implement youtube download

apps/cf/lib/application.ex

@@ -1,8 +1,8 @@
 defmodule CF.Application do
   use Application
 
-  # See http://elixir-lang.org/docs/stable/elixir/Application.html
-  # for more information on OTP Applications
+  require Logger
+
   def start(_type, _args) do
     import Supervisor.Spec
 
@@ -13,13 +13,20 @@ defmodule CF.Application do
       # Misc workers
       worker(CF.Accounts.UsernameGenerator, []),
       # Sweep tokens from db
-      worker(Guardian.DB.Token.SweeperServer, [])
+      worker(Guardian.DB.Token.SweeperServer, []),
     ]
 
-    # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
-    # for other strategies and supported options
     opts = [strategy: :one_for_one, name: CF.Supervisor]
-    Supervisor.start_link(children, opts)
+
+    goth_credentials = get_goth_worker_credentials()
+    if goth_credentials do
+      IO.inspect(goth_credentials)
+      source = {:refresh_token, goth_credentials, []}
+      children = [{Goth, name: CF.Goth, source: source}] ++ children
+      Supervisor.start_link(children, opts)
+    else
+      Supervisor.start_link(children, opts)
+    end
   end
 
   def version() do
@@ -36,4 +43,23 @@ defmodule CF.Application do
   def env() do
     (Kernel.function_exported?(Mix, :env, 0) && Mix.env()) || :prod
   end
+
+  defp get_goth_worker_credentials() do
+    System.fetch_env("GOOGLE_APPLICATION_CREDENTIALS_JSON")
+    |> case do
+      {:ok, credentials} ->
+        case Jason.decode(credentials) do
+          {:ok, decoded} ->
+            Logger.info("GOOGLE_APPLICATION_CREDENTIALS_JSON found")
+            decoded
+          {:error, _} ->
+            Logger.error("GOOGLE_APPLICATION_CREDENTIALS_JSON is not a valid JSON")
+            nil
+        end
+
+      _ ->
+        Logger.warn("GOOGLE_APPLICATION_CREDENTIALS_JSON not found")
+        nil
+    end
+  end
 end

apps/cf/lib/videos/captions_fetcher_youtube.ex

@@ -97,37 +97,16 @@ defmodule CF.Videos.CaptionsFetcherYoutube do
 
   # Below is an implementation using the official YouTube API, but it requires OAuth2 authentication.
   # It is left here for reference, in case we loose access to the unofficial API.
-  # defp fetch_captions_content_with_official_api(video_id, locale) do
-  #   # TODO: Continue dev here. See https://www.perplexity.ai/search/Can-you-show-jioyCtw.S4yrL8mlIBdqGg
-  #   {:ok, token} = Goth.Token.for_scope("https://www.googleapis.com/auth/youtube.force-ssl")
-  #   conn = YouTubeConnection.new(token.token)
-  # {:ok, captions} = GoogleApi.YouTube.V3.Api.Captions.youtube_captions_list(conn, ["snippet"], video_id, [])
-  # {
-  #   "kind": "youtube#captionListResponse",
-  #   "etag": "kMTAKpyU_VGu7GxgEnxXHqcuEXM",
-  #   "items": [
-  #     {
-  #       "kind": "youtube#caption",
-  #       "etag": "tWo68CIcRRFZA0oXPt8HGxCYia4",
-  #       "id": "AUieDaZJxYug0L5YNAw_31GbXz73b0CPXCDFlsPNSNe7KQvuv1g",
-  #       "snippet": {
-  #         "videoId": "v2IoEhuho2k",
-  #         "lastUpdated": "2024-06-16T18:45:12.56697Z",
-  #         "trackKind": "asr",
-  #         "language": "fr",
-  #         "name": "",
-  #         "audioTrackType": "unknown",
-  #         "isCC": false,
-  #         "isLarge": false,
-  #         "isEasyReader": false,
-  #         "isDraft": false,
-  #         "isAutoSynced": false,
-  #         "status": "serving"
-  #       }
-  #     }
-  #   ]
-  # }
-  # caption_id = List.first(captions.items).id # TODO inspect to pick the right caption
-  # {:ok, caption} = GoogleApi.YouTube.V3.Api.Captions.youtube_captions_download(conn, caption_id, [])
-  # end
+  def fetch_captions_content_with_official_api(video_id, locale) do
+    {:ok, token} = Goth.fetch(CF.Goth)
+    conn = GoogleApi.YouTube.V3.Connection.new(token.token)
+
+    IO.inspect(token)
+
+    {:ok, result} = GoogleApi.YouTube.V3.Api.Captions.youtube_captions_list(conn, ["snippet"], video_id, [])
+    IO.inspect(Enum.count(result.items))
+    caption_id = List.first(result.items).id
+    {:ok, caption} =
+      GoogleApi.YouTube.V3.Api.Captions.youtube_captions_download(conn, caption_id, []) #FAILS, you can only download captions for your own videos :-(
+  end
 end

apps/cf/mix.exs

@@ -61,6 +61,7 @@ defmodule CF.Mixfile do
       {:jason, "~> 1.4"},
       {:openai, "~> 0.6.1"},
       {:sweet_xml, "~> 0.7.4"},
+      {:goth, "~> 1.3"},
 
       # ---- Internal ----
       {:db, in_umbrella: true},