Add a feature to limit maximum Insulin On Board

Loop/Extensions/NSUserDefaults.swift

@@ -26,6 +26,7 @@ extension UserDefaults {
         case GlucoseTargetRangeSchedule = "com.loudnate.Naterade.GlucoseTargetRangeSchedule"
         case MaximumBasalRatePerHour = "com.loudnate.Naterade.MaximumBasalRatePerHour"
         case MaximumBolus = "com.loudnate.Naterade.MaximumBolus"
+        case MaximumIOB = "com.loudnate.Naterade.MaximumIOB"
         case PreferredInsulinDataSource = "com.loudnate.Loop.PreferredInsulinDataSource"
         case FetchEnliteDataEnabled = "com.loopkit.Loop.FetchEnliteDataEnabled"
         case PumpID = "com.loudnate.Naterade.PumpID"
@@ -151,6 +152,20 @@ extension UserDefaults {
             }
         }
     }
+    var maximumIOB: Double? {
+        get {
+            let value = double(forKey: Key.MaximumIOB.rawValue)
+
+            return value > 0 ? value : nil
+        }
+        set {
+            if let maximumIOB = newValue {
+                set(maximumIOB, forKey: Key.MaximumIOB.rawValue)
+            } else {
+                removeObject(forKey: Key.MaximumIOB.rawValue)
+            }
+        }
+    }
 
     var preferredInsulinDataSource: InsulinDataSource? {
         get {

Loop/Managers/AnalyticsManager.swift

@@ -107,6 +107,10 @@ final class AnalyticsManager {
         logEvent("Maximum bolus change")
     }
 
+    func didChangeMaximumIOB() {
+        logEvent("Maximum IOB change")
+    }
+
     func didChangeMinimumBGGuard() {
         logEvent("Minimum BG Guard change")
     }

Loop/Managers/DeviceDataManager.swift

@@ -964,6 +964,14 @@ final class DeviceDataManager: CarbStoreDelegate, DoseStoreDelegate, Transmitter
         }
     }
 
+    var maximumIOB: Double? = UserDefaults.standard.maximumIOB {
+        didSet {
+            UserDefaults.standard.maximumIOB = maximumIOB
+
+            AnalyticsManager.sharedManager.didChangeMaximumIOB()
+        }
+    }
+
     // MARK: - CarbKit
 
     let carbStore: CarbStore?

Loop/Managers/DoseMath.swift

@@ -11,7 +11,6 @@ import HealthKit
 import InsulinKit
 import LoopKit
 
-
 struct DoseMath {
     /// The allowed precision
     static let basalStrokes: Double = 40
@@ -59,9 +58,11 @@ struct DoseMath {
         atDate date: Date = Date(),
         lastTempBasal: DoseEntry?,
         maxBasalRate: Double,
+        maxIOB: Double,
         glucoseTargetRange: GlucoseRangeSchedule,
         insulinSensitivity: InsulinSensitivitySchedule,
         basalRateSchedule: BasalRateSchedule,
+        insulinOnBoard: Double?,
         minimumBGGuard: GlucoseThreshold
     ) -> (rate: Double, duration: TimeInterval)? {
         guard glucose.count > 1 else {
@@ -122,7 +123,13 @@ struct DoseMath {
                 duration = TimeInterval(0)
             }
         }
-
+        if  let iob = insulinOnBoard {
+            if iob > maxIOB {
+                // We hit the max IOB, cancel the one in progress.
+                rate = 0
+                duration = TimeInterval(0)
+            }
+        }
         if let rate = rate {
             return (rate: rate, duration: duration)
         } else {
@@ -147,9 +154,11 @@ struct DoseMath {
     static func recommendBolusFromPredictedGlucose(_ glucose: [GlucoseValue],
         atDate date: Date = Date(),
         maxBolus: Double,
+        maxIOB: Double,
         glucoseTargetRange: GlucoseRangeSchedule,
         insulinSensitivity: InsulinSensitivitySchedule,
         basalRateSchedule: BasalRateSchedule,
+        insulinOnBoard: Double?,
         pendingInsulin: Double,
         minimumBGGuard: GlucoseThreshold
     ) -> BolusRecommendation {
@@ -175,7 +184,7 @@ struct DoseMath {
         let roundedAmount = round(max(0, (doseUnits - pendingInsulin)) * 40) / 40
 
