Show backfilled readings in Recent Readings

LibreLoop/LibreLoopCGMManager/LibreLoopCGMManager.swift

@@ -294,6 +294,7 @@ public final class LibreLoopCGMManager: CGMManager {
     }
 
     func recordSample(_ sample: LibreLoopGlucoseSample) {
+        recentSamples.removeAll { $0.lifeCount == sample.lifeCount && $0.source != .realtime }
         recentSamples.insert(sample, at: 0)
         if recentSamples.count > Self.recentSamplesCap {
             recentSamples.removeLast(recentSamples.count - Self.recentSamplesCap)
@@ -306,6 +307,18 @@ public final class LibreLoopCGMManager: CGMManager {
         setState(updated)
     }
 
+    /// Adds backfilled readings to Recent Readings, in lifeCount order, without
+    /// touching the Last Reading card.
+    func recordBackfillSamples(_ samples: [LibreLoopGlucoseSample]) {
+        let known = Set(recentSamples.map(\.lifeCount))
+        let added = samples.filter { !known.contains($0.lifeCount) }
+        guard !added.isEmpty else { return }
+        recentSamples = Array((recentSamples + added).sorted { $0.lifeCount > $1.lifeCount }.prefix(Self.recentSamplesCap))
+        var updated = state
+        updated.recentSamples = Array(recentSamples.prefix(LibreLoopCGMManagerState.recentSamplesPersistenceCap))
+        setState(updated)
+    }
+
     /// Update the most recently recorded sample with its forwarding
     /// outcome (sent vs throttled vs non-actionable). Matched by
     /// lifeCount, which is unique within a sensor session. No-op if the

LibreLoop/Pairing/LibreLoopCGMManager+Pairing.swift

@@ -674,8 +674,9 @@ extension LibreLoopCGMManager {
         // (historical and clinical can overlap, and they may not even agree
         // on values for the same lifeCount since they're different sensor
         // pipelines).
-        let realtimeLifeCounts = Set(recentSamples.map { $0.lifeCount })
+        let realtimeLifeCounts = Set(recentSamples.filter { $0.source == .realtime }.map { $0.lifeCount })
         var newSamples: [NewGlucoseSample] = []
+        var displaySamples: [LibreLoopGlucoseSample] = []
         var droppedRealtimeDup = 0
         var droppedBackfillDup = 0
         for sample in page.samples {
@@ -706,8 +707,20 @@ extension LibreLoopCGMManager {
                 device: device,
                 isBackfill: true
             ))
+            displaySamples.append(LibreLoopGlucoseSample(
+                date: date,
+                valueMgDL: Double(mgdl),
+                trend: .notDetermined,
+                rateOfChangeMgDLPerMinute: nil,
+                lifeCount: sample.lifeCount,
+                sensorTemperatureRaw: 0,
+                isActionable: true,
+                source: .historicalBackfill,
+                wasForwarded: true
+            ))
             backfillForwardedLifeCounts.insert(sample.lifeCount)
         }
+        recordBackfillSamples(displaySamples)
         if !newSamples.isEmpty {
             delegateQueue?.async { [weak self] in
                 guard let self else { return }
@@ -750,7 +763,7 @@ extension LibreLoopCGMManager {
             return
         }
         let serial = state.sensorSerial ?? "unknown"
-        let realtimeLifeCounts = Set(recentSamples.map { $0.lifeCount })
+        let realtimeLifeCounts = Set(recentSamples.filter { $0.source == .realtime }.map { $0.lifeCount })
 
         // Forward only the per-minute `currentGlucoseMgDL` at
         // `record.lifeCount`. Per upstream RoundWhiteDiscKit guidance:
@@ -811,6 +824,17 @@ extension LibreLoopCGMManager {
             isBackfill: true
         )
         backfillForwardedLifeCounts.insert(lifeCount)
+        recordBackfillSamples([LibreLoopGlucoseSample(
+            date: date,
+            valueMgDL: Double(mgdl),
+            trend: .notDetermined,
+            rateOfChangeMgDLPerMinute: nil,
+            lifeCount: lifeCount,
+            sensorTemperatureRaw: 0,
+            isActionable: true,
+            source: .clinicalBackfill,
+            wasForwarded: true
+        )])
         llog("forwarded clinical \(kind) sample to Loop: \(mgdl) mg/dL lifeCount=\(lifeCount) sampleDate=\(date.timeIntervalSince1970)")
         delegateQueue?.async { [weak self] in
             guard let self else { return }

LibreLoop/Sensor/LibreLoopGlucoseSample.swift

@@ -60,9 +60,7 @@ public struct LibreLoopGlucoseSample: Equatable, Sendable {
     /// reading actionable (e.g. "Warming up: 18 min remaining",
     /// "Sensor condition: invalid"). nil when the reading IS actionable.
     public let qualityIssue: String?
-    /// How this sample reached LibreLoop. Currently `recentSamples` only
-    /// contains `.realtime` entries; the field exists so backfill samples
-    /// can be surfaced in the same list later without a schema bump.
+    /// How this sample reached LibreLoop.
     public let source: Source
     /// True iff this sample was actually handed off to Loop's CGMManager
     /// delegate. Updated in place after the throttle/actionability gate

