Give thread pools time to terminate & Save all data before shutting down

this should be configurable

scripts/proxy.py

@@ -68,7 +68,7 @@ class MlgmXyysd_Animation_Company_Proxy:
     ]
 
     def request(self, flow: http.HTTPFlow) -> None:
-        if flow.request.pretty_host in self.LIST_DOMAINS:
+        if flow.request.host in self.LIST_DOMAINS:
             if USE_SSL:
                 flow.request.scheme = "https"
             else:

src/main/java/emu/grasscutter/Grasscutter.java

@@ -1,8 +1,5 @@
 package emu.grasscutter;
 
-import static emu.grasscutter.config.Configuration.SERVER;
-import static emu.grasscutter.utils.lang.Language.translate;
-
 import ch.qos.logback.classic.*;
 import emu.grasscutter.auth.*;
 import emu.grasscutter.command.*;
@@ -21,16 +18,20 @@ import emu.grasscutter.tools.Tools;
 import emu.grasscutter.utils.*;
 import emu.grasscutter.utils.lang.Language;
 import io.netty.util.concurrent.FastThreadLocalThread;
-import java.io.*;
-import java.util.Calendar;
-import java.util.concurrent.*;
-import javax.annotation.Nullable;
 import lombok.*;
 import org.jline.reader.*;
 import org.jline.terminal.*;
 import org.reflections.Reflections;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nullable;
+import java.io.*;
+import java.util.Calendar;
+import java.util.concurrent.*;
+
+import static emu.grasscutter.config.Configuration.SERVER;
+import static emu.grasscutter.utils.lang.Language.translate;
+
 public final class Grasscutter {
     public static final File configFile = new File("./config.json");
     public static final Reflections reflector = new Reflections("emu.grasscutter");
@@ -158,8 +159,6 @@ public final class Grasscutter {
 
             // Generate handbooks.
             Tools.createGmHandbooks(false);
-            // Generate gacha mappings.
-            Tools.generateGachaMappings();
         }
 
         // Start servers.
@@ -183,12 +182,18 @@ public final class Grasscutter {
         // Hook into shutdown event.
         Runtime.getRuntime().addShutdownHook(new Thread(Grasscutter::onShutdown));
 
+        // Start database heartbeat.
+        Database.startSaveThread();
+
         // Open console.
         Grasscutter.startConsole();
     }
 
     /** Server shutdown event. */
     private static void onShutdown() {
+        // Save all data.
+        Database.saveAll();
+
         // Disable all plugins.
         if (pluginManager != null) pluginManager.disablePlugins();
         // Shutdown the game server.
@@ -198,14 +203,14 @@ public final class Grasscutter {
             // Wait for Grasscutter's thread pool to finish.
             var executor = Grasscutter.getThreadPool();
             executor.shutdown();
-            if (!executor.awaitTermination(5, TimeUnit.SECONDS)) {
+            if (!executor.awaitTermination(1, TimeUnit.MINUTES)) {
                 executor.shutdownNow();
             }
 
             // Wait for database operations to finish.
             var dbExecutor = DatabaseHelper.getEventExecutor();
             dbExecutor.shutdown();
-            if (!dbExecutor.awaitTermination(5, TimeUnit.SECONDS)) {
+            if (!dbExecutor.awaitTermination(2, TimeUnit.MINUTES)) {
                 dbExecutor.shutdownNow();
             }
         } catch (InterruptedException ignored) {

src/main/java/emu/grasscutter/command/CommandHelpers.java

@@ -1,6 +1,5 @@
 package emu.grasscutter.command;
 
-import emu.grasscutter.game.world.Position;
 import java.util.*;
 import java.util.function.BiConsumer;
 import java.util.regex.*;
@@ -55,78 +54,4 @@ public class CommandHelpers {
                 });
         return args;
     }
-
-    public static float parseRelative(String input, Float current) {
-        if (input.contains("~")) { // Relative
-            if (!input.equals("~")) { // Relative with offset
-                current += Float.parseFloat(input.replace("~", ""));
-            } // Else no offset, no modification
-        } else { // Absolute
-            current = Float.parseFloat(input);
-        }
-        return current;
-    }
-
-    public static Position parsePosition(
-            String inputX, String inputY, String inputZ, Position curPos, Position curRot) {
-        Position offset = new Position();
-        Position target = new Position(curPos);
-        if (inputX.contains("~")) { // Relative
-            if (!inputX.equals("~")) { // Relative with offset
-                target.addX(Float.parseFloat(inputX.replace("~", "")));
-            }
-        } else if (inputX.contains("^")) {
-            if (!inputX.equals("^")) {
-                offset.setX(Float.parseFloat(inputX.replace("^", "")));
-            }
-        } else { // Absolute
-            target.setX(Float.parseFloat(inputX));
-        }
-
-        if (inputY.contains("~")) { // Relative
-            if (!inputY.equals("~")) { // Relative with offset
-                target.addY(Float.parseFloat(inputY.replace("~", "")));
-            }
-        } else if (inputY.contains("^")) {
-            if (!inputY.equals("^")) {
-                offset.setY(Float.parseFloat(inputY.replace("^", "")));
-            }
-        } else { // Absolute
-            target.setY(Float.parseFloat(inputY));
-        }
-
-        if (inputZ.contains("~")) { // Relative
-            if (!inputZ.equals("~")) { // Relative with offset
-                target.addZ(Float.parseFloat(inputZ.replace("~", "")));
-            }
-        } else if (inputZ.contains("^")) {
-            if (!inputZ.equals("^")) {
-                offset.setZ(Float.parseFloat(inputZ.replace("^", "")));
-            }
-        } else { // Absolute
-            target.setZ(Float.parseFloat(inputZ));
-        }
-
-        if (!offset.equal3d(Position.ZERO)) {
-            return calculateOffset(target, curRot, offset);
-        } else {
-            return target;
-        }
-    }
-
-    public static Position calculateOffset(Position pos, Position rot, Position offset) {
-        // Degrees to radians
-        float angleZ = (float) Math.toRadians(rot.getY());
-        float angleX = (float) Math.toRadians(rot.getY() + 90);
-
-        // Calculate offset based on current position and rotation
-        return new Position(
-                pos.getX()
-                        + offset.getZ() * (float) Math.sin(angleZ)
-                        + offset.getX() * (float) Math.sin(angleX),
-                pos.getY() + offset.getY(),
-                pos.getZ()
-                        + offset.getZ() * (float) Math.cos(angleZ)
-                        + offset.getX() * (float) Math.cos(angleX));
-    }
 }

src/main/java/emu/grasscutter/command/commands/SpawnCommand.java

@@ -21,9 +21,9 @@ import lombok.Setter;
         label = "spawn",
         aliases = {"drop", "s"},
         usage = {
-            "<itemId> [x<amount>] [blk<blockId>] [grp<groupId>] [cfg<configId>] [<x> <y> <z>] [<rotX> <rotY> <rotZ>]",
+            "<itemId> [x<amount>] [blk<blockId>] [grp<groupId>] [cfg<configId>] <x> <y> <z>",
-            "<gadgetId> [x<amount>] [state<state>] [maxhp<maxhp>] [hp<hp>(0 for infinite)] [atk<atk>] [def<def>] [blk<blockId>] [grp<groupId>] [cfg<configId>] [<x> <y> <z>] [<rotX> <rotY> <rotZ>]",
+            "<gadgetId> [x<amount>] [state<state>] [maxhp<maxhp>] [hp<hp>(0 for infinite)] [atk<atk>] [def<def>] [blk<blockId>] [grp<groupId>] [cfg<configId>] <x> <y> <z>",
-            "<monsterId> [x<amount>] [lv<level>] [ai<aiId>] [maxhp<maxhp>] [hp<hp>(0 for infinite)] [atk<atk>] [def<def>] [blk<blockId>] [grp<groupId>] [cfg<configId>] [<x> <y> <z>] [<rotX> <rotY> <rotZ>]"
+            "<monsterId> [x<amount>] [lv<level>] [ai<aiId>] [maxhp<maxhp>] [hp<hp>(0 for infinite)] [atk<atk>] [def<def>] [blk<blockId>] [grp<groupId>] [cfg<configId>] <x> <y> <z>"
         },
         permission = "server.spawn",
         permissionTargeted = "server.spawn.others")
@@ -53,23 +53,14 @@ public final class SpawnCommand implements CommandHandler {
             sendUsageMessage(sender); // Reachable if someone does `/give lv90` or similar
             throw new IllegalArgumentException();
         }
-
-        Position pos = new Position(targetPlayer.getPosition());
-        Position rot = new Position(targetPlayer.getRotation());
-
         switch (args.size()) {
-            case 7:
-                try {
-                    rot.setX(CommandHelpers.parseRelative(args.get(4), rot.getX()));
-                    rot.setY(CommandHelpers.parseRelative(args.get(5), rot.getY()));
-                    rot.setZ(CommandHelpers.parseRelative(args.get(6), rot.getZ()));
-                } catch (NumberFormatException ignored) {
-                    CommandHandler.sendMessage(
-                            sender, translate(sender, "commands.execution.argument_error"));
-                } // Fallthrough
             case 4:
                 try {
-                    pos = CommandHelpers.parsePosition(args.get(1), args.get(2), args.get(3), pos, rot);
+                    float x, y, z;
+                    x = Float.parseFloat(args.get(1));
+                    y = Float.parseFloat(args.get(2));
+                    z = Float.parseFloat(args.get(3));
+                    param.pos = new Position(x, y, z);
                 } catch (NumberFormatException ignored) {
                     CommandHandler.sendMessage(
                             sender, translate(sender, "commands.execution.argument_error"));
@@ -86,8 +77,6 @@ public final class SpawnCommand implements CommandHandler {
                 sendUsageMessage(sender);
                 return;
         }
-        param.pos = pos;
-        param.rot = rot;
 
         MonsterData monsterData = GameData.getMonsterDataMap().get(param.id);
         GadgetData gadgetData = GameData.getGadgetDataMap().get(param.id);
@@ -113,8 +102,12 @@ public final class SpawnCommand implements CommandHandler {
         }
 
         double maxRadius = Math.sqrt(param.amount * 0.2 / Math.PI);
+        if (param.pos == null) {
+            param.pos = targetPlayer.getPosition();
+        }
+
         for (int i = 0; i < param.amount; i++) {
-            pos = GetRandomPositionInCircle(param.pos, maxRadius).addY(3);
+            Position pos = GetRandomPositionInCircle(param.pos, maxRadius).addY(3);
             GameEntity entity = null;
             if (itemData != null) {
                 entity = createItem(itemData, param, pos);
@@ -135,12 +128,12 @@ public final class SpawnCommand implements CommandHandler {
     }
 
     private EntityItem createItem(ItemData itemData, SpawnParameters param, Position pos) {
-        return new EntityItem(param.scene, null, itemData, pos, param.rot, 1, true);
+        return new EntityItem(param.scene, null, itemData, pos, 1, true);
     }
 
     private EntityMonster createMonster(
             MonsterData monsterData, SpawnParameters param, Position pos) {
-        var entity = new EntityMonster(param.scene, monsterData, pos, param.rot, param.lvl);
+        var entity = new EntityMonster(param.scene, monsterData, pos, param.lvl);
         if (param.ai != -1) {
             entity.setAiId(param.ai);
         }
@@ -151,13 +144,16 @@ public final class SpawnCommand implements CommandHandler {
             GadgetData gadgetData, SpawnParameters param, Position pos, Player targetPlayer) {
         EntityBaseGadget entity;
         if (gadgetData.getType() == EntityType.Vehicle) {
-            entity = new EntityVehicle(param.scene, targetPlayer, param.id, 0, pos, param.rot);
+            entity =
+                    new EntityVehicle(
+                            param.scene, targetPlayer, param.id, 0, pos, targetPlayer.getRotation());
         } else {
-            entity = new EntityGadget(param.scene, param.id, pos, param.rot);
+            entity = new EntityGadget(param.scene, param.id, pos, targetPlayer.getRotation());
             if (param.state != -1) {
                 ((EntityGadget) entity).setState(param.state);
             }
         }
+
         return entity;
     }
 
@@ -211,7 +207,6 @@ public final class SpawnCommand implements CommandHandler {
         @Setter public int def = -1;
         @Setter public int ai = -1;
         @Setter public Position pos = null;
-        @Setter public Position rot = null;
         public Scene scene = null;
     }
 }

src/main/java/emu/grasscutter/command/commands/TeleportCommand.java

@@ -16,10 +16,24 @@ import java.util.List;
         permissionTargeted = "player.teleport.others")
 public final class TeleportCommand implements CommandHandler {
 
