Use new youtube API to fetch channel videos (#1355)

* Use new API to fetch videos from channels

This mirrors the process used by subscriptions.gir.st. The old API is
tried first, and if it fails then the new one is used.

* Use the new API whenever getting videos from a channel

I created the get_channel_videos_response function because now instead
of just getting a single url, there are extra steps involved in getting
the API response for channel videos, and these steps don't need to be
repeated throughout the code.

The only remaining exception is the bypass_captcha function, which still
only makes a request to the old API. I don't know whether this code
needs to be updated to use the new API for captcha bypassing to work
correctly.

* Correctly determine video length with new api

* Remove unnecessary line

2 files changed, 205 insertions, 157 deletions

diff --git a/src/invidious/channels.cr b/src/invidious/channels.cr
index da062755..007aa06c 100644
--- a/src/invidious/channels.cr
+++ b/src/invidious/channels.cr
@@ -213,8 +213,7 @@ def fetch_channel(ucid, db, pull_all_videos = true, locale = nil)
 
   page = 1
 
-  url = produce_channel_videos_url(ucid, page, auto_generated: auto_generated)
-  response = YT_POOL.client &.get(url)
+  response = get_channel_videos_response(ucid, page, auto_generated: auto_generated)
 
   videos = [] of SearchVideo
   begin
@@ -291,8 +290,7 @@ def fetch_channel(ucid, db, pull_all_videos = true, locale = nil)
     ids = [] of String
 
     loop do
-      url = produce_channel_videos_url(ucid, page, auto_generated: auto_generated)
-      response = YT_POOL.client &.get(url)
+      response = get_channel_videos_response(ucid, page, auto_generated: auto_generated)
       initial_data = JSON.parse(response.body).as_a.find &.["response"]?
       raise "Could not extract JSON" if !initial_data
       videos = extract_videos(initial_data.as_h, author, ucid)
@@ -396,7 +394,7 @@ def fetch_channel_playlists(ucid, author, auto_generated, continuation, sort_by)
   return items, continuation
 end
 
-def produce_channel_videos_url(ucid, page = 1, auto_generated = nil, sort_by = "newest")
+def produce_channel_videos_url(ucid, page = 1, auto_generated = nil, sort_by = "newest", v2 = false)
   object = {
     "80226972:embedded" => {
       "2:string" => ucid,
@@ -411,18 +409,33 @@ def produce_channel_videos_url(ucid, page = 1, auto_generated = nil, sort_by = "
     },
   }
 
-  if auto_generated
-    seed = Time.unix(1525757349)
-    until seed >= Time.utc
-      seed += 1.month
-    end
-    timestamp = seed - (page - 1).months
+  if !v2
+    if auto_generated
+      seed = Time.unix(1525757349)
+      until seed >= Time.utc
+        seed += 1.month
+      end
+      timestamp = seed - (page - 1).months
 
-    object["80226972:embedded"]["3:base64"].as(Hash)["4:varint"] = 0x36_i64
-    object["80226972:embedded"]["3:base64"].as(Hash)["15:string"] = "#{timestamp.to_unix}"
+      object["80226972:embedded"]["3:base64"].as(Hash)["4:varint"] = 0x36_i64
+      object["80226972:embedded"]["3:base64"].as(Hash)["15:string"] = "#{timestamp.to_unix}"
+    else
+      object["80226972:embedded"]["3:base64"].as(Hash)["4:varint"] = 0_i64
+      object["80226972:embedded"]["3:base64"].as(Hash)["15:string"] = "#{page}"
+    end
   else
     object["80226972:embedded"]["3:base64"].as(Hash)["4:varint"] = 0_i64
-    object["80226972:embedded"]["3:base64"].as(Hash)["15:string"] = "#{page}"
+
+    object["80226972:embedded"]["3:base64"].as(Hash)["61:string"] = Base64.urlsafe_encode(Protodec::Any.from_json(Protodec::Any.cast_json({
+      "1:embedded" => {
+        "1:varint" => 6307666885028338688_i64,
+        "2:embedded" => {
+          "1:string" => Base64.urlsafe_encode(Protodec::Any.from_json(Protodec::Any.cast_json({
+            "1:varint" => 30_i64 * (page - 1),
+          }))),
+        },
+      },
+    })))
   end
 
