Rewrite electricity server to .NET web api

src/Electricity.Api/Models/Day.cs

@@ -0,0 +1,36 @@
+namespace Electricity.Api.Models;
+
+public record Day(uint DateTime, double TotalPowerUse, double TotalPowerReturn, double TotalGasUse)
+{
+    public static Day Empty(DateOnly date)
+    {
+        return new Day(
+            ConvertToEpoch(date.ToDateTime(new TimeOnly(0, 0), DateTimeKind.Utc)),
+            0, 0, 0);
+    }
+
+    public static Day FromEntity(Entities.ElectricityLog entity)
+    {
+        return new Day(
+            DateTime: ConvertToEpoch(ParseEntityDateTime(entity.Date, entity.TimeUtc)),
+            TotalPowerUse: entity.TotalPowerConsumptionDay + entity.TotalPowerConsumptionNight,
+            TotalPowerReturn: entity.TotalPowerReturnDay + entity.TotalPowerReturnNight,
+            TotalGasUse: entity.GasConsumptionInCubicMeters
+        );
+    }
+
+    private static DateTime ParseEntityDateTime(string date, string timeUtc)
+    {
+        return System.DateTime
+            .Parse(
+                $"{date}T{timeUtc}Z",
+                null,
+                System.Globalization.DateTimeStyles.AssumeUniversal)
+            .ToUniversalTime();
+    }
+
+    private static uint ConvertToEpoch(DateTime dateTime)
+    {
+        return (uint)Math.Round((dateTime - System.DateTime.UnixEpoch).TotalSeconds);
+    }
+};