From ec4a22687fa386d5e61c4975578f11306b647ccf Mon Sep 17 00:00:00 2001
From: Triplesalt <39653793+Triplesalt@users.noreply.github.com>
Date: Fri, 23 Oct 2020 03:40:07 +0200
Subject: [PATCH] Update get_about_info for polymer (iv-org/invidious#1423)
 (#1429)

Update get_about_info for polymer (iv-org/invidious#1423)
---
 src/invidious/channels.cr       | 134 ++++++++++++++++++++------------
 src/invidious/views/channel.ecr |   2 +-
 2 files changed, 85 insertions(+), 51 deletions(-)

diff --git a/src/invidious/channels.cr b/src/invidious/channels.cr
index 18bdac09..dce9e6aa 100644
--- a/src/invidious/channels.cr
+++ b/src/invidious/channels.cr
@@ -775,10 +775,12 @@ def extract_channel_community_cursor(continuation)
   cursor
 end
 
+INITDATA_PREQUERY = "window[\"ytInitialData\"] = {"
+
 def get_about_info(ucid, locale)
-  about = YT_POOL.client &.get("/channel/#{ucid}/about?disable_polymer=1&gl=US&hl=en")
+  about = YT_POOL.client &.get("/channel/#{ucid}/about?gl=US&hl=en")
   if about.status_code != 200
-    about = YT_POOL.client &.get("/user/#{ucid}/about?disable_polymer=1&gl=US&hl=en")
+    about = YT_POOL.client &.get("/user/#{ucid}/about?gl=US&hl=en")
   end
 
   if md = about.headers["location"]?.try &.match(/\/channel\/(?<ucid>UC[a-zA-Z0-9_-]{22})/)
@@ -790,6 +792,17 @@ def get_about_info(ucid, locale)
     raise error_message
   end
 
+  initdata_pre = about.body.index(INITDATA_PREQUERY)
+  initdata_post = initdata_pre.nil? ? nil : about.body.index("};", initdata_pre)
+  if initdata_post.nil?
+    about = XML.parse_html(about.body)
+    error_message = about.xpath_node(%q(//div[@class="yt-alert-content"])).try &.content.strip
+    error_message ||= translate(locale, "Could not get channel info.")
+    raise error_message
+  end
+  initdata_pre = initdata_pre.not_nil! + INITDATA_PREQUERY.size - 1
+
+  initdata = JSON.parse(about.body[initdata_pre, initdata_post - initdata_pre + 1])
   about = XML.parse_html(about.body)
 
   if about.xpath_node(%q(//div[contains(@class, "channel-empty-message")]))
@@ -797,73 +810,94 @@ def get_about_info(ucid, locale)
     raise error_message
   end
 
-  if about.xpath_node(%q(//span[contains(@class,"qualified-channel-title-text")]/a)).try &.content.empty?
-    error_message = about.xpath_node(%q(//div[@class="yt-alert-content"])).try &.content.strip
-    error_message ||= translate(locale, "Could not get channel info.")
-    raise error_message
-  end
-
-  author = about.xpath_node(%q(//span[contains(@class,"qualified-channel-title-text")]/a)).not_nil!.content
-  author_url = about.xpath_node(%q(//span[contains(@class,"qualified-channel-title-text")]/a)).not_nil!["href"]
-  author_thumbnail = about.xpath_node(%q(//img[@class="channel-header-profile-image"])).not_nil!["src"]
+  author = about.xpath_node(%q(//meta[@name="title"])).not_nil!["content"]
+  author_url = about.xpath_node(%q(//link[@rel="canonical"])).not_nil!["href"]
+  author_thumbnail = about.xpath_node(%q(//link[@rel="image_src"])).not_nil!["href"]
 
   ucid = about.xpath_node(%q(//meta[@itemprop="channelId"])).not_nil!["content"]
 
-  banner = about.xpath_node(%q(//div[@id="gh-banner"]/style)).not_nil!.content
-  banner = "https:" + banner.match(/background-image: url\((?<url>[^)]+)\)/).not_nil!["url"]
+  # Raises a KeyError on failure.
+  banners = initdata["header"]["c4TabbedHeaderRenderer"]?.try &.["banner"]?.try &.["thumbnails"]?
+  banner = banners.try &.[-1]?.try &.["url"].as_s?
 
-  if banner.includes? "channels/c4/default_banner"
-    banner = nil
-  end
+  # if banner.includes? "channels/c4/default_banner"
+  #  banner = nil
+  # end
 
-  description_html = about.xpath_node(%q(//div[contains(@class,"about-description")])).try &.to_s ||
-                     %(<div class="about-description branded-page-box-padding"><pre></pre></div>)
+  description = initdata["metadata"]["channelMetadataRenderer"]?.try &.["description"]?.try &.as_s? || ""
+  description_html = HTML.escape(description).gsub("\n", "<br>")
 
   paid = about.xpath_node(%q(//meta[@itemprop="paid"])).not_nil!["content"] == "True"
   is_family_friendly = about.xpath_node(%q(//meta[@itemprop="isFamilyFriendly"])).not_nil!["content"] == "True"
   allowed_regions = about.xpath_node(%q(//meta[@itemprop="regionsAllowed"])).not_nil!["content"].split(",")
 
