package net.minecraft.world.entity;

import com.mojang.logging.LogUtils;
import com.mojang.serialization.Codec;
import java.util.Optional;
import java.util.stream.Stream;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.core.Holder;
import net.minecraft.core.component.DataComponents;
import net.minecraft.core.registries.BuiltInRegistries;
import net.minecraft.core.registries.Registries;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.network.RegistryFriendlyByteBuf;
import net.minecraft.network.chat.Component;
import net.minecraft.network.codec.ByteBufCodecs;
import net.minecraft.network.codec.StreamCodec;
import net.minecraft.resources.DependantName;
import net.minecraft.resources.Identifier;
import net.minecraft.resources.ResourceKey;
import net.minecraft.server.MinecraftServer;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.tags.BlockTags;
import net.minecraft.tags.TagKey;
import net.minecraft.util.Mth;
import net.minecraft.util.ProblemReporter;
import net.minecraft.util.Util;
import net.minecraft.util.datafix.fixes.References;
import net.minecraft.world.Difficulty;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.flag.FeatureElement;
import net.minecraft.world.flag.FeatureFlag;
import net.minecraft.world.flag.FeatureFlagSet;
import net.minecraft.world.flag.FeatureFlags;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.component.TypedEntityData;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.LevelReader;
import net.minecraft.world.level.block.Block;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.entity.EntityTypeTest;
import net.minecraft.world.level.pathfinder.NodeEvaluator;
import net.minecraft.world.level.storage.TagValueInput;
import net.minecraft.world.level.storage.ValueInput;
import net.minecraft.world.level.storage.loot.LootTable;
import net.minecraft.world.phys.AABB;
import net.minecraft.world.phys.Vec3;
import net.minecraft.world.phys.shapes.Shapes;
import net.minecraft.world.phys.shapes.VoxelShape;
import org.jspecify.annotations.Nullable;
import org.slf4j.Logger;

public class EntityType<T extends Entity> implements EntityTypeTest<Entity, T>, FeatureElement {
	private static final Logger LOGGER = LogUtils.getLogger();
	private final Holder.Reference<EntityType<?>> builtInRegistryHolder = BuiltInRegistries.ENTITY_TYPE.createIntrusiveHolder(this);
	public static final Codec<EntityType<?>> CODEC = BuiltInRegistries.ENTITY_TYPE.byNameCodec();
	public static final StreamCodec<RegistryFriendlyByteBuf, EntityType<?>> STREAM_CODEC = ByteBufCodecs.registry(Registries.ENTITY_TYPE);
	private final EntityType.EntityFactory<T> factory;
	private final MobCategory category;
	private final TagKey<Block> immuneTo;
	private final boolean serialize;
	private final boolean summon;
	private final boolean fireImmune;
	private final boolean canSpawnFarFromPlayer;
	private final int clientTrackingRange;
	private final int updateInterval;
	private final String descriptionId;
	private @Nullable Component description;
	private final Optional<ResourceKey<LootTable>> lootTable;
	private final EntityDimensions dimensions;
	private final float spawnDimensionsScale;
	private final FeatureFlagSet requiredFeatures;
	private final boolean allowedInPeaceful;

	public static Identifier getKey(final EntityType<?> type) {
		return BuiltInRegistries.ENTITY_TYPE.getKey(type);
	}

	public EntityType(
		final EntityType.EntityFactory<T> factory,
		final MobCategory category,
		final boolean serialize,
		final boolean summon,
		final boolean fireImmune,
		final boolean canSpawnFarFromPlayer,
		final TagKey<Block> immuneTo,
		final EntityDimensions dimensions,
		final float spawnDimensionsScale,
		final int clientTrackingRange,
		final int updateInterval,
		final String descriptionId,
		final Optional<ResourceKey<LootTable>> lootTable,
		final FeatureFlagSet requiredFeatures,
		final boolean allowedInPeaceful
	) {
		this.factory = factory;
		this.category = category;
		this.canSpawnFarFromPlayer = canSpawnFarFromPlayer;
		this.serialize = serialize;
		this.summon = summon;
		this.fireImmune = fireImmune;
		this.immuneTo = immuneTo;
		this.dimensions = dimensions;
		this.spawnDimensionsScale = spawnDimensionsScale;
		this.clientTrackingRange = clientTrackingRange;
		this.updateInterval = updateInterval;
		this.descriptionId = descriptionId;
		this.lootTable = lootTable;
		this.requiredFeatures = requiredFeatures;
		this.allowedInPeaceful = allowedInPeaceful;
	}

