Merge branch 'development' into api

# Conflicts:
#	src/main/java/emu/grasscutter/plugin/api/ServerHook.java

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

@@ -3,10 +3,10 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.data.GenshinData;
+import emu.grasscutter.data.GameData;
 import emu.grasscutter.data.def.ItemData;
-import emu.grasscutter.game.GenshinPlayer;
-import emu.grasscutter.game.inventory.GenshinItem;
+import emu.grasscutter.game.inventory.GameItem;
+import emu.grasscutter.game.player.Player;
 import emu.grasscutter.game.props.ActionReason;
 import emu.grasscutter.server.packet.send.PacketItemAddHintNotify;
 
@@ -18,7 +18,7 @@ import java.util.List;
 public final class GiveCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         int target, item, lvl, amount = 1;
         if (sender == null && args.size() < 2) {
             CommandHandler.sendMessage(null, "Usage: give <player> <itemId|itemName> [amount] [level]");
@@ -99,14 +99,14 @@ public final class GiveCommand implements CommandHandler {
                 break;
         }
 
-        GenshinPlayer targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
+        Player targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
 
         if (targetPlayer == null) {
             CommandHandler.sendMessage(sender, "Player not found.");
             return;
         }
 
-        ItemData itemData = GenshinData.getItemDataMap().get(item);
+        ItemData itemData = GameData.getItemDataMap().get(item);
         if (itemData == null) {
             CommandHandler.sendMessage(sender, "Invalid item id.");
             return;
@@ -121,11 +121,11 @@ public final class GiveCommand implements CommandHandler {
                     String.format("Given %s with level %s %s times to %s", item, lvl, amount, target));
     }
 
-    private void item(GenshinPlayer player, ItemData itemData, int amount, int lvl) {
+    private void item(Player player, ItemData itemData, int amount, int lvl) {
         if (itemData.isEquip()) {
-            List<GenshinItem> items = new LinkedList<>();
+            List<GameItem> items = new LinkedList<>();
             for (int i = 0; i < amount; i++) {
-                GenshinItem item = new GenshinItem(itemData);
+                GameItem item = new GameItem(itemData);
                 item.setCount(amount);
                 item.setLevel(lvl);
                 item.setPromoteLevel(0);
@@ -144,13 +144,11 @@ public final class GiveCommand implements CommandHandler {
                 }
                 items.add(item);
             }
-            player.getInventory().addItems(items);
-            player.sendPacket(new PacketItemAddHintNotify(items, ActionReason.SubfieldDrop));
+            player.getInventory().addItems(items, ActionReason.SubfieldDrop);
         } else {
-            GenshinItem genshinItem = new GenshinItem(itemData);
-            genshinItem.setCount(amount);
-            player.getInventory().addItem(genshinItem);
-            player.sendPacket(new PacketItemAddHintNotify(genshinItem, ActionReason.SubfieldDrop));
+            GameItem item = new GameItem(itemData);
+            item.setCount(amount);
+            player.getInventory().addItem(item, ActionReason.SubfieldDrop);
         }
     }
 }

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

@@ -3,7 +3,7 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -12,7 +12,7 @@ import java.util.List;
 public final class GodModeCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (sender == null) {
             CommandHandler.sendMessage(null, "Run this command in-game.");
             return; // TODO: toggle player's godmode statue from console or other players
@@ -32,7 +32,7 @@ public final class GodModeCommand implements CommandHandler {
         } else {
             target = sender.getUid();
         }
-        GenshinPlayer targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
+        Player targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
         if (targetPlayer == null) {
             CommandHandler.sendMessage(sender, "Player not found.");
             return;

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

@@ -2,7 +2,7 @@ package emu.grasscutter.command.commands;
 
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 import emu.grasscutter.game.props.FightProperty;
 import emu.grasscutter.server.packet.send.PacketAvatarFightPropUpdateNotify;
 import emu.grasscutter.server.packet.send.PacketAvatarLifeStateChangeNotify;
@@ -13,7 +13,7 @@ import java.util.List;
         description = "Heal all characters in your current team.", permission = "player.heal")
 public final class HealCommand implements CommandHandler {
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (sender == null) {
             CommandHandler.sendMessage(null, "Run this command in-game.");
             return;

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

@@ -3,7 +3,7 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
 import emu.grasscutter.command.CommandMap;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.*;
 
