Geyser/core/src/main/java/org/geysermc/geyser/entity/type/LivingEntity.java

/*
 * Copyright (c) 2019-2022 GeyserMC. http://geysermc.org
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @author GeyserMC
 * @link https://github.com/GeyserMC/Geyser
 */

package org.geysermc.geyser.entity.type;

import com.github.steveice10.mc.protocol.data.game.entity.attribute.Attribute;
import com.github.steveice10.mc.protocol.data.game.entity.attribute.AttributeType;
import com.github.steveice10.mc.protocol.data.game.entity.metadata.EntityMetadata;
import com.github.steveice10.mc.protocol.data.game.entity.metadata.Pose;
import com.github.steveice10.mc.protocol.data.game.entity.metadata.Position;
import com.github.steveice10.mc.protocol.data.game.entity.metadata.type.ByteEntityMetadata;
import com.github.steveice10.mc.protocol.data.game.entity.metadata.type.FloatEntityMetadata;
import com.github.steveice10.mc.protocol.data.game.entity.metadata.type.IntEntityMetadata;
import com.github.steveice10.mc.protocol.data.game.entity.player.Hand;
import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
import com.github.steveice10.opennbt.tag.builtin.StringTag;
import com.nukkitx.math.vector.Vector3f;
import com.nukkitx.math.vector.Vector3i;
import com.nukkitx.protocol.bedrock.data.AttributeData;
import com.nukkitx.protocol.bedrock.data.entity.EntityData;
import com.nukkitx.protocol.bedrock.data.entity.EntityFlag;
import com.nukkitx.protocol.bedrock.data.inventory.ContainerId;
import com.nukkitx.protocol.bedrock.data.inventory.ItemData;
import com.nukkitx.protocol.bedrock.packet.MobArmorEquipmentPacket;
import com.nukkitx.protocol.bedrock.packet.MobEquipmentPacket;
import com.nukkitx.protocol.bedrock.packet.UpdateAttributesPacket;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.Setter;
import org.geysermc.geyser.entity.EntityDefinition;
import org.geysermc.geyser.entity.attribute.GeyserAttributeType;
import org.geysermc.geyser.inventory.GeyserItemStack;
import org.geysermc.geyser.session.GeyserSession;
import org.geysermc.geyser.registry.type.ItemMapping;
import org.geysermc.geyser.util.AttributeUtils;
import org.geysermc.geyser.util.ChunkUtils;
import org.geysermc.geyser.util.InteractionResult;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.UUID;

@Getter
@Setter
public class LivingEntity extends Entity {

    protected ItemData helmet = ItemData.AIR;
    protected ItemData chestplate = ItemData.AIR;
    protected ItemData leggings = ItemData.AIR;
    protected ItemData boots = ItemData.AIR;
    protected ItemData hand = ItemData.AIR;
    protected ItemData offHand = ItemData.AIR;

    @Getter(value = AccessLevel.NONE)
    protected float health = 1f; // The default value in Java Edition before any entity metadata is sent
    @Getter(value = AccessLevel.NONE)
    protected float maxHealth = 20f; // The value Java Edition defaults to if no attribute is given

    /**
     * A convenience variable for if the entity has reached the maximum frozen ticks and should be shaking
     */
    private boolean isMaxFrozenState = false;

    public LivingEntity(GeyserSession session, int entityId, long geyserId, UUID uuid, EntityDefinition<?> definition, Vector3f position, Vector3f motion, float yaw, float pitch, float headYaw) {
        super(session, entityId, geyserId, uuid, definition, position, motion, yaw, pitch, headYaw);
    }

    @Override
    protected void initializeMetadata() {
        super.initializeMetadata();
        // Matches Bedrock behavior; is always set to this
        dirtyMetadata.put(EntityData.HEALTH, 1);
    }

    public void setLivingEntityFlags(ByteEntityMetadata entityMetadata) {
        byte xd = entityMetadata.getPrimitiveValue();

        boolean isUsingItem = (xd & 0x01) == 0x01;
        boolean isUsingOffhand = (xd & 0x02) == 0x02;

        ItemMapping shield = session.getItemMappings().getStoredItems().shield();
        boolean isUsingShield = hasShield(isUsingOffhand, shield);

        setFlag(EntityFlag.USING_ITEM, isUsingItem && !isUsingShield);
        // Override the blocking
        setFlag(EntityFlag.BLOCKING, isUsingItem && isUsingShield);

