Some minor cleanup

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/CompoundSpell.java

@@ -38,7 +38,7 @@ public class CompoundSpell extends AbstractDelegatingSpell {
     public void toNBT(NbtCompound compound) {
         super.toNBT(compound);
         NbtList spells = new NbtList();
-        this.spells.stream().map(SpellType::toNBT).forEach(spells::add);
+        this.spells.stream().map(Spell::writeNbt).forEach(spells::add);
         compound.put("spells", spells);
     }
 
@@ -48,7 +48,7 @@ public class CompoundSpell extends AbstractDelegatingSpell {
         spells.clear();
         if (compound.contains("spells", NbtElement.LIST_TYPE)) {
             spells.addAll(compound.getList("spells", NbtElement.COMPOUND_TYPE).stream()
-                .map(el -> SpellType.fromNBT((NbtCompound)el))
+                .map(el -> Spell.readNbt((NbtCompound)el))
                 .filter(Objects::nonNull)
                 .toList());
         }

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/PlaceableSpell.java

@@ -102,7 +102,7 @@ public class PlaceableSpell extends AbstractDelegatingSpell {
             compound.putString("dimension", dimension.toString());
         }
         compound.put("castEntity", castEntity.toNBT());
-        compound.put("spell", SpellType.toNBT(spell));
+        compound.put("spell", Spell.writeNbt(spell));
     }
 
     @Override
@@ -114,7 +114,7 @@ public class PlaceableSpell extends AbstractDelegatingSpell {
         if (compound.contains("castEntity")) {
             castEntity.fromNBT(compound.getCompound("castEntity"));
         }
-        spell = SpellType.fromNBT(compound.getCompound("spell"));
+        spell = Spell.readNbt(compound.getCompound("spell"));
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/Spell.java

@@ -4,6 +4,7 @@ import java.util.UUID;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
 
+import org.jetbrains.annotations.Nullable;
 import org.spongepowered.include.com.google.common.base.Objects;
 
 import com.minelittlepony.unicopia.ability.magic.Affine;
@@ -12,6 +13,8 @@ import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.util.NbtSerialisable;
 
+import net.minecraft.nbt.NbtCompound;
+
 /**
  * Interface for a magic spells
  */
@@ -104,4 +107,25 @@ public interface Spell extends NbtSerialisable, Affine {
     default ThrowableSpell toThrowable() {
         return SpellType.THROWN_SPELL.create(SpellTraits.EMPTY).setSpell(this);
     }
+
+    @Nullable
+    static Spell readNbt(@Nullable NbtCompound compound) {
+        if (compound != null && compound.contains("effect_id")) {
+            Spell effect = SpellType.getKey(compound).create(SpellTraits.EMPTY);
+
+            if (effect != null) {
+                effect.fromNBT(compound);
+            }
+
+            return effect;
+        }
+
+        return null;
+    }
+
+    static NbtCompound writeNbt(Spell effect) {
+        NbtCompound compound = effect.toNBT();
+        effect.getType().toNbt(compound);
+        return compound;
+    }
 }

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/ThrowableSpell.java

@@ -74,13 +74,13 @@ public final class ThrowableSpell extends AbstractDelegatingSpell {
     @Override
     public void toNBT(NbtCompound compound) {
         super.toNBT(compound);
-        compound.put("spell", SpellType.toNBT(spell));
+        compound.put("spell", Spell.writeNbt(spell));
     }
 
     @Override
     public void fromNBT(NbtCompound compound) {
         super.fromNBT(compound);
-        spell = SpellType.fromNBT(compound.getCompound("spell"));
+        spell = Spell.readNbt(compound.getCompound("spell"));
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/crafting/IngredientWithSpell.java

@@ -61,7 +61,7 @@ public class IngredientWithSpell implements Predicate<ItemStack> {
             ingredient.stack = Optional.ofNullable(Ingredient.fromPacket(buf));
         }
         if (buf.readBoolean()) {
-            ingredient.spell = Optional.of(SpellType.getKey(buf.readIdentifier()));
+            ingredient.spell = SpellType.REGISTRY.getOrEmpty(buf.readIdentifier());
         }
 
         return ingredient;
@@ -76,7 +76,7 @@ public class IngredientWithSpell implements Predicate<ItemStack> {
                 ingredient.stack = Optional.ofNullable(Ingredient.fromJson(JsonHelper.getObject(json, "item")));
             }
             if (json.has("spell")) {
-                ingredient.spell = Optional.ofNullable(Identifier.tryParse(JsonHelper.getString(json, "spell"))).map(SpellType::getKey);
+                ingredient.spell = SpellType.REGISTRY.getOrEmpty(Identifier.tryParse(JsonHelper.getString(json, "spell")));
             }
         } else {
             ingredient.stack = Optional.ofNullable(Ingredient.fromJson(json));

