/*
 * 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.iotdb.db.queryengine.plan.relational.sql.parser;

import org.apache.iotdb.db.relational.grammar.sql.RelationalSqlLexer;
import org.apache.iotdb.db.relational.grammar.sql.RelationalSqlParser;

import java.util.concurrent.atomic.AtomicReference;
import java.util.function.BiConsumer;

public final class RefreshableSqlBaseParserInitializer
    implements BiConsumer<RelationalSqlLexer, RelationalSqlParser> {

  private final AtomicReference<SqlBaseParserAndLexerATNCaches> caches = new AtomicReference<>();

  public RefreshableSqlBaseParserInitializer() {
    refresh();
  }

  public void refresh() {
    caches.set(new SqlBaseParserAndLexerATNCaches());
  }

  @Override
  public void accept(RelationalSqlLexer lexer, RelationalSqlParser parser) {
    SqlBaseParserAndLexerATNCaches atnCaches = this.caches.get();
    atnCaches.lexer.configureLexer(lexer);
    atnCaches.parser.configureParser(parser);
  }

  private static final class SqlBaseParserAndLexerATNCaches {
    public final AntlrATNCacheFields lexer = new AntlrATNCacheFields(RelationalSqlLexer._ATN);
    public final AntlrATNCacheFields parser = new AntlrATNCacheFields(RelationalSqlParser._ATN);
  }
}
