Complete Age lifecycle management (#8)

src/main/java/net/dnorberg/rivencraft/Rivencraft.java

@@ -10,6 +10,8 @@ import net.dnorberg.rivencraft.registry.ModBlockEntities;
 import net.dnorberg.rivencraft.registry.ModBiomeSources;
 import net.dnorberg.rivencraft.event.BookStandConversionHandler;
 import net.dnorberg.rivencraft.event.AgeCelestialAngleSync;
+import net.dnorberg.rivencraft.event.AgeLifecycleEvents;
+import net.dnorberg.rivencraft.command.RivencraftCommands;
 import net.dnorberg.rivencraft.network.ModNetworking;
 import net.dnorberg.rivencraft.config.RivencraftConfig;
 import net.dnorberg.rivencraft.config.RivencraftClientConfig;
@@ -43,6 +45,9 @@ public final class Rivencraft {
         NeoForge.EVENT_BUS.addListener(AgeWeatherService::onLevelTickPost);
         NeoForge.EVENT_BUS.addListener(AgeCelestialAngleSync::onPlayerLoggedIn);
         NeoForge.EVENT_BUS.addListener(AgeCelestialAngleSync::onPlayerChangedDimension);
+        NeoForge.EVENT_BUS.addListener(AgeLifecycleEvents::onPlayerLoggedOut);
+        NeoForge.EVENT_BUS.addListener(AgeLifecycleEvents::onServerStopping);
+        NeoForge.EVENT_BUS.addListener(RivencraftCommands::register);
         LOGGER.info("Initializing Rivencraft");
     }
 }

src/main/java/net/dnorberg/rivencraft/book/AgeDimensionService.java

@@ -1,6 +1,8 @@
 package net.dnorberg.rivencraft.book;
 
 import dev.galacticraft.dynamicdimensions.api.DynamicDimensionRegistry;
+import dev.galacticraft.dynamicdimensions.api.PlayerRemover;
+import dev.galacticraft.dynamicdimensions.api.event.DimensionRemovedCallback;
 import dev.galacticraft.dynamicdimensions.api.event.DynamicDimensionLoadCallback;
 import java.util.Optional;
 import java.util.OptionalLong;
@@ -56,6 +58,7 @@ public final class AgeDimensionService {
     }
 
     public static void register() {
+        DimensionRemovedCallback.register((dimension, level) -> synchronizeImmersivePortals(level.getServer()));
         DynamicDimensionLoadCallback.register((server, loader) -> {
             ServerLevel overworld = server.overworld();
             for (AgeDefinition age : AgeRegistrySavedData.get(overworld).definitions()) {
@@ -115,6 +118,27 @@ public final class AgeDimensionService {
         return loaded;
     }
 
+    /**
+     * Unloads an Age while retaining its saved definition and dimension data.
+     * A later book access reconstructs the same runtime level from that data.
+     */
+    public static UnloadResult unload(MinecraftServer server, AgeDefinition definition) {
+        ResourceKey<Level> key = dimensionKey(definition);
+        if (server.getLevel(key) == null) {
+            return UnloadResult.ALREADY_UNLOADED;
+        }
+
+        if (ModList.get().isLoaded("immersive_portals_core")) {
+            ImmersivePortalsChunkLoaders.closeForDimension(key);
+        }
+        boolean unloaded = DynamicDimensionRegistry.from(server)
+                .unloadDynamicDimension(definition.dimensionId(), PlayerRemover.DEFAULT);
+        if (!unloaded) {
+            return UnloadResult.FAILED;
+        }
+        return UnloadResult.UNLOADED;
+    }
+
     private static void applyCelestialClock(ServerLevel level, AgeDefinition age) {
         if (age.traits().hasStoppedCelestialCycle()) {
             // NeoForge rejects an exact zero rate. The smallest positive float
@@ -396,4 +420,10 @@ public final class AgeDimensionService {
         );
     }
 
+    public enum UnloadResult {
+        UNLOADED,
+        ALREADY_UNLOADED,
+        FAILED
+    }
+
 }

src/main/java/net/dnorberg/rivencraft/book/LinkingService.java

@@ -76,6 +76,7 @@ public final class LinkingService {
             LinkTarget target
     ) {
         if (ModList.get().isLoaded("immersive_portals_core")) {
+            ImmersivePortalsChunkLoaders.close(player);
             ImmersivePortalsChunkLoaders.teleport(
                     player, destinationLevel, position, target.yaw(), target.pitch());
         } else {

