defmodule Exelli do
  use Application

  @default_elli_name :default_elli

  def start(_type, _args) do
    import Supervisor.Spec, warn: false
    Exelli.Supervisor.start_link
  end

  def elli_start(handler) do
    elli_start(handler, [])
  end

  def elli_start(handler, options) when is_atom(handler) do
    {elli_name, options} = Keyword.pop(options, :elli_name, @default_elli_name)
    options = Keyword.put(options, :callback, handler)
    defaults = [{:port, 4000}]
    options = Keyword.merge(defaults, options)
    Exelli.Supervisor.elli_start(elli_name, options)
  end

  def elli_start(handler, options) do
    handler = Enum.map(handler, &normalize_option/1)
    middleware = [
                   {:callback_args, [mods: handler]}
               ]
    elli_start(:elli_middleware, options ++ middleware)
  end

  defp normalize_option({handler, prefix}) when is_atom(handler) and is_binary(prefix) do
    {handler, [prefix: [prefix]]}
  end

  defp normalize_option({handler, prefix}) when is_atom(handler) and is_list(prefix) do
    case Keyword.has_key?(prefix, :prefix) do
      true -> {handler, prefix}
      false -> {handler, [prefix: prefix]}
    end
  end

  defp normalize_option({handler, opts}) do
    {handler, opts}
  end

  def elli_stop(elli_name \\ @default_elli_name) do
    Exelli.Supervisor.elli_stop(elli_name)
  end

  def prefix_match(path, prefix) do
    :lists.prefix(prefix, path)
  end

end