Unify logic of generating the webside unlike a different version we had for MVC and Minimal API

AS1024.GeoFeed.Core/AS1024.GeoFeed.Core.csproj

@@ -1,9 +1,10 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
 
   <ItemGroup>

AS1024.GeoFeed.Core/GeoFeedLogic/GeoFeedReturn.cs

@@ -0,0 +1,70 @@
+using System.Text;
+using AS1024.GeoFeed.Core.Interfaces;
+using AS1024.GeoFeed.Core.Tools;
+using AS1024.GeoFeed.Models;
+using Microsoft.Extensions.Caching.Memory;
+
+namespace AS1024.GeoFeed.Core.GeoFeedLogic
+{
+    public class GeoFeedReturn
+    {
+        private const string GeoFeedCacheKey = "GeoFeedData";
+        private readonly IGeoFeedProvider provider;
+        private readonly ILogger<GeoFeedReturn> logger;
+        private readonly IGeoFeedPersistentCacheProvider cacheProvider;
+        private readonly IMemoryCache memoryCache;
+        private readonly IWebHostEnvironment environment;
+
+        public GeoFeedReturn(IGeoFeedProvider provider,
+                ILogger<GeoFeedReturn> logger,
+                IGeoFeedPersistentCacheProvider cacheProvider,
+                IMemoryCache memoryCache,
+                IWebHostEnvironment environment)
+        {
+            this.provider = provider;
+            this.logger = logger;
+            this.cacheProvider = cacheProvider;
+            this.memoryCache = memoryCache;
+            this.environment = environment;
+        }
+
+        public async Task<IResult> GetGeoFeed()
+        {
+            bool isCached = true;
+            try
+            {
+                if (!memoryCache.TryGetValue(GeoFeedCacheKey, out List<IPGeoFeed>? feed))
+                {
+                    isCached = false;
+                    feed = await provider.GetGeoFeedData();
+                    if (environment.IsProduction())
+                    {
+                        MemoryCacheEntryOptions cacheEntryOptions = new MemoryCacheEntryOptions()
+                            .SetSlidingExpiration(TimeSpan.FromMinutes(15));
+                        memoryCache.Set(GeoFeedCacheKey, feed, cacheEntryOptions);
+                    }
+                }
+
+                return Results.File(Encoding.UTF8.GetBytes(feed.ToGeoFeedCsv(true, isCached)),
+                                        "text/csv",
+                                        "geofeed.csv");
+
+            }
+            catch (HttpRequestException ex)
+            {
+                logger.LogWarning($"Temporary failure of retrieving GeoData from upstream. {ex}");
+                string geoFeedData = cacheProvider.GetGeoFeed();
+
+                return Results.File(Encoding.UTF8.GetBytes(geoFeedData),
+                    "text/csv",
+                    "geofeed.csv");
+            }
+            catch (Exception ex)
+            {
+                logger.LogError($"Error: {ex}");
+            }
+
+            return Results.NoContent();
+        }
+    }
+}