minecraft-src/net/minecraft/world/item/equipment/Equippable.java

package net.minecraft.world.item.equipment;

import com.mojang.serialization.Codec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import java.util.Optional;
import net.minecraft.core.Holder;
import net.minecraft.core.HolderGetter;
import net.minecraft.core.HolderSet;
import net.minecraft.core.RegistryCodecs;
import net.minecraft.core.registries.BuiltInRegistries;
import net.minecraft.core.registries.Registries;
import net.minecraft.network.RegistryFriendlyByteBuf;
import net.minecraft.network.codec.ByteBufCodecs;
import net.minecraft.network.codec.StreamCodec;
import net.minecraft.resources.ResourceKey;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.sounds.SoundEvent;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.stats.Stats;
import net.minecraft.tags.EntityTypeTags;
import net.minecraft.world.InteractionResult;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.EquipmentSlot;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.Mob;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.DyeColor;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.enchantment.EnchantmentEffectComponents;
import net.minecraft.world.item.enchantment.EnchantmentHelper;

public record Equippable(
	EquipmentSlot slot,
	Holder<SoundEvent> equipSound,
	Optional<ResourceKey<EquipmentAsset>> assetId,
	Optional<ResourceLocation> cameraOverlay,
	Optional<HolderSet<EntityType<?>>> allowedEntities,
	boolean dispensable,
	boolean swappable,
	boolean damageOnHurt,
	boolean equipOnInteract
) {
	public static final Codec<Equippable> CODEC = RecordCodecBuilder.create(
		instance -> instance.group(
				EquipmentSlot.CODEC.fieldOf("slot").forGetter(Equippable::slot),
				SoundEvent.CODEC.optionalFieldOf("equip_sound", SoundEvents.ARMOR_EQUIP_GENERIC).forGetter(Equippable::equipSound),
				ResourceKey.codec(EquipmentAssets.ROOT_ID).optionalFieldOf("asset_id").forGetter(Equippable::assetId),
				ResourceLocation.CODEC.optionalFieldOf("camera_overlay").forGetter(Equippable::cameraOverlay),
				RegistryCodecs.homogeneousList(Registries.ENTITY_TYPE).optionalFieldOf("allowed_entities").forGetter(Equippable::allowedEntities),
				Codec.BOOL.optionalFieldOf("dispensable", true).forGetter(Equippable::dispensable),
				Codec.BOOL.optionalFieldOf("swappable", true).forGetter(Equippable::swappable),
				Codec.BOOL.optionalFieldOf("damage_on_hurt", true).forGetter(Equippable::damageOnHurt),
				Codec.BOOL.optionalFieldOf("equip_on_interact", false).forGetter(Equippable::equipOnInteract)
			)
			.apply(instance, Equippable::new)
	);
	public static final StreamCodec<RegistryFriendlyByteBuf, Equippable> STREAM_CODEC = StreamCodec.composite(
		EquipmentSlot.STREAM_CODEC,
		Equippable::slot,
		SoundEvent.STREAM_CODEC,
		Equippable::equipSound,
		ResourceKey.streamCodec(EquipmentAssets.ROOT_ID).apply(ByteBufCodecs::optional),
		Equippable::assetId,
		ResourceLocation.STREAM_CODEC.apply(ByteBufCodecs::optional),
		Equippable::cameraOverlay,
		ByteBufCodecs.holderSet(Registries.ENTITY_TYPE).apply(ByteBufCodecs::optional),
		Equippable::allowedEntities,
		ByteBufCodecs.BOOL,
		Equippable::dispensable,
		ByteBufCodecs.BOOL,
		Equippable::swappable,
		ByteBufCodecs.BOOL,
		Equippable::damageOnHurt,
		ByteBufCodecs.BOOL,
		Equippable::equipOnInteract,
		Equippable::new
	);

	public static Equippable llamaSwag(DyeColor color) {
		return builder(EquipmentSlot.BODY)
			.setEquipSound(SoundEvents.LLAMA_SWAG)
			.setAsset((ResourceKey<EquipmentAsset>)EquipmentAssets.CARPETS.get(color))
			.setAllowedEntities(EntityType.LLAMA, EntityType.TRADER_LLAMA)
			.build();
	}

	public static Equippable saddle() {
		HolderGetter<EntityType<?>> holderGetter = BuiltInRegistries.acquireBootstrapRegistrationLookup(BuiltInRegistries.ENTITY_TYPE);
		return builder(EquipmentSlot.SADDLE)
			.setEquipSound(SoundEvents.HORSE_SADDLE)
			.setAsset(EquipmentAssets.SADDLE)
			.setAllowedEntities(holderGetter.getOrThrow(EntityTypeTags.CAN_EQUIP_SADDLE))
			.setEquipOnInteract(true)
			.build();
	}

