Use maxBolus to set automaticDosingIOBLimit

Loop/Managers/DoseMath.swift

@@ -234,7 +234,9 @@ extension Collection where Element: GlucoseValue {
         at date: Date,
         suspendThreshold: HKQuantity,
         sensitivity: HKQuantity,
-        model: InsulinModel
+        model: InsulinModel,
+        automaticDosingIOBLimit: Double?,
+        insulinOnBoard: Double?
     ) -> InsulinCorrection? {
         var minGlucose: GlucoseValue?
         var eventualGlucose: GlucoseValue?
@@ -328,8 +330,20 @@ extension Collection where Element: GlucoseValue {
                 units: units
             )
         } else if eventual.quantity > eventualGlucoseTargets.upperBound,
-            let minCorrectionUnits = minCorrectionUnits, let correctingGlucose = correctingGlucose
+            var minCorrectionUnits = minCorrectionUnits, let correctingGlucose = correctingGlucose
         {
+            // Limit automatic dosing to prevent insulinOnBoard > automaticDosingIOBLimit
+            if minCorrectionUnits > 0 &&
+                insulinOnBoard != nil &&
+                automaticDosingIOBLimit != nil &&
+                automaticDosingIOBLimit! > 0 {
+                let checkAutomaticDosing = automaticDosingIOBLimit! - (insulinOnBoard! + minCorrectionUnits)
+                if checkAutomaticDosing < 0 {
+                    // TO DO - nice to have logging but not required
+                    minCorrectionUnits = Swift.max(minCorrectionUnits+checkAutomaticDosing, 0)
+                }
+            }
+
             return .aboveRange(
                 min: min,
                 correcting: correctingGlucose,
@@ -371,14 +385,18 @@ extension Collection where Element: GlucoseValue {
         rateRounder: ((Double) -> Double)? = nil,
         isBasalRateScheduleOverrideActive: Bool = false,
         duration: TimeInterval = .minutes(30),
-        continuationInterval: TimeInterval = .minutes(11)
+        continuationInterval: TimeInterval = .minutes(11),
+        insulinOnBoard: Double?,
+        automaticDosingIOBLimit: Double?
     ) -> TempBasalRecommendation? {
         let correction = self.insulinCorrection(
             to: correctionRange,
             at: date,
             suspendThreshold: suspendThreshold ?? correctionRange.quantityRange(at: date).lowerBound,
             sensitivity: sensitivity.quantity(at: date),
-            model: model
+            model: model,
+            automaticDosingIOBLimit: automaticDosingIOBLimit,
+            insulinOnBoard: insulinOnBoard
         )
 
         let scheduledBasalRate = basalRates.value(at: date)
@@ -439,14 +457,18 @@ extension Collection where Element: GlucoseValue {
         rateRounder: ((Double) -> Double)? = nil,
         isBasalRateScheduleOverrideActive: Bool = false,
         duration: TimeInterval = .minutes(30),
-        continuationInterval: TimeInterval = .minutes(11)
+        continuationInterval: TimeInterval = .minutes(11),
+        insulinOnBoard: Double?,
+        automaticDosingIOBLimit: Double?
     ) -> AutomaticDoseRecommendation? {
         guard let correction = self.insulinCorrection(
             to: correctionRange,
             at: date,
             suspendThreshold: suspendThreshold ?? correctionRange.quantityRange(at: date).lowerBound,
             sensitivity: sensitivity.quantity(at: date),
-            model: model
+            model: model,
+            automaticDosingIOBLimit: automaticDosingIOBLimit,
+            insulinOnBoard: insulinOnBoard
         ) else {
             return nil
         }
@@ -516,7 +538,9 @@ extension Collection where Element: GlucoseValue {
             at: date,
             suspendThreshold: suspendThreshold ?? correctionRange.quantityRange(at: date).lowerBound,
             sensitivity: sensitivity.quantity(at: date),
-            model: model
+            model: model,
+            automaticDosingIOBLimit: nil,
+            insulinOnBoard: nil
         ) else {
             return ManualBolusRecommendation(amount: 0, pendingInsulin: pendingInsulin)
         }

Loop/Managers/LoopDataManager.swift

@@ -1616,6 +1616,9 @@ extension LoopDataManager {
 
             let dosingRecommendation: AutomaticDoseRecommendation?
 
+            // automaticDosingIOBLimit calculated from the user entered maxBolus
+            let automaticDosingIOBLimit = maxBolus! * 2.0
+
             switch settings.automaticDosingStrategy {
             case .automaticBolus:
                 let volumeRounder = { (_ units: Double) in
@@ -1634,7 +1637,9 @@ extension LoopDataManager {
                     lastTempBasal: lastTempBasal,
                     volumeRounder: volumeRounder,
                     rateRounder: rateRounder,
-                    isBasalRateScheduleOverrideActive: settings.scheduleOverride?.isBasalRateScheduleOverriden(at: startDate) == true
+                    isBasalRateScheduleOverrideActive: settings.scheduleOverride?.isBasalRateScheduleOverriden(at: startDate) == true,
+                    insulinOnBoard: dosingDecision.insulinOnBoard?.value,
+                    automaticDosingIOBLimit: automaticDosingIOBLimit
                 )
             case .tempBasalOnly:
                 let temp = predictedGlucose.recommendedTempBasal(
@@ -1647,7 +1652,9 @@ extension LoopDataManager {
                     maxBasalRate: maxBasal!,
                     lastTempBasal: lastTempBasal,
                     rateRounder: rateRounder,
-                    isBasalRateScheduleOverrideActive: settings.scheduleOverride?.isBasalRateScheduleOverriden(at: startDate) == true
+                    isBasalRateScheduleOverrideActive: settings.scheduleOverride?.isBasalRateScheduleOverriden(at: startDate) == true,
+                    insulinOnBoard: dosingDecision.insulinOnBoard?.value,
+                    automaticDosingIOBLimit: automaticDosingIOBLimit
                 )
                 dosingRecommendation = AutomaticDoseRecommendation(basalAdjustment: temp)
             }