@@ -12,7 +12,7 @@ import java.util.*;
 public final class HelpCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer player, List<String> args) {
+    public void execute(Player player, List<String> args) {
         if (args.size() < 1) {
             HashMap<String, CommandHandler> handlers = CommandMap.getInstance().getHandlers();
             List<Command> annotations = new ArrayList<>();
@@ -53,7 +53,7 @@ public final class HelpCommand implements CommandHandler {
         }
     }
 
-    void SendAllHelpMessage(GenshinPlayer player, List<Command> annotations) {
+    void SendAllHelpMessage(Player player, List<Command> annotations) {
         if (player == null) {
             StringBuilder builder = new StringBuilder("\nAvailable commands:\n");
             annotations.forEach(annotation -> {

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

@@ -3,7 +3,7 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -12,10 +12,10 @@ import java.util.List;
 public final class KickCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         int target = Integer.parseInt(args.get(0));
 
-        GenshinPlayer targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
+        Player targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
         if (targetPlayer == null) {
             CommandHandler.sendMessage(sender, "Player not found.");
             return;

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

@@ -3,9 +3,9 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
-import emu.grasscutter.game.GenshinScene;
 import emu.grasscutter.game.entity.EntityMonster;
+import emu.grasscutter.game.player.Player;
+import emu.grasscutter.game.world.Scene;
 
 import java.util.List;
 
@@ -14,9 +14,9 @@ import java.util.List;
 public final class KillAllCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
-        GenshinScene scene;
-        GenshinPlayer genshinPlayer;
+    public void execute(Player sender, List<String> args) {
+        Scene mainScene;
+        Player targetPlayer;
 
         try {
             switch (args.size()) {
@@ -25,38 +25,38 @@ public final class KillAllCommand implements CommandHandler {
                         CommandHandler.sendMessage(null, "Usage: killall [playerUid] [sceneId]");
                         return;
                     }
-                    scene = sender.getScene();
+                    mainScene = sender.getScene();
                     break;
                 case 1: // [playerUid]
-                    genshinPlayer = Grasscutter.getGameServer().getPlayerByUid(Integer.parseInt(args.get(0)));
-                    if (genshinPlayer == null) {
+                    targetPlayer = Grasscutter.getGameServer().getPlayerByUid(Integer.parseInt(args.get(0)));
+                    if (targetPlayer == null) {
                         CommandHandler.sendMessage(sender, "Player not found or offline.");
                         return;
                     }
-                    scene = genshinPlayer.getScene();
+                    mainScene = targetPlayer.getScene();
                     break;
                 case 2: // [playerUid] [sceneId]
-                    genshinPlayer = Grasscutter.getGameServer().getPlayerByUid(Integer.parseInt(args.get(0)));
-                    if (genshinPlayer == null) {
+                    targetPlayer = Grasscutter.getGameServer().getPlayerByUid(Integer.parseInt(args.get(0)));
+                    if (targetPlayer == null) {
                         CommandHandler.sendMessage(sender, "Player not found or offline.");
                         return;
                     }
-                    GenshinScene genshinScene = sender.getWorld().getSceneById(Integer.parseInt(args.get(1)));
-                    if (genshinScene == null) {
+                    Scene scene = sender.getWorld().getSceneById(Integer.parseInt(args.get(1)));
+                    if (scene == null) {
                         CommandHandler.sendMessage(sender, "Scene not found in player world");
                         return;
                     }
-                    scene = genshinScene;
+                    mainScene = scene;
                     break;
                 default:
                     CommandHandler.sendMessage(sender, "Usage: killall [playerUid] [sceneId]");
                     return;
             }
 
-            scene.getEntities().values().stream()
+            mainScene.getEntities().values().stream()
                     .filter(entity -> entity instanceof EntityMonster)
-                    .forEach(entity -> scene.killEntity(entity, 0));
-            CommandHandler.sendMessage(sender, "Killing all monsters in scene " + scene.getId());
+                    .forEach(entity -> mainScene.killEntity(entity, 0));
+            CommandHandler.sendMessage(sender, "Killing all monsters in scene " + mainScene.getId());
         } catch (NumberFormatException ignored) {
             CommandHandler.sendMessage(sender, "Invalid arguments.");
         }

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

@@ -3,8 +3,8 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
 import emu.grasscutter.game.entity.EntityAvatar;
+import emu.grasscutter.game.player.Player;
 import emu.grasscutter.game.props.FightProperty;
 import emu.grasscutter.game.props.LifeState;
 import emu.grasscutter.server.packet.send.PacketEntityFightPropUpdateNotify;
@@ -17,7 +17,7 @@ import java.util.List;
 public final class KillCharacterCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         int target;
         if (sender == null) {
             // from console
@@ -48,7 +48,7 @@ public final class KillCharacterCommand implements CommandHandler {
             }
         }
 
