Async barcode scan batch import for 2+ new records

When barcode scan results contain at least 2 new records,
enqueue individual Oban jobs instead of importing synchronously.
Wishlisted/collected/not_found results still process synchronously.

lib/music_library/barcode_scan.ex

@@ -5,6 +5,7 @@ defmodule MusicLibrary.BarcodeScan do
 
   alias MusicLibrary.BarcodeScan.Result
   alias MusicLibrary.Records
+  alias MusicLibrary.Worker.ImportFromMusicbrainzRelease
 
   @spec scan(String.t()) :: {:ok, Result.t()} | {:error, term()}
   def scan(number) do
@@ -31,6 +32,32 @@ defmodule MusicLibrary.BarcodeScan do
     end
   end
 
+  @spec should_import_async?([Result.t()]) :: boolean()
+  def should_import_async?(scan_results) do
+    Enum.count(scan_results, &(&1.status == :new)) >= 2
+  end
+
+  @spec import_results_async([Result.t()], DateTime.t()) ::
+          {:ok, sync_errors :: [{String.t(), term()}], async_count :: non_neg_integer()}
+  def import_results_async(scan_results, current_time) do
+    {new_results, other_results} = Enum.split_with(scan_results, &(&1.status == :new))
+
+    sync_errors = import_results(other_results, current_time)
+
+    Enum.each(new_results, fn scan_result ->
+      %{
+        "release_id" => scan_result.release.id,
+        "format" => MusicBrainz.ReleaseSearchResult.format(scan_result.release),
+        "purchased_at" => DateTime.to_iso8601(current_time),
+        "selected_release_id" => scan_result.release.id
+      }
+      |> ImportFromMusicbrainzRelease.new()
+      |> Oban.insert!()
+    end)
+
+    {:ok, sync_errors, length(new_results)}
+  end
+
   @spec import_results([Result.t()], DateTime.t()) :: [{String.t(), term()}]
   def import_results(scan_results, current_time) do
     Enum.reduce(scan_results, [], fn scan_result, errors ->

lib/music_library/worker/import_from_musicbrainz_release.ex

@@ -0,0 +1,30 @@
+defmodule MusicLibrary.Worker.ImportFromMusicbrainzRelease do
+  @moduledoc """
+  Imports a record from a MusicBrainz release in the background.
+
+  Used by barcode scan batch imports when there are multiple new records to import.
+  """
+
+  use Oban.Worker, queue: :music_brainz, max_attempts: 3
+
+  @impl Oban.Worker
+  def perform(%Oban.Job{args: %{"release_id" => release_id} = args}) do
+    opts = [
+      format: args["format"],
+      purchased_at: parse_datetime(args["purchased_at"]),
+      selected_release_id: args["selected_release_id"]
+    ]
+
+    case MusicLibrary.Records.import_from_musicbrainz_release(release_id, opts) do
+      {:ok, _record} -> :ok
+      {:error, reason} -> {:error, reason}
+    end
+  end
+
+  defp parse_datetime(nil), do: nil
+
+  defp parse_datetime(str) do
+    {:ok, datetime, _offset} = DateTime.from_iso8601(str)
+    datetime
+  end
+end