Phase 7: Dual-mode glucose chart, HealthKit data pipeline, and quality fixes

Glucose chart now operates in two modes: standard Ambulatory Glucose Profile
(24-hour overlay with percentile bands) for 14-day lookback, and Glucose Profile
(multi-day time series) for all other periods. Both modes include an info button
explaining the visualization. HealthKit glucose data supplements Loop store for
longer analysis periods. Chart data clears on period change to prevent stale labels.

Additional fixes across 22 files: improved HealthKit data pipeline reliability,
enhanced test data provider, refined food response analysis, and minor bug fixes
in background monitor, coordinator, caffeine tracker, and goals/trends views.

Author: taylorpatterson-T1D

Loop/Localizable.xcstrings

@@ -629,18 +629,6 @@
         }
       }
     },
-    "%@ [%lld chars]" : {
-      "comment" : "A view that displays a meal with its food type, date, and glucose response. The \"Pre-Meal Advice\" tab in the Loop Insights app uses this view to show individual meal cards.",
-      "isCommentAutoGenerated" : true,
-      "localizations" : {
-        "en" : {
-          "stringUnit" : {
-            "state" : "new",
-            "value" : "%1$@ [%2$lld chars]"
-          }
-        }
-      }
-    },
     "%@ %@" : {
       "comment" : "The format for an active custom preset. (1: preset symbol)(2: preset name)",
       "localizations" : {
@@ -5969,6 +5957,9 @@
     "AGP Chart" : {
       "comment" : "LoopInsights AGP toggle"
     },
+    "AGP is a standardized reporting format developed by the International Diabetes Center. It overlays 14 days of CGM data into a single 24-hour view, displaying the median (P50), interquartile range (P25–P75), and 10th/90th percentile bands.\n\nThis format lets you and your clinician spot recurring daily patterns — like dawn phenomenon or post-meal spikes — at a glance, using the same visual language across institutions." : {
+      "comment" : "LoopInsights AGP info alert message"
+    },
     "AI Advice" : {
       "comment" : "LoopInsights AI advice header"
     },
@@ -6607,7 +6598,7 @@
       "comment" : "LoopInsights quick ask: meal bolus"
     },
     "Ambulatory Glucose Profile" : {
-      "comment" : "LoopInsights AGP chart title"
+      "comment" : "LoopInsights AGP chart title\nLoopInsights AGP info alert title"
     },
     "Amount (mg)" : {
       "comment" : "LoopInsights caffeine amount\nLoopInsights caffeine amount placeholder"
@@ -21002,6 +20993,12 @@
         }
       }
     },
+    "Glucose Profile" : {
+      "comment" : "LoopInsights glucose profile chart title\nLoopInsights glucose profile info alert title"
+    },
+    "Glucose Profile displays your CGM data across the selected time period using percentile bands.\n\nThe median line (P50) shows your typical glucose at each point in time. The shaded bands show the interquartile range (P25–P75) and the 10th/90th percentile spread, giving you a sense of variability.\n\nFor a standardized Ambulatory Glucose Profile (AGP) — which overlays all days into a single 24-hour view — select the 14-day lookback period." : {
+      "comment" : "LoopInsights glucose profile info alert message"
+    },
     "Glucose Target Range Schedule" : {
       "comment" : "Details for configuration error when glucose target range schedule is missing",
       "localizations" : {
@@ -28685,7 +28682,7 @@
     "Not enough\ndata available" : {
       "comment" : "LoopInsights GMI insufficient data"
     },
-    "Not enough data for AGP chart" : {
+    "Not enough data for glucose profile" : {
       "comment" : "LoopInsights AGP no data"
     },
     "Notification Delivery" : {

Loop/Managers/LoopInsights/LoopInsights_BackgroundMonitor.swift

@@ -9,6 +9,7 @@
 import Foundation
 import UserNotifications
 import Combine
+import os.log
 