+    private float parseRelative(
+            String input, Float current) { // TODO: Maybe this will be useful elsewhere later
+        if (input.contains("~")) { // Relative
+            if (!input.equals("~")) { // Relative with offset
+                current += Float.parseFloat(input.replace("~", ""));
+            } // Else no offset, no modification
+        } else { // Absolute
+            current = Float.parseFloat(input);
+        }
+        return current;
+    }
+
     @Override
     public void execute(Player sender, Player targetPlayer, List<String> args) {
-        Position pos = new Position(targetPlayer.getPosition());
+        Position pos = targetPlayer.getPosition();
-        Position rot = new Position(targetPlayer.getRotation());
+        float x = pos.getX();
+        float y = pos.getY();
+        float z = pos.getZ();
         int sceneId = targetPlayer.getSceneId();
 
         switch (args.size()) {
@@ -32,7 +46,9 @@ public final class TeleportCommand implements CommandHandler {
                 } // Fallthrough
             case 3:
                 try {
-                    pos = CommandHelpers.parsePosition(args.get(0), args.get(1), args.get(2), pos, rot);
+                    x = this.parseRelative(args.get(0), x);
+                    y = this.parseRelative(args.get(1), y);
+                    z = this.parseRelative(args.get(2), z);
                 } catch (NumberFormatException ignored) {
                     CommandHandler.sendMessage(
                             sender, translate(sender, "commands.teleport.invalid_position"));
@@ -43,10 +59,11 @@ public final class TeleportCommand implements CommandHandler {
                 return;
         }
 
+        Position target_pos = new Position(x, y, z);
         boolean result =
                 targetPlayer
                         .getWorld()
-                        .transferPlayerToScene(targetPlayer, sceneId, TeleportType.COMMAND, pos);
+                        .transferPlayerToScene(targetPlayer, sceneId, TeleportType.COMMAND, target_pos);
 
         if (!result) {
             CommandHandler.sendMessage(sender, translate(sender, "commands.teleport.exists_error"));
@@ -54,13 +71,7 @@ public final class TeleportCommand implements CommandHandler {
             CommandHandler.sendMessage(
                     sender,
                     translate(
-                            sender,
+                            sender, "commands.teleport.success", targetPlayer.getNickname(), x, y, z, sceneId));
-                            "commands.teleport.success",
-                            targetPlayer.getNickname(),
-                            pos.getX(),
-                            pos.getY(),
-                            pos.getZ(),
-                            sceneId));
         }
     }
 }

src/main/java/emu/grasscutter/data/DataLoader.java

@@ -1,6 +1,8 @@
 package emu.grasscutter.data;
 
 import emu.grasscutter.Grasscutter;
+import emu.grasscutter.server.http.handlers.GachaHandler;
+import emu.grasscutter.tools.Tools;
 import emu.grasscutter.utils.*;
 import java.io.*;
 import java.nio.file.*;
@@ -112,6 +114,8 @@ public class DataLoader {
         } catch (Exception e) {
             Grasscutter.getLogger().error("An error occurred while trying to check the data folder.", e);
         }
+
+        generateGachaMappings();
     }
 
     private static void checkAndCopyData(String name) {
@@ -127,4 +131,16 @@ public class DataLoader {
             FileUtils.copyResource("/defaults/data/" + name, filePath.toString());
         }
     }
+
+    private static void generateGachaMappings() {
+        var path = GachaHandler.getGachaMappingsPath();
+        if (!Files.exists(path)) {
+            try {
+                Grasscutter.getLogger().debug("Creating default '" + path + "' data");
+                Tools.createGachaMappings(path);
+            } catch (Exception exception) {
+                Grasscutter.getLogger().warn("Failed to create gacha mappings. \n" + exception);
+            }
+        }
+    }
 }

src/main/java/emu/grasscutter/data/GameData.java

@@ -214,14 +214,6 @@ public final class GameData {
     private static final Int2ObjectMap<CookRecipeData> cookRecipeDataMap =
             new Int2ObjectOpenHashMap<>();
 
-    @Getter
-    private static final Int2ObjectMap<CoopChapterData> coopChapterDataMap =
-            new Int2ObjectOpenHashMap<>();
-
-    @Getter
-    private static final Int2ObjectMap<CoopPointData> coopPointDataMap =
-            new Int2ObjectOpenHashMap<>();
-
     @Getter
     private static final Int2ObjectMap<CompoundData> compoundDataMap = new Int2ObjectOpenHashMap<>();
 

src/main/java/emu/grasscutter/data/excels/CoopChapterData.java

@@ -1,46 +0,0 @@
-package emu.grasscutter.data.excels;
-
-import com.google.gson.annotations.SerializedName;
-import emu.grasscutter.data.*;
-import java.util.List;
-import lombok.*;
-import lombok.experimental.FieldDefaults;
-
-@ResourceType(name = "CoopChapterExcelConfigData.json")
-@Getter
-@Setter // TODO: remove setters next API break
-@FieldDefaults(level = AccessLevel.PRIVATE)
-public class CoopChapterData extends GameResource {
-    @Getter(onMethod_ = @Override)
-    int id;
-
-    int avatarId;
-    //    int chapterNameTextMapHash;
-    //    int coopPageTitleTextMapHash;
-    //    int chapterSortId;
-    //    int avatarSortId;
-    //    String chapterIcon;
-    List<CoopCondition> unlockCond;
-    //    int [] unlockCondTips;
-    //    int openMaterialId;
-    //    int openMaterialNum;
-    //    String beginTimeStr;
-    //    int confidenceValue;
-    //    String pointGraphPath;
-    //    Double graphXRatio;
-    //    Double graphYRatio;
-
-    @Data
-    @FieldDefaults(level = AccessLevel.PRIVATE)
-    private static class CoopCondition {
-        @SerializedName(
-                value = "_condType",
-                alternate = {"condType"})
-        String type = "COOP_COND_NONE";
-
-        @SerializedName(
-                value = "_args",
-                alternate = {"args"})
-        int[] args;
-    }
-}

src/main/java/emu/grasscutter/data/excels/CoopPointData.java

@@ -1,24 +0,0 @@
-package emu.grasscutter.data.excels;
-
-import emu.grasscutter.data.*;
-import lombok.*;
-import lombok.experimental.FieldDefaults;
-
-@ResourceType(name = "CoopPointExcelConfigData.json")
-@Getter
-@Setter // TODO: remove setters next API break
-@FieldDefaults(level = AccessLevel.PRIVATE)
-public class CoopPointData extends GameResource {
-    @Getter(onMethod_ = @Override)
-    int id;
-
-    int chapterId;
-    String type;
-    int acceptQuest;
-    int[] postPointList;
-    //    int pointNameTextMapHash;
-    //    int pointDecTextMapHash;
-    int pointPosId;
-    //    long photoMaleHash;
-    //    long photoFemaleHash;
-}

src/main/java/emu/grasscutter/database/Database.java

@@ -0,0 +1,85 @@
+package emu.grasscutter.database;
+
+import emu.grasscutter.Grasscutter;
+import emu.grasscutter.utils.objects.DatabaseObject;
+import org.slf4j.*;
+
+import java.util.*;
+import java.util.concurrent.*;
+
+/**
+ * Complicated manager of the MongoDB database.
+ * Handles caching, data operations, and more.
+ */
+public interface Database {
+    Logger logger = LoggerFactory.getLogger("Database");
+    List<DatabaseObject<?>> objects = new CopyOnWriteArrayList<>();
+
+    /**
+     * Queues an object to be saved.
+     *
+     * @param object The object to save.
+     */
+    static void save(DatabaseObject<?> object) {
+        if (object.saveImmediately()) {
+            object.save();
+        } else {
+            objects.add(object);
+        }
+    }
+
+    /**
+     * Performs a bulk save of all deferred objects.
+     */
+    static void saveAll() {
+        var size = objects.size();
+        Database.saveAll(objects);
+
+        logger.debug("Performed auto save on {} objects.", size);
+    }
+
+    /**
+     * Performs a bulk save of all deferred objects.
+     *
+     * @param objects The objects to save.
+     */
+    static void saveAll(List<? extends DatabaseObject<?>> objects) {
+        // Sort all objects into their respective databases.
+        var gameObjects = objects.stream()
+                .filter(DatabaseObject::isGameObject)
+                .toList();
+        var accountObjects = objects.stream()
+                .filter(o -> !o.isGameObject())
+                .toList();
+
+        // Clear the collective list.
+        objects.clear();
+
+        // Save all objects.
+        var executor = DatabaseHelper.getEventExecutor();
+        if (Grasscutter.getRunMode() != Grasscutter.ServerRunMode.DISPATCH_ONLY) {
+            executor.submit(() -> {
+                DatabaseManager.getGameDatastore().save(gameObjects);
+            });
+        }
+        if (Grasscutter.getRunMode() != Grasscutter.ServerRunMode.GAME_ONLY) {
+            executor.submit(() -> {
+                DatabaseManager.getAccountDatastore().save(accountObjects);
+            });
+        }
+    }
+
+    /**
+     * Starts the auto-save thread.
+     * Runs every 5 minutes.
+     */
+    static void startSaveThread() {
+        var timer = new Timer();
+        timer.scheduleAtFixedRate(new TimerTask() {
+            @Override
+            public void run() {
+                Database.saveAll();
+            }
+        }, 0, 1000 * 60 * 5);
+    }
+}

src/main/java/emu/grasscutter/database/DatabaseHelper.java

@@ -1,7 +1,5 @@
 package emu.grasscutter.database;
 
-import static com.mongodb.client.model.Filters.eq;
-
 import dev.morphia.query.*;
 import dev.morphia.query.experimental.filters.Filters;
 import emu.grasscutter.*;
@@ -20,24 +18,19 @@ import emu.grasscutter.game.player.Player;
 import emu.grasscutter.game.quest.GameMainQuest;
 import emu.grasscutter.game.world.SceneGroupInstance;
 import emu.grasscutter.utils.objects.Returnable;
-import io.netty.util.concurrent.FastThreadLocalThread;
+import lombok.Getter;
+
+import javax.annotation.Nullable;
 import java.util.List;
 import java.util.concurrent.*;
 import java.util.stream.Stream;
-import javax.annotation.Nullable;
+
-import lombok.Getter;
+import static com.mongodb.client.model.Filters.eq;
 
 public final class DatabaseHelper {
     @Getter
     private static final ExecutorService eventExecutor =
-            new ThreadPoolExecutor(
+        Executors.newFixedThreadPool(4);
-                    6,
-                    6,
-                    60,
-                    TimeUnit.SECONDS,
-                    new LinkedBlockingDeque<>(),
-                    FastThreadLocalThread::new,
-                    new ThreadPoolExecutor.AbortPolicy());
 
     /**
      * Saves an object on the account datastore.

src/main/java/emu/grasscutter/game/HandbookActions.java

@@ -241,8 +241,7 @@ public interface HandbookActions {
 
             // Create the entity.
             for (var i = 1; i <= request.getAmount(); i++) {
-                var entity =
+                var entity = new EntityMonster(scene, entityData, player.getPosition(), level);
-                        new EntityMonster(scene, entityData, player.getPosition(), player.getRotation(), level);
                 scene.addEntity(entity);
             }
 

src/main/java/emu/grasscutter/game/achievement/Achievements.java

@@ -12,12 +12,13 @@ import emu.grasscutter.game.props.ActionReason;
 import emu.grasscutter.net.proto.AchievementOuterClass.Achievement.Status;
 import emu.grasscutter.server.event.player.PlayerCompleteAchievementEvent;
 import emu.grasscutter.server.packet.send.*;
+import lombok.*;
+import org.bson.types.ObjectId;
+
+import javax.annotation.Nullable;
 import java.util.*;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.IntSupplier;
-import javax.annotation.Nullable;
-import lombok.*;
-import org.bson.types.ObjectId;
 
 @Entity("achievements")
 @Data
@@ -44,15 +45,30 @@ public class Achievements {
         return achievements;
     }
 
+    /**
+     * Creates a blank achievements object.
+     *
+     * @return The achievements object.
+     */
+    public static Achievements blank() {
+        return Achievements.of()
+                .achievementList(init())
+                .finishedAchievementNum(0)
+                .takenGoalRewardIdList(Lists.newArrayList())
+                .build();
+    }
+
+    /**
+     * Creates and saves a blank achievements object.
+     *
+     * @param uid The UID of the player.
+     * @return The achievements object.
+     */
     public static Achievements create(int uid) {
-        var newAchievement =
+        var newAchievement = blank();
-                Achievements.of()
+        newAchievement.setUid(uid);
-                        .uid(uid)
-                        .achievementList(init())
-                        .finishedAchievementNum(0)
-                        .takenGoalRewardIdList(Lists.newArrayList())
-                        .build();
         newAchievement.save();
+
         return newAchievement;
     }
 

src/main/java/emu/grasscutter/game/activity/PlayerActivityData.java

@@ -11,15 +11,17 @@ import emu.grasscutter.game.props.ActionReason;
 import emu.grasscutter.net.proto.ActivityWatcherInfoOuterClass;
 import emu.grasscutter.server.packet.send.PacketActivityUpdateWatcherNotify;
 import emu.grasscutter.utils.JsonUtils;
-import java.util.*;
+import emu.grasscutter.utils.objects.DatabaseObject;
 import lombok.*;
 import lombok.experimental.FieldDefaults;
 
