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.beam.it.elasticsearch;
  
  import static org.apache.beam.it.common.utils.ResourceManagerUtils.generateResourceId;
  
  import java.time.format.DateTimeFormatter;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /** Utilities for {@link ElasticsearchResourceManager} implementations. */
  final class ElasticsearchUtils {
  
    // Constraints from
    // https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-create-index.html
    private static final int MAX_INDEX_NAME_LENGTH = 255;
  
    // Cannot include \, /, *, ?, ", <, >, |, ` ` (space character), ,, #
    private static final Pattern ILLEGAL_INDEX_NAME_CHARS = Pattern.compile("[/\\\\ \"?*<>|,#\0]");
    private static final String REPLACE_INDEX_NAME_CHAR = "-";
    private static final DateTimeFormatter TIME_FORMAT =
        DateTimeFormatter.ofPattern("yyyyMMdd-HHmmss-SSSSSS");
  
    private ElasticsearchUtils() {}
  
    /**
     * Generates an Elasticsearch index name from a given string.
     *
     * @param baseString The string to generate the name from.
     * @return The database name string.
     */
    static String generateIndexName(String baseString) {
      return generateResourceId(
          baseString,
          ILLEGAL_INDEX_NAME_CHARS,
          REPLACE_INDEX_NAME_CHAR,
          MAX_INDEX_NAME_LENGTH,
          TIME_FORMAT);
    }
  
    /**
     * Checks whether the given index name is valid according to Elasticsearch constraints.
     *
     * @param indexName the index name to check.
     * @throws IllegalArgumentException if the index name is invalid.
     */
    static void checkValidIndexName(String indexName) {
      if (indexName.length() > MAX_INDEX_NAME_LENGTH) {
        throw new IllegalArgumentException(
            "Index name "
                + indexName
                + " cannot be longer than "
                + MAX_INDEX_NAME_LENGTH
                + " characters.");
      }
      Matcher matcher = ILLEGAL_INDEX_NAME_CHARS.matcher(indexName);
      if (matcher.find()) {
        throw new IllegalArgumentException(
            "Index name "
                + indexName
                + " is not a valid name. Character \""
                + matcher.group()
                + "\" is not allowed.");
      }
      if (indexName.charAt(0) == '-' || indexName.charAt(0) == '_' || indexName.charAt(0) == '+') {
        throw new IllegalArgumentException(
            "Index name " + indexName + " can not start with -, _ or +.");
      }
    }
  }
  