-        GenshinPlayer targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
+        Player targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
         if (targetPlayer == null) {
             CommandHandler.sendMessage(sender, "Player not found or offline.");
             return;

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

@@ -3,7 +3,7 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 import java.util.Map;
@@ -12,8 +12,8 @@ import java.util.Map;
 public final class ListCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
-        Map<Integer, GenshinPlayer> playersMap = Grasscutter.getGameServer().getPlayers();
+    public void execute(Player sender, List<String> args) {
+        Map<Integer, Player> playersMap = Grasscutter.getGameServer().getPlayers();
 
         CommandHandler.sendMessage(sender, String.format("There are %s player(s) online:", playersMap.size()));
 

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

@@ -4,7 +4,7 @@ import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
 import emu.grasscutter.game.Account;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -13,7 +13,7 @@ import java.util.List;
 public final class PermissionCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (args.size() < 3) {
             CommandHandler.sendMessage(sender, "Usage: permission <add|remove> <username> <permission>");
             return;

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

@@ -2,7 +2,7 @@ package emu.grasscutter.command.commands;
 
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -11,7 +11,7 @@ import java.util.List;
 public final class PositionCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (sender == null) {
             CommandHandler.sendMessage(null, "Run this command in-game.");
             return;

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

@@ -3,7 +3,7 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -12,10 +12,12 @@ import java.util.List;
 public final class ReloadCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         CommandHandler.sendMessage(sender, "Reloading config.");
         Grasscutter.loadConfig();
         Grasscutter.getGameServer().getGachaManager().load();
+        Grasscutter.getGameServer().getDropManager().load();
+        Grasscutter.getGameServer().getShopManager().load();
         Grasscutter.getDispatchServer().loadQueries();
         CommandHandler.sendMessage(sender, "Reload complete.");
     }

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

@@ -2,9 +2,9 @@ package emu.grasscutter.command.commands;
 
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
-import emu.grasscutter.game.avatar.GenshinAvatar;
+import emu.grasscutter.game.avatar.Avatar;
 import emu.grasscutter.game.entity.EntityAvatar;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -14,7 +14,7 @@ import java.util.List;
 public final class ResetConstCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (sender == null) {
             CommandHandler.sendMessage(null, "Run this command in-game.");
             return;
@@ -29,14 +29,14 @@ public final class ResetConstCommand implements CommandHandler {
                 return;
             }
 
-            GenshinAvatar avatar = entity.getAvatar();
+            Avatar avatar = entity.getAvatar();
             this.resetConstellation(avatar);
 
             sender.dropMessage("Constellations for " + avatar.getAvatarData().getName() + " have been reset. Please relog to see changes.");
         }
     }
 
-    private void resetConstellation(GenshinAvatar avatar) {
+    private void resetConstellation(Avatar avatar) {
         avatar.getTalentIdList().clear();
         avatar.setCoreProudSkillLevel(0);
         avatar.recalcStats();

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

@@ -2,7 +2,7 @@ package emu.grasscutter.command.commands;
 
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -10,7 +10,7 @@ import java.util.List;
 public final class RestartCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         sender.getSession().close();
     }
 }

