Rename level field to avoid ES type collision

import org.graylog2.plugin.Message
import java.util.regex.Matcher
import java.util.regex.Pattern
rule "Rename level field to avoid ES type collision"
  when
      m : Message( message matches ".*level=.*" );
  then
      Matcher matcher = Pattern.compile("level=(\\w+)(\\s|$)").matcher(m.getMessage());
      if (matcher.find()) {
        String x = matcher.group(1);
        if(x.equals("debug")) {
          m.addField("level", 7);
        } else if(x.equals("info")) {
          m.addField("level", 6);
        } else if(x.equals("notice")) {
          m.addField("level", 5);
        } else if(x.equals("warning")) {
          m.addField("level", 4);
        } else if(x.equals("error")) {
          m.addField("level", 3);
        } else if(x.equals("critical")) {
          m.addField("level", 2);
        } else if(x.equals("alert")) {
          m.addField("level", 1);
        } else if(x.equals("emergency")) {
          m.addField("level", 0);
        } else {
          m.addField("level", 6);
        }
      }
end