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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.variable;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.commons.lang3.StringUtils;
import com.google.common.collect.ImmutableMap;
import io.github.linuxforhealth.api.EvaluationResult;
import io.github.linuxforhealth.api.InputDataExtractor;
import io.github.linuxforhealth.api.Specification;
import io.github.linuxforhealth.api.Variable;
import io.github.linuxforhealth.core.expression.VariableUtils;
import io.github.linuxforhealth.hl7.expression.specification.SpecificationParser;


/**
 * Defines Variable object that can be used during the expression evaluation.
 * 
 *
 * @author pbhallam
 */
public class SimpleVariable implements Variable {
  public static final String OBJECT_TYPE = Object.class.getSimpleName();

  private String name;
  private List spec;
  private boolean extractMultiple;

  public SimpleVariable(String name, List spec) {
    this(name, spec, false);
  }

  public SimpleVariable(String name, List spec, boolean extractMultiple) {
    this.name = name;
    this.spec = new ArrayList<>();
    if (spec != null && !spec.isEmpty()) {
      this.spec.addAll(spec);
    }
    this.extractMultiple = extractMultiple;
  }

  public List getSpec() {
    return new ArrayList<>(spec);
  }

  public String getType() {
    return OBJECT_TYPE;
  }


  public String getName() {
    return name;
  }





  // resolve variable value

  public EvaluationResult extractVariableValue(Map contextValues,
      InputDataExtractor dataSource) {
    EvaluationResult result;
    if (!this.spec.isEmpty()) {
      result = getValueFromSpecs(contextValues, dataSource);
    } else {
      result = null;
    }

    return result;

  }


  protected EvaluationResult getValueFromSpecs(Map contextValues,
      InputDataExtractor dataSource) {
    EvaluationResult fetchedValue = null;
    for (String specValue : this.spec) {
      if (VariableUtils.isVar(specValue)) {
        fetchedValue =
            getVariableValueFromVariableContextMap(specValue, ImmutableMap.copyOf(contextValues));
      } else {
        EvaluationResult gen;
        Specification hl7spec = SpecificationParser.parse(specValue, this.extractMultiple, false);

        gen = hl7spec.extractValueForSpec(dataSource, contextValues);

        if (gen != null && !gen.isEmpty()) {
          fetchedValue = gen;
      }
    }
      // break the loop and return
      if (fetchedValue != null) {
        return fetchedValue;
      }

  }
    return fetchedValue;
  }


  private static EvaluationResult getVariableValueFromVariableContextMap(String varName,
      ImmutableMap contextValues) {
    if (StringUtils.isNotBlank(varName)) {
      EvaluationResult fetchedValue;
      fetchedValue = contextValues.get(VariableUtils.getVarName(varName));

      return fetchedValue;
    } else {
      return null;
    }
  }




  @Override
  public String getVariableName() {
    return VariableUtils.getVarName(this.name);
  }

  /**
   * Return if variable value should extracted from all repetitions of the spec
   * 
   * @return boolean
   */
  public boolean extractMultiple() {
    return this.extractMultiple;
  }


}