         // Cap at max bolus amount
-        let cappedAmount = min(maxBolus, max(0, roundedAmount))
+        var cappedAmount = min(maxBolus, max(0, roundedAmount))
 
         let notice: BolusRecommendationNotice?
         if cappedAmount > 0 && minGlucose.quantity.doubleValue(for: glucoseTargetRange.unit) < eventualGlucoseTargets.minValue {
@@ -187,7 +196,14 @@ struct DoseMath {
         } else {
             notice = nil
         }
-
+
+        // Cap at maxium iob, if provided.
+        if  let iob = insulinOnBoard {
+            if iob + cappedAmount + pendingInsulin > maxIOB, maxIOB > 0 {
+                cappedAmount = max(0, maxIOB - iob - pendingInsulin)
+            }
+        }
+
         return BolusRecommendation(amount: cappedAmount, pendingInsulin: pendingInsulin, notice: notice)
     }
 }

Loop/Managers/LoopDataManager.swift

@@ -571,6 +571,7 @@ final class LoopDataManager {
 
         guard let
             maxBasal = deviceDataManager.maximumBasalRatePerHour,
+            let maxIOB = deviceDataManager.maximumIOB,
             let glucoseTargetRange = deviceDataManager.glucoseTargetRangeSchedule,
             let insulinSensitivity = deviceDataManager.insulinSensitivitySchedule,
             let basalRates = deviceDataManager.basalRateSchedule
@@ -585,9 +586,11 @@ final class LoopDataManager {
             let tempBasal = DoseMath.recommendTempBasalFromPredictedGlucose(predictedGlucose,
                 lastTempBasal: lastTempBasal,
                 maxBasalRate: maxBasal,
+                maxIOB: maxIOB,
                 glucoseTargetRange: glucoseTargetRange,
                 insulinSensitivity: insulinSensitivity,
                 basalRateSchedule: basalRates,
+                insulinOnBoard: self.insulinOnBoard?.value,
                 minimumBGGuard: minimumBGGuard
             )
         else {
@@ -632,6 +635,7 @@ final class LoopDataManager {
             glucose = self.predictedGlucose,
             let glucoseWithoutMomentum = self.predictedGlucoseWithoutMomentum,
             let maxBolus = self.deviceDataManager.maximumBolus,
+            let maxIOB = self.deviceDataManager.maximumIOB,
             let glucoseTargetRange = self.deviceDataManager.glucoseTargetRangeSchedule,
             let insulinSensitivity = self.deviceDataManager.insulinSensitivitySchedule,
             let basalRates = self.deviceDataManager.basalRateSchedule
@@ -653,18 +657,22 @@ final class LoopDataManager {
 
         let recommendationWithMomentum = DoseMath.recommendBolusFromPredictedGlucose(glucose,
             maxBolus: maxBolus,
+            maxIOB: maxIOB,
             glucoseTargetRange: glucoseTargetRange,
             insulinSensitivity: insulinSensitivity,
             basalRateSchedule: basalRates,
+            insulinOnBoard: self.insulinOnBoard?.value,
             pendingInsulin: pendingInsulin,
             minimumBGGuard: minimumBGGuard
         )
 
         let recommendationWithoutMomentum = DoseMath.recommendBolusFromPredictedGlucose(glucoseWithoutMomentum,
             maxBolus: maxBolus,
+            maxIOB: maxIOB,
             glucoseTargetRange: glucoseTargetRange,
             insulinSensitivity: insulinSensitivity,
             basalRateSchedule: basalRates,
+            insulinOnBoard: self.insulinOnBoard?.value,
             pendingInsulin: pendingInsulin,
             minimumBGGuard: minimumBGGuard
         )

