From e8152186c1682d579440c363aa20c75328bbb2d2 Mon Sep 17 00:00:00 2001
From: Jeff Leung <jleung@v10networks.ca>
Date: Sat, 13 Jan 2024 17:05:21 -0800
Subject: [PATCH] Bring the caching services over

---
 AS1024.GeoFeed.MinimalAPI/Program.cs | 35 ++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/AS1024.GeoFeed.MinimalAPI/Program.cs b/AS1024.GeoFeed.MinimalAPI/Program.cs
index 4bc44c5..a6cf784 100644
--- a/AS1024.GeoFeed.MinimalAPI/Program.cs
+++ b/AS1024.GeoFeed.MinimalAPI/Program.cs
@@ -1,19 +1,25 @@
+using AS1024.GeoFeed.Core.CacheService;
 using AS1024.GeoFeed.Core.GeoFeedProviders;
 using AS1024.GeoFeed.Core.Interfaces;
 using AS1024.GeoFeed.Core.Tools;
 using AS1024.GeoFeed.Models;
 using Microsoft.AspNetCore.Http.HttpResults;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Caching.Memory;
+using System;
 using System.Text.Json.Serialization;
 
 namespace AS1024.GeoFeed.MinimalAPI
 {
     public class Program
     {
+
         public static void Main(string[] args)
         {
             var builder = WebApplication.CreateSlimBuilder(args);
             builder.Services.AddTransient<IGeoFeedProvider, NetboxAoTGeoFeedProvider>();
+            builder.Services.AddHostedService<GeoFeedCacheService>();
+            builder.Services.AddTransient<IGeoFeedPersistentCacheProvider, GeoFeedLocalFileCache>();
             builder.Services.AddMemoryCache();
             builder.Services.AddLogging();
             builder.Services.AddHttpClient();
@@ -21,14 +27,33 @@ namespace AS1024.GeoFeed.MinimalAPI
                 options.SerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default);
             });
             var app = builder.Build();
-            var geoFeed = app.Map("/geofeed.csv", async (IGeoFeedProvider provider, ILogger<Program> logger) => {
+            var geoFeed = app.Map("/geofeed.csv", async (IGeoFeedProvider provider, 
+                ILogger<Program> logger, 
+                IGeoFeedPersistentCacheProvider cacheProvider,
+                IMemoryCache memoryCache,
+                IWebHostEnvironment environment) => {
                 try
                 {
-                    var results =
-                    await provider.GetGeoFeedData();
-                    return results.ToGeoFeedCsv();
+                    if (!memoryCache.TryGetValue("Geofeed", out List<IPGeoFeed>? feed))
+                    {
+                        feed = await provider.GetGeoFeedData();
+                        if (environment.IsProduction())
+                        {
+                            MemoryCacheEntryOptions cacheEntryOptions = new MemoryCacheEntryOptions()
+                                .SetSlidingExpiration(TimeSpan.FromMinutes(15));
+                            memoryCache.Set("Geofeed", feed, cacheEntryOptions);
+                        }
+                    }
+
+                    return feed.ToGeoFeedCsv();
                 }
-                catch (Exception ex)
+                catch (HttpRequestException ex)
+                {
+                    logger.LogWarning($"Temporary failure of retrieving GeoData from upstream. {ex}");
+                    string geoFeedData = cacheProvider.GetGeoFeed();
+                    return geoFeedData;
+                }
+                    catch (Exception ex)
                 {
                     logger.LogError($"Error: {ex}");
                 }