defmodule Pathex.Builder.SimpleSetter do

  @moduledoc """
  Setter which simply sets new value in given path
  """

  import Pathex.Builder.Setter
  @behaviour Pathex.Builder.Setter

  @first_arg {:first_arg, [], Elixir}
  @initial {:value_to_set, [], Elixir}

  def build(combination) do
    combination
    |> Enum.reverse()
    |> Enum.reduce(initial(), &reduce_into/2)
    |> wrap_to_code(@first_arg, @initial)
  end

  defp reduce_into(path_items, acc) do
    setters = Enum.flat_map(path_items, & create_setter(&1, acc))
    {:case, [], [[do: setters ++ fallback()]]}
  end

  defp initial do
    quote do
      (fn _ -> unquote(@initial) end).()
    end
  end

end