 /// Monitors Loop's completion cycle and periodically runs AI analysis
 /// to proactively detect therapy setting adjustment opportunities.
@@ -54,7 +55,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
     func start() {
         guard loopCompletedObserver == nil else { return }
         guard LoopInsights_FeatureFlags.backgroundMonitorEnabled else {
-            print("[LoopInsights Monitor] Background monitoring is disabled")
+            LoopInsights_FeatureFlags.log.info("Background monitoring is disabled")
             return
         }
 
@@ -66,7 +67,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
             self?.handleLoopCompleted()
         }
 
-        print("[LoopInsights Monitor] Started — frequency: \(LoopInsights_FeatureFlags.monitorFrequency.displayName)")
+        LoopInsights_FeatureFlags.log.info("Monitor started — frequency: \(LoopInsights_FeatureFlags.monitorFrequency.displayName)")
     }
 
     /// Stop observing and cancel any pending work.
@@ -75,7 +76,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
             NotificationCenter.default.removeObserver(observer)
             loopCompletedObserver = nil
         }
-        print("[LoopInsights Monitor] Stopped")
+        LoopInsights_FeatureFlags.log.info("Monitor stopped")
     }
 
     /// Restart the monitor (e.g. after settings change).
@@ -136,7 +137,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
     // MARK: - Background Analysis
 
     private func runBackgroundAnalysis() async {
-        print("[LoopInsights Monitor] Running background analysis...")
+        LoopInsights_FeatureFlags.log.debug("Running background analysis...")
 
         do {
             let period = LoopInsights_FeatureFlags.analysisPeriod
@@ -163,7 +164,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
             UserDefaults.standard.set(Date().timeIntervalSince1970, forKey: Self.lastAnalysisKey)
 
             guard !newSuggestions.isEmpty else {
-                print("[LoopInsights Monitor] No new suggestions found")
+                LoopInsights_FeatureFlags.log.debug("No new suggestions found")
                 return
             }
 
@@ -177,7 +178,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
             }
 
             guard !genuinelyNew.isEmpty else {
-                print("[LoopInsights Monitor] Suggestions match existing pending — no notification needed")
+                LoopInsights_FeatureFlags.log.debug("Suggestions match existing pending — no notification needed")
                 return
             }
 
@@ -188,7 +189,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
             await deliverNotification(for: genuinelyNew)
 
         } catch {
-            print("[LoopInsights Monitor] Analysis failed: \(error.localizedDescription)")
+            LoopInsights_FeatureFlags.log.error("Background analysis failed: \(error.localizedDescription)")
         }
     }
 
@@ -199,7 +200,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
 
         // Check quiet hours — still store suggestions but suppress notifications
         if isInQuietHours() {
-            print("[LoopInsights Monitor] Quiet hours active — suppressing notification")
+            LoopInsights_FeatureFlags.log.info("Quiet hours active — suppressing notification")
             return
         }
 
@@ -212,7 +213,7 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
             await deliverPushNotification(suggestions: suggestions)
         case .silent:
             // No notification — suggestions are available in the store
-            print("[LoopInsights Monitor] Silent mode — \(suggestions.count) suggestion(s) stored")
+            LoopInsights_FeatureFlags.log.debug("Silent mode — \(suggestions.count) suggestion(s) stored")
         }
     }
 
@@ -251,9 +252,9 @@ final class LoopInsights_BackgroundMonitor: ObservableObject {
 
         do {
             try await UNUserNotificationCenter.current().add(request)
-            print("[LoopInsights Monitor] Push notification sent for \(suggestions.count) suggestion(s)")
+            LoopInsights_FeatureFlags.log.info("Push notification sent for \(suggestions.count) suggestion(s)")
         } catch {
-            print("[LoopInsights Monitor] Failed to send notification: \(error.localizedDescription)")
+            LoopInsights_FeatureFlags.log.error("Failed to send notification: \(error.localizedDescription)")
         }
     }
 

Loop/Managers/LoopInsights/LoopInsights_Coordinator.swift

@@ -95,11 +95,11 @@ final class LoopInsights_Coordinator: ObservableObject {
 
         let provider = LoopInsights_TestDataProvider()
         guard provider.hasTestData else {
-            print("[LoopInsights] Test data mode enabled but no fixtures found")
+            LoopInsights_FeatureFlags.log.info("Test data mode enabled but no fixtures found")
             return nil
         }
 
