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.calcite.adapter.file;
  
  import org.apache.calcite.model.ModelHandler;
  import org.apache.calcite.schema.Schema;
  import org.apache.calcite.schema.SchemaFactory;
  import org.apache.calcite.schema.SchemaPlus;
  
  import java.io.File;
  import java.util.List;
  import java.util.Map;
  
  /**
   * Factory that creates a {@link FileSchema}.
   *
   * <p>Allows a custom schema to be included in a model.json file.
   * See <a href="http://calcite.apache.org/docs/file_adapter.html">File adapter</a>.
   */
  @SuppressWarnings("UnusedDeclaration")
  public class FileSchemaFactory implements SchemaFactory {
    /** Public singleton, per factory contract. */
    public static final FileSchemaFactory INSTANCE = new FileSchemaFactory();
  
    /** Name of the column that is implicitly created in a CSV stream table
     * to hold the data arrival time. */
    static final String ROWTIME_COLUMN_NAME = "ROWTIME";
  
    private FileSchemaFactory() {
    }
  
    @Override public Schema create(SchemaPlus parentSchema, String name,
        Map<String, Object> operand) {
      @SuppressWarnings("unchecked") List<Map<String, Object>> tables =
          (List) operand.get("tables");
      final File baseDirectory =
          (File) operand.get(ModelHandler.ExtraOperand.BASE_DIRECTORY.camelName);
      final String directory = (String) operand.get("directory");
      File directoryFile = null;
      if (directory != null) {
        directoryFile = new File(directory);
      }
      if (baseDirectory != null) {
        if (directoryFile == null) {
          directoryFile = baseDirectory;
        } else if (!directoryFile.isAbsolute()) {
          directoryFile = new File(baseDirectory, directory);
        }
      }
      return new FileSchema(parentSchema, name, directoryFile, tables);
    }
  }
  