Add 'view as playlist' option to trending page

src/invidious.cr

@@ -1955,7 +1955,7 @@ get "/feed/trending" do |env|
   region ||= "US"
 
   begin
-    trending = fetch_trending(trending_type, proxies, region, locale)
+    trending, plid = fetch_trending(trending_type, proxies, region, locale)
   rescue ex
     error_message = "#{ex.message}"
     next templated "error"
@@ -3205,7 +3205,7 @@ get "/api/v1/trending" do |env|
   trending_type = env.params.query["type"]?
 
   begin
-    trending = fetch_trending(trending_type, proxies, region, locale)
+    trending, plid = fetch_trending(trending_type, proxies, region, locale)
   rescue ex
     error_message = {"error" => ex.message}.to_json
     env.response.status_code = 500

src/invidious/trending.cr

@@ -7,6 +7,8 @@ def fetch_trending(trending_type, proxies, region, locale)
   region = region.upcase
 
   trending = ""
+  plid = nil
+
   if trending_type && trending_type != "Default"
     trending_type = trending_type.downcase.capitalize
 
@@ -23,9 +25,11 @@ def fetch_trending(trending_type, proxies, region, locale)
     url = tabs.select { |tab| tab["channelListSubMenuAvatarRenderer"]["title"]["simpleText"] == trending_type }[0]?
 
     if url
+      url["channelListSubMenuAvatarRenderer"]["navigationEndpoint"]["commandMetadata"]["webCommandMetadata"]["url"]
       url = url["channelListSubMenuAvatarRenderer"]["navigationEndpoint"]["commandMetadata"]["webCommandMetadata"]["url"].as_s
       url += "&disable_polymer=1&gl=#{region}&hl=en"
       trending = client.get(url).body
+      plid = extract_plid(url)
     else
       trending = client.get("/feed/trending?gl=#{region}&hl=en&disable_polymer=1").body
     end
@@ -37,5 +41,37 @@ def fetch_trending(trending_type, proxies, region, locale)
   nodeset = trending.xpath_nodes(%q(//ul/li[@class="expanded-shelf-content-item-wrapper"]))
   trending = extract_videos(nodeset)
 
-  return trending
+  return {trending, plid}
+end
+
+def extract_plid(url)
+  wrapper = HTTP::Params.parse(URI.parse(url).query.not_nil!)["bp"]
+
+  wrapper = URI.unescape(wrapper)
+  wrapper = Base64.decode(wrapper)
+
+  # 0xe2 0x02 0x2e
+  wrapper += 3
+
+  # 0x0a
+  wrapper += 1
+
+  # Looks like "/m/[a-z0-9]{5}", not sure what it does here
+
+  item_size = wrapper[0]
+  wrapper += 1
+  item = wrapper[0, item_size]
+  wrapper += item.size
+
+  # 0x12
+  wrapper += 1
+
+  plid_size = wrapper[0]
+  wrapper += 1
+  plid = wrapper[0, plid_size]
+  wrapper += plid.size
+
+  plid = String.new(plid)
+
+  return plid
 end

src/invidious/views/trending.ecr

@@ -6,9 +6,10 @@
 <%= rendered "components/feed_menu" %>
 
 <div class="pure-g h-box">
-    <div class="pure-u-2-3">
-        <form class="pure-form pure-form-aligned" action="/feed/trending" method="get">
-        </form>
+    <div style="align-self:flex-end" class="pure-u-2-3">
+        <% if plid %>
+        <a href="/playlist?list=<%= plid %>"><%= translate(locale, "View as playlist") %></a>
+        <% end %>
     </div>
     <div class="pure-u-1-3">
         <div class="pure-g" style="text-align:right;">