added an endpoint that provides the latest occupancy estimation

CentralHub.Api.Model/Responses/Measurements/GetLatestOccupancyResponse.cs

@@ -0,0 +1,27 @@
+using System.Text.Json.Serialization;
+
+namespace CentralHub.Api.Model.Responses.AggregatedMeasurements;
+
+public sealed class GetLatestOccupancyResponse
+{
+    [JsonConstructor]
+    public GetLatestOccupancyResponse(int? occupancy, bool success)
+    {
+        EstimatedOccupancy = occupancy;
+        Success = success;
+    }
+
+    public bool Success { get; }
+
+    public int? EstimatedOccupancy { get; }
+
+    public static GetLatestOccupancyResponse CreateUnsuccessful()
+    {
+        return new GetLatestOccupancyResponse(null, false);
+    }
+
+    public static GetLatestOccupancyResponse CreateSuccessful(int occupancy)
+    {
+        return new GetLatestOccupancyResponse(occupancy, true);
+    }
+}

CentralHub.Api/Controllers/MeasurementController.cs

@@ -87,7 +87,29 @@ public async Task<GetFirstAggregatedMeasurementsDateTimeResponse> GetFirstAggreg
         return GetFirstAggregatedMeasurementsDateTimeResponse.CreateSuccessful(possibleFirstDateTime.Value);
     }
 
-    private static IReadOnlyList<AggregatedMeasurements> CreateMeasurements(IReadOnlyCollection<AggregatedMeasurementDto> aggregatedMeasurements)
+    [HttpGet("occupancy/latest")]
+    public async Task<GetLatestOccupancyResponse> GetLatestEstimatedOccupancy(
+        int roomId, 
+        float wifiDevicesPerPerson, 
+        float bluetoothDevicesPerPerson,
+        CancellationToken cancellationToken)
+    {
+        var aggregatedMeasurements = (await measurementRepository.GetAggregatedMeasurementsAsync(roomId, cancellationToken)).Last();
+
+        if (aggregatedMeasurements == null)
+        {
+            return GetLatestOccupancyResponse.CreateUnsuccessful();
+        }
+
+        var occupancy = 
+            (int)Math.Round(
+            bluetoothDevicesPerPerson == 0 ? 0 : aggregatedMeasurements.BluetoothCount / bluetoothDevicesPerPerson + 
+            wifiDevicesPerPerson == 0 ? 0 : aggregatedMeasurements.BluetoothCount / wifiDevicesPerPerson);
+
+        return GetLatestOccupancyResponse.CreateSuccessful(occupancy);
+    }
+
+    private static IReadOnlyList<AggregatedMeasurements> CreateMeasurements(IEnumerable<AggregatedMeasurementDto> aggregatedMeasurements)
     {
         var recentAggregatedMeasurements = aggregatedMeasurements
             .Where(am => am.EndTime > (DateTime.UtcNow - TimeSpan.FromDays(1)))