Add support for 'user' URLs in NewPipe import

src/invidious.cr

@@ -1842,8 +1842,22 @@ post "/data_control" do |env|
         PG_DB.exec("UPDATE users SET subscriptions = $1 WHERE email = $2", user.subscriptions, user.email)
       when "import_newpipe_subscriptions"
         body = JSON.parse(body)
-        user.subscriptions += body["subscriptions"].as_a.map do |channel|
-          channel["url"].as_s.match(/UC[a-zA-Z0-9_-]{22}/).not_nil![0]
+        user.subscriptions += body["subscriptions"].as_a.compact_map do |channel|
+          if match = channel["url"].as_s.match(/\/channel\/(?<channel>UC[a-zA-Z0-9_-]{22})/)
+            next match["channel"]
+          elsif match = channel["url"].as_s.match(/\/user\/(?<user>.+)/)
+            client = make_client(YT_URL)
+            response = client.get("/user/#{match["user"]}?disable_polymer=1&hl=en&gl=US")
+            document = XML.parse_html(response.body)
+            canonical = document.xpath_node(%q(//link[@rel="canonical"]))
+
+            if canonical
+              ucid = canonical["href"].split("/")[-1]
+              next ucid
+            end
+          end
+
+          nil
         end
         user.subscriptions.uniq!
 

src/invidious/channels.cr

@@ -51,8 +51,7 @@ def get_batch_channels(channels, db, refresh = false, pull_all_videos = true, ma
 
   final = [] of String
   channels.size.times do
-    ucid = finished_channel.receive
-    if ucid
+    if ucid = finished_channel.receive
       final << ucid
     end
   end

src/invidious/search.cr

@@ -63,6 +63,12 @@ def channel_search(query, page, channel)
     canonical = document.xpath_node(%q(//link[@rel="canonical"]))
   end
 
+  if !canonical
+    response = client.get("/user/#{channel}?disable_polymer=1&hl=en&gl=US")
+    document = XML.parse_html(response.body)
+    canonical = document.xpath_node(%q(//link[@rel="canonical"]))
+  end
+
   if !canonical
     return 0, [] of SearchItem
   end