Fix codecs jank

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

@@ -7,15 +7,11 @@ import java.util.function.Predicate;
 import java.util.function.Supplier;
 
 import com.google.common.base.Suppliers;
-import com.google.gson.JsonParseException;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.item.EnchantableItem;
+import com.minelittlepony.unicopia.util.CodecUtils;
 import com.mojang.datafixers.util.Pair;
 import com.mojang.serialization.Codec;
-import com.mojang.serialization.DataResult;
-import com.mojang.serialization.Decoder;
-import com.mojang.serialization.DynamicOps;
-import com.mojang.serialization.Encoder;
 import net.minecraft.item.ItemStack;
 import net.minecraft.network.PacketByteBuf;
 import net.minecraft.recipe.Ingredient;
@@ -25,23 +21,11 @@ public class IngredientWithSpell implements Predicate<ItemStack> {
     private static final IngredientWithSpell EMPTY = new IngredientWithSpell(Optional.empty(), Optional.empty());
     private static final Predicate<Ingredient> INGREDIENT_IS_PRESENT = ((Predicate<Ingredient>)(Ingredient::isEmpty)).negate();
 
-    public static final Codec<IngredientWithSpell> CODEC = Codec.of(new Encoder<IngredientWithSpell>() {
+    public static final Codec<IngredientWithSpell> CODEC = CodecUtils.extend(Ingredient.ALLOW_EMPTY_CODEC, SpellType.REGISTRY.getCodec().fieldOf("spell")).xmap(
-        @Override
+        pair -> new IngredientWithSpell(pair.getFirst(), pair.getSecond()),
-        public <T> DataResult<T> encode(IngredientWithSpell input, DynamicOps<T> ops, T prefix) {
+        ingredient -> new Pair<>(ingredient.stack, ingredient.spell)
-            throw new JsonParseException("cannot serialize this type");
+    );
-        }
+
-    }, new Decoder<IngredientWithSpell>() {
-        @Override
-        public <T> DataResult<Pair<IngredientWithSpell, T>> decode(DynamicOps<T> ops, T input) {
-            // TODO: Doing codecs properly is an exercise left to the readers
-            return DataResult.success(new Pair<>(
-                new IngredientWithSpell(
-                    Ingredient.ALLOW_EMPTY_CODEC.decode(ops, input).map(Pair::getFirst).result(),
-                    ops.getMap(input).flatMap(maplike -> SpellType.REGISTRY.getCodec().parse(ops, maplike.get("spell"))).result()
-                ), input)
-            );
-        }
-    });
     public static final Codec<DefaultedList<IngredientWithSpell>> LIST_CODEC = CODEC.listOf().xmap(
             list -> DefaultedList.<IngredientWithSpell>copyOf(EMPTY, list.toArray(IngredientWithSpell[]::new)),
             Function.identity()

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

@@ -10,6 +10,7 @@ import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.container.inventory.SpellbookInventory;
 import com.minelittlepony.unicopia.item.EnchantableItem;
 import com.minelittlepony.unicopia.item.URecipes;
+import com.minelittlepony.unicopia.util.CodecUtils;
 import com.minelittlepony.unicopia.util.InventoryUtil;
 import com.mojang.datafixers.util.Pair;
 import com.mojang.serialization.Codec;
@@ -45,9 +46,9 @@ public class SpellCraftingRecipe implements SpellbookRecipe {
     /**
      * The resulting item
      */
-    final ItemStackWithSpell output;
+    final ItemStack output;
 
-    private SpellCraftingRecipe(IngredientWithSpell material, TraitIngredient requiredTraits, List<IngredientWithSpell> requiredItems, ItemStackWithSpell output) {
+    private SpellCraftingRecipe(IngredientWithSpell material, TraitIngredient requiredTraits, List<IngredientWithSpell> requiredItems, ItemStack output) {
         this.material = material;
         this.requiredTraits = requiredTraits;
         this.requiredItems = requiredItems;
@@ -63,7 +64,7 @@ public class SpellCraftingRecipe implements SpellbookRecipe {
         requiredTraits.min().ifPresent(min -> {
             min.forEach(e -> builder.input(e.getKey(), e.getValue()));
         });
-        builder.result(output.toItemStack());
+        builder.result(output);
     }
 