-        print("[LoopInsights] Using test data: \(provider.dataSummary)")
+        LoopInsights_FeatureFlags.log.info("Using test data: \(provider.dataSummary)")
         return LoopInsights_Coordinator(testDataProvider: provider)
     }
 
@@ -108,7 +108,7 @@ final class LoopInsights_Coordinator: ObservableObject {
     /// Start background monitoring if enabled and using real stores (not test data).
     func startBackgroundMonitoring() {
         guard dataProviderBridge != nil else {
-            print("[LoopInsights] Skipping background monitor — test data mode")
+            LoopInsights_FeatureFlags.log.debug("Skipping background monitor — test data mode")
             return
         }
         backgroundMonitor.start()
@@ -138,7 +138,8 @@ final class LoopInsights_Coordinator: ObservableObject {
         // P3: Use pre-fetched glucose, fall back to bridge only if not provided
         var resolvedGlucose: [StoredGlucoseSample]? = glucoseSamples
         if resolvedGlucose == nil, let bridge = dataProviderBridge {
-            resolvedGlucose = try? await bridge.getGlucoseSamples(start: start, end: end)
+            do { resolvedGlucose = try await bridge.getGlucoseSamples(start: start, end: end) }
+            catch { LoopInsights_FeatureFlags.log.error("Supplemental context: glucose fetch failed: \(error)") }
         }
 
         // Circadian + Dawn Phenomenon + Negative Basal + Stress
@@ -171,7 +172,8 @@ final class LoopInsights_Coordinator: ObservableObject {
             // P3: Use pre-fetched carbs, fall back to bridge only if not provided
             var resolvedCarbs: [StoredCarbEntry]? = carbEntries
             if resolvedCarbs == nil, let bridge = dataProviderBridge {
-                resolvedCarbs = try? await bridge.getCarbEntries(start: start, end: end)
+                do { resolvedCarbs = try await bridge.getCarbEntries(start: start, end: end) }
+                catch { LoopInsights_FeatureFlags.log.error("Supplemental context: carbs fetch failed: \(error)") }
             }
             if let carbs = resolvedCarbs, let glucSamples = resolvedGlucose {
                 let patterns = LoopInsights_FoodResponseAnalyzer.analyzeFoodResponses(
@@ -224,7 +226,7 @@ final class LoopInsights_Coordinator: ObservableObject {
     @discardableResult
     func applyTherapyChanges(suggestion: LoopInsightsSuggestion) -> Bool {
         guard let writer = settingsWriter else {
-            print("[LoopInsights] Cannot apply: no settings writer available (test data mode?)")
+            LoopInsights_FeatureFlags.log.error("Cannot apply: no settings writer available (test data mode?)")
             return false
         }
 
@@ -256,7 +258,7 @@ final class LoopInsights_Coordinator: ObservableObject {
             }
         }
 
-        print("[LoopInsights] Applied \(suggestion.settingType.displayName) changes: \(blocks.count) time block(s)")
+        LoopInsights_FeatureFlags.log.info("Applied \(suggestion.settingType.displayName) changes: \(blocks.count) time block(s)")
         return true
     }
 
@@ -266,7 +268,7 @@ final class LoopInsights_Coordinator: ObservableObject {
     @discardableResult
     func revertToSnapshot(_ snapshot: LoopInsightsTherapySnapshot) -> Bool {
         guard let writer = settingsWriter else {
-            print("[LoopInsights] Cannot revert: no settings writer available")
+            LoopInsights_FeatureFlags.log.error("Cannot revert: no settings writer available")
             return false
         }
 
@@ -305,7 +307,7 @@ final class LoopInsights_Coordinator: ObservableObject {
             }
         }
 
-        print("[LoopInsights] Reverted settings to previous snapshot")
+        LoopInsights_FeatureFlags.log.info("Reverted settings to previous snapshot")
         return true
     }
 