	public static Equippable.Builder builder(EquipmentSlot slot) {
		return new Equippable.Builder(slot);
	}

	public InteractionResult swapWithEquipmentSlot(ItemStack stack, Player player) {
		if (player.canUseSlot(this.slot) && this.canBeEquippedBy(player.getType())) {
			ItemStack itemStack = player.getItemBySlot(this.slot);
			if ((!EnchantmentHelper.has(itemStack, EnchantmentEffectComponents.PREVENT_ARMOR_CHANGE) || player.isCreative())
				&& !ItemStack.isSameItemSameComponents(stack, itemStack)) {
				if (!player.level().isClientSide()) {
					player.awardStat(Stats.ITEM_USED.get(stack.getItem()));
				}

				if (stack.getCount() <= 1) {
					ItemStack itemStack2 = itemStack.isEmpty() ? stack : itemStack.copyAndClear();
					ItemStack itemStack3 = player.isCreative() ? stack.copy() : stack.copyAndClear();
					player.setItemSlot(this.slot, itemStack3);
					return InteractionResult.SUCCESS.heldItemTransformedTo(itemStack2);
				} else {
					ItemStack itemStack2 = itemStack.copyAndClear();
					ItemStack itemStack3 = stack.consumeAndReturn(1, player);
					player.setItemSlot(this.slot, itemStack3);
					if (!player.getInventory().add(itemStack2)) {
						player.drop(itemStack2, false);
					}

					return InteractionResult.SUCCESS.heldItemTransformedTo(stack);
				}
			} else {
				return InteractionResult.FAIL;
			}
		} else {
			return InteractionResult.PASS;
		}
	}

	public InteractionResult equipOnTarget(Player player, LivingEntity entity, ItemStack stack) {
		if (entity.isEquippableInSlot(stack, this.slot) && !entity.hasItemInSlot(this.slot) && entity.isAlive()) {
			if (!player.level().isClientSide()) {
				entity.setItemSlot(this.slot, stack.split(1));
				if (entity instanceof Mob mob) {
					mob.setGuaranteedDrop(this.slot);
				}
			}

			return InteractionResult.SUCCESS;
		} else {
			return InteractionResult.PASS;
		}
	}

	public boolean canBeEquippedBy(EntityType<?> entityType) {
		return this.allowedEntities.isEmpty() || ((HolderSet)this.allowedEntities.get()).contains(entityType.builtInRegistryHolder());
	}

	public static class Builder {
		private final EquipmentSlot slot;
		private Holder<SoundEvent> equipSound = SoundEvents.ARMOR_EQUIP_GENERIC;
		private Optional<ResourceKey<EquipmentAsset>> assetId = Optional.empty();
		private Optional<ResourceLocation> cameraOverlay = Optional.empty();
		private Optional<HolderSet<EntityType<?>>> allowedEntities = Optional.empty();
		private boolean dispensable = true;
		private boolean swappable = true;
		private boolean damageOnHurt = true;
		private boolean equipOnInteract;

		Builder(EquipmentSlot slot) {
			this.slot = slot;
		}

		public Equippable.Builder setEquipSound(Holder<SoundEvent> equipSound) {
			this.equipSound = equipSound;
			return this;
		}

		public Equippable.Builder setAsset(ResourceKey<EquipmentAsset> asset) {
			this.assetId = Optional.of(asset);
			return this;
		}

		public Equippable.Builder setCameraOverlay(ResourceLocation cameraOverlay) {
			this.cameraOverlay = Optional.of(cameraOverlay);
			return this;
		}

		public Equippable.Builder setAllowedEntities(EntityType<?>... allowedEntities) {
			return this.setAllowedEntities(HolderSet.direct(EntityType::builtInRegistryHolder, allowedEntities));
		}

		public Equippable.Builder setAllowedEntities(HolderSet<EntityType<?>> allowedEntities) {
			this.allowedEntities = Optional.of(allowedEntities);
			return this;
		}

		public Equippable.Builder setDispensable(boolean dispensable) {
			this.dispensable = dispensable;
			return this;
		}

		public Equippable.Builder setSwappable(boolean swappable) {
			this.swappable = swappable;
			return this;
		}

		public Equippable.Builder setDamageOnHurt(boolean damageOnHurt) {
			this.damageOnHurt = damageOnHurt;
			return this;
		}

		public Equippable.Builder setEquipOnInteract(boolean equipOnInteract) {
			this.equipOnInteract = equipOnInteract;
			return this;
		}

		public Equippable build() {
			return new Equippable(
				this.slot,
				this.equipSound,
				this.assetId,
				this.cameraOverlay,
				this.allowedEntities,
				this.dispensable,
				this.swappable,
				this.damageOnHurt,
				this.equipOnInteract
			);
		}
	}
}