Brigadier based command API

Co-authored-by: Jake Potrebic <jake.m.potrebic@gmail.com>

paper-api/src/main/java/org/bukkit/command/Command.java

@@ -520,4 +520,9 @@ public abstract class Command {
     public String toString() {
         return getClass().getName() + '(' + name + ')';
     }
+
+    // Paper start
+    @org.jetbrains.annotations.ApiStatus.Internal
+    public boolean canBeOverriden() { return false; }
+    // Paper end
 }

paper-api/src/main/java/org/bukkit/command/FormattedCommandAlias.java

@@ -117,7 +117,7 @@ public class FormattedCommandAlias extends Command {
             index = formatString.indexOf('$', index);
         }
 
-        return formatString;
+        return formatString.trim(); // Paper - Causes an extra space at the end, breaks with brig commands
     }
 
     @NotNull

paper-api/src/main/java/org/bukkit/command/SimpleCommandMap.java

@@ -23,10 +23,14 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class SimpleCommandMap implements CommandMap {
-    protected final Map<String, Command> knownCommands = new HashMap<String, Command>();
+    protected final Map<String, Command> knownCommands; // Paper
     private final Server server;
 
-    public SimpleCommandMap(@NotNull final Server server) {
+    // Paper start
+    @org.jetbrains.annotations.ApiStatus.Internal
+    public SimpleCommandMap(@NotNull final Server server, Map<String, Command> backing) {
+        this.knownCommands = backing;
+    // Paper end
         this.server = server;
         setDefaultCommands();
     }
@@ -103,7 +107,10 @@ public class SimpleCommandMap implements CommandMap {
      */
     private synchronized boolean register(@NotNull String label, @NotNull Command command, boolean isAlias, @NotNull String fallbackPrefix) {
         knownCommands.put(fallbackPrefix + ":" + label, command);
-        if ((command instanceof BukkitCommand || isAlias) && knownCommands.containsKey(label)) {
+        // Paper start
+        Command known = knownCommands.get(label);
+        if ((command instanceof BukkitCommand || isAlias) && (known != null && !known.canBeOverriden())) {
+        // Paper end
             // Request is for an alias/fallback command and it conflicts with
             // a existing command or previous alias ignore it
             // Note: This will mean it gets removed from the commands list of active aliases
@@ -115,7 +122,9 @@ public class SimpleCommandMap implements CommandMap {
         // If the command exists but is an alias we overwrite it, otherwise we return
         Command conflict = knownCommands.get(label);
         if (conflict != null && conflict.getLabel().equals(label)) {
+            if (!conflict.canBeOverriden()) { // Paper
             return false;
+            } // Paper
         }
 
         if (!isAlias) {

paper-api/src/main/java/org/bukkit/command/defaults/ReloadCommand.java

@@ -18,6 +18,9 @@ public class ReloadCommand extends BukkitCommand {
         this.setAliases(Arrays.asList("rl"));
     }
 
+    @org.jetbrains.annotations.ApiStatus.Internal // Paper
+    public static final String RELOADING_DISABLED_MESSAGE = "A lifecycle event handler has been registered which makes reloading plugins not possible"; // Paper
+
     @Override
     public boolean execute(@NotNull CommandSender sender, @NotNull String currentAlias, @NotNull String[] args) { // Paper
         if (!testPermission(sender)) return true;
@@ -51,7 +54,16 @@ public class ReloadCommand extends BukkitCommand {
 
         Command.broadcastCommandMessage(sender, ChatColor.RED + "Please note that this command is not supported and may cause issues when using some plugins.");
         Command.broadcastCommandMessage(sender, ChatColor.RED + "If you encounter any issues please use the /stop command to restart your server.");
-        Bukkit.reload();
+        // Paper start - lifecycle events
+        try {
+            Bukkit.reload();
+        } catch (final IllegalStateException ex) {
+            if (ex.getMessage().equals(RELOADING_DISABLED_MESSAGE)) {
+                Command.broadcastCommandMessage(sender, ChatColor.RED + RELOADING_DISABLED_MESSAGE);
+                return true;
+            }
+        }
+        // Paper end - lifecycle events
         Command.broadcastCommandMessage(sender, ChatColor.GREEN + "Reload complete.");
 
         return true;

paper-api/src/main/java/org/bukkit/event/server/TabCompleteEvent.java

@@ -18,6 +18,8 @@ import org.jetbrains.annotations.NotNull;
  * themselves. Plugins wishing to remove commands from tab completion are
  * advised to ensure the client does not have permission for the relevant
  * commands, or use {@link PlayerCommandSendEvent}.
+ * @apiNote Only called for bukkit API commands {@link org.bukkit.command.Command} and
+ * {@link org.bukkit.command.CommandExecutor} and not for brigadier commands ({@link io.papermc.paper.command.brigadier.Commands}).
  */
 public class TabCompleteEvent extends Event implements Cancellable {