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

+package emu.grasscutter.command.commands;
+
+import emu.grasscutter.Grasscutter;
+import emu.grasscutter.command.Command;
+import emu.grasscutter.command.CommandHandler;
+import emu.grasscutter.database.DatabaseHelper;
+import emu.grasscutter.game.mail.Mail;
+import emu.grasscutter.game.player.Player;
+import emu.grasscutter.server.packet.send.PacketMailChangeNotify;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+
+@Command(label = "sendmail", usage = "sendmail <userId|all|help> [templateId]",
+        description = "Sends mail to the specified user. The usage of this command changes based on it's composition state.", permission = "server.sendmail")
+public class SendMailCommand implements CommandHandler {
+
+    // TODO: You should be able to do /sendmail and then just send subsequent messages until you finish
+    //  However, due to the current nature of the command system, I don't think this is possible without rewriting
+    //  the command system (again). For now this will do
+
+    // Key = User that is constructing the mail.
+    private static HashMap<Integer, MailBuilder> mailBeingConstructed = new HashMap<Integer, MailBuilder>();
+
+    // Yes this is awful and I hate it.
+    @Override
+    public void execute(Player sender, List<String> args) {
+        int senderId;
+        if(sender != null) {
+            senderId = sender.getUid();
+        } else {
+            senderId = -1;
+        }
+
+        if (!mailBeingConstructed.containsKey(senderId)) {
+            switch (args.size()) {
+                case 1 -> {
+                    MailBuilder mailBuilder;
+                    switch (args.get(0).toLowerCase()) {
+                        case "help" -> {
+                            CommandHandler.sendMessage(sender, this.getClass().getAnnotation(Command.class).description() + "\nUsage: " + this.getClass().getAnnotation(Command.class).usage());
+                            return;
+                        }
+                        case "all" -> mailBuilder = new MailBuilder(true, new Mail());
+                        default -> {
+                            if (DatabaseHelper.getPlayerById(Integer.parseInt(args.get(0))) != null) {
+                                mailBuilder = new MailBuilder(Integer.parseInt(args.get(0)), new Mail());
+                                break;
+                            } else {
+                                CommandHandler.sendMessage(sender, "The user with an id of '" + args.get(0) + "' does not exist");
+                                return;
+                            }
+                        }
+                    }
+                    mailBeingConstructed.put(senderId, mailBuilder);
+                    CommandHandler.sendMessage(sender, "Starting composition of message.\nPlease use `/sendmail <title>` to continue.\nYou can use `/sendmail stop` at any time");
+                }
+                case 2 -> CommandHandler.sendMessage(sender, "Mail templates coming soon implemented...");
+                default -> CommandHandler.sendMessage(sender, "Invalid arguments.\nUsage `/sendmail <userId|all|help> [templateId]`");
+            }
+        } else {
+            MailBuilder mailBuilder = mailBeingConstructed.get(senderId);
+
+            if (args.size() >= 1) {
+                switch (args.get(0).toLowerCase()) {
+                    case "stop" -> {
+                        mailBeingConstructed.remove(senderId);
+                        CommandHandler.sendMessage(sender, "Message sending cancelled");
+                        return;
+                    }
+                    case "finish" -> {
+                        if (mailBuilder.constructionStage == 3) {
+                            if (mailBuilder.sendToAll == false) {
+                                Grasscutter.getGameServer().getPlayerByUid(mailBuilder.recipient, true).sendMail(mailBuilder.mail);
+                                CommandHandler.sendMessage(sender, "Message sent to user " + mailBuilder.recipient + "!");
+                            } else {
+                                for (Player player : DatabaseHelper.getAllPlayers()) {
+                                    Grasscutter.getGameServer().getPlayerByUid(player.getUid(), true).sendMail(mailBuilder.mail);
+                                }
+                                CommandHandler.sendMessage(sender, "Message sent to all users!");
+                            }
+                            mailBeingConstructed.remove(senderId);
+                        } else {
+                            CommandHandler.sendMessage(sender, "Message composition not at final stage.\nPlease use `/sendmail " + getConstructionArgs(mailBuilder.constructionStage) + "` or `/sendmail stop` to cancel");
+                        }
+                        return;
+                    }
+                    case "help" -> {
+                        CommandHandler.sendMessage(sender, "Please use `/sendmail " + getConstructionArgs(mailBuilder.constructionStage) + "`");
+                        return;
+                    }
+                    default -> {
+                        switch (mailBuilder.constructionStage) {
+                            case 0 -> {
+                                String title = String.join(" ", args.subList(0, args.size()));
+                                mailBuilder.mail.mailContent.title = title;
+                                CommandHandler.sendMessage(sender, "Message title set as '" + title + "'.\nUse '/sendmail <content>' to continue.");
