from .packet import Packet
import random


class CFrame:
    PACKET_COMMAND_FRAME = 0x80
    PACKET_COMMAND_POLL = 0x08
    FRAME_EXOPCODE_CONNECT = 0x01
    FRAME_EXOPCODE_CONNECTED = 0x02
    FRAME_EXOPCODE_CONNECTED_SIGNED = 0x03
    FRAME_EXOPCODE_HARD_DISCONNECT = 0x04
    FRAME_EXOPCODE_SACK = 0x06

    SACK_FLAGS_RESPONSE = 0x01
    SACK_FLAGS_SACK_MASK1 = 0x02
    SACK_FLAGS_SACK_MASK2 = 0x04
    SACK_FLAGS_SEND_MASK1 = 0x08
    SACK_FLAGS_SEND_MASK2 = 0x10

    def __init__(self, packet=None):
        self.Command = CFrame.PACKET_COMMAND_FRAME | CFrame.PACKET_COMMAND_POLL
        self.ExtOpCode = CFrame.FRAME_EXOPCODE_CONNECT
        self.MsgID = 0
        self.RspId = 0
        self.Flags = 1
        self.Retry = 0
        self.NSeq = 0
        self.NRecv = 0
        self.CurrentProtocolVersion = 0x00010006
        self.SessID = random.getrandbits(32)
        self.Timestamp = random.getrandbits(32)

        if packet:
            self.parse(packet)

    def parse(self, packet):
        packet.seek(0)
        self.Command = packet.getByte()
        self.ExtOpCode = packet.getByte()
        if self.ExtOpCode == CFrame.FRAME_EXOPCODE_CONNECTED_SIGNED:
            raise Exception("CONNECTED_SIGNED is not implemented")
        if self.ExtOpCode == CFrame.FRAME_EXOPCODE_SACK:
            self.Flags = packet.getByte()
            self.Retry = packet.getByte()
            self.NSeq = packet.getByte()
            self.NRecv = packet.getByte()
            packet.getByte() # padding
            packet.getByte() # padding
            self.Timestamp = packet.getULong()
        else:
            self.MsgID = packet.getByte()
            self.RspId = packet.getByte()
            self.CurrentProtocolVersion = packet.getLong()
            self.SessID = packet.getLong()
            self.Timestamp = packet.getULong()

    def to_packet(self):
        packet = Packet()
        packet.putByte(self.Command)
        packet.putByte(self.ExtOpCode)
        if self.ExtOpCode == CFrame.FRAME_EXOPCODE_SACK:
            packet.putByte(self.Flags)
            packet.putByte(self.Retry)
            packet.putByte(self.NSeq)
            packet.putByte(self.NRecv)
            packet.putShort(0) # padding
            packet.putULong(self.Timestamp)
        else:
            packet.putByte(self.MsgID)
            packet.putByte(self.RspId)
            packet.putLong(self.CurrentProtocolVersion)
            packet.putLong(self.SessID)
            packet.putULong(self.Timestamp)
        return packet