defmodule Postgrex.Extensions.Float4 do
  @moduledoc false
  import Postgrex.BinaryUtils, warn: false
  use Postgrex.BinaryExtension, send: "float4send"

  def encode(_) do
    quote location: :keep do
      n when is_number(n) ->
        <<4::int32, n::float32>>
      :NaN ->
        <<4::int32, 0::1, 255, 1::1, 0::22>>
      :inf ->
        <<4::int32, 0::1, 255, 0::23>>
      :"-inf" ->
        <<4::int32, 1::1, 255, 0::23>>
      other ->
        raise DBConnection.EncodeError, Postgrex.Utils.encode_msg(other, "a float")
    end
  end

  def decode(_) do
    quote location: :keep do
      <<4::int32, 0::1, 255, 0::23>> -> :inf
      <<4::int32, 1::1, 255, 0::23>> -> :"-inf"
      <<4::int32, _::1, 255, _::23>> -> :NaN
      <<4::int32, float::float32>>   -> float
    end
  end
end