LibreLoopTests/LibreLoopCGMManagerStateTests.swift

@@ -221,3 +221,42 @@ final class LibreLoopSensorStateEventTests: XCTestCase {
         XCTAssertEqual(restored?.sensorEndRecorded, true)
     }
 }
+
+final class LibreLoopRecentReadingsTests: XCTestCase {
+    private let activatedAt = Date(timeIntervalSince1970: 1_700_000_000)
+
+    private func sample(_ lifeCount: UInt16, _ mgdl: Double, source: LibreLoopGlucoseSample.Source = .realtime) -> LibreLoopGlucoseSample {
+        LibreLoopGlucoseSample(
+            date: activatedAt.addingTimeInterval(TimeInterval(lifeCount) * 60),
+            valueMgDL: mgdl,
+            trend: source == .realtime ? .stable : .notDetermined,
+            rateOfChangeMgDLPerMinute: nil,
+            lifeCount: lifeCount,
+            sensorTemperatureRaw: 0,
+            isActionable: true,
+            source: source
+        )
+    }
+
+    func testBackfillFillsTheGapInLifeCountOrder() {
+        let manager = LibreLoopCGMManager()
+        manager.recordSample(sample(100, 90))
+        manager.recordSample(sample(130, 92))
+
+        manager.recordBackfillSamples([sample(110, 93, source: .historicalBackfill), sample(100, 91, source: .historicalBackfill)])
+        manager.recordBackfillSamples([sample(120, 94, source: .clinicalBackfill)])
+
+        XCTAssertEqual(manager.recentSamples.map(\.lifeCount), [130, 120, 110, 100])
+        XCTAssertEqual(manager.recentSamples.map(\.source), [.realtime, .clinicalBackfill, .historicalBackfill, .realtime])
+        XCTAssertEqual(manager.latestSample?.lifeCount, 130)
+    }
+
+    func testRealtimeReplacesBackfillForTheSameMinute() {
+        let manager = LibreLoopCGMManager()
+        manager.recordBackfillSamples([sample(140, 95, source: .clinicalBackfill)])
+        manager.recordSample(sample(140, 96))
+
+        XCTAssertEqual(manager.recentSamples.map(\.lifeCount), [140])
+        XCTAssertEqual(manager.recentSamples.first?.source, .realtime)
+    }
+}

LibreLoopUI/Localizable.xcstrings

@@ -67,6 +67,10 @@
       "comment" : "BLE PIN row label",
       "extractionState" : "manual"
     },
+    "Backfilled" : {
+      "comment" : "Recent readings: backfilled reading marker",
+      "extractionState" : "manual"
+    },
     "Bluetooth" : {
       "comment" : "Bluetooth address row label\n   Bluetooth connection row label",
       "extractionState" : "manual"

LibreLoopUI/Views/LibreLoopSampleDetailView.swift

@@ -62,10 +62,12 @@ struct LibreLoopSampleDetailView: View {
                     .monospacedDigit()
             }
 
-            Section(LocalizedString("Sensor diagnostics", comment: "Sample detail section: diagnostics")) {
-                LabeledContent(LocalizedString("Temperature (raw)", comment: "Sample detail: raw sensor temperature"), value: "0x\(String(sample.sensorTemperatureRaw, radix: 16, uppercase: true)) (\(sample.sensorTemperatureRaw))")
-                    .monospaced()
-                    .font(.footnote)
+            if sample.source == .realtime {
+                Section(LocalizedString("Sensor diagnostics", comment: "Sample detail section: diagnostics")) {
+                    LabeledContent(LocalizedString("Temperature (raw)", comment: "Sample detail: raw sensor temperature"), value: "0x\(String(sample.sensorTemperatureRaw, radix: 16, uppercase: true)) (\(sample.sensorTemperatureRaw))")
+                        .monospaced()
+                        .font(.footnote)
+                }
             }
         }
         .navigationTitle(LocalizedString("Sample detail", comment: "Sample detail screen title"))

LibreLoopUI/Views/LibreLoopSettingsView.swift

@@ -606,8 +606,14 @@ struct LibreLoopReadingRow: View {
                     .imageScale(.small)
             }
             Spacer()
-            Image(systemName: trendSymbol)
-                .foregroundStyle(.secondary)
+            if sample.source == .realtime {
+                Image(systemName: trendSymbol)
+                    .foregroundStyle(.secondary)
+            } else {
+                Image(systemName: "clock.arrow.circlepath")
+                    .foregroundStyle(.secondary)
+                    .accessibilityLabel(LocalizedString("Backfilled", comment: "Recent readings: backfilled reading marker"))
+            }
         }
         .font(.subheadline)
         .opacity(sample.isActionable ? 1.0 : 0.7)