defmodule Openflow.Features.Reply do
  defstruct(
    version:        4,
    xid:            0,
    datapath_id:   "",
    n_buffers:      0,
    n_tables:       0,
    aux_id:         0,
    capabilities:   []
  )

  alias __MODULE__

  def ofp_type, do: 6

  def read(<<datapath_id::64-bits, n_buf::32, n_tab::8,
    aux_id::8, _pad::16, caps_int::32, _rsv::32>>) do
    dpid = Openflow.Utils.to_hex_string(datapath_id)
    flags = Openflow.Enums.int_to_flags(caps_int, :switch_capabilities)
    %Reply{
      datapath_id: dpid,
      n_buffers: n_buf,
      n_tables: n_tab,
      aux_id: aux_id,
      capabilities: flags
    }
  end

  def to_binary(%Reply{
        datapath_id: datapath_id,
        n_buffers: n_buf,
        n_tables: n_tab,
        aux_id: aux_id,
        capabilities: flags}) do
    dpid_int = String.to_integer(datapath_id, 16)
    flags_int = Openflow.Enums.flags_to_int(flags, :switch_capabilities)
    <<dpid_int::64, n_buf::32, n_tab::8, aux_id::8, 0::16, flags_int::32, 0::32>>
  end
end