feat: Add job to download captions

apps/cf_jobs/lib/jobs/download_captions.ex

@@ -0,0 +1,57 @@
+defmodule CF.Jobs.DownloadCaptions do
+  @behaviour CF.Jobs.Job
+
+  require Logger
+  import Ecto.Query
+  import ScoutApm.Tracing
+
+  alias DB.Repo
+  alias DB.Schema.UserAction
+  alias DB.Schema.UsersActionsReport
+
+  alias CF.Jobs.ReportManager
+
+  @name :download_captions
+  @analyser_id UsersActionsReport.analyser_id(@name)
+
+  # --- Client API ---
+
+  def name, do: @name
+
+  def start_link() do
+    GenServer.start_link(__MODULE__, :ok, name: __MODULE__)
+  end
+
+  def init(args) do
+    {:ok, args}
+  end
+
+  # 1 minute
+  @timeout 60_000
+  def update() do
+    GenServer.call(__MODULE__, :download_captions, @timeout)
+  end
+
+  # --- Server callbacks ---
+  @transaction_opts [type: "background", name: "download_captions"]
+  def handle_call(:download_captions, _from, _state) do
+    get_videos()
+    |> Enum.map(fn video ->
+      Logger.info("Downloading captions for video #{video.id}")
+      download_captions(video)
+    end)
+
+    {:reply, :ok, :ok}
+  end
+
+  # Get all videos that need new captions. We fetch new captions:
+  # - For any videos that doesn't have any captions yet
+  # - For videos whose captions haven't been updated in the last 30 days
+  defp get_videos() do
+    Repo.all(
+      from v in DB.Schema.Video,
+      where: v.captions_updated_at == nil or v.captions_updated_at < DateTime.utc_now() - 30,
+      preload: [:channel]
+    )
+  end
+end