content: /*
   * Copyright [2024] [name of copyright owner]
   *
   * 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.aliyun.fastmodel.transform.flink.parser.util;
  
  import java.util.HashSet;
  import java.util.Set;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import com.aliyun.fastmodel.transform.flink.parser.FlinkSqlParser;
  import com.google.common.base.Strings;
  import org.antlr.v4.runtime.Vocabulary;
  
  /**
   * @author 子梁
   * @date 2024/9/11
   */
  public class FlinkReservedWordUtil {
  
      private static final Pattern KW_IDENTIFIER = Pattern.compile("(KW_)([A-Z0-9_]+)");
  
      private static final Set<String> SET = new HashSet<>();
  
      static {
          Vocabulary vocabulary = FlinkSqlParser.VOCABULARY;
          for (int i = 0; i <= vocabulary.getMaxTokenType(); i++) {
              String name = Strings.nullToEmpty(vocabulary.getSymbolicName(i));
              Matcher matcher = KW_IDENTIFIER.matcher(name);
              if (matcher.matches()) {
                  SET.add(matcher.group(2));
              }
          }
      }
  
      public static boolean isReservedKeyWord(String word) {
          return SET.contains(word.toUpperCase());
      }
  
  }
  