From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: dfsek <dfsek@protonmail.com>
Date: Wed, 16 Sep 2020 01:12:29 -0700
Subject: [PATCH] Add StructuresLocateEvent

Co-authored-by: Jake Potrebic <jake.m.potrebic@gmail.com>

diff --git a/src/main/java/io/papermc/paper/registry/PaperRegistries.java b/src/main/java/io/papermc/paper/registry/PaperRegistries.java
index cc7d4924098eab9663cc52917e4b30d6ef4b02c7..183e168afcc4302bc1e3274a89835f1f60e4bbd6 100644
--- a/src/main/java/io/papermc/paper/registry/PaperRegistries.java
+++ b/src/main/java/io/papermc/paper/registry/PaperRegistries.java
@@ -40,6 +40,12 @@ import static io.papermc.paper.registry.entry.RegistryEntry.entry;
 @DefaultQualifier(NonNull.class)
 public final class PaperRegistries {
 
+    @Deprecated(forRemoval = true)
+    @org.jetbrains.annotations.VisibleForTesting
+    public static final RegistryKey<io.papermc.paper.world.structure.ConfiguredStructure> CONFIGURED_STRUCTURE_REGISTRY_KEY = RegistryKeyImpl.createInternal("worldgen/structure");
+    @Deprecated(forRemoval = true)
+    static final RegistryEntry<Structure, io.papermc.paper.world.structure.ConfiguredStructure, ?> CONFIGURED_STRUCTURE_REGISTRY_ENTRY = entry(Registries.STRUCTURE, CONFIGURED_STRUCTURE_REGISTRY_KEY, io.papermc.paper.world.structure.ConfiguredStructure.class, io.papermc.paper.world.structure.PaperConfiguredStructure::minecraftToBukkit).delayed();
+
     static final List<RegistryEntry<?, ?, ?>> REGISTRY_ENTRIES;
     private static final Map<RegistryKey<?>, RegistryEntry<?, ?, ?>> BY_REGISTRY_KEY;
     private static final Map<ResourceKey<?>, RegistryEntry<?, ?, ?>> BY_RESOURCE_KEY;
diff --git a/src/main/java/io/papermc/paper/registry/PaperRegistryAccess.java b/src/main/java/io/papermc/paper/registry/PaperRegistryAccess.java
index 9f2bcfe0d9e479466a1e46e503071d1151310e6a..7aa1a29e93b787e1167169bc7d6e9563daf6241e 100644
--- a/src/main/java/io/papermc/paper/registry/PaperRegistryAccess.java
+++ b/src/main/java/io/papermc/paper/registry/PaperRegistryAccess.java
@@ -45,8 +45,13 @@ public class PaperRegistryAccess implements RegistryAccess {
     public <T extends Keyed> @Nullable Registry<T> getRegistry(final Class<T> type) {
         final RegistryKey<T> registryKey;
         final @Nullable RegistryEntry<?, T, ?> entry;
-        registryKey = requireNonNull(byType(type), () -> type + " is not a valid registry type");
-        entry = PaperRegistries.getEntry(registryKey);
+        if (type == io.papermc.paper.world.structure.ConfiguredStructure.class) { // manually handle "duplicate" registries to avoid polluting maps in PaperRegistries
+            registryKey = (RegistryKey<T>) PaperRegistries.CONFIGURED_STRUCTURE_REGISTRY_KEY;
+            entry = (RegistryEntry<?, T, ?>) PaperRegistries.CONFIGURED_STRUCTURE_REGISTRY_ENTRY;
+        } else {
+            registryKey = requireNonNull(byType(type), () -> type + " is not a valid registry type");
+            entry = PaperRegistries.getEntry(registryKey);
+        }
         final @Nullable RegistryHolder<T> registry = (RegistryHolder<T>) this.registries.get(registryKey);
         if (registry != null) {
             // if the registry exists, return right away. Since this is the "legacy" method, we return DelayedRegistry
diff --git a/src/main/java/io/papermc/paper/world/structure/PaperConfiguredStructure.java b/src/main/java/io/papermc/paper/world/structure/PaperConfiguredStructure.java
new file mode 100644
index 0000000000000000000000000000000000000000..013d614a1cf1ab2b5a6ec190c2b4ba7753268731
--- /dev/null
+++ b/src/main/java/io/papermc/paper/world/structure/PaperConfiguredStructure.java
@@ -0,0 +1,27 @@
+package io.papermc.paper.world.structure;
+
+import java.util.Objects;
+import net.minecraft.core.Registry;
+import net.minecraft.core.registries.BuiltInRegistries;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.level.levelgen.structure.Structure;
+import org.bukkit.NamespacedKey;
+import org.bukkit.StructureType;
+import org.bukkit.craftbukkit.CraftRegistry;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+@DefaultQualifier(NonNull.class)
+@Deprecated(forRemoval = true)
+public final class PaperConfiguredStructure {
+
+    private PaperConfiguredStructure() {
+    }
+
+    public static @Nullable ConfiguredStructure minecraftToBukkit(NamespacedKey key, Structure nms) {
+        final ResourceLocation structureTypeLoc = Objects.requireNonNull(BuiltInRegistries.STRUCTURE_TYPE.getKey(nms.type()), "unexpected structure type " + nms.type());
+        final @Nullable StructureType structureType = StructureType.getStructureTypes().get(structureTypeLoc.getPath());
+        return structureType == null ? null : new ConfiguredStructure(key, structureType);
+    }
+}
diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
index 7cdb59cd2f2ffe1195d21519ef97dae0e430285b..a8768f1925d5824ca985be1b53694ee233273758 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
@@ -127,6 +127,24 @@ public abstract class ChunkGenerator {
 
