content: /*
   * This is a modified version of the Bunsen library, originally published at
   * https://github.com/cerner/bunsen.
   *
   * Bunsen is copyright 2017 Cerner Innovation, Inc., and is licensed under
   * the Apache License, version 2.0 (http://www.apache.org/licenses/LICENSE-2.0).
   *
   * These modifications are 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.support.r4;
  
  import au.csiro.pathling.support.FhirConversionSupport;
  import jakarta.annotation.Nonnull;
  import java.io.Serial;
  import java.util.List;
  import java.util.stream.Collectors;
  import org.hl7.fhir.instance.model.api.IBase;
  import org.hl7.fhir.instance.model.api.IBaseBundle;
  import org.hl7.fhir.instance.model.api.IBaseResource;
  import org.hl7.fhir.r4.model.Base;
  import org.hl7.fhir.r4.model.Bundle;
  import org.hl7.fhir.r4.model.Bundle.BundleEntryComponent;
  import org.hl7.fhir.r4.model.Reference;
  import org.hl7.fhir.r4.model.Resource;
  
  /**
   * {@link FhirConversionSupport} implementation for FHIR R4.
   */
  public class R4FhirConversionSupport extends FhirConversionSupport {
  
    @Serial
    private static final long serialVersionUID = -367070946615790595L;
  
    @Override
    public String fhirType(final IBase base) {
  
      return base.fhirType();
    }
  
    /**
     * {@inheritDoc}
     */
    @Override
    @Nonnull
    public <T extends IBaseResource> List<IBaseResource> extractEntryFromBundle(
        @Nonnull final IBaseBundle bundle,
        @Nonnull final Class<T> resourceClass) {
      final Bundle r4Bundle = (Bundle) bundle;
  
      return r4Bundle.getEntry().stream()
          .map(BundleEntryComponent::getResource)
          .filter(resourceClass::isInstance)
          .collect(Collectors.toList());
    }
  
    private static boolean isURNReference(@Nonnull final Reference reference) {
      return reference.hasReference() && reference.getReference().startsWith("urn:");
    }
  
    static void resolveURNReference(@Nonnull final Base base) {
      if (base instanceof final Reference reference) {
        final Resource resource = (Resource) reference.getResource();
        if (isURNReference(reference) && resource != null && resource.hasIdElement()) {
          reference.setReference(resource.getIdElement().getValue());
        }
      }
    }
  
    private static void resolveURNReferences(@Nonnull final Resource resource) {
      FhirTraversal.processRecursive(resource, R4FhirConversionSupport::resolveURNReference);
    }
  
    /**
     * {@inheritDoc}
     */
    @Nonnull
    @Override
    public IBaseBundle resolveReferences(@Nonnull final IBaseBundle bundle) {
      final Bundle r4Bundle = (Bundle) bundle;
      r4Bundle.getEntry().stream()
          .map(Bundle.BundleEntryComponent::getResource)
          .forEach(R4FhirConversionSupport::resolveURNReferences);
      return r4Bundle;
    }
  
  }
  