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.terminology;
  
  import ca.uhn.fhir.rest.gclient.IOperationUntypedWithInput;
  import jakarta.annotation.Nonnull;
  import java.util.Optional;
  
  
  /**
   * An abstraction of a terminology operation that describes how to validate, execute and extract a
   * result from the response.
   *
   * @param <R> The type of the response returned by the terminology client
   * @param <T> The type of the final result that is extracted from the response
   * @author John Grimes
   */
  public interface TerminologyOperation<R, T> {
  
    /**
     * Validates the parameters for this operation.
     *
     * @return An empty {@link Optional} if the parameters are valid, or an {@link Optional}
     * containing the result to be returned to the user if the parameters are invalid.
     */
    @Nonnull
    Optional<T> validate();
  
    /**
     * Builds a request for this operation, ready to send to the terminology server.
     *
     * @return A request for this operation that has not been executed yet, and can still be modified
     * (e.g. headers)
     */
    @Nonnull
    IOperationUntypedWithInput<R> buildRequest();
  
    /**
     * Extracts the result from the response from the terminology server.
     *
     * @param response the response from the terminology server
     * @return the extracted result
     */
    @Nonnull
    T extractResult(@Nonnull final R response);
  
    /**
     * @return the result that should be returned to the user if the terminology server returns a 400
     * series response
     */
    @Nonnull
    T invalidRequestFallback();
  
  }
  