     @Nullable
     public Pair<BlockPos, Holder<Structure>> findNearestMapStructure(ServerLevel world, HolderSet<Structure> structures, BlockPos center, int radius, boolean skipReferencedStructures) {
+        // Paper start - StructuresLocateEvent
+        final org.bukkit.World bukkitWorld = world.getWorld();
+        final org.bukkit.Location origin = io.papermc.paper.util.MCUtil.toLocation(world, center);
+        final List<org.bukkit.generator.structure.Structure> apiStructures = structures.stream().map(Holder::value).map(nms -> org.bukkit.craftbukkit.generator.structure.CraftStructure.minecraftToBukkit(nms)).toList();
+        if (!apiStructures.isEmpty()) {
+            final io.papermc.paper.event.world.StructuresLocateEvent event = new io.papermc.paper.event.world.StructuresLocateEvent(bukkitWorld, origin, apiStructures, radius, skipReferencedStructures);
+            if (!event.callEvent()) {
+                return null;
+            }
+            if (event.getResult() != null) {
+                return Pair.of(io.papermc.paper.util.MCUtil.toBlockPos(event.getResult().pos()), world.registryAccess().registryOrThrow(Registries.STRUCTURE).wrapAsHolder(org.bukkit.craftbukkit.generator.structure.CraftStructure.bukkitToMinecraft(event.getResult().structure())));
+            }
+            center = io.papermc.paper.util.MCUtil.toBlockPosition(event.getOrigin());
+            radius = event.getRadius();
+            skipReferencedStructures = event.shouldFindUnexplored();
+            structures = HolderSet.direct(api -> world.registryAccess().registryOrThrow(Registries.STRUCTURE).wrapAsHolder(org.bukkit.craftbukkit.generator.structure.CraftStructure.bukkitToMinecraft(api)), event.getStructures());
+        }
+        // Paper end
         ChunkGeneratorStructureState chunkgeneratorstructurestate = world.getChunkSource().getGeneratorState();
         Map<StructurePlacement, Set<Holder<Structure>>> map = new Object2ObjectArrayMap();
         Iterator iterator = structures.iterator();
diff --git a/src/test/java/io/papermc/paper/world/structure/ConfiguredStructureTest.java b/src/test/java/io/papermc/paper/world/structure/ConfiguredStructureTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..9178fe0d01b998ca1442bf2511f8fc00db9388ba
--- /dev/null
+++ b/src/test/java/io/papermc/paper/world/structure/ConfiguredStructureTest.java
@@ -0,0 +1,96 @@
+package io.papermc.paper.world.structure;
+
+import io.papermc.paper.registry.Reference;
+import net.minecraft.core.Registry;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.resources.ResourceKey;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.Bootstrap;
+import net.minecraft.world.level.levelgen.structure.Structure;
+import net.minecraft.world.level.levelgen.structure.BuiltinStructures;
+import org.bukkit.NamespacedKey;
+import org.bukkit.craftbukkit.util.CraftNamespacedKey;
+import org.bukkit.support.AbstractTestingBase;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.io.PrintStream;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.StringJoiner;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+@Deprecated(forRemoval = true)
+public class ConfiguredStructureTest extends AbstractTestingBase {
+
+    private static final Map<ResourceLocation, String> BUILT_IN_STRUCTURES = new LinkedHashMap<>();
+    private static final Map<NamespacedKey, Reference<?>> DEFAULT_CONFIGURED_STRUCTURES = new LinkedHashMap<>();
+
+    private static PrintStream out;
+
+    @BeforeAll
+    public static void collectStructures() throws ReflectiveOperationException {
+        out = System.out;
+        System.setOut(Bootstrap.STDOUT);
+        for (Field field : BuiltinStructures.class.getDeclaredFields()) {
+            if (field.getType().equals(ResourceKey.class) && Modifier.isStatic(field.getModifiers())) {
+                BUILT_IN_STRUCTURES.put(((ResourceKey<?>) field.get(null)).location(), field.getName());
+            }
+        }
+        for (Field field : ConfiguredStructure.class.getDeclaredFields()) {