src/main/java/net/dnorberg/rivencraft/command/RivencraftCommands.java

@@ -0,0 +1,81 @@
+package net.dnorberg.rivencraft.command;
+
+import com.mojang.brigadier.arguments.StringArgumentType;
+import net.dnorberg.rivencraft.book.AgeDefinition;
+import net.dnorberg.rivencraft.book.AgeDimensionService;
+import net.dnorberg.rivencraft.book.AgeRegistrySavedData;
+import net.minecraft.commands.Commands;
+import net.minecraft.network.chat.Component;
+import net.minecraft.resources.ResourceLocation;
+import net.neoforged.neoforge.event.RegisterCommandsEvent;
+
+/** Administrative commands for inspecting and safely unloading persistent Ages. */
+public final class RivencraftCommands {
+    private RivencraftCommands() {
+    }
+
+    public static void register(RegisterCommandsEvent event) {
+        event.getDispatcher().register(Commands.literal("rivencraft")
+                .requires(source -> source.hasPermission(2))
+                .then(Commands.literal("age")
+                        .then(Commands.literal("list")
+                                .executes(context -> listAges(context.getSource())))
+                        .then(Commands.literal("unload")
+                                .then(Commands.argument("dimension", StringArgumentType.string())
+                                        .suggests((context, builder) -> {
+                                            AgeRegistrySavedData.get(context.getSource().getLevel()).definitions()
+                                                    .forEach(age -> builder.suggest(age.dimensionId().toString()));
+                                            return builder.buildFuture();
+                                        })
+                                        .executes(context -> unloadAge(
+                                                context.getSource(),
+                                                StringArgumentType.getString(context, "dimension")
+                                        ))))));
+    }
+
+    private static int listAges(net.minecraft.commands.CommandSourceStack source) {
+        var ages = AgeRegistrySavedData.get(source.getLevel()).definitions().stream()
+                .sorted(java.util.Comparator.comparing(AgeDefinition::name))
+                .toList();
+        source.sendSuccess(() -> Component.literal("Rivencraft Ages: " + ages.size()), false);
+        for (AgeDefinition age : ages) {
+            boolean loaded = source.getServer().getLevel(AgeDimensionService.dimensionKey(age)) != null;
+            source.sendSuccess(() -> Component.literal(
+                    (loaded ? "[loaded] " : "[unloaded] ")
+                            + age.name() + " — " + age.dimensionId()
+            ), false);
+        }
+        return ages.size();
+    }
+
+    private static int unloadAge(net.minecraft.commands.CommandSourceStack source, String requestedDimension) {
+        ResourceLocation dimension = ResourceLocation.tryParse(requestedDimension);
+        if (dimension == null) {
+            source.sendFailure(Component.literal("Invalid dimension id: " + requestedDimension));
+            return 0;
+        }
+        AgeDefinition age = AgeRegistrySavedData.get(source.getLevel()).findByDimension(dimension).orElse(null);
+        if (age == null) {
+            source.sendFailure(Component.literal("Unknown Rivencraft Age: " + dimension));
+            return 0;
+        }
+
+        AgeDimensionService.UnloadResult result = AgeDimensionService.unload(source.getServer(), age);
+        return switch (result) {
+            case UNLOADED -> {
+                source.sendSuccess(() -> Component.literal(
+                        "Unloaded " + age.name() + ". Its definition and world data were retained."
+                ), true);
+                yield 1;
+            }
+            case ALREADY_UNLOADED -> {
+                source.sendFailure(Component.literal(age.name() + " is already unloaded."));
+                yield 0;
+            }
+            case FAILED -> {
+                source.sendFailure(Component.literal("Dynamic Dimensions refused to unload " + age.name() + "."));
+                yield 0;
+            }
+        };
+    }
+}

src/main/java/net/dnorberg/rivencraft/compat/ImmersivePortalsChunkLoaders.java

@@ -1,11 +1,13 @@
 package net.dnorberg.rivencraft.compat;
 
+import java.util.IdentityHashMap;
 import java.util.Map;
-import java.util.WeakHashMap;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.server.level.ServerLevel;
+import net.minecraft.resources.ResourceKey;
+import net.minecraft.world.level.Level;
 import net.minecraft.world.phys.Vec3;
 import qouteall.imm_ptl.core.api.PortalAPI;
 import qouteall.imm_ptl.core.chunk_loading.ChunkLoader;
@@ -14,12 +16,12 @@ import qouteall.q_misc_util.dimension.DimensionIntId;
 
 /** Isolated server bridge; this class is loaded only when Immersive Portals is installed. */
 public final class ImmersivePortalsChunkLoaders {
-    private static final Map<ServerPlayer, ChunkLoader> LOADERS = new WeakHashMap<>();
+    private static final Map<ServerPlayer, ChunkLoader> LOADERS = new IdentityHashMap<>();
 
     private ImmersivePortalsChunkLoaders() {
     }
 
-    public static void open(ServerPlayer player, ServerLevel level, BlockPos center) {
+    public static synchronized void open(ServerPlayer player, ServerLevel level, BlockPos center) {
         close(player);
         int centerChunkX = center.getX() >> 4;
         int centerChunkZ = center.getZ() >> 4;
@@ -37,13 +39,28 @@ public final class ImmersivePortalsChunkLoaders {
         ImmPtlChunkTracking.immediatelyUpdateForPlayer(player);
     }
 
