[Enhancement] Added ability to detect when files have been deleted (#399)

* Added function for updating a media item's filepaths on-disk

* Added placeholder action to source page

* Turned the file sync into a job and properly hooked it up to the controller

lib/pinchflat/downloading/media_download_worker.ex

@@ -12,7 +12,7 @@ defmodule Pinchflat.Downloading.MediaDownloadWorker do
   alias Pinchflat.Tasks
   alias Pinchflat.Repo
   alias Pinchflat.Media
-  alias Pinchflat.Media.FileDeletion
+  alias Pinchflat.Media.FileSyncing
   alias Pinchflat.Downloading.MediaDownloader
 
   alias Pinchflat.Lifecycle.UserScripts.CommandRunner, as: UserScriptRunner
@@ -86,7 +86,7 @@ defmodule Pinchflat.Downloading.MediaDownloadWorker do
             media_redownloaded_at: get_redownloaded_at(is_quality_upgrade)
           })
 
-        :ok = FileDeletion.delete_outdated_files(media_item, updated_media_item)
+        :ok = FileSyncing.delete_outdated_files(media_item, updated_media_item)
         run_user_script(:media_downloaded, updated_media_item)
 
         :ok

lib/pinchflat/media/file_syncing.ex

@@ -1,8 +1,9 @@
-defmodule Pinchflat.Media.FileDeletion do
+defmodule Pinchflat.Media.FileSyncing do
   @moduledoc """
-  Functions for deleting files that are no longer needed by media items.
+  Functions for ensuring file state is accurately reflected in the database.
   """
 
+  alias Pinchflat.Media
   alias Pinchflat.Utils.MapUtils
   alias Pinchflat.Media.MediaItem
   alias Pinchflat.Utils.FilesystemUtils, as: FSUtils
@@ -34,6 +35,22 @@ defmodule Pinchflat.Media.FileDeletion do
     :ok
   end
 
+  @doc """
+  Nillifies any media item filepaths that don't exist on disk for a list of media items
+
+  returns [%MediaItem{}]
+  """
+  def sync_file_presence_on_disk(media_items) do
+    Enum.map(media_items, fn media_item ->
+      new_attributes = sync_media_item_files(media_item)
+      # Doing this one-by-one instead of batching since this process
+      # can take time and a batch could let MediaItem state get out of sync
+      {:ok, updated_media_item} = Media.update_media_item(media_item, new_attributes)
+
+      updated_media_item
+    end)
+  end
+
   defp handle_file_deletion(old_attributes, new_attributes) do
     # The logic:
     #   - A file should only be deleted if it exists and the new file is different
@@ -51,4 +68,26 @@ defmodule Pinchflat.Media.FileDeletion do
       end
     end)
   end
+
+  defp sync_media_item_files(media_item) do
+    non_subtitle_keys = MediaItem.filepath_attributes() -- [:subtitle_filepaths]
+    subtitle_keys = MapUtils.from_nested_list(media_item.subtitle_filepaths)
+    non_subtitles = Map.take(media_item, non_subtitle_keys)
+
+    # This one is checking for the negative (ie: only update if the file doesn't exist)
+    new_non_subtitle_attrs =
+      Enum.reduce(non_subtitles, %{}, fn {key, filepath}, acc ->
+        if filepath && File.exists?(filepath), do: acc, else: Map.put(acc, key, nil)
+      end)
+
+    # This one is checking for the positive (ie: only update if the file exists)
+    # This is because subtitles, being an array type in the DB, are most easily updated
+    # by a full replacement rather than finding the actual diff
+    new_subtitle_attrs =
+      Enum.reduce(subtitle_keys, [], fn {key, filepath}, acc ->
+        if filepath && File.exists?(filepath), do: acc ++ [[key, filepath]], else: acc
+      end)
+
+    Map.put(new_non_subtitle_attrs, :subtitle_filepaths, new_subtitle_attrs)
+  end
 end

lib/pinchflat/media/file_syncing_worker.ex

@@ -0,0 +1,38 @@
+defmodule Pinchflat.Media.FileSyncingWorker do
+  @moduledoc false
+
+  use Oban.Worker,
+    queue: :local_data,
+    tags: ["sources", "local_data"]
+
+  alias __MODULE__
+  alias Pinchflat.Repo
+  alias Pinchflat.Tasks
+  alias Pinchflat.Sources
+  alias Pinchflat.Media.FileSyncing
+
+  @doc """
+  Starts the source file syncing worker.
+
+  Returns {:ok, %Task{}} | {:error, %Ecto.Changeset{}}
+  """
+  def kickoff_with_task(source, opts \\ []) do
+    %{id: source.id}
+    |> FileSyncingWorker.new(opts)
+    |> Tasks.create_job_with_task(source)
+  end
+
+  @doc """
+  Deletes a profile and optionally deletes its files
+
+  Returns :ok
+  """
+  @impl Oban.Worker
+  def perform(%Oban.Job{args: %{"id" => source_id}}) do
+    source = Repo.preload(Sources.get_source!(source_id), :media_items)
+
+    FileSyncing.sync_file_presence_on_disk(source.media_items)
+
+    :ok
+  end
+end