Display dominant colors from the db

lib/music_library/records/dominant_colors.ex

@@ -21,6 +21,17 @@ defmodule MusicLibrary.Records.DominantColors do
     end
   end
 
+  @doc """
+  Same as `extract-dominant_colors/2`, but raises an error if extraction fails.
+  """
+  @spec extract_dominant_colors!(binary(), pos_integer()) :: [String.t()] | no_return
+  def extract_dominant_colors!(image_data, num_colors \\ 5) do
+    case extract_dominant_colors(image_data, num_colors) do
+      {:ok, colors} -> colors
+      {:error, reason} -> raise "Failed to extract dominant colors: #{inspect(reason)}"
+    end
+  end
+
   defp prepare_image_for_analysis(image) do
     with {:ok, resized} <- Operation.thumbnail_image(image, 150) do
       ensure_rgb_channels(resized)

lib/music_library/records/record.ex

@@ -5,7 +5,7 @@ defmodule MusicLibrary.Records.Record do
 
   alias MusicBrainz.{Release, ReleaseGroup}
   alias MusicLibrary.Artists.Artist
-  alias MusicLibrary.Records.Cover
+  alias MusicLibrary.Records.{Cover, DominantColors}
 
   @formats [:cd, :backup, :vinyl, :blu_ray, :dvd, :multi]
   @types [:album, :ep, :live, :compilation, :single, :other]
@@ -27,6 +27,7 @@ defmodule MusicLibrary.Records.Record do
     field :selected_release_id, :string
     field :release_ids, {:array, :string}, default: []
     field :included_release_group_ids, {:array, :string}, default: []
+    field :dominant_colors, {:array, :string}, default: []
 
     embeds_many :artists, Artist, on_replace: :delete
 
@@ -112,16 +113,28 @@ defmodule MusicLibrary.Records.Record do
       :included_release_group_ids,
       :cover_url,
       :cover_data,
+      :dominant_colors,
       :purchased_at
     ])
     |> cast_embed(:artists)
     |> validate_required([:type, :title, :musicbrainz_id, :genres])
     |> unique_constraint(:musicbrainz_id, name: "records_musicbrainz_id_format_index")
     |> generate_cover_hash()
+    |> maybe_generate_dominant_colors()
     |> update_release_ids()
     |> update_included_release_group_ids()
   end
 
+  defp maybe_generate_dominant_colors(changeset) do
+    case get_change(changeset, :dominant_colors) do
+      nil ->
+        generate_dominant_colors(changeset)
+
+      _dominant_colors ->
+        changeset
+    end
+  end
+
   def add_genres(record, genres) do
     change(record, genres: genres)
   end
@@ -130,6 +143,7 @@ defmodule MusicLibrary.Records.Record do
     record
     |> change(cover_data: cover_data)
     |> generate_cover_hash()
+    |> generate_dominant_colors()
   end
 
   def add_musicbrainz_data(record, musicbrainz_data) do
@@ -155,6 +169,24 @@ defmodule MusicLibrary.Records.Record do
     end
   end
 
+  def generate_dominant_colors(%__MODULE__{cover_data: cover_data} = record) do
+    change(record, dominant_colors: DominantColors.extract_dominant_colors!(cover_data))
+  end
+
+  def generate_dominant_colors(changeset) do
+    case get_change(changeset, :cover_data) do
+      nil ->
+        changeset
+
+      cover_data ->
+        put_change(
+          changeset,
+          :dominant_colors,
+          DominantColors.extract_dominant_colors!(cover_data)
+        )
+    end
+  end
+
   defp update_release_ids(changeset) do
     case get_change(changeset, :musicbrainz_data) do
       nil ->

lib/music_library_web/live/collection_live/show.html.heex

@@ -17,7 +17,7 @@
           {@record.title}
         </h2>
         <p class="mt-2 flex items-center text-sm leading-5 text-zinc-500 dark:text-zinc-400">
-          <.record_colors colors={@dominant_colors} />
+          <.record_colors colors={@record.dominant_colors} />
           <span class="ml-1">
             {Records.Record.format_release_date(@record.release_date)} · {format_label(
               @record.format

lib/music_library_web/live/wishlist_live/show.html.heex

@@ -17,7 +17,7 @@
           {@record.title}
         </h2>
         <p class="flex items-center mt-2 text-sm leading-5 text-zinc-500 dark:text-zinc-400">
-          <.record_colors colors={@dominant_colors} />
+          <.record_colors colors={@record.dominant_colors} />
           {Records.Record.format_release_date(@record.release_date)}
           <span :if={@current_date && !Records.Record.released?(@record, @current_date)}>
             ({gettext("Unreleased")})