Loop/View Controllers/SettingsTableViewController.swift

@@ -112,6 +112,7 @@ final class SettingsTableViewController: UITableViewController, DailyValueSchedu
         case insulinSensitivity
         case maxBasal
         case maxBolus
+        case maxIOB
     }
 
     fileprivate enum ServiceRow: Int, CaseCountable {
@@ -334,8 +335,15 @@ final class SettingsTableViewController: UITableViewController, DailyValueSchedu
                 } else {
                     configCell.detailTextLabel?.text = TapToSetString
                 }
+            case .maxIOB:
+                configCell.textLabel?.text = NSLocalizedString("Maximum IOB", comment: "The title text for the maximum insulin-on-board value")
+
+                if let maxIOB = dataManager.maximumIOB {
+                    configCell.detailTextLabel?.text = "\(valueNumberFormatter.string(from: NSNumber(value: maxIOB))!) U"
+                } else {
+                    configCell.detailTextLabel?.text = TapToSetString
+                }
             }
-
             cell = configCell
         case .devices:
             let deviceCell = tableView.dequeueReusableCell(withIdentifier: RileyLinkDeviceTableViewCell.className) as! RileyLinkDeviceTableViewCell
@@ -406,9 +414,8 @@ final class SettingsTableViewController: UITableViewController, DailyValueSchedu
         switch Section(rawValue: indexPath.section)! {
         case .pump:
             let row = PumpRow(rawValue: indexPath.row)!
-            switch row {
-            case .pumpID:
-                let vc: TextFieldTableViewController
+            //switch row {
+                var vc: TextFieldTableViewController
                 switch row {
                 case .pumpID:
                     vc = PumpIDTableViewController(pumpID: dataManager.pumpID, region: dataManager.pumpState?.pumpRegion)
@@ -420,13 +427,15 @@ final class SettingsTableViewController: UITableViewController, DailyValueSchedu
                 vc.delegate = self
 
                 show(vc, sender: indexPath)
+            /*
             case .batteryChemistry:
                 let vc = RadioSelectionTableViewController.batteryChemistryType(dataManager.batteryChemistry)
                 vc.title = sender?.textLabel?.text
                 vc.delegate = self
 
                 show(vc, sender: sender)
             }
+ *          */
         case .cgm:
             let row = CGMRow(rawValue: indexPath.row)!
             switch row {
@@ -455,7 +464,7 @@ final class SettingsTableViewController: UITableViewController, DailyValueSchedu
         case .configuration:
             let row = ConfigurationRow(rawValue: indexPath.row)!
             switch row {
-            case .insulinActionDuration, .maxBasal, .maxBolus:
+            case .insulinActionDuration, .maxBasal, .maxBolus, .maxIOB:
                 let vc: TextFieldTableViewController
 
                 switch row {
@@ -465,6 +474,8 @@ final class SettingsTableViewController: UITableViewController, DailyValueSchedu
                     vc = .maxBasal(dataManager.maximumBasalRatePerHour)
                 case .maxBolus:
                     vc = .maxBolus(dataManager.maximumBolus)
+                case .maxIOB:
+                    vc = .maxIOB(dataManager.maximumIOB)
                 default:
                     fatalError()
                 }
@@ -862,9 +873,16 @@ extension SettingsTableViewController: TextFieldTableViewControllerDelegate {
                     } else {
                         dataManager.maximumBolus = nil
                     }
+                case .maxIOB:
+                    if let value = controller.value, let units = valueNumberFormatter.number(from: value)?.doubleValue {
+                        dataManager.maximumIOB = units
+                    } else {
+                        dataManager.maximumIOB = nil
+                    }
                 default:
                     assertionFailure()
                 }
+
             default:
                 assertionFailure()
             }

Loop/View Controllers/TextFieldTableViewController.swift

@@ -85,5 +85,20 @@ extension TextFieldTableViewController {
         }
 
         return vc
-    }    
+    }
+
+    static func maxIOB(_ value: Double?) -> T {
+        let vc = T()
+
+        vc.placeholder = NSLocalizedString("Enter a number of units", comment: "The placeholder text instructing users how to enter a maximum insulin on board")
+        vc.keyboardType = .decimalPad
+        vc.unit = NSLocalizedString("Units", comment: "The unit string for units")
+
+        if let maxIOB = value {
+            vc.value = valueNumberFormatter.string(from: NSNumber(value: maxIOB))
+        }
+
+        return vc
+    }
+
 }