channel: use YT API + extractors to fetch videos

src/invidious/channels/channels.cr

@@ -180,11 +180,16 @@ def fetch_channel(ucid, pull_all_videos : Bool)
 
   LOGGER.trace("fetch_channel: #{ucid} : author = #{author}, auto_generated = #{auto_generated}")
 
-  page = 1
+  channel = InvidiousChannel.new({
+    id:         ucid,
+    author:     author,
+    updated:    Time.utc,
+    deleted:    false,
+    subscribed: nil,
+  })
 
   LOGGER.trace("fetch_channel: #{ucid} : Downloading channel videos page")
-  initial_data = get_channel_videos_response(ucid, page, auto_generated: auto_generated)
-  videos = extract_videos(initial_data, author, ucid)
+  videos, continuation = IV::Channel::Tabs.get_videos(channel)
 
   LOGGER.trace("fetch_channel: #{ucid} : Extracting videos from channel RSS feed")
   rss.xpath_nodes("//feed/entry").each do |entry|
@@ -197,7 +202,9 @@ def fetch_channel(ucid, pull_all_videos : Bool)
     views = entry.xpath_node("group/community/statistics").try &.["views"]?.try &.to_i64?
     views ||= 0_i64
 
-    channel_video = videos.select { |video| video.id == video_id }[0]?
+    channel_video = videos
+      .select(SearchVideo)
+      .select(&.id.== video_id)[0]?
 
     length_seconds = channel_video.try &.length_seconds
     length_seconds ||= 0
@@ -235,16 +242,14 @@ def fetch_channel(ucid, pull_all_videos : Bool)
   end
 
   if pull_all_videos
-    page += 1
-
-    ids = [] of String
-
     loop do
-      initial_data = get_channel_videos_response(ucid, page, auto_generated: auto_generated)
-      videos = extract_videos(initial_data, author, ucid)
+      # Keep fetching videos using the continuation token retrieved earlier
+      videos, continuation = IV::Channel::Tabs.get_videos(channel, continuation: continuation)
 
-      count = videos.size
-      videos = videos.map { |video| ChannelVideo.new({
+      count = 0
+      videos.select(SearchVideo).each do |video|
+        count += 1
+        video = ChannelVideo.new({
           id:                 video.id,
           title:              video.title,
           published:          video.published,
@@ -255,10 +260,7 @@ def fetch_channel(ucid, pull_all_videos : Bool)
           live_now:           video.live_now,
           premiere_timestamp: video.premiere_timestamp,
           views:              video.views,
-      }) }
-
-      videos.each do |video|
-        ids << video.id
+        })
 
         # We are notified of Red videos elsewhere (PubSub), which includes a correct published date,
         # so since they don't provide a published date here we can safely ignore them.
@@ -269,17 +271,10 @@ def fetch_channel(ucid, pull_all_videos : Bool)
       end
 
       break if count < 25
-      page += 1
+      sleep 500.milliseconds
     end
   end
 
-  channel = InvidiousChannel.new({
-    id:         ucid,
-    author:     author,
-    updated:    Time.utc,
-    deleted:    false,
-    subscribed: nil,
-  })
-
+  channel.updated = Time.utc
   return channel
 end

src/invidious/channels/playlists.cr

@@ -24,7 +24,7 @@ def fetch_channel_playlists(ucid, author, continuation, sort_by)
     initial_data = YoutubeAPI.browse(ucid, params: params || "")
   end
 
-  return extract_items(initial_data, ucid, author)
+  return extract_items(initial_data, author, ucid)
 end
 
 # ## NOTE: DEPRECATED

src/invidious/channels/videos.cr

@@ -16,6 +16,14 @@ def produce_channel_videos_continuation(ucid, page = 1, auto_generated = nil, so
     .try { |i| Base64.urlsafe_encode(i) }
     .try { |i| URI.encode_www_form(i) }
 
