From fd9dab8aa12ff578a876840bb42acb30f29edf2c Mon Sep 17 00:00:00 2001
From: KennyTV <jahnke.nassim@gmail.com>
Date: Wed, 26 May 2021 21:36:20 +0200
Subject: [PATCH] Replace inventory ack by using 1.17 ping packets

---
 .../Protocol1_17To1_16_4.java                 |  5 ++-
 .../packets/InventoryPackets.java             | 32 +++++++++++++++--
 .../storage/InventoryAcknowledgements.java    | 34 +++++++++++++++++++
 3 files changed, 66 insertions(+), 5 deletions(-)
 create mode 100644 common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/storage/InventoryAcknowledgements.java

diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/Protocol1_17To1_16_4.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/Protocol1_17To1_16_4.java
index 8413a0d16..aa0db4a53 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/Protocol1_17To1_16_4.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/Protocol1_17To1_16_4.java
@@ -33,6 +33,7 @@ import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.metadata.Metadat
 import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.packets.EntityPackets;
 import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.packets.InventoryPackets;
 import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.packets.WorldPackets;
+import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.storage.InventoryAcknowledgements;
 import com.viaversion.viaversion.rewriter.EntityRewriter;
 import com.viaversion.viaversion.rewriter.RegistryType;
 import com.viaversion.viaversion.rewriter.SoundRewriter;
@@ -204,9 +205,6 @@ public class Protocol1_17To1_16_4 extends AbstractProtocol<ClientboundPackets1_1
                 });
             }
         });
-
-        // Ping
-        cancelServerbound(ServerboundPackets1_17.PONG);
     }
 
     @Override
@@ -240,6 +238,7 @@ public class Protocol1_17To1_16_4 extends AbstractProtocol<ClientboundPackets1_1
     @Override
     public void init(UserConnection user) {
         user.addEntityTracker(this.getClass(), new EntityTrackerBase(user, Entity1_17Types.PLAYER));
+        user.put(new InventoryAcknowledgements());
     }
 
     @Override
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/packets/InventoryPackets.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/packets/InventoryPackets.java
index 9cd3b583d..e7cfe7360 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/packets/InventoryPackets.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/packets/InventoryPackets.java
@@ -24,8 +24,10 @@ import com.viaversion.viaversion.api.type.Type;
 import com.viaversion.viaversion.protocols.protocol1_16_2to1_16_1.ClientboundPackets1_16_2;
 import com.viaversion.viaversion.protocols.protocol1_16_2to1_16_1.ServerboundPackets1_16_2;
 import com.viaversion.viaversion.protocols.protocol1_16to1_15_2.data.RecipeRewriter1_16;
+import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.ClientboundPackets1_17;
 import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.Protocol1_17To1_16_4;
 import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.ServerboundPackets1_17;
+import com.viaversion.viaversion.protocols.protocol1_17to1_16_4.storage.InventoryAcknowledgements;
 import com.viaversion.viaversion.rewriter.ItemRewriter;
 
 public class InventoryPackets {
@@ -96,9 +98,35 @@ public class InventoryPackets {
                     short confirmationId = wrapper.read(Type.SHORT);
                     boolean accepted = wrapper.read(Type.BOOLEAN);
                     if (!accepted) {
+                        // Use the new ping packet to replace the removed acknowledgement, extra bit for fast dismissal
+                        // Hope the client actually answers it /shrug
+                        int id = (1 << 30) | (inventoryId << 16) | confirmationId;
+                        wrapper.user().get(InventoryAcknowledgements.class).addId(id);
+
+                        PacketWrapper pingPacket = wrapper.create(ClientboundPackets1_17.PING);
+                        pingPacket.write(Type.INT, id);
+                        pingPacket.send(Protocol1_17To1_16_4.class, true, true);
+                    }
+
+                    wrapper.cancel();
+                });
+            }
+        });
+
+        // New pong packet
+        protocol.registerServerbound(ServerboundPackets1_17.PONG, null, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                handler(wrapper -> {
+                    int id = wrapper.read(Type.INT);
+                    // Check extra bit for fast dismissal
+                    if ((id & (1 << 30)) != 0 && wrapper.user().get(InventoryAcknowledgements.class).removeId(id)) {
+                        // Decode inventory acknowledgement
+                        int inventoryId = (id >> 16) & 0xFF;
+                        int confirmationId = id & 0xFFFF;
                         PacketWrapper packet = wrapper.create(ServerboundPackets1_16_2.WINDOW_CONFIRMATION);
-                        packet.write(Type.UNSIGNED_BYTE, inventoryId);
-                        packet.write(Type.SHORT, confirmationId);
+                        packet.write(Type.UNSIGNED_BYTE, (short) inventoryId);
+                        packet.write(Type.SHORT, (short) confirmationId);
                         packet.write(Type.BYTE, (byte) 1); // Accept
                         packet.sendToServer(Protocol1_17To1_16_4.class, true, true);
                     }
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/storage/InventoryAcknowledgements.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/storage/InventoryAcknowledgements.java
new file mode 100644
index 000000000..17b858a62
--- /dev/null
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_17to1_16_4/storage/InventoryAcknowledgements.java
@@ -0,0 +1,34 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2021 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.viaversion.protocols.protocol1_17to1_16_4.storage;
+
+import com.viaversion.viaversion.api.connection.StorableObject;
+import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
+import it.unimi.dsi.fastutil.ints.IntSet;
+
+public final class InventoryAcknowledgements implements StorableObject {
+    private final IntSet ids = new IntOpenHashSet();
+
+    public void addId(int id) {
+        ids.add(id);
+    }
+
+    public boolean removeId(int id) {
+        return ids.remove(id);
+    }
+}