-  related_channels = about.xpath_nodes(%q(//div[contains(@class, "branded-page-related-channels")]/ul/li))
-  related_channels = related_channels.map do |node|
-    related_id = node["data-external-id"]?
-    related_id ||= ""
+  related_channels = initdata["contents"]["twoColumnBrowseResultsRenderer"]
+    .["secondaryContents"]?.try &.["browseSecondaryContentsRenderer"]["contents"][0]?
+    .try &.["verticalChannelSectionRenderer"]?.try &.["items"]?.try &.as_a.map do |node|
+      renderer = node["miniChannelRenderer"]?
+      related_id = renderer.try &.["channelId"]?.try &.as_s?
+      related_id ||= ""
 
-    anchor = node.xpath_node(%q(.//h3[contains(@class, "yt-lockup-title")]/a))
-    related_title = anchor.try &.["title"]
-    related_title ||= ""
+      related_title = renderer.try &.["title"]?.try &.["simpleText"]?.try &.as_s?
+      related_title ||= ""
 
-    related_author_url = anchor.try &.["href"]
-    related_author_url ||= ""
+      related_author_url = renderer.try &.["navigationEndpoint"]?.try &.["commandMetadata"]?.try &.["webCommandMetadata"]?
+        .try &.["url"]?.try &.as_s?
+      related_author_url ||= ""
 
-    related_author_thumbnail = node.xpath_node(%q(.//img)).try &.["data-thumb"]
-    related_author_thumbnail ||= ""
+      related_author_thumbnails = renderer.try &.["thumbnail"]?.try &.["thumbnails"]?.try &.as_a?
+      related_author_thumbnails ||= [] of JSON::Any
 
-    AboutRelatedChannel.new({
-      ucid:             related_id,
-      author:           related_title,
-      author_url:       related_author_url,
-      author_thumbnail: related_author_thumbnail,
-    })
-  end
+      related_author_thumbnail = ""
+      if related_author_thumbnails.size > 0
+        related_author_thumbnail = related_author_thumbnails[-1]["url"]?.try &.as_s?
+        related_author_thumbnail ||= ""
+      end
 
-  joined = about.xpath_node(%q(//span[contains(., "Joined")]))
-    .try &.content.try { |text| Time.parse(text, "Joined %b %-d, %Y", Time::Location.local) } || Time.unix(0)
+      AboutRelatedChannel.new({
+        ucid:             related_id,
+        author:           related_title,
+        author_url:       related_author_url,
+        author_thumbnail: related_author_thumbnail,
+      })
+    end
+  related_channels ||= [] of AboutRelatedChannel
 
-  total_views = about.xpath_node(%q(//span[contains(., "views")]/b))
-    .try &.content.try &.gsub(/\D/, "").to_i64? || 0_i64
-
-  sub_count = about.xpath_node(%q(.//span[contains(@class, "subscriber-count")]))
-    .try &.["title"].try { |text| short_text_to_number(text) } || 0
-
-  # Auto-generated channels
-  # https://support.google.com/youtube/answer/2579942
+  total_views = 0_i64
+  joined = Time.unix(0)
+  tabs = [] of String
   auto_generated = false
-  if about.xpath_node(%q(//ul[@class="about-custom-links"]/li/a[@title="Auto-generated by YouTube"])) ||
-     about.xpath_node(%q(//span[@class="qualified-channel-title-badge"]/span[@title="Auto-generated by YouTube"]))
-    auto_generated = true
+
+  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 !channel_about_meta.nil?
+        total_views = channel_about_meta["viewCountText"]?.try &.["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, node| acc + node["text"].as_s }
+          .try { |text| Time.parse(text, "Joined %b %-d, %Y", Time::Location.local) } || Time.unix(0)
+
+        # 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
+    end
+    tabs = tabs_json.reject { |node| node["tabRenderer"]?.nil? }.map { |node| node["tabRenderer"]["title"].as_s.downcase }
   end
 
-  tabs = about.xpath_nodes(%q(//ul[@id="channel-navigation-menu"]/li/a/span)).map { |node| node.content.downcase }
+  sub_count = initdata["header"]["c4TabbedHeaderRenderer"]?.try &.["subscriberCountText"]?.try &.["simpleText"]?.try &.as_s?
+    .try { |text| short_text_to_number(text.split(" ")[0]) } || 0
 
   AboutChannel.new({
     ucid:               ucid,
diff --git a/src/invidious/views/channel.ecr b/src/invidious/views/channel.ecr
index 4e9c7a63..caa0ad0e 100644
--- a/src/invidious/views/channel.ecr
+++ b/src/invidious/views/channel.ecr
@@ -28,7 +28,7 @@
 </div>
 
 <div class="h-box">
-    <p><span style="white-space:pre-wrap"><%= XML.parse_html(channel.description_html).xpath_node(%q(.//pre)).try &.content %></span></p>
+    <p><span style="white-space:pre-wrap"><%= channel.description_html %></span></p>
 </div>
 
 <div class="h-box">