Compare outcomes since the last setup change with the period before it

Loop.xcodeproj/project.pbxproj

@@ -535,6 +535,10 @@
 		C16F51192B891DB600EFD7A1 /* StoredDataAlgorithmInput.swift in Sources */ = {isa = PBXBuildFile; fileRef = C16F51182B891DB600EFD7A1 /* StoredDataAlgorithmInput.swift */; };
 		52ECDA0F09B4C8F23A4B450E /* InsulinDeliveryHistory.swift in Sources */ = {isa = PBXBuildFile; fileRef = C4C16D18C8806FF48331134C /* InsulinDeliveryHistory.swift */; };
 		8879F70ABCDF1E10619547A4 /* SetupChange.swift in Sources */ = {isa = PBXBuildFile; fileRef = 12CD655083D4816F87B13463 /* SetupChange.swift */; };
+		2622474F63F391C3E102B5E5 /* SetupComparisonTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = BE36167100E59D7413C50F63 /* SetupComparisonTests.swift */; };
+		16097A41A1EF24BCF2F670DB /* Statistics/SetupComparisonCharts.swift in Sources */ = {isa = PBXBuildFile; fileRef = 174DD37A96993576E0E573C6 /* Statistics/SetupComparisonCharts.swift */; };
+		414E7082E6A6B9DA8CD11EF3 /* CurrentSetupViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 17C7C2227FAC0A9F7F570A01 /* CurrentSetupViewModel.swift */; };
+		D7DECBB118052B85680A241B /* SetupComparison.swift in Sources */ = {isa = PBXBuildFile; fileRef = D5E7CDB17CCE70885EE93850 /* SetupComparison.swift */; };
 		6D16FF26E7F84F97B5DB6A88 /* CurrentSetupView.swift in Sources */ = {isa = PBXBuildFile; fileRef = CFD4A26A23202AF2EA506FCF /* CurrentSetupView.swift */; };
 		D70F014FFB67BA58678452E9 /* SetupChangeTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 03EC166B8AD05800AFCD474E /* SetupChangeTests.swift */; };
 		C16F511B2B89363A00EFD7A1 /* SimpleInsulinDose.swift in Sources */ = {isa = PBXBuildFile; fileRef = C16F511A2B89363A00EFD7A1 /* SimpleInsulinDose.swift */; };
@@ -1378,6 +1382,10 @@
 		C16F51182B891DB600EFD7A1 /* StoredDataAlgorithmInput.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StoredDataAlgorithmInput.swift; sourceTree = "<group>"; };
 		C4C16D18C8806FF48331134C /* InsulinDeliveryHistory.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = InsulinDeliveryHistory.swift; sourceTree = "<group>"; };
 		12CD655083D4816F87B13463 /* SetupChange.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SetupChange.swift; sourceTree = "<group>"; };
+		BE36167100E59D7413C50F63 /* SetupComparisonTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SetupComparisonTests.swift; sourceTree = "<group>"; };
+		174DD37A96993576E0E573C6 /* Statistics/SetupComparisonCharts.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Statistics/SetupComparisonCharts.swift; sourceTree = "<group>"; };
+		17C7C2227FAC0A9F7F570A01 /* CurrentSetupViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CurrentSetupViewModel.swift; sourceTree = "<group>"; };
+		D5E7CDB17CCE70885EE93850 /* SetupComparison.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SetupComparison.swift; sourceTree = "<group>"; };
 		CFD4A26A23202AF2EA506FCF /* CurrentSetupView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CurrentSetupView.swift; sourceTree = "<group>"; };
 		03EC166B8AD05800AFCD474E /* SetupChangeTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SetupChangeTests.swift; sourceTree = "<group>"; };
 		C16F511A2B89363A00EFD7A1 /* SimpleInsulinDose.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SimpleInsulinDose.swift; sourceTree = "<group>"; };
@@ -1826,6 +1834,7 @@
 				C16F51182B891DB600EFD7A1 /* StoredDataAlgorithmInput.swift */,
 				C4C16D18C8806FF48331134C /* InsulinDeliveryHistory.swift */,
 				12CD655083D4816F87B13463 /* SetupChange.swift */,
+				D5E7CDB17CCE70885EE93850 /* SetupComparison.swift */,
 				C16F511A2B89363A00EFD7A1 /* SimpleInsulinDose.swift */,
 				C152B9F42C9C7D4A00ACBC06 /* AutomationHistoryEntry.swift */,
 				84213C882D94941000642E78 /* InsulinDeliveryLogEvent.swift */,
