neiam /feedpug

defmodule FeedPug.Release do
  @moduledoc """
  Used for executing DB release tasks when run in production without Mix
  installed.
  """
  @app :feed_pug

  def migrate do
    load_app()

    for repo <- repos() do
      ensure_storage(repo)
      {:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :up, all: true))
    end
  end

  # Creates the database if it doesn't exist yet, so a fresh deploy against an
  # empty (e.g. StackGres-provisioned) Postgres server provisions its own DB.
  defp ensure_storage(repo) do
    case repo.__adapter__().storage_up(repo.config()) do
      :ok -> :ok
      {:error, :already_up} -> :ok
      {:error, reason} -> raise "database storage_up failed: #{inspect(reason)}"
    end
  end

  def rollback(repo, version) do
    load_app()
    {:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :down, to: version))
  end

  defp repos do
    Application.fetch_env!(@app, :ecto_repos)
  end

  defp load_app do
    # Many platforms require SSL when connecting to the database
    Application.ensure_all_started(:ssl)
    Application.ensure_loaded(@app)
  end
end