of Shades 2 Client Configuration
-# Set these properties to connect to a server.
-serverHost: localhost
-serverPort: 25565
-username: player
 
 # Settings for input.
 input:

core/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>ace-of-shades-2</artifactId>
         <groupId>nl.andrewl</groupId>
-        <version>1.3.0</version>
+        <version>1.5.0</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

core/src/main/java/nl/andrewl/aos_core/Net.java

@@ -26,29 +26,37 @@ public final class Net {
 
 	private static final Serializer serializer = new Serializer();
 	static {
-		serializer.registerType(1, ConnectRequestMessage.class);
-		serializer.registerType(2, ConnectAcceptMessage.class);
-		serializer.registerType(3, ConnectRejectMessage.class);
-		serializer.registerType(4, DatagramInit.class);
-		serializer.registerType(5, ChunkHashMessage.class);
-		serializer.registerType(6, ChunkDataMessage.class);
-		serializer.registerType(7, ChunkUpdateMessage.class);
-		serializer.registerType(8, ClientInputState.class);
-		serializer.registerType(9, ClientOrientationState.class);
-		serializer.registerType(10, PlayerUpdateMessage.class);
-		serializer.registerType(11, PlayerJoinMessage.class);
-		serializer.registerType(12, PlayerLeaveMessage.class);
+		int i = 1;
+		// Basic protocol messages.
+		serializer.registerType(i++, ConnectRequestMessage.class);
+		serializer.registerType(i++, ConnectAcceptMessage.class);
+		serializer.registerType(i++, ConnectRejectMessage.class);
+		serializer.registerType(i++, DatagramInit.class);
+
+		// World messages.
+		serializer.registerType(i++, ChunkHashMessage.class);
+		serializer.registerType(i++, ChunkDataMessage.class);
+		serializer.registerType(i++, ChunkUpdateMessage.class);
+		serializer.registerType(i++, ProjectileMessage.class);
+
+		// Player/client messages.
+		serializer.registerType(i++, ClientInputState.class);
+		serializer.registerType(i++, ClientOrientationState.class);
+		serializer.registerType(i++, ClientHealthMessage.class);
+		serializer.registerType(i++, PlayerUpdateMessage.class);
+		serializer.registerType(i++, PlayerJoinMessage.class);
+		serializer.registerType(i++, PlayerLeaveMessage.class);
+		serializer.registerType(i++, PlayerTeamUpdateMessage.class);
+		serializer.registerType(i++, BlockColorMessage.class);
+		serializer.registerType(i++, InventorySelectedStackMessage.class);
+		serializer.registerType(i++, ChatMessage.class);
+		serializer.registerType(i++, ChatWrittenMessage.class);
+		serializer.registerType(i++, ClientRecoilMessage.class);
 		// Separate serializers for client inventory messages.
-		serializer.registerTypeSerializer(13, new InventorySerializer());
-		serializer.registerTypeSerializer(14, new ItemStackSerializer());
-		serializer.registerType(15, InventorySelectedStackMessage.class);
-		serializer.registerType(16, SoundMessage.class);
-		serializer.registerType(17, ProjectileMessage.class);
-		serializer.registerType(18, ClientHealthMessage.class);
-		serializer.registerType(19, BlockColorMessage.class);
-		serializer.registerType(20, ChatMessage.class);
-		serializer.registerType(21, ChatWrittenMessage.class);
-		serializer.registerType(22, ClientRecoilMessage.class);
+		serializer.registerTypeSerializer(i++, new InventorySerializer());
+		serializer.registerTypeSerializer(i++, new ItemStackSerializer());
+
+		serializer.registerType(i++, SoundMessage.class);
 	}
 
 	public static ExtendedDataInputStream getInputStream(InputStream in) {

core/src/main/java/nl/andrewl/aos_core/net/client/PlayerTeamUpdateMessage.java

@@ -0,0 +1,13 @@
+package nl.andrewl.aos_core.net.client;
+
+import nl.andrewl.record_net.Message;
+
+/**
+ * A message that's sent by the server to announce that a player has changed to
+ * a specified team. Both the player and team should already be recognized by
+ * all clients; otherwise they can ignore this.
+ */
+public record PlayerTeamUpdateMessage(
+		int playerId,
+		int teamId
+) implements Message {}

core/src/main/java/nl/andrewl/aos_core/net/connect/ConnectRequestMessage.java

@@ -2,4 +2,10 @@ package nl.andrewl.aos_core.net.connect;
 
 import nl.andrewl.record_net.Message;
 
-public record ConnectRequestMessage(String username) implements Message {}
+/**
+ * The first message that a client sends via TCP to the server, to indicate
+ * that they'd like to join.
+ * @param username The player's chosen username.
+ * @param spectator Whether the player wants to be a spectator.
+ */
+public record ConnectRequestMessage(String username, boolean spectator) implements Message {}

launcher/package_linux.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+
+function join_by {
+   local d=${1-} f=${2-}
+   if shift 2; then
+     printf %s "$f" "${@/#/$d}"
+   fi
+}
+
+mvn clean package
+cd target
+module_jars=(lib/*)
+eligible_main_jars=("*.jar")
+main_jar=(${eligible_main_jars[0]})
+module_path=$(join_by ":" ${module_jars[@]})
+module_path="$main_jar:$module_path"
+echo $module_path
+jpackage \
+  --name "Ace of Shades Launcher" \
+  --app-version "1.0.0" \
+  --description "Launcher app for Ace of Shades, a voxel-based first-person shooter." \
+  --icon ../icon.ico \
+  --linux-shortcut \
+  --linux-deb-maintainer "andrewlalisofficial@gmail.com" \
+  --linux-menu-group "Game" \
+  --linux-app-category "Game" \
+  --module-path "$module_path" \
+  --module aos2_launcher/nl.andrewl.aos2_launcher.Launcher \
+  --add-modules jdk.crypto.cryptoki
+

launcher/package_windows.ps1

@@ -0,0 +1,42 @@
+# This script prepares and runs the jpackage command to generate a Windows AOS Client installer.
+
+$projectDir = $PSScriptRoot
+Push-Location $projectDir\target
+
+# Remove existing file if it exists.
+Write-Output "Removing existing exe file."
+Get-ChildItem *.exe | ForEach-Object { Remove-Item -Path $_.FullName -Force }
+Write-Output "Done."
+
+# Run the build
+Write-Output "Building the project."
+Push-Location $projectDir
+mvn clean package
+
+# Get list of dependency modules that maven copied into the lib directory.
+Push-Location $projectDir\target
+$modules = Get-ChildItem -Path lib -Name | ForEach-Object { "lib\$_" }
+# Add our own main module.
+$mainModuleJar = Get-ChildItem -Name -Include "aos2-launcher-*.jar" -Exclude "*-jar-with-dependencies.jar"
+$modules += $mainModuleJar
+Write-Output "Found modules: $modules"
+$modulePath = $modules -join ';'
+
+Write-Output "Running jpackage..."
+jpackage `
+ --type msi `
+ --name "Ace-of-Shades" `
+ --app-version "1.0.0" `
+ --description "Top-down 2D shooter game inspired by Ace of Spades." `
+ --icon ..\icon.ico `
+ --win-shortcut `
+ --win-dir-chooser `
+ --win-per-user-install `
+ --win-menu `
+ --win-shortcut `
+ --win-menu-group "Game" `
+ --module-path "$modulePath" `
+ --module aos2_launcher/nl.andrewl.aos2_launcher.Launcher `
+ --add-modules jdk.crypto.cryptoki
+
+Write-Output "Done!"

launcher/pom.xml

@@ -11,8 +11,9 @@
     <properties>
         <maven.compiler.source>18</maven.compiler.source>
         <maven.compiler.target>18</maven.compiler.target>
-        <javafx.version>18.0.1</javafx.version>
+        <javafx.version>18.0.2</javafx.version>
         <javafx.maven.plugin.version>0.0.8</javafx.maven.plugin.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
     <dependencies>
@@ -26,6 +27,12 @@
             <artifactId>javafx-fxml</artifactId>
             <version>${javafx.version}</version>
         </dependency>
+        <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.9.1</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -47,6 +54,46 @@
                     <target>17</target>
                 </configuration>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <version>3.3.0</version>
+                <configuration>
+                    <archive>
+                        <manifest>
+                            <mainClass>nl.andrewl.aos2_launcher.Launcher</mainClass>
+                        </manifest>
+                    </archive>
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <version>2.8</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/lib</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 

launcher/src/main/java/module-info.java

@@ -4,6 +4,10 @@ module aos2_launcher {
 	requires javafx.graphics;
 	requires javafx.fxml;
 
+	requires java.net.http;
+	requires com.google.gson;
+
 	exports nl.andrewl.aos2_launcher to javafx.graphics;
 	opens nl.andrewl.aos2_launcher to javafx.fxml;
+	opens nl.andrewl.aos2_launcher.view to javafx.fxml;
 }

launcher/src/main/java/nl/andrewl/aos2_launcher/EditProfileController.java

@@ -0,0 +1,4 @@
+package nl.andrewl.aos2_launcher;
+
+public class EditProfileController {
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/GameRunner.java

@@ -0,0 +1,70 @@
+package nl.andrewl.aos2_launcher;
+
+import javafx.application.Platform;
+import javafx.scene.control.Alert;
+import javafx.stage.Window;
+import nl.andrewl.aos2_launcher.model.Profile;
+import nl.andrewl.aos2_launcher.model.ProgressReporter;
+import nl.andrewl.aos2_launcher.model.Server;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+public class GameRunner {
+	public void run(Profile profile, Server server, ProgressReporter progressReporter, Window owner) {
+		SystemVersionValidator.getJreExecutablePath(progressReporter)
+				.whenCompleteAsync((jrePath, throwable) -> {
+					if (throwable != null) {
+						showPopup(
+								owner,
+								Alert.AlertType.ERROR,
+								"An error occurred while ensuring that you've got the latest Java runtime: " + throwable.getMessage()
+						);
+					} else {
+						VersionFetcher.INSTANCE.ensureVersionIsDownloaded(profile.getClientVersion(), progressReporter)
+								.whenCompleteAsync((clientJarPath, throwable2) -> {
+									progressReporter.disableProgress();
+									if (throwable2 != null) {
+										showPopup(
+												owner,
+												Alert.AlertType.ERROR,
+												"An error occurred while ensuring you've got the correct client version: " + throwable2.getMessage()
+										);
+									} else {
+										startGame(owner, profile, server, jrePath, clientJarPath);
+									}
+								});
+					}
+				});
+	}
+
+	private void startGame(Window owner, Profile profile, Server server, Path jrePath, Path clientJarPath) {
+		try {
+			Process p = new ProcessBuilder()
+					.command(
+							jrePath.toAbsolutePath().toString(),
+							"-jar", clientJarPath.toAbsolutePath().toString(),
+							server.getHost(),
+							Integer.toString(server.getPort()),
+							profile.getUsername()
+					)
+					.directory(profile.getDir().toFile())
+					.inheritIO()
+					.start();
+			p.wait();
+		} catch (IOException e) {
+			showPopup(owner, Alert.AlertType.ERROR, "An error occurred while starting the game: " + e.getMessage());
+		} catch (InterruptedException e) {
+			showPopup(owner, Alert.AlertType.ERROR, "The game was interrupted: " + e.getMessage());
+		}
+	}
+
+	private void showPopup(Window owner, Alert.AlertType type, String text) {
+		Platform.runLater(() -> {
+			Alert alert = new Alert(Alert.AlertType.ERROR);
+			alert.initOwner(owner);
+			alert.setContentText(text);
+			alert.show();
+		});
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/Launcher.java

@@ -7,22 +7,40 @@ import javafx.scene.Scene;
 import javafx.stage.Stage;
 
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 
 /**
  * The main starting point for the launcher app.
  */
 public class Launcher extends Application {
+	public static final Path BASE_DIR = Path.of(System.getProperty("user.home"), ".ace-of-shades");
+	public static final Path VERSIONS_DIR = BASE_DIR.resolve("versions");
+	public static final Path PROFILES_FILE = BASE_DIR.resolve("profiles.json");
+	public static final Path PROFILES_DIR =  BASE_DIR.resolve("profiles");
+	public static final Path JRE_PATH = BASE_DIR.resolve("jre");
+
 	@Override
 	public void start(Stage stage) throws IOException {
+		if (!Files.exists(BASE_DIR)) Files.createDirectory(BASE_DIR);
+		if (!Files.exists(VERSIONS_DIR)) Files.createDirectory(VERSIONS_DIR);
+		if (!Files.exists(PROFILES_DIR)) Files.createDirectory(PROFILES_DIR);
 		FXMLLoader loader = new FXMLLoader(Launcher.class.getResource("/main_view.fxml"));
 		Parent rootNode = loader.load();
 		Scene scene = new Scene(rootNode);
-		scene.getStylesheets().add(Launcher.class.getResource("/styles.css").toExternalForm());
+		addStylesheet(scene, "/font/fonts.css");
+		addStylesheet(scene, "/styles.css");
 		stage.setScene(scene);
-		stage.setTitle("Ace of Shades 2 - Launcher");
+		stage.setTitle("Ace of Shades - Launcher");
 		stage.show();
 	}
 