   case sort_by
@@ -901,12 +914,28 @@ def get_about_info(ucid, locale)
   })
 end
 
+def get_channel_videos_response(ucid, page = 1, auto_generated = nil, sort_by = "newest")
+  url = produce_channel_videos_url(ucid, page, auto_generated: auto_generated, sort_by: sort_by, v2: false)
+  response = YT_POOL.client &.get(url)
+  initial_data = JSON.parse(response.body).as_a.find &.["response"]?
+  return response if !initial_data
+  needs_v2 = initial_data
+    .try &.["response"]?.try &.["alerts"]?
+    .try &.as_a.any? { |alert|
+      alert.try &.["alertRenderer"]?.try &.["type"]?.try { |t| t == "ERROR" }
+    }
+  if needs_v2
+    url = produce_channel_videos_url(ucid, page, auto_generated: auto_generated, sort_by: sort_by, v2: true)
+    response = YT_POOL.client &.get(url)
+  end
+  response
+end
+
 def get_60_videos(ucid, author, page, auto_generated, sort_by = "newest")
   videos = [] of SearchVideo
 
   2.times do |i|
-    url = produce_channel_videos_url(ucid, page * 2 + (i - 1), auto_generated: auto_generated, sort_by: sort_by)
-    response = YT_POOL.client &.get(url)
+    response = get_channel_videos_response(ucid, page * 2 + (i - 1), auto_generated: auto_generated, sort_by: sort_by)
     initial_data = JSON.parse(response.body).as_a.find &.["response"]?
     break if !initial_data
     videos.concat extract_videos(initial_data.as_h, author, ucid)
@@ -916,8 +945,7 @@ def get_60_videos(ucid, author, page, auto_generated, sort_by = "newest")
 end
 
 def get_latest_videos(ucid)
-  url = produce_channel_videos_url(ucid, 0)
-  response = YT_POOL.client &.get(url)
+  response = get_channel_videos_response(ucid, 1)
   initial_data = JSON.parse(response.body).as_a.find &.["response"]?
   return [] of SearchVideo if !initial_data
   author = initial_data["response"]?.try &.["metadata"]?.try &.["channelMetadataRenderer"]?.try &.["title"]?.try &.as_s
diff --git a/src/invidious/helpers/helpers.cr b/src/invidious/helpers/helpers.cr
index 56f856c0..6571f818 100644
--- a/src/invidious/helpers/helpers.cr
+++ b/src/invidious/helpers/helpers.cr
@@ -164,148 +164,168 @@ def extract_videos(initial_data : Hash(String, JSON::Any), author_fallback : Str
   extract_items(initial_data, author_fallback, author_id_fallback).select(&.is_a?(SearchVideo)).map(&.as(SearchVideo))
 end
 
