Refactor modules into contexts (#78)

* [WIP] break out a few contexts, start refactoring fast index modules

* [WIP] more contexts, this time around slow indexing and downloads

* [WIP] got all tests passing

* [WIP] Added moduledocs

* Built a genserver to rename old jobs on boot

* Added a module naming check; moved things around

* Fixed specs

lib/pinchflat/boot/pre_job_startup_tasks.ex

@@ -0,0 +1,73 @@
+defmodule Pinchflat.Boot.PreJobStartupTasks do
+  @moduledoc """
+  This module is responsible for running startup tasks on app boot
+  BEFORE the job runner has initiallized.
+
+  It's a GenServer because that plays REALLY nicely with the existing
+  Phoenix supervision tree.
+  """
+
+  # restart: :temporary means that this process will never be restarted (ie: will run once and then die)
+  use GenServer, restart: :temporary
+  import Ecto.Query, warn: false
+  require Logger
+
+  alias Pinchflat.Repo
+  alias Pinchflat.Settings
+
+  def start_link(opts \\ []) do
+    GenServer.start_link(__MODULE__, %{}, opts)
+  end
+
+  @doc """
+  Runs application startup tasks.
+
+  Any code defined here will run every time the application starts. You must
+  make sure that the code is idempotent and safe to run multiple times.
+
+  This is a good place to set up default settings, create initial records, stuff like that.
+  Should be fast - anything with the potential to be slow should be kicked off as a job instead.
+  """
+  @impl true
+  def init(state) do
+    apply_default_settings()
+    rename_old_job_workers()
+
+    {:ok, state}
+  end
+
+  defp apply_default_settings do
+    Settings.fetch!(:onboarding, true)
+    Settings.fetch!(:pro_enabled, false)
+  end
+
+  # As part of a large refactor, I ended up moving a bunch of workers around. This
+  # is a problem because the workers are stored in the database and the runner
+  # will try to run the OLD jobs. This is also why these tasks run before the job
+  # runner starts up.
+  #
+  # Can be removed after a few months (created: 2024-03-12)
+  defp rename_old_job_workers do
+    # [ [old_name, new_name], ...]
+    rename_map = [
+      ["Pinchflat.Workers.MediaIndexingWorker", "Pinchflat.FastIndexing.MediaIndexingWorker"],
+      ["Pinchflat.Workers.MediaDownloadWorker", "Pinchflat.Downloading.MediaDownloadWorker"],
+      ["Pinchflat.Workers.FilesystemDataWorker", "Pinchflat.Filesystem.FilesystemDataWorker"],
+      ["Pinchflat.Workers.FastIndexingWorker", "Pinchflat.FastIndexing.FastIndexingWorker"],
+      ["Pinchflat.Workers.MediaCollectionIndexingWorker", "Pinchflat.SlowIndexing.MediaCollectionIndexingWorker"],
+      ["Pinchflat.Workers.DataBackfillWorker", "Pinchflat.Boot.DataBackfillWorker"]
+    ]
+
+    jobs_renamed =
+      Enum.reduce(rename_map, 0, fn [old_name, new_name], acc ->
+        {count, _} =
+          Oban.Job
+          |> where(worker: ^old_name)
+          |> Repo.update_all(set: [worker: new_name])
+
+        acc + count
+      end)
+
+    Logger.info("Renamed #{jobs_renamed} old job workers")
+  end
+end