Add function to backfill missing data in scrobbled tracks

lib/music_library/artists.ex

@@ -31,6 +31,16 @@ defmodule MusicLibrary.Artists do
     end
   end
 
+  def name_id_pairs(names) do
+    q =
+      from ar in ArtistRecord,
+        distinct: true,
+        where: fragment("artist ->> '$.name'") in ^names,
+        select: {fragment("artist ->> '$.name'"), ar.musicbrainz_id}
+
+    Repo.all(q)
+  end
+
   def get_all_artist_ids do
     q = from ar in ArtistRecord, distinct: true, select: ar.musicbrainz_id
 

lib/music_library/scrobble_activity/backfill.ex

@@ -0,0 +1,36 @@
+defmodule MusicLibrary.ScrobbleActivity.Backfill do
+  alias MusicLibrary.Artists
+  alias MusicLibrary.Repo
+
+  @allowed_artists [
+    "IQ",
+    "Riverside",
+    "Airbag",
+    "Arena",
+    "Fish",
+    "Marillion",
+    "Porcupine Tree",
+    "Steven Wilson",
+    "Gazpacho",
+    "Sylvan",
+    "Dream Theater",
+    "Pink Floyd",
+    "Muse",
+    "Opeth"
+  ]
+
+  def fill_missing_artist_ids do
+    name_id_pairs = Artists.name_id_pairs(@allowed_artists)
+
+    Enum.each(name_id_pairs, fn {name, id} ->
+      Repo.query(
+        """
+        UPDATE scrobbled_tracks
+        SET artist = json_set(artist, '$.musicbrainz_id', ?)
+        WHERE artist ->> '$.name' == ?;
+        """,
+        [id, name]
+      )
+    end)
+  end
+end