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/CustomisedSpellType.java

@@ -44,7 +44,7 @@ public record CustomisedSpellType<T extends Spell> (
 
     public NbtCompound toNBT() {
         NbtCompound tag = new NbtCompound();
-        type.writeId(tag);
+        type.toNbt(tag);
         tag.put("traits", traits.toNbt());
         return tag;
     }

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/SpellType.java

@@ -3,7 +3,6 @@ package com.minelittlepony.unicopia.ability.magic.spell.effect;
 import java.util.EnumMap;
 import java.util.HashSet;
 import java.util.Map;
-import java.util.Random;
 import java.util.Set;
 
 import org.jetbrains.annotations.Nullable;
@@ -36,15 +35,15 @@ public final class SpellType<T extends Spell> implements Affine, SpellPredicate<
     public static final Identifier EMPTY_ID = new Identifier("unicopia", "none");
     public static final SpellType<?> EMPTY_KEY = new SpellType<>(EMPTY_ID, Affinity.NEUTRAL, 0xFFFFFF, false, SpellTraits.EMPTY, (t, c) -> null);
 
-    private static final Registry<SpellType<?>> REGISTRY = Registries.createSimple(new Identifier("unicopia", "spells"));
+    public static final Registry<SpellType<?>> REGISTRY = Registries.createSimple(new Identifier("unicopia", "spells"));
     private static final Map<Affinity, Set<SpellType<?>>> BY_AFFINITY = new EnumMap<>(Affinity.class);
 
-    public static final SpellType<CompoundSpell> COMPOUND_SPELL = register("compound", Affinity.NEUTRAL, 0, false, CompoundSpell::new);
+    public static final SpellType<CompoundSpell> COMPOUND_SPELL = register("compound", Affinity.NEUTRAL, 0, false, SpellTraits.EMPTY, CompoundSpell::new);
-    public static final SpellType<PlaceableSpell> PLACED_SPELL = register("placed", Affinity.NEUTRAL, 0, false, PlaceableSpell::new);
+    public static final SpellType<PlaceableSpell> PLACED_SPELL = register("placed", Affinity.NEUTRAL, 0, false, SpellTraits.EMPTY, PlaceableSpell::new);
-    public static final SpellType<ThrowableSpell> THROWN_SPELL = register("thrown", Affinity.NEUTRAL, 0, false, ThrowableSpell::new);
+    public static final SpellType<ThrowableSpell> THROWN_SPELL = register("thrown", Affinity.NEUTRAL, 0, false, SpellTraits.EMPTY, ThrowableSpell::new);
 
-    public static final SpellType<AbstractDisguiseSpell> CHANGELING_DISGUISE = register("disguise", Affinity.BAD, 0x19E48E, false, DispersableDisguiseSpell::new);
+    public static final SpellType<AbstractDisguiseSpell> CHANGELING_DISGUISE = register("disguise", Affinity.BAD, 0x19E48E, false, SpellTraits.EMPTY, DispersableDisguiseSpell::new);
-    public static final SpellType<RainboomAbilitySpell> RAINBOOM = register("rainboom", Affinity.GOOD, 0xBDBDF9, false, RainboomAbilitySpell::new);
+    public static final SpellType<RainboomAbilitySpell> RAINBOOM = register("rainboom", Affinity.GOOD, 0xBDBDF9, false, SpellTraits.EMPTY, RainboomAbilitySpell::new);
 
     public static final SpellType<IceSpell> FROST = register("frost", Affinity.GOOD, 0xBDBDF9, true, IceSpell.DEFAULT_TRAITS, IceSpell::new);
     public static final SpellType<ScorchSpell> SCORCH = register("scorch", Affinity.BAD, 0, true, ScorchSpell.DEFAULT_TRAITS, ScorchSpell::new);
@@ -166,10 +165,23 @@ public final class SpellType<T extends Spell> implements Affine, SpellPredicate<
         return spell != null && spell.getType() == this;
     }
 
+    public void toNbt(NbtCompound tag) {
+        tag.putString("effect_id", getId().toString());
+    }
+
     public boolean isEmpty() {
         return this == EMPTY_KEY;
     }
 