+	private void addStylesheet(Scene scene, String resource) throws IOException {
+		var url = Launcher.class.getResource(resource);
+		if (url == null) throw new IOException("Could not load resource at " + resource);
+		scene.getStylesheets().add(url.toExternalForm());
+	}
+
 	public static void main(String[] args) {
 		launch(args);
 	}

launcher/src/main/java/nl/andrewl/aos2_launcher/MainViewController.java

@@ -1,11 +1,140 @@
 package nl.andrewl.aos2_launcher;
 
+import javafx.application.Platform;
+import javafx.beans.binding.BooleanBinding;
+import javafx.collections.ListChangeListener;
 import javafx.fxml.FXML;
-import javafx.scene.layout.TilePane;
+import javafx.scene.control.*;
+import javafx.scene.layout.VBox;
+import javafx.stage.Window;
+import nl.andrewl.aos2_launcher.model.Profile;
+import nl.andrewl.aos2_launcher.model.ProfileSet;
+import nl.andrewl.aos2_launcher.model.ProgressReporter;
+import nl.andrewl.aos2_launcher.model.Server;
+import nl.andrewl.aos2_launcher.view.EditProfileDialog;
+import nl.andrewl.aos2_launcher.view.ElementList;
+import nl.andrewl.aos2_launcher.view.ProfileView;
+import nl.andrewl.aos2_launcher.view.ServerView;
+
+import java.util.ArrayList;
+
+public class MainViewController implements ProgressReporter {
+	@FXML public Button playButton;
+	@FXML public Button editProfileButton;
+	@FXML public Button removeProfileButton;
+	@FXML public VBox profilesVBox;
+	private ElementList<Profile, ProfileView> profilesList;
+	@FXML public VBox serversVBox;
+	private ElementList<Server, ServerView> serversList;
+
+	@FXML public VBox progressVBox;
+	@FXML public Label progressLabel;
+	@FXML public ProgressBar progressBar;
+	@FXML public TextField registryUrlField;
+
+	private final ProfileSet profileSet = new ProfileSet();
+
+	private ServersFetcher serversFetcher;
 
-public class MainViewController {
 	@FXML
-	public TilePane profilesTilePane;
+	public void initialize() {
+		profilesList = new ElementList<>(profilesVBox, ProfileView::new, ProfileView.class, ProfileView::getProfile);
+		profileSet.selectedProfileProperty().addListener((observable, oldValue, newValue) -> profileSet.save());
+		// A hack since we can't bind the profilesList's elements to the profileSet's.
+		profileSet.getProfiles().addListener((ListChangeListener<? super Profile>) c -> {
+			var selected = profileSet.getSelectedProfile();
+			profilesList.clear();
+			profilesList.addAll(profileSet.getProfiles());
+			profilesList.selectElement(selected);
+		});
+		profileSet.loadOrCreateStandardFile();
+		profilesList.selectElement(profileSet.getSelectedProfile());
+		profileSet.selectedProfileProperty().bind(profilesList.selectedElementProperty());
 
+		serversList = new ElementList<>(serversVBox, ServerView::new, ServerView.class, ServerView::getServer);
 
+		BooleanBinding playBind = profileSet.selectedProfileProperty().isNull().or(serversList.selectedElementProperty().isNull());
+		playButton.disableProperty().bind(playBind);
+		editProfileButton.disableProperty().bind(profileSet.selectedProfileProperty().isNull());
+		removeProfileButton.disableProperty().bind(profileSet.selectedProfileProperty().isNull());
+
+		progressVBox.managedProperty().bind(progressVBox.visibleProperty());
+		progressVBox.setVisible(false);
+
+		serversFetcher = new ServersFetcher(registryUrlField.textProperty());
+		Platform.runLater(this::refreshServers);
+	}
+
+	@FXML
+	public void refreshServers() {
+		Window owner = this.profilesVBox.getScene().getWindow();
+		serversFetcher.fetchServers(owner)
+				.exceptionally(throwable -> {
+					throwable.printStackTrace();
+					Platform.runLater(() -> {
+						Alert alert = new Alert(Alert.AlertType.ERROR);
+						alert.setHeaderText("Couldn't fetch servers.");
+						alert.setContentText("An error occurred, and the list of servers couldn't be fetched: " + throwable.getMessage() + ". Are you sure that you have the correct registry URL? Check the \"Servers\" tab.");
+						alert.initOwner(owner);
+						alert.show();
+					});
+					return new ArrayList<>();
+				})
+				.thenAccept(newServers -> Platform.runLater(() -> {
+					serversList.clear();
+					serversList.addAll(newServers);
+				}));
+	}
+
+	@FXML
+	public void addProfile() {
+		EditProfileDialog dialog = new EditProfileDialog(profilesVBox.getScene().getWindow());
+		dialog.showAndWait().ifPresent(profileSet::addNewProfile);
+	}
+
+	@FXML
+	public void editProfile() {
+		EditProfileDialog dialog = new EditProfileDialog(profilesVBox.getScene().getWindow(), profileSet.getSelectedProfile());
+		dialog.showAndWait();
+		profileSet.save();
+	}
+
+	@FXML
+	public void removeProfile() {
+		profileSet.removeSelectedProfile();
+	}
+
+	@FXML
+	public void play() {
+		new GameRunner().run(
+				profileSet.getSelectedProfile(),
+				serversList.getSelectedElement(),
+				this,
+				this.profilesVBox.getScene().getWindow()
+		);
+	}
+
+	@Override
+	public void enableProgress() {
+		Platform.runLater(() -> {
+			progressVBox.setVisible(true);
+			progressBar.setProgress(ProgressIndicator.INDETERMINATE_PROGRESS);
+			progressLabel.setText(null);
+		});
+	}
+
+	@Override
+	public void disableProgress() {
+		Platform.runLater(() -> progressVBox.setVisible(false));
+	}
+
+	@Override
+	public void setActionText(String text) {
+		Platform.runLater(() -> progressLabel.setText(text));
+	}
+
+	@Override
+	public void setProgress(double progress) {
+		Platform.runLater(() -> progressBar.setProgress(progress));
+	}
 }

launcher/src/main/java/nl/andrewl/aos2_launcher/ServersFetcher.java

@@ -0,0 +1,74 @@
+package nl.andrewl.aos2_launcher;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import javafx.application.Platform;
+import javafx.beans.property.SimpleStringProperty;
+import javafx.beans.property.StringProperty;
+import javafx.scene.control.Alert;
+import javafx.stage.Window;
+import nl.andrewl.aos2_launcher.model.Server;
+
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+
+class ServersFetcher {
+	private final HttpClient httpClient;
+	private final Gson gson;
+	private final StringProperty registryUrl;
+
+	public ServersFetcher(StringProperty registryUrlProperty) {
+		httpClient = HttpClient.newBuilder().build();
+		gson = new Gson();
+		this.registryUrl = new SimpleStringProperty("http://localhost:8080");
+		registryUrl.bind(registryUrlProperty);
+	}
+
+	public CompletableFuture<List<Server>> fetchServers(Window owner) {
+		if (registryUrl.get() == null || registryUrl.get().isBlank()) {
+			Platform.runLater(() -> {
+				Alert alert = new Alert(Alert.AlertType.WARNING);
+				alert.setContentText("Invalid or missing registry URL. Can't fetch the list of servers.");
+				alert.initOwner(owner);
+				alert.show();
+			});
+			return CompletableFuture.completedFuture(new ArrayList<>());
+		}
+		HttpRequest req = HttpRequest.newBuilder(URI.create(registryUrl.get() + "/servers"))
+				.GET()
+				.timeout(Duration.ofSeconds(3))
+				.header("Accept", "application/json")
+				.build();
+		return httpClient.sendAsync(req, HttpResponse.BodyHandlers.ofString())
+				.thenApplyAsync(resp -> {
+					if (resp.statusCode() == 200) {
+						JsonArray serversArray = gson.fromJson(resp.body(), JsonArray.class);
+						List<Server> servers = new ArrayList<>(serversArray.size());
+						for (JsonElement serverJson : serversArray) {
+							if (serverJson instanceof JsonObject obj) {
+								servers.add(new Server(
+										obj.get("host").getAsString(),
+										obj.get("port").getAsInt(),
+										obj.get("name").getAsString(),
+										obj.get("description").getAsString(),
+										obj.get("maxPlayers").getAsInt(),
+										obj.get("currentPlayers").getAsInt(),
+										obj.get("lastUpdatedAt").getAsLong()
+								));
+							}
+						}
+						return servers;
+					} else {
+						throw new RuntimeException("Invalid response: " + resp.statusCode());
+					}
+				});
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/SystemVersionValidator.java

@@ -0,0 +1,134 @@
+package nl.andrewl.aos2_launcher;
+
+import nl.andrewl.aos2_launcher.model.ProgressReporter;
+import nl.andrewl.aos2_launcher.util.FileUtils;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.time.Duration;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.BiPredicate;
+
+public class SystemVersionValidator {
+	private static final String os = System.getProperty("os.name").trim().toLowerCase();
+	private static final String arch = System.getProperty("os.arch").trim().toLowerCase();
+
+	private static final boolean OS_WINDOWS = os.contains("win");
+	private static final boolean OS_MAC = os.contains("mac");
+	private static final boolean OS_LINUX = os.contains("nix") || os.contains("nux") || os.contains("aix");
+
+	private static final boolean ARCH_X86 = arch.equals("x86");
+	private static final boolean ARCH_X86_64 = arch.equals("x86_64");
+	private static final boolean ARCH_AMD64 = arch.equals("amd64");
+	private static final boolean ARCH_AARCH64 = arch.equals("aarch64");
+	private static final boolean ARCH_ARM = arch.equals("arm");
+	private static final boolean ARCH_ARM32 = arch.equals("arm32");
+
+	private static final String JRE_DOWNLOAD_URL = "https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.4+8/";
+
+	public static String getPreferredVersionSuffix() {
+		if (OS_LINUX) {
+			if (ARCH_AARCH64) return "linux-aarch64";
+			if (ARCH_AMD64) return "linux-amd64";
+			if (ARCH_ARM) return "linux-arm";
+			if (ARCH_ARM32) return "linux-arm32";
+		} else if (OS_MAC) {
+			if (ARCH_AARCH64) return "macos-aarch64";
+			if (ARCH_X86_64) return "macos-x86_64";
+		} else if (OS_WINDOWS) {
+			if (ARCH_AARCH64) return "windows-aarch64";
+			if (ARCH_AMD64) return "windows-amd64";
+			if (ARCH_X86) return "windows-x86";
+		}
+		System.err.println("Couldn't determine the preferred OS/ARCH version. Defaulting to windows-amd64.");
+		return "windows-amd64";
+	}
+
+	public static CompletableFuture<Path> getJreExecutablePath(ProgressReporter progressReporter) {
+		Optional<Path> optionalExecutablePath = findJreExecutable();
+		return optionalExecutablePath.map(CompletableFuture::completedFuture)
+				.orElseGet(() -> downloadAppropriateJre(progressReporter));
+	}
+
+	public static CompletableFuture<Path> downloadAppropriateJre(ProgressReporter progressReporter) {
+		progressReporter.enableProgress();
+		progressReporter.setActionText("Downloading JRE...");
+		HttpClient httpClient = HttpClient.newBuilder().followRedirects(HttpClient.Redirect.NORMAL).build();
+		HttpRequest.Builder requestBuilder = HttpRequest.newBuilder().GET().timeout(Duration.ofMinutes(5));
+		String jreArchiveName = getPreferredJreName();
+		String url = JRE_DOWNLOAD_URL + jreArchiveName;
+		HttpRequest req = requestBuilder.uri(URI.create(url)).build();
+		return httpClient.sendAsync(req, HttpResponse.BodyHandlers.ofInputStream())
+				.thenApplyAsync(resp -> {
+					if (resp.statusCode() == 200) {
+						// Download sequentially, and update the progress.
+						try {
+							if (Files.exists(Launcher.JRE_PATH)) {
+								FileUtils.deleteRecursive(Launcher.JRE_PATH);
+							}
+							Files.createDirectory(Launcher.JRE_PATH);
+							Path jreArchiveFile = Launcher.JRE_PATH.resolve(jreArchiveName);
+							FileUtils.downloadWithProgress(jreArchiveFile, resp, progressReporter);
+							progressReporter.setProgress(-1); // Indefinite progress.
+							progressReporter.setActionText("Unpacking JRE...");
+							ProcessBuilder pb = new ProcessBuilder().inheritIO();
+							if (OS_LINUX || OS_MAC) {
+								pb.command("tar", "-xzf", jreArchiveFile.toAbsolutePath().toString(), "-C", Launcher.JRE_PATH.toAbsolutePath().toString());
+							} else if (OS_WINDOWS) {
+								pb.command("powershell", "-command", "\"Expand-Archive -Force '" + jreArchiveFile.toAbsolutePath() + "' '" + Launcher.JRE_PATH.toAbsolutePath() + "'\"");
+							}
+							Process process = pb.start();
+							int result = process.waitFor();
+							if (result != 0) throw new IOException("Archive extraction process exited with non-zero code: " + result);
+							Files.delete(jreArchiveFile);
+							progressReporter.setActionText("Looking for java executable...");
+							Optional<Path> optionalExecutablePath = findJreExecutable();
+							if (optionalExecutablePath.isEmpty()) throw new IOException("Couldn't find java executable.");
+							progressReporter.disableProgress();
+							return optionalExecutablePath.get();
+						} catch (IOException | InterruptedException e) {
+							throw new RuntimeException(e);
+						}
+					} else {
+						throw new RuntimeException("JRE download failed: " + resp.statusCode());
+					}
+				});
+	}
+
+	private static Optional<Path> findJreExecutable() {
+		if (!Files.exists(Launcher.JRE_PATH)) return Optional.empty();
+		BiPredicate<Path, BasicFileAttributes> pred = (path, basicFileAttributes) -> {
+			String filename = path.getFileName().toString();
+			return Files.isExecutable(path) && (filename.equals("java") || filename.equals("java.exe"));
+		};
+		try (var s = Files.find(Launcher.JRE_PATH, 3, pred)) {
+			return s.findFirst();
+		} catch (IOException e) {
+			e.printStackTrace();
+			return Optional.empty();
+		}
+	}
+
+	private static String getPreferredJreName() {
+		if (OS_LINUX) {
+			if (ARCH_AARCH64) return "OpenJDK17U-jre_aarch64_linux_hotspot_17.0.4_8.tar.gz";
+			if (ARCH_AMD64) return "OpenJDK17U-jre_x64_linux_hotspot_17.0.4_8.tar.gz";
+			if (ARCH_ARM || ARCH_ARM32) return "OpenJDK17U-jre_arm_linux_hotspot_17.0.4_8.tar.gz";
+		} else if (OS_MAC) {
+			if (ARCH_AARCH64) return "OpenJDK17U-jre_aarch64_mac_hotspot_17.0.4_8.tar.gz";
+			if (ARCH_X86_64) return "OpenJDK17U-jre_x64_mac_hotspot_17.0.4_8.tar.gz";
+		} else if (OS_WINDOWS) {
+			if (ARCH_AARCH64 || ARCH_AMD64) return "OpenJDK17U-jre_x64_windows_hotspot_17.0.4_8.zip";
+			if (ARCH_X86) return "OpenJDK17U-jre_x86-32_windows_hotspot_17.0.4_8.zip";
+		}
+		System.err.println("Couldn't determine the preferred JRE version. Defaulting to x64_windows.");
+		return "OpenJDK17U-jre_x64_windows_hotspot_17.0.4_8.zip";
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/VersionFetcher.java

