#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();
     }
 }