Add support for channel redirects

src/invidious/channels.cr

@@ -127,6 +127,13 @@ struct AboutChannel
   })
 end
 
+class ChannelRedirect < Exception
+  property channel_id : String
+
+  def initialize(@channel_id)
+  end
+end
+
 def get_batch_channels(channels, db, refresh = false, pull_all_videos = true, max_threads = 10)
   finished_channel = Channel(String | Nil).new
 
@@ -927,6 +934,10 @@ def get_about_info(ucid, locale)
     about = client.get("/user/#{ucid}/about?disable_polymer=1&gl=US&hl=en")
   end
 
+  if md = about.headers["location"]?.try &.match(/\/channel\/(?<ucid>UC[a-zA-Z0-9_-]{22})/)
+    raise ChannelRedirect.new(channel_id: md["ucid"])
+  end
+
   about = XML.parse_html(about.body)
 
   if about.xpath_node(%q(//div[contains(@class, "channel-empty-message")]))

src/invidious/videos.cr

@@ -882,6 +882,10 @@ struct CaptionName
 end
 
 class VideoRedirect < Exception
+  property video_id : String
+
+  def initialize(@video_id)
+  end
 end
 
 def get_video(id, db, refresh = true, region = nil, force_refresh = false)
@@ -1149,7 +1153,7 @@ def fetch_video(id, region)
   response = client.get("/watch?v=#{id}&gl=US&hl=en&disable_polymer=1&has_verified=1&bpctr=9999999999")
 
   if md = response.headers["location"]?.try &.match(/v=(?<id>[a-zA-Z0-9_-]{11})/)
-    raise VideoRedirect.new(md["id"])
+    raise VideoRedirect.new(video_id: md["id"])
   end
 
   html = XML.parse_html(response.body)