	public @Nullable T spawn(
		final ServerLevel level,
		final @Nullable ItemStack itemStack,
		final @Nullable LivingEntity user,
		final BlockPos spawnPos,
		final EntitySpawnReason spawnReason,
		final boolean tryMoveDown,
		final boolean movedUp
	) {
		PostSpawnProcessor<T> postSpawnConfig;
		if (itemStack != null) {
			postSpawnConfig = createDefaultStackConfig(level, itemStack, user);
		} else {
			postSpawnConfig = PostSpawnProcessor.nop();
		}

		return this.spawn(level, postSpawnConfig, spawnPos, spawnReason, tryMoveDown, movedUp);
	}

	public static <T extends Entity> PostSpawnProcessor<T> createDefaultStackConfig(
		final Level level, final ItemStack itemStack, final @Nullable LivingEntity user
	) {
		return appendDefaultStackConfig(PostSpawnProcessor.nop(), level, itemStack, user);
	}

	public static <T extends Entity> PostSpawnProcessor<T> appendDefaultStackConfig(
		final PostSpawnProcessor<T> initialConfig, final Level level, final ItemStack itemStack, final @Nullable LivingEntity user
	) {
		return appendCustomEntityStackConfig(appendComponentsConfig(initialConfig, itemStack), level, itemStack, user);
	}

	public static <T extends Entity> PostSpawnProcessor<T> appendComponentsConfig(final PostSpawnProcessor<T> initialConfig, final ItemStack itemStack) {
		return initialConfig.andThen(entity -> entity.applyComponentsFromItemStack(itemStack));
	}

	public static <T extends Entity> PostSpawnProcessor<T> appendCustomEntityStackConfig(
		final PostSpawnProcessor<T> initialConfig, final Level level, final ItemStack itemStack, final @Nullable LivingEntity user
	) {
		TypedEntityData<EntityType<?>> entityData = itemStack.get(DataComponents.ENTITY_DATA);
		return entityData != null ? initialConfig.andThen(entity -> updateCustomEntityTag(level, user, entity, entityData)) : initialConfig;
	}

	public @Nullable T spawn(final ServerLevel level, final BlockPos spawnPos, final EntitySpawnReason spawnReason) {
		return this.spawn(level, null, spawnPos, spawnReason, false, false);
	}

	public @Nullable T spawn(
		final ServerLevel level,
		final @Nullable PostSpawnProcessor<T> postSpawnConfig,
		final BlockPos spawnPos,
		final EntitySpawnReason spawnReason,
		final boolean tryMoveDown,
		final boolean movedUp
	) {
		T entity = this.create(level, postSpawnConfig, spawnPos, spawnReason, tryMoveDown, movedUp);
		if (entity != null) {
			level.addFreshEntityWithPassengers(entity);
			if (entity instanceof Mob mob) {
				mob.playAmbientSound();
			}
		}

		return entity;
	}

	public @Nullable T create(
		final ServerLevel level,
		final @Nullable PostSpawnProcessor<T> postSpawnConfig,
		final BlockPos spawnPos,
		final EntitySpawnReason spawnReason,
		final boolean tryMoveDown,
		final boolean movedUp
	) {
		T entity = this.create(level, spawnReason);
		if (entity == null) {
			return null;
		}

