[Enhancement] Capture playlist_index for use with output templates (#315)

* Started capturing playlist_index on indexing pass

* Added playlist_index as a media item field

* Added playlist index to output variable templates

* Improved the way playlist_indexes are rejected on update

* Updated docs

* Undid unneeded changes

lib/pinchflat/downloading/download_option_builder.ex

@@ -203,6 +203,7 @@ defmodule Pinchflat.Downloading.DownloadOptionBuilder do
       "source_collection_id" => source.collection_id,
       "source_collection_name" => source.collection_name,
       "source_collection_type" => to_string(source.collection_type),
+      "media_playlist_index" => to_string(media_item_with_preloads.playlist_index),
       "media_upload_date_index" =>
         media_item_with_preloads.upload_date_index
         |> to_string()

lib/pinchflat/media/media.ex

@@ -142,12 +142,17 @@ defmodule Pinchflat.Media do
   """
   def create_media_item_from_backend_attrs(source, media_attrs_struct) do
     attrs = Map.merge(%{source_id: source.id}, Map.from_struct(media_attrs_struct))
+    # Some fields should only be set on insert and not on update.
+    fields_to_drop_on_update = [:playlist_index]
 
     %MediaItem{}
     |> MediaItem.changeset(attrs)
     |> Repo.insert(
       on_conflict: [
-        set: Map.to_list(attrs)
+        set:
+          attrs
+          |> Map.drop(fields_to_drop_on_update)
+          |> Map.to_list()
       ],
       conflict_target: [:source_id, :media_id]
     )

lib/pinchflat/media/media_item.ex

@@ -18,6 +18,8 @@ defmodule Pinchflat.Media.MediaItem do
   alias Pinchflat.Media.MediaItemsSearchIndex
 
   @allowed_fields [
+    # these fields are only captured on index
+    :playlist_index,
     # these fields are captured on indexing (and again on download)
     :title,
     :media_id,
@@ -72,6 +74,7 @@ defmodule Pinchflat.Media.MediaItem do
     field :uploaded_at, :utc_datetime
     field :upload_date_index, :integer, default: 0
     field :duration_seconds, :integer
+    field :playlist_index, :integer, default: 0
 
     field :media_filepath, :string
     field :media_size_bytes, :integer

lib/pinchflat/yt_dlp/media.ex

@@ -22,7 +22,8 @@ defmodule Pinchflat.YtDlp.Media do
     :livestream,
     :short_form_content,
     :uploaded_at,
-    :duration_seconds
+    :duration_seconds,
+    :playlist_index
   ]
 
   alias __MODULE__
@@ -63,7 +64,7 @@ defmodule Pinchflat.YtDlp.Media do
   @doc """
   Returns a map representing the media at the given URL.
 
-  Returns {:ok, [map()]} | {:error, any, ...}.
+  Returns {:ok, %Media{}} | {:error, any, ...}.
   """
   def get_media_attributes(url) do
     runner = Application.get_env(:pinchflat, :yt_dlp_runner)
@@ -84,9 +85,11 @@ defmodule Pinchflat.YtDlp.Media do
 
   @doc """
   Returns the output template for yt-dlp's indexing command.
+
+  NOTE: playlist_index is really only useful for playlists that will never change their order.
   """
   def indexing_output_template do
-    "%(.{id,title,was_live,webpage_url,description,aspect_ratio,duration,upload_date,timestamp})j"
+    "%(.{id,title,was_live,webpage_url,description,aspect_ratio,duration,upload_date,timestamp,playlist_index})j"
   end
 
   @doc """
@@ -104,7 +107,8 @@ defmodule Pinchflat.YtDlp.Media do
       livestream: !!response["was_live"],
       duration_seconds: response["duration"] && round(response["duration"]),
       short_form_content: response["webpage_url"] && short_form_content?(response),
-      uploaded_at: response["upload_date"] && parse_uploaded_at(response)
+      uploaded_at: response["upload_date"] && parse_uploaded_at(response),
+      playlist_index: response["playlist_index"] || 0
     }
   end
 

