API: Parse channel's tags (#4294)

Example from an auto generated channel (Minecraft - Topic):
/api/v1/channels/UCQvWX73GQygcwXOTSf_VDVg

{
  ...
  "tags":[
    "Video game","Indie game","Xbox One","New Nintendo 3DS",
    "PS3","Nintendo Switch","Wii U","Fire OS",
    "Mac operating systems","Apple TV","Xbox 360",
    "PlayStation Vita","PS4","Windows","Linux","Nintendo 3DS",
    "iOS","Windows Phone","iPadOS","Java","Android","tvOS",
    "ChromeOS"
  ]
  ...
}

Example from another channel (Mr Beast):
/api/v1/channels/UCX6OQ3DkcsbYNE6H8uQQuVA

{
  ...
  "tags":["mrbeast6000","beast","mrbeast","Mr.Beast","mr"]
  ...
}

No associated issue

src/invidious/channels/about.cr

@@ -14,6 +14,7 @@ record AboutChannel,
   is_family_friendly : Bool,
   allowed_regions : Array(String),
   tabs : Array(String),
+  tags : Array(String),
   verified : Bool
 
 def get_about_info(ucid, locale) : AboutChannel
@@ -43,6 +44,8 @@ def get_about_info(ucid, locale) : AboutChannel
     auto_generated = true
   end
 
+  tags = [] of String
+
   if auto_generated
     author = initdata["header"]["interactiveTabbedHeaderRenderer"]["title"]["simpleText"].as_s
     author_url = initdata["microformat"]["microformatDataRenderer"]["urlCanonical"].as_s
@@ -52,7 +55,13 @@ def get_about_info(ucid, locale) : AboutChannel
     banners = initdata["header"]["interactiveTabbedHeaderRenderer"]?.try &.["banner"]?.try &.["thumbnails"]?
     banner = banners.try &.[-1]?.try &.["url"].as_s?
 
-    description_node = initdata["header"]["interactiveTabbedHeaderRenderer"]["description"]
+    description_base_node = initdata["header"]["interactiveTabbedHeaderRenderer"]["description"]
+    # some channels have the description in a simpleText
+    # ex: https://www.youtube.com/channel/UCQvWX73GQygcwXOTSf_VDVg/
+    description_node = description_base_node.dig?("simpleText") || description_base_node
+
+    tags = initdata.dig?("header", "interactiveTabbedHeaderRenderer", "badges")
+      .try &.as_a.map(&.["metadataBadgeRenderer"]["label"].as_s) || [] of String
   else
     author = initdata["metadata"]["channelMetadataRenderer"]["title"].as_s
     author_url = initdata["metadata"]["channelMetadataRenderer"]["channelUrl"].as_s
@@ -70,6 +79,7 @@ def get_about_info(ucid, locale) : AboutChannel
     # end
 
     description_node = initdata["metadata"]["channelMetadataRenderer"]?.try &.["description"]?
+    tags = initdata.dig?("microformat", "microformatDataRenderer", "tags").try &.as_a.map(&.as_s) || [] of String
   end
 
   is_family_friendly = initdata["microformat"]["microformatDataRenderer"]["familySafe"].as_bool
@@ -131,7 +141,8 @@ def get_about_info(ucid, locale) : AboutChannel
       # ["description"]["simpleText"] and ["primaryLinks"][0]["title"]["simpleText"]
       auto_generated = (
         (channel_about_meta["primaryLinks"]?.try &.size) == 1 && \
-           extract_text(channel_about_meta.dig?("primaryLinks", 0, "title")) == "Auto-generated by YouTube"
+           extract_text(channel_about_meta.dig?("primaryLinks", 0, "title")) == "Auto-generated by YouTube" ||
+        channel_about_meta.dig?("links", 0, "channelExternalLinkViewModel", "title", "content").try &.as_s == "Auto-generated by YouTube"
       )
     end
   end
@@ -155,6 +166,7 @@ def get_about_info(ucid, locale) : AboutChannel
     is_family_friendly: is_family_friendly,
     allowed_regions: allowed_regions,
     tabs: tab_names,
+    tags: tags,
     verified: author_verified || false,
   )
 end

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

@@ -90,6 +90,7 @@ module Invidious::Routes::API::V1::Channels
 
         json.field "allowedRegions", channel.allowed_regions
         json.field "tabs", channel.tabs
+        json.field "tags", channel.tags
         json.field "authorVerified", channel.verified
 
         json.field "latestVideos" do