@@ -0,0 +1,177 @@
+package nl.andrewl.aos2_launcher;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import nl.andrewl.aos2_launcher.model.ClientVersionRelease;
+import nl.andrewl.aos2_launcher.model.ProgressReporter;
+import nl.andrewl.aos2_launcher.util.FileUtils;
+
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Duration;
+import java.time.LocalDateTime;
+import java.time.OffsetDateTime;
+import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+import java.util.*;
+import java.util.concurrent.CompletableFuture;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class VersionFetcher {
+	private static final String BASE_GITHUB_URL = "https://api.github.com/repos/andrewlalis/ace-of-shades-2";
+
+	public static final VersionFetcher INSTANCE = new VersionFetcher();
+
+	private final List<ClientVersionRelease> availableReleases;
+
+	private final HttpClient httpClient = HttpClient.newBuilder().followRedirects(HttpClient.Redirect.NORMAL).build();
+	private boolean loaded = false;
+	private CompletableFuture<List<ClientVersionRelease>> activeReleaseFetchFuture;
+
+	public VersionFetcher() {
+		this.availableReleases = new ArrayList<>();
+	}
+
+	public CompletableFuture<ClientVersionRelease> getRelease(String versionTag) {
+		return getAvailableReleases().thenApply(releases -> releases.stream()
+				.filter(r -> r.tag().equals(versionTag))
+				.findFirst().orElse(null));
+	}
+
+	public CompletableFuture<List<ClientVersionRelease>> getAvailableReleases() {
+		if (loaded) {
+			return CompletableFuture.completedFuture(Collections.unmodifiableList(availableReleases));
+		}
+		return fetchReleasesFromGitHub();
+	}
+
+	private CompletableFuture<List<ClientVersionRelease>> fetchReleasesFromGitHub() {
+		if (activeReleaseFetchFuture != null) return activeReleaseFetchFuture;
+		HttpRequest req = HttpRequest.newBuilder(URI.create(BASE_GITHUB_URL + "/releases"))
+				.timeout(Duration.ofSeconds(3))
+				.GET()
+				.build();
+		activeReleaseFetchFuture = httpClient.sendAsync(req, HttpResponse.BodyHandlers.ofInputStream())
+				.thenApplyAsync(resp -> {
+					if (resp.statusCode() == 200) {
+						JsonArray releasesArray = new Gson().fromJson(new InputStreamReader(resp.body()), JsonArray.class);
+						availableReleases.clear();
+						for (var element : releasesArray) {
+							if (element.isJsonObject()) {
+								JsonObject obj = element.getAsJsonObject();
+								String tag = obj.get("tag_name").getAsString();
+								String apiUrl = obj.get("url").getAsString();
+								String assetsUrl = obj.get("assets_url").getAsString();
+								OffsetDateTime publishedAt = OffsetDateTime.parse(obj.get("published_at").getAsString(), DateTimeFormatter.ISO_OFFSET_DATE_TIME);
+								LocalDateTime localPublishedAt = publishedAt.atZoneSameInstant(ZoneId.systemDefault()).toLocalDateTime();
+								availableReleases.add(new ClientVersionRelease(tag, apiUrl, assetsUrl, localPublishedAt));
+							}
+						}
+						availableReleases.sort(Comparator.comparing(ClientVersionRelease::publishedAt).reversed());
+						loaded = true;
+						return availableReleases;
+					} else {
+						throw new RuntimeException("Error while requesting releases.");
+					}
+				});
+		return activeReleaseFetchFuture;
+	}
+
+	public List<String> getDownloadedVersions() {
+		try (var s = Files.list(Launcher.VERSIONS_DIR)) {
+			return s.filter(this::isVersionFile)
+					.map(this::extractVersion)
+					.toList();
+		} catch (IOException e) {
+			e.printStackTrace();
+			return Collections.emptyList();
+		}
+	}
+
+	public CompletableFuture<Path> ensureVersionIsDownloaded(String versionTag, ProgressReporter progressReporter) {
+		try (var s = Files.list(Launcher.VERSIONS_DIR)) {
+			Optional<Path> optionalFile = s.filter(f -> isVersionFile(f) && versionTag.equals(extractVersion(f)))
+					.findFirst();
+			if (optionalFile.isPresent()) return CompletableFuture.completedFuture(optionalFile.get());
+		} catch (IOException e) {
+			return CompletableFuture.failedFuture(e);
+		}
+		progressReporter.enableProgress();
+		progressReporter.setActionText("Downloading client " + versionTag + "...");
+		var future = getRelease(versionTag)
+				.thenComposeAsync(release -> downloadVersion(release, progressReporter));
+		future.thenRun(progressReporter::disableProgress);
+		return future;
+	}
+
+	private CompletableFuture<Path> downloadVersion(ClientVersionRelease release, ProgressReporter progressReporter) {
+		System.out.println("Downloading version " + release.tag());
+		HttpRequest req = HttpRequest.newBuilder(URI.create(release.assetsUrl()))
+				.GET().timeout(Duration.ofSeconds(3)).build();
+		CompletableFuture<JsonObject> downloadUrlFuture = httpClient.sendAsync(req, HttpResponse.BodyHandlers.ofInputStream())
+				.thenApplyAsync(resp -> {
+					if (resp.statusCode() == 200) {
+						JsonArray assetsArray = new Gson().fromJson(new InputStreamReader(resp.body()), JsonArray.class);
+						String preferredVersionSuffix = SystemVersionValidator.getPreferredVersionSuffix();
+						String regex = "aos2-client-\\d+\\.\\d+\\.\\d+-" + preferredVersionSuffix + "\\.jar";
+						for (var asset : assetsArray) {
+							JsonObject assetObj = asset.getAsJsonObject();
+							String name = assetObj.get("name").getAsString();
+							if (name.matches(regex)) {
+								return assetObj;
+							}
+						}
+						throw new RuntimeException("Couldn't find a matching release asset for this system.");
+					} else {
+						throw new RuntimeException("Error while requesting release assets from GitHub: " + resp.statusCode());
+					}
+				});
+		return downloadUrlFuture.thenComposeAsync(asset -> {
+			String url = asset.get("browser_download_url").getAsString();
+			String fileName = asset.get("name").getAsString();
+			HttpRequest downloadRequest = HttpRequest.newBuilder(URI.create(url))
+					.GET().timeout(Duration.ofMinutes(5)).build();
+			Path file = Launcher.VERSIONS_DIR.resolve(fileName);
+			return httpClient.sendAsync(downloadRequest, HttpResponse.BodyHandlers.ofInputStream())
+					.thenApplyAsync(resp -> {
+						if (resp.statusCode() == 200) {
+							// Download sequentially, and update the progress.
+							try {
+								FileUtils.downloadWithProgress(file, resp, progressReporter);
+							} catch (IOException e) {
+								throw new RuntimeException(e);
+							}
+							return file;
+						} else {
+							throw new RuntimeException("Error while downloading release asset from GitHub: " + resp.statusCode());
+						}
+					});
+		});
+	}
+
+	private boolean isVersionDownloaded(String versionTag) {
+		return getDownloadedVersions().contains(versionTag);
+	}
+
+	private boolean isVersionFile(Path p) {
+		return Files.isRegularFile(p) && p.getFileName().toString()
+				.matches("aos2-client-\\d+\\.\\d+\\.\\d+-.+\\.jar");
+	}
+
+	private String extractVersion(Path file) {
+		Pattern pattern = Pattern.compile("\\d+\\.\\d+\\.\\d+");
+		Matcher matcher = pattern.matcher(file.getFileName().toString());
+		if (matcher.find()) {
+			return "v" + matcher.group();
+		}
+		throw new IllegalArgumentException("File doesn't contain a valid version pattern.");
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/model/ClientVersionRelease.java

@@ -0,0 +1,11 @@
+package nl.andrewl.aos2_launcher.model;
+
+import java.time.LocalDateTime;
+import java.time.ZonedDateTime;
+
+public record ClientVersionRelease (
+		String tag,
+		String apiUrl,
+		String assetsUrl,
+		LocalDateTime publishedAt
+) {}

launcher/src/main/java/nl/andrewl/aos2_launcher/model/Profile.java

@@ -0,0 +1,84 @@
+package nl.andrewl.aos2_launcher.model;
+
+import javafx.beans.property.SimpleStringProperty;
+import javafx.beans.property.StringProperty;
+import nl.andrewl.aos2_launcher.Launcher;
+
+import java.nio.file.Path;
+import java.util.UUID;
+
+public class Profile {
+	private final UUID id;
+	private final StringProperty name;
+	private final StringProperty username;
+	private final StringProperty clientVersion;
+	private final StringProperty jvmArgs;
+
+	public Profile() {
+		this(UUID.randomUUID(), "", "Player", null, null);
+	}
+
+	public Profile(UUID id, String name, String username, String clientVersion, String jvmArgs) {
+		this.id = id;
+		this.name = new SimpleStringProperty(name);
+		this.username = new SimpleStringProperty(username);
+		this.clientVersion = new SimpleStringProperty(clientVersion);
+		this.jvmArgs = new SimpleStringProperty(jvmArgs);
+	}
+
+	public UUID getId() {
+		return id;
+	}
+
+	public String getName() {
+		return name.get();
+	}
+
+	public StringProperty nameProperty() {
+		return name;
+	}
+
+	public String getUsername() {
+		return username.get();
+	}
+
+	public StringProperty usernameProperty() {
+		return username;
+	}
+
+	public String getClientVersion() {
+		return clientVersion.get();
+	}
+
+	public StringProperty clientVersionProperty() {
+		return clientVersion;
+	}
+
+	public String getJvmArgs() {
+		return jvmArgs.get();
+	}
+
+	public StringProperty jvmArgsProperty() {
+		return jvmArgs;
+	}
+
+	public void setName(String name) {
+		this.name.set(name);
+	}
+
+	public void setUsername(String username) {
+		this.username.set(username);
+	}
+
+	public void setClientVersion(String clientVersion) {
+		this.clientVersion.set(clientVersion);
+	}
+
+	public void setJvmArgs(String jvmArgs) {
+		this.jvmArgs.set(jvmArgs);
+	}
+
+	public Path getDir() {
+		return Launcher.PROFILES_DIR.resolve(id.toString());
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/model/ProfileSet.java

