From ebe51c91d762a3e9c4804fe04ee81b81da64967b Mon Sep 17 00:00:00 2001
From: Omar Roth <omarroth@hotmail.com>
Date: Tue, 6 Mar 2018 22:00:35 -0600
Subject: [PATCH] Add local alternatives for video links

---
 src/helpers.cr      | 48 +++++++++++++++++++++++++++++++++++++++++++++
 src/invidious.cr    |  8 +++++++-
 src/views/watch.ecr |  4 ++--
 3 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/src/helpers.cr b/src/helpers.cr
index 2d2b9337..fae9653e 100644
--- a/src/helpers.cr
+++ b/src/helpers.cr
@@ -290,6 +290,9 @@ def template_comments(root)
       score = child["data"]["score"]
       body_html = HTML.unescape(child["data"]["body_html"].as_s)
 
+      # Replace local links wtih links back to Reddit
+      body_html = fill_links(body_html, "https", "www.reddit.com")
+
       replies_html = ""
       if child["data"]["replies"] != ""
         replies_html = template_comments(child["data"]["replies"]["data"]["children"])
@@ -341,3 +344,48 @@ def arg_array(array)
 
   return args
 end
+
+def add_alt_links(html)
+  alt_links = [] of {Int32, String}
+
+  # This is painful but is likely the only way to accomplish this in Crystal,
+  # as Crystigiri and others are not able to insert XML Nodes into a document.
+  # The goal here is to use as little regex as possible
+  html.scan(/<a[^>]*>([^<]+)<\/a>/) do |match|
+    anchor = XML.parse_html(match[0])
+    anchor = anchor.xpath_node("//a").not_nil!
+    url = URI.parse(HTML.unescape(anchor["href"]))
+
+    if ["www.youtube.com", "youtu.be", "m.youtube.com"].includes?(url.host) && url.path == "/watch"
+      alt_link = <<-END_HTML
+      <a class="link" href="#{url.full_path}">
+        <i class="fa fa-link" aria-hidden="true"></i>
+      </a>
+      END_HTML
+
+      alt_links << {match.end.not_nil!, alt_link}
+    end
+  end
+
+  alt_links.reverse!
+  alt_links.each do |position, alt_link|
+    html = html.insert(position, alt_link)
+  end
+
+  return html
+end
+
+def fill_links(html, scheme, host)
+  html = XML.parse_html(html)
+
+  html.xpath_nodes("//a").each do |match|
+    url = URI.parse(match["href"])
+    if !url.host # If reddit link
+      url.scheme = scheme
+      url.host = host
+      match["href"] = url
+    end
+  end
+
+  html = html.to_xml
+end
diff --git a/src/invidious.cr b/src/invidious.cr
index 9758349c..4b3cdd64 100644
--- a/src/invidious.cr
+++ b/src/invidious.cr
@@ -218,11 +218,17 @@ get "/watch" do |env|
   headers = HTTP::Headers{"User-Agent" => "web:invidio.us:v0.1.0 (by /u/omarroth)"}
   begin
     reddit_comments, reddit_thread = get_reddit_comments(id, reddit_client, headers)
+    reddit_html = template_comments(reddit_comments)
+
+    reddit_html = add_alt_links(reddit_html)
   rescue ex
-    reddit_comments = JSON.parse("[]")
     reddit_thread = nil
+    reddit_html = ""
   end
 
+  video.description = fill_links(video.description, "https", "www.youtube.com")
+  video.description = add_alt_links(video.description)
+
   templated "watch"
 end
 
diff --git a/src/views/watch.ecr b/src/views/watch.ecr
index 18307e83..a9600320 100644
--- a/src/views/watch.ecr
+++ b/src/views/watch.ecr
@@ -105,13 +105,13 @@ function toggle(target) {
             <%= video.description %>
         </div>
         <hr style="margin-right:1em;">
-        <% if reddit_thread  && !reddit_comments.as_a.empty? %>
+        <% if reddit_thread  && !reddit_html.empty? %>
         <div style="margin-right:1em; overflow-wrap:break-word; word-wrap:break-word;">
             <h3><%= reddit_thread.data.title %></h3>
             <b>
                 <a target="_blank" class="link" href="https://reddit.com<%= reddit_thread.data.permalink %>">View comments on Reddit</a>
             </b>
-            <%= template_comments(reddit_comments) %>
+            <%= reddit_html %>
         </div>
         <% end %>
     </div>