		double yOff;
		if (tryMoveDown) {
			entity.setPos(spawnPos.getX() + 0.5, spawnPos.getY() + 1, spawnPos.getZ() + 0.5);
			yOff = getYOffset(level, spawnPos, movedUp, entity.getBoundingBox());
		} else {
			yOff = 0.0;
		}

		entity.snapTo(spawnPos.getX() + 0.5, spawnPos.getY() + yOff, spawnPos.getZ() + 0.5, Mth.wrapDegrees(level.getRandom().nextFloat() * 360.0F), 0.0F);
		if (entity instanceof Mob mob) {
			mob.yHeadRot = mob.getYRot();
			mob.yBodyRot = mob.getYRot();
			mob.finalizeSpawn(level, level.getCurrentDifficultyAt(mob.blockPosition()), spawnReason, null);
		}

		if (postSpawnConfig != null) {
			postSpawnConfig.apply(entity);
		}

		return entity;
	}

	protected static double getYOffset(final LevelReader level, final BlockPos spawnPos, final boolean movedUp, final AABB entityBox) {
		AABB aabb = new AABB(spawnPos);
		if (movedUp) {
			aabb = aabb.expandTowards(0.0, -1.0, 0.0);
		}

		Iterable<VoxelShape> shapes = level.getCollisions(null, aabb);
		return 1.0 + Shapes.collide(Direction.Axis.Y, entityBox, shapes, movedUp ? -2.0 : -1.0);
	}

	public static void updateCustomEntityTag(
		final Level level, final @Nullable LivingEntity user, final @Nullable Entity entity, final TypedEntityData<EntityType<?>> entityData
	) {
		MinecraftServer server = level.getServer();
		if (server != null && entity != null) {
			if (entity.getType() == entityData.type()) {
				if (level.isClientSide() || !entity.getType().onlyOpCanSetNbt() || user instanceof Player player && server.getPlayerList().isOp(player.nameAndId())) {
					entityData.loadInto(entity);
				}
			}
		}
	}

	public boolean canSerialize() {
		return this.serialize;
	}

	public boolean canSummon() {
		return this.summon;
	}

	public boolean fireImmune() {
		return this.fireImmune;
	}

	public boolean canSpawnFarFromPlayer() {
		return this.canSpawnFarFromPlayer;
	}

	public MobCategory getCategory() {
		return this.category;
	}

	public String getDescriptionId() {
		return this.descriptionId;
	}

	public Component getDescription() {
		if (this.description == null) {
			this.description = Component.translatable(this.getDescriptionId());
		}

		return this.description;
	}

	@Override
	public String toString() {
		return this.getDescriptionId();
	}

	public String toShortString() {
		int dot = this.getDescriptionId().lastIndexOf(46);
		return dot == -1 ? this.getDescriptionId() : this.getDescriptionId().substring(dot + 1);
	}

	public Optional<ResourceKey<LootTable>> getDefaultLootTable() {
		return this.lootTable;
	}

	public float getWidth() {
		return this.dimensions.width();
	}

	public float getHeight() {
		return this.dimensions.height();
	}

	@Override
	public FeatureFlagSet requiredFeatures() {
		return this.requiredFeatures;
	}

	public boolean canSpawn(final Level level) {
		return !this.isEnabled(level.enabledFeatures()) ? false : this.isAllowedInPeaceful() || level.getDifficulty() != Difficulty.PEACEFUL;
	}

	public @Nullable T create(final Level level, final EntitySpawnReason reason) {
		return this.create(level, new EntitySpawnRequest(reason, false));
	}

	public @Nullable T create(final Level level, final EntitySpawnRequest request) {
		return !request.ignoreChecks() && !this.canSpawn(level) ? null : this.factory.create(this, level);
	}

	public static Optional<Entity> create(final ValueInput input, final Level level, final EntitySpawnRequest request) {
		return Util.ifElse(
			by(input).map(type -> type.create(level, request)),
			entity -> entity.load(input),
			() -> LOGGER.warn("Skipping Entity with id {}", input.getStringOr("id", "[invalid]"))
		);
	}

