From b63b3a633a6ab2606c3a2f8017a826582cde09ca Mon Sep 17 00:00:00 2001
From: Claudio Ortolina <cloud8421@gmail.com>
Date: Mon, 2 Dec 2024 10:20:47 +0000
Subject: [PATCH] Can fetch records by a specific artist

---
 lib/music_library/records.ex                  | 23 ++++++++++++++++++-
 lib/music_library/records/artist_records.ex   | 16 +++++++++++++
 ...41202095949_create_artist_records_view.exs | 18 +++++++++++++++
 test/music_library/records_test.exs           | 23 +++++++++++++++++++
 4 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100644 lib/music_library/records/artist_records.ex
 create mode 100644 priv/repo/migrations/20241202095949_create_artist_records_view.exs

diff --git a/lib/music_library/records.ex b/lib/music_library/records.ex
index 162c0b17..2ceb2b5d 100644
--- a/lib/music_library/records.ex
+++ b/lib/music_library/records.ex
@@ -6,7 +6,7 @@ defmodule MusicLibrary.Records do
   import Ecto.Query, warn: false
   alias MusicLibrary.Repo
 
-  alias MusicLibrary.Records.{Cover, Record, SearchParser}
+  alias MusicLibrary.Records.{ArtistRecord, Cover, Record, SearchParser}
 
   def essential_fields do
     [
@@ -17,6 +17,7 @@ defmodule MusicLibrary.Records do
       :artists,
       :genres,
       :musicbrainz_id,
+      :purchased_at,
       :release_ids,
       :included_release_group_ids,
       :cover_hash,
@@ -89,6 +90,26 @@ defmodule MusicLibrary.Records do
 
   def get_record!(id), do: Repo.get!(Record, id)
 
+  def get_artist(musicbrainz_id) do
+    q =
+      from ar in ArtistRecord,
+        where: ar.musicbrainz_id == ^musicbrainz_id,
+        limit: 1,
+        select: ar.artist
+
+    Repo.one(q)
+  end
+
+  def get_artist_records(musicbrainz_id) do
+    q =
+      from r in Record,
+        join: ar in ArtistRecord,
+        on: r.id == ar.record_id and ar.musicbrainz_id == ^musicbrainz_id,
+        select: ^essential_fields()
+
+    Repo.all(q)
+  end
+
   def get_cover(id) do
     q =
       from r in Record,
diff --git a/lib/music_library/records/artist_records.ex b/lib/music_library/records/artist_records.ex
new file mode 100644
index 00000000..9e7d52df
--- /dev/null
+++ b/lib/music_library/records/artist_records.ex
@@ -0,0 +1,16 @@
+defmodule MusicLibrary.Records.ArtistRecord do
+  @moduledoc """
+  This is a lookup table that maps from an artist musicbrainz_id to a record id.
+  """
+  use Ecto.Schema
+
+  alias MusicLibrary.Records.Artist
+
+  @primary_key false
+  schema "artist_records" do
+    field :musicbrainz_id, Ecto.UUID
+    field :record_id, Ecto.UUID
+
+    embeds_one :artist, Artist
+  end
+end
diff --git a/priv/repo/migrations/20241202095949_create_artist_records_view.exs b/priv/repo/migrations/20241202095949_create_artist_records_view.exs
new file mode 100644
index 00000000..6a7d9bf0
--- /dev/null
+++ b/priv/repo/migrations/20241202095949_create_artist_records_view.exs
@@ -0,0 +1,18 @@
+defmodule MusicLibrary.Repo.Migrations.CreateArtistRecordsView do
+  use Ecto.Migration
+
+  def up do
+    execute """
+    CREATE VIEW artist_records AS
+      SELECT json_extract(json_each.value, '$.musicbrainz_id') AS musicbrainz_id, 
+      records.id AS record_id,
+      json_each.value as artist
+      FROM records, 
+      json_each(records.artists)
+    """
+  end
+
+  def down do
+    execute "DROP VIEW artist_records"
+  end
+end
diff --git a/test/music_library/records_test.exs b/test/music_library/records_test.exs
index 26732880..fdcc5ef2 100644
--- a/test/music_library/records_test.exs
+++ b/test/music_library/records_test.exs
@@ -156,6 +156,29 @@ defmodule MusicLibrary.RecordsTest do
     end
   end
 
+  describe "get_artists_records/1" do
+    test "it returns records with essential data" do
+      expected = record_fixture()
+
+      artist_musicbrainz_id = expected.artists |> hd() |> Map.get(:musicbrainz_id)
+
+      [artist_record] = Records.get_artist_records(artist_musicbrainz_id)
+
+      assert expected.id == artist_record.id
+    end
+  end
+
+  describe "get_artist/1" do
+    test "it returns records with essential data" do
+      record = record_fixture()
+      expected = record.artists |> hd()
+
+      artist = Records.get_artist(expected.musicbrainz_id)
+
+      assert expected == artist
+    end
+  end
+
   describe "get_cover/1" do
     test "it returns the record cover by id" do
       # while this test may seem redundant, it implicitely checks that ALL record fields are returned,