+import java.util.*;
+
 @Entity("activities")
 @Data
 @FieldDefaults(level = AccessLevel.PRIVATE)
 @Builder(builderMethodName = "of")
-public class PlayerActivityData {
+public class PlayerActivityData implements DatabaseObject<PlayerActivityData> {
     @Id String id;
     int uid;
     int activityId;
@@ -34,8 +36,25 @@ public class PlayerActivityData {
         return DatabaseHelper.getPlayerActivityData(player.getUid(), activityId);
     }
 
+    /**
+     * Saves this object to the database.
+     * As of Grasscutter 1.7.1, this is by default a {@link DatabaseObject#deferSave()} call.
+     */
     public void save() {
-        DatabaseHelper.savePlayerActivityData(this);
+        this.deferSave();
+    }
+
+    /**
+     * Saves this object to the database.
+     *
+     * @param immediate If true, this will be a {@link DatabaseObject#save()} call instead of a {@link DatabaseObject#deferSave()} call.
+     */
+    public void save(boolean immediate) {
+        if (immediate) {
+            DatabaseObject.super.save();
+        } else {
+            this.save();
+        }
     }
 
     public synchronized void addWatcherProgress(int watcherId) {

src/main/java/emu/grasscutter/game/avatar/Avatar.java

@@ -1,7 +1,5 @@
 package emu.grasscutter.game.avatar;
 
-import static emu.grasscutter.config.Configuration.GAME_OPTIONS;
-
 import dev.morphia.annotations.*;
 import emu.grasscutter.GameConstants;
 import emu.grasscutter.data.GameData;
@@ -15,7 +13,6 @@ import emu.grasscutter.data.excels.avatar.AvatarSkillDepotData.InherentProudSkil
 import emu.grasscutter.data.excels.reliquary.*;
 import emu.grasscutter.data.excels.trial.TrialAvatarTemplateData;
 import emu.grasscutter.data.excels.weapon.*;
-import emu.grasscutter.database.DatabaseHelper;
 import emu.grasscutter.game.entity.*;
 import emu.grasscutter.game.inventory.*;
 import emu.grasscutter.game.player.Player;
@@ -31,15 +28,19 @@ import emu.grasscutter.net.proto.TrialAvatarGrantRecordOuterClass.TrialAvatarGra
 import emu.grasscutter.net.proto.TrialAvatarInfoOuterClass.TrialAvatarInfo;
 import emu.grasscutter.server.packet.send.*;
 import emu.grasscutter.utils.helpers.ProtoHelper;
+import emu.grasscutter.utils.objects.DatabaseObject;
 import it.unimi.dsi.fastutil.ints.*;
-import java.util.*;
-import java.util.stream.Stream;
-import javax.annotation.*;
 import lombok.*;
 import org.bson.types.ObjectId;
 
+import javax.annotation.*;
+import java.util.*;
+import java.util.stream.Stream;
+
+import static emu.grasscutter.config.Configuration.GAME_OPTIONS;
+
 @Entity(value = "avatars", useDiscriminator = false)
-public class Avatar {
+public class Avatar implements DatabaseObject<Avatar> {
     @Transient @Getter private final Int2ObjectMap<GameItem> equips;
     @Transient @Getter private final Int2FloatOpenHashMap fightProperties;
     @Transient @Getter private final Int2FloatOpenHashMap fightPropOverrides;
@@ -989,8 +990,25 @@ public class Avatar {
         return entity != null ? entity.getId() : 0;
     }
 
+    /**
+     * Saves this object to the database.
+     * As of Grasscutter 1.7.1, this is by default a {@link DatabaseObject#deferSave()} call.
+     */
     public void save() {
-        DatabaseHelper.saveAvatar(this);
+        this.deferSave();
+    }
+
+    /**
+     * Saves this object to the database.
+     *
+     * @param immediate If true, this will be a {@link DatabaseObject#save()} call instead of a {@link DatabaseObject#deferSave()} call.
+     */
+    public void save(boolean immediate) {
+        if (immediate) {
+            DatabaseObject.super.save();
+        } else {
+            this.save();
+        }
     }
 
     public AvatarInfo toProto() {

src/main/java/emu/grasscutter/game/avatar/AvatarStorage.java

@@ -60,7 +60,7 @@ public class AvatarStorage extends BasePlayerManager implements Iterable<Avatar>
         this.avatars.put(avatar.getAvatarId(), avatar);
         this.avatarsGuid.put(avatar.getGuid(), avatar);
 
-        avatar.save();
+        avatar.save(true);
 
         return true;
     }
@@ -165,7 +165,7 @@ public class AvatarStorage extends BasePlayerManager implements Iterable<Avatar>
             if ((avatar.getAvatarId() == 10000007) || (avatar.getAvatarId() == 10000005)) {
                 avatar.setSkillDepot(skillDepot);
                 avatar.setSkillDepotData(skillDepot);
-                avatar.save();
+                avatar.save(true);
             }
         }
 

src/main/java/emu/grasscutter/game/battlepass/BattlePassManager.java

@@ -14,11 +14,12 @@ import emu.grasscutter.net.proto.BattlePassRewardTakeOptionOuterClass.BattlePass
 import emu.grasscutter.net.proto.BattlePassScheduleOuterClass.BattlePassSchedule;
 import emu.grasscutter.net.proto.BattlePassUnlockStatusOuterClass.BattlePassUnlockStatus;
 import emu.grasscutter.server.packet.send.*;
+import lombok.Getter;
+import org.bson.types.ObjectId;
+
 import java.time.*;
 import java.time.temporal.TemporalAdjusters;
 import java.util.*;
-import lombok.Getter;
-import org.bson.types.ObjectId;
 
 @Entity(value = "battlepass", useDiscriminator = false)
 public class BattlePassManager extends BasePlayerDataManager {
@@ -40,7 +41,10 @@ public class BattlePassManager extends BasePlayerDataManager {
 
     public BattlePassManager(Player player) {
         super(player);
+
         this.ownerUid = player.getUid();
+        this.missions = new HashMap<>();
+        this.takenRewards = new HashMap<>();
     }
 
     public void setPlayer(Player player) {

src/main/java/emu/grasscutter/game/entity/EntityHomeAnimal.java

@@ -18,8 +18,8 @@ public class EntityHomeAnimal extends EntityMonster implements Rebornable {
     @Getter private final int rebirthCD;
     private final AtomicBoolean disappeared = new AtomicBoolean();
 
-    public EntityHomeAnimal(Scene scene, HomeWorldAnimalData data, Position pos, Position rot) {
+    public EntityHomeAnimal(Scene scene, HomeWorldAnimalData data, Position pos) {
-        super(scene, GameData.getMonsterDataMap().get(data.getMonsterID()), pos, rot, 1);
+        super(scene, GameData.getMonsterDataMap().get(data.getMonsterID()), pos, 1);
 
         this.rebornPos = pos.clone();
         this.rebirth = data.getIsRebirth();

src/main/java/emu/grasscutter/game/entity/EntityMonster.java

@@ -54,14 +54,14 @@ public class EntityMonster extends GameEntity {
     @Getter private List<Player> playerOnBattle;
     @Nullable @Getter @Setter private SceneMonster metaMonster;
 
-    public EntityMonster(Scene scene, MonsterData monsterData, Position pos, Position rot, int level) {
+    public EntityMonster(Scene scene, MonsterData monsterData, Position pos, int level) {
         super(scene);
 
         this.id = this.getWorld().getNextEntityId(EntityIdType.MONSTER);
         this.monsterData = monsterData;
         this.fightProperties = new Int2FloatOpenHashMap();
         this.position = new Position(pos);
-        this.rotation = new Position(rot);
+        this.rotation = new Position();
         this.bornPos = this.getPosition().clone();
         this.level = level;
         this.playerOnBattle = new ArrayList<>();

src/main/java/emu/grasscutter/game/entity/GameEntity.java

@@ -15,9 +15,10 @@ import emu.grasscutter.scripts.data.controller.EntityController;
 import emu.grasscutter.server.event.entity.*;
 import emu.grasscutter.server.packet.send.PacketEntityFightPropUpdateNotify;
 import it.unimi.dsi.fastutil.ints.*;
-import java.util.*;
 import lombok.*;
 
+import java.util.*;
+
 public abstract class GameEntity {
     @Getter private final Scene scene;
     @Getter protected int id;
@@ -34,8 +35,7 @@ public abstract class GameEntity {
     @Getter @Setter private boolean lockHP;
 
     @Setter(AccessLevel.PROTECTED)
-    @Getter
+    @Getter private boolean isDead = false;
-    private boolean isDead = false;
 
     // Lua controller for specific actions
     @Getter @Setter private EntityController entityController;

src/main/java/emu/grasscutter/game/home/HomeSceneItem.java

@@ -107,8 +107,7 @@ public class HomeSceneItem {
                             return new EntityHomeAnimal(
                                     scene,
                                     GameData.getHomeWorldAnimalDataMap().get(homeAnimalItem.getFurnitureId()),
-                                    homeAnimalItem.getSpawnPos(),
+                                    homeAnimalItem.getSpawnPos());
-                                    homeAnimalItem.getSpawnRot());
                         })
                 .toList();
     }

src/main/java/emu/grasscutter/game/home/HomeWorld.java

@@ -25,6 +25,7 @@ public class HomeWorld extends World {
 
         this.home = owner.isOnline() ? owner.getHome() : GameHome.getByUid(owner.getUid());
         this.refreshModuleManager();
+        server.registerHomeWorld(this);
     }
 
     @Override

src/main/java/emu/grasscutter/game/inventory/GameItem.java

@@ -20,13 +20,14 @@ import emu.grasscutter.net.proto.ReliquaryOuterClass.Reliquary;
 import emu.grasscutter.net.proto.SceneReliquaryInfoOuterClass.SceneReliquaryInfo;
 import emu.grasscutter.net.proto.SceneWeaponInfoOuterClass.SceneWeaponInfo;
 import emu.grasscutter.net.proto.WeaponOuterClass.Weapon;
-import emu.grasscutter.utils.objects.WeightedList;
+import emu.grasscutter.utils.objects.*;
-import java.util.*;
 import lombok.*;
 import org.bson.types.ObjectId;
 
+import java.util.*;
+
 @Entity(value = "items", useDiscriminator = false)
-public class GameItem {
+public class GameItem implements DatabaseObject<GameItem> {
     @Id private ObjectId id;
     @Indexed private int ownerId;
     @Getter @Setter private int itemId;
@@ -261,14 +262,36 @@ public class GameItem {
         }
     }
 
+    /**
+     * Saves this object to the database.
+     * As of Grasscutter 1.7.1, this is by default a {@link DatabaseObject#deferSave()} call.
+     */
     public void save() {
         if (this.count > 0 && this.ownerId > 0) {
-            DatabaseHelper.saveItem(this);
+            this.deferSave();
-        } else if (this.getObjectId() != null) {
+        } else {
             DatabaseHelper.deleteItem(this);
         }
     }
 
+    /**
+     * Saves this object to the database.
+     *
+     * @param immediate If true, this will be a {@link DatabaseObject#save()} call instead of a {@link DatabaseObject#deferSave()} call.
+     */
+    public void save(boolean immediate) {
+        if (this.count < 0 || this.ownerId <= 0) {
+            DatabaseHelper.deleteItem(this);
+            return;
+        }
+
+        if (immediate) {
+            DatabaseObject.super.save();
+        } else {
+            this.save();
+        }
+    }
+
     public SceneWeaponInfo createSceneWeaponInfo() {
         var weaponInfo =
                 SceneWeaponInfo.newBuilder()

src/main/java/emu/grasscutter/game/inventory/Inventory.java

@@ -1,7 +1,5 @@
 package emu.grasscutter.game.inventory;
 
-import static emu.grasscutter.config.Configuration.INVENTORY_LIMITS;
-
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.data.GameData;
 import emu.grasscutter.data.common.ItemParamData;
@@ -18,10 +16,13 @@ import emu.grasscutter.server.packet.send.*;
 import emu.grasscutter.utils.Utils;
 import it.unimi.dsi.fastutil.ints.*;
 import it.unimi.dsi.fastutil.longs.*;
-import java.util.*;
-import javax.annotation.Nullable;
 import lombok.val;
 
+import javax.annotation.Nullable;
+import java.util.*;
+
+import static emu.grasscutter.config.Configuration.INVENTORY_LIMITS;
+
 public class Inventory extends BasePlayerManager implements Iterable<GameItem> {
     private final Long2ObjectMap<GameItem> store;
     private final Int2ObjectMap<InventoryTab> inventoryTypes;
@@ -178,7 +179,7 @@ public class Inventory extends BasePlayerManager implements Iterable<GameItem> {
                 changedItems.add(result);
             }
         }
-        if (changedItems.size() == 0) {
+        if (changedItems.isEmpty()) {
             return;
         }
         if (reason != null) {
@@ -298,8 +299,7 @@ public class Inventory extends BasePlayerManager implements Iterable<GameItem> {
 
