Add fix for playlists with less than 100 videos

2 files changed, 79 insertions, 56 deletions

diff --git a/src/invidious.cr b/src/invidious.cr
index 6df2ee78..2e599864 100644
--- a/src/invidious.cr
+++ b/src/invidious.cr
@@ -390,13 +390,14 @@ get "/playlist" do |env|
   page = env.params.query["page"]?.try &.to_i?
   page ||= 1
 
+  playlist = fetch_playlist(plid)
+
   begin
-    videos = extract_playlist(plid, page)
+    videos = fetch_playlist_videos(plid, page, playlist.video_count)
   rescue ex
     error_message = ex.message
     next templated "error"
   end
-  playlist = fetch_playlist(plid)
 
   templated "playlist"
 end
@@ -470,11 +471,11 @@ get "/search" do |env|
   elsif subscriptions
     videos = PG_DB.query_all("SELECT id,title,published,updated,ucid,author FROM (
       SELECT *,
-        to_tsvector(channel_videos.title) ||
-        to_tsvector(channel_videos.author)
-          as document
+      to_tsvector(channel_videos.title) ||
+      to_tsvector(channel_videos.author)
+      as document
       FROM channel_videos WHERE ucid IN (#{arg_array(ucids, 3)})
-    ) v_search WHERE v_search.document @@ plainto_tsquery($1) LIMIT 20 OFFSET $2;", [search_query, (page - 1) * 20] + ucids, as: ChannelVideo)
+      ) v_search WHERE v_search.document @@ plainto_tsquery($1) LIMIT 20 OFFSET $2;", [search_query, (page - 1) * 20] + ucids, as: ChannelVideo)
     count = videos.size
   else
     begin
@@ -2822,15 +2823,15 @@ get "/api/v1/playlists/:plid" do |env|
   page = env.params.query["page"]?.try &.to_i?
   page ||= 1
 
+  playlist = fetch_playlist(plid)
+
   begin
-    videos = extract_playlist(plid, page)
+    videos = fetch_playlist_videos(plid, page, playlist.video_count)
   rescue ex
     error_message = {"error" => "Playlist is empty"}.to_json
     halt env, status_code: 404, response: error_message
   end
 
-  playlist = fetch_playlist(plid)
-
   response = JSON.build do |json|
     json.object do
       json.field "title", playlist.title
diff --git a/src/invidious/playlists.cr b/src/invidious/playlists.cr
index edfe6728..6afb7a79 100644
--- a/src/invidious/playlists.cr
+++ b/src/invidious/playlists.cr
@@ -25,58 +25,75 @@ class PlaylistVideo
   })
 end
 
-def extract_playlist(plid, page)
-  index = (page - 1) * 100
-  url = produce_playlist_url(plid, index)
-
+def fetch_playlist_videos(plid, page, video_count)
   client = make_client(YT_URL)
-  response = client.get(url)
-  response = JSON.parse(response.body)
-  if !response["content_html"]? || response["content_html"].as_s.empty?
-    raise "Playlist does not exist"
+
+  if video_count > 100
+    index = (page - 1) * 100
+    url = produce_playlist_url(plid, index)
+
+    response = client.get(url)
+    response = JSON.parse(response.body)
+    if !response["content_html"]? || response["content_html"].as_s.empty?
+      raise "Playlist is empty"
+    end
+
+    document = XML.parse_html(response["content_html"].as_s)
+    nodeset = document.xpath_nodes(%q(.//tr[contains(@class, "pl-video")]))
+    videos = extract_playlist(plid, nodeset, index)
+  else
+    if page > 1
+      videos = [] of PlaylistVideo
+    else
+      response = client.get("/playlist?list=#{plid}&disable_polymer=1")
+      document = XML.parse_html(response.body)
+      nodeset = document.xpath_nodes(%q(.//tr[contains(@class, "pl-video")]))
+
+      videos = extract_playlist(plid, nodeset, 0)
+    end
   end
 
+  return videos
+end
+
+def extract_playlist(plid, nodeset, index)
   videos = [] of PlaylistVideo
 
-  document = XML.parse_html(response["content_html"].as_s)
-  anchor = document.xpath_node(%q(//div[@class="pl-video-owner"]/a))
-  if anchor
-    document.xpath_nodes(%q(.//tr[contains(@class, "pl-video")])).each_with_index do |video, offset|
-      anchor = video.xpath_node(%q(.//td[@class="pl-video-title"]))
-      if !anchor
-        next
-      end
-
-      title = anchor.xpath_node(%q(.//a)).not_nil!.content.strip(" \n")
-      id = anchor.xpath_node(%q(.//a)).not_nil!["href"].lchop("/watch?v=")[0, 11]
-
-      anchor = anchor.xpath_node(%q(.//div[@class="pl-video-owner"]/a))
-      if anchor
-        author = anchor.content
-        ucid = anchor["href"].split("/")[2]
-      else
-        author = ""
-        ucid = ""
-      end
-
-      anchor = video.xpath_node(%q(.//td[@class="pl-video-time"]/div/div[1]))
-      if anchor && !anchor.content.empty?
-        length_seconds = decode_length_seconds(anchor.content)
-      else
-        length_seconds = 0
-      end
-
-      videos << PlaylistVideo.new(
-        title,
-        id,
-        author,
-        ucid,
-        length_seconds,
-        Time.now,
-        [plid],
-        index + offset,
-      )
+  nodeset.each_with_index do |video, offset|
+    anchor = video.xpath_node(%q(.//td[@class="pl-video-title"]))
+    if !anchor
+      next
     end
+
+    title = anchor.xpath_node(%q(.//a)).not_nil!.content.strip(" \n")
+    id = anchor.xpath_node(%q(.//a)).not_nil!["href"].lchop("/watch?v=")[0, 11]
+
+    anchor = anchor.xpath_node(%q(.//div[@class="pl-video-owner"]/a))
+    if anchor
+      author = anchor.content
+      ucid = anchor["href"].split("/")[2]
+    else
+      author = ""
+      ucid = ""
+    end
+
+    anchor = video.xpath_node(%q(.//td[@class="pl-video-time"]/div/div[1]))
+    if anchor && !anchor.content.empty?
+      length_seconds = decode_length_seconds(anchor.content)
+    else
+      length_seconds = 0
+    end
+
+    videos << PlaylistVideo.new(
+      title,
+      id,
+      author,
+      ucid,
+      length_seconds,
+      Time.now,
+      [plid],
+      index + offset,
+    )
   end
 
   return videos
@@ -112,13 +129,18 @@ def produce_playlist_url(id, index)
   continuation = Base64.urlsafe_encode(continuation)
   continuation = URI.escape(continuation)
 
-  url = "/browse_ajax?action_continuation=1&continuation=#{continuation}"
+  url = "/browse_ajax?continuation=#{continuation}"
 
   return url
 end
 
 def fetch_playlist(plid)
   client = make_client(YT_URL)
+
+  if plid.starts_with? "UC"
+    plid = "UU#{plid.lchop("UC")}"
+  end
+
   response = client.get("/playlist?list=#{plid}&disable_polymer=1")
   body = response.body.gsub(<<-END_BUTTON
   <button class="yt-uix-button yt-uix-button-size-default yt-uix-button-link yt-uix-expander-head playlist-description-expander yt-uix-inlineedit-ignore-edit" type="button" onclick=";return false;"><span class="yt-uix-button-content">  less <img alt="" src="/yts/img/pixel-vfl3z5WfW.gif">