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.fhirpath.ExpressionNode;
014import org.hl7.fhir.r4.fhirpath.FHIRPathEngine;
015import org.hl7.fhir.r4.fhirpath.FHIRPathUtilityClasses.FunctionDetails;
016import org.hl7.fhir.r4.fhirpath.IHostApplicationServices;
017import org.hl7.fhir.r4.fhirpath.TypeDetails;
018import org.hl7.fhir.r4.hapi.ctx.HapiWorkerContext;
019import org.hl7.fhir.r4.model.Base;
020import org.hl7.fhir.r4.model.IdType;
021import org.hl7.fhir.r4.model.ValueSet;
022import org.hl7.fhir.utilities.fhirpath.FHIRPathConstantEvaluationMode;
023
024import java.util.List;
025import java.util.Optional;
026
027public class FhirPathR4 implements IFhirPath {
028
029        private final FHIRPathEngine myEngine;
030
031        public FhirPathR4(FhirContext theCtx) {
032                IValidationSupport validationSupport = theCtx.getValidationSupport();
033                myEngine = new FHIRPathEngine(new HapiWorkerContext(theCtx, validationSupport));
034                // These changes are to make the FP evaluation non-strict
035                myEngine.setDoNotEnforceAsCaseSensitive(true);
036                myEngine.setDoNotEnforceAsSingletonRule(true);
037        }
038
039        @SuppressWarnings("unchecked")
040        @Override
041        public <T extends IBase> List<T> evaluate(IBase theInput, String thePath, Class<T> theReturnType) {
042                ExpressionNode parsed;
043                try {
044                        parsed = myEngine.parse(thePath);
045                } catch (FHIRException e) {
046                        throw new FhirPathExecutionException(Msg.code(2409) + e, e);
047                }
048                return (List<T>) evaluate(theInput, parsed, theReturnType);
049        }
050
051        @SuppressWarnings("unchecked")
052        @Override
053        public <T extends IBase> List<T> evaluate(
054                        IBase theInput, IParsedExpression theParsedExpression, Class<T> theReturnType) {
055                ExpressionNode expressionNode = ((ParsedExpression) theParsedExpression).myParsedExpression;
056                return (List<T>) evaluate(theInput, expressionNode, theReturnType);
057        }
058
059        @Nonnull
060        private <T extends IBase> List<Base> evaluate(
061                        IBase theInput, ExpressionNode expressionNode, Class<T> theReturnType) {
062                List<Base> result;
063                try {
064                        result = myEngine.evaluate((Base) theInput, expressionNode);
065                } catch (FHIRException e) {
066                        throw new FhirPathExecutionException(Msg.code(255) + e.getMessage(), e);
067                }
068
069                for (IBase next : result) {
070                        if (!theReturnType.isAssignableFrom(next.getClass())) {
071                                throw new FhirPathExecutionException(Msg.code(256) + "FhirPath expression returned unexpected type "
072                                                + next.getClass().getSimpleName() + " - Expected " + theReturnType.getName());
073                        }
074                }
075                return result;
076        }
077
078        @Override
079        public <T extends IBase> Optional<T> evaluateFirst(IBase theInput, String thePath, Class<T> theReturnType) {
080                return evaluate(theInput, thePath, theReturnType).stream().findFirst();
081        }
082
083        @Override
084        public <T extends IBase> Optional<T> evaluateFirst(
085                        IBase theInput, IParsedExpression theParsedExpression, Class<T> theReturnType) {
086                return evaluate(theInput, theParsedExpression, theReturnType).stream().findFirst();
087        }
088
089        @Override
090        public IParsedExpression parse(String theExpression) {
091                return new ParsedExpression(myEngine.parse(theExpression));
092        }
093
094        @Override
095        public void setEvaluationContext(@Nonnull IFhirPathEvaluationContext theEvaluationContext) {
096                myEngine.setHostServices(new IHostApplicationServices() {
097
098                        @Override
099                        public List<Base> resolveConstant(
100                                        FHIRPathEngine engine, Object appContext, String name, FHIRPathConstantEvaluationMode mode)
101                                        throws PathEngineException {
102                                return null;
103                        }
104
105                        @Override
106                        public TypeDetails resolveConstantType(
107                                        FHIRPathEngine engine, Object appContext, String name, FHIRPathConstantEvaluationMode mode)
108                                        throws PathEngineException {
109                                return null;
110                        }
111
112                        @Override
113                        public boolean log(String argument, List<Base> focus) {
114                                return false;
115                        }
116
117                        @Override
118                        public FunctionDetails resolveFunction(FHIRPathEngine engine, String functionName) {
119                                return null;
120                        }
121
122                        @Override
123                        public TypeDetails checkFunction(
124                                        FHIRPathEngine engine,
125                                        Object appContext,
126                                        String functionName,
127                                        TypeDetails focus,
128                                        List<TypeDetails> parameters)
129                                        throws PathEngineException {
130                                return null;
131                        }
132
133                        @Override
134                        public List<Base> executeFunction(
135                                        FHIRPathEngine engine,
136                                        Object appContext,
137                                        List<Base> focus,
138                                        String functionName,
139                                        List<List<Base>> parameters) {
140                                return null;
141                        }
142
143                        @Override
144                        public Base resolveReference(FHIRPathEngine engine, Object appContext, String url, Base refContext)
145                                        throws FHIRException {
146                                return (Base) theEvaluationContext.resolveReference(new IdType(url), refContext);
147                        }
148
149                        @Override
150                        public boolean conformsToProfile(FHIRPathEngine engine, Object appContext, Base item, String url)
151                                        throws FHIRException {
152                                return false;
153                        }
154
155                        @Override
156                        public ValueSet resolveValueSet(FHIRPathEngine engine, Object appContext, String url) {
157                                return null;
158                        }
159
160                        @Override
161                        public boolean paramIsType(String name, int index) {
162                                return false;
163                        }
164                });
165        }
166
167        private static class ParsedExpression implements IParsedExpression {
168
169                private final ExpressionNode myParsedExpression;
170
171                public ParsedExpression(ExpressionNode theParsedExpression) {
172                        myParsedExpression = theParsedExpression;
173                }
174        }
175}