         // Add
         switch (type) {
-            case ITEM_WEAPON:
+            case ITEM_WEAPON, ITEM_RELIQUARY -> {
-            case ITEM_RELIQUARY:
                 if (tab.getSize() >= tab.getMaxCapacity()) {
                     return null;
                 }
@@ -310,23 +310,23 @@ public class Inventory extends BasePlayerManager implements Iterable<GameItem> {
                 // Set ownership and save to db
                 item.save();
                 return item;
-            case ITEM_VIRTUAL:
+            }
+            case ITEM_VIRTUAL -> {
                 // Handle
                 this.addVirtualItem(item.getItemId(), item.getCount());
                 return item;
-            default:
+            }
+            default -> {
                 switch (item.getItemData().getMaterialType()) {
-                    case MATERIAL_AVATAR:
+                    case MATERIAL_AVATAR, MATERIAL_FLYCLOAK, MATERIAL_COSTUME, MATERIAL_NAMECARD -> {
-                    case MATERIAL_FLYCLOAK:
-                    case MATERIAL_COSTUME:
-                    case MATERIAL_NAMECARD:
                         Grasscutter.getLogger()
                                 .warn(
                                         "Attempted to add a "
                                                 + item.getItemData().getMaterialType().name()
                                                 + " to inventory, but item definition lacks isUseOnGain. This indicates a Resources error.");
                         return null;
-                    default:
+                    }
+                    default -> {
                         if (tab == null) {
                             return null;
                         }
@@ -350,7 +350,9 @@ public class Inventory extends BasePlayerManager implements Iterable<GameItem> {
                             existingItem.save();
                             return existingItem;
                         }
+                    }
                 }
+            }
         }
     }
 

src/main/java/emu/grasscutter/game/managers/blossom/BlossomActivity.java

@@ -104,8 +104,7 @@ public final class BlossomActivity {
 
                     var monsterData = GameData.getMonsterDataMap().get((int) entry);
                     var level = scene.getEntityLevel(1, worldLevelOverride);
-                    var entity =
+                    var entity = new EntityMonster(scene, monsterData, pos.nearby2d(4f), level);
-                            new EntityMonster(scene, monsterData, pos.nearby2d(4f), Position.ZERO, level);
                     scene.addEntity(entity);
                     newMonsters.add(entity);
                 }

src/main/java/emu/grasscutter/game/player/Player.java

@@ -8,7 +8,7 @@ import emu.grasscutter.data.excels.world.WeatherData;
 import emu.grasscutter.database.DatabaseHelper;
 import emu.grasscutter.game.*;
 import emu.grasscutter.game.ability.AbilityManager;
-import emu.grasscutter.game.achievement.Achievements;
+import emu.grasscutter.game.achievement.*;
 import emu.grasscutter.game.activity.ActivityManager;
 import emu.grasscutter.game.avatar.*;
 import emu.grasscutter.game.battlepass.BattlePassManager;
@@ -55,7 +55,7 @@ import emu.grasscutter.server.game.GameSession.SessionState;
 import emu.grasscutter.server.packet.send.*;
 import emu.grasscutter.utils.*;
 import emu.grasscutter.utils.helpers.DateHelper;
-import emu.grasscutter.utils.objects.FieldFetch;
+import emu.grasscutter.utils.objects.*;
 import it.unimi.dsi.fastutil.ints.*;
 import lombok.*;
 
@@ -66,7 +66,7 @@ import java.util.concurrent.*;
 import static emu.grasscutter.config.Configuration.GAME_OPTIONS;
 
 @Entity(value = "players", useDiscriminator = false)
-public class Player implements PlayerHook, FieldFetch {
+public class Player implements DatabaseObject<Player>, PlayerHook, FieldFetch {
     @Id private int id;
     @Indexed(options = @IndexOptions(unique = true))
     @Getter private String accountId;
@@ -261,6 +261,7 @@ public class Player implements PlayerHook, FieldFetch {
         this.clientAbilityInitFinishHandler = new InvokeHandler(PacketClientAbilityInitFinishNotify.class);
 
         this.birthday = new PlayerBirthday();
+        this.achievements = Achievements.blank();
         this.rewardedLevels = new HashSet<>();
         this.homeRewardedLevels = new HashSet<>();
         this.seenRealmList = new HashSet<>();
@@ -275,8 +276,10 @@ public class Player implements PlayerHook, FieldFetch {
         this.energyManager = new EnergyManager(this);
         this.resinManager = new ResinManager(this);
         this.forgingManager = new ForgingManager(this);
+        this.deforestationManager = new DeforestationManager(this);
         this.progressManager = new PlayerProgressManager(this);
         this.furnitureManager = new FurnitureManager(this);
+        this.battlePassManager = new BattlePassManager(this);
         this.cookingManager = new CookingManager(this);
         this.cookingCompoundManager = new CookingCompoundManager(this);
         this.satiationManager = new SatiationManager(this);
@@ -300,19 +303,6 @@ public class Player implements PlayerHook, FieldFetch {
         this.applyStartingSceneTags();
         this.getFlyCloakList().add(140001);
         this.getNameCardList().add(210001);
-
-        this.mapMarksManager = new MapMarksManager(this);
-        this.staminaManager = new StaminaManager(this);
-        this.sotsManager = new SotSManager(this);
-        this.energyManager = new EnergyManager(this);
-        this.resinManager = new ResinManager(this);
-        this.deforestationManager = new DeforestationManager(this);
-        this.forgingManager = new ForgingManager(this);
-        this.progressManager = new PlayerProgressManager(this);
-        this.furnitureManager = new FurnitureManager(this);
-        this.cookingManager = new CookingManager(this);
-        this.cookingCompoundManager = new CookingCompoundManager(this);
-        this.satiationManager = new SatiationManager(this);
     }
 
     @Override
@@ -1340,8 +1330,25 @@ public class Player implements PlayerHook, FieldFetch {
         this.getTeamManager().setPlayer(this);
     }
 
+    /**
+     * Saves this object to the database.
+     * As of Grasscutter 1.7.1, this is by default a {@link DatabaseObject#deferSave()} call.
+     */
     public void save() {
-        DatabaseHelper.savePlayer(this);
+        this.deferSave();
+    }
+
+    /**
+     * Saves this object to the database.
+     *
+     * @param immediate If true, this will be a {@link DatabaseObject#save()} call instead of a {@link DatabaseObject#deferSave()} call.
+     */
+    public void save(boolean immediate) {
+        if (immediate) {
+            DatabaseObject.super.save();
+        } else {
+            this.save();
+        }
     }
 
     // Called from tokenrsp
@@ -1378,6 +1385,14 @@ public class Player implements PlayerHook, FieldFetch {
         this.getPlayerProgress().setPlayer(this); // Add reference to the player.
     }
 
+    /**
+     * Invoked when the player selects their avatar.
+     */
+    public void onPlayerBorn() {
+        Grasscutter.getThreadPool().submit(
+            this.getQuestManager()::onPlayerBorn);
+    }
+
     public void onLogin() {
         // Quest - Commented out because a problem is caused if you log out while this quest is active
         /*
@@ -1504,20 +1519,19 @@ public class Player implements PlayerHook, FieldFetch {
             this.getProfile().syncWithCharacter(this);
 
             this.getCoopRequests().clear();
-            this.getEnterHomeRequests().values().forEach(req -> this.expireEnterHomeRequest(req, true));
+            this.getEnterHomeRequests().values()
+                    .forEach(req -> this.expireEnterHomeRequest(req, true));
             this.getEnterHomeRequests().clear();
 
             // Save to db
-            this.save();
+            this.save(true);
             this.getTeamManager().saveAvatars();
             this.getFriendsList().save();
 
             // Call quit event.
-            PlayerQuitEvent event = new PlayerQuitEvent(this);
+            new PlayerQuitEvent(this).call();
-            event.call();
         } catch (Throwable e) {
-            e.printStackTrace();
+            Grasscutter.getLogger().warn("Player (UID {}) failed to save.", this.getUid(), e);
-            Grasscutter.getLogger().warn("Player (UID {}) save failure", getUid());
         } finally {
             removeFromServer();
         }
@@ -1525,9 +1539,10 @@ public class Player implements PlayerHook, FieldFetch {
 
     public void removeFromServer() {
         // Remove from server.
-        //Note: DON'T DELETE BY UID,BECAUSE THERE ARE MULTIPLE SAME UID PLAYERS WHEN DUPLICATED LOGIN!
+        // Note: DON'T DELETE BY UID, BECAUSE THERE ARE MULTIPLE SAME UID PLAYERS WHEN DUPLICATED LOGIN!
-        //so I decide to delete by object rather than uid
+        //s o I decide to delete by object rather than uid
-        getServer().getPlayers().values().removeIf(player1 -> player1 == this);
+        this.getServer().getPlayers().values()
+                .removeIf(player1 -> player1 == this);
     }
 
     public int getLegendaryKey() {

src/main/java/emu/grasscutter/game/player/PlayerProgressManager.java

@@ -33,9 +33,12 @@ public final class PlayerProgressManager extends BasePlayerDataManager {
 
     public static final Set<Integer> IGNORED_OPEN_STATES =
             Set.of(
-                    1404 // OPEN_STATE_MENGDE_INFUSEDCRYSTAL, causes quest 'Mine Craft' to be given to the
+                    1404, // OPEN_STATE_MENGDE_INFUSEDCRYSTAL, causes quest 'Mine Craft' to be given to the
                     // player at the start of the game.
                     // This should be removed when city reputation is implemented.
+                    57 // OPEN_STATE_PERSONAL_LINE, causes the prompt for showing character hangout quests to
+                    // be permanently shown.
+                    // This should be removed when character story quests are implemented.
                     );
     // Set of open states that are set per default for all accounts. Can be overwritten by an entry in
     // `map`.

src/main/java/emu/grasscutter/game/player/TeamManager.java

@@ -1,11 +1,10 @@
 package emu.grasscutter.game.player;
 
-import static emu.grasscutter.config.Configuration.GAME_OPTIONS;
-
 import dev.morphia.annotations.*;
 import emu.grasscutter.*;
 import emu.grasscutter.data.GameData;
 import emu.grasscutter.data.excels.avatar.AvatarSkillDepotData;
+import emu.grasscutter.database.Database;
 import emu.grasscutter.game.avatar.Avatar;
 import emu.grasscutter.game.entity.*;
 import emu.grasscutter.game.props.*;
@@ -23,9 +22,12 @@ import emu.grasscutter.server.packet.send.*;
 import emu.grasscutter.utils.Utils;
 import it.unimi.dsi.fastutil.ints.*;
 import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
+import lombok.*;
+
 import java.util.*;
 import java.util.stream.Stream;
-import lombok.*;
+
+import static emu.grasscutter.config.Configuration.GAME_OPTIONS;
 
 @Entity
 public final class TeamManager extends BasePlayerDataManager {
@@ -404,7 +406,7 @@ public final class TeamManager extends BasePlayerDataManager {
         // Unload removed entities
         for (var entity : existingAvatars.values()) {
             this.getPlayer().getScene().removeEntity(entity);
-            entity.getAvatar().save();
+            entity.getAvatar().save(true);
         }
 
         // Set new selected character index
@@ -962,11 +964,13 @@ public final class TeamManager extends BasePlayerDataManager {
         return respawnPoint.get().getPointData().getTranPos();
     }
 
+    /**
+     * Performs a bulk save operation on all avatars.
+     */
     public void saveAvatars() {
-        // Save all avatars from active team
+        Database.saveAll(this.getActiveTeam().stream()
-        for (EntityAvatar entity : this.getActiveTeam()) {
+                .map(EntityAvatar::getAvatar)
-            entity.getAvatar().save();
+                .toList());
-        }
     }
 
     public void onPlayerLogin() { // Hack for now to fix resonances on login

src/main/java/emu/grasscutter/game/quest/QuestManager.java

@@ -1,8 +1,5 @@
 package emu.grasscutter.game.quest;
 
-import static emu.grasscutter.GameConstants.DEBUG;
-import static emu.grasscutter.config.Configuration.*;
-
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.data.GameData;
 import emu.grasscutter.data.binout.*;
@@ -15,12 +12,16 @@ import emu.grasscutter.net.proto.GivingRecordOuterClass.GivingRecord;
 import emu.grasscutter.server.packet.send.*;
 import io.netty.util.concurrent.FastThreadLocalThread;
 import it.unimi.dsi.fastutil.ints.*;
+import lombok.*;
+
+import javax.annotation.Nonnull;
 import java.util.*;
 import java.util.concurrent.*;
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
-import javax.annotation.Nonnull;
+
-import lombok.*;
+import static emu.grasscutter.GameConstants.DEBUG;
+import static emu.grasscutter.config.Configuration.*;
 
 public final class QuestManager extends BasePlayerManager {
     @Getter private final Player player;
@@ -221,11 +222,14 @@ public final class QuestManager extends BasePlayerManager {
         this.player.sendPacket(new PacketGivingRecordNotify(this.getGivingRecords()));
     }
 
