content: /*
   * Copyright © 2018-2025 Commonwealth Scientific and Industrial Research
   * Organisation (CSIRO) ABN 41 687 119 230.
   *
   * 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 au.csiro.pathling.projection;
  
  import au.csiro.pathling.fhirpath.FhirPath;
  import jakarta.annotation.Nonnull;
  import java.util.Optional;
  import org.apache.spark.sql.types.DataType;
  import org.hl7.fhir.r4.model.Enumerations.FHIRDefinedType;
  
  /**
   * Information about a column that has been requested to be included in a projection.
   * <p>
   * Includes the parsed {@link FhirPath}, the name of the column and whether the column has been
   * asserted to be a collection.
   *
   * @param path The parsed FHIRPath expression that defines the column.
   * @param name The requested name of the column.
   * @param collection Whether the column has been asserted to be a collection.
   * @param type The type that has been asserted for the column.
   * @param sqlType The SQL type that has been asserted for the column.
   */
  public record RequestedColumn(
      @Nonnull FhirPath path,
      @Nonnull String name,
      boolean collection,
      @Nonnull Optional<FHIRDefinedType> type,
      @Nonnull Optional<DataType> sqlType
  ) {
  
    @Nonnull
    @Override
    public String toString() {
      return "RequestedColumn{" +
          "path=" + path +
          ", name='" + name + '\'' +
          ", collection=" + collection +
          ", type=" + type +
          ", sqlType=" + sqlType +
          '}';
    }
  
    /**
     * Returns a string expression representation of this requested column.
     *
     * @return the string expression representation
     */
    @Nonnull
    public String toExpression() {
      return (collection
              ? "many"
              : "one") + ": " + path.toExpression() + " as " + name;
    }
  }
  