	public static Optional<Entity> create(final EntityType<?> type, final ValueInput input, final Level level, final EntitySpawnReason reason) {
		Optional<Entity> entity = Optional.ofNullable(type.create(level, reason));
		entity.ifPresent(e -> e.load(input));
		return entity;
	}

	public AABB getSpawnAABB(final double x, final double y, final double z) {
		float halfWidth = this.spawnDimensionsScale * this.getWidth() / 2.0F;
		float height = this.spawnDimensionsScale * this.getHeight();
		return new AABB(x - halfWidth, y, z - halfWidth, x + halfWidth, y + height, z + halfWidth);
	}

	public boolean isBlockDangerous(final BlockState state) {
		if (state.is(this.immuneTo)) {
			return false;
		} else {
			return !this.fireImmune && NodeEvaluator.isBurningBlock(state)
				? true
				: state.is(Blocks.WITHER_ROSE) || state.is(Blocks.SWEET_BERRY_BUSH) || state.is(Blocks.CACTUS) || state.is(Blocks.POWDER_SNOW);
		}
	}

	public EntityDimensions getDimensions() {
		return this.dimensions;
	}

	public static Optional<EntityType<?>> by(final ValueInput input) {
		return input.read("id", CODEC);
	}

	public static @Nullable Entity loadEntityRecursive(final CompoundTag tag, final Level level, final EntitySpawnRequest request, final EntityProcessor postLoad) {
		try (ProblemReporter.ScopedCollector reporter = new ProblemReporter.ScopedCollector(LOGGER)) {
			return loadEntityRecursive(TagValueInput.create(reporter, level.registryAccess(), tag), level, request, postLoad);
		}
	}

	public static @Nullable Entity loadEntityRecursive(
		final EntityType<?> type, final CompoundTag tag, final Level level, final EntitySpawnReason reason, final EntityProcessor postLoad
	) {
		try (ProblemReporter.ScopedCollector reporter = new ProblemReporter.ScopedCollector(LOGGER)) {
			return loadEntityRecursive(type, TagValueInput.create(reporter, level.registryAccess(), tag), level, reason, postLoad);
		}
	}

	public static @Nullable Entity loadEntityRecursive(final ValueInput input, final Level level, final EntitySpawnReason reason, final EntityProcessor postLoad) {
		return loadEntityRecursive(input, level, new EntitySpawnRequest(reason, false), postLoad);
	}

	public static @Nullable Entity loadEntityRecursive(final ValueInput input, final Level level, final EntitySpawnRequest request, final EntityProcessor postLoad) {
		return loadStaticEntity(input, level, request)
			.map(postLoad::process)
			.map(entity -> loadPassengersRecursive(entity, input, level, request, postLoad))
			.orElse(null);
	}

	public static @Nullable Entity loadEntityRecursive(
		final EntityType<?> type, final ValueInput input, final Level level, final EntitySpawnReason reason, final EntityProcessor postLoad
	) {
		return loadStaticEntity(type, input, level, reason)
			.map(postLoad::process)
			.map(entity -> loadPassengersRecursive(entity, input, level, new EntitySpawnRequest(reason, false), postLoad))
			.orElse(null);
	}

	private static Entity loadPassengersRecursive(
		final Entity entity, final ValueInput input, final Level level, final EntitySpawnRequest request, final EntityProcessor postLoad
	) {
		for (ValueInput passengerTag : input.childrenListOrEmpty("Passengers")) {
			Entity passenger = loadEntityRecursive(passengerTag, level, request, postLoad);
			if (passenger != null) {
				passenger.startRiding(entity, true, false);
			}
		}

		return entity;
	}

	public static Stream<Entity> loadEntitiesRecursive(final ValueInput.ValueInputList entities, final Level level, final EntitySpawnReason reason) {
		return entities.stream().mapMulti((tag, output) -> loadEntityRecursive(tag, level, reason, entity -> {
			output.accept(entity);
			return entity;
		}));
	}