+  sort_by_numerical =
+    case sort_by
+    when "newest"  then 1_i64
+    when "popular" then 2_i64
+    when "oldest"  then 3_i64 # Broken as of 10/2022 :c
+    else                1_i64 # Fallback to "newest"
+    end
+
   object_inner_1 = {
     "110:embedded" => {
       "3:embedded" => {
@@ -24,7 +32,7 @@ def produce_channel_videos_continuation(ucid, page = 1, auto_generated = nil, so
             "1:string" => object_inner_2_encoded,
             "2:string" => "00000000-0000-0000-0000-000000000000",
           },
-          "3:varint" => 1_i64,
+          "3:varint" => sort_by_numerical,
         },
       },
     },
@@ -52,34 +60,66 @@ def produce_channel_videos_continuation(ucid, page = 1, auto_generated = nil, so
   return continuation
 end
 
-def get_channel_videos_response(ucid, page = 1, auto_generated = nil, sort_by = "newest")
-  continuation = produce_channel_videos_continuation(ucid, page,
-    auto_generated: auto_generated, sort_by: sort_by, v2: true)
-
-  return YoutubeAPI.browse(continuation)
-end
-
-def get_60_videos(ucid, author, page, auto_generated, sort_by = "newest")
-  videos = [] of SearchVideo
-
-  # 2.times do |i|
-  # initial_data = get_channel_videos_response(ucid, page * 2 + (i - 1), auto_generated: auto_generated, sort_by: sort_by)
-  initial_data = get_channel_videos_response(ucid, 1, auto_generated: auto_generated, sort_by: sort_by)
-  videos = extract_videos(initial_data, author, ucid)
-  # end
-
-  return videos.size, videos
-end
-
-def get_latest_videos(ucid)
-  initial_data = get_channel_videos_response(ucid)
-  author = initial_data["metadata"]?.try &.["channelMetadataRenderer"]?.try &.["title"]?.try &.as_s
-
-  return extract_videos(initial_data, author, ucid)
-end
-
 # Used in bypass_captcha_job.cr
 def produce_channel_videos_url(ucid, page = 1, auto_generated = nil, sort_by = "newest", v2 = false)
   continuation = produce_channel_videos_continuation(ucid, page, auto_generated, sort_by, v2)
   return "/browse_ajax?continuation=#{continuation}&gl=US&hl=en"
 end
+
+module Invidious::Channel::Tabs
+  extend self
+
+  # -------------------
+  #  Regular videos
+  # -------------------
+
+  def make_initial_video_ctoken(ucid, sort_by) : String
+    return produce_channel_videos_continuation(ucid, sort_by: sort_by)
+  end
+
+  # Wrapper for AboutChannel, as we still need to call get_videos with
+  # an author name and ucid directly (e.g in RSS feeds).
+  # TODO: figure out how to get rid of that
+  def get_videos(channel : AboutChannel, *, continuation : String? = nil, sort_by = "newest")
+    return get_videos(
+      channel.author, channel.ucid,
+      continuation: continuation, sort_by: sort_by
+    )
+  end
+
+  # Wrapper for InvidiousChannel, as we still need to call get_videos with
+  # an author name and ucid directly (e.g in RSS feeds).
+  # TODO: figure out how to get rid of that
+  def get_videos(channel : InvidiousChannel, *, continuation : String? = nil, sort_by = "newest")
+    return get_videos(
+      channel.author, channel.id,
+      continuation: continuation, sort_by: sort_by
+    )
+  end
+
+  def get_videos(author : String, ucid : String, *, continuation : String? = nil, sort_by = "newest")
+    continuation ||= make_initial_video_ctoken(ucid, sort_by)
+    initial_data = YoutubeAPI.browse(continuation: continuation)
+
+    return extract_items(initial_data, author, ucid)
+  end
+
+  def get_60_videos(channel : AboutChannel, *, continuation : String? = nil, sort_by = "newest")
+    if continuation.nil?
+      # Fetch the first "page" of video
+      items, next_continuation = get_videos(channel, sort_by: sort_by)
+    else
+      # Fetch a "page" of videos using the given continuation token
+      items, next_continuation = get_videos(channel, continuation: continuation)
+    end
+
+    # If there is more to load, then load a second "page"
+    # and replace the previous continuation token
+    if !next_continuation.nil?
+      items_2, next_continuation = get_videos(channel, continuation: next_continuation)
+      items.concat items_2
+    end
+
+    return items, next_continuation
+  end
+end

