--Wraps all I/O using rot13 encoding.

print("Running rot13, super is", super)

local rot13_c = function (c)

  local a = string.byte "a"
  local z = string.byte "z"
  local A = string.byte "A"
  local Z = string.byte "Z"

  local byte = string.byte(c)
  if byte >= a and byte <= z then
    return string.char(((byte - a) + 13) % 26 + a)
  elseif byte >= A and byte <= Z then
    return string.char(((byte - A) + 13) % 26 + A)
  else
    return c
  end
end

local rot13 = function (s)
  return (string.gsub(s, ".", function (c) return rot13_c(c) end))
end

return {
  recv = function (self)
    local line, err = super:recv()
    if line == nil then
      return line, err
    end
    return rot13(line)
  end,

  send = function (self, data)
    return super:send(rot13(data))
  end,
}