@@ -2157,6 +2166,7 @@
 				FEEDF0000000000000000004 /* Statistics/TimeInRangeBar.swift */,
 				747DA22B61531CCAAC79E86D /* Statistics/DailyInsulinChartView.swift */,
 				FEEDF0000000000000000003 /* Statistics/AGPChartView.swift */,
+				174DD37A96993576E0E573C6 /* Statistics/SetupComparisonCharts.swift */,
 				FEEDF0000000000000000002 /* Statistics/StatisticsView.swift */,
 				E4854073AAE5C2CB97167F63 /* HealthAccessView.swift */,
 				DDC389FB2A2BC6670066E2E8 /* SettingsView+algorithmExperimentsSection.swift */,
@@ -2663,6 +2673,7 @@
 				C11BD0542523CFED00236B08 /* SimpleBolusViewModel.swift */,
 				1DB1CA4E24A56D7600B3B94C /* SettingsViewModel.swift */,
 				FEEDF0000000000000000001 /* StatisticsViewModel.swift */,
+				17C7C2227FAC0A9F7F570A01 /* CurrentSetupViewModel.swift */,
 				1D49795724E7289700948F05 /* ServicesViewModel.swift */,
 				C174233B259BEB0F00399C9D /* ManualEntryDoseViewModel.swift */,
 				1DB619AB270BAD3D006C9D07 /* VersionUpdateViewModel.swift */,
@@ -2766,6 +2777,7 @@
 				C152B9F62C9C7EF100ACBC06 /* AutomationHistoryEntryTests.swift */,
 				F69CE2EE3714858772FE7A26 /* InsulinDeliveryHistoryTests.swift */,
 				03EC166B8AD05800AFCD474E /* SetupChangeTests.swift */,
+				BE36167100E59D7413C50F63 /* SetupComparisonTests.swift */,
 				FEEDF0000000000000000005 /* GlucoseStatisticsTests.swift */,
 				A9DFAFB224F0415E00950D1E /* CarbBackfillRequestUserInfoTests.swift */,
 				A963B279252CEBAE0062AA12 /* SetBolusUserInfoTests.swift */,
@@ -3713,6 +3725,7 @@
 				B4F3D25124AF890C0095CE44 /* BluetoothStateManager.swift in Sources */,
 				1DDE273D24AEA4B000796622 /* SettingsViewModel.swift in Sources */,
 				FEEDB0000000000000000001 /* StatisticsViewModel.swift in Sources */,
+				414E7082E6A6B9DA8CD11EF3 /* CurrentSetupViewModel.swift in Sources */,
 				DD3DBD292A33AFE9000F8B5B /* IntegralRetrospectiveCorrectionSelectionView.swift in Sources */,
 				A1B2C3D42E8F000100000002 /* GuardAndRunwaySelectionView.swift in Sources */,
 				842E40A72F22F7E2000CCCE0 /* TintedContent.swift in Sources */,
@@ -3767,6 +3780,7 @@
 				1D6B1B6726866D89009AC446 /* AlertPermissionsChecker.swift in Sources */,
 				52ECDA0F09B4C8F23A4B450E /* InsulinDeliveryHistory.swift in Sources */,
 				8879F70ABCDF1E10619547A4 /* SetupChange.swift in Sources */,
+				D7DECBB118052B85680A241B /* SetupComparison.swift in Sources */,
 				C16F511B2B89363A00EFD7A1 /* SimpleInsulinDose.swift in Sources */,
 				4F08DE8F1E7BB871006741EA /* CollectionType+Loop.swift in Sources */,
 				A9F703772489D8AA00C98AD8 /* PersistentDeviceLog+SimulatedCoreData.swift in Sources */,
@@ -3786,6 +3800,7 @@
 				FEEDB0000000000000000004 /* Statistics/TimeInRangeBar.swift in Sources */,
 				A3C9F155FD92DC188BD9A21F /* Statistics/DailyInsulinChartView.swift in Sources */,
 				FEEDB0000000000000000003 /* Statistics/AGPChartView.swift in Sources */,
+				16097A41A1EF24BCF2F670DB /* Statistics/SetupComparisonCharts.swift in Sources */,
 				FEEDB0000000000000000002 /* Statistics/StatisticsView.swift in Sources */,
 				BAF043BF0BC70EC99AE79F71 /* HealthAccessView.swift in Sources */,
 				A9B607B0247F000F00792BE4 /* UserNotifications+Loop.swift in Sources */,
@@ -4039,6 +4054,7 @@
 				C152B9F72C9C7EF100ACBC06 /* AutomationHistoryEntryTests.swift in Sources */,
 				30E4A68B8C914C5E4B245555 /* InsulinDeliveryHistoryTests.swift in Sources */,
 				D70F014FFB67BA58678452E9 /* SetupChangeTests.swift in Sources */,
+				2622474F63F391C3E102B5E5 /* SetupComparisonTests.swift in Sources */,
 				FEEDB0000000000000000005 /* GlucoseStatisticsTests.swift in Sources */,
 				A9DFAFB324F0415E00950D1E /* CarbBackfillRequestUserInfoTests.swift in Sources */,
 				A963B27A252CEBAE0062AA12 /* SetBolusUserInfoTests.swift in Sources */,

