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.sdk.extensions.sql.impl.parser;
  
  import static org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.util.Static.RESOURCE;
  
  import java.util.List;
  import org.apache.beam.sdk.extensions.sql.impl.BeamCalciteSchema;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.jdbc.CalcitePrepare;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.jdbc.CalciteSchema;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlDrop;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlIdentifier;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlNode;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlOperator;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlUtil;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlWriter;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.parser.SqlParserPos;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList;
  
  /**
   * Base class for parse trees of {@code DROP TABLE}, {@code DROP VIEW} and {@code DROP MATERIALIZED
   * VIEW} statements.
   */
  abstract class SqlDropObject extends SqlDrop implements BeamSqlParser.ExecutableStatement {
    protected final SqlIdentifier name;
  
    /** Creates a SqlDropObject. */
    SqlDropObject(SqlOperator operator, SqlParserPos pos, boolean ifExists, SqlIdentifier name) {
      super(operator, pos, ifExists);
      this.name = name;
    }
  
    @Override
    public List<SqlNode> getOperandList() {
      return ImmutableList.<SqlNode>of(name);
    }
  
    @Override
    public void unparse(SqlWriter writer, int leftPrec, int rightPrec) {
      writer.keyword(getOperator().getName()); // "DROP TABLE" etc.
      if (ifExists) {
        writer.keyword("IF EXISTS");
      }
      name.unparse(writer, leftPrec, rightPrec);
    }
  
    @Override
    public void execute(CalcitePrepare.Context context) {
      final List<String> path = context.getDefaultSchemaPath();
      CalciteSchema schema = context.getRootSchema();
      for (String p : path) {
        schema = schema.getSubSchema(p, true);
        if (schema == null) {
          throw new AssertionError(String.format("Got null sub-schema for path '%s' in %s", p, path));
        }
      }
      final boolean existed;
      switch (getKind()) {
        case DROP_TABLE:
          if (schema.schema instanceof BeamCalciteSchema) {
            BeamCalciteSchema beamSchema = (BeamCalciteSchema) schema.schema;
            beamSchema.getTableProvider().dropTable(name.getSimple());
            existed = true;
          } else {
            existed = schema.removeTable(name.getSimple());
          }
          if (!existed && !ifExists) {
            throw SqlUtil.newContextException(
                name.getParserPosition(), RESOURCE.tableNotFound(name.getSimple()));
          }
          break;
        default:
          throw new AssertionError(getKind());
      }
    }
  }
  
  // End SqlDropObject.java
  