From eaa463f2c08c8e5fe73a1d6a6f53f51578a089ad Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Sat, 9 Mar 2019 10:59:08 -0500
Subject: [PATCH] Make parsing articles more resilient

---
 lib/frenzy/update_feeds.ex | 69 +++++++++++++++++++++++++++-----------
 1 file changed, 49 insertions(+), 20 deletions(-)

diff --git a/lib/frenzy/update_feeds.ex b/lib/frenzy/update_feeds.ex
index deb3b28..91d3049 100644
--- a/lib/frenzy/update_feeds.ex
+++ b/lib/frenzy/update_feeds.ex
@@ -31,7 +31,8 @@ defmodule Frenzy.UpdateFeeds do
   end
 
   defp schedule_update() do
-    Process.send_after(self(), :update_feeds, 15 * 60 * 1000) # 15 minutes
+    # 15 minutes
+    Process.send_after(self(), :update_feeds, 15 * 60 * 1000)
     # Process.send_after(self(), :update_feeds, 60 * 1000) # 1 minutes
   end
 
@@ -43,7 +44,9 @@ defmodule Frenzy.UpdateFeeds do
   end
 
   defp prune_old_items() do
-    {count, _} = Repo.delete_all(from i in Item, where: i.read, where: i.read_date <= from_now(-1, "week"))
+    {count, _} =
+      Repo.delete_all(from i in Item, where: i.read, where: i.read_date <= from_now(-1, "week"))
+
     Logger.info("Removed #{count} read items")
   end
 
@@ -56,19 +59,23 @@ defmodule Frenzy.UpdateFeeds do
           {:ok, rss} ->
             update_feed_from_rss(feed, rss)
         end
+
       {:ok, %HTTPoison.Response{status_code: 404}} ->
         Logger.warn("RSS feed #{feed.feed_url} not found")
+
       {:error, %HTTPoison.Error{reason: reason}} ->
         Logger.error("Couldn't load RSS feed: #{reason}")
     end
   end
 
   defp update_feed_from_rss(feed, rss) do
-    changeset = Feed.changeset(feed, %{
-      title: rss.title,
-      site_url: rss.link.href,
-      last_updated: parse_date(rss.updated_at)
+    changeset =
+      Feed.changeset(feed, %{
+        title: rss.title,
+        site_url: rss.link.href,
+        last_updated: parse_date(rss.updated_at)
       })
+
     Repo.update(changeset)
 
     feed = Repo.preload(feed, :items)
@@ -86,22 +93,30 @@ defmodule Frenzy.UpdateFeeds do
 
     url = get_real_url(entry)
 
-    changeset = Ecto.build_assoc(feed, :items, %{
-      guid: entry.id,
-      title: entry.title,
-      url: url,
-      date: parse_date(entry.published_at),
-      creator: "",
-      content: get_article_content(url)
-      })
+    case get_article_content(url) do
+      {:ok, content} ->
+        changeset =
+          Ecto.build_assoc(feed, :items, %{
+            guid: entry.id,
+            title: entry.title,
+            url: url,
+            date: parse_date(entry.published_at),
+            creator: "",
+            content: content
+          })
 
-    Repo.insert(changeset)
+        Repo.insert(changeset)
+
+      {:err, reason} ->
+        Logger.error("Unable to create item for #{url}: #{reason}")
+    end
   end
 
   defp parse_date(str) do
     case Timex.parse(str, "{RFC1123}") do
       {:ok, date} ->
         Timex.Timezone.convert(date, :utc)
+
       _ ->
         {:ok, date, _} = DateTime.from_iso8601(str)
         Timex.Timezone.convert(date, :utc)
@@ -110,13 +125,16 @@ defmodule Frenzy.UpdateFeeds do
 
   defp get_real_url(entry) do
     links = Enum.reject(entry.links, fn l -> l.rel == "shorturl" end)
+
     case Enum.find(links, fn l -> l.rel == "related" end) do
       nil ->
         case Enum.find(links, fn l -> l.rel == "alternate" end) do
           nil -> Enum.fetch!(links, 0).href
           link -> link.href
         end
-      link -> link.href
+
+      link ->
+        link.href
     end
   end
 
@@ -126,11 +144,22 @@ defmodule Frenzy.UpdateFeeds do
     case HTTPoison.get(url) do
       {:ok, %HTTPoison.Response{status_code: 200, body: body}} ->
         article = Readability.article(body)
-        Readability.readable_html(article)
+        {:ok, Readability.readable_html(article)}
+
       {:ok, %HTTPoison.Response{status_code: 404}} ->
-        Logger.warn("Article #{url} not found")
+        {:err, "404 not found"}
+
+      {:ok, %HTTPoison.Response{status_code: 301, headers: headers}} ->
+        {"Location", new_url} =
+          Enum.find(headers, fn {name, value} ->
+            name == "Location"
+          end)
+
+        Logger.debug("Got 301 redirect from #{url} to #{new_url}")
+        get_article_content(new_url)
+
       {:error, %HTTPoison.Error{reason: reason}} ->
-        Logger.error("Couldn't load article: #{reason}")
+        {:err, reason}
     end
   end
-end
\ No newline at end of file
+end