Initial work on getting minimal API to work

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

@@ -7,6 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Http" Version="8.0.0" />

AS1024.GeoFeed.Core/CacheService/GeoFeedCacheService.cs

@@ -0,0 +1,58 @@
+using AS1024.GeoFeed.Core.Interfaces;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace AS1024.GeoFeed.Core.CacheService
+{
+    public class GeoFeedCacheService : IHostedService
+    {
+        private readonly ILogger<GeoFeedCacheService> logger;
+        private readonly IGeoFeedProvider feedProvider;
+        private readonly IHost host;
+
+        public GeoFeedCacheService(ILogger<GeoFeedCacheService> logger,
+        IGeoFeedProvider feedProvider,
+        IHost host)
+        {
+            this.logger = logger;
+            this.feedProvider = feedProvider;
+            this.host = host;
+        }
+
+        public Task StartAsync(CancellationToken cancellationToken)
+        {
+            _ = StartPerioidicSync(cancellationToken);
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync(CancellationToken cancellationToken)
+        {
+            return Task.CompletedTask;
+        }
+
+        public async Task<bool> StartPerioidicSync(CancellationToken Token)
+        {
+            while (!Token.IsCancellationRequested)
+            {
+                try
+                {
+                    var scope = host.Services.CreateScope();
+
+                    var persistentCacheProvider = 
+                        scope.ServiceProvider.GetRequiredService<IGeoFeedPersistentCacheProvider>();
+
+                    var results = await feedProvider.GetGeoFeedData();
+                    await persistentCacheProvider.CacheGeoFeed(results);
+                }
+                catch (Exception)
+                {
+                    logger.LogWarning("On disk cache failed to run. Waiting on 30 minutes before retry...");
+                }
+                await Task.Delay(TimeSpan.FromMinutes(30));
+            }
+
+            return false;
+        }
+    }
+}

AS1024.GeoFeed.Core/CacheService/GeoFeedLocalFileCache.cs

@@ -0,0 +1,55 @@
+using AS1024.GeoFeed.Core.Interfaces;
+using AS1024.GeoFeed.Models;
+using AS1024.GeoFeed.Core.Tools;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+
+namespace AS1024.GeoFeed.Core.CacheService
+{
+    public class GeoFeedLocalFileCache : IGeoFeedPersistentCacheProvider
+    {
+        private readonly IConfiguration configuration;
+        private readonly ILogger<GeoFeedLocalFileCache> logger;
+
+        public GeoFeedLocalFileCache(IConfiguration _configuration,
+            ILogger<GeoFeedLocalFileCache> logger)
+        {
+            configuration = _configuration;
+            this.logger = logger;
+        }
+
+        string IGeoFeedPersistentCacheProvider.ProviderName => "file";
+
+        Task<bool> IGeoFeedPersistentCacheProvider.CacheGeoFeed(IList<IPGeoFeed> pGeoFeeds)
+        {
+            string? tempPath = GetTempPath();
+            logger.LogInformation($"Writing geofeed data to: {tempPath}");
+            File.WriteAllText(tempPath, pGeoFeeds.ToList().
+                ToGeoFeedCsv());
+
+            return Task.FromResult(true);
+        }
+
+        private string GetTempPath()
+        {
+            string? tempPath = Path.Combine(Path.GetTempPath(), "geoFeedCache.csv");
+
+            logger.LogInformation($"Getting GeoFeed data from: {tempPath}");
+
+            if (!string.IsNullOrEmpty(configuration["TempCache"]))
+                tempPath = configuration["TempCache"];
+            return tempPath;
+        }
+
+        string IGeoFeedPersistentCacheProvider.GetGeoFeed()
+        {
+            return File.ReadAllText(GetTempPath());
+        }
+    }
+}

AS1024.GeoFeed.Core/GeoFeedPreloader/PreloadGeoFeed.cs

@@ -0,0 +1,54 @@
+using AS1024.GeoFeed.Core.Interfaces;
+using AS1024.GeoFeed.Models;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace AS1024.GeoFeed.Core.GeoFeedPreloader
+{
+    public class PreLoadGeoFeed : IHostedService
+    {
+        private readonly ILogger<PreLoadGeoFeed> logger;
+        private readonly IGeoFeedProvider provider;
+        private readonly IMemoryCache memoryCache;
+        private readonly IHostEnvironment environment;
+        private const string GeoFeedCacheKey = "GeoFeedData";
+
+        public PreLoadGeoFeed(ILogger<PreLoadGeoFeed> logger,
+            IGeoFeedProvider provider,
+            IMemoryCache memoryCache,
+            IHostEnvironment environment)
+        {
+            this.logger = logger;
+            this.provider = provider;
+            this.memoryCache = memoryCache;
+            this.environment = environment;
+        }
+
+        async Task IHostedService.StartAsync(CancellationToken cancellationToken)
+        {
+            try
+            {
+                if (environment.IsProduction())
+                    await StartPreLoad();
+            }
+            catch (Exception ex)
+            {
+                logger.LogWarning($"Failed to preload, exception settings below:\n{ex}");
+            }
+        }
+
+        private async Task StartPreLoad()
+        {
+            logger.LogInformation("Preloading GeoFeed data in memory...");
+            List<IPGeoFeed> feed = await provider.GetGeoFeedData();
+            MemoryCacheEntryOptions cacheEntryOptions = new MemoryCacheEntryOptions().SetAbsoluteExpiration(TimeSpan.FromMinutes(45));
+            memoryCache.Set(GeoFeedCacheKey, feed, cacheEntryOptions);
+        }
+
+        Task IHostedService.StopAsync(CancellationToken cancellationToken)
+        {
+            return Task.CompletedTask;
+        }
+    }
+}

AS1024.GeoFeed.Core/Interfaces/IGeoFeedCacheProvider.cs

@@ -0,0 +1,31 @@
+using AS1024.GeoFeed.Models;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AS1024.GeoFeed.Core.Interfaces
+{
+    /// <summary>
+    /// Represents a persistent cache GeoFeed provider
+    /// </summary>
+    public interface IGeoFeedPersistentCacheProvider
+    {
+        /// <summary>
+        /// Name of the provider
+        /// </summary>
+        public string ProviderName { get; }
+        /// <summary>
+        /// Returns the GeoFeed
+        /// </summary>
+        /// <returns>String of the CSV geofeed</returns>
+        public string GetGeoFeed();
+        /// <summary>
+        /// Stores the GeoFeed in the cache backend
+        /// </summary>
+        /// <param name="pGeoFeeds">GeoFeed retrieved from the backend</param>
+        /// <returns></returns>
+        public Task<bool> CacheGeoFeed(IList<IPGeoFeed> pGeoFeeds);
+    }
+}