content: /*
   * Copyright 2024 Copyright 2022 Aiven Oy and
   * bigquery-connector-for-apache-kafka project contributors
   *
   * This software contains code derived from the Confluent BigQuery
   * Kafka Connector, Copyright Confluent, Inc, which in turn
   * contains code derived from the WePay BigQuery Kafka Connector,
   * Copyright WePay, Inc.
   *
   * Licensed 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 com.wepay.kafka.connect.bigquery.utils;
  
  import java.util.HashMap;
  import java.util.Map;
  
  public class FieldNameSanitizer {
  
    // Replace all non-letter, non-digit characters with underscore. Append underscore in front of
    // name if it does not begin with alphabet or underscore.
    public static String sanitizeName(String name) {
      String sanitizedName = name.replaceAll("[^a-zA-Z0-9_]", "_");
      if (sanitizedName.matches("^[^a-zA-Z_].*")) {
        sanitizedName = "_" + sanitizedName;
      }
      return sanitizedName;
    }
  
  
    // Big Query specifies field name must begin with a alphabet or underscore and can only contain
    // letters, numbers, and underscores.
    // Note: a.b and a/b will have the same value after sanitization which will cause Duplicate key
    // Exception.
    @SuppressWarnings("unchecked")
    public static Map<String, Object> replaceInvalidKeys(Map<String, Object> map) {
      Map<String, Object> result = new HashMap<>();
      map.forEach((key, value) -> {
        String sanitizedKey = sanitizeName(key);
        if (value instanceof Map) {
          result.put(sanitizedKey, replaceInvalidKeys((Map<String, Object>) value));
        } else {
          result.put(sanitizedKey, value);
        }
      });
      return result;
    }
  }
  