     @Override
@@ -115,7 +116,7 @@ public class SpellCraftingRecipe implements SpellbookRecipe {
 
     @Override
     public ItemStack getResult(DynamicRegistryManager registries) {
-        return output.toItemStack();
+        return output;
     }
 
     @Override
@@ -123,29 +124,17 @@ public class SpellCraftingRecipe implements SpellbookRecipe {
         return URecipes.TRAIT_REQUIREMENT;
     }
 
-    record ItemStackWithSpell(ItemStack stack, Optional<SpellType<?>> spell) {
-        public static final Codec<ItemStackWithSpell> CODEC = RecordCodecBuilder.create(instance -> instance.group(
-                RecipeCodecs.CRAFTING_RESULT.fieldOf("stack").forGetter(ItemStackWithSpell::stack),
-                SpellType.REGISTRY.getCodec().optionalFieldOf("spell").forGetter(ItemStackWithSpell::spell)
-        ).apply(instance, ItemStackWithSpell::new));
-
-        public ItemStack toItemStack() {
-            return spell.filter(s -> s != SpellType.EMPTY_KEY).map(s -> {
-                return EnchantableItem.enchant(stack.copy(), s);
-            }).orElse(stack);
-        }
-
-        public ItemStackWithSpell(ItemStack stack) {
-            this(EnchantableItem.unenchant(stack), Optional.of(EnchantableItem.getSpellKey(stack)));
-        }
-    }
-
     public static class Serializer implements RecipeSerializer<SpellCraftingRecipe> {
+        private static final Codec<ItemStack> RESULT_CODEC = CodecUtils.extend(RecipeCodecs.CRAFTING_RESULT, SpellType.REGISTRY.getCodec().fieldOf("spell")).xmap(
+                pair -> pair.getSecond().map(spell -> EnchantableItem.enchant(pair.getFirst().orElse(ItemStack.EMPTY), spell)).orElse(pair.getFirst().orElse(ItemStack.EMPTY)),
+                stack -> Pair.of(Optional.of(stack), EnchantableItem.getSpellKeyOrEmpty(stack))
+        );
+
         private static final Codec<SpellCraftingRecipe> CODEC = RecordCodecBuilder.<SpellCraftingRecipe>create(instance -> instance.group(
                 IngredientWithSpell.CODEC.fieldOf("material").forGetter(recipe -> recipe.material),
                 TraitIngredient.CODEC.fieldOf("traits").forGetter(recipe -> recipe.requiredTraits),
                 IngredientWithSpell.CODEC.listOf().fieldOf("ingredients").forGetter(recipe -> recipe.requiredItems),
-                ItemStackWithSpell.CODEC.fieldOf("result").forGetter(recipe -> recipe.output)
+                RESULT_CODEC.fieldOf("result").forGetter(recipe -> recipe.output)
         ).apply(instance, SpellCraftingRecipe::new));
 
         @Override
@@ -159,7 +148,7 @@ public class SpellCraftingRecipe implements SpellbookRecipe {
                     IngredientWithSpell.fromPacket(buf),
                     TraitIngredient.fromPacket(buf),
                     buf.readCollection(DefaultedList::ofSize, IngredientWithSpell::fromPacket),
-                    new ItemStackWithSpell(buf.readItemStack())
+                    buf.readItemStack()
             );
         }
 
@@ -168,7 +157,7 @@ public class SpellCraftingRecipe implements SpellbookRecipe {
             recipe.material.write(buf);
             recipe.requiredTraits.write(buf);
             buf.writeCollection(recipe.requiredItems, (b, i) -> i.write(b));
-            buf.writeItemStack(recipe.output.toItemStack());
+            buf.writeItemStack(recipe.output);
         }
     }
 }

