Improve help command with better formatting.

src/main/java/com/onarandombox/MultiverseCore/commandTools/MVCommandCompletions.java

@@ -8,7 +8,11 @@
 package com.onarandombox.MultiverseCore.commandTools;
 
 import co.aikar.commands.BukkitCommandCompletionContext;
+import co.aikar.commands.BukkitCommandExecutionContext;
+import co.aikar.commands.CommandIssuer;
 import co.aikar.commands.PaperCommandCompletions;
+import co.aikar.commands.RegisteredCommand;
+import co.aikar.commands.RootCommand;
 import com.dumptruckman.minecraft.util.Logging;
 import com.onarandombox.MultiverseCore.MVWorld;
 import com.onarandombox.MultiverseCore.MultiverseCore;
@@ -31,6 +35,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -51,6 +56,7 @@ public class MVCommandCompletions extends PaperCommandCompletions {
         this.plugin = plugin;
         this.worldManager = plugin.getMVWorldManager();
 
+        registerAsyncCompletion("subCommands", this::suggestSubCommands);
         registerAsyncCompletion("MVWorlds", this::suggestMVWorlds);
         registerAsyncCompletion("unloadedWorlds", this::suggestUnloadedWorlds);
         registerAsyncCompletion("potentialWorlds", this::suggestPotentialWorlds);
@@ -67,6 +73,37 @@ public class MVCommandCompletions extends PaperCommandCompletions {
         registerStaticCompletion("toggles", this::suggestToggles);
     }
 
+    @NotNull
+    private Collection<String> suggestSubCommands(@NotNull BukkitCommandCompletionContext context) {
+        String rootCmdName = context.getConfig();
+        if (rootCmdName == null) {
+            return Collections.emptyList();
+        }
+
+        RootCommand rootCommand = this.plugin.getMVCommandManager().getRegisteredRootCommands().stream()
+                .unordered()
+                .filter(c -> c.getCommandName().equals(rootCmdName))
+                .findFirst()
+                .orElse(null);
+
+        if (rootCommand == null) {
+            return Collections.emptyList();
+        }
+
+        return rootCommand.getSubCommands().entries().stream()
+                .unordered()
+                .filter(entry -> checkPerms(context.getIssuer(), entry.getValue()))
+                .map(Map.Entry::getKey)
+                .filter(cmdName -> !cmdName.startsWith("__"))
+                .collect(Collectors.toList());
+    }
+
+    private boolean checkPerms(@NotNull CommandIssuer issuer,
+                               @NotNull RegisteredCommand<?> cmd) {
+
+        return this.plugin.getMVCommandManager().hasPermission(issuer, cmd.getRequiredPermissions());
+    }
+
     @NotNull
     private Collection<String> suggestToggles() {
         return Arrays.asList("on", "off");
@@ -139,6 +176,7 @@ public class MVCommandCompletions extends PaperCommandCompletions {
         return Arrays.asList("~", df.format(coordValue));
     }
 
+    @NotNull
     private Collection<String> suggestDestinations(@NotNull BukkitCommandCompletionContext context) {
         return this.plugin.getDestFactory().getIdentifiers().parallelStream()
                 .unordered()
@@ -147,6 +185,7 @@ public class MVCommandCompletions extends PaperCommandCompletions {
                 .collect(Collectors.toList());
     }
 
+    @NotNull
     private Collection<String> suggestAnchors(@NotNull BukkitCommandCompletionContext context) {
         return this.plugin.getAnchorManager().getAnchors(context.getPlayer());
     }

src/main/java/com/onarandombox/MultiverseCore/commandTools/MVCommandManager.java

@@ -11,7 +11,9 @@ import co.aikar.commands.BukkitCommandCompletionContext;
 import co.aikar.commands.BukkitCommandExecutionContext;
 import co.aikar.commands.CommandCompletions;
 import co.aikar.commands.CommandContexts;
+import co.aikar.commands.CommandHelp;
 import co.aikar.commands.CommandIssuer;
+import co.aikar.commands.HelpEntry;
 import co.aikar.commands.PaperCommandManager;
 import com.onarandombox.MultiverseCore.MultiverseCore;
 import com.onarandombox.MultiverseCore.commands.AnchorCommand;
@@ -52,6 +54,7 @@ import org.bukkit.plugin.PluginDescriptionFile;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Arrays;
+import java.util.List;
 import java.util.Set;
 import java.util.regex.Pattern;
 
@@ -69,6 +72,7 @@ public class MVCommandManager extends PaperCommandManager {
         new MVCommandConditions(plugin, getCommandConditions());
 
         enableUnstableAPI("help");
+        setDefaultHelpPerPage(6);
 
         registerCommand(new UsageCommand(this.plugin));
         registerCommand(new CreateCommand(this.plugin));
@@ -163,6 +167,17 @@ public class MVCommandManager extends PaperCommandManager {
         return commandQueueManager;
     }
 
+    public void showUsage(@NotNull CommandHelp help) {
+        List<HelpEntry> entries = help.getHelpEntries();
+
+        if (entries.size() == 1) {
+            this.plugin.getMVCommandManager().getHelpFormatter().showDetailedHelp(help, entries.get(0));
+            return;
+        }
+
+        help.showHelp();
+    }
+
     public void showPluginInfo(@NotNull CommandSender sender,
                                @NotNull PluginDescriptionFile description,
                                @NotNull ColourAlternator colour,

src/main/java/com/onarandombox/MultiverseCore/commands/UsageCommand.java

@@ -8,7 +8,13 @@
 package com.onarandombox.MultiverseCore.commands;
 
 import co.aikar.commands.CommandHelp;
-import co.aikar.commands.annotation.*;
+import co.aikar.commands.annotation.CommandAlias;
+import co.aikar.commands.annotation.CommandCompletion;
+import co.aikar.commands.annotation.CommandPermission;
+import co.aikar.commands.annotation.Description;
+import co.aikar.commands.annotation.HelpCommand;
+import co.aikar.commands.annotation.Subcommand;
+import co.aikar.commands.annotation.Syntax;
 import com.onarandombox.MultiverseCore.MultiverseCore;
 import org.bukkit.command.CommandSender;
 import org.jetbrains.annotations.NotNull;
@@ -20,16 +26,15 @@ public class UsageCommand extends MultiverseCommand {
         super(plugin);
     }
 
-    @Subcommand("help")
     @HelpCommand
+    @Subcommand("help")
     @CommandPermission("multiverse.core.help")
     @Syntax("[filter] [page]")
-    @Description("Show Multiverse Command usage.")
+    @CommandCompletion("@subCommands:mv")
+    @Description("Show Multiverse-Core Command usage.")
     public void onUsageCommand(@NotNull CommandSender sender,
                                @NotNull CommandHelp help) {
 
-        //TODO ACF: Proper formatting and paging.
-        help.setPerPage(6);
-        help.showHelp();
+        this.plugin.getMVCommandManager().showUsage(help);
     }
 }