From d2a110024fa15944946561cc42ffb6c18b2c290a Mon Sep 17 00:00:00 2001
From: Maksym Pavlenko <pavlenko.maksym@gmail.com>
Date: Wed, 18 Jan 2017 18:05:27 -0800
Subject: [PATCH] Move feeds caching logic inside FeedService

---
 src/Podsync/Controllers/FeedController.cs | 60 ++++++++++-------------
 src/Podsync/Services/Rss/FeedService.cs   | 22 ++++++++-
 src/Podsync/Services/Rss/IFeedService.cs  |  8 ++-
 3 files changed, 52 insertions(+), 38 deletions(-)

diff --git a/src/Podsync/Controllers/FeedController.cs b/src/Podsync/Controllers/FeedController.cs
index fcaf435..8986fe8 100644
--- a/src/Podsync/Controllers/FeedController.cs
+++ b/src/Podsync/Controllers/FeedController.cs
@@ -27,13 +27,11 @@ namespace Podsync.Controllers
 
         private readonly ILinkService _linkService;
         private readonly IFeedService _feedService;
-        private readonly IStorageService _storageService;
 
-        public FeedController(IRssBuilder rssBuilder, ILinkService linkService, IStorageService storageService, IFeedService feedService, IStorageService storageService1)
+        public FeedController(IRssBuilder rssBuilder, ILinkService linkService, IFeedService feedService)
         {
             _linkService = linkService;
             _feedService = feedService;
-            _storageService = storageService1;
         }
 
         [HttpPost]
@@ -75,41 +73,33 @@ namespace Podsync.Controllers
         [ValidateModelState]
         public async Task<IActionResult> Feed([Required] string feedId)
         {
-            var serializedFeed = await _storageService.GetCached(Constants.Cache.FeedsPrefix, feedId);
-
-            if (string.IsNullOrEmpty(serializedFeed))
+            try
             {
-                Feed feed;
-
-                try
-                {
-                    feed = await _feedService.Get(feedId);
-                }
-                catch (KeyNotFoundException)
-                {
-                    return NotFound($"ERROR: No feed with id {feedId}");
-                }
-
-                var selfHost = Request.GetBaseUrl();
-
-                // Set atom link to this feed
-                // See https://validator.w3.org/feed/docs/warning/MissingAtomSelfLink.html
-                var selfLink = new Uri(selfHost, Request.Path);
-                feed.Channels.ForEach(x => x.AtomLink = selfLink);
-
-                // No magic here, just make download links to DownloadController.Download
-                feed.Channels.SelectMany(x => x.Items).ForEach(item =>
-                {
-                    var ext = Extensions[item.ContentType];
-                    item.DownloadLink = new Uri(selfHost, $"download/{feedId}/{item.Id}.{ext}");
-                });
-
-                serializedFeed = feed.ToString();
-
-                await _storageService.Cache(Constants.Cache.FeedsPrefix, feedId, serializedFeed, TimeSpan.FromMinutes(3));
+                var body = await _feedService.Get(feedId, FixLinks);
+                return Content(body, "application/rss+xml; charset=UTF-8");
             }
+            catch (KeyNotFoundException)
+            {
+                return NotFound($"ERROR: No feed with id {feedId}");
+            }
+        }
 
-            return Content(serializedFeed, "application/rss+xml; charset=UTF-8");
+        [NonAction]
+        private void FixLinks(string feedId, Feed feed)
+        {
+            var selfHost = Request.GetBaseUrl();
+
+            // Set atom link to this feed
+            // See https://validator.w3.org/feed/docs/warning/MissingAtomSelfLink.html
+            var selfLink = new Uri(selfHost, Request.Path);
+            feed.Channels.ForEach(x => x.AtomLink = selfLink);
+
+            // No magic here, just make download links to DownloadController.Download
+            feed.Channels.SelectMany(x => x.Items).ForEach(item =>
+            {
+                var ext = Extensions[item.ContentType];
+                item.DownloadLink = new Uri(selfHost, $"download/{feedId}/{item.Id}.{ext}");
+            });
         }
     }
 }
\ No newline at end of file
diff --git a/src/Podsync/Services/Rss/FeedService.cs b/src/Podsync/Services/Rss/FeedService.cs
index 7a58676..2e20b02 100644
--- a/src/Podsync/Services/Rss/FeedService.cs
+++ b/src/Podsync/Services/Rss/FeedService.cs
@@ -2,6 +2,7 @@
 using System.Threading.Tasks;
 using Podsync.Helpers;
 using Podsync.Services.Links;
+using Podsync.Services.Rss.Contracts;
 using Podsync.Services.Storage;
 
 namespace Podsync.Services.Rss
@@ -27,9 +28,28 @@ namespace Podsync.Services.Rss
             return _storageService.Save(metadata);
         }
 
-        public Task<Contracts.Feed> Get(string id)
+        public Task<Feed> Get(string id)
         {
             return _rssBuilder.Query(id);
         }
+
+        public async Task<string> Get(string id, Action<string, Feed> fixup)
+        {
+            var serializedFeed = await _storageService.GetCached(Constants.Cache.FeedsPrefix, id);
+
+            if (string.IsNullOrEmpty(serializedFeed))
+            {
+                var feed = await Get(id);
+
+                // Fix download links
+                fixup(id, feed);
+
+                // Add to cache
+                serializedFeed = feed.ToString();
+                await _storageService.Cache(Constants.Cache.FeedsPrefix, id, serializedFeed, TimeSpan.FromMinutes(3));
+            }
+
+            return serializedFeed;
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Podsync/Services/Rss/IFeedService.cs b/src/Podsync/Services/Rss/IFeedService.cs
index c7a013d..6132163 100644
--- a/src/Podsync/Services/Rss/IFeedService.cs
+++ b/src/Podsync/Services/Rss/IFeedService.cs
@@ -1,4 +1,6 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
+using Podsync.Services.Rss.Contracts;
 using Podsync.Services.Storage;
 
 namespace Podsync.Services.Rss
@@ -7,6 +9,8 @@ namespace Podsync.Services.Rss
     {
         Task<string> Create(FeedMetadata metadata);
 
-        Task<Contracts.Feed> Get(string id);
+        Task<Feed> Get(string id);
+
+        Task<string> Get(string id, Action<string, Feed> fixup);
     }
 }
\ No newline at end of file