-    public void onLogin() {
+    public void onPlayerBorn() {
         if (this.isQuestingEnabled()) {
             this.enableQuests();
             this.sendGivingRecords();
         }
+    }
+
+    public void onLogin() {
 
         List<GameMainQuest> activeQuests = getActiveMainQuests();
         List<GameQuest> activeSubs = new ArrayList<>(activeQuests.size());
@@ -566,7 +570,7 @@ public final class QuestManager extends BasePlayerManager {
      * @param quest The ID of the quest.
      */
     public void checkQuestAlreadyFulfilled(GameQuest quest) {
-        Grasscutter.getThreadPool()
+        eventExecutor
                 .submit(
                         () -> {
                             for (var condition : quest.getQuestData().getFinishCond()) {

src/main/java/emu/grasscutter/game/quest/conditions/ConditionMainCoopStart.java

@@ -1,21 +0,0 @@
-package emu.grasscutter.game.quest.conditions;
-
-import emu.grasscutter.data.excels.quest.QuestData;
-import emu.grasscutter.game.player.Player;
-import emu.grasscutter.game.quest.QuestValueCond;
-import emu.grasscutter.game.quest.enums.QuestCond;
-
-@QuestValueCond(QuestCond.QUEST_COND_MAIN_COOP_START)
-public class ConditionMainCoopStart extends BaseCondition {
-
-    @Override
-    public boolean execute(
-            Player owner,
-            QuestData questData,
-            QuestData.QuestAcceptCondition condition,
-            String paramStr,
-            int... params) {
-        return condition.getParam()[0] == params[0]
-                && (condition.getParam()[1] == 0 || condition.getParam()[1] == params[1]);
-    }
-}

src/main/java/emu/grasscutter/game/quest/enums/QuestCond.java

@@ -54,7 +54,7 @@ public enum QuestCond implements QuestTrigger {
     QUEST_COND_QUEST_GLOBAL_VAR_LESS(46),
     QUEST_COND_PERSONAL_LINE_UNLOCK(47),
     QUEST_COND_CITY_REPUTATION_REQUEST(48), // missing
-    QUEST_COND_MAIN_COOP_START(49),
+    QUEST_COND_MAIN_COOP_START(49), // missing
     QUEST_COND_MAIN_COOP_ENTER_SAVE_POINT(50), // missing
     QUEST_COND_CITY_REPUTATION_LEVEL(51), // missing, only NPC groups
     QUEST_COND_CITY_REPUTATION_UNLOCK(52), // missing, currently unused

src/main/java/emu/grasscutter/game/world/Scene.java

@@ -816,8 +816,8 @@ public class Scene {
 
                     int level = this.getEntityLevel(entry.getLevel(), worldLevelOverride);
 
-                    EntityMonster monster =
+                    EntityMonster monster = new EntityMonster(this, data, entry.getPos(), level);
-                            new EntityMonster(this, data, entry.getPos(), entry.getRot(), level);
+                    monster.getRotation().set(entry.getRot());
                     monster.setGroupId(entry.getGroup().getGroupId());
                     monster.setPoseId(entry.getPoseId());
                     monster.setConfigId(entry.getConfigId());

src/main/java/emu/grasscutter/game/world/World.java

@@ -1,7 +1,5 @@
 package emu.grasscutter.game.world;
 
-import static emu.grasscutter.server.event.player.PlayerTeleportEvent.TeleportType.SCRIPT;
-
 import emu.grasscutter.data.GameData;
 import emu.grasscutter.data.excels.dungeon.DungeonData;
 import emu.grasscutter.game.entity.*;
@@ -20,10 +18,13 @@ import emu.grasscutter.server.game.GameServer;
 import emu.grasscutter.server.packet.send.*;
 import emu.grasscutter.utils.ConversionUtils;
 import it.unimi.dsi.fastutil.ints.*;
-import java.util.*;
 import lombok.*;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.*;
+
+import static emu.grasscutter.server.event.player.PlayerTeleportEvent.TeleportType.SCRIPT;
+
 public class World implements Iterable<Player> {
     @Getter private final GameServer server;
     @Getter private Player host;
@@ -72,8 +73,6 @@ public class World implements Iterable<Player> {
         this.scenes = Int2ObjectMaps.synchronize(new Int2ObjectOpenHashMap<>());
         this.entity = new EntityWorld(this);
         this.lastUpdateTime = System.currentTimeMillis();
-
-        server.registerWorld(this);
     }
 
     public int getLevelEntityId() {
@@ -268,7 +267,7 @@ public class World implements Iterable<Player> {
         scene.removePlayer(player);
 
         // Info packet for other players
-        if (this.getPlayers().size() > 0) {
+        if (!this.getPlayers().isEmpty()) {
             this.updatePlayerInfos(player);
         }
 
@@ -398,50 +397,37 @@ public class World implements Iterable<Player> {
             return false;
         }
 
-        Scene oldScene = player.getScene();
+        Scene oldScene = null;
-        var newScene = this.getSceneById(teleportProperties.getSceneId());
+        if (player.getScene() != null) {
+            oldScene = player.getScene();
 
-        // Move directly in the same scene.
-        if (newScene == oldScene && teleportProperties.getTeleportType() == TeleportType.COMMAND) {
-            // Set player position and rotation
-            if (teleportProperties.getTeleportTo() != null) {
-                player.getPosition().set(teleportProperties.getTeleportTo());
-            }
-            if (teleportProperties.getTeleportRot() != null) {
-                player.getRotation().set(teleportProperties.getTeleportRot());
-            }
-            player.sendPacket(new PacketSceneEntityAppearNotify(player));
-            return true;
-        }
-
-        if (oldScene != null) {
             // Don't deregister scenes if the player is going to tp back into them
-            if (oldScene == newScene) {
+            if (oldScene.getId() == teleportProperties.getSceneId()) {
                 oldScene.setDontDestroyWhenEmpty(true);
             }
+
             oldScene.removePlayer(player);
         }
 
-        if (newScene != null) {
+        var newScene = this.getSceneById(teleportProperties.getSceneId());
-            newScene.addPlayer(player);
+        newScene.addPlayer(player);
 
-            player.getTeamManager().applyAbilities(newScene);
+        player.getTeamManager().applyAbilities(newScene);
 
-            // Dungeon
+        // Dungeon
-            // Dungeon system is handling this already
+        // Dungeon system is handling this already
-            // if(dungeonData!=null){
+        // if(dungeonData!=null){
-            //     var dungeonManager = new DungeonManager(newScene, dungeonData);
+        //     var dungeonManager = new DungeonManager(newScene, dungeonData);
-            //     dungeonManager.startDungeon();
+        //     dungeonManager.startDungeon();
-            // }
+        // }
 
-            SceneConfig config = newScene.getScriptManager().getConfig();
+        SceneConfig config = newScene.getScriptManager().getConfig();
-            if (teleportProperties.getTeleportTo() == null && config != null) {
+        if (teleportProperties.getTeleportTo() == null && config != null) {
-                if (config.born_pos != null) {
+            if (config.born_pos != null) {
-                    teleportProperties.setTeleportTo(config.born_pos);
+                teleportProperties.setTeleportTo(config.born_pos);
-                }
+            }
-                if (config.born_rot != null) {
+            if (config.born_rot != null) {
-                    teleportProperties.setTeleportRot(config.born_rot);
+                teleportProperties.setTeleportRot(config.born_rot);
-                }
             }
         }
 
@@ -453,7 +439,7 @@ public class World implements Iterable<Player> {
             player.getRotation().set(teleportProperties.getTeleportRot());
         }
 
-        if (oldScene != null && newScene != null && newScene != oldScene) {
+        if (oldScene != null && newScene != oldScene) {
             newScene.setPrevScenePoint(oldScene.getPrevScenePoint());
             oldScene.setDontDestroyWhenEmpty(false);
         }

src/main/java/emu/grasscutter/net/KcpChannel.java

@@ -0,0 +1,22 @@
+package emu.grasscutter.net;
+
+public interface KcpChannel {
+    /**
+     * Event fired when the client connects.
+     *
+     * @param tunnel The tunnel.
+     */
+    void onConnected(KcpTunnel tunnel);
+
+    /**
+     * Event fired when the client disconnects.
+     */
+    void onDisconnected();
+
+    /**
+     * Event fired when data is received from the client.
+     *
+     * @param bytes The data received.
+     */
+    void onMessage(byte[] bytes);
+}

src/main/java/emu/grasscutter/net/KcpTunnel.java

@@ -0,0 +1,22 @@
+package emu.grasscutter.net;
+
+import java.net.InetSocketAddress;
+
+public interface KcpTunnel {
+    /**
+     * @return The address of the client.
+     */
+    InetSocketAddress getAddress();
+
+    /**
+     * Sends bytes to the client.
+     *
+     * @param bytes The bytes to send.
+     */
+    void writeData(byte[] bytes);
+
+    /**
+     * Closes the connection.
+     */
+    void close();
+}

src/main/java/emu/grasscutter/scripts/SceneScriptManager.java

@@ -1037,7 +1037,8 @@ public class SceneScriptManager {
         }
 
         // Spawn mob
-        EntityMonster entity = new EntityMonster(getScene(), data, monster.pos, monster.rot, level);
+        EntityMonster entity = new EntityMonster(getScene(), data, monster.pos, level);
+        entity.getRotation().set(monster.rot);
         entity.setGroupId(groupId);
         entity.setBlockId(blockId);
         entity.setConfigId(monster.config_id);

src/main/java/emu/grasscutter/server/game/GameServer.java

@@ -1,55 +1,49 @@
 package emu.grasscutter.server.game;
 
-import static emu.grasscutter.config.Configuration.*;
-import static emu.grasscutter.utils.lang.Language.translate;
-
 import emu.grasscutter.*;
 import emu.grasscutter.Grasscutter.ServerRunMode;
 import emu.grasscutter.database.DatabaseHelper;
 import emu.grasscutter.game.Account;
 import emu.grasscutter.game.battlepass.BattlePassSystem;
-import emu.grasscutter.game.chat.ChatSystem;
+import emu.grasscutter.game.chat.*;
-import emu.grasscutter.game.chat.ChatSystemHandler;
 import emu.grasscutter.game.combine.CombineManger;
-import emu.grasscutter.game.drop.DropSystem;
+import emu.grasscutter.game.drop.*;
-import emu.grasscutter.game.drop.DropSystemLegacy;
 import emu.grasscutter.game.dungeons.DungeonSystem;
 import emu.grasscutter.game.expedition.ExpeditionSystem;
 import emu.grasscutter.game.gacha.GachaSystem;
-import emu.grasscutter.game.home.HomeWorld;
+import emu.grasscutter.game.home.*;
-import emu.grasscutter.game.home.HomeWorldMPSystem;
+import emu.grasscutter.game.managers.cooking.*;
-import emu.grasscutter.game.managers.cooking.CookingCompoundManager;
-import emu.grasscutter.game.managers.cooking.CookingManager;
 import emu.grasscutter.game.managers.energy.EnergyManager;
 import emu.grasscutter.game.managers.stamina.StaminaManager;
 import emu.grasscutter.game.player.Player;
 import emu.grasscutter.game.quest.QuestSystem;
 import emu.grasscutter.game.shop.ShopSystem;
-import emu.grasscutter.game.systems.AnnouncementSystem;
+import emu.grasscutter.game.systems.*;
-import emu.grasscutter.game.systems.InventorySystem;
-import emu.grasscutter.game.systems.MultiplayerSystem;
 import emu.grasscutter.game.talk.TalkSystem;
 import emu.grasscutter.game.tower.TowerSystem;
-import emu.grasscutter.game.world.World;
+import emu.grasscutter.game.world.*;
-import emu.grasscutter.game.world.WorldDataSystem;
 import emu.grasscutter.net.packet.PacketHandler;
 import emu.grasscutter.net.proto.SocialDetailOuterClass.SocialDetail;
 import emu.grasscutter.server.dispatch.DispatchClient;
 import emu.grasscutter.server.event.game.ServerTickEvent;
-import emu.grasscutter.server.event.internal.ServerStartEvent;
+import emu.grasscutter.server.event.internal.*;
-import emu.grasscutter.server.event.internal.ServerStopEvent;
 import emu.grasscutter.server.event.types.ServerEvent;
 import emu.grasscutter.server.scheduler.ServerTaskScheduler;
 import emu.grasscutter.task.TaskMap;
 import emu.grasscutter.utils.Utils;
 import it.unimi.dsi.fastutil.ints.*;
+import kcp.highway.*;
+import lombok.*;
+import org.jetbrains.annotations.*;
+import emu.grasscutter.server.game.session.GameSessionManager;
+
 import java.net.*;
 import java.time.*;
 import java.util.*;
 import java.util.concurrent.*;
-import kcp.highway.*;
+
-import lombok.*;
+import static emu.grasscutter.config.Configuration.*;
-import org.jetbrains.annotations.*;
+import static emu.grasscutter.utils.lang.Language.translate;
 
