defmodule Cldr.Config.Dependents do
  @moduledoc false

  defp known_providers do
    %{
      Cldr.Number => {Cldr.Number.Backend, :define_number_modules},
      Cldr.Currency => {Cldr.Currency.Backend, :define_currency_module},
      Cldr.DateTime => {Cldr.DateTime.Backend, :define_date_time_modules},
      Cldr.List => {Cldr.List.Backend, :define_list_module},
      Cldr.Unit => {Cldr.Unit.Backend, :define_unit_module},
      Cldr.Territory => {Cldr.Territory.Backend, :define_territory_module},
      Cldr.Calendar => {Cldr.Calendar.Backend, :define_calendar_module}
    }
  end

  # Cldr.Currency is automatically generated from
  # Cldr.Numbers so we shouldn't auto generate here
  # Eventually we should remove the idea of known
  # provider modules
  defp known_provider_modules do
    known_providers()
    |> Map.keys()
    |> List.delete(Cldr.Currency)
  end

  @provider_fun_name :cldr_backend_provider

  # For compatibility with the releases that don't configure
  # Reconsider this.
  def cldr_provider_modules(%Cldr.Config{providers: nil, backend: backend} = config) do
    if !config.supress_warnings do
      require Logger

      Logger.warn(
        "#{inspect(backend)}: No Cldr provider modules were configured. " <>
          "Attempting to configure known Cldr providers."
      )
    end

    cldr_provider_modules(%{config | providers: known_provider_modules()})
  end

  def cldr_provider_modules(%Cldr.Config{providers: providers} = config)
      when is_list(providers) do
    for provider_module <- providers do
      if mf = Map.get(known_providers(), provider_module) do
        {m, f} = mf
        {m, f, [config]}
      else
        {provider_module, @provider_fun_name, [config]}
      end
    end
  end

  def cldr_provider_modules(%Cldr.Config{providers: providers, backend: backend}) do
    raise ArgumentError,
          "The config key :providers should be a list of " <>
            "module names that are called at compile time. " <>
            "Found #{inspect(providers)} in backend #{inspect(backend)}"
  end
end