feature: FHIR R4 Inbound Facade

2026-06-21 13:53:38 +08:00
parent 9f96f54007
commit a43db52813
42 changed files with 2873 additions and 3 deletions
@@ -0,0 +1,89 @@
+using Hl7.Fhir.Model;
+using Task = System.Threading.Tasks.Task;
+
+public record MappedObservation(IngestObservationRequest Request, Guid EncounterId);
+
+public class ObservationFhirMapper
+{
+    private readonly FhirReferenceResolver _refs;
+
+    public ObservationFhirMapper(FhirReferenceResolver refs) => _refs = refs;
+
+    public async Task<IReadOnlyList<MappedObservation>> ToIngestRequestsAsync(Hl7.Fhir.Model.Observation fhir)
+    {
+        if (fhir.Encounter is null)
+            throw new FhirMappingException("Observation encounter reference is required.", "required");
+
+        var encounterId = await _refs.ResolveEncounterReferenceAsync(fhir.Encounter);
+        var source = MapSource(fhir);
+        var recordedAt = fhir.Effective.ToUtcDateTimeOffset() ?? DateTimeOffset.UtcNow;
+        var idempotencyKey = fhir.Identifier?.FirstOrDefault()?.Value ?? fhir.Id;
+
+        var results = new List<MappedObservation>();
+
+        if (fhir.Component?.Count > 0)
+        {
+            foreach (var component in fhir.Component)
+                results.AddRange(MapSingleCoding(
+                    component.Code, component.Value, encounterId, source, recordedAt,
+                    idempotencyKey is null ? null : $"{idempotencyKey}:{component.Code?.Coding?.FirstOrDefault()?.Code}"));
+        }
+        else
+        {
+            results.AddRange(MapSingleCoding(
+                fhir.Code, fhir.Value, encounterId, source, recordedAt, idempotencyKey));
+        }
+
+        if (results.Count == 0)
+            throw new FhirMappingException("Observation contains no mappable values.", "invalid");
+
+        return results;
+    }
+
+    private static ObservationSource MapSource(Hl7.Fhir.Model.Observation fhir)
+    {
+        var category = fhir.Category?.FirstOrDefault()?.Coding?.FirstOrDefault()?.Code;
+        return category switch
+        {
+            "vital-signs" => ObservationSource.Device,
+            "laboratory"  => ObservationSource.Lab,
+            _             => ObservationSource.Manual
+        };
+    }
+
+    private static List<MappedObservation> MapSingleCoding(
+        CodeableConcept? code,
+        DataType? value,
+        Guid encounterId,
+        ObservationSource source,
+        DateTimeOffset recordedAt,
+        string? idempotencyKey)
+    {
+        var coding = code?.Coding?.FirstOrDefault(c =>
+            !string.IsNullOrWhiteSpace(c.System) && !string.IsNullOrWhiteSpace(c.Code));
+
+        if (coding is null)
+            throw new FhirMappingException("Observation code coding is required.", "required");
+
+        if (!LoincCodeMapper.TryMap(coding.System!, coding.Code!, out var mapping))
+            throw new FhirMappingException(
+                $"Unsupported observation code {coding.System}|{coding.Code}.",
+                "not-supported");
+
+        if (value is not Quantity qty)
+            throw new FhirMappingException("Observation valueQuantity is required.", "required");
+
+        var (normalizedValue, _) = FhirUnitConverter.Normalize(
+            mapping.InternalCode, qty.Value ?? 0m, qty.Unit, mapping.AllowFahrenheit);
+
+        var request = new IngestObservationRequest(
+            ObservationCode: mapping.InternalCode,
+            Value: normalizedValue,
+            Unit: mapping.ExpectedUnit,
+            Source: source,
+            RecordedAt: recordedAt,
+            IdempotencyKey: idempotencyKey);
+
+        return [new MappedObservation(request, encounterId)];
+    }
+}