add code

src/main/java/sh/okx/rankup/messages/Variable.java

@@ -0,0 +1,31 @@
+package sh.okx.rankup.messages;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public enum Variable {
+  PLAYER,
+  OLD_RANK,
+  OLD_RANK_NAME,
+  RANK,
+  RANK_NAME,
+  MONEY,
+  MONEY_NEEDED,
+  PERCENT_DONE,
+  PERCENT_LEFT;
+
+  public static Variable getVariable(String name) {
+    for(Variable variable : values()) {
+      if(variable.toString().equalsIgnoreCase(name)) {
+        return variable;
+      }
+    }
+    return null;
+  }
+
+  public String replace(String message, String value) {
+    Pattern pattern = Pattern.compile("\\{" + this + "}", Pattern.CASE_INSENSITIVE);
+    Matcher matcher = pattern.matcher(message);
+    return matcher.replaceAll(value);
+  }
+}