Expose CommandMeta in CommandManager and add a ref to the plugin instance (#544)

api/src/main/java/com/velocitypowered/api/command/CommandManager.java

@@ -10,6 +10,7 @@ package com.velocitypowered.api.command;
 import com.velocitypowered.api.event.command.CommandExecuteEvent;
 import java.util.Collection;
 import java.util.concurrent.CompletableFuture;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Handles the registration and execution of commands.
@@ -74,6 +75,13 @@ public interface CommandManager {
    */
   void unregister(String alias);
 
+  /**
+   * Retrieves the {@link CommandMeta} from the specified command alias, if registered.
+   * @param alias the command alias to lookup
+   * @return an {@link CommandMeta} of the alias
+   */
+  @Nullable CommandMeta getCommandMeta(String alias);
+
   /**
    * Attempts to asynchronously execute a command from the given {@code cmdLine}.
    *

api/src/main/java/com/velocitypowered/api/command/CommandMeta.java

@@ -9,6 +9,7 @@ package com.velocitypowered.api.command;
 
 import com.mojang.brigadier.tree.CommandNode;
 import java.util.Collection;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * Contains metadata for a {@link Command}.
@@ -32,6 +33,14 @@ public interface CommandMeta {
    */
   Collection<CommandNode<CommandSource>> getHints();
 
+  /**
+   * Returns the plugin who registered the command.
+   * Note some {@link Command} registrations may not provide this information.
+   *
+   * @return the registering plugin
+   */
+  @Nullable Object getPlugin();
+
   /**
    * Provides a fluent interface to create {@link CommandMeta}s.
    */
@@ -56,6 +65,14 @@ public interface CommandMeta {
      */
     Builder hint(CommandNode<CommandSource> node);
 
+    /**
+     * Specifies the plugin who registers the {@link Command}.
+     *
+     * @param plugin the registering plugin
+     * @return this builder, for chaining
+     */
+    Builder plugin(Object plugin);
+
     /**
      * Returns a newly-created {@link CommandMeta} based on the specified parameters.
      *

proxy/src/main/java/com/velocitypowered/proxy/command/VelocityCommandManager.java

@@ -42,7 +42,9 @@ import com.velocitypowered.proxy.event.VelocityEventManager;
 import java.util.Collection;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.stream.Collectors;
@@ -50,6 +52,7 @@ import net.kyori.adventure.identity.Identity;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.format.NamedTextColor;
 import org.checkerframework.checker.lock.qual.GuardedBy;
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.jetbrains.annotations.VisibleForTesting;
 
 public class VelocityCommandManager implements CommandManager {
@@ -61,6 +64,7 @@ public class VelocityCommandManager implements CommandManager {
   private final List<CommandRegistrar<?>> registrars;
   private final SuggestionsProvider<CommandSource> suggestionsProvider;
   private final CommandGraphInjector<CommandSource> injector;
+  private final Map<String, CommandMeta> commandMetas;
 
   /**
    * Constructs a command manager.
@@ -78,6 +82,7 @@ public class VelocityCommandManager implements CommandManager {
             new RawCommandRegistrar(root, this.lock.writeLock()));
     this.suggestionsProvider = new SuggestionsProvider<>(this.dispatcher, this.lock.readLock());
     this.injector = new CommandGraphInjector<>(this.dispatcher, this.lock.readLock());
+    this.commandMetas = new ConcurrentHashMap<>();
   }
 
   public void setAnnounceProxyCommands(boolean announceProxyCommands) {
@@ -137,6 +142,9 @@ public class VelocityCommandManager implements CommandManager {
       return false;
     }
     registrar.register(meta, superInterface.cast(command));
+    for (String alias : meta.getAliases()) {
+      commandMetas.put(alias, meta);
+    }
     return true;
   }
 
@@ -148,11 +156,24 @@ public class VelocityCommandManager implements CommandManager {
       // The literals of secondary aliases will preserve the children of
       // the removed literal in the graph.
       dispatcher.getRoot().removeChildByName(alias.toLowerCase(Locale.ENGLISH));
+
+      CommandMeta meta = commandMetas.get(alias);
+      if (meta != null) {
+        for (String metaAlias : meta.getAliases()) {
+          commandMetas.remove(metaAlias, meta);
+        }
+      }
     } finally {
       lock.writeLock().unlock();
     }
   }
 
+  @Override
+  public @Nullable CommandMeta getCommandMeta(String alias) {
+    Preconditions.checkNotNull(alias, "alias");
+    return commandMetas.get(alias);
+  }
+
   /**
    * Fires a {@link CommandExecuteEvent}.
    *

proxy/src/main/java/com/velocitypowered/proxy/command/VelocityCommandMeta.java

@@ -30,6 +30,8 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Set;
 import java.util.stream.Stream;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 public final class VelocityCommandMeta implements CommandMeta {
 
@@ -37,12 +39,14 @@ public final class VelocityCommandMeta implements CommandMeta {
 
     private final ImmutableSet.Builder<String> aliases;
     private final ImmutableList.Builder<CommandNode<CommandSource>> hints;
+    private @MonotonicNonNull Object plugin;
 
     public Builder(final String alias) {
       Preconditions.checkNotNull(alias, "alias");
       this.aliases = ImmutableSet.<String>builder()
               .add(alias.toLowerCase(Locale.ENGLISH));
       this.hints = ImmutableList.builder();
+      this.plugin = null;
     }
 
     @Override
@@ -69,9 +73,16 @@ public final class VelocityCommandMeta implements CommandMeta {
       return this;
     }
 
+    @Override
+    public CommandMeta.Builder plugin(Object plugin) {
+      Preconditions.checkNotNull(plugin, "plugin");
+      this.plugin = plugin;
+      return this;
+    }
+
     @Override
     public CommandMeta build() {
-      return new VelocityCommandMeta(this.aliases.build(), this.hints.build());
+      return new VelocityCommandMeta(this.aliases.build(), this.hints.build(), this.plugin);
     }
   }
 
@@ -111,11 +122,16 @@ public final class VelocityCommandMeta implements CommandMeta {
 
   private final Set<String> aliases;
   private final List<CommandNode<CommandSource>> hints;
+  private final Object plugin;
 
   private VelocityCommandMeta(
-          final Set<String> aliases, final List<CommandNode<CommandSource>> hints) {
+          final Set<String> aliases,
+          final List<CommandNode<CommandSource>> hints,
+          final @Nullable Object plugin
+  ) {
     this.aliases = aliases;
     this.hints = hints;
+    this.plugin = plugin;
   }
 
   @Override
@@ -128,6 +144,11 @@ public final class VelocityCommandMeta implements CommandMeta {
     return this.hints;
   }
 
+  @Override
+  public @Nullable Object getPlugin() {
+    return plugin;
+  }
+
   @Override
   public boolean equals(final Object o) {
     if (this == o) {