Adding Flags API

src/api/MicCheck.Api/Features/FlagCache.cs

@@ -0,0 +1,22 @@
+using Microsoft.Extensions.Caching.Memory;
+
+namespace MicCheck.Api.Features;
+
+public class FlagCache(IMemoryCache cache)
+{
+    private static readonly TimeSpan CacheDuration = TimeSpan.FromSeconds(60);
+
+    public IReadOnlyList<FeatureStateResult>? Get(int environmentId)
+    {
+        cache.TryGetValue(CacheKey(environmentId), out IReadOnlyList<FeatureStateResult>? flags);
+        return flags;
+    }
+
+    public void Set(int environmentId, IReadOnlyList<FeatureStateResult> flags)
+        => cache.Set(CacheKey(environmentId), flags, CacheDuration);
+
+    public void Invalidate(int environmentId)
+        => cache.Remove(CacheKey(environmentId));
+
+    private static string CacheKey(int environmentId) => $"flags:{environmentId}";
+}