+                                mailBuilder.constructionStage++;
+                            }
+                            case 1 -> {
+                                String contents = String.join(" ", args.subList(0, args.size()));
+                                mailBuilder.mail.mailContent.content = contents;
+                                CommandHandler.sendMessage(sender, "Message contents set as '" + contents + "'.\nUse '/sendmail <sender>' to continue.");
+                                mailBuilder.constructionStage++;
+                            }
+                            case 2 -> {
+                                String msgSender = String.join(" ", args.subList(0, args.size()));
+                                mailBuilder.mail.mailContent.sender = msgSender;
+                                CommandHandler.sendMessage(sender, "Message sender set as '" + msgSender + "'.\nUse '/sendmail <itemId|itemName|finish> [amount] [level]' to continue.");
+                                mailBuilder.constructionStage++;
+                            }
+                            case 3 -> {
+                                // Literally just copy-pasted from the give command lol.
+                                int item, lvl, amount = 1;
+                                switch (args.size()) {
+                                    default -> { // *No args*
+                                        CommandHandler.sendMessage(sender, "Usage: give [player] <itemId|itemName> [amount]");
+                                        return;
+                                    }
+                                    case 1 -> { // <itemId|itemName>
+                                        try {
+                                            item = Integer.parseInt(args.get(0));
+                                            lvl = 1;
+                                        } catch (NumberFormatException ignored) {
+                                            // TODO: Parse from item name using GM Handbook.
+                                            CommandHandler.sendMessage(sender, "Invalid item id.");
+                                            return;
+                                        }
+                                    }
+                                    case 2 -> { // <itemId|itemName> [amount]
+                                        lvl = 1;
+                                        item = Integer.parseInt(args.get(0));
+                                        amount = Integer.parseInt(args.get(1));
+                                    }
+                                    case 3 -> { // <itemId|itemName> [amount] [level]
+                                        try {
+                                            item = Integer.parseInt(args.get(0));
+                                            amount = Integer.parseInt(args.get(1));
+                                            lvl = Integer.parseInt(args.get(2));
+
+                                        } catch (NumberFormatException ignored) {
+                                            // TODO: Parse from item name using GM Handbook.
+                                            CommandHandler.sendMessage(sender, "Invalid item or player ID.");
+                                            return;
+                                        }
+                                    }
+                                }
+                                mailBuilder.mail.itemList.add(new Mail.MailItem(item, amount, lvl));
+                                CommandHandler.sendMessage(sender, String.format("Attached %s of %s (level %s) to the message.\nContinue adding more items or use `/sendmail finish` to send the message.", amount, item, lvl));
+                            }
+                        }
+                    }
+                }
+            } else {
+                CommandHandler.sendMessage(sender, "Invalid arguments \n Please use `/sendmail " + getConstructionArgs(mailBuilder.constructionStage));
+            }
+        }
+    }
+
+    private String getConstructionArgs(int stage) {
+        switch (stage) {
+            case 0 -> {
+                return "<title>";
+            }
+            case 1 -> {
+                return "<message>";
+            }
+            case 2 -> {
+                return "<sender>";
+
+            }
+            case 3 -> {
+                return "<itemId|itemName|finish> [amount] [level]";
+            }
+            default -> {
+                Thread.dumpStack();
+                return "ERROR: invalid construction stage " + stage + ". Check console for stacktrace.";
+            }
+        }
+    }
+
+    public static class MailBuilder {
+        public int recipient;
+        public boolean sendToAll;
+        public int constructionStage;
+        public Mail mail;
+
+        public MailBuilder(int recipient, Mail mail) {
+            this.recipient = recipient;
+            this.sendToAll = false;
+            this.constructionStage = 0;
+            this.mail = mail;
+        }
+
+        public MailBuilder(boolean sendToAll, Mail mail) {
+            if (sendToAll) {
+                this.recipient = 0;
+                this.sendToAll = true;
+                this.constructionStage = 0;
+                this.mail = mail;
+            } else {
+                Grasscutter.getLogger().error("Please use MailBuilder(int, mail) when not sending to all");
+                Thread.dumpStack();
+            }
+        }
+    }
+}

