Fix calculation for meditation minutes

BeeKit/HeathKit/MindfulSessionHealthKitMetric.swift

@@ -8,8 +8,46 @@ class MindfulSessionHealthKitMetric : CategoryHealthKitMetric {
         super.init(humanText: humanText, databaseString: databaseString, category: category, hkSampleType: HKObjectType.categoryType(forIdentifier: .mindfulSession)!)
     }
 
-    override func valueInAppropriateUnits(rawValue: Double) -> Double {
-        return rawValue / minuteInSeconds
+    override func hkDatapointValueForSamples(samples: [HKSample], startOfDate: Date) -> Double {
+        let endOfDate = startOfDate.addingTimeInterval(24 * 60 * 60)
+
+        let orderedSamples = samples.sorted(by: { $0.startDate < $1.startDate })
+
+        var spanStart: Optional<Date> = nil
+        var spanEnd: Optional<Date> = nil
+        var totalSeconds = 0.0
+
+        for sample in orderedSamples {
+            if sample.hasUndeterminedDuration {
+                continue
+            }
+
+            let sampleStart = max(sample.startDate, startOfDate)
+            let sampleEnd = min(sample.endDate, endOfDate)
+
+            if let start = spanStart, let end = spanEnd {
+                // There is an existing span to examine
+                if sampleStart <= end {
+                    // If the sample overlaps with the current span, extend the span
+                    spanEnd = max(end, sampleEnd)
+                } else {
+                    // Otherwise, add the span to the total and start a new span
+                    totalSeconds += end.timeIntervalSince(start)
+                    spanStart = sampleStart
+                    spanEnd = sampleEnd
+                }
+            } else {
+                // No prior span, start with this one
+                spanStart = sampleStart
+                spanEnd = sampleEnd
+            }
+        }
+        if let end = spanEnd {
+            totalSeconds += end.timeIntervalSince(spanStart!)
+        }
+
+        let totalMinutes = totalSeconds / minuteInSeconds
+        return totalMinutes.rounded()
     }
 
     override func units(healthStore : HKHealthStore) async throws -> HKUnit {