minecraft-src/net/minecraft/world/entity/OminousItemSpawner.java

package net.minecraft.world.entity;

import net.minecraft.core.Direction;
import net.minecraft.core.particles.ParticleTypes;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.network.syncher.EntityDataAccessor;
import net.minecraft.network.syncher.EntityDataSerializers;
import net.minecraft.network.syncher.SynchedEntityData;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.sounds.SoundSource;
import net.minecraft.world.entity.item.ItemEntity;
import net.minecraft.world.entity.projectile.Projectile;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.ProjectileItem;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.gameevent.GameEvent;
import net.minecraft.world.level.material.PushReaction;
import net.minecraft.world.phys.Vec3;

public class OminousItemSpawner extends Entity {
	private static final int SPAWN_ITEM_DELAY_MIN = 60;
	private static final int SPAWN_ITEM_DELAY_MAX = 120;
	private static final String TAG_SPAWN_ITEM_AFTER_TICKS = "spawn_item_after_ticks";
	private static final String TAG_ITEM = "item";
	private static final EntityDataAccessor<ItemStack> DATA_ITEM = SynchedEntityData.defineId(OminousItemSpawner.class, EntityDataSerializers.ITEM_STACK);
	public static final int TICKS_BEFORE_ABOUT_TO_SPAWN_SOUND = 36;
	private long spawnItemAfterTicks;

	public OminousItemSpawner(EntityType<? extends OminousItemSpawner> entityType, Level level) {
		super(entityType, level);
		this.noPhysics = true;
	}

	public static OminousItemSpawner create(Level level, ItemStack item) {
		OminousItemSpawner ominousItemSpawner = new OminousItemSpawner(EntityType.OMINOUS_ITEM_SPAWNER, level);
		ominousItemSpawner.spawnItemAfterTicks = level.random.nextIntBetweenInclusive(60, 120);
		ominousItemSpawner.setItem(item);
		return ominousItemSpawner;
	}

	@Override
	public void tick() {
		super.tick();
		if (this.level().isClientSide) {
			this.tickClient();
		} else {
			this.tickServer();
		}
	}

	private void tickServer() {
		if (this.tickCount == this.spawnItemAfterTicks - 36L) {
			this.level().playSound(null, this.blockPosition(), SoundEvents.TRIAL_SPAWNER_ABOUT_TO_SPAWN_ITEM, SoundSource.NEUTRAL);
		}

		if (this.tickCount >= this.spawnItemAfterTicks) {
			this.spawnItem();
			this.kill();
		}
	}

	private void tickClient() {
		if (this.level().getGameTime() % 5L == 0L) {
			this.addParticles();
		}
	}

	private void spawnItem() {
		Level level = this.level();
		ItemStack itemStack = this.getItem();
		if (!itemStack.isEmpty()) {
			Entity entity;
			if (itemStack.getItem() instanceof ProjectileItem projectileItem) {
				Direction direction = Direction.DOWN;
				Projectile projectile = projectileItem.asProjectile(level, this.position(), itemStack, direction);
				projectile.setOwner(this);
				ProjectileItem.DispenseConfig dispenseConfig = projectileItem.createDispenseConfig();
				projectileItem.shoot(projectile, direction.getStepX(), direction.getStepY(), direction.getStepZ(), dispenseConfig.power(), dispenseConfig.uncertainty());
				dispenseConfig.overrideDispenseEvent().ifPresent(i -> level.levelEvent(i, this.blockPosition(), 0));
				entity = projectile;
			} else {
				entity = new ItemEntity(level, this.getX(), this.getY(), this.getZ(), itemStack);
			}

			level.addFreshEntity(entity);
			level.levelEvent(3021, this.blockPosition(), 1);
			level.gameEvent(entity, GameEvent.ENTITY_PLACE, this.position());
			this.setItem(ItemStack.EMPTY);
		}
	}

	@Override
	protected void defineSynchedData(SynchedEntityData.Builder builder) {
		builder.define(DATA_ITEM, ItemStack.EMPTY);
	}

	@Override
	protected void readAdditionalSaveData(CompoundTag compound) {
		ItemStack itemStack = compound.contains("item", 10)
			? (ItemStack)ItemStack.parse(this.registryAccess(), compound.getCompound("item")).orElse(ItemStack.EMPTY)
			: ItemStack.EMPTY;
		this.setItem(itemStack);
		this.spawnItemAfterTicks = compound.getLong("spawn_item_after_ticks");
	}

	@Override
	protected void addAdditionalSaveData(CompoundTag compound) {
		if (!this.getItem().isEmpty()) {
			compound.put("item", this.getItem().save(this.registryAccess()).copy());
		}

		compound.putLong("spawn_item_after_ticks", this.spawnItemAfterTicks);
	}

	@Override
	protected boolean canAddPassenger(Entity passenger) {
		return false;
	}

	@Override
	protected boolean couldAcceptPassenger() {
		return false;
	}

	@Override
	protected void addPassenger(Entity passenger) {
		throw new IllegalStateException("Should never addPassenger without checking couldAcceptPassenger()");
	}

	@Override
	public PushReaction getPistonPushReaction() {
		return PushReaction.IGNORE;
	}

	@Override
	public boolean isIgnoringBlockTriggers() {
		return true;
	}

	public void addParticles() {
		Vec3 vec3 = this.position();
		int i = this.random.nextIntBetweenInclusive(1, 3);

		for (int j = 0; j < i; j++) {
			double d = 0.4;
			Vec3 vec32 = new Vec3(
				this.getX() + 0.4 * (this.random.nextGaussian() - this.random.nextGaussian()),
				this.getY() + 0.4 * (this.random.nextGaussian() - this.random.nextGaussian()),
				this.getZ() + 0.4 * (this.random.nextGaussian() - this.random.nextGaussian())
			);
			Vec3 vec33 = vec3.vectorTo(vec32);
			this.level().addParticle(ParticleTypes.OMINOUS_SPAWNING, vec3.x(), vec3.y(), vec3.z(), vec33.x(), vec33.y(), vec33.z());
		}
	}

	public ItemStack getItem() {
		return this.getEntityData().get(DATA_ITEM);
	}

	private void setItem(ItemStack item) {
		this.getEntityData().set(DATA_ITEM, item);
	}
}