Add aggregate API

Weather/Service/Controllers/ReadingsController.cs

@@ -32,6 +32,14 @@ namespace ChrisKaczor.HomeMonitor.Weather.Service.Controllers
             return (await _database.GetReadingHistory(start, end)).ToList();
         }
 
+        [HttpGet("aggregate")]
+        public async Task<ActionResult<WeatherAggregate>> GetHistoryAggregate(DateTimeOffset start, DateTimeOffset end)
+        {
+            var readings = await _database.GetReadingHistory(start, end);
+
+            return new WeatherAggregate(readings);
+        }
+
         [HttpGet("value-history")]
         public async Task<ActionResult<List<WeatherValue>>> GetValueHistory(WeatherValueType weatherValueType, DateTimeOffset start, DateTimeOffset end)
         {

Weather/Service/Extensions.cs

@@ -1,4 +1,5 @@
 using System;
+using DecimalMath;
 
 namespace ChrisKaczor.HomeMonitor.Weather.Service
 {
@@ -8,5 +9,10 @@ namespace ChrisKaczor.HomeMonitor.Weather.Service
         {
             return item.CompareTo(start) >= 0 && item.CompareTo(end) <= 0;
         }
+
+        public static decimal Truncate(this decimal value, int decimalPlaces)
+        {
+            return decimal.Truncate(value * DecimalEx.Pow(10, decimalPlaces)) / DecimalEx.Pow(10, decimalPlaces);
+        }
     }
 }

Weather/Service/Models/ReadingAggregate.cs

@@ -0,0 +1,25 @@
+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 ReadingAggregate
+    {
+        public decimal Min { get; set; }
+
+        public decimal Max { get; set; }
+
+        public decimal Average { get; set; }
+
+        public ReadingAggregate(IEnumerable<WeatherReading> readings, Func<WeatherReading, decimal> selector, int decimalPlaces)
+        {
+            Min = readings.Min(selector);
+            Max = readings.Max(selector);
+            Average = readings.Average(selector).Truncate(decimalPlaces);
+        }
+    }
+}

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);
+        }
+    }
+}