from .packet import Packet
import random


class EnumQuery:
    LEAD = 0x00
    COMMAND = 0x02
    NO_APPLICATION_GUID = 0x02
    HAS_APPLICATION_GUID = 0x01

    def __init__(self, packet=None):
        self.Lead = EnumQuery.LEAD
        self.Command = EnumQuery.COMMAND
        self.Payload = random.getrandbits(16)
        self.Type = None
        self.ApplicationGUID = None
        self.ApplicationPayload = None

        if packet:
            self.parse(packet)

    def parse(self, packet):
        self.Lead = EnumQuery.LEAD
        self.Command = EnumQuery.COMMAND
        self.Payload = packet.getShort()
        self.Type = packet.getByte()
        if self.Type == EnumQuery.HAS_APPLICATION_GUID:
            self.ApplicationGUID = packet.getBytes(16)
            self.ApplicationPayload = packet.read()
        elif self.Type == EnumQuery.NO_APPLICATION_GUID:
            self.ApplicationPayload = packet.read()
        else:
            raise Exception("EnumQuery type was incorrect: "+self.Type)

    def to_packet(self):
        packet = Packet()
        packet.putByte(EnumQuery.LEAD)
        packet.putByte(EnumQuery.COMMAND)
        packet.putShort(self.Payload)
        if self.ApplicationGUID:
            packet.putByte(EnumQuery.HAS_APPLICATION_GUID)
            packet.putBytes(self.ApplicationGUID)
        else:
            packet.putByte(EnumQuery.NO_APPLICATION_GUID)

        if self.ApplicationPayload:
            packet.putBytes(self.ApplicationPayload)

        return packet