channel: use extractor utils to parse tabs (+ code cleaning)

src/invidious/channels/about.cr

@@ -100,34 +100,40 @@ def get_about_info(ucid, locale) : AboutChannel
   total_views = 0_i64
   joined = Time.unix(0)
 
-  tabs = [] of String
+  tab_names = [] of String
 
-  tabs_json = initdata["contents"]["twoColumnBrowseResultsRenderer"]["tabs"]?.try &.as_a?
-  if !tabs_json.nil?
-    # Retrieve information from the tabs array. The index we are looking for varies between channels.
-    tabs_json.each do |node|
-      # Try to find the about section which is located in only one of the tabs.
-      channel_about_meta = node["tabRenderer"]?.try &.["content"]?.try &.["sectionListRenderer"]?
-        .try &.["contents"]?.try &.[0]?.try &.["itemSectionRenderer"]?.try &.["contents"]?
-          .try &.[0]?.try &.["channelAboutFullMetadataRenderer"]?
+  if tabs_json = initdata["contents"]["twoColumnBrowseResultsRenderer"]["tabs"]?
+    # Get the name of the tabs available on this channel
+    tab_names = tabs_json.as_a
+      .compact_map(&.dig?("tabRenderer", "title").try &.as_s.downcase)
+
+    # Get the currently active tab ("About")
+    about_tab = extract_selected_tab(tabs_json)
+
+    # Try to find the about metadata section
+    channel_about_meta = about_tab.dig?(
+      "content",
+      "sectionListRenderer", "contents", 0,
+      "itemSectionRenderer", "contents", 0,
+      "channelAboutFullMetadataRenderer"
+    )
 
     if !channel_about_meta.nil?
-        total_views = channel_about_meta["viewCountText"]?.try &.["simpleText"]?.try &.as_s.gsub(/\D/, "").to_i64? || 0_i64
+      total_views = channel_about_meta.dig?("viewCountText", "simpleText").try &.as_s.gsub(/\D/, "").to_i64? || 0_i64
 
       # The joined text is split to several sub strings. The reduce joins those strings before parsing the date.
-        joined = channel_about_meta["joinedDateText"]?.try &.["runs"]?.try &.as_a.reduce("") { |acc, nd| acc + nd["text"].as_s }
+      joined = extract_text(channel_about_meta["joinedDateText"]?)
         .try { |text| Time.parse(text, "Joined %b %-d, %Y", Time::Location.local) } || Time.unix(0)
 
       # Normal Auto-generated channels
       # https://support.google.com/youtube/answer/2579942
-        # For auto-generated channels, channel_about_meta only has ["description"]["simpleText"] and ["primaryLinks"][0]["title"]["simpleText"]
-        if (channel_about_meta["primaryLinks"]?.try &.size || 0) == 1 && (channel_about_meta["primaryLinks"][0]?) &&
-           (channel_about_meta["primaryLinks"][0]["title"]?.try &.["simpleText"]?.try &.as_s? || "") == "Auto-generated by YouTube"
-          auto_generated = true
-        end
-      end
+      # For auto-generated channels, channel_about_meta only has
+      # ["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"
+      )
     end
-    tabs = tabs_json.reject { |node| node["tabRenderer"]?.nil? }.map(&.["tabRenderer"]["title"].as_s.downcase)
   end
 
   sub_count = initdata
@@ -148,7 +154,7 @@ def get_about_info(ucid, locale) : AboutChannel
     joined: joined,
     is_family_friendly: is_family_friendly,
     allowed_regions: allowed_regions,
-    tabs: tabs,
+    tabs: tab_names,
     verified: author_verified || false,
   )
 end