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.clickhouse;
  
  import java.util.regex.Pattern;
  
  /** Utilities for {@link ClickHouseResourceManager} implementations. */
  public class ClickHouseUtils {
  
    // ClickHouse max table name length
    private static final int MAX_TABLE_NAME_LENGTH = 206;
  
    // ClickHouse table name restrictions:
    // - Must not contain '.', '/', '\\', ' ', ',', '`'
    // - Must start with a letter or an underscore
    private static final Pattern VALID_TABLE_NAME_PATTERN =
        Pattern.compile("^[a-zA-Z_][a-zA-Z0-9_]*$");
  
    private ClickHouseUtils() {}
  
    /**
     * Checks whether the given table name is valid according to ClickHouse constraints.
     *
     * @param tableName the table name to check.
     * @throws ClickHouseResourceManagerException if the table name is invalid.
     */
    static void checkValidTableName(String tableName) {
      if (tableName.length() > MAX_TABLE_NAME_LENGTH) {
        throw new IllegalArgumentException(
            "Table name "
                + tableName
                + " cannot be longer than "
                + MAX_TABLE_NAME_LENGTH
                + " characters.");
      }
      if (!VALID_TABLE_NAME_PATTERN.matcher(tableName).matches()) {
        throw new IllegalArgumentException(
            "Table name "
                + tableName
                + " is not valid. It must contain only letters, numbers, and underscores and must start with a letter or an underscore.");
      }
    }
  }
  