+            if (field.getType().equals(Reference.class) && Modifier.isStatic(field.getModifiers())) {
+                final Reference<?> ref = (Reference<?>) field.get(null);
+                DEFAULT_CONFIGURED_STRUCTURES.put(ref.getKey(), ref);
+            }
+        }
+    }
+
+    @Test
+    public void testMinecraftToApi() {
+        Registry<Structure> structureRegistry = AbstractTestingBase.REGISTRY_CUSTOM.registryOrThrow(Registries.STRUCTURE);
+        assertEquals(BUILT_IN_STRUCTURES.size(), structureRegistry.size(), "configured structure maps should be the same size");
+
+        Map<ResourceLocation, Structure> missing = new LinkedHashMap<>();
+        for (Structure feature : structureRegistry) {
+            final ResourceLocation key = structureRegistry.getKey(feature);
+            assertNotNull(key, "Missing built-in registry key");
+            if (key.equals(BuiltinStructures.ANCIENT_CITY.location()) || key.equals(BuiltinStructures.TRAIL_RUINS.location()) || key.equals(BuiltinStructures.TRIAL_CHAMBERS.location())) {
+                continue; // TODO remove when upstream adds "jigsaw" StructureType
+            }
+            if (DEFAULT_CONFIGURED_STRUCTURES.get(CraftNamespacedKey.fromMinecraft(key)) == null) {
+                missing.put(key, feature);
+            }
+        }
+
+        assertTrue(missing.isEmpty(), printMissing(missing));
+    }
+
+    @Test
+    public void testApiToMinecraft() {
+        Registry<Structure> structureRegistry = AbstractTestingBase.REGISTRY_CUSTOM.registryOrThrow(Registries.STRUCTURE);
+        for (NamespacedKey apiKey : DEFAULT_CONFIGURED_STRUCTURES.keySet()) {
+            assertTrue(structureRegistry.containsKey(CraftNamespacedKey.toMinecraft(apiKey)), apiKey + " does not have a minecraft counterpart");
+        }
+    }
+
+    private static String printMissing(Map<ResourceLocation, Structure> missing) {
+        final StringJoiner joiner = new StringJoiner("\n", "Missing: \n", "");
+
+        missing.forEach((key, configuredFeature) -> {
+            joiner.add("public static final Reference<ConfiguredStructure> " + BUILT_IN_STRUCTURES.get(key) + " = create(\"" + key.getPath() + "\");");
+        });
+
+        return joiner.toString();
+    }
+
+    @AfterAll
+    public static void after() {
+        System.setOut(out);
+    }
+}
diff --git a/src/test/java/org/bukkit/registry/PerRegistryTest.java b/src/test/java/org/bukkit/registry/PerRegistryTest.java
index 4e4ea083063daf22f1bb785ef212958ea889c43b..523b4b208e05c6b70014440200e3196cc84f36cc 100644
--- a/src/test/java/org/bukkit/registry/PerRegistryTest.java
+++ b/src/test/java/org/bukkit/registry/PerRegistryTest.java
@@ -36,6 +36,7 @@ public class PerRegistryTest extends AbstractTestingBase {
                 if (!(object instanceof CraftRegistry<?, ?> registry)) {
                     continue;
                 }
+                if (object == Registry.CONFIGURED_STRUCTURE) continue; // Paper - skip
 
                 data.add(Arguments.of(registry));
             } catch (ReflectiveOperationException e) {
diff --git a/src/test/java/org/bukkit/registry/RegistryArgumentAddedTest.java b/src/test/java/org/bukkit/registry/RegistryArgumentAddedTest.java
index 0dd775ad1bd0bf9ba7ea05255d543a9df8b5fcfd..c1e51d104c52dd3f3e48d651b0ff1f00ae9bf96d 100644
--- a/src/test/java/org/bukkit/registry/RegistryArgumentAddedTest.java
+++ b/src/test/java/org/bukkit/registry/RegistryArgumentAddedTest.java
@@ -26,6 +26,7 @@ public class RegistryArgumentAddedTest extends AbstractTestingBase {
         loadedRegistries.addAll(io.papermc.paper.registry.PaperRegistryAccess.instance().getLoadedServerBackedRegistries());
         // Paper end
         Set<io.papermc.paper.registry.RegistryKey<?>> notFound = new HashSet<>(); // Paper
+        loadedRegistries.remove(io.papermc.paper.registry.PaperRegistries.CONFIGURED_STRUCTURE_REGISTRY_KEY); // Paper - ignore
 
         RegistriesArgumentProvider
                 .getData()
