Rewrite commands

Signed-off-by: Jaida Wu <mlgmxyysd@meowcat.org>

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

@@ -0,0 +1,36 @@
+package emu.grasscutter.command.commands;
+
+import emu.grasscutter.command.Command;
+import emu.grasscutter.command.CommandHandler;
+import emu.grasscutter.game.GenshinPlayer;
+
+import java.util.List;
+
+@Command(label = "changescene", usage = "changescene <scene id>",
+        description = "Changes your scene", aliases = {"scene"}, permission = "player.changescene")
+public class ChangeScene implements CommandHandler {
+    @Override
+    public void onCommand(GenshinPlayer sender, List<String> args) {
+        if (sender == null) {
+            CommandHandler.sendMessage(null, "Run this command in-game.");
+            return;
+        }
+
+        if (args.size() < 1) {
+            CommandHandler.sendMessage(sender, "Usage: changescene <scene id>");
+            return;
+        }
+
+        try {
+            int sceneId = Integer.parseInt(args.get(0));
+            boolean result = sender.getWorld().transferPlayerToScene(sender, sceneId, sender.getPos());
+
+            CommandHandler.sendMessage(sender, "Changed to scene " + sceneId);
+            if (!result) {
+                CommandHandler.sendMessage(sender, "Scene does not exist or you are already in it");
+            }
+        } catch (Exception e) {
+            CommandHandler.sendMessage(sender, "Usage: changescene <scene id>");
+        }
+    }
+}