Stacc mixin

StaccMixin.java

package net.devtech.stacc.mixin;

import io.netty.buffer.ByteBuf;
import org.spongepowered.asm.mixin.Final;
import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.Mutable;
import org.spongepowered.asm.mixin.Overwrite;
import org.spongepowered.asm.mixin.Shadow;
import org.spongepowered.asm.mixin.Unique;
import org.spongepowered.asm.mixin.injection.At;
import org.spongepowered.asm.mixin.injection.Inject;
import org.spongepowered.asm.mixin.injection.ModifyArg;
import org.spongepowered.asm.mixin.injection.Redirect;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;

import net.minecraft.inventory.Inventory;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.util.PacketByteBuf;

/**
 * by HalfOf2
 *
 * this code is licenced under CC0
 * https://creativecommons.org/publicdomain/zero/1.0/legalcode
 */
@Mixin (PacketByteBuf.class)
public abstract class StaccMixin {
	@Unique private static final int VAL = 512;

	@Shadow public abstract int readInt();

	@Redirect (method = "writeItemStack",
	           at = @At (value = "INVOKE",
	                     target = "Lnet/minecraft/util/PacketByteBuf;writeByte(I)Lio/netty/buffer/ByteBuf;"))
	private ByteBuf write(PacketByteBuf buf, int i) {
		return buf.writeInt(i);
	}

	@Redirect (method = "readItemStack",
	           at = @At (value = "INVOKE",
	                     target = "Lnet/minecraft/util/PacketByteBuf;readByte()B"))
	private byte read(PacketByteBuf buf) {
		return 0; // no-op moved to #doThing
	}

	@ModifyArg(method = "readItemStack", at = @At(value = "INVOKE", target = "Lnet/minecraft/item/ItemStack;<init>(Lnet/minecraft/item/ItemConvertible;I)V"), index = 1)
	private int doThing(int amount) {
		return this.readInt();
	}

	@Mixin(ItemStack.class)
	private static class ItemStackMixin {
		@Shadow private int count;

		@Inject(at = @At("TAIL"), method = "<init>(Lnet/minecraft/nbt/CompoundTag;)V")
		void onDeserialization(CompoundTag tag, CallbackInfo callbackInformation) {
			if (tag.contains("countInteger")) {
				this.count = tag.getInt("countInteger");
			}
		}

		@Inject(at = @At("HEAD"), method = "toTag(Lnet/minecraft/nbt/CompoundTag;)Lnet/minecraft/nbt/CompoundTag;")
		void onSerialization(CompoundTag tag, CallbackInfoReturnable<CompoundTag> callbackInformationReturnable) {
			if (this.count > Byte.MAX_VALUE) {
				tag.putInt("countInteger", this.count);
				// allow this to be cross compatible with vanilla
				this.count = 64;
			}
		}
	}


	@Mixin(Inventory.class)
	public interface InventoryMixin {
		/**
		 * @author HalfOf2
		 * @reason increase max stack size
		 */
		@Overwrite
		default int getInvMaxStackAmount() {
			return VAL;
		}
	}

	@Mixin(Item.class)
	private static class ItemMixin {
		@Mutable @Shadow @Final private int maxCount;

		@Inject (method = "<init>", at = @At("TAIL"))
		private void init(Item.Settings settings, CallbackInfo ci) {
			this.maxCount = VAL;
		}
	}
}