package net.minecraft.network.protocol.game;

import net.minecraft.commands.arguments.EntityAnchorArgument;
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.world.entity.Entity;
import net.minecraft.world.level.Level;
import net.minecraft.world.phys.Vec3;
import org.jspecify.annotations.Nullable;

public class ClientboundPlayerLookAtPacket implements Packet<ClientGamePacketListener> {
	public static final StreamCodec<FriendlyByteBuf, ClientboundPlayerLookAtPacket> STREAM_CODEC = Packet.codec(
		ClientboundPlayerLookAtPacket::write, ClientboundPlayerLookAtPacket::new
	);
	private final double x;
	private final double y;
	private final double z;
	private final int entity;
	private final EntityAnchorArgument.Anchor fromAnchor;
	private final EntityAnchorArgument.Anchor toAnchor;
	private final boolean atEntity;

	public ClientboundPlayerLookAtPacket(final EntityAnchorArgument.Anchor fromAnchor, final double x, final double y, final double z) {
		this.fromAnchor = fromAnchor;
		this.x = x;
		this.y = y;
		this.z = z;
		this.entity = 0;
		this.atEntity = false;
		this.toAnchor = null;
	}

	public ClientboundPlayerLookAtPacket(final EntityAnchorArgument.Anchor fromAnchor, final Entity entity, final EntityAnchorArgument.Anchor toAnchor) {
		this.fromAnchor = fromAnchor;
		this.entity = entity.getId();
		this.toAnchor = toAnchor;
		Vec3 pos = toAnchor.apply(entity);
		this.x = pos.x;
		this.y = pos.y;
		this.z = pos.z;
		this.atEntity = true;
	}

	private ClientboundPlayerLookAtPacket(final FriendlyByteBuf input) {
		this.fromAnchor = input.readEnum(EntityAnchorArgument.Anchor.class);
		this.x = input.readDouble();
		this.y = input.readDouble();
		this.z = input.readDouble();
		this.atEntity = input.readBoolean();
		if (this.atEntity) {
			this.entity = input.readVarInt();
			this.toAnchor = input.readEnum(EntityAnchorArgument.Anchor.class);
		} else {
			this.entity = 0;
			this.toAnchor = null;
		}
	}

	private void write(final FriendlyByteBuf output) {
		output.writeEnum(this.fromAnchor);
		output.writeDouble(this.x);
		output.writeDouble(this.y);
		output.writeDouble(this.z);
		output.writeBoolean(this.atEntity);
		if (this.atEntity) {
			output.writeVarInt(this.entity);
			output.writeEnum(this.toAnchor);
		}
	}

	@Override
	public PacketType<ClientboundPlayerLookAtPacket> type() {
		return GamePacketTypes.CLIENTBOUND_PLAYER_LOOK_AT;
	}

	public void handle(final ClientGamePacketListener listener) {
		listener.handleLookAt(this);
	}

	public EntityAnchorArgument.Anchor getFromAnchor() {
		return this.fromAnchor;
	}

	@Nullable
	public Vec3 getPosition(final Level level) {
		if (this.atEntity) {
			Entity entity = level.getEntity(this.entity);
			return entity == null ? new Vec3(this.x, this.y, this.z) : this.toAnchor.apply(entity);
		} else {
			return new Vec3(this.x, this.y, this.z);
		}
	}
}