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.sql.misc;
  
  import static java.util.Objects.requireNonNull;
  
  import au.csiro.pathling.fhirpath.encoding.CodingSchema;
  import au.csiro.pathling.fhirpath.literal.CodingLiteral;
  import au.csiro.pathling.sql.udf.SqlFunction1;
  import jakarta.annotation.Nullable;
  import java.io.Serial;
  import org.apache.spark.sql.Row;
  import org.apache.spark.sql.types.DataType;
  import org.apache.spark.sql.types.DataTypes;
  import org.hl7.fhir.r4.model.Coding;
  
  /**
   * Spark UDF to convert a Coding struct to a valid Coding literal string.
   *
   * @author John Grimes
   */
  public class CodingToLiteral implements SqlFunction1<Row, String> {
  
    /**
     * The name of this function when used within SQL.
     */
    public static final String FUNCTION_NAME = "coding_to_literal";
  
    @Serial
    private static final long serialVersionUID = 1L;
  
    @Override
    public String getName() {
      return FUNCTION_NAME;
    }
  
    @Override
    public DataType getReturnType() {
      return DataTypes.StringType;
    }
  
    @Override
    @Nullable
    public String call(@Nullable final Row row) {
      if (row == null) {
        return null;
      }
      final Coding coding = requireNonNull(CodingSchema.decode(row));
      return CodingLiteral.toLiteral(coding);
    }
  
  }
  