from datetime import datetime, date

USHRT_MAX = 65535


CMD_CONNECT = 1000
CMD_EXIT = 1001
CMD_ENABLEDEVICE = 1002
CMD_DISABLEDEVICE = 1003

CMD_ACK_OK = 2000
CMD_ACK_ERROR = 2001
CMD_ACK_DATA = 2002

CMD_PREPARE_DATA = 1500
CMD_DATA = 1501

CMD_USERTEMP_RRQ = 9
CMD_ATTLOG_RRQ = 13
CMD_CLEAR_DATA = 14
CMD_CLEAR_ATTLOG = 15

CMD_WRITE_LCD = 66

CMD_GET_TIME  = 201
CMD_SET_TIME  = 202

CMD_VERSION = 1100
CMD_DEVICE = 11

CMD_CLEAR_ADMIN = 20
CMD_SET_USER = 8

LEVEL_USER = 0
LEVEL_ADMIN = 14

def encode_time(t):
    """Encode a timestamp send at the timeclock

    copied from zkemsdk.c - EncodeTime"""
    d = ( (t.year % 100) * 12 * 31 + ((t.month - 1) * 31) + t.day - 1) *\
         (24 * 60 * 60) + (t.hour * 60 + t.minute) * 60 + t.second

    return d


def decode_time(t):
    """Decode a timestamp retrieved from the timeclock

    copied from zkemsdk.c - DecodeTime"""
    second = t % 60
    t = t / 60

    minute = t % 60
    t = t / 60

    hour = t % 24
    t = t / 24

    day = t % 31+1
    t = t / 31

    month = t % 12+1
    t = t / 12

    year = t + 2000

    d = datetime(int(year), int(month), int(day), int(hour), int(minute), int(second))

    return d