From 344ccf3b03f640fa65504d45a1fa8df87e1c744c Mon Sep 17 00:00:00 2001
From: Samantaz Fox <coding@samantaz.fr>
Date: Tue, 13 Apr 2021 19:33:37 +0200
Subject: [PATCH] Use '/youtubei/v1/browse' endpoint for playlists

---
 src/invidious/helpers/youtube_api.cr | 36 ++++++++++++++++++++++++----
 src/invidious/playlists.cr           | 20 +++-------------
 2 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/src/invidious/helpers/youtube_api.cr b/src/invidious/helpers/youtube_api.cr
index dc3a7eb5..1b8f6dae 100644
--- a/src/invidious/helpers/youtube_api.cr
+++ b/src/invidious/helpers/youtube_api.cr
@@ -8,15 +8,20 @@ HARDCODED_CLIENT_VERS = "2.20210330.08.00"
 
 ####################################################################
 # request_youtube_api_browse(continuation)
+# request_youtube_api_browse(browse_id, params)
 #
 # Requests the youtubei/vi/browse endpoint with the required headers
 # to get JSON in en-US (english US).
 #
-# The requested data is a continuation token (ctoken). Depending on
-# this token's contents, the returned data can be comments, playlist
-# videos, search results, channel community tab, ...
+# The requested data can either be:
 #
-def request_youtube_api_browse(continuation)
+#  - A continuation token (ctoken). Depending on this token's
+#    contents, the returned data can be comments, playlist videos,
+#    search results, channel community tab, ...
+#
+#  - A playlist ID (parameters MUST be an empty string)
+#
+def request_youtube_api_browse(continuation : String)
   # JSON Request data, required by the API
   data = {
     "context": {
@@ -33,6 +38,29 @@ def request_youtube_api_browse(continuation)
   return _youtube_api_post_json("/youtubei/v1/browse", data)
 end
 
+def request_youtube_api_browse(browse_id : String, params : String)
+  # JSON Request data, required by the API
+  data = {
+    "browseId" => browse_id,
+    "context"  => {
+      "client" => {
+        "hl"            => "en",
+        "gl"            => "US",
+        "clientName"    => "WEB",
+        "clientVersion" => HARDCODED_CLIENT_VERS,
+      },
+    },
+  }
+
+  # Append the additionnal parameters if those were provided
+  # (this is required for channel info, playlist and community, e.g)
+  if params != ""
+    data["params"] = params
+  end
+
+  return _youtube_api_post_json("/youtubei/v1/browse", data)
+end
+
 ####################################################################
 # request_youtube_api_search(search_query, params, region)
 #
diff --git a/src/invidious/playlists.cr b/src/invidious/playlists.cr
index 150f1c15..fe7f82f3 100644
--- a/src/invidious/playlists.cr
+++ b/src/invidious/playlists.cr
@@ -361,16 +361,7 @@ def fetch_playlist(plid, locale)
     plid = "UU#{plid.lchop("UC")}"
   end
 
-  response = YT_POOL.client &.get("/playlist?list=#{plid}&hl=en")
-  if response.status_code != 200
-    if response.headers["location"]?.try &.includes? "/sorry/index"
-      raise InfoException.new("Could not extract playlist info. Instance is likely blocked.")
-    else
-      raise InfoException.new("Not a playlist.")
-    end
-  end
-
-  initial_data = extract_initial_data(response.body)
+  initial_data = request_youtube_api_browse("VL" + plid, params: "")
 
   playlist_sidebar_renderer = initial_data["sidebar"]?.try &.["playlistSidebarRenderer"]?.try &.["items"]?
   raise InfoException.new("Could not extract playlistSidebarRenderer.") if !playlist_sidebar_renderer
@@ -453,15 +444,10 @@ def get_playlist_videos(db, playlist, offset, locale = nil, continuation = nil)
       ctoken = produce_playlist_continuation(playlist.id, offset)
       initial_data = request_youtube_api_browse(ctoken)
     else
-      response = YT_POOL.client &.get("/playlist?list=#{playlist.id}&gl=US&hl=en")
-      initial_data = extract_initial_data(response.body)
+      initial_data = request_youtube_api_browse("VL" + playlist.id, params: "")
     end
 
-    if initial_data
-      return extract_playlist_videos(initial_data)
-    else
-      return [] of PlaylistVideo
-    end
+    return extract_playlist_videos(initial_data)
   end
 end