Loop/Models/LoopInsights/LoopInsights_Models.swift

@@ -869,3 +869,22 @@ final class LoopInsightsChatSession: ObservableObject {
         messages.removeAll()
     }
 }
+
+// MARK: - Binary Search Utility
+
+extension Array {
+    /// Binary search for the first index in a sorted array where `keyPath` is at or after `date`.
+    /// The array must be sorted by the key in ascending order.
+    func loopInsights_firstIndex(afterOrAt date: Date, by dateExtractor: (Element) -> Date) -> Int {
+        var lo = 0, hi = count
+        while lo < hi {
+            let mid = (lo + hi) / 2
+            if dateExtractor(self[mid]) < date {
+                lo = mid + 1
+            } else {
+                hi = mid
+            }
+        }
+        return lo
+    }
+}

Loop/Models/LoopInsights/LoopInsights_Phase5Models.swift

@@ -222,9 +222,9 @@ struct LoopInsightsNightscoutTreatment: Codable {
 
 // MARK: - AGP Data Point
 
-/// A single time point in an Ambulatory Glucose Profile
+/// A single time-window in a glucose profile chart spanning the analysis period.
 struct LoopInsightsAGPDataPoint {
-    let minuteOfDay: Int     // 0-1439
+    let date: Date           // Bucket midpoint
     let p10: Double          // 10th percentile mg/dL
     let p25: Double          // 25th percentile mg/dL
     let p50: Double          // 50th (median) mg/dL

Loop/Resources/LoopInsights/LoopInsights_FeatureFlags.swift

@@ -7,11 +7,15 @@
 //
 
 import Foundation
+import os.log
 
 /// Runtime feature flags for LoopInsights. All flags are UserDefaults-backed
 /// so they can be toggled without recompilation.
 struct LoopInsights_FeatureFlags {
 
+    /// Shared logger for all LoopInsights subsystems
+    static let log = Logger(subsystem: "com.loopkit.Loop.LoopInsights", category: "LoopInsights")
+
     private enum Keys {
         static let isEnabled = "LoopInsights_isEnabled"
         static let developerModeEnabled = "LoopInsights_developerModeEnabled"

Loop/Services/LoopInsights/LoopInsights_AdvancedAnalyzers.swift

@@ -156,7 +156,7 @@ final class LoopInsights_AdvancedAnalyzers {
                 // P5: Binary search for overcorrection check instead of linear scan
                 let checkStart = dose.endDate
                 let checkEnd = dose.endDate.addingTimeInterval(2 * 3600)
-                let startIdx = Self.binarySearchFirstIndex(in: sortedGlucose, afterOrAt: checkStart)
+                let startIdx = sortedGlucose.loopInsights_firstIndex(afterOrAt: checkStart) { $0.startDate }
                 var reboundHigh = false
                 for i in startIdx..<sortedGlucose.count {
                     let sample = sortedGlucose[i]
@@ -292,20 +292,4 @@ final class LoopInsights_AdvancedAnalyzers {
         return result
     }
 
-    /// P5: Binary search to find the first glucose sample at or after `date` in a sorted array.
-    static func binarySearchFirstIndex(
-        in samples: [StoredGlucoseSample],
-        afterOrAt date: Date
-    ) -> Int {
-        var lo = 0, hi = samples.count
-        while lo < hi {
-            let mid = (lo + hi) / 2
-            if samples[mid].startDate < date {
-                lo = mid + 1
-            } else {
-                hi = mid
-            }
-        }
-        return lo
-    }
 }

Loop/Services/LoopInsights/LoopInsights_CaffeineTracker.swift

@@ -50,7 +50,7 @@ final class LoopInsights_CaffeineTracker: ObservableObject {
                 self.rebuildMergedEntries()
             }
         } catch {
-            print("[LoopInsights] Failed to fetch HealthKit caffeine: \(error)")
+            LoopInsights_FeatureFlags.log.error("Failed to fetch HealthKit caffeine: \(error)")
         }
     }