+def extract_item(item : JSON::Any, author_fallback : String? = nil, author_id_fallback : String? = nil)
+  if i = (item["videoRenderer"]? || item["gridVideoRenderer"]?)
+    video_id = i["videoId"].as_s
+    title = i["title"].try { |t| t["simpleText"]?.try &.as_s || t["runs"]?.try &.as_a.map(&.["text"].as_s).join("") } || ""
+
+    author_info = i["ownerText"]?.try &.["runs"].as_a[0]?
+    author = author_info.try &.["text"].as_s || author_fallback || ""
+    author_id = author_info.try &.["navigationEndpoint"]?.try &.["browseEndpoint"]["browseId"].as_s || author_id_fallback || ""
+
+    published = i["publishedTimeText"]?.try &.["simpleText"]?.try { |t| decode_date(t.as_s) } || Time.local
+    view_count = i["viewCountText"]?.try &.["simpleText"]?.try &.as_s.gsub(/\D+/, "").to_i64? || 0_i64
+    description_html = i["descriptionSnippet"]?.try { |t| parse_content(t) } || ""
+    length_seconds = i["lengthText"]?.try &.["simpleText"]?.try &.as_s.try { |t| decode_length_seconds(t) } ||
+      i["thumbnailOverlays"]?.try &.as_a.find(&.["thumbnailOverlayTimeStatusRenderer"]?).try &.["thumbnailOverlayTimeStatusRenderer"]?
+        .try &.["text"]?.try &.["simpleText"]?.try &.as_s.try { |t| decode_length_seconds(t) } || 0
+
+    live_now = false
+    paid = false
+    premium = false
+
+    premiere_timestamp = i["upcomingEventData"]?.try &.["startTime"]?.try { |t| Time.unix(t.as_s.to_i64) }
+
+    i["badges"]?.try &.as_a.each do |badge|
+      b = badge["metadataBadgeRenderer"]
+      case b["label"].as_s
+      when "LIVE NOW"
+        live_now = true
+      when "New", "4K", "CC"
+        # TODO
+      when "Premium"
+        paid = true
+
+        # TODO: Potentially available as i["topStandaloneBadge"]["metadataBadgeRenderer"]
+        premium = true
+      else nil # Ignore
+      end
+    end
+
+    SearchVideo.new({
+      title:              title,
+      id:                 video_id,
+      author:             author,
+      ucid:               author_id,
+      published:          published,
+      views:              view_count,
+      description_html:   description_html,
+      length_seconds:     length_seconds,
+      live_now:           live_now,
+      paid:               paid,
+      premium:            premium,
+      premiere_timestamp: premiere_timestamp,
+    })
+  elsif i = item["channelRenderer"]?
+    author = i["title"]["simpleText"]?.try &.as_s || author_fallback || ""
+    author_id = i["channelId"]?.try &.as_s || author_id_fallback || ""
+
+    author_thumbnail = i["thumbnail"]["thumbnails"]?.try &.as_a[0]?.try { |u| "https:#{u["url"]}" } || ""
+    subscriber_count = i["subscriberCountText"]?.try &.["simpleText"]?.try &.as_s.try { |s| short_text_to_number(s.split(" ")[0]) } || 0
+
+    auto_generated = false
+    auto_generated = true if !i["videoCountText"]?
+    video_count = i["videoCountText"]?.try &.["runs"].as_a[0]?.try &.["text"].as_s.gsub(/\D/, "").to_i || 0
+    description_html = i["descriptionSnippet"]?.try { |t| parse_content(t) } || ""
+
+    SearchChannel.new({
+      author:           author,
+      ucid:             author_id,
+      author_thumbnail: author_thumbnail,
+      subscriber_count: subscriber_count,
+      video_count:      video_count,
+      description_html: description_html,
+      auto_generated:   auto_generated,
+    })
+  elsif i = item["gridPlaylistRenderer"]?
+    title = i["title"]["runs"].as_a[0]?.try &.["text"].as_s || ""
+    plid = i["playlistId"]?.try &.as_s || ""
+
+    video_count = i["videoCountText"]["runs"].as_a[0]?.try &.["text"].as_s.gsub(/\D/, "").to_i || 0
+    playlist_thumbnail = i["thumbnail"]["thumbnails"][0]?.try &.["url"]?.try &.as_s || ""
+
+    SearchPlaylist.new({
+      title:       title,
+      id:          plid,
+      author:      author_fallback || "",
+      ucid:        author_id_fallback || "",
+      video_count: video_count,
+      videos:      [] of SearchPlaylistVideo,
+      thumbnail:   playlist_thumbnail,
+    })
+  elsif i = item["playlistRenderer"]?
+    title = i["title"]["simpleText"]?.try &.as_s || ""
+    plid = i["playlistId"]?.try &.as_s || ""
+
+    video_count = i["videoCount"]?.try &.as_s.to_i || 0
+    playlist_thumbnail = i["thumbnails"].as_a[0]?.try &.["thumbnails"]?.try &.as_a[0]?.try &.["url"].as_s || ""
+
+    author_info = i["shortBylineText"]?.try &.["runs"].as_a[0]?
+    author = author_info.try &.["text"].as_s || author_fallback || ""
+    author_id = author_info.try &.["navigationEndpoint"]?.try &.["browseEndpoint"]["browseId"].as_s || author_id_fallback || ""
+
+    videos = i["videos"]?.try &.as_a.map do |v|
+      v = v["childVideoRenderer"]
+      v_title = v["title"]["simpleText"]?.try &.as_s || ""
+      v_id = v["videoId"]?.try &.as_s || ""
+      v_length_seconds = v["lengthText"]?.try &.["simpleText"]?.try { |t| decode_length_seconds(t.as_s) } || 0
+      SearchPlaylistVideo.new({
+        title:          v_title,
+        id:             v_id,
+        length_seconds: v_length_seconds,
+      })
+    end || [] of SearchPlaylistVideo
+
+    # TODO: i["publishedTimeText"]?
+
+    SearchPlaylist.new({
+      title:       title,
+      id:          plid,
+      author:      author,
+      ucid:        author_id,
+      video_count: video_count,
+      videos:      videos,
+      thumbnail:   playlist_thumbnail,
+    })
+  elsif i = item["radioRenderer"]? # Mix
+    # TODO
+  elsif i = item["showRenderer"]? # Show
+    # TODO
+  elsif i = item["shelfRenderer"]?
+  elsif i = item["horizontalCardListRenderer"]?
+  elsif i = item["searchPyvRenderer"]? # Ad
+  end
+end
+
 def extract_items(initial_data : Hash(String, JSON::Any), author_fallback : String? = nil, author_id_fallback : String? = nil)
   items = [] of SearchItem
 
