io.github.linuxforhealth.hl7.expression.ReferenceExpression Maven / Gradle / Ivy

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FHIR converter is a Java based library that enables converting Hl7v2 messages to FHIR resources
There is a newer version: 1.0.19
/*
 * (C) Copyright IBM Corp. 2020
 *
 * SPDX-License-Identifier: Apache-2.0
 */
package io.github.linuxforhealth.hl7.expression;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import io.github.linuxforhealth.api.EvaluationResult;
import io.github.linuxforhealth.api.InputDataExtractor;
import io.github.linuxforhealth.api.ResourceValue;
import io.github.linuxforhealth.core.expression.EvaluationResultFactory;
import io.github.linuxforhealth.core.resource.ResourceResult;
import io.github.linuxforhealth.hl7.resource.HL7DataBasedResourceModel;
import io.github.linuxforhealth.hl7.resource.ResourceReader;

/**
 * Represent a expression that represents resolving a json template and creating a reference data
 * type.
 * 
 *
 * @author {user}
 */
@JsonIgnoreProperties(ignoreUnknown = true)
public class ReferenceExpression extends AbstractExpression {


  private static final Logger LOGGER = LoggerFactory.getLogger(ReferenceExpression.class);

  private HL7DataBasedResourceModel data;
  private HL7DataBasedResourceModel referenceModel = (HL7DataBasedResourceModel) ResourceReader
      .getInstance().generateResourceModel("datatype/Reference");
  private String reference;

  @JsonCreator
  public ReferenceExpression(ExpressionAttributes expAttr) {
    super(expAttr);

    this.reference = expAttr.getValueOf();
    this.data = (HL7DataBasedResourceModel) ResourceReader.getInstance()
        .generateResourceModel(this.reference);
    Preconditions.checkState(this.data != null, "Resource reference model cannot be null");
  }



  @Override
  public EvaluationResult evaluateExpression(InputDataExtractor dataSource,
      Map contextValues, EvaluationResult baseValue) {
    Preconditions.checkArgument(dataSource != null, "dataSource cannot be null");
    Preconditions.checkArgument(contextValues != null, "contextValues cannot be null");
    
    EvaluationResult resourceReferenceResult = null;
    // Evaluate the resource first and add it to the list of additional resources generated
    ResourceResult primaryResourceResult = evaluateResource(dataSource, contextValues, baseValue);
    // If the primary resource is generated then create the reference
    if (primaryResourceResult != null && primaryResourceResult.getValue() != null) {
      List additionalResources = new ArrayList<>();
      additionalResources.addAll(primaryResourceResult.getAdditionalResources());
      additionalResources.add(primaryResourceResult.getValue());


      EvaluationResult genBaseValue = EvaluationResultFactory
          .getEvaluationResult(primaryResourceResult.getValue().getResource());

      Map localContextValues = new HashMap<>(contextValues);

      ResourceResult result = this.referenceModel.evaluate(dataSource,
          ImmutableMap.copyOf(localContextValues), genBaseValue);
      if (result != null && result.getValue() != null) {
        ResourceValue resolvedvalues = result.getValue();

        
        if (resolvedvalues != null) {
          resourceReferenceResult = EvaluationResultFactory
              .getEvaluationResult(resolvedvalues.getResource(), additionalResources);
        }
      }
    }

    return resourceReferenceResult;

  }



  private ResourceResult evaluateResource(InputDataExtractor dataSource,
      Map contextValues, EvaluationResult hl7SpecValue) {
    ResourceResult result =
        this.data.evaluate(dataSource, ImmutableMap.copyOf(contextValues), hl7SpecValue);
    if (result != null && result.getValue() != null) {
      return result;
    }
    return null;

  }



  public String getReference() {
    return this.reference;
  }



}