Fix village structure

src/generated/resources/.cache/1406a188eb544a1b57b1bc878397d8c7862b79de

@@ -0,0 +1 @@
+// 1.21.1	2024-10-22T19:46:05.5548254	Update structure files in /structure

src/main/java/de/ellpeck/actuallyadditions/data/ActuallyAdditionsData.java

@@ -1,5 +1,6 @@
 package de.ellpeck.actuallyadditions.data;
 
+import de.ellpeck.actuallyadditions.api.ActuallyAdditionsAPI;
 import de.ellpeck.actuallyadditions.data.patchouli.PatchouliGenerator;
 import de.ellpeck.actuallyadditions.mod.ActuallyAdditions;
 import de.ellpeck.actuallyadditions.mod.gen.ActuallyBiomeModifiers;
@@ -72,6 +73,7 @@ public class ActuallyAdditionsData {
 
         generator.addProvider(event.includeServer(), new DatapackBuiltinEntriesProvider(
                 packOutput, patchedProvider, Set.of(ActuallyAdditions.MODID)));
+        generator.addProvider(true, new StructureUpdater("structure", ActuallyAdditionsAPI.MOD_ID, helper, packOutput));
 
         generator.addProvider(true, new Curios(packOutput, helper, lookupProvider));
     }

src/main/java/de/ellpeck/actuallyadditions/data/StructureUpdater.java

@@ -0,0 +1,102 @@
+package de.ellpeck.actuallyadditions.data;
+
+/*
+ *  BluSunrize
+ *  Copyright (c) 2021
+ *
+ *  This code is licensed under "Blu's License of Common Sense".
+ *  Class written by malte0811 and BluSunrize, and used with malte's permission.
+ */
+
+import com.google.common.hash.Hashing;
+import com.mojang.datafixers.DataFixer;
+import com.mojang.datafixers.DataFixerUpper;
+import net.minecraft.core.registries.BuiltInRegistries;
+import net.minecraft.data.CachedOutput;
+import net.minecraft.data.DataProvider;
+import net.minecraft.data.PackOutput;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtAccounter;
+import net.minecraft.nbt.NbtIo;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.packs.resources.MultiPackResourceManager;
+import net.minecraft.server.packs.resources.Resource;
+import net.minecraft.util.datafix.DataFixTypes;
+import net.minecraft.util.datafix.DataFixers;
+import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplate;
+import net.neoforged.neoforge.common.data.ExistingFileHelper;
+
+import javax.annotation.Nonnull;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.nio.file.Path;
+import java.util.concurrent.CompletableFuture;
+
+public class StructureUpdater implements DataProvider {
+	private final String basePath;
+	private final String modid;
+	private final PackOutput output;
+	private final MultiPackResourceManager resources;
+
+	public StructureUpdater(
+			String basePath, String modid, ExistingFileHelper helper, PackOutput output
+	) {
+		this.basePath = basePath;
+		this.modid = modid;
+		this.output = output;
+		try {
+			Field serverData = ExistingFileHelper.class.getDeclaredField("serverData");
+			serverData.setAccessible(true);
+			resources = (MultiPackResourceManager) serverData.get(helper);
+		} catch (NoSuchFieldException | IllegalAccessException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	@Override
+	public CompletableFuture<?> run(@Nonnull CachedOutput cache) {
+		try {
+			for (var entry : resources.listResources(basePath, $ -> true).entrySet())
+				if (entry.getKey().getNamespace().equals(modid))
+					process(entry.getKey(), entry.getValue(), cache);
+			return CompletableFuture.completedFuture(null);
+		} catch (IOException x) {
+			return CompletableFuture.failedFuture(x);
+		}
+	}
+
+	private void process(ResourceLocation loc, Resource resource, CachedOutput cache) throws IOException {
+		CompoundTag inputNBT = NbtIo.readCompressed(resource.open(), NbtAccounter.unlimitedHeap());
+		CompoundTag converted = updateNBT(inputNBT);
+		if (!converted.equals(inputNBT)) {
+			Class<? extends DataFixer> fixerClass = DataFixers.getDataFixer().getClass();
+			if (!fixerClass.equals(DataFixerUpper.class))
+				throw new RuntimeException("Structures are not up to date, but unknown data fixer is in use: " + fixerClass.getName());
+			writeNBTTo(loc, converted, cache);
+		}
+	}
+
+	private void writeNBTTo(ResourceLocation loc, CompoundTag data, CachedOutput cache) throws IOException {
+		ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream();
+		NbtIo.writeCompressed(data, bytearrayoutputstream);
+		byte[] bytes = bytearrayoutputstream.toByteArray();
+		Path outputPath = output.getOutputFolder().resolve("data/" + loc.getNamespace() + "/" + loc.getPath());
+		cache.writeIfNeeded(outputPath, bytes, Hashing.sha1().hashBytes(bytes));
+	}
+
+	private static CompoundTag updateNBT(CompoundTag nbt) {
+		final CompoundTag updatedNBT = DataFixTypes.STRUCTURE.updateToCurrentVersion(
+				DataFixers.getDataFixer(), nbt, nbt.getInt("DataVersion")
+		);
+		StructureTemplate template = new StructureTemplate();
+		template.load(BuiltInRegistries.BLOCK.asLookup(), updatedNBT);
+		return template.save(new CompoundTag());
+	}
+
+	@Nonnull
+	@Override
+	public String getName() {
+		return "Update structure files in /" + basePath + "/";
+	}
+}