-  initial_data.try { |t| t["contents"]? || t["response"]? }
-    .try { |t| t["twoColumnBrowseResultsRenderer"]?.try &.["tabs"].as_a.select(&.["tabRenderer"]?.try &.["selected"].as_bool)[0]?.try &.["tabRenderer"]["content"] ||
-      t["twoColumnSearchResultsRenderer"]?.try &.["primaryContents"] ||
-      t["continuationContents"]? }
-    .try { |t| t["sectionListRenderer"]? || t["sectionListContinuation"]? }
-    .try &.["contents"].as_a
-      .each { |c| c.try &.["itemSectionRenderer"]?.try &.["contents"].as_a
-        .try { |t| t[0]?.try &.["shelfRenderer"]?.try &.["content"]["expandedShelfContentsRenderer"]?.try &.["items"].as_a ||
-          t[0]?.try &.["gridRenderer"]?.try &.["items"].as_a || t }
-        .each { |item|
-          if i = item["videoRenderer"]?
-            video_id = i["videoId"].as_s
-            title = i["title"].try { |t| t["simpleText"]?.try &.as_s || t["runs"]?.try &.as_a.map(&.["text"].as_s).join("") } || ""
-
-            author_info = i["ownerText"]?.try &.["runs"].as_a[0]?
-            author = author_info.try &.["text"].as_s || author_fallback || ""
-            author_id = author_info.try &.["navigationEndpoint"]?.try &.["browseEndpoint"]["browseId"].as_s || author_id_fallback || ""
-
-            published = i["publishedTimeText"]?.try &.["simpleText"]?.try { |t| decode_date(t.as_s) } || Time.local
-            view_count = i["viewCountText"]?.try &.["simpleText"]?.try &.as_s.gsub(/\D+/, "").to_i64? || 0_i64
-            description_html = i["descriptionSnippet"]?.try { |t| parse_content(t) } || ""
-            length_seconds = i["lengthText"]?.try &.["simpleText"]?.try &.as_s.try { |t| decode_length_seconds(t) } || 0
-
-            live_now = false
-            paid = false
-            premium = false
-
-            premiere_timestamp = i["upcomingEventData"]?.try &.["startTime"]?.try { |t| Time.unix(t.as_s.to_i64) }
-
-            i["badges"]?.try &.as_a.each do |badge|
-              b = badge["metadataBadgeRenderer"]
-              case b["label"].as_s
-              when "LIVE NOW"
-                live_now = true
-              when "New", "4K", "CC"
-                # TODO
-              when "Premium"
-                paid = true
-
-                # TODO: Potentially available as i["topStandaloneBadge"]["metadataBadgeRenderer"]
-                premium = true
-              else nil # Ignore
-              end
-            end
-
-            items << SearchVideo.new({
-              title:              title,
-              id:                 video_id,
-              author:             author,
-              ucid:               author_id,
-              published:          published,
-              views:              view_count,
-              description_html:   description_html,
-              length_seconds:     length_seconds,
-              live_now:           live_now,
-              paid:               paid,
-              premium:            premium,
-              premiere_timestamp: premiere_timestamp,
-            })
-          elsif i = item["channelRenderer"]?
-            author = i["title"]["simpleText"]?.try &.as_s || author_fallback || ""
-            author_id = i["channelId"]?.try &.as_s || author_id_fallback || ""
-
-            author_thumbnail = i["thumbnail"]["thumbnails"]?.try &.as_a[0]?.try { |u| "https:#{u["url"]}" } || ""
-            subscriber_count = i["subscriberCountText"]?.try &.["simpleText"]?.try &.as_s.try { |s| short_text_to_number(s.split(" ")[0]) } || 0
-
-            auto_generated = false
-            auto_generated = true if !i["videoCountText"]?
-            video_count = i["videoCountText"]?.try &.["runs"].as_a[0]?.try &.["text"].as_s.gsub(/\D/, "").to_i || 0
-            description_html = i["descriptionSnippet"]?.try { |t| parse_content(t) } || ""
-
-            items << SearchChannel.new({
-              author:           author,
-              ucid:             author_id,
-              author_thumbnail: author_thumbnail,
-              subscriber_count: subscriber_count,
-              video_count:      video_count,