	private static Optional<Entity> loadStaticEntity(final ValueInput input, final Level level, final EntitySpawnRequest request) {
		try {
			return create(input, level, request);
		} catch (RuntimeException e) {
			LOGGER.warn("Exception loading entity: ", e);
			return Optional.empty();
		}
	}

	private static Optional<Entity> loadStaticEntity(final EntityType<?> type, final ValueInput input, final Level level, final EntitySpawnReason reason) {
		try {
			return create(type, input, level, reason);
		} catch (RuntimeException e) {
			LOGGER.warn("Exception loading entity: ", e);
			return Optional.empty();
		}
	}

	public int clientTrackingRange() {
		return this.clientTrackingRange;
	}

	public int updateInterval() {
		return this.updateInterval;
	}

	public boolean trackDeltas() {
		return this != EntityTypes.PLAYER
			&& this != EntityTypes.LLAMA_SPIT
			&& this != EntityTypes.WITHER
			&& this != EntityTypes.BAT
			&& this != EntityTypes.ITEM_FRAME
			&& this != EntityTypes.GLOW_ITEM_FRAME
			&& this != EntityTypes.LEASH_KNOT
			&& this != EntityTypes.PAINTING
			&& this != EntityTypes.END_CRYSTAL
			&& this != EntityTypes.EVOKER_FANGS;
	}

	public @Nullable T tryCast(final Entity entity) {
		return (T)(entity.getType() == this ? entity : null);
	}

	@Override
	public Class<? extends Entity> getBaseClass() {
		return Entity.class;
	}

	@Deprecated
	public Holder.Reference<EntityType<?>> builtInRegistryHolder() {
		return this.builtInRegistryHolder;
	}

	public boolean isAllowedInPeaceful() {
		return this.allowedInPeaceful;
	}

	public boolean onlyOpCanSetNbt() {
		return EntityTypes.OP_ONLY_CUSTOM_DATA.contains(this);
	}

	public static class Builder<T extends Entity> implements net.fabricmc.fabric.api.object.builder.v1.entity.FabricEntityType.Builder<T> {
		private final EntityType.EntityFactory<T> factory;
		private final MobCategory category;
		private TagKey<Block> immuneTo = BlockTags.DEFAULT_IMMUNE_TO;
		private boolean serialize = true;
		private boolean summon = true;
		private boolean fireImmune;
		private boolean canSpawnFarFromPlayer;
		private int clientTrackingRange = 5;
		private int updateInterval = 3;
		private EntityDimensions dimensions = EntityDimensions.scalable(0.6F, 1.8F);
		private float spawnDimensionsScale = 1.0F;
		private EntityAttachments.Builder attachments = EntityAttachments.builder();
		private FeatureFlagSet requiredFeatures = FeatureFlags.VANILLA_SET;
		private DependantName<EntityType<?>, Optional<ResourceKey<LootTable>>> lootTable = id -> Optional.of(
			ResourceKey.create(Registries.LOOT_TABLE, id.identifier().withPrefix("entities/"))
		);
		private final DependantName<EntityType<?>, String> descriptionId = id -> Util.makeDescriptionId("entity", id.identifier());
		private boolean allowedInPeaceful = true;

		private Builder(final EntityType.EntityFactory<T> factory, final MobCategory category) {
			this.factory = factory;
			this.category = category;
			this.canSpawnFarFromPlayer = category == MobCategory.CREATURE || category == MobCategory.MISC;
		}

		public static <T extends Entity> EntityType.Builder<T> of(final EntityType.EntityFactory<T> factory, final MobCategory category) {
			return new EntityType.Builder<>(factory, category);
		}

		public static <T extends Entity> EntityType.Builder<T> createNothing(final MobCategory category) {
			return new EntityType.Builder<>((t, l) -> null, category);
		}

		public EntityType.Builder<T> sized(final float width, final float height) {
			this.dimensions = EntityDimensions.scalable(width, height);
			return this;
		}

