From 8a9e74f57f7f774225415163916c8f12b6efcb4d Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 26 Nov 2017 13:19:58 -0500
Subject: [PATCH] AsyncTabCompleteEvent

Let plugins be able to control tab completion of commands and chat async.

This will be useful for frameworks like ACF so we can define async safe completion handlers,
and avoid going to main for tab completions.

Especially useful if you need to query a database in order to obtain the results for tab
completion, such as offline players.

Also adds isCommand and getLocation to the sync TabCompleteEvent

diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 62b7f24b5a..d44ac990b4 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -508,10 +508,10 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
     }
 
     public void a(PacketPlayInTabComplete packetplayintabcomplete) {
-        PlayerConnectionUtils.ensureMainThread(packetplayintabcomplete, this, this.player.getWorldServer());
+        // PlayerConnectionUtils.ensureMainThread(packetplayintabcomplete, this, this.player.getWorldServer()); // Paper - run this async
         // CraftBukkit start
         if (chatSpamField.addAndGet(this, 1) > 500 && !this.minecraftServer.getPlayerList().isOp(this.player.getProfile())) {
-            this.disconnect(new ChatMessage("disconnect.spam", new Object[0]));
+            minecraftServer.postToMainThread(() -> this.disconnect(new ChatMessage("disconnect.spam", new Object[0]))); // Paper
             return;
         }
         // CraftBukkit end
@@ -521,12 +521,34 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
             stringreader.skip();
         }
 
+        // Paper start - async tab completion
+        com.destroystokyo.paper.event.server.AsyncTabCompleteEvent event;
+        java.util.List<String> completions = new java.util.ArrayList<>();
+        String buffer = packetplayintabcomplete.c();
+        event = new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(this.getPlayer(), completions,
+                buffer, true, null);
+        event.callEvent();
+        completions = event.isCancelled() ? com.google.common.collect.ImmutableList.of() : event.getCompletions();
+        // If the event isn't handled, we can assume that we have no completions, and so we'll ask the server
+        if (!event.isHandled()) {
+            if (!event.isCancelled()) {
+                // Paper end - async tab completion
         ParseResults parseresults = this.minecraftServer.getCommandDispatcher().a().parse(stringreader, this.player.getCommandListener());
 
         this.minecraftServer.getCommandDispatcher().a().getCompletionSuggestions(parseresults).thenAccept((suggestions) -> {
             if (((Suggestions) suggestions).isEmpty()) return; // CraftBukkit - don't send through empty suggestions - prevents [<args>] from showing for plugins with nothing more to offer
-            this.networkManager.sendPacket(new PacketPlayOutTabComplete(packetplayintabcomplete.b(), (Suggestions) suggestions)); // CraftBukkit - decompile error
-        });
+                this.networkManager.sendPacket(new PacketPlayOutTabComplete(packetplayintabcomplete.b(), (Suggestions) suggestions)); // CraftBukkit - decompile error
+            });
+            }
+        // Paper start - async tab completion
+        } else if (!completions.isEmpty()) {
+            com.mojang.brigadier.suggestion.SuggestionsBuilder suggestionsBuilder = new com.mojang.brigadier.suggestion.SuggestionsBuilder(packetplayintabcomplete.c(), stringreader.getTotalLength());
+            completions.forEach(suggestionsBuilder::suggest);
+
+            player.playerConnection.sendPacket(new PacketPlayOutTabComplete(packetplayintabcomplete.b(), suggestionsBuilder.build()));
+        }
+        // Paper end - async tab completion
+
     }
 
     public void a(PacketPlayInSetCommandBlock packetplayinsetcommandblock) {
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 74e466d1f6..0e582e4e5c 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1719,7 +1719,7 @@ public final class CraftServer implements Server {
             offers = tabCompleteChat(player, message);
         }
 
-        TabCompleteEvent tabEvent = new TabCompleteEvent(player, message, offers);
+        TabCompleteEvent tabEvent = new TabCompleteEvent(player, message, offers, message.startsWith("/") || forceCommand, pos != null ? MCUtil.toLocation(((CraftWorld) player.getWorld()).getHandle(), new BlockPosition(pos)) : null); // Paper
         getPluginManager().callEvent(tabEvent);
 
         return tabEvent.isCancelled() ? Collections.EMPTY_LIST : tabEvent.getCompletions();
diff --git a/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java b/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
index 1e3aae3b8f..95d13c146b 100644
--- a/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
+++ b/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
@@ -28,6 +28,39 @@ public class ConsoleCommandCompleter implements Completer {
     public void complete(LineReader reader, ParsedLine line, List<Candidate> candidates) {
         final CraftServer server = this.server.server;
         final String buffer = line.line();
+        // Async Tab Complete
+        com.destroystokyo.paper.event.server.AsyncTabCompleteEvent event;
+        java.util.List<String> completions = new java.util.ArrayList<>();
+        event = new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(server.getConsoleSender(), completions,
+            buffer, true, null);
+        event.callEvent();
+        completions = event.isCancelled() ? com.google.common.collect.ImmutableList.of() : event.getCompletions();
+
+        if (event.isCancelled() || event.isHandled()) {
+            // Still fire sync event with the provided completions, if someone is listening
+            if (!event.isCancelled() && TabCompleteEvent.getHandlerList().getRegisteredListeners().length > 0) {
+                List<String> finalCompletions = completions;
+                Waitable<List<String>> syncCompletions = new Waitable<List<String>>() {
+                    @Override
+                    protected List<String> evaluate() {
+                        org.bukkit.event.server.TabCompleteEvent syncEvent = new org.bukkit.event.server.TabCompleteEvent(server.getConsoleSender(), buffer, finalCompletions);
+                        return syncEvent.callEvent() ? syncEvent.getCompletions() : com.google.common.collect.ImmutableList.of();
+                    }
+                };
+                server.getServer().processQueue.add(syncCompletions);
+                try {
+                    completions = syncCompletions.get();
+                } catch (InterruptedException | ExecutionException e1) {
+                    e1.printStackTrace();
+                }
+            }
+
+            if (!completions.isEmpty()) {
+                candidates.addAll(completions.stream().map(Candidate::new).collect(java.util.stream.Collectors.toList()));
+            }
+            return;
+        }
+
         // Paper end
         Waitable<List<String>> waitable = new Waitable<List<String>>() {
             @Override
-- 
2.19.0