 @Getter
 public final class GameServer extends KcpServer implements Iterable<Player> {
@@ -60,6 +54,7 @@ public final class GameServer extends KcpServer implements Iterable<Player> {
     private final Set<World> worlds;
     private final Int2ObjectMap<HomeWorld> homeWorlds;
 
+    @Getter private boolean started = false;
     @Setter private DispatchClient dispatchClient;
 
     // Server systems
@@ -140,7 +135,7 @@ public final class GameServer extends KcpServer implements Iterable<Player> {
         channelConfig.setUseConvChannel(true);
         channelConfig.setAckNoDelay(false);
 
-        this.init(GameSessionManager.getListener(), channelConfig, address);
+        this.init(GameSessionManager.getInstance(), channelConfig, address);
 
         EnergyManager.initialize();
         StaminaManager.initialize();
@@ -311,6 +306,11 @@ public final class GameServer extends KcpServer implements Iterable<Player> {
         world.save(); // Save the player's world
     }
 
+    public void registerHomeWorld(HomeWorld homeWorld) {
+        this.getHomeWorlds().put(homeWorld.getOwnerUid(), homeWorld);
+        this.registerWorld(homeWorld);
+    }
+
     public HomeWorld getHomeWorldOrCreate(Player owner) {
         return this.getHomeWorlds()
                 .computeIfAbsent(owner.getUid(), (uid) -> new HomeWorld(this, owner));
@@ -342,6 +342,8 @@ public final class GameServer extends KcpServer implements Iterable<Player> {
                 .info(translate("messages.game.address_bind", GAME_INFO.accessAddress, address.getPort()));
         ServerStartEvent event = new ServerStartEvent(ServerEvent.Type.GAME, OffsetDateTime.now());
         event.call();
+
+        this.started = true;
     }
 
     public void onServerShutdown() {
@@ -356,10 +358,10 @@ public final class GameServer extends KcpServer implements Iterable<Player> {
         this.stop(); // Stop the server.
 
         try {
-            var threadPool = GameSessionManager.getLogicThread();
+            var threadPool = GameSessionManager.getExecutor();
 
             // Shutdown network thread.
-            threadPool.shutdownGracefully();
+            threadPool.shutdown();
             // Wait for the network thread to finish.
             if (!threadPool.awaitTermination(5, TimeUnit.SECONDS)) {
                 Grasscutter.getLogger().error("Logic thread did not terminate!");

src/main/java/emu/grasscutter/server/game/GameServerPacketHandler.java

@@ -1,7 +1,5 @@
 package emu.grasscutter.server.game;
 
-import static emu.grasscutter.config.Configuration.GAME_INFO;
-
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.Grasscutter.ServerDebugMode;
 import emu.grasscutter.net.packet.*;
@@ -9,6 +7,8 @@ import emu.grasscutter.server.event.game.ReceivePacketEvent;
 import emu.grasscutter.server.game.GameSession.SessionState;
 import it.unimi.dsi.fastutil.ints.*;
 
+import static emu.grasscutter.config.Configuration.GAME_INFO;
+
 public final class GameServerPacketHandler {
     private final Int2ObjectMap<PacketHandler> handlers;
 
@@ -76,13 +76,11 @@ public final class GameServerPacketHandler {
                 }
 
                 // Invoke event.
-                ReceivePacketEvent event = new ReceivePacketEvent(session, opcode, payload);
+                var event = new ReceivePacketEvent(session, opcode, payload);
-                event.call();
+                if (event.call()) // If event is not canceled, continue.
-                if (!event.isCanceled()) // If event is not canceled, continue.
+                    handler.handle(session, header, event.getPacketData());
-                handler.handle(session, header, event.getPacketData());
             } catch (Exception ex) {
-                // TODO Remove this when no more needed
+                Grasscutter.getLogger().warn("Unable to handle packet.", ex);
-                ex.printStackTrace();
             }
             return; // Packet successfully handled
         }

src/main/java/emu/grasscutter/server/game/GameSession.java

@@ -1,24 +1,26 @@
 package emu.grasscutter.server.game;
 
-import static emu.grasscutter.config.Configuration.*;
-import static emu.grasscutter.utils.lang.Language.translate;
-
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.Grasscutter.ServerDebugMode;
 import emu.grasscutter.game.Account;
 import emu.grasscutter.game.player.Player;
+import emu.grasscutter.net.*;
 import emu.grasscutter.net.packet.*;
 import emu.grasscutter.server.event.game.SendPacketEvent;
 import emu.grasscutter.utils.*;
 import io.netty.buffer.*;
+import lombok.*;
+
 import java.io.File;
 import java.net.InetSocketAddress;
 import java.nio.file.Path;
-import lombok.*;
 
-public class GameSession implements GameSessionManager.KcpChannel {
+import static emu.grasscutter.config.Configuration.*;
+import static emu.grasscutter.utils.lang.Language.translate;
+
+public class GameSession implements KcpChannel {
     private final GameServer server;
-    private GameSessionManager.KcpTunnel tunnel;
+    private KcpTunnel tunnel;
 
     @Getter @Setter private Account account;
     @Getter private Player player;
@@ -146,7 +148,7 @@ public class GameSession implements GameSessionManager.KcpChannel {
                 if (packet.shouldEncrypt) {
                     Crypto.xor(bytes, packet.useDispatchKey() ? Crypto.DISPATCH_KEY : this.encryptKey);
                 }
-                tunnel.writeData(bytes);
+                this.tunnel.writeData(bytes);
             } catch (Exception ignored) {
                 Grasscutter.getLogger().debug("Unable to send packet to client.");
             }
@@ -154,13 +156,13 @@ public class GameSession implements GameSessionManager.KcpChannel {
     }
 
     @Override
-    public void onConnected(GameSessionManager.KcpTunnel tunnel) {
+    public void onConnected(KcpTunnel tunnel) {
         this.tunnel = tunnel;
         Grasscutter.getLogger().info(translate("messages.game.connect", this.getAddress().toString()));
     }
 
     @Override
-    public void handleReceive(byte[] bytes) {
+    public void onMessage(byte[] bytes) {
         // Decrypt and turn back into a packet
         Crypto.xor(bytes, useSecretKey() ? this.encryptKey : Crypto.DISPATCH_KEY);
         ByteBuf packet = Unpooled.wrappedBuffer(bytes);
@@ -226,8 +228,8 @@ public class GameSession implements GameSessionManager.KcpChannel {
                 // Handle
                 getServer().getPacketHandler().handle(this, opcode, header, payload);
             }
-        } catch (Exception e) {
+        } catch (Exception exception) {
-            e.printStackTrace();
+            Grasscutter.getLogger().warn("Unable to handle packet.", exception);
         } finally {
             // byteBuf.release(); //Needn't
             packet.release();
@@ -235,8 +237,9 @@ public class GameSession implements GameSessionManager.KcpChannel {
     }
 
     @Override
-    public void handleClose() {
+    public void onDisconnected() {
         setState(SessionState.INACTIVE);
+
         // send disconnection pack in case of reconnection
         Grasscutter.getLogger()
                 .info(translate("messages.game.disconnect", this.getAddress().toString()));

src/main/java/emu/grasscutter/server/game/GameSessionManager.java

@@ -1,114 +0,0 @@
-package emu.grasscutter.server.game;
-
-import emu.grasscutter.Grasscutter;
-import emu.grasscutter.utils.Utils;
-import io.netty.buffer.*;
-import io.netty.channel.DefaultEventLoop;
-import java.net.InetSocketAddress;
-import java.util.concurrent.ConcurrentHashMap;
-import kcp.highway.*;
-import lombok.Getter;
-
-public class GameSessionManager {
-    @Getter private static final DefaultEventLoop logicThread = new DefaultEventLoop();
-    private static final ConcurrentHashMap<Ukcp, GameSession> sessions = new ConcurrentHashMap<>();
-    private static final KcpListener listener =
-            new KcpListener() {
-                @Override
-                public void onConnected(Ukcp ukcp) {
-                    int times = 0;
-                    GameServer server = Grasscutter.getGameServer();
-                    while (server == null) { // Waiting server to establish
-                        try {
-                            Thread.sleep(1000);
-                        } catch (InterruptedException e) {
-                            e.printStackTrace();
-                            ukcp.close();
-                            return;
-                        }
-                        if (times++ > 5) {
-                            Grasscutter.getLogger().error("Service is not available!");
-                            ukcp.close();
-                            return;
-                        }
-                        server = Grasscutter.getGameServer();
-                    }
-                    GameSession conversation = new GameSession(server);
-                    conversation.onConnected(
-                            new KcpTunnel() {
-                                @Override
-                                public InetSocketAddress getAddress() {
-                                    return ukcp.user().getRemoteAddress();
-                                }
-
-                                @Override
-                                public void writeData(byte[] bytes) {
-                                    ByteBuf buf = Unpooled.wrappedBuffer(bytes);
-                                    ukcp.write(buf);
-                                    buf.release();
-                                }
-
-                                @Override
-                                public void close() {
-                                    ukcp.close();
-                                }
-
-                                @Override
-                                public int getSrtt() {
-                                    return ukcp.srtt();
-                                }
-                            });
-                    sessions.put(ukcp, conversation);
-                }
-
-                @Override
-                public void handleReceive(ByteBuf buf, Ukcp kcp) {
-                    var byteData = Utils.byteBufToArray(buf);
-                    logicThread.execute(
-                            () -> {
-                                try {
-                                    var conversation = sessions.get(kcp);
-                                    if (conversation != null) {
-                                        conversation.handleReceive(byteData);
-                                    }
-                                } catch (Exception e) {
-                                    e.printStackTrace();
-                                }
-                            });
-                }
-
-                @Override
-                public void handleException(Throwable ex, Ukcp ukcp) {}
-
-                @Override
-                public void handleClose(Ukcp ukcp) {
-                    GameSession conversation = sessions.get(ukcp);
-                    if (conversation != null) {
-                        conversation.handleClose();
-                        sessions.remove(ukcp);
-                    }
-                }
-            };
-
-    public static KcpListener getListener() {
-        return listener;
-    }
-
-    public interface KcpTunnel {
-        InetSocketAddress getAddress();
-
-        void writeData(byte[] bytes);
-
-        void close();
-
-        int getSrtt();
-    }
-
-    interface KcpChannel {
-        void onConnected(KcpTunnel tunnel);
-
-        void handleClose();
-
-        void handleReceive(byte[] bytes);
-    }
-}

src/main/java/emu/grasscutter/server/game/session/GameSessionHandler.java

@@ -0,0 +1,31 @@
+package emu.grasscutter.server.game.session;
+
+import emu.grasscutter.net.KcpTunnel;
+import io.netty.buffer.Unpooled;
+import kcp.highway.Ukcp;
+import lombok.*;
+
+import java.net.InetSocketAddress;
+
+@RequiredArgsConstructor
+public final class GameSessionHandler implements KcpTunnel {
+    @Getter private final Ukcp handle;
+
+    @Override
+    public InetSocketAddress getAddress() {
+        return this.getHandle().user().getRemoteAddress();
+    }
+
+    @Override
+    public void writeData(byte[] bytes) {
+        var buffer = Unpooled.wrappedBuffer(bytes);
+        this.getHandle().write(buffer);
+
+        buffer.release();
+    }
+
+    @Override
+    public void close() {
+        this.getHandle().close();
+    }
+}

src/main/java/emu/grasscutter/server/game/session/GameSessionManager.java

@@ -0,0 +1,89 @@
+package emu.grasscutter.server.game.session;
+
+import emu.grasscutter.Grasscutter;
+import emu.grasscutter.server.game.*;
+import emu.grasscutter.utils.Utils;
+import io.netty.buffer.ByteBuf;
+import kcp.highway.*;
+import lombok.Getter;
+
+import java.util.Map;
+import java.util.concurrent.*;
+
+public final class GameSessionManager implements KcpListener {
+    @Getter private static final GameSessionManager instance
+        = new GameSessionManager();
+    @Getter private static final ExecutorService executor
+        = Executors.newWorkStealingPool();
+    @Getter private static final Map<Ukcp, GameSession> sessions
+        = new ConcurrentHashMap<>();
+
+    /**
+     * Waits for the game server to be ready.
+     *
+     * @return The game server.
+     */
+    private GameServer waitForServer() {
+        var server = Grasscutter.getGameServer();
+        var times = 0; while (server == null || !server.isStarted()) {
+            Utils.sleep(1000); // Wait 1s for the server to start.
+            if (times++ > 5) {
+                Grasscutter.getLogger().error("Game server has not started in a reasonable time.");
+                return null;
+            }
+
+            server = Grasscutter.getGameServer();
+        }
+
+        return server;
+    }
+
+    @Override
+    public void onConnected(Ukcp ukcp) {
+        // Fetch the game server.
+        var server = this.waitForServer();
+        if (server == null) {
+            ukcp.close();
+            return;
+        }
+
+        // Create a new session.
+        var session = sessions.compute(ukcp, (k, existing) -> {
+            // Close an existing session.
+            if (existing != null) {
+                existing.close();
+            }
+
+            return new GameSession(server);
+        });
+
+        // Connect the session.
+        session.onConnected(new GameSessionHandler(ukcp));
+    }
+
+    @Override
+    public void handleReceive(ByteBuf byteBuf, Ukcp ukcp) {
+        // Get the session.
+        var session = sessions.get(ukcp);
+        if (session == null) {
+            ukcp.close(); return;
+        }
+
+        // Handle the message in a separate thread.
+        var bytes = Utils.byteBufToArray(byteBuf);
+        executor.submit(() -> session.onMessage(bytes));
+    }
+
+    @Override
+    public void handleException(Throwable throwable, Ukcp ukcp) {
+        Grasscutter.getLogger().error("Exception in game session.", throwable);
+    }
+
+    @Override
+    public void handleClose(Ukcp ukcp) {
+        var session = sessions.remove(ukcp);
+        if (session != null) {
+            session.close();
+        }
+    }
+}