@@ -0,0 +1,155 @@
+package nl.andrewl.aos2_launcher.model;
+
+import com.google.gson.*;
+import javafx.beans.property.ObjectProperty;
+import javafx.beans.property.SimpleObjectProperty;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import nl.andrewl.aos2_launcher.Launcher;
+import nl.andrewl.aos2_launcher.util.FileUtils;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.UUID;
+
+/**
+ * Model for managing the set of profiles in the app.
+ */
+public class ProfileSet {
+	private final ObservableList<Profile> profiles;
+	private final ObjectProperty<Profile> selectedProfile;
+	private Path lastFileUsed = null;
+
+	public ProfileSet() {
+		this.profiles = FXCollections.observableArrayList();
+		this.selectedProfile = new SimpleObjectProperty<>(null);
+	}
+
+	public ProfileSet(Path file) throws IOException {
+		this();
+		load(file);
+	}
+
+	public void addNewProfile(Profile profile) {
+		profiles.add(profile);
+		save();
+		try {
+			if (!Files.exists(profile.getDir())) {
+				Files.createDirectory(profile.getDir());
+			}
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	public void removeProfile(Profile profile) {
+		if (profile == null) return;
+		boolean removed = profiles.remove(profile);
+		if (removed) {
+			try {
+				if (Files.exists(profile.getDir())) {
+					FileUtils.deleteRecursive(profile.getDir());
+				}
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+			save();
+		}
+	}
+
+	public void removeSelectedProfile() {
+		removeProfile(getSelectedProfile());
+	}
+
+	public void load(Path file) throws IOException {
+		try (var reader = Files.newBufferedReader(file)) {
+			JsonObject data = new Gson().fromJson(reader, JsonObject.class);
+			profiles.clear();
+			JsonElement selectedProfileIdElement = data.get("selectedProfileId");
+			UUID selectedProfileId = (selectedProfileIdElement == null || selectedProfileIdElement.isJsonNull())
+					? null
+					: UUID.fromString(selectedProfileIdElement.getAsString());
+			JsonArray profilesArray = data.getAsJsonArray("profiles");
+			for (JsonElement element : profilesArray) {
+				JsonObject profileObj = element.getAsJsonObject();
+				UUID id = UUID.fromString(profileObj.get("id").getAsString());
+				String name = profileObj.get("name").getAsString();
+				String clientVersion = profileObj.get("clientVersion").getAsString();
+				String username = profileObj.get("username").getAsString();
+				JsonElement jvmArgsElement = profileObj.get("jvmArgs");
+				String jvmArgs = null;
+				if (jvmArgsElement != null && jvmArgsElement.isJsonPrimitive() && jvmArgsElement.getAsJsonPrimitive().isString()) {
+					jvmArgs = jvmArgsElement.getAsString();
+				}
+				Profile profile = new Profile(id, name, username, clientVersion, jvmArgs);
+				profiles.add(profile);
+				if (selectedProfileId != null && selectedProfileId.equals(profile.getId())) {
+					selectedProfile.set(profile);
+				}
+			}
+			lastFileUsed = file;
+		}
+	}
+
+	public void loadOrCreateStandardFile() {
+		if (!Files.exists(Launcher.PROFILES_FILE)) {
+			try {
+				save(Launcher.PROFILES_FILE);
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+		} else {
+			try {
+				load(Launcher.PROFILES_FILE);
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+		}
+
+	}
+
+	public void save(Path file) throws IOException {
+		Gson gson = new GsonBuilder().setPrettyPrinting().create();
+		JsonObject data = new JsonObject();
+		String selectedProfileId = selectedProfile.getValue() == null ? null : selectedProfile.getValue().getId().toString();
+		data.addProperty("selectedProfileId", selectedProfileId);
+		JsonArray profilesArray = new JsonArray(profiles.size());
+		for (Profile profile : profiles) {
+			JsonObject obj = new JsonObject();
+			obj.addProperty("id", profile.getId().toString());
+			obj.addProperty("name", profile.getName());
+			obj.addProperty("username", profile.getUsername());
+			obj.addProperty("clientVersion", profile.getClientVersion());
+			obj.addProperty("jvmArgs", profile.getJvmArgs());
+			profilesArray.add(obj);
+		}
+		data.add("profiles", profilesArray);
+		try (var writer = Files.newBufferedWriter(file)) {
+			gson.toJson(data, writer);
+		}
+		lastFileUsed = file;
+	}
+
+	public void save() {
+		if (lastFileUsed != null) {
+			try {
+				save(lastFileUsed);
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+		}
+	}
+
+	public ObservableList<Profile> getProfiles() {
+		return profiles;
+	}
+
+	public Profile getSelectedProfile() {
+		return selectedProfile.get();
+	}
+
+	public ObjectProperty<Profile> selectedProfileProperty() {
+		return selectedProfile;
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/model/ProgressReporter.java

@@ -0,0 +1,8 @@
+package nl.andrewl.aos2_launcher.model;
+
+public interface ProgressReporter {
+	void enableProgress();
+	void disableProgress();
+	void setActionText(String text);
+	void setProgress(double progress);
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/model/Server.java

@@ -0,0 +1,84 @@
+package nl.andrewl.aos2_launcher.model;
+
+import javafx.beans.property.*;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+
+public class Server {
+	private final StringProperty host;
+	private final IntegerProperty port;
+	private final StringProperty name;
+	private final StringProperty description;
+	private final IntegerProperty maxPlayers;
+	private final IntegerProperty currentPlayers;
+	private final ObjectProperty<LocalDateTime> lastUpdatedAt;
+
+	public Server(String host, int port, String name, String description, int maxPlayers, int currentPlayers, long lastUpdatedAt) {
+		this.host = new SimpleStringProperty(host);
+		this.port = new SimpleIntegerProperty(port);
+		this.name = new SimpleStringProperty(name);
+		this.description = new SimpleStringProperty(description);
+		this.maxPlayers = new SimpleIntegerProperty(maxPlayers);
+		this.currentPlayers = new SimpleIntegerProperty(currentPlayers);
+		LocalDateTime ts = Instant.ofEpochMilli(lastUpdatedAt).atZone(ZoneId.systemDefault()).toLocalDateTime();
+		this.lastUpdatedAt = new SimpleObjectProperty<>(ts);
+	}
+
+	public String getHost() {
+		return host.get();
+	}
+
+	public StringProperty hostProperty() {
+		return host;
+	}
+
+	public int getPort() {
+		return port.get();
+	}
+
+	public IntegerProperty portProperty() {
+		return port;
+	}
+
+	public String getName() {
+		return name.get();
+	}
+
+	public StringProperty nameProperty() {
+		return name;
+	}
+
+	public String getDescription() {
+		return description.get();
+	}
+
+	public StringProperty descriptionProperty() {
+		return description;
+	}
+
+	public int getMaxPlayers() {
+		return maxPlayers.get();
+	}
+
+	public IntegerProperty maxPlayersProperty() {
+		return maxPlayers;
+	}
+
+	public int getCurrentPlayers() {
+		return currentPlayers.get();
+	}
+
+	public IntegerProperty currentPlayersProperty() {
+		return currentPlayers;
+	}
+
+	public LocalDateTime getLastUpdatedAt() {
+		return lastUpdatedAt.get();
+	}
+
+	public Property<LocalDateTime> lastUpdatedAtProperty() {
+		return lastUpdatedAt;
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/util/FileUtils.java

@@ -0,0 +1,74 @@
+package nl.andrewl.aos2_launcher.util;
+
+import nl.andrewl.aos2_launcher.model.ProgressReporter;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.http.HttpResponse;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.text.CharacterIterator;
+import java.text.StringCharacterIterator;
+
+public class FileUtils {
+	public static String humanReadableByteCountSI(long bytes) {
+		if (-1000 < bytes && bytes < 1000) {
+			return bytes + " B";
+		}
+		CharacterIterator ci = new StringCharacterIterator("kMGTPE");
+		while (bytes <= -999_950 || bytes >= 999_950) {
+			bytes /= 1000;
+			ci.next();
+		}
+		return String.format("%.1f %cB", bytes / 1000.0, ci.current());
+	}
+
+	public static String humanReadableByteCountBin(long bytes) {
+		long absB = bytes == Long.MIN_VALUE ? Long.MAX_VALUE : Math.abs(bytes);
+		if (absB < 1024) {
+			return bytes + " B";
+		}
+		long value = absB;
+		CharacterIterator ci = new StringCharacterIterator("KMGTPE");
+		for (int i = 40; i >= 0 && absB > 0xfffccccccccccccL >> i; i -= 10) {
+			value >>= 10;
+			ci.next();
+		}
+		value *= Long.signum(bytes);
+		return String.format("%.1f %ciB", value / 1024.0, ci.current());
+	}
+
+	public static void deleteRecursive(Path p) throws IOException {
+		Files.walkFileTree(p, new SimpleFileVisitor<>() {
+			@Override
+			public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
+				Files.delete(file);
+				return FileVisitResult.CONTINUE;
+			}
+
+			@Override
+			public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
+				Files.delete(dir);
+				return FileVisitResult.CONTINUE;
+			}
+		});
+	}
+
+	public static void downloadWithProgress(Path outputFile, HttpResponse<InputStream> resp, ProgressReporter reporter) throws IOException {
+		reporter.setProgress(0);
+		long size = resp.headers().firstValueAsLong("Content-Length").orElse(1);
+		try (var out = Files.newOutputStream(outputFile); var in = resp.body()) {
+			byte[] buffer = new byte[8192];
+			long bytesRead = 0;
+			while (bytesRead < size) {
+				int readCount = in.read(buffer);
+				out.write(buffer, 0, readCount);
+				bytesRead += readCount;
+				reporter.setProgress((double) bytesRead / size);
+			}
+		}
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/view/BindingUtil.java

@@ -0,0 +1,90 @@
+package nl.andrewl.aos2_launcher.view;
+
+import javafx.beans.WeakListener;
+import javafx.collections.ListChangeListener;
+import javafx.collections.ObservableList;
+
+import java.lang.ref.WeakReference;
+import java.util.List;
+import java.util.function.Function;
+
+import static java.util.stream.Collectors.toList;
+
+public class BindingUtil {
+	public static <E, F> void mapContent(ObservableList<F> mapped, ObservableList<? extends E> source,
+										 Function<? super E, ? extends F> mapper) {
+		map(mapped, source, mapper);
+	}
+
+	private static <E, F> Object map(ObservableList<F> mapped, ObservableList<? extends E> source,
+									 Function<? super E, ? extends F> mapper) {
+		final ListContentMapping<E, F> contentMapping = new ListContentMapping<>(mapped, mapper);
+		mapped.setAll(source.stream().map(mapper).collect(toList()));
+		source.removeListener(contentMapping);
+		source.addListener(contentMapping);
+		return contentMapping;
+	}
+
+	private static class ListContentMapping<E, F> implements ListChangeListener<E>, WeakListener {
+		private final WeakReference<List<F>> mappedRef;
+		private final Function<? super E, ? extends F> mapper;
+
+		public ListContentMapping(List<F> mapped, Function<? super E, ? extends F> mapper) {
+			this.mappedRef = new WeakReference<>(mapped);
+			this.mapper = mapper;
+		}
+
+		@Override
+		public void onChanged(Change<? extends E> change) {
+			final List<F> mapped = mappedRef.get();
+			if (mapped == null) {
+				change.getList().removeListener(this);
+			} else {
+				while (change.next()) {
+					if (change.wasPermutated()) {
+						mapped.subList(change.getFrom(), change.getTo()).clear();
+						mapped.addAll(change.getFrom(), change.getList().subList(change.getFrom(), change.getTo())
+								.stream().map(mapper).toList());
+					} else {
+						if (change.wasRemoved()) {
+							mapped.subList(change.getFrom(), change.getFrom() + change.getRemovedSize()).clear();
+						}
+						if (change.wasAdded()) {
+							mapped.addAll(change.getFrom(), change.getAddedSubList()
+									.stream().map(mapper).toList());
+						}
+					}
+				}
+			}
+		}
+
+		@Override
+		public boolean wasGarbageCollected() {
+			return mappedRef.get() == null;
+		}
+
+		@Override
+		public int hashCode() {
+			final List<F> list = mappedRef.get();
+			return (list == null) ? 0 : list.hashCode();
+		}
+
+		@Override
+		public boolean equals(Object obj) {
+			if (this == obj) {
+				return true;
+			}
+
+			final List<F> mapped1 = mappedRef.get();
+			if (mapped1 == null) {
+				return false;
+			}
+
+			if (obj instanceof final ListContentMapping<?, ?> other) {
+				final List<?> mapped2 = other.mappedRef.get();
+				return mapped1 == mapped2;
+			}
+			return false;
+		}
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/view/EditProfileDialog.java