		public EntityType.Builder<T> spawnDimensionsScale(final float scale) {
			this.spawnDimensionsScale = scale;
			return this;
		}

		public EntityType.Builder<T> eyeHeight(final float eyeHeight) {
			this.dimensions = this.dimensions.withEyeHeight(eyeHeight);
			return this;
		}

		public EntityType.Builder<T> passengerAttachments(final float... offsetYs) {
			for (float offsetY : offsetYs) {
				this.attachments = this.attachments.attach(EntityAttachment.PASSENGER, 0.0F, offsetY, 0.0F);
			}

			return this;
		}

		public EntityType.Builder<T> passengerAttachments(final Vec3... points) {
			for (Vec3 point : points) {
				this.attachments = this.attachments.attach(EntityAttachment.PASSENGER, point);
			}

			return this;
		}

		public EntityType.Builder<T> vehicleAttachment(final Vec3 point) {
			return this.attach(EntityAttachment.VEHICLE, point);
		}

		public EntityType.Builder<T> ridingOffset(final float ridingOffset) {
			return this.attach(EntityAttachment.VEHICLE, 0.0F, -ridingOffset, 0.0F);
		}

		public EntityType.Builder<T> nameTagOffset(final float nameTagOffset) {
			return this.attach(EntityAttachment.NAME_TAG, 0.0F, nameTagOffset, 0.0F);
		}

		public EntityType.Builder<T> attach(final EntityAttachment attachment, final float x, final float y, final float z) {
			this.attachments = this.attachments.attach(attachment, x, y, z);
			return this;
		}

		public EntityType.Builder<T> attach(final EntityAttachment attachment, final Vec3 point) {
			this.attachments = this.attachments.attach(attachment, point);
			return this;
		}

		public EntityType.Builder<T> noSummon() {
			this.summon = false;
			return this;
		}

		public EntityType.Builder<T> noSave() {
			this.serialize = false;
			return this;
		}

		public EntityType.Builder<T> fireImmune() {
			this.fireImmune = true;
			return this;
		}

		public EntityType.Builder<T> immuneTo(final TagKey<Block> tag) {
			this.immuneTo = tag;
			return this;
		}

		public EntityType.Builder<T> canSpawnFarFromPlayer() {
			this.canSpawnFarFromPlayer = true;
			return this;
		}

		public EntityType.Builder<T> clientTrackingRange(final int clientChunkRange) {
			this.clientTrackingRange = clientChunkRange;
			return this;
		}

		public EntityType.Builder<T> updateInterval(final int updateInterval) {
			this.updateInterval = updateInterval;
			return this;
		}

		public EntityType.Builder<T> requiredFeatures(final FeatureFlag... flags) {
			this.requiredFeatures = FeatureFlags.REGISTRY.subset(flags);
			return this;
		}

		public EntityType.Builder<T> noLootTable() {
			this.lootTable = DependantName.fixed(Optional.empty());
			return this;
		}

		public EntityType.Builder<T> notInPeaceful() {
			this.allowedInPeaceful = false;
			return this;
		}

		public EntityType<T> build(final ResourceKey<EntityType<?>> name) {
			if (this.serialize) {
				Util.fetchChoiceType(References.ENTITY_TREE, name.identifier().toString());
			}

			return new EntityType<>(
				this.factory,
				this.category,
				this.serialize,
				this.summon,
				this.fireImmune,
				this.canSpawnFarFromPlayer,
				this.immuneTo,
				this.dimensions.withAttachments(this.attachments),
				this.spawnDimensionsScale,
				this.clientTrackingRange,
				this.updateInterval,
				this.descriptionId.get(name),
				this.lootTable.get(name),
				this.requiredFeatures,
				this.allowedInPeaceful
			);
		}
	}

	@FunctionalInterface
	public interface EntityFactory<T extends Entity> {
		@Nullable T create(final EntityType<T> entityType, final Level level);
	}
}