feat: support setting up 1.21+ server links

Adds support for setting up server links in pause menu on supported clients (1.21+). Works on both modern, and 1.8-based servers using ViaVersion.

Signed-off-by: TTtie <me@tttie.cz>

Author: TTtie

core/src/main/java/dev/pgm/community/feature/FeatureManager.java

@@ -24,6 +24,7 @@
 import dev.pgm.community.polls.feature.PollFeature;
 import dev.pgm.community.requests.feature.RequestFeature;
 import dev.pgm.community.requests.feature.types.SQLRequestFeature;
+import dev.pgm.community.serverlinks.ServerLinksFeature;
 import dev.pgm.community.sessions.feature.SessionFeature;
 import dev.pgm.community.sessions.feature.types.SQLSessionFeature;
 import dev.pgm.community.squads.SquadFeature;
@@ -60,6 +61,7 @@ public class FeatureManager {
   private final PollFeature polls;
   private final SquadFeature squads;
   private final MatchHistoryFeature history;
+  private final ServerLinksFeature serverLinks;
 
   public FeatureManager(
       Configuration config,
@@ -97,6 +99,7 @@ public FeatureManager(
     this.polls = new PollFeature(config, logger);
     this.squads = new SquadFeature(config, logger);
     this.history = new MatchHistoryFeature(config, logger);
+    this.serverLinks = new ServerLinksFeature(config, logger);
   }
 
   public AssistanceFeature getReports() {
@@ -179,6 +182,10 @@ public MatchHistoryFeature getHistory() {
     return history;
   }
 
+  public ServerLinksFeature getServerLinks() {
+    return serverLinks;
+  }
+
   public void reloadConfig(Configuration config) {
     // Reload all config values here
     getReports().getConfig().reload(config);
@@ -200,6 +207,7 @@ public void reloadConfig(Configuration config) {
     getPolls().getConfig().reload(config);
     getSquads().getConfig().reload(config);
     getHistory().getConfig().reload(config);
+    getServerLinks().getConfig().reload(config);
 
     // TODO: Look into maybe unregister commands for features that have been disabled
     // commands#unregisterCommand
@@ -226,5 +234,6 @@ public void disable() {
     if (getPolls().isEnabled()) getPolls().disable();
     if (getSquads().isEnabled()) getSquads().disable();
     if (getHistory().isEnabled()) getHistory().disable();
+    if (getServerLinks().isEnabled()) getServerLinks().disable();
   }
 }

core/src/main/java/dev/pgm/community/serverlinks/ServerLinksConfig.java

@@ -0,0 +1,65 @@
+package dev.pgm.community.serverlinks;
+
+import static tc.oc.pgm.util.text.TextParser.parseComponent;
+import static tc.oc.pgm.util.text.TextParser.parseEnum;
+import static tc.oc.pgm.util.text.TextParser.parseUri;
+
+import dev.pgm.community.feature.config.FeatureConfigImpl;
+import dev.pgm.community.serverlinks.types.ServerLink;
+import dev.pgm.community.serverlinks.types.ServerLinkBuiltinType;
+import java.net.URI;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import org.bukkit.configuration.Configuration;
+
+public class ServerLinksConfig extends FeatureConfigImpl {
+  private static final String KEY = "server-links";
+  private static final String LINKS_KEY = "links";
+
+  private static final String LINK_BUILTIN_KEY = "builtin";
+  private static final String LINK_CUSTOM_TEXT_KEY = "text";
+  private static final String LINK_URI_KEY = "uri";
+
+  private List<ServerLink> links;
+
+  public ServerLinksConfig(Configuration config) {
+    super(KEY, config);
+  }
+
+  public List<ServerLink> getLinks() {
+    return links;
+  }
+
+  @Override
+  public void reload(Configuration config) {
+    super.reload(config);
+    links = config.getMapList(getKey() + "." + LINKS_KEY).stream()
+        .map(this::readLink)
+        .toList();
+  }
+
+  private ServerLink readLink(Map<?, ?> configData) {
+    String builtIn = Objects.toString(configData.get(LINK_BUILTIN_KEY), null);
+    String customText = Objects.toString(configData.get(LINK_CUSTOM_TEXT_KEY), null);
+    String uri = Objects.toString(configData.get(LINK_URI_KEY), null);
+
+    if (builtIn == null && customText == null) {
+      throw new IllegalStateException(
+          "A server link must have either built-in or custom text defined");
+    } else if (builtIn != null && customText != null) {
+      throw new IllegalStateException(
+          "A server link cannot have both built-in and custom text defined");
+    }
+
+    URI parsedUri = parseUri(uri);
+    if (!parsedUri.getScheme().equals("http") && !parsedUri.getScheme().equals("https")) {
+      throw new IllegalStateException("The URL " + uri + " is not a web URL");
+    }
+
+    return new ServerLink(
+        builtIn != null ? parseEnum(builtIn, ServerLinkBuiltinType.class) : null,
+        customText != null ? parseComponent(customText) : null,
+        parsedUri);
+  }
+}

