defmodule Fluent.Assembly do
  @moduledoc """
  Module
  """
  @type t :: atom()

  @doc """
  Doc for using macro

  opts:

  * otp_app: "libfluen"
  * priv: "priv/fluent"
  * default_locale: "en-US"
  """
  defmacro __using__(opts) do
    quote location: :keep do
      @otp_app Keyword.fetch!(unquote(opts), :otp_app)
      @priv Keyword.get(unquote(opts), :priv, "fluent")
      @default_locale Keyword.get(unquote(opts), :default_locale, "en")
      @silent_errors Keyword.get(unquote(opts), :silent_errors, false)

      @spec __config__(atom()) :: any()
      def __config__(:otp_app), do: @otp_app
      def __config__(:sys), do: Application.get_env(@otp_app, __MODULE__, [])
      def __config__(:priv), do: Keyword.get(__config__(:sys), :priv, nil) || @priv
      def __config__(:default_locale), do: Keyword.get(__config__(:sys), :default_locale, nil) || @default_locale
      def __config__(:silent_errors), do: Keyword.get(__config__(:sys), :silent_errors, nil) || @silent_errors

      @spec __store__() :: Fluent.Store.t()
      def __store__ do
        Fluent.Store.get_store(__MODULE__)
      end

      def ftl(message, args \\ []) do
        locale = Fluent.get_locale(__MODULE__)
        case Fluent.Store.format_pattern(__store__(), locale, message, args) do
          {:ok, message} -> message
          _ -> case __config__(:silent_errors) do
            true -> message
            false -> raise(
              Fluent.MessageNotFound,
              msg: message,
              locale: locale,
              assembly: __MODULE__
            )
          end
        end
      end
    end
  end
end