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/trait/Trait.java

@@ -163,7 +163,7 @@ public enum Trait implements CommandArgumentEnum<Trait> {
 
     @Deprecated
     public static Optional<Trait> fromId(Identifier id) {
-        return Optional.ofNullable(ID_CODEC.byId(id.toString()));
+        return Optional.ofNullable(IDS.get(id));
     }
 
     @Deprecated

src/main/java/com/minelittlepony/unicopia/advancement/UCriteria.java

@@ -3,9 +3,9 @@ package com.minelittlepony.unicopia.advancement;
 import net.minecraft.advancement.criterion.Criteria;
 
 public interface UCriteria {
-    CustomEventCriterion CUSTOM_EVENT = Criteria.register("unicopia:send_dragon_breath", new CustomEventCriterion());
+    CustomEventCriterion CUSTOM_EVENT = Criteria.register("unicopia:custom", new CustomEventCriterion());
     RaceChangeCriterion PLAYER_CHANGE_RACE = Criteria.register("unicopia:player_change_race", new RaceChangeCriterion());
-    SendViaDragonBreathScrollCriterion SEND_DRAGON_BREATH = Criteria.register("unicopia:custom", new SendViaDragonBreathScrollCriterion());
+    SendViaDragonBreathScrollCriterion SEND_DRAGON_BREATH = Criteria.register("unicopia:send_dragon_breath", new SendViaDragonBreathScrollCriterion());
 
     CustomEventCriterion.Trigger LOOK_INTO_SUN = CUSTOM_EVENT.createTrigger("look_into_sun");
     CustomEventCriterion.Trigger WEAR_SHADES = CUSTOM_EVENT.createTrigger("wear_shades");

src/main/java/com/minelittlepony/unicopia/item/EnchantableItem.java

@@ -1,5 +1,6 @@
 package com.minelittlepony.unicopia.item;
 
+import java.util.Optional;
 import java.util.function.Predicate;
 
 import org.jetbrains.annotations.Nullable;
@@ -83,6 +84,10 @@ public interface EnchantableItem extends ItemConvertible {
         return stack;
     }
 
+    static Optional<SpellType<?>> getSpellKeyOrEmpty(ItemStack stack) {
+        return isEnchanted(stack) ? SpellType.REGISTRY.getOrEmpty(new Identifier(stack.getNbt().getString("spell"))) : Optional.empty();
+    }
+
     static <T extends Spell> SpellType<T> getSpellKey(ItemStack stack) {
         return SpellType.getKey(isEnchanted(stack) ? new Identifier(stack.getNbt().getString("spell")) : SpellType.EMPTY_ID);
     }

src/main/java/com/minelittlepony/unicopia/item/ZapAppleRecipe.java

@@ -20,12 +20,11 @@ public class ZapAppleRecipe extends ShapelessRecipe {
     public static class Serializer implements RecipeSerializer<ZapAppleRecipe> {
         private static final Codec<ZapAppleRecipe> CODEC = RecordCodecBuilder.create(instance -> instance.group(
             Codec.STRING.optionalFieldOf("group", "").forGetter(ZapAppleRecipe::getGroup),
-            CraftingRecipeCategory.CODEC.fieldOf("category").forGetter(ZapAppleRecipe::getCategory),
+            CraftingRecipeCategory.CODEC.optionalFieldOf("category", CraftingRecipeCategory.MISC).forGetter(ZapAppleRecipe::getCategory),
-            Registries.ITEM.getCodec().xmap(item -> {
+            Registries.ITEM.getCodec().xmap(
-                return UItems.ZAP_APPLE.setAppearance(UItems.ZAP_APPLE.getDefaultStack(), item.getDefaultStack());
+                item -> UItems.ZAP_APPLE.setAppearance(UItems.ZAP_APPLE.getDefaultStack(), item.getDefaultStack()),
-            }, stack -> {
+                stack -> UItems.ZAP_APPLE.getAppearance(stack)
-                return UItems.ZAP_APPLE.getAppearance(stack);
+            ).fieldOf("appearance").forGetter(recipe -> recipe.getResult(null)),
-            }).fieldOf("appearance").forGetter(recipe -> recipe.getResult(null)),
             URecipes.SHAPELESS_RECIPE_INGREDIENTS_CODEC.fieldOf("ingredients").forGetter(ZapAppleRecipe::getIngredients)
         ).apply(instance, ZapAppleRecipe::new));
 

