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

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FHIR converter is a Java based library that enables converting Hl7v2 messages to FHIR resources
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/*
 * (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.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import io.github.linuxforhealth.api.EvaluationResult;
import io.github.linuxforhealth.api.Expression;
import io.github.linuxforhealth.api.InputDataExtractor;
import io.github.linuxforhealth.api.ResourceValue;
import io.github.linuxforhealth.api.Specification;
import io.github.linuxforhealth.api.Variable;
import io.github.linuxforhealth.core.Constants;
import io.github.linuxforhealth.core.data.DataTypeUtil;
import io.github.linuxforhealth.core.exception.DataExtractionException;
import io.github.linuxforhealth.core.exception.RequiredConstraintFailureException;
import io.github.linuxforhealth.core.expression.EmptyEvaluationResult;
import io.github.linuxforhealth.core.expression.EvaluationResultFactory;
import io.github.linuxforhealth.core.expression.VariableUtils;
import io.github.linuxforhealth.hl7.expression.specification.SpecificationUtil;

public abstract class AbstractExpression implements Expression {
    private static final String RESOURCE = "Resource";

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

    private ExpressionAttributes attr;
    private String originalContext;
    private boolean conditionSatisfiedState;

    public AbstractExpression(ExpressionAttributes attr) {
        this.attr = attr;
    }

    @Override
    public String getType() {
        return this.attr.getType();
    }

    public ExpressionAttributes getExpressionAttr() {
        return this.attr;
    }

    @Override
    public boolean isEvaluateLater() {
        return this.attr.isEvaluateLater();

    }

    @Override
    public EvaluationResult getDefaultValue() {
        return EvaluationResultFactory.getEvaluationResult(this.attr.getDefaultValue());
    }

    public boolean isRequired() {
        return this.attr.isRequired();
    }

    @Override
    public List getspecs() {
        return this.attr.getSpecs();
    }

    @Override
    public List getVariables() {
        return this.attr.getVariables();
    }

    /**
     * Evaluates the expression and generated single or multiple resources based on the expression
     * values. If expression (reference and resource) ends with * then for that expression the Generic
     * result includes list of values.
     * 
     * @see io.github.linuxforhealth.api.Expression#evaluate(io.github.linuxforhealth.api.InputDataExtractor,
     *      java.util.Map, EvaluationResult)
     */
    @Override
    public EvaluationResult evaluate(InputDataExtractor dataSource,
            Map contextValues, EvaluationResult baseValue) {
        Preconditions.checkArgument(dataSource != null, "dataSource cannot be null");
        Preconditions.checkArgument(contextValues != null, "contextValues cannot be null");
        Preconditions.checkArgument(baseValue != null, "baseValue cannot be null");
        EvaluationResult result;
        try {
            setLoggingContext();

            

            Map localContextValues = new HashMap<>(contextValues);

            if (!baseValue.isEmpty()) {
                localContextValues.put(baseValue.getIdentifier(), baseValue);
                localContextValues.put(Constants.BASE_VALUE_NAME, baseValue);
            }

            result = evaluateValueOfExpression(dataSource, localContextValues, baseValue);

            

            if (this.conditionSatisfiedState && this.isRequired()
                    && (result == null || result.isEmpty())) {

                String stringRep = this.toString();
                throw new RequiredConstraintFailureException(
                        "Resource Constraint condition not satisfied for expression   :" + stringRep);

            } else {
                return result;
            }
        } catch (DataExtractionException | IllegalArgumentException e) {
            LOGGER.warn("Failure encountered during evaluation of expression {}",
                    this.attr.getName());
            return null;
        } finally {
            resetLoggingContext();
        }
    }

    private void setLoggingContext() {
        originalContext = MDC.get(RESOURCE);
        MDC.put(RESOURCE, originalContext + "-> Field:" + this.getExpressionAttr().getName());
    }

    private void resetLoggingContext() {
        MDC.put(RESOURCE, originalContext);
    }

    private EvaluationResult evaluateValueOfExpression(InputDataExtractor dataSource,
            Map localContextValues, EvaluationResult baseinputValue) {
        /**
         * Steps:
         * 
         * Add all constants to the context map
         * Evaluate the specs
         * Evaluate the variables
         * Apply the condition
         * If condition is satisfies then evaluate the valueOf/value attribute.
         * 
         * Note: If generateMultiple is set that all the spec values are used for generating list value
         * from the expression.
         * 
         */

        // Add constants to the context map
        this.attr.getConstants().entrySet().forEach(e -> localContextValues.put(e.getKey(),
                EvaluationResultFactory.getEvaluationResult(e.getValue())));

        List