defmodule Mix.Tasks.UpdateDataFiles do
  use Mix.Task

  @iso_codes_dir Application.app_dir(:iso_codes, "/priv/iso-codes")
  @gettext_dir Application.app_dir(:iso_codes, "/priv/gettext")

  def run(_args) do
    update_domain("iso_3166-1")
    update_domain("iso_3166-2")
  end

  defp update_domain(domain) do
    Path.join(@iso_codes_dir, domain)
    |> File.ls!()
    |> Enum.filter(&(String.ends_with?(&1, ".po")))
    |> Enum.each(&copy_locale_file(domain, &1))

    template_file_src = Path.join(@iso_codes_dir, domain) |> Path.join(domain <> ".pot")
    template_file_dest = Path.join(@gettext_dir, domain) |> Path.join(domain <> ".pot")
    File.cp!(template_file_src, template_file_dest)
  end

  defp copy_locale_file(domain, locale) do
    [locale, ""] = String.split(locale, ".po")

    source_file = Path.join(@iso_codes_dir, domain) |> Path.join(locale <> ".po")
    dest_file = Path.join(@gettext_dir, locale) |> Path.join(domain <> ".po")

    File.mkdir_p!(Path.join(@gettext_dir, locale))

    File.cp!(source_file, dest_file)
  end
end