lib/pinchflat_web/controllers/media_profiles/media_profile_html.ex

@@ -68,7 +68,9 @@ defmodule PinchflatWeb.MediaProfiles.MediaProfileHTML do
       season_from_date: "alias for upload_year",
       season_episode_from_date: "the upload date formatted as sYYYYeMMDD",
       season_episode_index_from_date:
-        "the upload date formatted as sYYYYeMMDDII where II is an index to prevent date collisions"
+        "the upload date formatted as sYYYYeMMDDII where II is an index to prevent date collisions",
+      media_playlist_index:
+        "the place of the media item in the playlist. Do not use with channels. May not work if the playlist is updated"
     }
   end
 

priv/repo/migrations/20240715212133_add_playlist_index_to_media_items.exs

@@ -0,0 +1,9 @@
+defmodule Pinchflat.Repo.Migrations.AddPlaylistIndexToMediaItems do
+  use Ecto.Migration
+
+  def change do
+    alter table(:media_items) do
+      add :playlist_index, :integer, null: false, default: 0
+    end
+  end
+end

test/pinchflat/media_test.exs

@@ -689,7 +689,24 @@ defmodule Pinchflat.MediaTest do
       assert {:ok, %MediaItem{} = media_item_2} = Media.create_media_item_from_backend_attrs(source, different_attrs)
 
       assert media_item_1.id == media_item_2.id
-      assert media_item_2.title == different_attrs.title
+      assert Repo.reload(media_item_2).title == different_attrs.title
+    end
+
+    test "doesn't update fields like playlist_index" do
+      source = source_fixture()
+
+      media_attrs =
+        media_attributes_return_fixture()
+        |> Phoenix.json_library().decode!()
+        |> Map.put("playlist_index", 1)
+        |> YtDlpMedia.response_to_struct()
+
+      different_attrs = %YtDlpMedia{media_attrs | playlist_index: 9999}
+
+      assert {:ok, %MediaItem{} = _media_item_1} = Media.create_media_item_from_backend_attrs(source, media_attrs)
+      assert {:ok, %MediaItem{} = media_item_2} = Media.create_media_item_from_backend_attrs(source, different_attrs)
+
+      assert Repo.reload(media_item_2).playlist_index == media_attrs.playlist_index
     end
   end
 

test/pinchflat/yt_dlp/media_test.exs

@@ -110,8 +110,10 @@ defmodule Pinchflat.YtDlp.MediaTest do
 
   describe "indexing_output_template/0" do
     test "contains all the greatest hits" do
-      assert "%(.{id,title,was_live,webpage_url,description,aspect_ratio,duration,upload_date,timestamp})j" ==
-               Media.indexing_output_template()
+      attrs = ~w(id title was_live webpage_url description aspect_ratio duration upload_date timestamp playlist_index)a
+      formatted_attrs = "%(.{#{Enum.join(attrs, ",")}})j"
+
+      assert formatted_attrs == Media.indexing_output_template()
     end
   end
 
@@ -126,7 +128,8 @@ defmodule Pinchflat.YtDlp.MediaTest do
         "aspect_ratio" => 1.0,
         "duration" => 60,
         "upload_date" => "20210101",
-        "timestamp" => 1_600_000_000
+        "timestamp" => 1_600_000_000,
+        "playlist_index" => 1
       }
 
       assert %Media{
@@ -137,7 +140,8 @@ defmodule Pinchflat.YtDlp.MediaTest do
                livestream: false,
                short_form_content: false,
                uploaded_at: ~U[2020-09-13 12:26:40Z],
-               duration_seconds: 60
+               duration_seconds: 60,
+               playlist_index: 1
              } == Media.response_to_struct(response)
     end
 
@@ -217,6 +221,17 @@ defmodule Pinchflat.YtDlp.MediaTest do
 
       assert %Media{livestream: false} = Media.response_to_struct(response)
     end
+
+    test "doesn't blow up if playlist_index is missing" do
+      response = %{
+        "webpage_url" => "https://www.youtube.com/watch?v=TiZPUDkDYbk",
+        "aspect_ratio" => 1.0,
+        "duration" => nil,
+        "upload_date" => "20210101"
+      }
+
+      assert %Media{playlist_index: 0} = Media.response_to_struct(response)
+    end
   end
 
   describe "response_to_struct/1 when testing uploaded_at" do