Add warnings for using %player% without using the UUID config setting. (

#6271)

* Update VariableString.java

* messed up imports

* Catch offline players

src/main/java/ch/njol/skript/lang/VariableString.java

@@ -18,21 +18,8 @@
  */
 package ch.njol.skript.lang;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.List;
-import java.util.stream.Collectors;
-
-import org.bukkit.ChatColor;
-import org.bukkit.event.Event;
-import org.eclipse.jdt.annotation.Nullable;
-import org.jetbrains.annotations.NotNull;
-import org.skriptlang.skript.lang.script.Script;
-
-import com.google.common.collect.Lists;
-
 import ch.njol.skript.Skript;
+import ch.njol.skript.SkriptConfig;
 import ch.njol.skript.classes.Changer.ChangeMode;
 import ch.njol.skript.classes.ClassInfo;
 import ch.njol.skript.expressions.ExprColoured;
@@ -54,6 +41,19 @@
 import ch.njol.util.StringUtils;
 import ch.njol.util.coll.CollectionUtils;
 import ch.njol.util.coll.iterator.SingleItemIterator;
+import com.google.common.collect.Lists;
+import org.bukkit.ChatColor;
+import org.bukkit.OfflinePlayer;
+import org.bukkit.event.Event;
+import org.eclipse.jdt.annotation.Nullable;
+import org.jetbrains.annotations.NotNull;
+import org.skriptlang.skript.lang.script.Script;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.stream.Collectors;
 
 /**
  * Represents a string that may contain expressions, and is thus "variable".
@@ -229,6 +229,12 @@ public static VariableString newInstance(String orig, StringMode mode) {
 							log.printErrors("Can't understand this expression: " + s.substring(c + 1, c2));
 							return null;
 						} else {
+							if (!SkriptConfig.usePlayerUUIDsInVariableNames.value() && OfflinePlayer.class.isAssignableFrom(expr.getReturnType())) {
+								Skript.warning(
+										"In the future, players in variable names will use the player's UUID instead of their name. " +
+										"For information on how to make sure your scripts won't be impacted by this change, see https://github.com/SkriptLang/Skript/discussions/6270."
+								);
+							}
 							string.add(expr);
 						}
 						log.printLog();