/*
    * 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.shardingsphere.sqlfederation.optimizer.metadata.view;
  
  import lombok.RequiredArgsConstructor;
  import org.apache.calcite.plan.RelOptTable.ViewExpander;
  import org.apache.calcite.rel.RelRoot;
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.sql.SqlNode;
  import org.apache.calcite.sql2rel.SqlToRelConverter;
  import org.apache.shardingsphere.infra.database.core.type.DatabaseType;
  import org.apache.shardingsphere.infra.parser.sql.SQLStatementParserEngine;
  import org.apache.shardingsphere.parser.rule.SQLParserRule;
  import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
  import org.apache.shardingsphere.sqlfederation.optimizer.converter.SQLNodeConverterEngine;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.List;
  
  /**
   * ShardingSphere view expander.
   */
  @RequiredArgsConstructor
  public final class ShardingSphereViewExpander implements ViewExpander {
      
      private final SQLParserRule sqlParserRule;
      
      private final DatabaseType databaseType;
      
      private final SqlToRelConverter sqlToRelConverter;
      
      @Override
      public RelRoot expandView(final RelDataType rowType, final String queryString, final List<String> schemaPath, @Nullable final List<String> viewPath) {
          SQLStatement sqlStatement = new SQLStatementParserEngine(databaseType, sqlParserRule.getSqlStatementCache(),
                  sqlParserRule.getParseTreeCache()).parse(queryString, false);
          SqlNode sqlNode = SQLNodeConverterEngine.convert(sqlStatement);
          return sqlToRelConverter.convertQuery(sqlNode, true, true);
      }
  }