`from_bytes` function does not work correctly for ouch

[0x00Sanket]

The built-in Message.from_bytes() method appears to search primarily in IncomingMsgClasses for message deserialization.

What OUCH calls "Incoming": OuchEnterOrder, OuchReplaceOrder, OuchCancelOrder (these are actually client → server)
What OUCH calls "Outgoing": OuchOrderAccepted, OuchOrderRejected, OuchOrderExecuted (these are actually server → client)

Thus from_bytes() fails for Ouch messages.

[SamDanielThangarajan]

@0x00Sanket That is true, When the Message.from_bytes() decodes the messageId, the messageId always assumes this to be done for the outgoing messages that are sent from server. This is the limitation today, because there is no OuchServer in this package yet, So its only client sessions that will try to decode a message.

The limitation is mainly because It is possible that IncomingMessage and Outgoing message will have the same messageId, and the fact that direction is not part of the message itself.

However if you are building a server, then we should address this.

@attrs.define(auto_attribs=True, hash=True)
class OuchMessageId(Serializable, ABC):
    indicator: int
    direction: str = 'outgoing' // Here !

    def to_bytes(self) -> tuple[int, bytes]:
        return Byte.to_bytes(self.indicator)

    @classmethod
    def from_bytes(cls, bytes_: bytes) -> tuple[int, 'OuchMessageId']:
        // This is the problem, it always constructs a messageId with direction Outgoing.
        return 1, OuchMessageId(Byte.from_bytes(bytes_)[1]) 

[0x00Sanket]

I would like to be able to convert some bytes back to the Object, after making some changes to the raw bytes. Right now, the final line of this code throws an exception. I have written a utility function for this, but having it in the library would be nice.

    def test_encode_decode_cancel_order(self):
        cancel_order = OuchCancelOrder()
        cancel_order.orderToken = 12345678

        _length, message_bytes = cancel_order.to_bytes()

        assert message_bytes[0] == 88  # indicator for OuchCancelOrder
        decoded_message = Message.from_bytes(message_bytes)