-              description_html: description_html,
-              auto_generated:   auto_generated,
-            })
-          elsif i = item["gridPlaylistRenderer"]?
-            title = i["title"]["runs"].as_a[0]?.try &.["text"].as_s || ""
-            plid = i["playlistId"]?.try &.as_s || ""
-
-            video_count = i["videoCountText"]["runs"].as_a[0]?.try &.["text"].as_s.gsub(/\D/, "").to_i || 0
-            playlist_thumbnail = i["thumbnail"]["thumbnails"][0]?.try &.["url"]?.try &.as_s || ""
-
-            items << SearchPlaylist.new({
-              title:       title,
-              id:          plid,
-              author:      author_fallback || "",
-              ucid:        author_id_fallback || "",
-              video_count: video_count,
-              videos:      [] of SearchPlaylistVideo,
-              thumbnail:   playlist_thumbnail,
-            })
-          elsif i = item["playlistRenderer"]?
-            title = i["title"]["simpleText"]?.try &.as_s || ""
-            plid = i["playlistId"]?.try &.as_s || ""
-
-            video_count = i["videoCount"]?.try &.as_s.to_i || 0
-            playlist_thumbnail = i["thumbnails"].as_a[0]?.try &.["thumbnails"]?.try &.as_a[0]?.try &.["url"].as_s || ""
-
-            author_info = i["shortBylineText"]?.try &.["runs"].as_a[0]?
-            author = author_info.try &.["text"].as_s || author_fallback || ""
-            author_id = author_info.try &.["navigationEndpoint"]?.try &.["browseEndpoint"]["browseId"].as_s || author_id_fallback || ""
-
-            videos = i["videos"]?.try &.as_a.map do |v|
-              v = v["childVideoRenderer"]
-              v_title = v["title"]["simpleText"]?.try &.as_s || ""
-              v_id = v["videoId"]?.try &.as_s || ""
-              v_length_seconds = v["lengthText"]?.try &.["simpleText"]?.try { |t| decode_length_seconds(t.as_s) } || 0
-              SearchPlaylistVideo.new({
-                title:          v_title,
-                id:             v_id,
-                length_seconds: v_length_seconds,
-              })
-            end || [] of SearchPlaylistVideo
-
-            # TODO: i["publishedTimeText"]?
-
-            items << SearchPlaylist.new({
-              title:       title,
-              id:          plid,
-              author:      author,
-              ucid:        author_id,
-              video_count: video_count,
-              videos:      videos,
-              thumbnail:   playlist_thumbnail,
-            })
-          elsif i = item["radioRenderer"]? # Mix
-            # TODO
-          elsif i = item["showRenderer"]? # Show
-            # TODO
-          elsif i = item["shelfRenderer"]?
-          elsif i = item["horizontalCardListRenderer"]?
-          elsif i = item["searchPyvRenderer"]? # Ad
-          end
-        } }
+  channel_v2_response = initial_data
+    .try &.["response"]?
+    .try &.["continuationContents"]?
+    .try &.["gridContinuation"]?
+    .try &.["items"]?
+
+  if channel_v2_response
+    channel_v2_response.try &.as_a.each { |item|
+        extract_item(item, author_fallback, author_id_fallback)
+          .try { |t| items << t }
+    }
+  else
+    initial_data.try { |t| t["contents"]? || t["response"]? }
+      .try { |t| t["twoColumnBrowseResultsRenderer"]?.try &.["tabs"].as_a.select(&.["tabRenderer"]?.try &.["selected"].as_bool)[0]?.try &.["tabRenderer"]["content"] ||
+        t["twoColumnSearchResultsRenderer"]?.try &.["primaryContents"] ||
+        t["continuationContents"]? }
+      .try { |t| t["sectionListRenderer"]? || t["sectionListContinuation"]? }
+      .try &.["contents"].as_a
+        .each { |c| c.try &.["itemSectionRenderer"]?.try &.["contents"].as_a
+          .try { |t| t[0]?.try &.["shelfRenderer"]?.try &.["content"]["expandedShelfContentsRenderer"]?.try &.["items"].as_a ||
+            t[0]?.try &.["gridRenderer"]?.try &.["items"].as_a || t }
+          .each { |item|
+            extract_item(item, author_fallback, author_id_fallback)
+              .try { |t| items << t }
+          } }
+    end
 
   items
 end