#1499: Make Fluid an interface and add missing entry

By: DerFrZocker <derrieple@gmail.com>

paper-server/src/main/java/org/bukkit/craftbukkit/CraftFluid.java

@@ -1,30 +1,94 @@
 package org.bukkit.craftbukkit;
 
-import com.google.common.base.Preconditions;
-import net.minecraft.core.IRegistry;
+import java.util.Locale;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.world.level.material.FluidType;
 import org.bukkit.Fluid;
+import org.bukkit.NamespacedKey;
 import org.bukkit.Registry;
-import org.bukkit.craftbukkit.util.CraftNamespacedKey;
+import org.bukkit.craftbukkit.util.Handleable;
+import org.jetbrains.annotations.NotNull;
 
-public class CraftFluid {
+public class CraftFluid implements Fluid, Handleable<FluidType> {
+
+    private static int count = 0;
 
     public static Fluid minecraftToBukkit(FluidType minecraft) {
-        Preconditions.checkArgument(minecraft != null);
-
-        IRegistry<FluidType> registry = CraftRegistry.getMinecraftRegistry(Registries.FLUID);
-        Fluid bukkit = Registry.FLUID.get(CraftNamespacedKey.fromMinecraft(registry.getResourceKey(minecraft).orElseThrow().location()));
-
-        Preconditions.checkArgument(bukkit != null);
-
-        return bukkit;
+        return CraftRegistry.minecraftToBukkit(minecraft, Registries.FLUID, Registry.FLUID);
     }
 
     public static FluidType bukkitToMinecraft(Fluid bukkit) {
-        Preconditions.checkArgument(bukkit != null);
+        return CraftRegistry.bukkitToMinecraft(bukkit);
+    }
 
-        return CraftRegistry.getMinecraftRegistry(Registries.FLUID)
-                .getOptional(CraftNamespacedKey.toMinecraft(bukkit.getKey())).orElseThrow();
+    private final NamespacedKey key;
+    private final FluidType fluidType;
+    private final String name;
+    private final int ordinal;
+
+    public CraftFluid(NamespacedKey key, FluidType fluidType) {
+        this.key = key;
+        this.fluidType = fluidType;
+        // For backwards compatibility, minecraft values will stile return the uppercase name without the namespace,
+        // in case plugins use for example the name as key in a config file to receive fluid specific values.
+        // Custom fluids will return the key with namespace. For a plugin this should look than like a new fluid
+        // (which can always be added in new minecraft versions and the plugin should therefore handle it accordingly).
+        if (NamespacedKey.MINECRAFT.equals(key.getNamespace())) {
+            this.name = key.getKey().toUpperCase(Locale.ROOT);
+        } else {
+            this.name = key.toString();
+        }
+        this.ordinal = count++;
+    }
+
+    @Override
+    public FluidType getHandle() {
+        return fluidType;
+    }
+
+    @NotNull
+    @Override
+    public NamespacedKey getKey() {
+        return key;
+    }
+
+    @Override
+    public int compareTo(@NotNull Fluid fluid) {
+        return ordinal - fluid.ordinal();
+    }
+
+    @NotNull
+    @Override
+    public String name() {
+        return name;
+    }
+
+    @Override
+    public int ordinal() {
+        return ordinal;
+    }
+
+    @Override
+    public String toString() {
+        // For backwards compatibility
+        return name();
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+
+        if (!(other instanceof CraftFluid otherFluid)) {
+            return false;
+        }
+
+        return getKey().equals(otherFluid.getKey());
+    }
+
+    @Override
+    public int hashCode() {
+        return getKey().hashCode();
     }
 }

paper-server/src/main/java/org/bukkit/craftbukkit/CraftRegistry.java

@@ -11,6 +11,7 @@ import net.minecraft.core.IRegistry;
 import net.minecraft.core.IRegistryCustom;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.resources.ResourceKey;
+import org.bukkit.Fluid;
 import org.bukkit.GameEvent;
 import org.bukkit.JukeboxSong;
 import org.bukkit.Keyed;
@@ -138,6 +139,9 @@ public class CraftRegistry<B extends Keyed, M> implements Registry<B> {
         if (bukkitClass == Enchantment.class) {
             return new CraftRegistry<>(Enchantment.class, registryHolder.lookupOrThrow(Registries.ENCHANTMENT), CraftEnchantment::new, FieldRename.ENCHANTMENT_RENAME);
         }
+        if (bukkitClass == Fluid.class) {
+            return new CraftRegistry<>(Fluid.class, registryHolder.lookupOrThrow(Registries.FLUID), CraftFluid::new, FieldRename.NONE);
+        }
         if (bukkitClass == GameEvent.class) {
             return new CraftRegistry<>(GameEvent.class, registryHolder.lookupOrThrow(Registries.GAME_EVENT), CraftGameEvent::new, FieldRename.NONE);
         }