src/main/java/emu/grasscutter/server/packet/recv/HandlerCancelCoopTaskReq.java

@@ -1,21 +0,0 @@
-package emu.grasscutter.server.packet.recv;
-
-import emu.grasscutter.Grasscutter;
-import emu.grasscutter.net.packet.*;
-import emu.grasscutter.net.proto.CancelCoopTaskReqOuterClass;
-import emu.grasscutter.server.game.GameSession;
-import emu.grasscutter.server.packet.send.PacketCancelCoopTaskRsp;
-
-@Opcodes(PacketOpcodes.CancelCoopTaskReq)
-public class HandlerCancelCoopTaskReq extends PacketHandler {
-
-    @Override
-    public void handle(GameSession session, byte[] header, byte[] payload) throws Exception {
-        CancelCoopTaskReqOuterClass.CancelCoopTaskReq req =
-                CancelCoopTaskReqOuterClass.CancelCoopTaskReq.parseFrom(payload);
-        var chapterId = req.getChapterId();
-        Grasscutter.getLogger().warn("Call to unimplemented packet CancelCoopTaskReq");
-        // TODO: Actually cancel the quests.
-        session.send(new PacketCancelCoopTaskRsp(chapterId));
-    }
-}

src/main/java/emu/grasscutter/server/packet/recv/HandlerPersonalLineAllDataReq.java

@@ -2,7 +2,6 @@ package emu.grasscutter.server.packet.recv;
 
 import emu.grasscutter.net.packet.*;
 import emu.grasscutter.server.game.GameSession;
-import emu.grasscutter.server.packet.send.PacketCoopDataNotify;
 import emu.grasscutter.server.packet.send.PacketPersonalLineAllDataRsp;
 
 @Opcodes(PacketOpcodes.PersonalLineAllDataReq)
@@ -13,7 +12,5 @@ public class HandlerPersonalLineAllDataReq extends PacketHandler {
         session.send(
                 new PacketPersonalLineAllDataRsp(
                         session.getPlayer().getQuestManager().getMainQuests().values()));
-        // TODO: this should maybe be at player login?
-        session.send(new PacketCoopDataNotify());
     }
 }

src/main/java/emu/grasscutter/server/packet/recv/HandlerQuestCreateEntityReq.java

@@ -61,7 +61,7 @@ public class HandlerQuestCreateEntityReq extends PacketHandler {
                 val monsterId = entity.getMonsterId();
                 val level = entity.getLevel();
                 MonsterData monsterData = GameData.getMonsterDataMap().get(monsterId);
-                gameEntity = new EntityMonster(scene, monsterData, pos, rot, level);
+                gameEntity = new EntityMonster(scene, monsterData, pos, level);
             }
             case NPC_ID -> {}
         }

src/main/java/emu/grasscutter/server/packet/recv/HandlerSetPlayerBornDataReq.java

@@ -69,6 +69,7 @@ public class HandlerSetPlayerBornDataReq extends PacketHandler {
 
         // Login done
         session.getPlayer().onLogin();
+        session.getPlayer().onPlayerBorn();
 
         // Born resp packet
         session.send(new BasePacket(PacketOpcodes.SetPlayerBornDataRsp));

src/main/java/emu/grasscutter/server/packet/recv/HandlerStartCoopPointReq.java

@@ -1,31 +0,0 @@
-package emu.grasscutter.server.packet.recv;
-
-import emu.grasscutter.data.GameData;
-import emu.grasscutter.game.quest.enums.QuestCond;
-import emu.grasscutter.net.packet.*;
-import emu.grasscutter.net.proto.StartCoopPointReqOuterClass;
-import emu.grasscutter.server.game.GameSession;
-import emu.grasscutter.server.packet.send.PacketStartCoopPointRsp;
-
-@Opcodes(PacketOpcodes.StartCoopPointReq)
-public class HandlerStartCoopPointReq extends PacketHandler {
-
-    @Override
-    public void handle(GameSession session, byte[] header, byte[] payload) throws Exception {
-        StartCoopPointReqOuterClass.StartCoopPointReq req =
-                StartCoopPointReqOuterClass.StartCoopPointReq.parseFrom(payload);
-        var coopPoint = req.getCoopPoint();
-
-        var coopPointData =
-                GameData.getCoopPointDataMap().values().stream()
-                        .filter(i -> i.getId() == coopPoint)
-                        .toList();
-        if (!coopPointData.isEmpty()) {
-            var player = session.getPlayer();
-            var questManager = player.getQuestManager();
-            questManager.queueEvent(
-                    QuestCond.QUEST_COND_MAIN_COOP_START, coopPointData.get(0).getChapterId(), 0);
-        }
-        session.send(new PacketStartCoopPointRsp(coopPoint));
-    }
-}

src/main/java/emu/grasscutter/server/packet/send/PacketCancelCoopTaskRsp.java

@@ -1,16 +0,0 @@
-package emu.grasscutter.server.packet.send;
-
-import emu.grasscutter.net.packet.*;
-import emu.grasscutter.net.proto.CancelCoopTaskRspOuterClass;
-
-public class PacketCancelCoopTaskRsp extends BasePacket {
-
-    public PacketCancelCoopTaskRsp(int chapterId) {
-        super(PacketOpcodes.SetCoopChapterViewedRsp);
-
-        CancelCoopTaskRspOuterClass.CancelCoopTaskRsp proto =
-                CancelCoopTaskRspOuterClass.CancelCoopTaskRsp.newBuilder().setChapterId(chapterId).build();
-
-        this.setData(proto);
-    }
-}

src/main/java/emu/grasscutter/server/packet/send/PacketCoopDataNotify.java

@@ -1,49 +0,0 @@
-package emu.grasscutter.server.packet.send;
-
-import emu.grasscutter.data.GameData;
-import emu.grasscutter.net.packet.*;
-import emu.grasscutter.net.proto.CoopChapterOuterClass;
-import emu.grasscutter.net.proto.CoopDataNotifyOuterClass;
-import emu.grasscutter.net.proto.CoopPointOuterClass;
-
-public class PacketCoopDataNotify extends BasePacket {
-
-    public PacketCoopDataNotify() {
-        super(PacketOpcodes.CoopDataNotify);
-
-        var proto = CoopDataNotifyOuterClass.CoopDataNotify.newBuilder();
-        proto.setIsHaveProgress(false);
-
-        // TODO: implement: determine the actual current progress point.
-        // Add every chapter and add the start point to each chapter regardless of actual progress.
-        GameData.getCoopChapterDataMap()
-                .values()
-                .forEach(
-                        i -> {
-                            var chapter = CoopChapterOuterClass.CoopChapter.newBuilder();
-                            chapter.setId(i.getId());
-
-                            // TODO: implement: look at unlockCond to determine what state each chapter should be
-                            // in.
-                            // Set every chapter to "Accept" regardless of accept conditions.
-                            chapter.setStateValue(3); // 3 == STATE_ACCEPT
-
-                            var point = CoopPointOuterClass.CoopPoint.newBuilder();
-                            var pointList =
-                                    GameData.getCoopPointDataMap().values().stream()
-                                            .filter(
-                                                    j -> j.getChapterId() == i.getId() && j.getType().equals("POINT_START"))
-                                            .toList();
-
-                            if (!pointList.isEmpty()) {
-                                int pointId = pointList.get(0).getId();
-                                point.setId(pointId);
-                                chapter.addCoopPointList(point);
-                            }
-
-                            proto.addChapterList(chapter);
-                        });
-
-        this.setData(proto);
-    }
-}

src/main/java/emu/grasscutter/server/packet/send/PacketStartCoopPointRsp.java

@@ -1,16 +0,0 @@
-package emu.grasscutter.server.packet.send;
-
-import emu.grasscutter.net.packet.*;
-import emu.grasscutter.net.proto.StartCoopPointRspOuterClass;
-
-public class PacketStartCoopPointRsp extends BasePacket {
-
-    public PacketStartCoopPointRsp(int coopPoint) {
-        super(PacketOpcodes.StartCoopPointRsp);
-
-        StartCoopPointRspOuterClass.StartCoopPointRsp proto =
-                StartCoopPointRspOuterClass.StartCoopPointRsp.newBuilder().setCoopPoint(coopPoint).build();
-
-        this.setData(proto);
-    }
-}

src/main/java/emu/grasscutter/tools/Tools.java

@@ -10,7 +10,6 @@ import emu.grasscutter.data.common.ItemUseData;
 import emu.grasscutter.data.excels.*;
 import emu.grasscutter.data.excels.achievement.AchievementData;
 import emu.grasscutter.data.excels.avatar.AvatarData;
-import emu.grasscutter.server.http.handlers.GachaHandler;
 import emu.grasscutter.utils.*;
 import emu.grasscutter.utils.lang.Language;
 import emu.grasscutter.utils.lang.Language.TextStrings;
@@ -312,19 +311,8 @@ public final class Tools {
         return sbs.stream().map(StringBuilder::toString).toList();
     }
 
-    public static void generateGachaMappings() {
-        var path = GachaHandler.getGachaMappingsPath();
-        if (!Files.exists(path)) {
-            try {
-                Grasscutter.getLogger().debug("Creating default '" + path + "' data");
-                Tools.createGachaMappings(path);
-            } catch (Exception exception) {
-                Grasscutter.getLogger().warn("Failed to create gacha mappings. \n" + exception);
-            }
-        }
-    }
-
     public static void createGachaMappings(Path location) throws IOException {
+        ResourceLoader.loadResources();
         List<String> jsons = createGachaMappingJsons();
         var usedLocales = new HashSet<String>();
         StringBuilder sb = new StringBuilder("mappings = {\n");

src/main/java/emu/grasscutter/utils/objects/DatabaseObject.java

@@ -0,0 +1,42 @@
+package emu.grasscutter.utils.objects;
+
+import emu.grasscutter.Grasscutter;
+import emu.grasscutter.Grasscutter.ServerRunMode;
+import emu.grasscutter.database.*;
+
+public interface DatabaseObject<T> {
+    /**
+     * @return Does this object belong in the game database?
+     */
+    default boolean isGameObject() {
+        return true;
+    }
+
+    /**
+     * @return Should this object be saved immediately?
+     */
+    default boolean saveImmediately() {
+        return false;
+    }
+
+    /**
+     * Performs a deferred save.
+     * This object will save as a group with other objects.
+     */
+    default void deferSave() {
+        Database.save(this);
+    }
+
+    /**
+     * Attempts to save this object to the database.
+     */
+    default void save() {
+        if (this.isGameObject()) {
+            DatabaseManager.getGameDatastore().save(this);
+        } else if (Grasscutter.getRunMode() != ServerRunMode.GAME_ONLY) {
+            DatabaseManager.getAccountDatastore().save(this);
+        } else {
+            throw new UnsupportedOperationException("Unable to store an account object while in game-only mode.");
+        }
+    }
+}

src/test/java/io/grasscutter/GrasscutterTest.java

@@ -1,60 +1,18 @@
 package io.grasscutter;
 
-import com.mchange.util.AssertException;
+import io.grasscutter.virtual.*;
-import emu.grasscutter.Grasscutter;
+import lombok.*;
-import emu.grasscutter.config.Configuration;
-import java.io.IOException;
-import lombok.Getter;
 import okhttp3.OkHttpClient;
-import okhttp3.Request;
-import org.junit.jupiter.api.Assertions;
-import org.junit.jupiter.api.BeforeAll;
-import org.junit.jupiter.api.DisplayName;
-import org.junit.jupiter.api.Test;
 
-/** Testing entrypoint for {@link Grasscutter}. */
+import java.util.concurrent.*;
+
 public final class GrasscutterTest {
-    @Getter private static final OkHttpClient httpClient = new OkHttpClient();
+    @Getter
+    public static final OkHttpClient httpClient = new OkHttpClient();
+    @Getter public static final ExecutorService executor = Executors.newSingleThreadExecutor();
 