Loop/Models/SetupChange.swift

@@ -25,6 +25,8 @@ struct SetupChange: Equatable {
     var items: [Item]
     /// When the setup before this change started, as far as the records show.
     var previousDate: Date? = nil
+    /// The therapy settings were first entered, during onboarding.
+    var isInitialSetup = false
 
     /// Changes this close together are reported as one edit.
     static let groupingInterval = TimeInterval(hours: 1)
@@ -39,10 +41,24 @@ struct SetupChange: Equatable {
             insulinType = settings.insulinType
             return settings
         }
-        return zip(sorted, sorted.dropFirst()).compactMap { previous, current in
+        // Records without therapy settings are saved before onboarding, and occasionally later
+        guard let firstEntered = sorted.firstIndex(where: hasTherapySettings) else {
+            return []
+        }
+        let entered = sorted[firstEntered...].filter(hasTherapySettings)
+        var changes = zip(entered, entered.dropFirst()).compactMap { previous, current in
             let items = differences(from: previous, to: current)
             return items.isEmpty ? nil : SetupChange(date: current.date, isLowerBound: false, items: items)
         }
+        if firstEntered > 0 {
+            let initial = entered[0]
+            changes.insert(SetupChange(date: initial.date, isLowerBound: false, items: differences(from: sorted[firstEntered - 1], to: initial), isInitialSetup: true), at: 0)
+        }
+        return changes
+    }
+
+    private static func hasTherapySettings(_ settings: StoredSettings) -> Bool {
+        settings.basalRateSchedule != nil || settings.insulinSensitivitySchedule != nil || settings.carbRatioSchedule != nil
     }
 
     /// Experiments turned on or off between dosing decisions. Decisions from builds that didn't
@@ -70,6 +86,7 @@ struct SetupChange: Equatable {
     func merging(_ other: SetupChange) -> SetupChange {
         var merged = self
         merged.date = max(date, other.date)
+        merged.isInitialSetup = isInitialSetup || other.isInitialSetup
         for item in other.items where !merged.items.contains(item) {
             merged.items.append(item)
         }

Loop/Models/SetupComparison.swift

@@ -0,0 +1,70 @@
+//
+//  SetupComparison.swift
+//  Loop
+//
+//  Copyright © 2026 LoopKit Authors. All rights reserved.
+//
+
+import Foundation
+import LoopKit
+
+/// Outcomes since the last setup change, compared with the period before it.
+struct SetupComparison: Equatable {
+    struct Period: Equatable {
+        let start: Date
+        let end: Date
+        let glucose: GlucoseStatistics
+        /// Average insulin per day, or nil when the dose records don't cover the period.
+        let insulinPerDay: Double?
+
+        var days: Double { end.timeIntervalSince(start) / .days(1) }
+        var timeInRange: Double? { glucose.timeInRange.isEmpty ? nil : glucose.timeInRange[.target, default: 0] }
+        var timeBelowRange: Double? { glucose.timeInRange.isEmpty ? nil : glucose.timeInRange[.low, default: 0] + glucose.timeInRange[.veryLow, default: 0] }
+    }
+
+    static let beforeDuration = TimeInterval.days(14)
+    static let suggestedDuration = TimeInterval.days(14)
+    /// Less CGM data than this in a period makes its numbers unreliable.
+    static let minimumCGMActive = 0.7
+    static let minimumPeriod = TimeInterval.days(1)
+
+    let before: Period?
+    let after: Period
+    /// The setup is still in use, rather than replaced by a later change.
+    let isCurrent: Bool
+
+    /// The current setup's comparison is still settling until it has run for about two weeks.
+    var isSettling: Bool { isCurrent && after.days * .days(1) < Self.suggestedDuration }
+
+    /// Compares the setup `change` started, until `end` (the next change) or `now`, with the period before it.
+    init?(change: SetupChange,
+          end: Date? = nil,
+          samples: [StoredGlucoseSample],
+          insulinHistory: InsulinDeliveryHistory?,
+          now: Date,
+          calendar: Calendar = .current) {
+        let afterEnd = min(end ?? now, now)
+        guard !change.isLowerBound, afterEnd.timeIntervalSince(change.date) >= Self.minimumPeriod else {
+            return nil
+        }
+        isCurrent = end == nil
+        func period(_ start: Date, _ end: Date) -> Period {
+            Period(start: start,
+                   end: end,
+                   glucose: GlucoseStatistics(samples: samples, start: start, end: end, calendar: calendar),
+                   insulinPerDay: Self.insulinPerDay(insulinHistory, from: start, to: end))
+        }
+        after = period(change.date, afterEnd)
+
+        let beforeStart = max(change.date - Self.beforeDuration, change.previousDate ?? .distantPast)
+        let candidate = period(beforeStart, change.date)
+        before = change.date.timeIntervalSince(beforeStart) >= Self.minimumPeriod && candidate.glucose.percentActive >= Self.minimumCGMActive ? candidate : nil
+    }
+
+    private static func insulinPerDay(_ history: InsulinDeliveryHistory?, from start: Date, to end: Date) -> Double? {
+        guard let history, history.coverageStart <= start, end <= history.end else {
+            return nil
+        }
+        return history.totals(from: start, to: end).total / (end.timeIntervalSince(start) / .days(1))
+    }
+}

