frame.pony

use "buffered"

class Frame
  let _final: Bool
  let _rsv: (Bool, Bool, Bool)
  let _opcode: Opcode
  let _use_mask: Bool
  let _payload_type: U8
  let _payload_size: (U8 | U16 | U64)
  let _mask_key: (None | U32)
  let _data: Array[U8] val

  new create(final': Bool, opcode': Opcode, data': String) =>
    _final = final'
    _rsv = (false, false, false)
    _opcode = opcode'
    _use_mask = false
    _payload_type = if data'.size() <= 126 then
                      0 else if data'.size() <= 65536 then
                      1 else
                      2 end end
    _payload_size = data'.size().u64()
    _mask_key = None
    _data = data'.array()

  fun build(): Array[ByteSeq] iso^ =>
    let wb = Writer
    wb.u8(Byte.from_bits(
      if _final then 1 else 0 end,
      0,
      0,
      0,
      1,
      0,
      0,
      0
      ))
      try if _payload_type == 0 then
        let siz: U8 = _payload_size as U8
        wb.u8(siz)
      else if _payload_type == 1 then
        let siz: U16 = _payload_size as U16
        wb.u8(126)
      else
        wb.u8(127)
      end end end
    wb.done()