        // Riptide spin attack
        setFlag(EntityFlag.DAMAGE_NEARBY_MOBS, (xd & 0x04) == 0x04);
    }

    public void setHealth(FloatEntityMetadata entityMetadata) {
        this.health = entityMetadata.getPrimitiveValue();

        AttributeData healthData = createHealthAttribute();
        UpdateAttributesPacket attributesPacket = new UpdateAttributesPacket();
        attributesPacket.setRuntimeEntityId(geyserId);
        attributesPacket.setAttributes(Collections.singletonList(healthData));
        session.sendUpstreamPacket(attributesPacket);
    }

    public Vector3i setBedPosition(EntityMetadata<Optional<Position>, ?> entityMetadata) {
        Optional<Position> optionalPos = entityMetadata.getValue();
        if (optionalPos.isPresent()) {
            Position bedPosition = optionalPos.get();
            Vector3i vector = Vector3i.from(bedPosition.getX(), bedPosition.getY(), bedPosition.getZ());
            dirtyMetadata.put(EntityData.BED_POSITION, vector);
            int bed = session.getGeyser().getWorldManager().getBlockAt(session, bedPosition);
            // Bed has to be updated, or else player is floating in the air
            ChunkUtils.updateBlock(session, bed, bedPosition);
            // Indicate that the player should enter the sleep cycle
            // Has to be a byte or it does not work
            // (Bed position is what actually triggers sleep - "pose" is only optional)
            dirtyMetadata.put(EntityData.PLAYER_FLAGS, (byte) 2);
            return vector;
        } else {
            // Player is no longer sleeping
            dirtyMetadata.put(EntityData.PLAYER_FLAGS, (byte) 0);
            return null;
        }
    }

    protected boolean hasShield(boolean offhand, ItemMapping shieldMapping) {
        if (offhand) {
            return offHand.getId() == shieldMapping.getBedrockId();
        } else {
            return hand.getId() == shieldMapping.getBedrockId();
        }
    }

    @Override
    protected boolean isShaking() {
        return isMaxFrozenState;
    }

    @Override
    protected void setDimensions(Pose pose) {
        if (pose == Pose.SLEEPING) {
            setBoundingBoxWidth(0.2f);
            setBoundingBoxHeight(0.2f);
        } else {
            super.setDimensions(pose);
        }
    }

    @Override
    public float setFreezing(IntEntityMetadata entityMetadata) {
        float freezingPercentage = super.setFreezing(entityMetadata);
        this.isMaxFrozenState = freezingPercentage >= 1.0f;
        setFlag(EntityFlag.SHAKING, isShaking());
        return freezingPercentage;
    }

    /**
     * @return a Bedrock health attribute constructed from the data sent from the server
     */
    protected AttributeData createHealthAttribute() {
        // Default health needs to be specified as the max health in order for maximum hearts to show correctly on mounted entities
        // Round health value up, so that Bedrock doesn't consider the entity to be dead when health is between 0 and 1
        return new AttributeData(GeyserAttributeType.HEALTH.getBedrockIdentifier(), 0f, this.maxHealth, (float) Math.ceil(this.health), this.maxHealth);
    }

    @Override
    public boolean isAlive() {
        return this.valid && health > 0f;
    }

    @Override
    public InteractionResult interact(Hand hand) {
        GeyserItemStack itemStack = session.getPlayerInventory().getItemInHand(hand);
        if (itemStack.getJavaId() == session.getItemMappings().getStoredItems().nameTag()) {
            InteractionResult result = checkInteractWithNameTag(itemStack);
            if (result.consumesAction()) {
                return result;
            }
        }

        return super.interact(hand);
    }

    /**
     * Checks to see if a nametag interaction would go through.
     */
    protected final InteractionResult checkInteractWithNameTag(GeyserItemStack itemStack) {
        CompoundTag nbt = itemStack.getNbt();
        if (nbt != null && nbt.get("display") instanceof CompoundTag displayTag && displayTag.get("Name") instanceof StringTag) {
            // The mob shall be named
            return InteractionResult.SUCCESS;
        }
        return InteractionResult.PASS;
    }

    public void updateArmor(GeyserSession session) {
        if (!valid) return;

        ItemData helmet = this.helmet;
        ItemData chestplate = this.chestplate;
        // If an entity has a banner on them, it will be in the helmet slot in Java but the chestplate spot in Bedrock
        // But don't overwrite the chestplate if it isn't empty
        ItemMapping banner = session.getItemMappings().getStoredItems().banner();
        if (chestplate.getId() == ItemData.AIR.getId() && helmet.getId() == banner.getBedrockId()) {
            chestplate = this.helmet;
            helmet = ItemData.AIR;
        } else if (chestplate.getId() == banner.getBedrockId()) {
            // Prevent chestplate banners from showing erroneously
            chestplate = ItemData.AIR;
        }