@@ -0,0 +1,96 @@
+package nl.andrewl.aos2_launcher.view;
+
+import javafx.application.Platform;
+import javafx.beans.binding.BooleanBinding;
+import javafx.beans.property.ObjectProperty;
+import javafx.beans.property.SimpleObjectProperty;
+import javafx.collections.FXCollections;
+import javafx.fxml.FXML;
+import javafx.fxml.FXMLLoader;
+import javafx.scene.Parent;
+import javafx.scene.control.*;
+import javafx.stage.Modality;
+import javafx.stage.Window;
+import nl.andrewl.aos2_launcher.VersionFetcher;
+import nl.andrewl.aos2_launcher.model.ClientVersionRelease;
+import nl.andrewl.aos2_launcher.model.Profile;
+
+import java.io.IOException;
+import java.util.Objects;
+
+public class EditProfileDialog extends Dialog<Profile> {
+	@FXML public TextField nameField;
+	@FXML public TextField usernameField;
+	@FXML public ChoiceBox<String> clientVersionChoiceBox;
+	@FXML public TextArea jvmArgsTextArea;
+
+	private final ObjectProperty<Profile> profile;
+
+	public EditProfileDialog(Window owner, Profile profile) {
+		this.profile = new SimpleObjectProperty<>(profile);
+		try {
+			FXMLLoader loader = new FXMLLoader(EditProfileDialog.class.getResource("/dialog/edit_profile.fxml"));
+			loader.setController(this);
+			Parent parent = loader.load();
+			initOwner(owner);
+			initModality(Modality.APPLICATION_MODAL);
+			setResizable(true);
+			setTitle("Edit Profile");
+
+			BooleanBinding formInvalid = nameField.textProperty().isEmpty()
+					.or(clientVersionChoiceBox.valueProperty().isNull())
+					.or(usernameField.textProperty().isEmpty());
+			nameField.setText(profile.getName());
+			usernameField.setText(profile.getUsername());
+			VersionFetcher.INSTANCE.getAvailableReleases()
+					.whenComplete((releases, throwable) -> Platform.runLater(() -> {
+						if (throwable == null) {
+							clientVersionChoiceBox.setItems(FXCollections.observableArrayList(releases.stream().map(ClientVersionRelease::tag).toList()));
+							// If the profile doesn't have a set version, use the latest release.
+							if (profile.getClientVersion() == null || profile.getClientVersion().isBlank()) {
+								String lastRelease = releases.size() == 0 ? null : releases.get(0).tag();
+								if (lastRelease != null) {
+									clientVersionChoiceBox.setValue(lastRelease);
+								}
+							} else {
+								clientVersionChoiceBox.setValue(profile.getClientVersion());
+							}
+						} else {
+							throwable.printStackTrace();
+							Alert alert = new Alert(Alert.AlertType.ERROR);
+							alert.initOwner(this.getOwner());
+							alert.setContentText("An error occurred while fetching the latest game releases: " + throwable.getMessage());
+							alert.show();
+						}
+			}));
+			jvmArgsTextArea.setText(profile.getJvmArgs());
+
+			DialogPane pane = new DialogPane();
+			pane.setContent(parent);
+			ButtonType okButton = new ButtonType("Ok", ButtonBar.ButtonData.OK_DONE);
+			ButtonType cancelButton = new ButtonType("Cancel", ButtonBar.ButtonData.CANCEL_CLOSE);
+			pane.getButtonTypes().add(okButton);
+			pane.getButtonTypes().add(cancelButton);
+			pane.lookupButton(okButton).disableProperty().bind(formInvalid);
+			setDialogPane(pane);
+			setResultConverter(buttonType -> {
+				if (!Objects.equals(ButtonBar.ButtonData.OK_DONE, buttonType.getButtonData())) {
+					return null;
+				}
+				var prof = this.profile.getValue();
+				prof.setName(nameField.getText().trim());
+				prof.setUsername(usernameField.getText().trim());
+				prof.setClientVersion(clientVersionChoiceBox.getValue());
+				prof.setJvmArgs(jvmArgsTextArea.getText());
+				return this.profile.getValue();
+			});
+			setOnShowing(event -> Platform.runLater(() -> nameField.requestFocus()));
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	public EditProfileDialog(Window owner) {
+		this(owner, new Profile());
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/view/ElementList.java

@@ -0,0 +1,111 @@
+package nl.andrewl.aos2_launcher.view;
+
+import javafx.beans.property.ObjectProperty;
+import javafx.beans.property.SimpleObjectProperty;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.css.PseudoClass;
+import javafx.scene.Node;
+import javafx.scene.input.MouseEvent;
+import javafx.scene.layout.Pane;
+
+import java.util.Collection;
+import java.util.function.Function;
+
+public class ElementList<T, V extends Node> {
+	private final Pane container;
+
+	private final ObjectProperty<T> selectedElement = new SimpleObjectProperty<>(null);
+	private final ObservableList<T> elements = FXCollections.observableArrayList();
+	private final Class<V> elementViewType;
+	private final Function<V, T> viewElementMapper;
+
+	public ElementList(
+			Pane container,
+			Function<T, V> elementViewMapper,
+			Class<V> elementViewType,
+			Function<V, T> viewElementMapper
+	) {
+		this.container = container;
+		this.elementViewType = elementViewType;
+		this.viewElementMapper = viewElementMapper;
+		BindingUtil.mapContent(container.getChildren(), elements, element -> {
+			V view = elementViewMapper.apply(element);
+			view.getStyleClass().add("element-list-item");
+			return view;
+		});
+		container.addEventHandler(MouseEvent.MOUSE_CLICKED, this::handleMouseClick);
+	}
+
+	@SuppressWarnings("unchecked")
+	private void handleMouseClick(MouseEvent event) {
+		Node target = (Node) event.getTarget();
+		while (target != null) {
+			if (target.getClass().equals(elementViewType)) {
+				V elementView = (V) target;
+				T targetElement = viewElementMapper.apply(elementView);
+				if (event.isControlDown()) {
+					if (selectedElement.get() == null) {
+						selectElement(targetElement);
+					} else {
+						selectElement(null);
+					}
+				} else {
+					selectElement(targetElement);
+				}
+				return; // Exit since we found a valid target.
+			}
+			target = target.getParent();
+		}
+		selectElement(null);
+	}
+
+	public void selectElement(T element) {
+		if (element != null && !elements.contains(element)) return;
+		selectedElement.set(element);
+		updateSelectedPseudoClass();
+	}
+
+	@SuppressWarnings("unchecked")
+	private void updateSelectedPseudoClass() {
+		PseudoClass selectedClass = PseudoClass.getPseudoClass("selected");
+		for (var node : container.getChildren()) {
+			if (!node.getClass().equals(elementViewType)) continue;
+			V view = (V) node;
+			T thisElement = viewElementMapper.apply(view);
+			view.pseudoClassStateChanged(selectedClass, thisElement.equals(selectedElement.get()));
+		}
+	}
+
+	public T getSelectedElement() {
+		return selectedElement.get();
+	}
+
+	public ObjectProperty<T> selectedElementProperty() {
+		return selectedElement;
+	}
+
+	public ObservableList<T> getElements() {
+		return elements;
+	}
+
+	public void clear() {
+		elements.clear();
+		selectElement(null);
+	}
+
+	public void add(T element) {
+		elements.add(element);
+	}
+
+	public void addAll(Collection<T> newElements) {
+		elements.addAll(newElements);
+	}
+
+	public void remove(T element) {
+		elements.remove(element);
+		if (element != null && element.equals(selectedElement.get())) {
+			selectElement(null);
+		}
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/view/ProfileView.java

@@ -0,0 +1,38 @@
+package nl.andrewl.aos2_launcher.view;
+
+import javafx.fxml.FXML;
+import javafx.fxml.FXMLLoader;
+import javafx.scene.Node;
+import javafx.scene.control.Label;
+import javafx.scene.layout.Pane;
+import nl.andrewl.aos2_launcher.model.Profile;
+
+import java.io.IOException;
+
+public class ProfileView extends Pane {
+	private final Profile profile;
+
+	@FXML public Label nameLabel;
+	@FXML public Label clientVersionLabel;
+	@FXML public Label usernameLabel;
+
+	public ProfileView(Profile profile) {
+		this.profile = profile;
+
+		try {
+			FXMLLoader loader = new FXMLLoader(ProfileView.class.getResource("/profile_view.fxml"));
+			loader.setController(this);
+			Node node = loader.load();
+			getChildren().add(node);
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+		nameLabel.textProperty().bind(profile.nameProperty());
+		clientVersionLabel.textProperty().bind(profile.clientVersionProperty());
+		usernameLabel.textProperty().bind(profile.usernameProperty());
+	}
+
+	public Profile getProfile() {
+		return this.profile;
+	}
+}

launcher/src/main/java/nl/andrewl/aos2_launcher/view/ServerView.java

@@ -0,0 +1,33 @@
+package nl.andrewl.aos2_launcher.view;
+
+import javafx.scene.control.Label;
+import javafx.scene.layout.VBox;
+import nl.andrewl.aos2_launcher.model.Server;
+
+public class ServerView extends VBox {
+	private final Server server;
+
+	public ServerView(Server server) {
+		this.server = server;
+		var hostLabel = new Label();
+		hostLabel.textProperty().bind(server.hostProperty());
+		var portLabel = new Label();
+		portLabel.setText(Integer.toString(server.getPort()));
+		server.portProperty().addListener((observableValue, x1, x2) -> {
+			portLabel.setText(x2.toString());
+		});
+		var nameLabel = new Label();
+		nameLabel.textProperty().bind(server.nameProperty());
+		var descriptionLabel = new Label();
+		descriptionLabel.textProperty().bind(server.descriptionProperty());
+		var playersLabel = new Label();
+
+		var nodes = getChildren();
+		nodes.addAll(hostLabel, portLabel, nameLabel, descriptionLabel);
+		getStyleClass().add("list-item");
+	}
+
+	public Server getServer() {
+		return server;
+	}
+}

launcher/src/main/resources/dialog/edit_profile.fxml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.geometry.*?>
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+
+<AnchorPane minHeight="-Infinity" minWidth="-Infinity" prefHeight="300.0" prefWidth="400.0" xmlns="http://javafx.com/javafx/16" xmlns:fx="http://javafx.com/fxml/1">
+   <VBox maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" spacing="10.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
+      <padding>
+         <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
+      </padding>
+      <AnchorPane VBox.vgrow="NEVER">
+         <Label text="Profile Name" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.topAnchor="0.0" />
+         <TextField fx:id="nameField" promptText="Enter a name for the profile..." AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="150.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
+      </AnchorPane>
+      <AnchorPane VBox.vgrow="NEVER">
+         <Label text="Username" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.topAnchor="0.0" />
+         <TextField fx:id="usernameField" promptText="Enter a username..." AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="150.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
+      </AnchorPane>
+      <AnchorPane VBox.vgrow="NEVER">
+         <Label text="Client Version" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.topAnchor="0.0" />
+         <ChoiceBox fx:id="clientVersionChoiceBox" prefWidth="150.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="150.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
+      </AnchorPane>
+      <AnchorPane>
+         <Label text="JVM Arguments" wrapText="true" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.topAnchor="0.0"/>
+         <TextArea fx:id="jvmArgsTextArea" prefHeight="100.0" prefWidth="200.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="150.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0"/>
+      </AnchorPane>
+   </VBox>
+</AnchorPane>

launcher/src/main/resources/font/fonts.css

@@ -0,0 +1,27 @@
+@font-face {
+    src: url('JetBrainsMono-Regular.ttf');
+}
+
+@font-face {
+    src: url('JetBrainsMono-Bold.ttf');
+}
+
+@font-face {
+    src: url('JetBrainsMono-Light.ttf');
+}
+
+@font-face {
+    src: url('JetBrainsMono-Italic.ttf');
+}
+
+@font-face {
+    src: url('JetBrainsMono-BoldItalic.ttf');
+}
+
+@font-face {
+    src: url('JetBrainsMono-LightItalic.ttf');
+}
+
+.root {
+    -fx-font-family: "JetBrains Mono";
+}

launcher/src/main/resources/main_view.fxml

@@ -1,24 +1,50 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
+<?import javafx.geometry.*?>
 <?import javafx.scene.control.*?>
 <?import javafx.scene.layout.*?>
+<?import javafx.scene.text.*?>
 
