defmodule Mix.Tasks.Compile.EnsureLivebookPriv do
  @moduledoc false

  use Mix.Task

  @impl true
  def run(_args) do
    # Use an absolute path, instead of relying on the current mix
    # project, so the task can be invoked by nerves_livebook.
    project_dir = Path.expand("../../..", __DIR__)
    priv_static_dir = Path.join(project_dir, "priv/static")

    # In case Livebook is used as a library as in nerves_livebook,
    # the assets.setup is not called, so we use this custom compiler
    # to invoke the task and make the assets work transparently.
    #
    # This is also used when installing escript from GitHub.
    if Mix.env() == :prod and not File.exists?(priv_static_dir) do
      Mix.shell().info("Generating priv/static")

      Mix.Task.run("bun.install", ~w"--if-missing")
      Mix.Task.run("bun", ~w"assets install")
      Mix.Task.run("bun", ~w" assets run build")
    end

    :ok
  end
end