From f8a19a1bae3554d08f295e94f8b112bce084f209 Mon Sep 17 00:00:00 2001
From: Grahame Grieve <grahameg@gmail.ccom>
Date: Sat, 18 Mar 2023 05:47:33 +1100
Subject: [PATCH] Refactor how mappings are handled when generating
 differentials: in R5, mapping names are unique

---
 .../conformance/profile/ProfileUtilities.java | 76 ++++++++++++++-----
 .../validation/special/R4R5MapTester.java     |  6 +-
 pom.xml                                       |  2 +-
 3 files changed, 61 insertions(+), 23 deletions(-)

diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/conformance/profile/ProfileUtilities.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/conformance/profile/ProfileUtilities.java
index 9b32e57e4..9b216e802 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/conformance/profile/ProfileUtilities.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/conformance/profile/ProfileUtilities.java
@@ -130,6 +130,13 @@ import org.hl7.fhir.utilities.xml.SchematronWriter.Section;
  */
 public class ProfileUtilities extends TranslatingUtilities {
 
+  public enum MappingMergeModeOption {
+    DUPLICATE, // if there's more than one mapping for the same URI, just keep them all
+    IGNORE, // if there's more than one, keep the first 
+    OVERWRITE, // if there's opre than, keep the last 
+    APPEND, // if there's more than one, append them with ';' 
+  }
+
   public enum AllowUnknownProfile {
     NONE, // exception if there's any unknown profiles (the default)
     NON_EXTNEIONS, // don't raise an exception except on Extension (because more is going on there
@@ -280,6 +287,7 @@ public class ProfileUtilities extends TranslatingUtilities {
   private Set<String> masterSourceFileNames;
   private Map<ElementDefinition, SourcedChildDefinitions> childMapCache = new HashMap<>();
   private AllowUnknownProfile allowUnknownProfile = AllowUnknownProfile.ALL_TYPES;
+  private MappingMergeModeOption mappingMergeMode = MappingMergeModeOption.APPEND;
 
   public ProfileUtilities(IWorkerContext context, List<ValidationMessage> messages, ProfileKnowledgeProvider pkp, FHIRPathEngine fpe) {
     super();
@@ -2263,25 +2271,11 @@ public class ProfileUtilities extends TranslatingUtilities {
       }
 
       if (derived.hasMapping()) {
-        // todo: mappings are not cumulative - one replaces another
-        if (!Base.compareDeep(derived.getMapping(), base.getMapping(), false)) {
-          for (ElementDefinitionMappingComponent s : derived.getMapping()) {
-            boolean found = false;
-            for (ElementDefinitionMappingComponent d : base.getMapping()) {
-              found = found || (d.getIdentity().equals(s.getIdentity()) && d.getMap().equals(s.getMap()));
-            }
-            if (!found) {
-              base.getMapping().add(s);
-            }
-          }
-        }
-        else if (trimDifferential) {
-          derived.getMapping().clear();
-        } else { 
-          for (ElementDefinitionMappingComponent t : derived.getMapping()) {
-            t.setUserData(UD_DERIVATION_EQUALS, true);
-          }
-        }
+        List<ElementDefinitionMappingComponent> list = new ArrayList<>();
+        list.addAll(base.getMapping());
+        base.getMapping().clear();
+        addMappings(base.getMapping(), list);
+        addMappings(base.getMapping(), derived.getMapping());
       }
       for (ElementDefinitionMappingComponent m : base.getMapping()) {
         if (m.hasMap()) {
@@ -2332,6 +2326,50 @@ public class ProfileUtilities extends TranslatingUtilities {
     }
   }
 
+  private void addMappings(List<ElementDefinitionMappingComponent> destination, List<ElementDefinitionMappingComponent> source) {
+    for (ElementDefinitionMappingComponent s : source) {
+      boolean found = false;
+      for (ElementDefinitionMappingComponent d : destination) {
+        if (compareMaps(s, d)) {
+          found = true;
+          d.setUserData(UD_DERIVATION_EQUALS, true);
+          break;
+        }
+      }
+      if (!found) {
+        destination.add(s);
+      }
+    }
+  }
+
+  private boolean compareMaps(ElementDefinitionMappingComponent s, ElementDefinitionMappingComponent d) {
+    if (d.getIdentity().equals(s.getIdentity()) && d.getMap().equals(s.getMap())) {
+      return true;
+    }
+    if (VersionUtilities.isR5Plus(context.getVersion())) {
+      if (d.getIdentity().equals(s.getIdentity())) {
+        switch (mappingMergeMode) {
+        case APPEND:
+          d.setMap(d.getMap()+";"+s.getMap());
+          return true;
+        case DUPLICATE:
+          return false;
+        case IGNORE:
+          d.setMap(s.getMap());
+          return true;
+        case OVERWRITE:
+          return true;
+        default:
+          return false;
+        }
+      } else {
+        return false;
+      }
+    } else {
+      return false;
+    }
+  }
+
   private void checkTypeDerivation(String purl, StructureDefinition srcSD, ElementDefinition base, ElementDefinition derived, TypeRefComponent ts) {
     boolean ok = false;
     CommaSeparatedStringBuilder b = new CommaSeparatedStringBuilder();
diff --git a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/special/R4R5MapTester.java b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/special/R4R5MapTester.java
index 1a1d9f2aa..e719d133f 100644
--- a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/special/R4R5MapTester.java
+++ b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/special/R4R5MapTester.java
@@ -135,12 +135,12 @@ public class R4R5MapTester implements IValidatorResourceFetcher {
       back++;
     }
 
-    public void elements(int elementCountBefore) {
-      elements++;
+    public void elements(int i) {
+      elements = elements+i;
     }
 
     public void lost(int i) {
-      lostElements++;
+      lostElements = lostElements + i;
     }
 
     public int elementsCount() {
diff --git a/pom.xml b/pom.xml
index 2035a46fa..25c91ee1e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -19,7 +19,7 @@
 
     <properties>
         <hapi_fhir_version>6.2.1</hapi_fhir_version>
-        <validator_test_case_version>1.2.20</validator_test_case_version>
+        <validator_test_case_version>1.2.21-SNAPSHOT</validator_test_case_version>
         <junit_jupiter_version>5.7.1</junit_jupiter_version>
         <junit_platform_launcher_version>1.8.2</junit_platform_launcher_version>
         <maven_surefire_version>3.0.0-M5</maven_surefire_version>