-<VBox xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/16"
-      maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0"
-      fx:controller="nl.andrewl.aos2_launcher.MainViewController"
->
-    <MenuBar>
-        <Menu mnemonicParsing="false" text="File">
-            <MenuItem mnemonicParsing="false" text="Exit"/>
-        </Menu>
-        <Menu mnemonicParsing="false" text="Profiles">
-            <MenuItem mnemonicParsing="false" text="New Profile"/>
-        </Menu>
-        <Menu mnemonicParsing="false" text="Help">
-            <MenuItem mnemonicParsing="false" text="About"/>
-        </Menu>
-    </MenuBar>
-    <ScrollPane VBox.vgrow="ALWAYS">
-        <TilePane fx:id="profilesTilePane"/>
-    </ScrollPane>
+<VBox minHeight="300.0" minWidth="300.0" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/17.0.2-ea" xmlns:fx="http://javafx.com/fxml/1" fx:controller="nl.andrewl.aos2_launcher.MainViewController">
+    <TabPane tabClosingPolicy="UNAVAILABLE" VBox.vgrow="ALWAYS">
+        <Tab text="Profiles">
+            <VBox>
+                <HBox alignment="CENTER" styleClass="button-bar" VBox.vgrow="NEVER">
+                    <Button onAction="#addProfile" text="Add Profile" />
+                    <Button fx:id="editProfileButton" onAction="#editProfile" text="Edit Profile" />
+                    <Button fx:id="removeProfileButton" onAction="#removeProfile" text="Remove Profile" />
+                </HBox>
+                <ScrollPane fitToWidth="true" VBox.vgrow="ALWAYS">
+                    <VBox fx:id="profilesVBox" styleClass="banner-list" />
+                </ScrollPane>
+            </VBox>
+        </Tab>
+        <Tab text="Servers">
+            <VBox>
+                <HBox alignment="CENTER" styleClass="button-bar" VBox.vgrow="NEVER">
+                    <Button onAction="#refreshServers" text="Refresh" />
+               <TextField fx:id="registryUrlField" prefWidth="300.0" promptText="Registry URL" text="http://localhost:8080" style="-fx-font-size: 10px;" />
+                </HBox>
+                <ScrollPane fitToWidth="true" VBox.vgrow="ALWAYS">
+                    <VBox fx:id="serversVBox" styleClass="banner-list" />
+                </ScrollPane>
+            </VBox>
+        </Tab>
+    </TabPane>
+    <HBox alignment="CENTER" styleClass="button-bar" VBox.vgrow="NEVER">
+        <Button fx:id="playButton" mnemonicParsing="false" onAction="#play" text="Play" />
+    </HBox>
+    <VBox fx:id="progressVBox" VBox.vgrow="NEVER">
+        <AnchorPane VBox.vgrow="NEVER">
+            <padding>
+                <Insets bottom="5.0" left="5.0" right="5.0" top="5.0" />
+            </padding>
+            <Label fx:id="progressLabel" text="Work in progress..." AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.topAnchor="0.0">
+                <font>
+                    <Font size="10.0" />
+                </font>
+            </Label>
+            <ProgressBar fx:id="progressBar" prefWidth="200.0" progress="0.0" AnchorPane.bottomAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
+        </AnchorPane>
+    </VBox>
 </VBox>

launcher/src/main/resources/profile_view.fxml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.geometry.Insets?>
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+<BorderPane prefWidth="300.0" xmlns="http://javafx.com/javafx/16" xmlns:fx="http://javafx.com/fxml/1">
+   <padding><Insets top="5" bottom="5" left="5" right="5"/></padding>
+   <top>
+      <Label fx:id="nameLabel" text="Profile Name" BorderPane.alignment="CENTER_LEFT" style="-fx-font-size: 16px; -fx-font-weight: bold;">
+         <BorderPane.margin>
+            <Insets bottom="5.0" />
+         </BorderPane.margin>
+      </Label>
+   </top>
+   <center>
+      <VBox BorderPane.alignment="CENTER">
+         <AnchorPane VBox.vgrow="NEVER">
+            <Label text="Client Version" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0"
+                   AnchorPane.topAnchor="0.0"/>
+            <Label fx:id="clientVersionLabel" text="v1.0.0" textAlignment="RIGHT" AnchorPane.bottomAnchor="0.0"
+                   AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" style="-fx-font-weight: bold;"/>
+         </AnchorPane>
+         <AnchorPane VBox.vgrow="NEVER">
+            <Label text="Username" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0"
+                   AnchorPane.topAnchor="0.0"/>
+            <Label fx:id="usernameLabel" text="Player" textAlignment="RIGHT" AnchorPane.bottomAnchor="0.0"
+                   AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" style="-fx-font-weight: bold;"/>
+         </AnchorPane>
+      </VBox>
+   </center>
+</BorderPane>

launcher/src/main/resources/styles.css

@@ -0,0 +1,22 @@
+.test{
+    -fx-background-color: blue;
+}
+
+.button-bar {
+    -fx-padding: 5 0 5 0;
+    -fx-spacing: 5;
+    -fx-font-weight: bold;
+    -fx-font-size: 16px;
+}
+
+.banner-list {
+    -fx-spacing: 5;
+}
+
+.element-list-item:selected {
+    -fx-background-color: #e3e3e3;
+}
+
+#playButton {
+    -fx-border-radius: 0;
+}

pom.xml

@@ -7,7 +7,7 @@
     <groupId>nl.andrewl</groupId>
     <artifactId>ace-of-shades-2</artifactId>
     <packaging>pom</packaging>
-    <version>1.3.0</version>
+    <version>1.5.0</version>
     <modules>
         <module>core</module>
         <module>server</module>

registry/.gitignore

@@ -0,0 +1,33 @@
+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/

registry/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.6/apache-maven-3.8.6-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar

registry/README.md

@@ -0,0 +1,34 @@
+# Ace of Shades Server Registry
+The registry is a REST API that keeps track of any servers that have recently announced their status to it. Servers can periodically send a simple JSON object with metadata about the server (name, description, players, etc.) so that players can more easily search for a server to play on.
+
+### Fetching
+Client/launcher applications that want to get a list of servers from the registry should send a GET request to the API's `/servers` endpoint.
+
+The following array of servers is returned from GET requests to the API's `/servers` endpoint:
+```json
+[
+    {
+        "host": "0:0:0:0:0:0:0:1",
+        "port": 1234,
+        "name": "Andrew's Server",
+        "description": "A good server.",
+        "maxPlayers": 32,
+        "currentPlayers": 2,
+        "lastUpdatedAt": 1659710488855
+    }
+]
+```
+
+### Posting
+The following payload should be sent by servers to the API's `/servers` endpoint via POST:
+```json
+{
+    "port": 1234,
+    "token": "abc123",
+    "name": "Andrew's Server",
+    "description": "A good server.",
+    "maxPlayers": 32,
+    "currentPlayers": 2
+}
+```
+Note that this should only be done at most once per minute. Any more frequent, and you'll receive 429 Too-Many-Requests responses, and continued spam may permanently block your server.

registry/build-native.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+# Put your GRAALVM location here.
+export GRAALVM_HOME=/home/andrew/Downloads/graalvm-ce-java17-22.2.0
+mvn -Pnative -DskipTests clean package

registry/mvnw

@@ -0,0 +1,316 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /usr/local/etc/mavenrc ] ; then
+    . /usr/local/etc/mavenrc
+  fi
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`\\unset -f command; \\command -v java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath" || rm -f "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath" || rm -f "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  $MAVEN_DEBUG_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" \
+  "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

registry/mvnw.cmd

@@ -0,0 +1,188 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%USERPROFILE%\mavenrc_pre.bat" call "%USERPROFILE%\mavenrc_pre.bat" %*
+if exist "%USERPROFILE%\mavenrc_pre.cmd" call "%USERPROFILE%\mavenrc_pre.cmd" %*
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar"
+
+FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% ^
+  %JVM_CONFIG_MAVEN_PROPS% ^
+  %MAVEN_OPTS% ^
+  %MAVEN_DEBUG_OPTS% ^
+  -classpath %WRAPPER_JAR% ^
+  "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" ^
+  %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%"=="" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%USERPROFILE%\mavenrc_post.bat" call "%USERPROFILE%\mavenrc_post.bat"
+if exist "%USERPROFILE%\mavenrc_post.cmd" call "%USERPROFILE%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%"=="on" pause
+
+if "%MAVEN_TERMINATE_CMD%"=="on" exit %ERROR_CODE%
+
+cmd /C exit /B %ERROR_CODE%

registry/pom.xml

@@ -0,0 +1,150 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.7.2</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>nl.andrewl</groupId>
+	<artifactId>aos2-registry-api</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>aos2-registry-api</name>
+	<description>Registry API for Ace of Shades 2 servers.</description>
+	<properties>
+		<java.version>17</java.version>
+		<repackage.classifier/>
+		<spring-native.version>0.12.1</spring-native.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-webflux</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.experimental</groupId>
+			<artifactId>spring-native</artifactId>
+			<version>${spring-native.version}</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-devtools</artifactId>
+			<scope>runtime</scope>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>io.projectreactor</groupId>
+			<artifactId>reactor-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<configuration>
+					<classifier>${repackage.classifier}</classifier>
+					<image>
+						<builder>paketobuildpacks/builder:tiny</builder>
+						<env>
+							<BP_NATIVE_IMAGE>true</BP_NATIVE_IMAGE>
+						</env>
+					</image>
+				</configuration>
+			</plugin>
+			<plugin>
+				<groupId>org.springframework.experimental</groupId>
+				<artifactId>spring-aot-maven-plugin</artifactId>
+				<version>${spring-native.version}</version>
+				<executions>
+					<execution>
+						<id>test-generate</id>
+						<goals>
+							<goal>test-generate</goal>
+						</goals>
+					</execution>
+					<execution>
+						<id>generate</id>
+						<goals>
+							<goal>generate</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+	<repositories>
+		<repository>
+			<id>spring-releases</id>
+			<name>Spring Releases</name>
+			<url>https://repo.spring.io/release</url>
+			<snapshots>
+				<enabled>false</enabled>
+			</snapshots>
+		</repository>
+	</repositories>
+	<pluginRepositories>
+		<pluginRepository>
+			<id>spring-releases</id>
+			<name>Spring Releases</name>
+			<url>https://repo.spring.io/release</url>
+			<snapshots>
+				<enabled>false</enabled>
+			</snapshots>
+		</pluginRepository>
+	</pluginRepositories>
+
+	<profiles>
+		<profile>
+			<id>native</id>
+			<properties>
+				<repackage.classifier>exec</repackage.classifier>
+				<native-buildtools.version>0.9.13</native-buildtools.version>
+			</properties>
+			<dependencies>
+				<dependency>
+					<groupId>org.junit.platform</groupId>
+					<artifactId>junit-platform-launcher</artifactId>
+					<scope>test</scope>
+				</dependency>
+			</dependencies>
+			<build>
+				<plugins>
+					<plugin>
+						<groupId>org.graalvm.buildtools</groupId>
+						<artifactId>native-maven-plugin</artifactId>
+						<version>${native-buildtools.version}</version>
+						<extensions>true</extensions>
+						<executions>
+							<execution>
+								<id>test-native</id>
+								<phase>test</phase>
+								<goals>
+									<goal>test</goal>
+								</goals>
+							</execution>
+							<execution>
+								<id>build-native</id>
+								<phase>package</phase>
+								<goals>
+									<goal>build</goal>
+								</goals>
+							</execution>
+						</executions>
+					</plugin>
+				</plugins>
+			</build>
+		</profile>
+	</profiles>
+
+</project>

registry/src/main/java/nl/andrewl/aos2registryapi/Aos2RegistryApiApplication.java

@@ -0,0 +1,15 @@
+package nl.andrewl.aos2registryapi;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
+@SpringBootApplication
+@EnableScheduling
+public class Aos2RegistryApiApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(Aos2RegistryApiApplication.class, args);
+	}
+
+}

registry/src/main/java/nl/andrewl/aos2registryapi/ServerInfoValidator.java

@@ -0,0 +1,33 @@
+package nl.andrewl.aos2registryapi;
+
+import nl.andrewl.aos2registryapi.dto.ServerInfoPayload;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+public class ServerInfoValidator {
+
+	public boolean validateName(String name) {
+		return name != null && !name.isBlank() && name.length() <= 64;
+	}
+
+	public boolean validateDescription(String description) {
+		return description == null ||
+				(!description.isBlank() && description.length() <= 256);
+	}
+
+	public boolean validatePlayerCounts(int max, int current) {
+		return max > 0 && current >= 0 && current <= max && max < 1000;
+	}
+
+	public Optional<List<String>> validatePayload(ServerInfoPayload payload) {
+		List<String> messages = new ArrayList<>(3);
+		if (payload.port() < 0 || payload.port() > 65535) messages.add("Invalid port.");
+		if (!validateName(payload.name())) messages.add("Invalid name.");
+		if (!validateDescription(payload.description())) messages.add("Invalid description.");
+		if (!validatePlayerCounts(payload.maxPlayers(), payload.currentPlayers())) messages.add("Invalid player counts.");
+		if (messages.size() > 0) return Optional.of(messages);
+		return Optional.empty();
+	}
+}

