Code/net/minecraft/network/protocol/game/ServerboundInteractPacket.java

package net.minecraft.network.protocol.game;

import java.util.function.Function;
import javax.annotation.Nullable;
import net.minecraft.network.FriendlyByteBuf;
import net.minecraft.network.codec.StreamCodec;
import net.minecraft.network.protocol.Packet;
import net.minecraft.network.protocol.PacketType;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.world.InteractionHand;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.phys.Vec3;

public class ServerboundInteractPacket implements Packet<ServerGamePacketListener> {
    public static final StreamCodec<FriendlyByteBuf, ServerboundInteractPacket> STREAM_CODEC = Packet.codec(
        ServerboundInteractPacket::write, ServerboundInteractPacket::new
    );
    private final int entityId;
    private final ServerboundInteractPacket.Action action;
    private final boolean usingSecondaryAction;
    static final ServerboundInteractPacket.Action ATTACK_ACTION = new ServerboundInteractPacket.Action() {
        @Override
        public ServerboundInteractPacket.ActionType getType() {
            return ServerboundInteractPacket.ActionType.ATTACK;
        }

        @Override
        public void dispatch(ServerboundInteractPacket.Handler p_179624_) {
            p_179624_.onAttack();
        }

        @Override
        public void write(FriendlyByteBuf p_179622_) {
        }
    };

    private ServerboundInteractPacket(int p_179598_, boolean p_179599_, ServerboundInteractPacket.Action p_179600_) {
        this.entityId = p_179598_;
        this.action = p_179600_;
        this.usingSecondaryAction = p_179599_;
    }

    public static ServerboundInteractPacket createAttackPacket(Entity p_179606_, boolean p_179607_) {
        return new ServerboundInteractPacket(p_179606_.getId(), p_179607_, ATTACK_ACTION);
    }

    public static ServerboundInteractPacket createInteractionPacket(Entity p_179609_, boolean p_179610_, InteractionHand p_179611_) {
        return new ServerboundInteractPacket(p_179609_.getId(), p_179610_, new ServerboundInteractPacket.InteractionAction(p_179611_));
    }

    public static ServerboundInteractPacket createInteractionPacket(Entity p_179613_, boolean p_179614_, InteractionHand p_179615_, Vec3 p_179616_) {
        return new ServerboundInteractPacket(p_179613_.getId(), p_179614_, new ServerboundInteractPacket.InteractionAtLocationAction(p_179615_, p_179616_));
    }

    private ServerboundInteractPacket(FriendlyByteBuf p_179602_) {
        this.entityId = p_179602_.readVarInt();
        ServerboundInteractPacket.ActionType serverboundinteractpacket$actiontype = p_179602_.readEnum(ServerboundInteractPacket.ActionType.class);
        this.action = serverboundinteractpacket$actiontype.reader.apply(p_179602_);
        this.usingSecondaryAction = p_179602_.readBoolean();
    }

    private void write(FriendlyByteBuf p_134058_) {
        p_134058_.writeVarInt(this.entityId);
        p_134058_.writeEnum(this.action.getType());
        this.action.write(p_134058_);
        p_134058_.writeBoolean(this.usingSecondaryAction);
    }

    @Override
    public PacketType<ServerboundInteractPacket> type() {
        return GamePacketTypes.SERVERBOUND_INTERACT;
    }

    public void handle(ServerGamePacketListener p_134055_) {
        p_134055_.handleInteract(this);
    }

    @Nullable
    public Entity getTarget(ServerLevel p_179604_) {
        return p_179604_.getEntityOrPart(this.entityId);
    }

    public boolean isUsingSecondaryAction() {
        return this.usingSecondaryAction;
    }

    public void dispatch(ServerboundInteractPacket.Handler p_179618_) {
        this.action.dispatch(p_179618_);
    }

    interface Action {
        ServerboundInteractPacket.ActionType getType();

        void dispatch(ServerboundInteractPacket.Handler p_179626_);

        void write(FriendlyByteBuf p_179625_);
    }

    static enum ActionType {
        INTERACT(ServerboundInteractPacket.InteractionAction::new),
        ATTACK(p_179639_ -> ServerboundInteractPacket.ATTACK_ACTION),
        INTERACT_AT(ServerboundInteractPacket.InteractionAtLocationAction::new);

        final Function<FriendlyByteBuf, ServerboundInteractPacket.Action> reader;

        private ActionType(final Function<FriendlyByteBuf, ServerboundInteractPacket.Action> p_179636_) {
            this.reader = p_179636_;
        }
    }

    public interface Handler {
        void onInteraction(InteractionHand p_179643_);

        void onInteraction(InteractionHand p_179644_, Vec3 p_179645_);

        void onAttack();
    }

    static class InteractionAction implements ServerboundInteractPacket.Action {
        private final InteractionHand hand;

        InteractionAction(InteractionHand p_179648_) {
            this.hand = p_179648_;
        }

        private InteractionAction(FriendlyByteBuf p_179650_) {
            this.hand = p_179650_.readEnum(InteractionHand.class);
        }

        @Override
        public ServerboundInteractPacket.ActionType getType() {
            return ServerboundInteractPacket.ActionType.INTERACT;
        }

        @Override
        public void dispatch(ServerboundInteractPacket.Handler p_179655_) {
            p_179655_.onInteraction(this.hand);
        }

        @Override
        public void write(FriendlyByteBuf p_179653_) {
            p_179653_.writeEnum(this.hand);
        }
    }

    static class InteractionAtLocationAction implements ServerboundInteractPacket.Action {
        private final InteractionHand hand;
        private final Vec3 location;

        InteractionAtLocationAction(InteractionHand p_179659_, Vec3 p_179660_) {
            this.hand = p_179659_;
            this.location = p_179660_;
        }

        private InteractionAtLocationAction(FriendlyByteBuf p_179662_) {
            this.location = new Vec3(p_179662_.readFloat(), p_179662_.readFloat(), p_179662_.readFloat());
            this.hand = p_179662_.readEnum(InteractionHand.class);
        }

        @Override
        public ServerboundInteractPacket.ActionType getType() {
            return ServerboundInteractPacket.ActionType.INTERACT_AT;
        }

        @Override
        public void dispatch(ServerboundInteractPacket.Handler p_179667_) {
            p_179667_.onInteraction(this.hand, this.location);
        }

        @Override
        public void write(FriendlyByteBuf p_179665_) {
            p_179665_.writeFloat((float)this.location.x);
            p_179665_.writeFloat((float)this.location.y);
            p_179665_.writeFloat((float)this.location.z);
            p_179665_.writeEnum(this.hand);
        }
    }
}