core/src/main/java/dev/pgm/community/serverlinks/ServerLinksFeature.java

@@ -0,0 +1,44 @@
+package dev.pgm.community.serverlinks;
+
+import dev.pgm.community.feature.FeatureBase;
+import dev.pgm.community.serverlinks.types.ServerLink;
+import dev.pgm.community.util.Platform;
+import java.util.List;
+import java.util.logging.Logger;
+import org.bukkit.configuration.Configuration;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.player.PlayerJoinEvent;
+
+public class ServerLinksFeature extends FeatureBase {
+  private static final ServerLinksPlatform PLATFORM = Platform.get(ServerLinksPlatform.class);
+
+  public interface ServerLinksPlatform {
+    default boolean isSupported() {
+      return true;
+    }
+
+    void sendToPlayer(Player player, List<ServerLink> serverLinks);
+  }
+
+  public ServerLinksFeature(Configuration config, Logger logger) {
+    super(new ServerLinksConfig(config), logger, "Server Links");
+
+    if (getConfig().isEnabled()) {
+      if (!PLATFORM.isSupported()) {
+        logger.warning("Server links are enabled but not supported by the platform");
+        return;
+      }
+      enable();
+    }
+  }
+
+  @EventHandler
+  public void onPlayerJoin(PlayerJoinEvent event) {
+    PLATFORM.sendToPlayer(event.getPlayer(), getServerLinksConfig().getLinks());
+  }
+
+  public ServerLinksConfig getServerLinksConfig() {
+    return (ServerLinksConfig) getConfig();
+  }
+}

core/src/main/java/dev/pgm/community/serverlinks/types/ServerLink.java

@@ -0,0 +1,13 @@
+package dev.pgm.community.serverlinks.types;
+
+import java.net.URI;
+import net.kyori.adventure.text.Component;
+
+/**
+ * Represents a Minecraft server link.
+ *
+ * @param builtinType The built-in type of the server link, or null if it's a custom link.
+ * @param customText The custom text for the server link, or null if builtinType is set.
+ * @param uri The URI of the server link.
+ */
+public record ServerLink(ServerLinkBuiltinType builtinType, Component customText, URI uri) {}

core/src/main/java/dev/pgm/community/serverlinks/types/ServerLinkBuiltinType.java

@@ -0,0 +1,18 @@
+package dev.pgm.community.serverlinks.types;
+
+/**
+ * Represents a built-in server link type that will be auto-translated by the Minecraft client and
+ * possibly have special functionality. Keep in sync with Paper's org.bukkit.ServerLinks.Type.
+ */
+public enum ServerLinkBuiltinType {
+  REPORT_BUG,
+  COMMUNITY_GUIDELINES,
+  SUPPORT,
+  STATUS,
+  FEEDBACK,
+  COMMUNITY,
+  WEBSITE,
+  FORUMS,
+  NEWS,
+  ANNOUNCEMENTS;
+}

core/src/main/resources/config.yml

@@ -385,3 +385,15 @@ database:
   host: "localhost:3306" # host and port
   timezone: "America/Los_Angeles" # Database timezone
   max-connections: 2 # Maximum simultaneous connections (does not impact SQLite)
+
+# Server Links - Adds links to the pause menu for 1.21+ clients
+# Requires ViaVersion to be installed on 1.8-based servers.
+server-links:
+  enabled: false
+  links:
+    # A built-in server link type will be auto-translated by the client and may provide some extra functionality.
+    - builtin: report bug # See https://jd.papermc.io/paper/org/bukkit/ServerLinks.Type.html for a list of built-in types
+      uri: https://pgm.dev
+    # Alternatively, custom text can be provided. Custom text is mutually exclusive with built-in types.
+    - text: "Submit a new map"
+      uri: https://pgm.dev

core/src/main/resources/plugin.yml

@@ -4,4 +4,4 @@ main: ${mainClass}
 version: ${version} (git-${commitHash})
 website: ${url}
 author: ${author}
-softdepend: [PGM, Environment, AFK]
+softdepend: [PGM, Environment, AFK, ViaVersion]

platform/platform-modern/src/main/java/dev/pgm/community/platform/modern/feature/ModernServerLinksPlatform.java

@@ -0,0 +1,37 @@
+package dev.pgm.community.platform.modern.feature;
+
+import static dev.pgm.community.util.Supports.Variant.PAPER;
+
+import dev.pgm.community.serverlinks.ServerLinksFeature;
+import dev.pgm.community.serverlinks.types.ServerLink;
+import dev.pgm.community.serverlinks.types.ServerLinkBuiltinType;
+import dev.pgm.community.util.Supports;
+import java.util.List;
+import org.bukkit.ServerLinks;
+import org.bukkit.craftbukkit.CraftServerLinks;
+import org.bukkit.entity.Player;
+
+@Supports(PAPER)
+public class ModernServerLinksPlatform implements ServerLinksFeature.ServerLinksPlatform {
+  @Override
+  public void sendToPlayer(Player player, List<ServerLink> serverLinks) {
+    player.sendLinks(toPlatformServerLinks(serverLinks));
+  }
+
+  private ServerLinks toPlatformServerLinks(List<ServerLink> links) {
+    ServerLinks bukkitLinks = new CraftServerLinks(new net.minecraft.server.ServerLinks(List.of()));
+    for (ServerLink link : links) {
+      if (link.builtinType() != null) {
+        bukkitLinks.addLink(toBukkitType(link.builtinType()), link.uri());
+      } else {
+        bukkitLinks.addLink(link.customText(), link.uri());
+      }
+    }
+
+    return bukkitLinks;
+  }
+
+  private ServerLinks.Type toBukkitType(ServerLinkBuiltinType type) {
+    return ServerLinks.Type.values()[type.ordinal()];
+  }
+}

