defmodule RailsToIanaTz do
  @moduledoc """
  Converts rails US timezones to the iana equivalent which is useful for elixir.

  ## Example

    iex> RailsToIanaTz.convert("Alaska")
    "America/Juneau""

  """

  File.stream!("tzconvert.csv")
    |> CSV.decode(separator: ?,, headers: true)
    |> Enum.each(fn(%{"IANATZ" => iana_tz, "RAILSTZ" => rails_tz}) ->
        @doc false
        def convert(unquote(rails_tz)), do: unquote(iana_tz)
    end)

  def convert(_missing), do: nil
end