World microapi

microservices/WorldApi/Services/WorldCycleService.cs

@@ -0,0 +1,56 @@
+using WorldApi.Models;
+
+namespace WorldApi.Services;
+
+public class WorldCycleService
+{
+    private readonly double _dayLengthSeconds;
+    private readonly DateTime _epochUtc;
+
+    public WorldCycleService(IConfiguration configuration)
+    {
+        _dayLengthSeconds = Math.Max(1.0, configuration.GetValue<double?>("WorldCycle:DayLengthSeconds") ?? 1200.0);
+
+        var configuredEpoch = configuration["WorldCycle:EpochUtc"];
+        _epochUtc = DateTime.TryParse(
+            configuredEpoch,
+            null,
+            System.Globalization.DateTimeStyles.AdjustToUniversal | System.Globalization.DateTimeStyles.AssumeUniversal,
+            out var parsedEpoch)
+            ? parsedEpoch
+            : new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+    }
+
+    public WorldCycleResponse GetCurrentCycle()
+    {
+        var now = DateTime.UtcNow;
+        var elapsedSeconds = Math.Max(0.0, (now - _epochUtc).TotalSeconds);
+        var timeOfDaySeconds = elapsedSeconds % _dayLengthSeconds;
+        var normalized = timeOfDaySeconds / _dayLengthSeconds;
+        var solarCurve = Math.Sin(normalized * Math.PI);
+        var lightLevel = Math.Clamp(solarCurve, 0.0, 1.0);
+
+        return new WorldCycleResponse
+        {
+            CurrentUtc = now,
+            DayLengthSeconds = _dayLengthSeconds,
+            TimeOfDaySeconds = timeOfDaySeconds,
+            TimeOfDayNormalized = normalized,
+            Phase = ResolvePhase(normalized),
+            IsDay = lightLevel > 0.0,
+            LightLevel = lightLevel
+        };
+    }
+
+    private static string ResolvePhase(double normalized)
+    {
+        return normalized switch
+        {
+            < 0.20 => "night",
+            < 0.30 => "dawn",
+            < 0.70 => "day",
+            < 0.80 => "dusk",
+            _ => "night"
+        };
+    }
+}