Append when the GeoFeed is retrieved and if it was generated from in memory cache

AS1024.GeoFeed/Controllers/GeofeedController.cs

@@ -36,10 +36,12 @@ namespace AS1024.GeoFeed.Controllers
         [Route("")]
         public async Task<IActionResult> Get()
         {
+            bool isCached = true;
             try
             {
                 if (!memoryCache.TryGetValue(GeoFeedCacheKey, out List<IPGeoFeed>? feed))
                 {
+                    isCached = false;
                     feed = await builder.GetGeoFeedData();
                     if (environment.IsProduction())
                     {
@@ -49,7 +51,7 @@ namespace AS1024.GeoFeed.Controllers
                     }
                 }
 
-                return ReturnFile(feed);
+                return ReturnFile(feed, isCached);
             } catch (HttpRequestException ex)
             {
                 logger.LogWarning($"Temporary failure of retrieving GeoData from upstream. {ex}");
@@ -66,9 +68,9 @@ namespace AS1024.GeoFeed.Controllers
         }
 
         [NonAction]
-        private IActionResult ReturnFile(List<IPGeoFeed>? feed)
+        private IActionResult ReturnFile(List<IPGeoFeed>? feed, bool isCached = false)
         {
-            string csvContent = feed.ToGeoFeedCsv(); // Assuming ToGeoFeedCsv() returns a string in CSV format.
+            string csvContent = feed.ToGeoFeedCsv(true, isCached); // Assuming ToGeoFeedCsv() returns a string in CSV format.
             return ReturnFile(csvContent);
         }