Add extensions command

core/src/main/java/org/geysermc/geyser/command/GeyserCommandManager.java

@@ -63,6 +63,7 @@ public abstract class GeyserCommandManager extends CommandManager {
         register(new StatisticsCommand(geyser, "statistics", "geyser.commands.statistics.desc", "geyser.command.statistics"));
         register(new AdvancementsCommand("advancements", "geyser.commands.advancements.desc", "geyser.command.advancements"));
         register(new AdvancedTooltipsCommand("tooltips", "geyser.commands.advancedtooltips.desc", "geyser.command.tooltips"));
+        register(new ExtensionsCommand(geyser, "extensions", "geyser.commands.extensions.desc", "geyser.command.extensions"));
         if (GeyserImpl.getInstance().getPlatformType() == PlatformType.STANDALONE) {
             register(new StopCommand(geyser, "stop", "geyser.commands.stop.desc", "geyser.command.stop"));
         }

core/src/main/java/org/geysermc/geyser/command/defaults/ExtensionsCommand.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2019-2022 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.command.defaults;
+
+import org.geysermc.geyser.GeyserImpl;
+import org.geysermc.geyser.api.extension.Extension;
+import org.geysermc.geyser.command.GeyserCommand;
+import org.geysermc.geyser.command.GeyserCommandSource;
+import org.geysermc.geyser.session.GeyserSession;
+import org.geysermc.geyser.text.ChatColor;
+import org.geysermc.geyser.text.GeyserLocale;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Comparator;
+import java.util.List;
+
+public class ExtensionsCommand extends GeyserCommand {
+    private final GeyserImpl geyser;
+
+    public ExtensionsCommand(GeyserImpl geyser, String name, String description, String permission) {
+        super(name, description, permission);
+
+        this.geyser = geyser;
+    }
+
+    @Override
+    public void execute(@Nullable GeyserSession session, GeyserCommandSource sender, String[] args) {
+        // TODO: Pagination
+        int page = 1;
+        int maxPage = 1;
+        String header = GeyserLocale.getPlayerLocaleString("geyser.commands.extensions.header", sender.locale(), page, maxPage);
+        sender.sendMessage(header);
+
+        this.geyser.extensionManager().extensions().stream().sorted(Comparator.comparing(Extension::name)).forEach(extension -> {
+            String extensionName = (extension.isEnabled() ? ChatColor.GREEN : ChatColor.RED) + extension.name();
+            sender.sendMessage("- " + extensionName + ChatColor.RESET + " v" + extension.description().version() + formatAuthors(extension.description().authors()));
+        });
+    }
+
+    private String formatAuthors(List<String> authors) {
+        return authors.isEmpty() ? "" : " by: " + String.join(", ", authors);
+    }
+}