src/main/java/com/minelittlepony/unicopia/util/CodecUtils.java

@@ -0,0 +1,61 @@
+package com.minelittlepony.unicopia.util;
+
+import java.util.Optional;
+
+import com.mojang.datafixers.util.Pair;
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.DataResult;
+import com.mojang.serialization.Decoder;
+import com.mojang.serialization.DynamicOps;
+import com.mojang.serialization.Encoder;
+import com.mojang.serialization.MapCodec;
+
+public interface CodecUtils {
+    /**
+     * Combines the result of two unrelated codecs into a single object.
+     * <p>
+     * The first codec serves as the "base" whilst the second codec serves as an additional field to merge into
+     * that object when serializing. Deserializing produces a pair with the parent value and the extra value.
+     * <p>
+     * Recommended usage:
+     * <code>
+     * Codec<MyObject> CODEC = CodecUtils.extend(SOME_CODEC, MY_FIELD_CODEC.fieldOf("my_extra_field")).xmap(
+     *      pair -> new MyObject(pair.getLeft(), pair.getRight()),
+     *      myObject -> Pair.of(myObject.parent(), myObject.myExtraField());
+     * </code>
+     * <p>
+     * Json:
+     * <code>
+     * {
+     *   "something": "something",
+     *   "something_else": 1,
+     *
+     *   "my_extra_field": "HAH EAT THAT CODECS"
+     * }
+     * </code>
+     * @param <A> The base type
+     * @param <B> Type of the field to append
+     * @param baseCodec   Codec for the base type
+     * @param fieldCodec  Codec for the appended field
+     * @return A codec for serializing objects of the base with the extra field inserted
+     */
+    static <A, B> Codec<Pair<Optional<A>, Optional<B>>> extend(Codec<A> baseCodec, MapCodec<B> fieldCodec) {
+        return Codec.of(new Encoder<Pair<Optional<A>, Optional<B>>>() {
+            @Override
+            public <T> DataResult<T> encode(Pair<Optional<A>, Optional<B>> input, DynamicOps<T> ops, T prefix) {
+                return baseCodec.encode(input.getFirst().get(), ops, prefix)
+                        .flatMap(leftResult -> input.getSecond()
+                            .map(r -> fieldCodec.encode(r, ops, ops.mapBuilder()).build(prefix))
+                            .orElse(DataResult.success(leftResult)));
+            }
+        }, new Decoder<Pair<Optional<A>, Optional<B>>>() {
+            @Override
+            public <T> DataResult<Pair<Pair<Optional<A>, Optional<B>>, T>> decode(DynamicOps<T> ops, T input) {
+                return DataResult.success(new Pair<>(new Pair<>(
+                        baseCodec.decode(ops, input).map(Pair::getFirst).result(),
+                        fieldCodec.decode(ops, ops.getMap(input).result().get()).result()
+                ), input));
+            }
+        });
+    }
+}

src/main/resources/data/unicopia/loot_tables/blocks/apple_pie.json

@@ -16,7 +16,7 @@
               "block": "unicopia:apple_pie",
               "condition": "minecraft:block_state_property",
               "properties": {
-                "stomped": true
+                "stomped": "true"
               }
             },
             {