Add aggregate API

Weather/Service/Models/WeatherAggregate.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using ChrisKaczor.HomeMonitor.Weather.Models;
+using JetBrains.Annotations;
+
+namespace ChrisKaczor.HomeMonitor.Weather.Service.Models
+{
+    [PublicAPI]
+    public class WeatherAggregate
+    {
+        public ReadingAggregate Humidity { get; set; }
+
+        public ReadingAggregate Temperature { get; set; }
+
+        public ReadingAggregate Pressure { get; set; }
+
+        public ReadingAggregate Light { get; set; }
+
+        public ReadingAggregate WindSpeed { get; set; }
+
+        public WindDirection WindDirectionAverage { get; set; }
+
+        public decimal RainTotal { get; set; }
+
+        private readonly static List<int> _windDirectionValues = ((WindDirection[])Enum.GetValues(typeof(WindDirection))).Select(e => (int)e).ToList();
+
+        public WeatherAggregate(IEnumerable<WeatherReading> readings)
+        {
+            if (!readings.Any())
+                return;
+
+            Humidity = new ReadingAggregate(readings, r => r.Humidity, 1);
+
+            Temperature = new ReadingAggregate(readings, r => r.PressureTemperature, 1);
+
+            Pressure = new ReadingAggregate(readings, r => r.Pressure, 2);
+
+            Light = new ReadingAggregate(readings, r => (r.LightLevel / 3.3m * 100).Truncate(1), 1);
+
+            WindSpeed = new ReadingAggregate(readings, r => r.WindSpeed, 1);
+
+            var windDirectionAverage = readings.Average(r => (decimal)r.WindDirection);
+            WindDirectionAverage = (WindDirection)_windDirectionValues.Aggregate((x, y) => Math.Abs(x - windDirectionAverage) < Math.Abs(y - windDirectionAverage) ? x : y);
+
+            RainTotal = readings.Sum(r => r.Rain);
+        }
+    }
+}