-    @Getter private static int httpPort = -1;
+    @Getter public static VirtualAccount account;
-    @Getter private static int gamePort = -1;
+    @Setter
-
+    @Getter public static VirtualPlayer player;
-    /**
+    @Getter public static VirtualGameSession gameSession;
-     * Creates an HTTP URL.
-     *
-     * @param route The route to use.
-     * @return The URL.
-     */
-    public static String http(String route) {
-        return "http://127.0.0.1:" + GrasscutterTest.httpPort + "/" + route;
-    }
-
-    @BeforeAll
-    public static void entry() {
-        try {
-            // Start Grasscutter.
-            Grasscutter.main(new String[] {"-test"});
-        } catch (Exception ignored) {
-            throw new AssertException("Grasscutter failed to start.");
-        }
-
-        // Set the ports.
-        GrasscutterTest.httpPort = Configuration.SERVER.http.bindPort;
-        GrasscutterTest.gamePort = Configuration.SERVER.game.bindPort;
-    }
-
-    @Test
-    @DisplayName("HTTP server check")
-    public void checkHttpServer() {
-        // Create a request.
-        var request = new Request.Builder().url(GrasscutterTest.http("")).build();
-
-        // Perform the request.
-        try (var response = GrasscutterTest.httpClient.newCall(request).execute()) {
-            // Check the response.
-            Assertions.assertTrue(response.isSuccessful());
-        } catch (IOException exception) {
-            throw new AssertionError(exception);
-        }
-    }
 }

src/test/java/io/grasscutter/TestUtils.java

@@ -0,0 +1,17 @@
+package io.grasscutter;
+
+import emu.grasscutter.utils.Utils;
+import emu.grasscutter.utils.objects.Returnable;
+
+public interface TestUtils {
+    /**
+     * Waits for a condition to be met.
+     *
+     * @param condition The condition.
+     */
+    static void waitFor(Returnable<Boolean> condition) {
+        while (!condition.invoke()) {
+            Utils.sleep(100);
+        }
+    }
+}

src/test/java/io/grasscutter/tests/BaseServerTest.java

@@ -0,0 +1,61 @@
+package io.grasscutter.tests;
+
+import com.mchange.util.AssertException;
+import emu.grasscutter.Grasscutter;
+import emu.grasscutter.config.Configuration;
+import io.grasscutter.GrasscutterTest;
+import io.grasscutter.virtual.*;
+import lombok.*;
+import okhttp3.*;
+import org.junit.jupiter.api.*;
+
+import java.io.IOException;
+
+/** Testing entrypoint for {@link Grasscutter}. */
+public final class BaseServerTest {
+    @Getter private static int httpPort = -1;
+    @Getter private static int gamePort = -1;
+
+    /**
+     * Creates an HTTP URL.
+     *
+     * @param route The route to use.
+     * @return The URL.
+     */
+    public static String http(String route) {
+        return "http://127.0.0.1:" + BaseServerTest.httpPort + "/" + route;
+    }
+
+    @BeforeAll
+    public static void entry() {
+        try {
+            // Start Grasscutter.
+            Grasscutter.main(new String[] {"-test"});
+        } catch (Exception ignored) {
+            throw new AssertException("Grasscutter failed to start.");
+        }
+
+        // Set the ports.
+        BaseServerTest.httpPort = Configuration.SERVER.http.bindPort;
+        BaseServerTest.gamePort = Configuration.SERVER.game.bindPort;
+
+        // Create virtual instances.
+        GrasscutterTest.account = new VirtualAccount();
+        GrasscutterTest.gameSession = new VirtualGameSession();
+    }
+
+    @Test
+    @DisplayName("HTTP server check")
+    public void checkHttpServer() {
+        // Create a request.
+        var request = new Request.Builder().url(BaseServerTest.http("")).build();
+
+        // Perform the request.
+        try (var response = GrasscutterTest.httpClient.newCall(request).execute()) {
+            // Check the response.
+            Assertions.assertTrue(response.isSuccessful());
+        } catch (IOException exception) {
+            throw new AssertionError(exception);
+        }
+    }
+}

src/test/java/io/grasscutter/tests/LoginTest.java

@@ -0,0 +1,67 @@
+package io.grasscutter.tests;
+
+import emu.grasscutter.GameConstants;
+import emu.grasscutter.net.packet.PacketOpcodes;
+import emu.grasscutter.net.proto.*;
+import emu.grasscutter.server.game.session.GameSessionManager;
+import io.grasscutter.*;
+import kcp.highway.*;
+import lombok.Getter;
+import org.junit.jupiter.api.*;
+import org.junit.jupiter.api.MethodOrderer.OrderAnnotation;
+
+@TestMethodOrder(OrderAnnotation.class)
+public final class LoginTest {
+    @Getter private static final Ukcp KCP = new Ukcp(
+        null, null, null,
+        new ChannelConfig(), null);
+
+    @Test
+    @Order(1)
+    @DisplayName("Connect to server")
+    public void connectToServer() {
+        var session = GrasscutterTest.getGameSession();
+
+        // Register the session.
+        GameSessionManager.getSessions().put(KCP, session);
+
+        // Try connecting to the server.
+        session.exchangeToken();
+        Assertions.assertTrue(session.waitForPacket(
+                PacketOpcodes.GetPlayerTokenRsp, 5));
+    }
+
+    @Test
+    @Order(2)
+    @DisplayName("Login to server")
+    public void loginToServer() {
+        var account = GrasscutterTest.getAccount();
+        var session = GrasscutterTest.getGameSession();
+
+        // Wait for the login response.
+        TestUtils.waitFor(session::useSecretKey);
+
+        // Send the login packet.
+        session.receive(
+                PacketOpcodes.PlayerLoginReq,
+                PlayerLoginReqOuterClass.PlayerLoginReq.newBuilder()
+                        .setToken(account.getToken())
+                        .build()
+        );
+        // Wait for the login response.
+        Assertions.assertTrue(session.waitForPacket(
+                PacketOpcodes.PlayerLoginRsp, 5));
+
+        // Send the born data request.
+        session.receive(
+                PacketOpcodes.SetPlayerBornDataReq,
+                SetPlayerBornDataReqOuterClass.SetPlayerBornDataReq.newBuilder()
+                        .setAvatarId(GameConstants.MAIN_CHARACTER_FEMALE)
+                        .setNickName("Virtual Player")
+                        .build()
+        );
+        // Wait for the born data response.
+        Assertions.assertTrue(session.waitForPacket(
+                PacketOpcodes.SetPlayerBornDataRsp, 5));
+    }
+}

src/test/java/io/grasscutter/virtual/VirtualAccount.java

@@ -0,0 +1,23 @@
+package io.grasscutter.virtual;
+
+import emu.grasscutter.game.Account;
+
+import java.util.Locale;
+
+@SuppressWarnings("deprecation")
+public final class VirtualAccount extends Account {
+    public VirtualAccount() {
+        super();
+
+        this.setId("virtual_account");
+        this.setUsername("virtual_account");
+        this.setPassword("virtual_account");
+
+        this.setReservedPlayerUid(10001);
+        this.setEmail("virtual_account@grasscutter.io");
+        this.setLocale(Locale.US);
+
+        this.generateSessionKey();
+        this.generateLoginToken();
+    }
+}

src/test/java/io/grasscutter/virtual/VirtualGameSession.java

@@ -0,0 +1,142 @@
+package io.grasscutter.virtual;
+
+import com.google.protobuf.GeneratedMessageV3;
+import emu.grasscutter.Grasscutter;
+import emu.grasscutter.game.player.Player;
+import emu.grasscutter.net.packet.*;
+import emu.grasscutter.net.proto.GetPlayerTokenReqOuterClass.GetPlayerTokenReq;
+import emu.grasscutter.net.proto.PacketHeadOuterClass.PacketHead;
+import emu.grasscutter.server.game.GameSession;
+import emu.grasscutter.utils.Crypto;
+import io.grasscutter.GrasscutterTest;
+import io.netty.buffer.Unpooled;
+import org.slf4j.*;
+
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.function.Function;
+
+public final class VirtualGameSession extends GameSession {
+    private static final Logger logger = LoggerFactory.getLogger("Game Session");
+
+    private final Map<Integer, Set<Function<byte[], Boolean>>> listeners = new HashMap<>();
+
+    public VirtualGameSession() {
+        super(Grasscutter.getGameServer());
+
+        this.setAccount(GrasscutterTest.getAccount());
+        this.onConnected(new VirtualKcpTunnel());
+    }
+
+    /**
+     * Performs an exchange with the server for the player's token.
+     */
+    public void exchangeToken() {
+        var account = GrasscutterTest.getAccount();
+
+        this.receive(
+                PacketOpcodes.GetPlayerTokenReq,
+                GetPlayerTokenReq.newBuilder()
+                        .setAccountUid(account.getId())
+                        .setAccountToken(account.getToken())
+                        .build()
+        );
+    }
+
+    /**
+     * Registers a listener for a packet.
+     *
+     * @param packetId The packet's ID.
+     * @param listener The listener to register.
+     */
+    public void addPacketListener(int packetId, Function<byte[], Boolean> listener) {
+        var listeners = this.listeners.computeIfAbsent(
+                packetId, k -> new HashSet<>());
+        listeners.add(listener);
+    }
+
+    /**
+     * Waits for a packet to be received.
+     *
+     * @param packetId The packet's ID.
+     * @param timeout The timeout in milliseconds.
+     */
+    public boolean waitForPacket(int packetId, int timeout) {
+        var promise = new CompletableFuture<byte[]>();
+        this.addPacketListener(packetId, data -> {
+            promise.complete(data);
+            return false;
+        });
+
+        try {
+            promise.get(timeout, TimeUnit.SECONDS);
+            return true;
+        } catch (Exception e) {
+            return false;
+        }
+    }
+
+    @Override
+    public synchronized void setPlayer(Player player) {
+        var newPlayer = new VirtualPlayer();
+
+        GrasscutterTest.setPlayer(newPlayer);
+        super.setPlayer(newPlayer);
+    }
+
+    /**
+     * Receives a packet from the client.
+     *
+     * @param packetId The packet's ID.
+     * @param message The packet to receive.
+     */
+    public void receive(int packetId, GeneratedMessageV3 message) {
+        // Craft a packet header.
+        var header = PacketHead.newBuilder()
+                .setSentMs(System.currentTimeMillis())
+                .build();
+        // Serialize the message.
+        var headerBytes = header.toByteArray();
+        var messageBytes = message.toByteArray();
+
+        // Wrap the message into a packet.
+        var packet = Unpooled.buffer(12);
+        packet.writeShort(17767); // Packet header.
+        packet.writeShort(packetId); // Packet "opcode" or ID.
+        packet.writeShort(headerBytes.length); // Packet head length.
+        packet.writeInt(messageBytes.length); // Packet body length.
+        packet.writeBytes(headerBytes); // Packet head.
+        packet.writeBytes(messageBytes); // Packet body.
+        packet.writeShort(-30293); // Packet footer.
+
+        // Serialize the packet.
+        var data = packet.array();
+        // Encrypt the packet if specified.
+        Crypto.xor(data, this.useSecretKey() ?
+                Crypto.ENCRYPT_KEY : Crypto.DISPATCH_KEY);
+
+        // Dispatch the message to the server.
+        GrasscutterTest.getExecutor()
+                .submit(() -> this.onMessage(data));
+    }
+
+    @Override
+    public void send(BasePacket packet) {
+        // Invoke packet handlers.
+        var listeners = this.listeners.get(packet.getOpcode());
+        if (listeners != null) {
+            var copy = new HashSet<>(listeners);
+            for (var listener : copy) {
+                if (listener.apply(packet.getData())) {
+                    listeners.remove(listener);
+                }
+            }
+        }
+
+        // Log the received packet.
+        logger.info("Received packet {} ({}) of length {} (header is {}).",
+            PacketOpcodesUtils.getOpcodeName(packet.getOpcode()), packet.getOpcode(),
+            packet.getData() == null ? "null" : packet.getData().length,
+            packet.getHeader() == null ? "null" : packet.getHeader().length);
+    }
+}

src/test/java/io/grasscutter/virtual/VirtualKcpTunnel.java

@@ -0,0 +1,21 @@
+package io.grasscutter.virtual;
+
+import emu.grasscutter.net.KcpTunnel;
+import java.net.InetSocketAddress;
+
+public final class VirtualKcpTunnel implements KcpTunnel {
+    @Override
+    public InetSocketAddress getAddress() {
+        return new InetSocketAddress(1000);
+    }
+
+    @Override
+    public void writeData(byte[] bytes) {
+        throw new UnsupportedOperationException("Cannot write to a virtual KCP tunnel");
+    }
+
+    @Override
+    public void close() {
+        System.exit(0);
+    }
+}

src/test/java/io/grasscutter/virtual/VirtualPlayer.java

@@ -0,0 +1,13 @@
+package io.grasscutter.virtual;
+
+import emu.grasscutter.game.player.Player;
+import io.grasscutter.GrasscutterTest;
+import io.grasscutter.tests.BaseServerTest;
+
+public final class VirtualPlayer extends Player {
+    public VirtualPlayer() {
+        super(GrasscutterTest.getGameSession());
+
+        this.setAccount(GrasscutterTest.getAccount());
+    }
+}