Implement the clingy enchantment

src/main/java/com/minelittlepony/unicopia/entity/ItemImpl.java

@@ -1,15 +1,26 @@
 package com.minelittlepony.unicopia.entity;
 
+import java.util.Random;
+
 import com.minelittlepony.unicopia.Owned;
 import com.minelittlepony.unicopia.Race;
+import com.minelittlepony.unicopia.item.enchantment.UEnchantments;
+import com.minelittlepony.unicopia.util.VecHelper;
 
+import net.minecraft.enchantment.EnchantmentHelper;
 import net.minecraft.entity.ItemEntity;
+import net.minecraft.entity.MovementType;
 import net.minecraft.entity.data.DataTracker;
 import net.minecraft.entity.data.TrackedData;
 import net.minecraft.entity.data.TrackedDataHandlerRegistry;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.particle.ParticleEffect;
+import net.minecraft.particle.ParticleTypes;
 import net.minecraft.util.ActionResult;
+import net.minecraft.util.math.Vec3d;
 
 public class ItemImpl implements Equine<ItemEntity>, Owned<ItemEntity> {
     private static final TrackedData<Integer> ITEM_RACE = DataTracker.registerData(ItemEntity.class, TrackedDataHandlerRegistry.INTEGER);
@@ -42,8 +53,41 @@ public class ItemImpl implements Equine<ItemEntity>, Owned<ItemEntity> {
 
         ItemStack stack = owner.getStack();
 
-        if (!stack.isEmpty() && stack.getItem() instanceof TickableItem) {
+        if (!stack.isEmpty()) {
-            return ((TickableItem)stack.getItem()).onGroundTick((IItemEntity)owner) == ActionResult.SUCCESS;
+
+            Item item = stack.getItem();
+            ClingyItem clingy = item instanceof ClingyItem ? (ClingyItem)item : ClingyItem.DEFAULT;
+
+            IItemEntity i = (IItemEntity)owner;
+
+            if (clingy.isClingy(stack)) {
+                Random rng = owner.world.random;
+
+                owner.world.addParticle(clingy.getParticleEffect((IItemEntity)owner),
+                        owner.getX() + rng.nextFloat() - 0.5,
+                        owner.getY() + rng.nextFloat() - 0.5,
+                        owner.getZ() + rng.nextFloat() - 0.5,
+                        0, 0, 0
+                );
+
+                Vec3d position = owner.getPos();
+                VecHelper.findInRange(owner, owner.world, owner.getPos(), clingy.getFollowDistance(i), e -> e instanceof PlayerEntity)
+                    .stream()
+                    .sorted((a, b) -> (int)(a.getPos().distanceTo(position) - b.getPos().distanceTo(position)))
+                    .findFirst()
+                    .ifPresent(player -> {
+                        owner.move(MovementType.SELF, player.getPos().subtract(owner.getPos()).multiply(clingy.getFollowSpeed(i)));
+                        if (owner.horizontalCollision) {
+                            owner.move(MovementType.SELF, new Vec3d(0, owner.verticalCollision ? -0.3 : 0.3, 0));
+                        }
+
+                        clingy.interactWithPlayer(i, (PlayerEntity)player);
+                    });
+            }
+
+            if (stack.getItem() instanceof TickableItem) {
+                return ((TickableItem)stack.getItem()).onGroundTick(i) == ActionResult.SUCCESS;
+            }
         }
 
         return false;
@@ -70,7 +114,6 @@ public class ItemImpl implements Equine<ItemEntity>, Owned<ItemEntity> {
         physics.toNBT(compound);
     }
 
-
     @Override
     public void fromNBT(CompoundTag compound) {
         setSpecies(Race.fromName(compound.getString("owner_species")));
@@ -90,4 +133,28 @@ public class ItemImpl implements Equine<ItemEntity>, Owned<ItemEntity> {
     public interface TickableItem {
         ActionResult onGroundTick(IItemEntity entity);
     }
+
+    public interface ClingyItem {
+        ClingyItem DEFAULT = stack -> {
+            return EnchantmentHelper.getLevel(UEnchantments.CLINGY, stack) > 0;
+        };
+
+        boolean isClingy(ItemStack stack);
+
+        default ParticleEffect getParticleEffect(IItemEntity entity) {
+            return ParticleTypes.AMBIENT_ENTITY_EFFECT;
+        }
+
+        default float getFollowDistance(IItemEntity entity) {
+            return 6 * (1 + EnchantmentHelper.getLevel(UEnchantments.CLINGY, entity.get().getMaster().getStack()));
+        }
+
+        default float getFollowSpeed(IItemEntity entity) {
+            return Math.min(1, 0.02F * (1 + EnchantmentHelper.getLevel(UEnchantments.CLINGY, entity.get().getMaster().getStack())));
+        }
+
+        default void interactWithPlayer(IItemEntity entity, PlayerEntity player) {
+
+        }
+    }
 }

src/main/java/com/minelittlepony/unicopia/item/enchantment/UEnchantments.java

@@ -75,7 +75,7 @@ public interface UEnchantments {
     /**
      * This item just wants to be held.
      */
-    Enchantment CLINGY = register("clingy", new SimpleEnchantment(Rarity.VERY_RARE, true, 1, EquipmentSlot.values()));
+    Enchantment CLINGY = register("clingy", new SimpleEnchantment(Rarity.VERY_RARE, true, 6, EquipmentSlot.values()));
 
     static void bootstrap() { }
 

src/main/resources/assets/unicopia/lang/en_us.json

@@ -166,6 +166,8 @@
   
   "enchantment.unicopia.gem_location": "Gem Locator",
   "enchantment.unicopia.padded": "Padded",
+  "enchantment.unicopia.clingy": "Clings",
+  "enchantment.unicopia.repulsion": "Repulsive",
   "enchantment.unicopia.heavy": "Heavy",
   "enchantment.unicopia.collaborator": "Collaborator",
   "enchantment.unicopia.desired": "Want It Need It",