content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.kafka.connect.transforms;
  
  import org.apache.kafka.common.config.ConfigDef;
  import org.apache.kafka.common.utils.AppInfoParser;
  import org.apache.kafka.connect.components.Versioned;
  import org.apache.kafka.connect.connector.ConnectRecord;
  import org.apache.kafka.connect.transforms.util.RegexValidator;
  import org.apache.kafka.connect.transforms.util.SimpleConfig;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Map;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  public class RegexRouter<R extends ConnectRecord<R>> implements Transformation<R>, Versioned {
  
      private static final Logger log = LoggerFactory.getLogger(RegexRouter.class);
  
      public static final String OVERVIEW_DOC = "Update the record topic using the configured regular expression and replacement string."
              + "<p/>Under the hood, the regex is compiled to a <code>java.util.regex.Pattern</code>. "
              + "If the pattern matches the input topic, <code>java.util.regex.Matcher#replaceFirst()</code> is used with the replacement string to obtain the new topic.";
  
      public static final ConfigDef CONFIG_DEF = new ConfigDef()
              .define(ConfigName.REGEX, ConfigDef.Type.STRING, ConfigDef.NO_DEFAULT_VALUE, new RegexValidator(), ConfigDef.Importance.HIGH,
                      "Regular expression to use for matching.")
              .define(ConfigName.REPLACEMENT, ConfigDef.Type.STRING, ConfigDef.NO_DEFAULT_VALUE, ConfigDef.Importance.HIGH,
                      "Replacement string.");
  
      private interface ConfigName {
          String REGEX = "regex";
          String REPLACEMENT = "replacement";
      }
  
      private Pattern regex;
      private String replacement;
  
      @Override
      public String version() {
          return AppInfoParser.getVersion();
      }
  
      @Override
      public void configure(Map<String, ?> props) {
          final SimpleConfig config = new SimpleConfig(CONFIG_DEF, props);
          regex = Pattern.compile(config.getString(ConfigName.REGEX));
          replacement = config.getString(ConfigName.REPLACEMENT);
      }
  
      @Override
      public R apply(R record) {
          final Matcher matcher = regex.matcher(record.topic());
          if (matcher.matches()) {
              final String topic = matcher.replaceFirst(replacement);
              log.trace("Rerouting from topic '{}' to new topic '{}'", record.topic(), topic);
              return record.newRecord(topic, record.kafkaPartition(), record.keySchema(), record.key(), record.valueSchema(), record.value(), record.timestamp());
          } else {
              log.trace("Not rerouting topic '{}' as it does not match the configured regex", record.topic());
          }
          return record;
      }
  
      @Override
      public void close() {
      }
  
      @Override
      public ConfigDef config() {
          return CONFIG_DEF;
      }
  
  }
  