registry/src/main/java/nl/andrewl/aos2registryapi/ServerRegistry.java

@@ -0,0 +1,89 @@
+package nl.andrewl.aos2registryapi;
+
+import nl.andrewl.aos2registryapi.dto.ServerInfoPayload;
+import nl.andrewl.aos2registryapi.dto.ServerInfoResponse;
+import nl.andrewl.aos2registryapi.model.ServerIdentifier;
+import nl.andrewl.aos2registryapi.model.ServerInfo;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+import org.springframework.web.server.ResponseStatusException;
+import reactor.core.publisher.Flux;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Comparator;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
+
+@Component
+public class ServerRegistry {
+	private static final Logger log = LoggerFactory.getLogger(ServerRegistry.class);
+
+	public static final Duration SERVER_TIMEOUT = Duration.ofMinutes(3);
+	public static final Duration SERVER_MIN_UPDATE = Duration.ofSeconds(5);
+
+	private final Map<ServerIdentifier, ServerInfo> servers = new ConcurrentHashMap<>();
+	private final ServerInfoValidator infoValidator = new ServerInfoValidator();
+
+	public Flux<ServerInfoResponse> getServers() {
+		Stream<ServerInfoResponse> stream = servers.entrySet().stream()
+				.sorted(Comparator.comparing(entry -> entry.getValue().getLastUpdatedAt()))
+				.map(entry -> new ServerInfoResponse(
+						entry.getKey().host(),
+						entry.getKey().port(),
+						entry.getValue().getName(),
+						entry.getValue().getDescription(),
+						entry.getValue().getMaxPlayers(),
+						entry.getValue().getCurrentPlayers(),
+						entry.getValue().getLastUpdatedAt().toEpochMilli()
+				));
+		return Flux.fromStream(stream);
+	}
+
+	public void acceptInfo(ServerIdentifier ident, ServerInfoPayload payload) {
+		var result = infoValidator.validatePayload(payload);
+		if (result.isPresent()) {
+			throw new ResponseStatusException(HttpStatus.BAD_REQUEST, String.join(" ", result.get()));
+		}
+		ServerInfo info = servers.get(ident);
+		if (info != null) {
+			Instant now = Instant.now();
+			// Check if this update was sent too fast.
+			if (Duration.between(info.getLastUpdatedAt(), now).compareTo(SERVER_MIN_UPDATE) < 0) {
+				throw new ResponseStatusException(HttpStatus.TOO_MANY_REQUESTS, "Server update rate limit exceeded.");
+			}
+			// Update existing server.
+			info.setName(payload.name());
+			info.setDescription(payload.description());
+			info.setMaxPlayers(payload.maxPlayers());
+			info.setCurrentPlayers(payload.currentPlayers());
+			info.setLastUpdatedAt(now);
+		} else {
+			// Save new server.
+			servers.put(ident, new ServerInfo(payload.name(), payload.description(), payload.maxPlayers(), payload.currentPlayers()));
+		}
+	}
+
+	@Scheduled(fixedRate = 1, timeUnit = TimeUnit.MINUTES, initialDelay = 1)
+	public void purgeOldServers() {
+		Queue<ServerIdentifier> removalQueue = new LinkedList<>();
+		final Instant cutoff = Instant.now().minus(SERVER_TIMEOUT);
+		for (var entry : servers.entrySet()) {
+			var ident = entry.getKey();
+			var server = entry.getValue();
+			if (server.getLastUpdatedAt().isBefore(cutoff)) {
+				removalQueue.add(ident);
+			}
+		}
+		while (!removalQueue.isEmpty()) {
+			servers.remove(removalQueue.remove());
+		}
+	}
+}

registry/src/main/java/nl/andrewl/aos2registryapi/api/ErrorAdvice.java

@@ -0,0 +1,21 @@
+package nl.andrewl.aos2registryapi.api;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@RestControllerAdvice
+public class ErrorAdvice {
+
+	@ExceptionHandler(ResponseStatusException.class)
+	public ResponseEntity<?> handleRSE(ResponseStatusException e) {
+		Map<String, Object> data = new HashMap<>();
+		data.put("code", e.getRawStatusCode());
+		data.put("message", e.getReason());
+		return ResponseEntity.status(e.getStatus()).body(data);
+	}
+}

registry/src/main/java/nl/andrewl/aos2registryapi/api/ServersController.java

@@ -0,0 +1,36 @@
+package nl.andrewl.aos2registryapi.api;
+
+import nl.andrewl.aos2registryapi.ServerRegistry;
+import nl.andrewl.aos2registryapi.dto.ServerInfoPayload;
+import nl.andrewl.aos2registryapi.dto.ServerInfoResponse;
+import nl.andrewl.aos2registryapi.model.ServerIdentifier;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.web.bind.annotation.*;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+@RestController
+@RequestMapping(path = "/servers")
+public class ServersController {
+	private final ServerRegistry serverRegistry;
+
+	public ServersController(ServerRegistry serverRegistry) {
+		this.serverRegistry = serverRegistry;
+	}
+
+	@GetMapping
+	public Flux<ServerInfoResponse> getServers() {
+		return serverRegistry.getServers();
+	}
+
+	@PostMapping
+	public Mono<ResponseEntity<Object>> updateServer(ServerHttpRequest req, @RequestBody Mono<ServerInfoPayload> payloadMono) {
+		String host = req.getRemoteAddress().getAddress().getHostAddress();
+		return payloadMono.mapNotNull(payload -> {
+			ServerIdentifier ident = new ServerIdentifier(host, payload.port());
+			serverRegistry.acceptInfo(ident, payload);
+			return ResponseEntity.ok(null);
+		});
+	}
+}

registry/src/main/java/nl/andrewl/aos2registryapi/dto/ServerInfoPayload.java

@@ -0,0 +1,9 @@
+package nl.andrewl.aos2registryapi.dto;
+
+public record ServerInfoPayload (
+		int port,
+		String name,
+		String description,
+		int maxPlayers,
+		int currentPlayers
+) {}

registry/src/main/java/nl/andrewl/aos2registryapi/dto/ServerInfoResponse.java

@@ -0,0 +1,11 @@
+package nl.andrewl.aos2registryapi.dto;
+
+public record ServerInfoResponse (
+		String host,
+		int port,
+		String name,
+		String description,
+		int maxPlayers,
+		int currentPlayers,
+		long lastUpdatedAt
+) {}

registry/src/main/java/nl/andrewl/aos2registryapi/model/ServerIdentifier.java

@@ -0,0 +1,3 @@
+package nl.andrewl.aos2registryapi.model;
+
+public record ServerIdentifier(String host, int port) {}

registry/src/main/java/nl/andrewl/aos2registryapi/model/ServerInfo.java

@@ -0,0 +1,59 @@
+package nl.andrewl.aos2registryapi.model;
+
+import java.time.Instant;
+
+public class ServerInfo {
+	private String name;
+	private String description;
+	private int maxPlayers;
+	private int currentPlayers;
+	private Instant lastUpdatedAt;
+
+	public ServerInfo(String name, String description, int maxPlayers, int currentPlayers) {
+		this.name = name;
+		this.description = description;
+		this.maxPlayers = maxPlayers;
+		this.currentPlayers = currentPlayers;
+		this.lastUpdatedAt = Instant.now();
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public String getDescription() {
+		return description;
+	}
+
+	public int getMaxPlayers() {
+		return maxPlayers;
+	}
+
+	public int getCurrentPlayers() {
+		return currentPlayers;
+	}
+
+	public Instant getLastUpdatedAt() {
+		return lastUpdatedAt;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public void setDescription(String description) {
+		this.description = description;
+	}
+
+	public void setMaxPlayers(int maxPlayers) {
+		this.maxPlayers = maxPlayers;
+	}
+
+	public void setCurrentPlayers(int currentPlayers) {
+		this.currentPlayers = currentPlayers;
+	}
+
+	public void setLastUpdatedAt(Instant lastUpdatedAt) {
+		this.lastUpdatedAt = lastUpdatedAt;
+	}
+}

registry/src/main/resources/application.properties

@@ -0,0 +1 @@
+spring.main.web-application-type=REACTIVE

registry/src/test/java/nl/andrewl/aos2registryapi/Aos2RegistryApiApplicationTests.java

@@ -0,0 +1,13 @@
+package nl.andrewl.aos2registryapi;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class Aos2RegistryApiApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}

server/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>ace-of-shades-2</artifactId>
         <groupId>nl.andrewl</groupId>
-        <version>1.3.0</version>
+        <version>1.5.0</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
@@ -33,6 +33,12 @@
             <artifactId>jansi</artifactId>
             <version>2.4.0</version>
         </dependency>
+        <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.9.1</version>
+        </dependency>
     </dependencies>
 
     <build>

server/src/main/java/nl/andrewl/aos2_server/ClientCommunicationHandler.java

@@ -107,12 +107,16 @@ public class ClientCommunicationHandler {
 						socket.close();
 						return;
 					}
+					if (server.getPlayerManager().getPlayers().size() >= server.getConfig().maxPlayers) {
+						Net.write(new ConnectRejectMessage("Server is full."), out);
+						socket.close();
+						return;
+					}
 
 					// Try to set the TCP timeout back to 0 now that we've got the correct request.
 					socket.setSoTimeout(0);
 					this.clientAddress = socket.getInetAddress();
-					connectionEstablished = true;
-					this.player = server.getPlayerManager().register(this, connectMsg.username());
+					this.player = server.getPlayerManager().register(this, connectMsg.username(), connectMsg.spectator());
 					Net.write(new ConnectAcceptMessage(player.getId()), out);
 					sendInitialData();
 					sendTcpMessage(ChatMessage.privateMessage("Welcome to the server, " + player.getUsername() + "."));
@@ -123,6 +127,7 @@ public class ClientCommunicationHandler {
 					TcpReceiver tcpReceiver = new TcpReceiver(in, this::handleTcpMessage)
 							.withShutdownHook(() -> server.getPlayerManager().deregister(this.player));
 					new Thread(tcpReceiver).start();
+					connectionEstablished = true;
 				}
 			} catch (SocketTimeoutException e) {
 				// Ignore this one, since this will happen if the client doesn't send data properly.
@@ -231,7 +236,7 @@ public class ClientCommunicationHandler {
 			out.writeFloat(player.getOrientation().y());
 
 			out.writeBoolean(player.isCrouching());
-			out.writeInt(player.getInventory().getSelectedItemStack().getType().getId());
+			out.writeInt(player.getInventory().getSelectedItemStack() == null ? -1 : player.getInventory().getSelectedItemStack().getType().getId());
 			out.writeByte(player.getInventory().getSelectedBlockValue());
 			out.writeInt(player.getMode().ordinal());
 		}

server/src/main/java/nl/andrewl/aos2_server/PlayerManager.java

@@ -29,22 +29,30 @@ public class PlayerManager {
 		this.server = server;
 	}
 
-	public synchronized ServerPlayer register(ClientCommunicationHandler handler, String username) {
-		ServerPlayer player = new ServerPlayer(nextClientId++, username);
+	public synchronized ServerPlayer register(ClientCommunicationHandler handler, String username, boolean spectator) {
+		PlayerMode mode = spectator ? PlayerMode.SPECTATOR : PlayerMode.NORMAL;
+		Team team = mode != PlayerMode.NORMAL ? null : findBestTeamForNewPlayer();
+		ServerPlayer player = new ServerPlayer(nextClientId++, username, team, mode);
+		if (player.getMode() == PlayerMode.NORMAL || player.getMode() == PlayerMode.CREATIVE) {
+			var inv = player.getInventory();
+			inv.getItemStacks().add(new GunItemStack(ItemTypes.RIFLE));
+			inv.getItemStacks().add(new GunItemStack(ItemTypes.AK_47));
+			inv.getItemStacks().add(new GunItemStack(ItemTypes.WINCHESTER));
+			inv.getItemStacks().add(new BlockItemStack(ItemTypes.BLOCK, 50, (byte) 1));
+			inv.setSelectedIndex(0);
+		}
+
 		System.out.printf("Registered player \"%s\" with id %d.%n", player.getUsername(), player.getId());
 		players.put(player.getId(), player);
 		clientHandlers.put(player.getId(), handler);
 		String joinMessage;
-		Team team = findBestTeamForNewPlayer();
-		if (team != null) {
-			player.setTeam(team);
-			System.out.printf("Player \"%s\" joined the \"%s\" team.%n", player.getUsername(), team.getName());
-			joinMessage = String.format("%s joined the %s team.", username, team.getName());
+		if (player.getTeam() != null) {
+			System.out.printf("Player \"%s\" joined the \"%s\" team.%n", player.getUsername(), player.getTeam().getName());
+			joinMessage = String.format("%s joined the %s team.", username, player.getTeam().getName());
 		} else {
 			joinMessage = username + " joined the game.";
 		}
 		player.setPosition(getBestSpawnPoint(player));
-		setMode(player, PlayerMode.NORMAL);
 		// Tell all other players that this one has joined.
 		broadcastTcpMessageToAllBut(new PlayerJoinMessage(
 				player.getId(), player.getUsername(), player.getTeam() == null ? -1 : player.getTeam().getId(),
@@ -52,11 +60,13 @@ public class PlayerManager {
 				player.getVelocity().x(), player.getVelocity().y(), player.getVelocity().z(),
 				player.getOrientation().x(), player.getOrientation().y(),
 				player.isCrouching(),
-				player.getInventory().getSelectedItemStack().getType().getId(),
+				player.getInventory().getSelectedItemStack() == null ? -1 : player.getInventory().getSelectedItemStack().getType().getId(),
 				player.getInventory().getSelectedBlockValue(),
 				player.getMode()
 		), player);
-		broadcastTcpMessageToAllBut(ChatMessage.announce(joinMessage), player);
+		if (player.getMode() != PlayerMode.SPECTATOR) {
+			broadcastTcpMessageToAllBut(ChatMessage.announce(joinMessage), player);
+		}
 		return player;
 	}
 
