Improve track refresh logic

lib/last_fm.ex

@@ -2,7 +2,7 @@ defmodule LastFm do
   alias LastFm.{API, Feed, Refresh, Scrobble, Track, Worker}
   alias MusicLibrary.{BackgroundRepo, Repo}
 
-  def get_scrobbled_tracks, do: Feed.all_tracks(100)
+  def get_scrobbled_tracks(limit \\ 100), do: Feed.all_tracks(limit)
 
   def subscribe_to_feed, do: Feed.subscribe()
 

lib/last_fm/feed.ex

@@ -28,12 +28,13 @@ defmodule LastFm.Feed do
       |> Enum.map(fn t -> Map.take(t, @insertable_fields) end)
       |> Enum.map(&Map.to_list/1)
 
-    MusicLibrary.Repo.insert_all(LastFm.Track, track_params,
-      on_conflict: :nothing,
-      conflict_target: [:scrobbled_at_uts, :title]
-    )
+    {count, nil} =
+      MusicLibrary.Repo.insert_all(LastFm.Track, track_params,
+        on_conflict: :nothing,
+        conflict_target: [:scrobbled_at_uts, :title]
+      )
 
-    Phoenix.PubSub.broadcast(LastFm.PubSub, "feed:update", %{tracks: tracks})
+    Phoenix.PubSub.broadcast(LastFm.PubSub, "feed:update", %{track_count: count})
   end
 
   @spec all_tracks(non_neg_integer()) :: [LastFm.Track.t()]

lib/music_library_web/live/stats_live/index.ex

@@ -143,7 +143,13 @@ defmodule MusicLibraryWeb.StatsLive.Index do
      |> assign(scrobble_activity_mode: String.to_existing_atom(mode))}
   end
 
-  def handle_info(%{tracks: recent_tracks}, socket) do
+  def handle_info(%{track_count: 0}, socket) do
+    {:noreply, socket}
+  end
+
+  def handle_info(%{track_count: _count}, socket) do
+    recent_tracks = LastFm.get_scrobbled_tracks()
+
     {:noreply,
      socket
      |> assign_scrobble_activity(recent_tracks)}

test/last_fm/feed_test.exs

@@ -37,11 +37,15 @@ defmodule LastFm.FeedTest do
   }
 
   describe "update and broadcast" do
-    test "it stores the track and broadcasts the update" do
+    test "it stores the track and broadcasts the updated track count" do
       :ok = Feed.subscribe()
-      :ok = Feed.update([@track_two, @track_one])
 
-      assert_receive %{tracks: [@track_two, @track_one]}
+      :ok = Feed.update([@track_two, @track_one])
+      assert_receive %{track_count: 2}
+
+      # Tracks have already been inserted, count of new tracks is 0
+      :ok = Feed.update([@track_two, @track_one])
+      assert_receive %{track_count: 0}
     end
 
     test "it returns tracks in descending order of scrobble" do