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

@@ -3,7 +3,7 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -12,7 +12,7 @@ import java.util.List;
 public final class SendMessageCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (args.size() < 2) {
             CommandHandler.sendMessage(null, "Usage: sendmessage <player> <message>");
             return;
@@ -22,7 +22,7 @@ public final class SendMessageCommand implements CommandHandler {
             int target = Integer.parseInt(args.get(0));
             String message = String.join(" ", args.subList(1, args.size()));
 
-            GenshinPlayer targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
+            Player targetPlayer = Grasscutter.getGameServer().getPlayerByUid(target);
             if (targetPlayer == null) {
                 CommandHandler.sendMessage(sender, "Player not found.");
                 return;

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

@@ -4,9 +4,9 @@ import java.util.List;
 
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.data.GenshinData;
-import emu.grasscutter.game.GenshinPlayer;
-import emu.grasscutter.game.avatar.GenshinAvatar;
+import emu.grasscutter.data.GameData;
+import emu.grasscutter.game.avatar.Avatar;
+import emu.grasscutter.game.player.Player;
 import emu.grasscutter.server.packet.send.PacketAvatarFetterDataNotify;
 
 @Command(label = "setfetterlevel", usage = "setfetterlevel <level>",
@@ -15,7 +15,7 @@ import emu.grasscutter.server.packet.send.PacketAvatarFetterDataNotify;
 public final class SetFetterLevelCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (sender == null) {
             CommandHandler.sendMessage(null, "Run this command in-game.");
             return;
@@ -32,11 +32,11 @@ public final class SetFetterLevelCommand implements CommandHandler {
                 CommandHandler.sendMessage(sender, "Fetter level must be between 0 and 10.");
                 return;
             }
-            GenshinAvatar avatar = sender.getTeamManager().getCurrentAvatarEntity().getAvatar();
+            Avatar avatar = sender.getTeamManager().getCurrentAvatarEntity().getAvatar();
 
             avatar.setFetterLevel(fetterLevel);
             if (fetterLevel != 10) {
-                avatar.setFetterExp(GenshinData.getAvatarFetterLevelDataMap().get(fetterLevel).getExp());
+                avatar.setFetterExp(GameData.getAvatarFetterLevelDataMap().get(fetterLevel).getExp());
             }
 		    avatar.save();
 		

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

@@ -2,8 +2,8 @@ package emu.grasscutter.command.commands;
 
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
 import emu.grasscutter.game.entity.EntityAvatar;
+import emu.grasscutter.game.player.Player;
 import emu.grasscutter.game.props.FightProperty;
 import emu.grasscutter.server.packet.send.PacketEntityFightPropUpdateNotify;
 
@@ -14,7 +14,7 @@ import java.util.List;
 public final class SetStatsCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (sender == null) {
             CommandHandler.sendMessage(null, "Run this command in-game.");
             return;

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

@@ -2,7 +2,7 @@ package emu.grasscutter.command.commands;
 
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 import emu.grasscutter.game.props.PlayerProperty;
 
 import java.util.List;
@@ -13,7 +13,7 @@ import java.util.List;
 public final class SetWorldLevelCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (sender == null) {
             CommandHandler.sendMessage(null, "Run this command in-game.");
             return; // TODO: set player's world level from console or other players
@@ -29,7 +29,7 @@ public final class SetWorldLevelCommand implements CommandHandler {
 
             // Set in both world and player props
             sender.getWorld().setWorldLevel(level);
-            sender.setProperty(PlayerProperty.PROP_PLAYER_WORLD_LEVEL, level);
+            sender.setWorldLevel(level);
 
             sender.dropMessage("World level set to " + level + ".");
         } catch (NumberFormatException ignored) {

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

@@ -2,10 +2,10 @@ package emu.grasscutter.command.commands;
 
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.data.GenshinData;
+import emu.grasscutter.data.GameData;
 import emu.grasscutter.data.def.MonsterData;
-import emu.grasscutter.game.GenshinPlayer;
 import emu.grasscutter.game.entity.EntityMonster;
+import emu.grasscutter.game.player.Player;
 import emu.grasscutter.utils.Position;
 
 import java.util.List;
@@ -15,7 +15,7 @@ import java.util.List;
 public final class SpawnCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         if (sender == null) {
             CommandHandler.sendMessage(null, "Run this command in-game.");
             return;
@@ -31,7 +31,7 @@ public final class SpawnCommand implements CommandHandler {
             int level = args.size() > 1 ? Integer.parseInt(args.get(1)) : 1;
             int amount = args.size() > 2 ? Integer.parseInt(args.get(2)) : 1;
 
-            MonsterData entityData = GenshinData.getMonsterDataMap().get(entity);
+            MonsterData entityData = GameData.getMonsterDataMap().get(entity);
             if (entityData == null) {
                 CommandHandler.sendMessage(sender, "Invalid entity id.");
                 return;

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

@@ -3,7 +3,7 @@ package emu.grasscutter.command.commands;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.command.Command;
 import emu.grasscutter.command.CommandHandler;
-import emu.grasscutter.game.GenshinPlayer;
+import emu.grasscutter.game.player.Player;
 
 import java.util.List;
 
@@ -12,9 +12,9 @@ import java.util.List;
 public final class StopCommand implements CommandHandler {
 
     @Override
-    public void execute(GenshinPlayer sender, List<String> args) {
+    public void execute(Player sender, List<String> args) {
         CommandHandler.sendMessage(null, "Server shutting down...");
-        for (GenshinPlayer p : Grasscutter.getGameServer().getPlayers().values()) {
+        for (Player p : Grasscutter.getGameServer().getPlayers().values()) {
             CommandHandler.sendMessage(p, "Server shutting down...");
         }