@@ -163,12 +173,9 @@ public class PlayerManager {
 	 */
 	public void playerKilled(ServerPlayer player, ServerPlayer killedBy) {
 		Vector3f deathPosition = new Vector3f(player.getPosition());
-		player.setPosition(getBestSpawnPoint(player));
-		player.setVelocity(new Vector3f(0));
 		player.incrementDeathCount();
-		resupply(player);
-		broadcastUdpMessage(player.getUpdateMessage(System.currentTimeMillis()));
 		broadcastUdpMessage(new SoundMessage("death", 1, deathPosition));
+		respawn(player);
 		String deathMessage;
 		if (killedBy != null) {
 			killedBy.incrementKillCount();
@@ -198,8 +205,16 @@ public class PlayerManager {
 		handler.sendTcpMessage(ChatMessage.privateMessage("You've been resupplied at your team base."));
 	}
 
+	public void respawn(ServerPlayer player) {
+		player.setPosition(getBestSpawnPoint(player));
+		player.setVelocity(new Vector3f(0));
+		broadcastUdpMessage(player.getUpdateMessage(System.currentTimeMillis()));
+		resupply(player);
+	}
+
 	public void setMode(ServerPlayer player, PlayerMode mode) {
 		player.setMode(mode);
+		var handler = getHandler(player);
 		var inv = player.getInventory();
 		inv.clear();
 		if (mode == PlayerMode.NORMAL || mode == PlayerMode.CREATIVE) {
@@ -208,7 +223,31 @@ public class PlayerManager {
 			inv.getItemStacks().add(new GunItemStack(ItemTypes.WINCHESTER));
 			inv.getItemStacks().add(new BlockItemStack(ItemTypes.BLOCK, 50, (byte) 1));
 			inv.setSelectedIndex(0);
+			handler.sendTcpMessage(new ClientInventoryMessage(inv));
+			broadcastUdpMessage(player.getUpdateMessage(System.currentTimeMillis()));
 		}
+		if (mode != PlayerMode.NORMAL) {
+			player.setTeam(null);
+			broadcastTcpMessage(new PlayerTeamUpdateMessage(player.getId(), -1));
+		} else {
+			player.setTeam(findBestTeamForNewPlayer());
+			broadcastTcpMessage(new PlayerTeamUpdateMessage(player.getId(), player.getTeam() == null ? -1 : player.getTeam().getId()));
+		}
+		handler.sendTcpMessage(ChatMessage.privateMessage("Your mode has been updated to " + mode.name() + "."));
+	}
+
+	public void setTeam(ServerPlayer player, Team team) {
+		if (Objects.equals(team, player.getTeam()) || player.getMode() != PlayerMode.NORMAL) return;
+		player.setTeam(team);
+		broadcastUdpMessage(new PlayerTeamUpdateMessage(player.getId(), team == null ? -1 : team.getId()));
+		respawn(player);
+		String chatMessage;
+		if (team != null) {
+			chatMessage = "%s has changed to the %s team.".formatted(player.getUsername(), team.getName());
+		} else {
+			chatMessage = "%s has changed to not be on a team.".formatted(player.getUsername());
+		}
+		broadcastTcpMessage(ChatMessage.announce(chatMessage));
 	}
 
 	public void handleUdpInit(DatagramInit init, DatagramPacket packet) {

server/src/main/java/nl/andrewl/aos2_server/RegistryUpdater.java

@@ -0,0 +1,59 @@
+package nl.andrewl.aos2_server;
+
+import com.google.gson.Gson;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Component that sends regular updates to any configured server registries.
+ */
+public class RegistryUpdater {
+	private final Server server;
+	private final HttpClient httpClient;
+
+	public RegistryUpdater(Server server) {
+		this.server = server;
+		this.httpClient = HttpClient.newBuilder()
+				.connectTimeout(Duration.ofSeconds(3))
+				.build();
+	}
+
+	public void sendUpdates() {
+		var cfg = server.getConfig();
+		if (
+				cfg.registries != null &&
+				cfg.registries.length > 0 &&
+				cfg.name != null && !cfg.name.isBlank()
+		) {
+			Map<String, Object> data = new HashMap<>();
+			data.put("port", cfg.port);
+			data.put("name", cfg.name);
+			data.put("description", cfg.description);
+			data.put("maxPlayers", cfg.maxPlayers);
+			data.put("currentPlayers", server.getPlayerManager().getPlayers().size());
+			String json = new Gson().toJson(data);
+			for (String registryUrl : server.getConfig().registries) {
+				HttpRequest req = HttpRequest.newBuilder(URI.create(registryUrl + "/servers"))
+						.POST(HttpRequest.BodyPublishers.ofString(json))
+						.header("Content-Type", "application/json")
+						.timeout(Duration.ofSeconds(3))
+						.build();
+				try {
+					var resp = httpClient.send(req, HttpResponse.BodyHandlers.ofString());
+					if (resp.statusCode() != 200) {
+						System.err.println("Error response when sending registry update to " + registryUrl + ": " + resp.statusCode() + " " + resp.body());
+					}
+				} catch (IOException | InterruptedException e) {
+					System.err.println("An error occurred while sending registry update to " + registryUrl + ": " + e.getMessage());
+				}
+			}
+		}
+	}
+}

server/src/main/java/nl/andrewl/aos2_server/Server.java

@@ -24,7 +24,10 @@ import java.net.*;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
+import java.util.concurrent.Executors;
 import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 
 /**
  * The central server, which mainly contains all the different managers and
@@ -83,11 +86,18 @@ public class Server implements Runnable {
 		running = true;
 		new Thread(new UdpReceiver(datagramSocket, this::handleUdpMessage)).start();
 		new Thread(worldUpdater).start();
+		ScheduledExecutorService executorService = null;
+		if (config.registries != null && config.registries.length > 0) {
+			executorService = Executors.newSingleThreadScheduledExecutor();
+			var registryUpdater = new RegistryUpdater(this);
+			executorService.scheduleAtFixedRate(registryUpdater::sendUpdates, 0, 30, TimeUnit.SECONDS);
+		}
 		System.out.printf("Started AoS2 Server on TCP/UDP port %d; now accepting connections.%n", serverSocket.getLocalPort());
 		while (running) {
 			acceptClientConnection();
 		}
 		System.out.println("Shutting down the server.");
+		if (executorService != null) executorService.shutdown();
 		playerManager.deregisterAll();
 		worldUpdater.shutdown();
 		datagramSocket.close(); // Shuts down the UdpReceiver.

server/src/main/java/nl/andrewl/aos2_server/TeamManager.java

@@ -33,6 +33,9 @@ public class TeamManager {
 		for (var team : teams.values()) {
 			if (team.getName().equals(ident)) return Optional.of(team);
 		}
+		for (var team : teams.values()) {// Try again ignoring case.
+			if (team.getName().equalsIgnoreCase(ident)) return Optional.of(team);
+		}
 		try {
 			int id = Integer.parseInt(ident);
 			for (var team : teams.values()) {

server/src/main/java/nl/andrewl/aos2_server/cli/ingame/PlayerCommandHandler.java

@@ -5,6 +5,7 @@ import nl.andrewl.aos2_server.Server;
 import nl.andrewl.aos2_server.cli.ingame.commands.KillCommand;
 import nl.andrewl.aos2_server.cli.ingame.commands.KillDeathRatioCommand;
 import nl.andrewl.aos2_server.cli.ingame.commands.PlayerModeCommand;
+import nl.andrewl.aos2_server.cli.ingame.commands.TeamsCommand;
 import nl.andrewl.aos2_server.model.ServerPlayer;
 import nl.andrewl.aos_core.net.client.ChatMessage;
 
@@ -27,6 +28,7 @@ public class PlayerCommandHandler {
 		commands.put("kd", new KillDeathRatioCommand());
 		commands.put("kill", new KillCommand());
 		commands.put("mode", new PlayerModeCommand());
+		commands.put("teams", new TeamsCommand());
 	}
 
 	public void handle(String rawCommand, ServerPlayer player, ClientCommunicationHandler handler) {

server/src/main/java/nl/andrewl/aos2_server/cli/ingame/commands/PlayerModeCommand.java

@@ -6,7 +6,6 @@ import nl.andrewl.aos2_server.cli.ingame.PlayerCommand;
 import nl.andrewl.aos2_server.model.ServerPlayer;
 import nl.andrewl.aos_core.model.PlayerMode;
 import nl.andrewl.aos_core.net.client.ChatMessage;
-import nl.andrewl.aos_core.net.client.ClientInventoryMessage;
 
 public class PlayerModeCommand implements PlayerCommand {
 	@Override
@@ -19,9 +18,6 @@ public class PlayerModeCommand implements PlayerCommand {
 		try {
 			PlayerMode mode = PlayerMode.valueOf(modeText);
 			server.getPlayerManager().setMode(player, mode);
-			handler.sendTcpMessage(new ClientInventoryMessage(player.getInventory()));
-			server.getPlayerManager().broadcastUdpMessage(player.getUpdateMessage(System.currentTimeMillis()));
-			handler.sendTcpMessage(ChatMessage.privateMessage("Your mode has been updated to " + mode.name() + "."));
 		} catch (IllegalArgumentException e) {
 			handler.sendTcpMessage(ChatMessage.privateMessage("Invalid mode. Should be NORMAL, CREATIVE, or SPECTATOR."));
 		}

server/src/main/java/nl/andrewl/aos2_server/cli/ingame/commands/TeamsCommand.java

@@ -0,0 +1,37 @@
+package nl.andrewl.aos2_server.cli.ingame.commands;
+
+import nl.andrewl.aos2_server.ClientCommunicationHandler;
+import nl.andrewl.aos2_server.Server;
+import nl.andrewl.aos2_server.cli.ingame.PlayerCommand;
+import nl.andrewl.aos2_server.model.ServerPlayer;
+import nl.andrewl.aos_core.model.Team;
+import nl.andrewl.aos_core.net.client.ChatMessage;
+
+import java.util.stream.Collectors;
+
+public class TeamsCommand implements PlayerCommand {
+	@Override
+	public void handle(String[] args, ServerPlayer player, ClientCommunicationHandler handler, Server server) {
+		if (args.length == 0) {
+			String teamsString = server.getTeamManager().getTeams().stream()
+					.map(Team::getName).collect(Collectors.joining(", "));
+			handler.sendTcpMessage(ChatMessage.privateMessage(teamsString));
+		} else {
+			String cmd = args[0].trim().toLowerCase();
+			if (cmd.equals("set")) {
+				if (args.length >= 2) {
+					String teamIdent = args[1].trim();
+					server.getTeamManager().findByIdOrName(teamIdent)
+							.ifPresentOrElse(
+									team -> server.getPlayerManager().setTeam(player, team),
+									() -> handler.sendTcpMessage(ChatMessage.privateMessage("Unknown team."))
+							);
+				} else {
+					handler.sendTcpMessage(ChatMessage.privateMessage("Missing required team identifier."));
+				}
+			} else {
+				handler.sendTcpMessage(ChatMessage.privateMessage("Unknown subcommand."));
+			}
+		}
+	}
+}

server/src/main/java/nl/andrewl/aos2_server/config/ServerConfig.java

@@ -2,6 +2,11 @@ package nl.andrewl.aos2_server.config;
 
 public class ServerConfig {
 	public int port = 25565;
+	public String name = "My Server";
+	public String description = "My server";
+	public String[] registries = new String[0];
+
+	public int maxPlayers = 32;
 	public int connectionBacklog = 5;
 	public float ticksPerSecond = 20.0f;
 	public String world = "worlds.redfort";

server/src/main/java/nl/andrewl/aos2_server/model/ServerPlayer.java

@@ -2,6 +2,8 @@ package nl.andrewl.aos2_server.model;
 
 import nl.andrewl.aos2_server.logic.PlayerActionManager;
 import nl.andrewl.aos_core.model.Player;
+import nl.andrewl.aos_core.model.PlayerMode;
+import nl.andrewl.aos_core.model.Team;
 import nl.andrewl.aos_core.model.item.Inventory;
 import nl.andrewl.aos_core.net.client.PlayerUpdateMessage;
 
@@ -24,8 +26,8 @@ public class ServerPlayer extends Player {
 	private int deathCount;
 	private int killCount;
 
-	public ServerPlayer(int id, String username) {
-		super(id, username);
+	public ServerPlayer(int id, String username, Team team, PlayerMode mode) {
+		super(id, username, team, mode);
 		this.inventory = new Inventory(new ArrayList<>(), 0);
 		this.health = 1f;
 		this.actionManager = new PlayerActionManager(this);

server/src/main/resources/default-config.yaml

@@ -1,5 +1,10 @@
 # Ace of Shades 2 Server Configuration
 port: 25565
+name: My Server
+description: This is my Ace of Shades server.
+registries:
+  - https://reg.aos2.net
+maxPlayers: 32
 connectionBacklog: 5
 ticksPerSecond: 20.0
 world: worlds.redfort