Catalog Lite

CatalogLite/ExpirationGuard.cs

@@ -0,0 +1,27 @@
+using System.Globalization;
+using System.Reflection;
+
+namespace CatalogLite;
+
+internal static class ExpirationGuard
+{
+    private const string MetadataKey = "CatalogLiteExpirationDate";
+
+    public static bool IsExpired(out DateOnly? expirationDate)
+    {
+        expirationDate = TryReadExpirationDate();
+        return expirationDate is null || DateOnly.FromDateTime(DateTime.Today) > expirationDate.Value;
+    }
+
+    private static DateOnly? TryReadExpirationDate()
+    {
+        var value = typeof(Program).Assembly
+            .GetCustomAttributes<AssemblyMetadataAttribute>()
+            .FirstOrDefault(attribute => string.Equals(attribute.Key, MetadataKey, StringComparison.Ordinal))
+            ?.Value;
+
+        return DateOnly.TryParseExact(value, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None, out var date)
+            ? date
+            : null;
+    }
+}