src/invidious/routes/api/v1/channels.cr

@@ -5,8 +5,6 @@ module Invidious::Routes::API::V1::Channels
     env.response.content_type = "application/json"
 
     ucid = env.params.url["ucid"]
-    sort_by = env.params.query["sort_by"]?.try &.downcase
-    sort_by ||= "newest"
 
     begin
       channel = get_about_info(ucid, locale)
@@ -19,17 +17,14 @@ module Invidious::Routes::API::V1::Channels
       return error_json(500, ex)
     end
 
-    page = 1
-    if channel.auto_generated
-      videos = [] of SearchVideo
-      count = 0
-    else
+    # Retrieve "sort by" setting from URL parameters
+    sort_by = env.params.query["sort_by"]?.try &.downcase || "newest"
+
     begin
-        count, videos = get_60_videos(channel.ucid, channel.author, page, channel.auto_generated, sort_by)
+      videos, _ = Channel::Tabs.get_videos(channel, sort_by: sort_by)
     rescue ex
       return error_json(500, ex)
     end
-    end
 
     JSON.build do |json|
       # TODO: Refactor into `to_json` for InvidiousChannel
@@ -134,25 +129,11 @@ module Invidious::Routes::API::V1::Channels
   end
 
   def self.latest(env)
-    locale = env.get("preferences").as(Preferences).locale
+    # Remove parameters that could affect this endpoint's behavior
+    env.params.query.delete("sort_by") if env.params.query.has_key?("sort_by")
+    env.params.query.delete("continuation") if env.params.query.has_key?("continuation")
 
-    env.response.content_type = "application/json"
-
-    ucid = env.params.url["ucid"]
-
-    begin
-      videos = get_latest_videos(ucid)
-    rescue ex
-      return error_json(500, ex)
-    end
-
-    JSON.build do |json|
-      json.array do
-        videos.each do |video|
-          video.to_json(locale, json)
-        end
-      end
-    end
+    return self.videos(env)
   end
 
   def self.videos(env)
@@ -161,11 +142,6 @@ module Invidious::Routes::API::V1::Channels
     env.response.content_type = "application/json"
 
     ucid = env.params.url["ucid"]
-    page = env.params.query["page"]?.try &.to_i?
-    page ||= 1
-    sort_by = env.params.query["sort"]?.try &.downcase
-    sort_by ||= env.params.query["sort_by"]?.try &.downcase
-    sort_by ||= "newest"
 
     begin
       channel = get_about_info(ucid, locale)
@@ -178,18 +154,28 @@ module Invidious::Routes::API::V1::Channels
       return error_json(500, ex)
     end
 
+    # Retrieve some URL parameters
+    sort_by = env.params.query["sort_by"]?.try &.downcase || "newest"
+    continuation = env.params.query["continuation"]?
+
     begin
-      count, videos = get_60_videos(channel.ucid, channel.author, page, channel.auto_generated, sort_by)
+      videos, next_continuation = Channel::Tabs.get_60_videos(
+        channel, continuation: continuation, sort_by: sort_by
+      )
     rescue ex
       return error_json(500, ex)
     end
 
-    JSON.build do |json|
+    return JSON.build do |json|
+      json.object do
+        json.field "videos" do
           json.array do
-        videos.each do |video|
-          video.to_json(locale, json)
+            videos.each &.to_json(locale, json)
           end
         end
+
+        json.field "continuation", next_continuation if next_continuation
+      end
     end
   end
 

src/invidious/routes/channels.cr

@@ -32,7 +32,9 @@ module Invidious::Routes::Channels
       sort_options = {"newest", "oldest", "popular"}
       sort_by ||= "newest"
 
-      count, items = get_60_videos(channel.ucid, channel.author, 1, channel.auto_generated, sort_by)
+      items, continuation = Channel::Tabs.get_60_videos(
+        channel, continuation: continuation, sort_by: sort_by
+      )
     end
 
     templated "channel"