-    public static void close(ServerPlayer player) {
+    public static synchronized void close(ServerPlayer player) {
         ChunkLoader loader = LOADERS.remove(player);
         if (loader != null) {
             PortalAPI.removeChunkLoaderForPlayer(player, loader);
         }
     }
 
+    public static synchronized void closeForDimension(ResourceKey<Level> dimension) {
+        LOADERS.entrySet().removeIf(entry -> {
+            if (!entry.getValue().dimension().equals(dimension)) {
+                return false;
+            }
+            PortalAPI.removeChunkLoaderForPlayer(entry.getKey(), entry.getValue());
+            return true;
+        });
+    }
+
+    public static synchronized void closeAll() {
+        LOADERS.forEach(PortalAPI::removeChunkLoaderForPlayer);
+        LOADERS.clear();
+    }
+
     /** Registers runtime dimensions and sends the revised ID map to connected clients. */
     public static void dimensionsChanged(MinecraftServer server) {
         DimensionIntId.onServerDimensionChanged(server);

src/main/java/net/dnorberg/rivencraft/event/AgeLifecycleEvents.java

@@ -0,0 +1,26 @@
+package net.dnorberg.rivencraft.event;
+
+import net.dnorberg.rivencraft.compat.ImmersivePortalsChunkLoaders;
+import net.minecraft.server.level.ServerPlayer;
+import net.neoforged.fml.ModList;
+import net.neoforged.neoforge.event.entity.player.PlayerEvent;
+import net.neoforged.neoforge.event.server.ServerStoppingEvent;
+
+/** Server-authoritative cleanup for resources that exist only while a preview is active. */
+public final class AgeLifecycleEvents {
+    private AgeLifecycleEvents() {
+    }
+
+    public static void onPlayerLoggedOut(PlayerEvent.PlayerLoggedOutEvent event) {
+        if (event.getEntity() instanceof ServerPlayer player
+                && ModList.get().isLoaded("immersive_portals_core")) {
+            ImmersivePortalsChunkLoaders.close(player);
+        }
+    }
+
+    public static void onServerStopping(ServerStoppingEvent event) {
+        if (ModList.get().isLoaded("immersive_portals_core")) {
+            ImmersivePortalsChunkLoaders.closeAll();
+        }
+    }
+}

src/main/java/net/dnorberg/rivencraft/gametest/LinkingGameTests.java

@@ -152,6 +152,42 @@ public final class LinkingGameTests {
         });
     }
 
+    @GameTest(template = "empty", timeoutTicks = 100)
+    public static void unloadedAgeReloadsWithTheSameDefinition(GameTestHelper helper) {
+        UUID id = UUID.randomUUID();
+        AgeDefinition definition = AgeRegistrySavedData.resolveOrCreate(
+                helper.getLevel(),
+                new AgeReference(id, "Lifecycle Test Age " + id)
+        );
+
+        var server = helper.getLevel().getServer();
+        var first = AgeDimensionService.ensureLoaded(server, definition);
+        helper.assertTrue(first != null, "The lifecycle test Age must load");
+        helper.runAfterDelay(1, () -> {
+            helper.assertValueEqual(
+                    AgeDimensionService.unload(server, definition),
+                    AgeDimensionService.UnloadResult.UNLOADED,
+                    "A loaded Age must unload without deleting its definition"
+            );
+            helper.runAfterDelay(1, () -> {
+                helper.assertTrue(server.getLevel(AgeDimensionService.dimensionKey(definition)) == null,
+                        "An unloaded Age must leave the active server level map");
+
+                var reloaded = AgeDimensionService.ensureLoaded(server, definition);
+                helper.assertTrue(reloaded != null, "A book must be able to reload an archived Age");
+                helper.runAfterDelay(1, () -> {
+                    var registered = server.getLevel(AgeDimensionService.dimensionKey(definition));
+                    helper.assertTrue(registered != null, "The reloaded Age must rejoin the active server level map");
+                    helper.assertValueEqual(registered.getSeed(), definition.seed(),
+                            "Reloading an Age must preserve its immutable seed");
+                    helper.assertValueEqual(registered.dimension().location(), definition.dimensionId(),
+                            "Reloading an Age must preserve its dimension identifier");
+                    helper.succeed();
+                });
+            });
+        });
+    }
+
     @GameTest(template = "empty", timeoutTicks = 200)
     public static void legacyBaseTerrainProfilesLoadRuntimeDimensions(GameTestHelper helper) {
         for (var profile : AgeGenerationProfiles.all()) {