paper-server/src/main/java/org/bukkit/craftbukkit/legacy/enums/EnumEvil.java

@@ -15,6 +15,7 @@ import java.util.Optional;
 import java.util.function.Function;
 import java.util.stream.Collector;
 import java.util.stream.Collectors;
+import org.bukkit.Fluid;
 import org.bukkit.NamespacedKey;
 import org.bukkit.Registry;
 import org.bukkit.attribute.Attribute;
@@ -46,6 +47,7 @@ public class EnumEvil {
     static {
         // Add Classes which got changed here
         REGISTRIES.put(Attribute.class, new LegacyRegistryData(Registry.ATTRIBUTE, Attribute::valueOf));
+        REGISTRIES.put(Fluid.class, new LegacyRegistryData(Registry.FLUID, Fluid::valueOf));
         REGISTRIES.put(Villager.Type.class, new LegacyRegistryData(Registry.VILLAGER_TYPE, Villager.Type::valueOf));
         REGISTRIES.put(Villager.Profession.class, new LegacyRegistryData(Registry.VILLAGER_PROFESSION, Villager.Profession::valueOf));
         REGISTRIES.put(Frog.Variant.class, new LegacyRegistryData(Registry.FROG_VARIANT, Frog.Variant::valueOf));

paper-server/src/main/java/org/bukkit/craftbukkit/util/Commodore.java

@@ -88,7 +88,8 @@ public class Commodore {
             "org/bukkit/entity/Cat$Type", "NOP",
             "org/bukkit/map/MapCursor$Type", "NOP",
             "org/bukkit/block/banner/PatternType", "NOP",
-            "org/bukkit/attribute/Attribute", "NOP"
+            "org/bukkit/attribute/Attribute", "NOP",
+            "org/bukkit/Fluid", "NOP"
     );
 
     private final List<Reroute> reroutes = new ArrayList<>(); // only for testing

paper-server/src/test/java/org/bukkit/support/provider/RegistriesArgumentProvider.java

@@ -15,13 +15,16 @@ import net.minecraft.world.entity.npc.VillagerType;
 import net.minecraft.world.inventory.Containers;
 import net.minecraft.world.item.Instrument;
 import net.minecraft.world.level.block.entity.EnumBannerPatternType;
+import net.minecraft.world.level.material.FluidType;
 import net.minecraft.world.level.saveddata.maps.MapDecorationType;
+import org.bukkit.Fluid;
 import org.bukkit.GameEvent;
 import org.bukkit.JukeboxSong;
 import org.bukkit.MusicInstrument;
 import org.bukkit.attribute.Attribute;
 import org.bukkit.block.BlockType;
 import org.bukkit.block.banner.PatternType;
+import org.bukkit.craftbukkit.CraftFluid;
 import org.bukkit.craftbukkit.CraftGameEvent;
 import org.bukkit.craftbukkit.CraftJukeboxSong;
 import org.bukkit.craftbukkit.CraftMusicInstrument;
@@ -68,6 +71,7 @@ public class RegistriesArgumentProvider implements ArgumentsProvider {
         // Order: Bukkit class, Minecraft Registry key, CraftBukkit class, Minecraft class
         register(Attribute.class, Registries.ATTRIBUTE, CraftAttribute.class, AttributeBase.class);
         register(Enchantment.class, Registries.ENCHANTMENT, CraftEnchantment.class, net.minecraft.world.item.enchantment.Enchantment.class);
+        register(Fluid.class, Registries.FLUID, CraftFluid.class, FluidType.class);
         register(GameEvent.class, Registries.GAME_EVENT, CraftGameEvent.class, net.minecraft.world.level.gameevent.GameEvent.class);
         register(MusicInstrument.class, Registries.INSTRUMENT, CraftMusicInstrument.class, Instrument.class);
         register(MenuType.class, Registries.MENU, CraftMenuType.class, Containers.class);