        MobArmorEquipmentPacket armorEquipmentPacket = new MobArmorEquipmentPacket();
        armorEquipmentPacket.setRuntimeEntityId(geyserId);
        armorEquipmentPacket.setHelmet(helmet);
        armorEquipmentPacket.setChestplate(chestplate);
        armorEquipmentPacket.setLeggings(leggings);
        armorEquipmentPacket.setBoots(boots);

        session.sendUpstreamPacket(armorEquipmentPacket);
    }

    public void updateMainHand(GeyserSession session) {
        if (!valid) return;

        MobEquipmentPacket handPacket = new MobEquipmentPacket();
        handPacket.setRuntimeEntityId(geyserId);
        handPacket.setItem(hand);
        handPacket.setHotbarSlot(-1);
        handPacket.setInventorySlot(0);
        handPacket.setContainerId(ContainerId.INVENTORY);

        session.sendUpstreamPacket(handPacket);
    }

    public void updateOffHand(GeyserSession session) {
        if (!valid) return;

        MobEquipmentPacket offHandPacket = new MobEquipmentPacket();
        offHandPacket.setRuntimeEntityId(geyserId);
        offHandPacket.setItem(offHand);
        offHandPacket.setHotbarSlot(-1);
        offHandPacket.setInventorySlot(0);
        offHandPacket.setContainerId(ContainerId.OFFHAND);

        session.sendUpstreamPacket(offHandPacket);
    }

    /**
     * Attributes are properties of an entity that are generally more runtime-based instead of permanent properties.
     * Movement speed, current attack damage with a weapon, current knockback resistance.
     *
     * @param attributes the Java list of attributes sent from the server
     */
    public void updateBedrockAttributes(GeyserSession session, List<Attribute> attributes) {
        if (!valid) return;

        List<AttributeData> newAttributes = new ArrayList<>();

        for (Attribute attribute : attributes) {
            // Convert the attribute to a Bedrock version, if relevant
            updateAttribute(attribute, newAttributes);
        }

        if (newAttributes.isEmpty()) {
            // If there are Java-only attributes or only attributes that are not translated by us
            return;
        }

        UpdateAttributesPacket updateAttributesPacket = new UpdateAttributesPacket();
        updateAttributesPacket.setRuntimeEntityId(geyserId);
        updateAttributesPacket.setAttributes(newAttributes);
        session.sendUpstreamPacket(updateAttributesPacket);
    }

    /**
     * Takes the Java attribute and adds it to newAttributes as a Bedrock-formatted attribute
     */
    protected void updateAttribute(Attribute javaAttribute, List<AttributeData> newAttributes) {
        if (javaAttribute.getType() instanceof AttributeType.Builtin type) {
            switch (type) {
                case GENERIC_MAX_HEALTH -> {
                    this.maxHealth = (float) AttributeUtils.calculateValue(javaAttribute);
                    newAttributes.add(createHealthAttribute());
                }
                case GENERIC_ATTACK_DAMAGE -> newAttributes.add(calculateAttribute(javaAttribute, GeyserAttributeType.ATTACK_DAMAGE));
                case GENERIC_FLYING_SPEED -> newAttributes.add(calculateAttribute(javaAttribute, GeyserAttributeType.FLYING_SPEED));
                case GENERIC_MOVEMENT_SPEED -> newAttributes.add(calculateAttribute(javaAttribute, GeyserAttributeType.MOVEMENT_SPEED));
                case GENERIC_FOLLOW_RANGE -> newAttributes.add(calculateAttribute(javaAttribute, GeyserAttributeType.FOLLOW_RANGE));
                case GENERIC_KNOCKBACK_RESISTANCE -> newAttributes.add(calculateAttribute(javaAttribute, GeyserAttributeType.KNOCKBACK_RESISTANCE));
                case HORSE_JUMP_STRENGTH -> newAttributes.add(calculateAttribute(javaAttribute, GeyserAttributeType.HORSE_JUMP_STRENGTH));
            }
        }
    }

    /**
     * Calculates the complete attribute value to send to Bedrock. Will be overriden if attributes need to be cached.
     */
    protected AttributeData calculateAttribute(Attribute javaAttribute, GeyserAttributeType type) {
        return type.getAttribute((float) AttributeUtils.calculateValue(javaAttribute));
    }
}