frontend: Add support for the "featured channels" page

locales/en-US.json

@@ -475,5 +475,6 @@
     "channel_tab_shorts_label": "Shorts",
     "channel_tab_streams_label": "Livestreams",
     "channel_tab_playlists_label": "Playlists",
-    "channel_tab_community_label": "Community"
+    "channel_tab_community_label": "Community",
+    "channel_tab_channels_label": "Channels"
 }

src/invidious/channels/about.cr

@@ -16,12 +16,6 @@ record AboutChannel,
   tabs : Array(String),
   verified : Bool
 
-record AboutRelatedChannel,
-  ucid : String,
-  author : String,
-  author_url : String,
-  author_thumbnail : String
-
 def get_about_info(ucid, locale) : AboutChannel
   begin
     # "EgVhYm91dA==" is the base64-encoded protobuf object {"2:string":"about"}
@@ -165,41 +159,15 @@ def get_about_info(ucid, locale) : AboutChannel
   )
 end
 
-def fetch_related_channels(about_channel : AboutChannel) : Array(AboutRelatedChannel)
-  # params is {"2:string":"channels"} encoded
-  channels = YoutubeAPI.browse(browse_id: about_channel.ucid, params: "EghjaGFubmVscw%3D%3D")
-
-  tabs = channels.dig?("contents", "twoColumnBrowseResultsRenderer", "tabs").try(&.as_a?) || [] of JSON::Any
-  tab = tabs.find(&.dig?("tabRenderer", "title").try(&.as_s?).try(&.== "Channels"))
-
-  return [] of AboutRelatedChannel if tab.nil?
-
-  items = tab.dig?(
-    "tabRenderer", "content",
-    "sectionListRenderer", "contents", 0,
-    "itemSectionRenderer", "contents", 0,
-    "gridRenderer", "items"
-  ).try &.as_a?
-
-  related = [] of AboutRelatedChannel
-  return related if (items.nil? || items.empty?)
-
-  items.each do |item|
-    renderer = item["gridChannelRenderer"]?
-    next if !renderer
-
-    related_id = renderer.dig("channelId").as_s
-    related_title = renderer.dig("title", "simpleText").as_s
-    related_author_url = renderer.dig("navigationEndpoint", "browseEndpoint", "canonicalBaseUrl").as_s
-    related_author_thumbnail = HelperExtractors.get_thumbnails(renderer)
-
-    related << AboutRelatedChannel.new(
-      ucid: related_id,
-      author: related_title,
-      author_url: related_author_url,
-      author_thumbnail: related_author_thumbnail,
-    )
+def fetch_related_channels(about_channel : AboutChannel, continuation : String? = nil) : {Array(SearchChannel), String?}
+  if continuation.nil?
+    # params is {"2:string":"channels"} encoded
+    initial_data = YoutubeAPI.browse(browse_id: about_channel.ucid, params: "EghjaGFubmVscw%3D%3D")
+  else
+    initial_data = YoutubeAPI.browse(continuation)
   end
 
-  return related
+  items, continuation = extract_items(initial_data)
+
+  return items.select(SearchChannel), continuation
 end

src/invidious/frontend/channel_page.cr

@@ -7,6 +7,7 @@ module Invidious::Frontend::ChannelPage
     Streams
     Playlists
     Community
+    Channels
   end
 
   def generate_tabs_links(locale : String, channel : AboutChannel, selected_tab : TabsAvailable)

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

@@ -102,31 +102,13 @@ module Invidious::Routes::API::V1::Channels
           json.array do
             # Fetch related channels
             begin
-              related_channels = fetch_related_channels(channel)
+              related_channels, _ = fetch_related_channels(channel)
             rescue ex
-              related_channels = [] of AboutRelatedChannel
+              related_channels = [] of SearchChannel
             end
 
             related_channels.each do |related_channel|
-              json.object do
-                json.field "author", related_channel.author
-                json.field "authorId", related_channel.ucid
-                json.field "authorUrl", related_channel.author_url
-
-                json.field "authorThumbnails" do
-                  json.array do
-                    qualities = {32, 48, 76, 100, 176, 512}
-
-                    qualities.each do |quality|
-                      json.object do
-                        json.field "url", related_channel.author_thumbnail.gsub(/=\d+/, "=s#{quality}")
-                        json.field "width", quality
-                        json.field "height", quality
-                      end
-                    end
-                  end
-                end
-              end
+              related_channel.to_json(locale, json)
             end
           end
         end # relatedChannels

src/invidious/routes/channels.cr

@@ -147,6 +147,26 @@ module Invidious::Routes::Channels
     templated "community"
   end
 
+  def self.channels(env)
+    data = self.fetch_basic_information(env)
+    return data if !data.is_a?(Tuple)
+
+    locale, user, subscriptions, continuation, ucid, channel = data
+
+    if channel.auto_generated
+      return env.redirect "/channel/#{channel.ucid}"
+    end
+
+    items, next_continuation = fetch_related_channels(channel, continuation)
+
+    # Featured/related channels can't be sorted
+    sort_options = [] of String
+    sort_by = nil
+
+    selected_tab = Frontend::ChannelPage::TabsAvailable::Channels
+    templated "channel"
+  end
+
   def self.about(env)
     data = self.fetch_basic_information(env)
     if !data.is_a?(Tuple)

src/invidious/routing.cr

@@ -119,6 +119,7 @@ module Invidious::Routing
     get "/channel/:ucid/streams", Routes::Channels, :streams
     get "/channel/:ucid/playlists", Routes::Channels, :playlists
     get "/channel/:ucid/community", Routes::Channels, :community
+    get "/channel/:ucid/channels", Routes::Channels, :channels
     get "/channel/:ucid/about", Routes::Channels, :about
     get "/channel/:ucid/live", Routes::Channels, :live
     get "/user/:user/live", Routes::Channels, :live

src/invidious/views/channel.ecr

@@ -8,6 +8,7 @@
     when .shorts?    then "/channel/#{ucid}/shorts"
     when .streams?   then "/channel/#{ucid}/streams"
     when .playlists? then "/channel/#{ucid}/playlists"
+    when .channels?  then "/channel/#{ucid}/channels"
     else
       "/channel/#{ucid}"
     end