Loop/View Models/CurrentSetupViewModel.swift

@@ -0,0 +1,80 @@
+//
+//  CurrentSetupViewModel.swift
+//  Loop
+//
+//  Copyright © 2026 LoopKit Authors. All rights reserved.
+//
+
+import Foundation
+import LoopKit
+
+@MainActor
+final class CurrentSetupViewModel: ObservableObject {
+    @Published private(set) var history: SetupHistory?
+    /// The change whose setup is being compared; the latest by default.
+    @Published private(set) var selected: SetupChange?
+    @Published private(set) var comparison: SetupComparison?
+    /// Time in range for each change's setup, by change date.
+    @Published private(set) var timeInRange: [Date: Double] = [:]
+    @Published private(set) var isLoading = true
+
+    private let loadHistory: () async throws -> SetupHistory
+    private let glucoseStore: GlucoseStoreProtocol?
+    private let insulinDeliveryHistory: ((Int) async throws -> InsulinDeliveryHistory)?
+    private let cacheDuration: TimeInterval
+    private let now: () -> Date
+
+    private var samples: [StoredGlucoseSample] = []
+    private var insulin: InsulinDeliveryHistory?
+
+    init(selected: SetupChange?,
+         loadHistory: @escaping () async throws -> SetupHistory,
+         glucoseStore: GlucoseStoreProtocol?,
+         insulinDeliveryHistory: ((Int) async throws -> InsulinDeliveryHistory)?,
+         cacheDuration: TimeInterval = Bundle.main.localCacheDuration,
+         now: @escaping () -> Date = { Date() }) {
+        self.selected = selected
+        self.loadHistory = loadHistory
+        self.glucoseStore = glucoseStore
+        self.insulinDeliveryHistory = insulinDeliveryHistory
+        self.cacheDuration = cacheDuration
+        self.now = now
+    }
+
+    var isCurrentSelected: Bool {
+        selected != nil && selected == history?.latest
+    }
+
+    func load() async {
+        defer { isLoading = false }
+        guard let history = try? await loadHistory() else {
+            return
+        }
+        self.history = history
+        selected = history.latest
+        let end = now()
+        if let glucoseStore {
+            samples = (try? await glucoseStore.getGlucoseSamples(start: end - cacheDuration, end: end))?
+                .filter { !$0.isDisplayOnly && !$0.wasUserEntered } ?? []
+        }
+        insulin = try? await insulinDeliveryHistory?(Int((cacheDuration / .days(1)).rounded()))
+        timeInRange = Dictionary(uniqueKeysWithValues: history.changes.compactMap { change in
+            let stats = GlucoseStatistics(samples: samples, start: change.date, end: history.end(of: change) ?? end)
+            return stats.timeInRange.isEmpty ? nil : (change.date, stats.timeInRange[.target, default: 0])
+        })
+        compare()
+    }
+
+    func select(_ change: SetupChange) {
+        selected = change
+        compare()
+    }
+
+    private func compare() {
+        guard let selected, let history else {
+            comparison = nil
+            return
+        }
+        comparison = SetupComparison(change: selected, end: history.end(of: selected), samples: samples, insulinHistory: insulin, now: now())
+    }
+}