+    @Deprecated(forRemoval = true)
+    public static <T extends Spell> SpellType<T> register(String name, Affinity affinity, int color, boolean obtainable, Factory<T> factory) {
+        return register(name, affinity, color, obtainable, SpellTraits.EMPTY, factory);
+    }
+
+    public static <T extends Spell> SpellType<T> register(String name, Affinity affinity, int color, boolean obtainable, SpellTraits traits, Factory<T> factory) {
+        return register(new Identifier("unicopia", name), affinity, color, obtainable, traits, factory);
+    }
+
     public static <T extends Spell> SpellType<T> register(Identifier id, Affinity affinity, int color, boolean obtainable, SpellTraits traits, Factory<T> factory) {
         SpellType<T> type = new SpellType<>(id, affinity, color, obtainable, traits, factory);
         byAffinity(affinity).add(type);
@@ -177,14 +189,6 @@ public final class SpellType<T extends Spell> implements Affine, SpellPredicate<
         return type;
     }
 
-    public static <T extends Spell> SpellType<T> register(String name, Affinity affinity, int color, boolean obtainable, Factory<T> factory) {
-        return register(name, affinity, color, obtainable, SpellTraits.EMPTY, factory);
-    }
-
-    public static <T extends Spell> SpellType<T> register(String name, Affinity affinity, int color, boolean obtainable, SpellTraits traits, Factory<T> factory) {
-        return register(new Identifier("unicopia", name), affinity, color, obtainable, traits, factory);
-    }
-
     @SuppressWarnings("unchecked")
     public static <T extends Spell> SpellType<T> empty() {
         return (SpellType<T>)EMPTY_KEY;
@@ -196,42 +200,13 @@ public final class SpellType<T extends Spell> implements Affine, SpellPredicate<
 
     @SuppressWarnings("unchecked")
     public static <T extends Spell> SpellType<T> getKey(@Nullable Identifier id) {
-        return (SpellType<T>)(id == null || EMPTY_ID.equals(id) ? EMPTY_KEY : REGISTRY.getOrEmpty(id).orElse(EMPTY_KEY));
+        return (SpellType<T>)REGISTRY.get(id);
-    }
-
-    public static SpellType<?> random(Random random) {
-        return REGISTRY.getRandom(random);
     }
 
     public static Set<SpellType<?>> byAffinity(Affinity affinity) {
         return BY_AFFINITY.computeIfAbsent(affinity, a -> new HashSet<>());
     }
 
-    @Nullable
-    public static Spell fromNBT(@Nullable NbtCompound compound) {
-        if (compound != null && compound.contains("effect_id")) {
-            Spell effect = getKey(compound).create(SpellTraits.EMPTY);
-
-            if (effect != null) {
-                effect.fromNBT(compound);
-            }
-
-            return effect;
-        }
-
-        return null;
-    }
-
-    public static NbtCompound toNBT(Spell effect) {
-        NbtCompound compound = effect.toNBT();
-        effect.getType().writeId(compound);
-        return compound;
-    }
-
-    public void writeId(NbtCompound tag) {
-        tag.putString("effect_id", getId().toString());
-    }
-
     public interface Factory<T extends Spell> {
         T create(SpellType<T> type, SpellTraits traits);
     }

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

@@ -4,7 +4,7 @@ import com.minelittlepony.unicopia.Affinity;
 import com.minelittlepony.unicopia.Race;
 import com.minelittlepony.unicopia.ability.magic.Affine;
 import com.minelittlepony.unicopia.ability.magic.Levelled;
-import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
+import com.minelittlepony.unicopia.ability.magic.spell.Spell;
 import com.minelittlepony.unicopia.entity.ai.BreakHeartGoal;
 import com.minelittlepony.unicopia.entity.ai.DynamicTargetGoal;
 import com.minelittlepony.unicopia.entity.ai.WantItTakeItGoal;
@@ -97,7 +97,7 @@ public class Creature extends Living<LivingEntity> {
     public void toNBT(NbtCompound compound) {
         super.toNBT(compound);
         getSpellSlot().get(true).ifPresent(effect -> {
-            compound.put("effect", SpellType.toNBT(effect));
+            compound.put("effect", Spell.writeNbt(effect));
         });
         physics.toNBT(compound);
     }
@@ -106,7 +106,7 @@ public class Creature extends Living<LivingEntity> {
     public void fromNBT(NbtCompound compound) {
         super.fromNBT(compound);
         if (compound.contains("effect")) {
-            getSpellSlot().put(SpellType.fromNBT(compound.getCompound("effect")));
+            getSpellSlot().put(Spell.readNbt(compound.getCompound("effect")));
         }
         physics.fromNBT(compound);
     }