platform/platform-sportpaper/build.gradle.kts

@@ -6,4 +6,5 @@ dependencies {
     implementation(project(":core"))
     implementation(project(":util"))
     compileOnly("app.ashcon:sportpaper:1.8.8-R0.1-SNAPSHOT")
+    compileOnly("com.viaversion:viaversion-api:5.0.0")
 }

platform/platform-sportpaper/src/main/java/dev/pgm/community/platform/sportpaper/features/SpServerLinksPlatform.java

@@ -0,0 +1,86 @@
+package dev.pgm.community.platform.sportpaper.features;
+
+import static dev.pgm.community.util.Supports.Variant.SPORTPAPER;
+
+import com.viaversion.nbt.tag.Tag;
+import com.viaversion.viaversion.api.Via;
+import com.viaversion.viaversion.api.connection.UserConnection;
+import com.viaversion.viaversion.api.protocol.Protocol;
+import com.viaversion.viaversion.api.protocol.packet.PacketWrapper;
+import com.viaversion.viaversion.api.protocol.packet.State;
+import com.viaversion.viaversion.api.protocol.version.ProtocolVersion;
+import com.viaversion.viaversion.api.type.Types;
+import com.viaversion.viaversion.libs.gson.JsonParser;
+import com.viaversion.viaversion.libs.mcstructs.text.utils.JsonNbtConverter;
+import dev.pgm.community.serverlinks.ServerLinksFeature;
+import dev.pgm.community.serverlinks.types.ServerLink;
+import dev.pgm.community.util.Supports;
+import java.util.List;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.gson.GsonComponentSerializer;
+import org.bukkit.entity.Player;
+
+@Supports(SPORTPAPER)
+public class SpServerLinksPlatform implements ServerLinksFeature.ServerLinksPlatform {
+  private final Protocol<?, ?, ?, ?> serverLinkProtocol = findServerLinkProtocol();
+  private static final boolean hasVia = hasVia();
+
+  private static boolean hasVia() {
+    try {
+      Class.forName("com.viaversion.viaversion.api.Via");
+      return true;
+    } catch (ClassNotFoundException e) {
+      return false;
+    }
+  }
+
+  @Override
+  public boolean isSupported() {
+    return hasVia;
+  }
+
+  @Override
+  public void sendToPlayer(Player player, List<ServerLink> serverLinks) {
+    if (hasVia && Via.getAPI().isInjected(player.getUniqueId())) {
+      UserConnection userConnection = Via.getAPI().getConnection(player.getUniqueId());
+      if (userConnection != null
+          && userConnection
+              .getProtocolInfo()
+              .protocolVersion()
+              .newerThanOrEqualTo(ProtocolVersion.v1_21)) {
+        PacketWrapper serverLinksPacket = createPacket(userConnection, serverLinks);
+        serverLinksPacket.scheduleSend(serverLinkProtocol.getClass());
+      }
+    }
+  }
+
+  private PacketWrapper createPacket(UserConnection conn, List<ServerLink> links) {
+    var packetTypes = serverLinkProtocol.getPacketTypesProvider().mappedClientboundPacketTypes();
+    var packetType = packetTypes.get(State.PLAY).typeByName("SERVER_LINKS");
+    PacketWrapper packet = PacketWrapper.create(packetType, conn);
+    packet.write(Types.VAR_INT, links.size());
+    // TODO: is there a better way to do this?
+    for (ServerLink link : links) {
+      packet.write(Types.BOOLEAN, link.builtinType() != null);
+      if (link.builtinType() != null) {
+        packet.write(Types.VAR_INT, link.builtinType().ordinal());
+      } else {
+        packet.write(Types.TAG, toViaTag(link.customText()));
+      }
+      packet.write(Types.STRING, link.uri().toString());
+    }
+
+    return packet;
+  }
+
+  private Tag toViaTag(Component component) {
+    return JsonNbtConverter.toNbt(
+        JsonParser.parseString(GsonComponentSerializer.gson().serialize(component)));
+  }
+
+  private Protocol<?, ?, ?, ?> findServerLinkProtocol() {
+    return Via.getManager()
+        .getProtocolManager()
+        .getProtocol(/* to */ ProtocolVersion.v1_21, /* from */ ProtocolVersion.v1_20_5);
+  }
+}