Merge pull request #34 from FirelyTeam/ncqa/add-default-codesystems

Add default codesystem in attributes

Author: mmsmits

src/Microsoft.Health.Fhir.SpecManager/Language/CSharpFirely2.cs

@@ -1787,7 +1787,11 @@ private void WriteEnum(
                         $"(systems: {vs.ReferencedCodeSystems.Count})");
                 }
 
-                _writer.WriteLineIndented($"[FhirEnumeration(\"{name}\", \"{vs.URL}\")]");
+
+
+                var defaultSystem = GetDefaultCodeSystem(vs.Concepts);
+
+                _writer.WriteLineIndented($"[FhirEnumeration(\"{name}\", \"{vs.URL}\", \"{defaultSystem}\")]");
 
                 _writer.WriteLineIndented($"public enum {nameSanitized}");
 
@@ -1812,7 +1816,10 @@ private void WriteEnum(
 
                     string display = FhirUtils.SanitizeForValue(concept.Display);
 
-                    _writer.WriteLineIndented($"[EnumLiteral(\"{codeValue}\", \"{concept.System}\"), Description(\"{display}\")]");
+                    if (concept.System != defaultSystem)
+                        _writer.WriteLineIndented($"[EnumLiteral(\"{codeValue}\", \"{concept.System}\"), Description(\"{display}\")]");
+                    else
+                        _writer.WriteLineIndented($"[EnumLiteral(\"{codeValue}\"), Description(\"{display}\")]");
 
                     if (usedLiterals.Contains(codeName))
                     {
@@ -1846,6 +1853,14 @@ private void WriteEnum(
                 });
         }
 
+        private static string GetDefaultCodeSystem(List<FhirConcept> concepts)
+        {
+            return concepts.Select(c => c.System)
+                            .GroupBy(c => c)
+                            .OrderByDescending(c => c.Count())
+                            .First().Key;
+        }
+
         /// <summary>Convert enum value - see Template-Model.tt#2061.</summary>
         /// <param name="name">The name.</param>
         /// <returns>The enum converted value.</returns>