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

@@ -36,7 +36,7 @@ public interface UTradeOffers {
 
         TradeOfferHelper.registerWanderingTraderOffers(1, factories -> {
             factories.add(buyTiered(UItems.GEMSTONE, 30, UItems.GOLDEN_FEATHER, 1, UItems.GOLDEN_WING, 1, 30, 2, 0.05F));
-            factories.add((e, rng) -> new TradeOffer(new ItemStack(UItems.GEMSTONE, 3), GemstoneItem.enchant(UItems.GEMSTONE.getDefaultStack(), SpellType.random(rng)), 20, 1, 0.05F));
+            factories.add((e, rng) -> new TradeOffer(new ItemStack(UItems.GEMSTONE, 3), GemstoneItem.enchant(UItems.GEMSTONE.getDefaultStack(), SpellType.REGISTRY.getRandom(rng)), 20, 1, 0.05F));
             factories.add(buy(UItems.GEMSTONE, 20, UItems.HAY_FRIES, 5, 50, 3, 0.06F));
             factories.add(buy(Items.WHEAT, 17, UItems.HAY_BURGER, 1, 10, 6, 0.08F));
             factories.add(buy(ItemTags.SMALL_FLOWERS, 2, UItems.DAFFODIL_DAISY_SANDWICH, 1, 10, 6, 0.08F));

src/main/java/com/minelittlepony/unicopia/entity/player/Pony.java

@@ -482,7 +482,7 @@ public class Pony extends Living<PlayerEntity> implements Transmittable, Copieab
         compound.put("discoveries", discoveries.toNBT());
 
         getSpellSlot().get(true).ifPresent(effect ->{
-            compound.put("effect", SpellType.toNBT(effect));
+            compound.put("effect", Spell.writeNbt(effect));
         });
     }
 
@@ -500,7 +500,7 @@ public class Pony extends Living<PlayerEntity> implements Transmittable, Copieab
         magicExhaustion = compound.getFloat("magicExhaustion");
 
         if (compound.contains("effect")) {
-            getSpellSlot().put(SpellType.fromNBT(compound.getCompound("effect")));
+            getSpellSlot().put(Spell.readNbt(compound.getCompound("effect")));
         }
     }
 

src/main/java/com/minelittlepony/unicopia/network/datasync/SpellNetworkedReference.java

@@ -7,7 +7,6 @@ import org.jetbrains.annotations.Nullable;
 
 import com.minelittlepony.unicopia.ability.magic.Caster;
 import com.minelittlepony.unicopia.ability.magic.spell.Spell;
-import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 
 import net.minecraft.nbt.NbtCompound;
 
@@ -78,7 +77,7 @@ public class SpellNetworkedReference<T extends Spell> implements NetworkedRefere
         }
 
         if (mustReplace(comp)) {
-            updateReference((T)SpellType.fromNBT(comp));
+            updateReference((T)Spell.readNbt(comp));
             return false;
         }
 
@@ -98,7 +97,7 @@ public class SpellNetworkedReference<T extends Spell> implements NetworkedRefere
     @Override
     public NbtCompound toNbt() {
         dirty = false;
-        return getReference().map(SpellType::toNBT).orElseGet(NbtCompound::new);
+        return getReference().map(Spell::writeNbt).orElseGet(NbtCompound::new);
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/projectile/MagicProjectileEntity.java

@@ -12,7 +12,6 @@ import com.minelittlepony.unicopia.ability.magic.SpellContainer;
 import com.minelittlepony.unicopia.ability.magic.SpellPredicate;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.Spell;
-import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.entity.EntityPhysics;
 import com.minelittlepony.unicopia.entity.EntityReference;
 import com.minelittlepony.unicopia.entity.Physics;
@@ -223,7 +222,7 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
         physics.fromNBT(compound);
         homingTarget.fromNBT(compound.getCompound("homingTarget"));
         if (compound.contains("effect")) {
-            getSpellSlot().put(SpellType.fromNBT(compound.getCompound("effect")));
+            getSpellSlot().put(Spell.readNbt(compound.getCompound("effect")));
         }
     }
 
@@ -233,7 +232,7 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
         physics.toNBT(compound);
         compound.put("homingTarget", homingTarget.toNBT());
         getSpellSlot().get(true).ifPresent(effect -> {
-            compound.put("effect", SpellType.toNBT(effect));
+            compound.put("effect", Spell.writeNbt(effect));
         });
     }