Merge pull request #935 from bastiaanv/fix/delta-mmoll

Fix mmol/L delta calculation

Trio/Sources/Modules/Home/View/Header/CurrentGlucoseView.swift

@@ -137,11 +137,14 @@ struct CurrentGlucoseView: View {
             return "--"
         }
 
-        let lastGlucose = glucose.last?.glucose ?? 0
-        let secondLastGlucose = glucose.first?.glucose ?? 0
+        var lastGlucose = Decimal(glucose.last?.glucose ?? 0)
+        var secondLastGlucose = Decimal(glucose.first?.glucose ?? 0)
+        if units == .mmolL {
+            lastGlucose = lastGlucose.asMmolL
+            secondLastGlucose = secondLastGlucose.asMmolL
+        }
         let delta = lastGlucose - secondLastGlucose
-        let deltaAsDecimal = units == .mmolL ? Decimal(delta).asMmolL : Decimal(delta)
-        return deltaFormatter.string(from: deltaAsDecimal as NSNumber) ?? "--"
+        return deltaFormatter.string(from: delta as NSNumber) ?? "--"
     }
 }
 

Trio/Sources/Services/LiveActivity/LiveActivityAttributes+Helper.swift

@@ -39,20 +39,25 @@ extension LiveActivityAttributes.ContentState {
 
     static func calculateChange(chart: [GlucoseData], units: GlucoseUnits) -> String {
         guard chart.count > 2 else { return "" }
-        let lastGlucose = chart.first?.glucose ?? 0
-        let secondLastGlucose = chart.dropFirst().first?.glucose ?? 0
-        let delta = lastGlucose - secondLastGlucose
-        let deltaAsDecimal = units == .mmolL ? Decimal(delta).asMmolL : Decimal(delta)
+
         let formatter = NumberFormatter()
         formatter.numberStyle = .decimal
         formatter.maximumFractionDigits = 1
+        formatter.positivePrefix = "  +"
+        formatter.negativePrefix = "  -"
+
+        var lastGlucose = Decimal(chart.first?.glucose ?? 0)
+        var secondLastGlucose = Decimal(chart.dropFirst().first?.glucose ?? 0)
         if units == .mmolL {
+            lastGlucose = lastGlucose.asMmolL
+            secondLastGlucose = secondLastGlucose.asMmolL
+
             formatter.minimumFractionDigits = 1
             formatter.maximumFractionDigits = 1
         }
-        formatter.positivePrefix = "  +"
-        formatter.negativePrefix = "  -"
-        return formatter.string(from: deltaAsDecimal as NSNumber) ?? "--"
+
+        let delta = lastGlucose - secondLastGlucose
+        return formatter.string(from: delta as NSNumber) ?? "--"
     }
 
     init(

Trio/Sources/Services/WatchManager/AppleWatchManager.swift

@@ -320,12 +320,14 @@ final class BaseWatchManager: NSObject, WCSessionDelegate, Injectable, WatchMana
 
                 // Calculate delta if we have at least 2 readings
                 if glucoseObjects.count >= 2 {
-                    var deltaValue = Decimal(glucoseObjects[0].glucose - glucoseObjects[1].glucose)
-
+                    var glucoseLast = Decimal(glucoseObjects[0].glucose)
+                    var glucoseSecondLast = Decimal(glucoseObjects[1].glucose)
                     if self.units == .mmolL {
-                        deltaValue = Double(truncating: deltaValue as NSNumber).asMmolL
+                        glucoseLast = glucoseLast.asMmolL
+                        glucoseSecondLast = glucoseSecondLast.asMmolL
                     }
-
+                    
+                    let deltaValue = glucoseLast - glucoseSecondLast
                     let formattedDelta = Formatter.glucoseFormatter(for: self.units)
                         .string(from: deltaValue as NSNumber) ?? "0"
                     watchState.delta = deltaValue < 0 ? "\(formattedDelta)" : "+\(formattedDelta)"