akkoma/priv/repo/migrations/20201005132900_transparency_exclusions_string_to_tuple.exs

defmodule Pleroma.Repo.Migrations.TransparencyExclusionsStringToTuple do
  use Ecto.Migration

  alias Pleroma.ConfigDB

  def up,
    do:
      ConfigDB.get_by_params(%{group: :pleroma, key: :mrf})
      |> update_transparency_exclusions_instances_to_tuples

  def down,
    do:
      ConfigDB.get_by_params(%{group: :pleroma, key: :mrf})
      |> update_transparency_exclusions_instances_to_strings

  defp update_transparency_exclusions_instances_to_tuples(%{value: settings}) do
    settings |> List.keyfind(:transparency_exclusions, 0) |> update_to_tuples
  end

  defp update_transparency_exclusions_instances_to_tuples(nil), do: {:ok, nil}

  defp update_to_tuples({:transparency_exclusions, instance_list}) do
    new_value =
      instance_list
      |> Enum.map(fn
        {v, r} -> {v, r}
        v -> {v, ""}
      end)

    ConfigDB.update_or_create(%{
      group: :pleroma,
      key: :mrf,
      value: [transparency_exclusions: new_value]
    })
  end

  defp update_to_tuples(nil), do: {:ok, nil}

  defp update_transparency_exclusions_instances_to_strings(%{value: settings}) do
    settings |> List.keyfind(:transparency_exclusions, 0) |> update_to_strings
  end

  defp update_transparency_exclusions_instances_to_strings(nil), do: {:ok, nil}

  defp update_to_strings({:transparency_exclusions, instance_list}) do
    new_value =
      instance_list
      |> Enum.map(fn
        {v, _} -> v
        v -> v
      end)

    ConfigDB.update_or_create(%{
      group: :pleroma,
      key: :mrf,
      value: [transparency_exclusions: new_value]
    })
  end

  defp update_to_strings(nil), do: {:ok, nil}
end