From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
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

Co-authored-by: Aikar <aikar@aikar.co>

diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index fb2918f3f99bae7b549412712adeeb55a45c9e9b..c8193e4fc77612f4535f360777dbe93f75b5be4e 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -776,12 +776,16 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
 
     }
 
+    // Paper start
+    private static final java.util.concurrent.ExecutorService TAB_COMPLETE_EXECUTOR = java.util.concurrent.Executors.newFixedThreadPool(4,
+        new com.google.common.util.concurrent.ThreadFactoryBuilder().setDaemon(true).setNameFormat("Async Tab Complete Thread - #%d").setUncaughtExceptionHandler(new net.minecraft.DefaultUncaughtExceptionHandlerWithName(net.minecraft.server.MinecraftServer.LOGGER)).build());
+    // Paper end
     @Override
     public void handleCustomCommandSuggestions(ServerboundCommandSuggestionPacket packet) {
-        PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel());
+        // PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel()); // Paper - run this async
         // CraftBukkit start
         if (this.chatSpamTickCount.addAndGet(1) > 500 && !this.server.getPlayerList().isOp(this.player.getGameProfile())) {
-            this.disconnect(Component.translatable("disconnect.spam"));
+            server.scheduleOnMain(() -> this.disconnect(Component.translatable("disconnect.spam", new Object[0]))); // Paper
             return;
         }
         // Paper start
@@ -792,18 +796,45 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
         }
         // Paper end
         // CraftBukkit end
+        // Paper start - async tab completion
+        TAB_COMPLETE_EXECUTOR.execute(() -> {
         StringReader stringreader = new StringReader(packet.getCommand());
 
         if (stringreader.canRead() && stringreader.peek() == '/') {
             stringreader.skip();
         }
-
-        ParseResults<CommandSourceStack> parseresults = this.server.getCommands().getDispatcher().parse(stringreader, this.player.createCommandSourceStack());
-
-        this.server.getCommands().getDispatcher().getCompletionSuggestions(parseresults).thenAccept((suggestions) -> {
-            if (suggestions.isEmpty()) return; // CraftBukkit - don't send through empty suggestions - prevents [<args>] from showing for plugins with nothing more to offer
-            this.connection.send(new ClientboundCommandSuggestionsPacket(packet.getId(), suggestions));
+            final String command = packet.getCommand();
+            final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent event = new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(this.getCraftPlayer(), command, true, null);
+            event.callEvent();
+            final java.util.List<com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion> completions = event.isCancelled() ? com.google.common.collect.ImmutableList.of() : event.completions();
+            // 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()) {
+
+                    this.server.scheduleOnMain(() -> { // This needs to be on main
+                        ParseResults<CommandSourceStack> parseresults = this.server.getCommands().getDispatcher().parse(stringreader, this.player.createCommandSourceStack());
+
+                        this.server.getCommands().getDispatcher().getCompletionSuggestions(parseresults).thenAccept((suggestions) -> {
+                            if (suggestions.isEmpty()) return; // CraftBukkit - don't send through empty suggestions - prevents [<args>] from showing for plugins with nothing more to offer
+                            this.connection.send(new ClientboundCommandSuggestionsPacket(packet.getId(), suggestions));
+                        });
+                    });
+                }
+            } else if (!completions.isEmpty()) {
+                final com.mojang.brigadier.suggestion.SuggestionsBuilder builder0 = new com.mojang.brigadier.suggestion.SuggestionsBuilder(command, stringreader.getTotalLength());
+                final com.mojang.brigadier.suggestion.SuggestionsBuilder builder = builder0.createOffset(builder0.getInput().lastIndexOf(' ') + 1);
+                completions.forEach(completion -> {
+                    final Integer intSuggestion = com.google.common.primitives.Ints.tryParse(completion.suggestion());
+                    if (intSuggestion != null) {
+                        builder.suggest(intSuggestion, PaperAdventure.asVanilla(completion.tooltip()));
+                    } else {
+                        builder.suggest(completion.suggestion(), PaperAdventure.asVanilla(completion.tooltip()));
+                    }
+                });
+                player.connection.send(new ClientboundCommandSuggestionsPacket(packet.getId(), builder.buildFuture().join()));
+            }
         });
+        // Paper end - async tab completion
     }
 
     @Override
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index bc8a2d9a4388887c8e49dd9e5ceebd0ca3b0e893..06a962ac9644df033b95f3bed3ee96a8fc00edb0 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -2113,7 +2113,7 @@ public final class CraftServer implements Server {
             offers = this.tabCompleteChat(player, message);
         }
 
-        TabCompleteEvent tabEvent = new TabCompleteEvent(player, message, offers);
+        TabCompleteEvent tabEvent = new TabCompleteEvent(player, message, offers, message.startsWith("/") || forceCommand, pos != null ? io.papermc.paper.util.MCUtil.toLocation(((CraftWorld) player.getWorld()).getHandle(), new BlockPos(pos)) : null); // Paper
         this.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 b996fde481cebbbcce80a6c267591136db7cc0bc..14cd8ae69d9b25dc5edad4ff96ff4a9acb1f22cb 100644
--- a/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
+++ b/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
@@ -28,6 +28,61 @@ 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
+        final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent event =
+            new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(server.getConsoleSender(), buffer, true, null);
+        event.callEvent();
+        final List<com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion> completions = event.isCancelled() ? com.google.common.collect.ImmutableList.of() : event.completions();
+
+        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<com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion> finalCompletions = new java.util.ArrayList<>(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.stream()
+                                .map(com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion::suggestion)
+                                .collect(java.util.stream.Collectors.toList()));
+                        return syncEvent.callEvent() ? syncEvent.getCompletions() : com.google.common.collect.ImmutableList.of();
+                    }
+                };
+                server.getServer().processQueue.add(syncCompletions);
+                try {
+                    final List<String> legacyCompletions = syncCompletions.get();
+                    completions.removeIf(it -> !legacyCompletions.contains(it.suggestion())); // remove any suggestions that were removed
+                    // add any new suggestions
+                    for (final String completion : legacyCompletions) {
+                        if (notNewSuggestion(completions, completion)) {
+                            continue;
+                        }
+                        completions.add(com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion.completion(completion));
+                    }
+                } catch (InterruptedException | ExecutionException e1) {
+                    e1.printStackTrace();
+                }
+            }
+
+            if (!completions.isEmpty()) {
+                for (final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion completion : completions) {
+                    if (completion.suggestion().isEmpty()) {
+                        continue;
+                    }
+                    candidates.add(new Candidate(
+                        completion.suggestion(),
+                        completion.suggestion(),
+                        null,
+                        io.papermc.paper.adventure.PaperAdventure.PLAIN.serializeOr(completion.tooltip(), null),
+                        null,
+                        null,
+                        false
+                    ));
+                }
+            }
+            return;
+        }
+
         // Paper end
         Waitable<List<String>> waitable = new Waitable<List<String>>() {
             @Override
@@ -73,4 +128,15 @@ public class ConsoleCommandCompleter implements Completer {
             Thread.currentThread().interrupt();
         }
     }
+
+    // Paper start
+    private boolean notNewSuggestion(final List<com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion> completions, final String completion) {
+        for (final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion it : completions) {
+            if (it.suggestion().equals(completion)) {
+                return true;
+            }
+        }
+        return false;
+    }
+    // Paper end
 }
