Add author thumbnails to playlist endpoint

src/invidious.cr

@@ -2839,6 +2839,20 @@ get "/api/v1/playlists/:plid" do |env|
       json.field "authorId", playlist.ucid
       json.field "authorUrl", "/channel/#{playlist.ucid}"
 
+      json.field "authorThumbnails" do
+        json.array do
+          qualities = [32, 48, 76, 100, 176, 512]
+
+          qualities.each do |quality|
+            json.object do
+              json.field "url", playlist.author_thumbnail.gsub("=s100-", "=s#{quality}-")
+              json.field "width", quality
+              json.field "height", quality
+            end
+          end
+        end
+      end
+
       json.field "description", playlist.description
       json.field "descriptionHtml", playlist.description_html
       json.field "videoCount", playlist.video_count

src/invidious/playlists.cr

@@ -3,6 +3,7 @@ class Playlist
     title:            String,
     id:               String,
     author:           String,
+    author_thumbnail: String,
     ucid:             String,
     description:      String,
     description_html: String,
@@ -164,6 +165,8 @@ def fetch_playlist(plid)
 
   anchor = document.xpath_node(%q(//ul[@class="pl-header-details"])).not_nil!
   author = anchor.xpath_node(%q(.//li[1]/a)).not_nil!.content
+  author_thumbnail = document.xpath_node(%q(//img[@class="channel-header-profile-image"])).try &.["src"]
+  author_thumbnail ||= ""
   ucid = anchor.xpath_node(%q(.//li[1]/a)).not_nil!["href"].split("/")[2]
 
   video_count = anchor.xpath_node(%q(.//li[2])).not_nil!.content.delete("videos, ").to_i
@@ -181,6 +184,7 @@ def fetch_playlist(plid)
     title,
     plid,
     author,
+    author_thumbnail,
     ucid,
     description,
     description_html,