001package org.hl7.fhir.r4.hapi.fluentpath;
002
003import ca.uhn.fhir.context.FhirContext;
004import ca.uhn.fhir.context.support.IValidationSupport;
005import ca.uhn.fhir.fhirpath.FhirPathExecutionException;
006import ca.uhn.fhir.fhirpath.IFhirPath;
007import ca.uhn.fhir.fhirpath.IFhirPathEvaluationContext;
008import ca.uhn.fhir.i18n.Msg;
009import jakarta.annotation.Nonnull;
010import org.hl7.fhir.exceptions.FHIRException;
011import org.hl7.fhir.exceptions.PathEngineException;
012import org.hl7.fhir.instance.model.api.IBase;
013import org.hl7.fhir.r4.hapi.ctx.HapiWorkerContext;
014import org.hl7.fhir.r4.model.Base;
015import org.hl7.fhir.r4.model.ExpressionNode;
016import org.hl7.fhir.r4.model.IdType;
017import org.hl7.fhir.r4.model.TypeDetails;
018import org.hl7.fhir.r4.model.ValueSet;
019import org.hl7.fhir.r4.utils.FHIRPathEngine;
020import org.hl7.fhir.r4.utils.FHIRPathUtilityClasses.FunctionDetails;
021
022import java.util.List;
023import java.util.Optional;
024
025public class FhirPathR4 implements IFhirPath {
026
027        private final FHIRPathEngine myEngine;
028
029        public FhirPathR4(FhirContext theCtx) {
030                IValidationSupport validationSupport = theCtx.getValidationSupport();
031                myEngine = new FHIRPathEngine(new HapiWorkerContext(theCtx, validationSupport));
032                // These changes are to make the FP evaluation non-strict
033                myEngine.setDoNotEnforceAsCaseSensitive(true);
034                myEngine.setDoNotEnforceAsSingletonRule(true);
035        }
036
037        @SuppressWarnings("unchecked")
038        @Override
039        public <T extends IBase> List<T> evaluate(IBase theInput, String thePath, Class<T> theReturnType) {
040                ExpressionNode parsed;
041                try {
042                        parsed = myEngine.parse(thePath);
043                } catch (FHIRException e) {
044                        throw new FhirPathExecutionException(Msg.code(2409) + e);
045                }
046                return (List<T>) evaluate(theInput, parsed, theReturnType);
047        }
048
049        @SuppressWarnings("unchecked")
050        @Override
051        public <T extends IBase> List<T> evaluate(
052                        IBase theInput, IParsedExpression theParsedExpression, Class<T> theReturnType) {
053                ExpressionNode expressionNode = ((ParsedExpression) theParsedExpression).myParsedExpression;
054                return (List<T>) evaluate(theInput, expressionNode, theReturnType);
055        }
056
057        @Nonnull
058        private <T extends IBase> List<Base> evaluate(
059                        IBase theInput, ExpressionNode expressionNode, Class<T> theReturnType) {
060                List<Base> result;
061                try {
062                        result = myEngine.evaluate((Base) theInput, expressionNode);
063                } catch (FHIRException e) {
064                        throw new FhirPathExecutionException(Msg.code(255) + e.getMessage(), e);
065                }
066
067                for (IBase next : result) {
068                        if (!theReturnType.isAssignableFrom(next.getClass())) {
069                                throw new FhirPathExecutionException(Msg.code(256) + "FhirPath expression returned unexpected type "
070                                                + next.getClass().getSimpleName() + " - Expected " + theReturnType.getName());
071                        }
072                }
073                return result;
074        }
075
076        @Override
077        public <T extends IBase> Optional<T> evaluateFirst(IBase theInput, String thePath, Class<T> theReturnType) {
078                return evaluate(theInput, thePath, theReturnType).stream().findFirst();
079        }
080
081        @Override
082        public <T extends IBase> Optional<T> evaluateFirst(
083                        IBase theInput, IParsedExpression theParsedExpression, Class<T> theReturnType) {
084                return evaluate(theInput, theParsedExpression, theReturnType).stream().findFirst();
085        }
086
087        @Override
088        public IParsedExpression parse(String theExpression) {
089                return new ParsedExpression(myEngine.parse(theExpression));
090        }
091
092        @Override
093        public void setEvaluationContext(@Nonnull IFhirPathEvaluationContext theEvaluationContext) {
094                myEngine.setHostServices(new FHIRPathEngine.IEvaluationContext() {
095
096                        @Override
097                        public List<Base> resolveConstant(Object appContext, String name, boolean beforeContext)
098                                        throws PathEngineException {
099                                return null;
100                        }
101
102                        @Override
103                        public TypeDetails resolveConstantType(Object appContext, String name) throws PathEngineException {
104                                return null;
105                        }
106
107                        @Override
108                        public boolean log(String argument, List<Base> focus) {
109                                return false;
110                        }
111
112                        @Override
113                        public FunctionDetails resolveFunction(String functionName) {
114                                return null;
115                        }
116
117                        @Override
118                        public TypeDetails checkFunction(Object appContext, String functionName, List<TypeDetails> parameters)
119                                        throws PathEngineException {
120                                return null;
121                        }
122
123                        @Override
124                        public List<Base> executeFunction(
125                                        Object appContext, List<Base> focus, String functionName, List<List<Base>> parameters) {
126                                return null;
127                        }
128
129                        @Override
130                        public Base resolveReference(Object appContext, String theUrl, Base theRefContext) throws FHIRException {
131                                return (Base) theEvaluationContext.resolveReference(new IdType(theUrl), theRefContext);
132                        }
133
134                        @Override
135                        public boolean conformsToProfile(Object appContext, Base item, String url) throws FHIRException {
136                                return false;
137                        }
138
139                        @Override
140                        public ValueSet resolveValueSet(Object appContext, String url) {
141                                return null;
142                        }
143                });
144        }
145
146        private static class ParsedExpression implements IParsedExpression {
147
148                private final ExpressionNode myParsedExpression;
149
150                public ParsedExpression(ExpressionNode theParsedExpression) {
151                        myParsedExpression = theParsedExpression;
152                }
153        }
154}