# -*- coding: utf-8 -*-
import sys
#from builtins import str
from datetime import datetime
from socket import AF_INET, SOCK_DGRAM, SOCK_STREAM, socket, timeout
from struct import pack, unpack
import codecs

from zk import const
from zk.attendance import Attendance
from zk.exception import ZKErrorResponse, ZKNetworkError
from zk.user import User
from zk.finger import Finger

def safe_cast(val, to_type, default=None):
    #https://stackoverflow.com/questions/6330071/safe-casting-in-python
    try:
        return to_type(val)
    except (ValueError, TypeError):
        return default


def make_commkey(key, session_id, ticks=50):
    """take a password and session_id and scramble them to send to the time
    clock.
    copied from commpro.c - MakeKey"""
    key = int(key)
    session_id = int(session_id)
    k = 0
    for i in range(32):
        if (key & (1 << i)):
            k = (k << 1 | 1)
        else:
            k = k << 1
    k += session_id

    k = pack(b'I', k)
    k = unpack(b'BBBB', k)
    k = pack(
        b'BBBB',
        k[0] ^ ord('Z'),
        k[1] ^ ord('K'),
        k[2] ^ ord('S'),
        k[3] ^ ord('O'))
    k = unpack(b'HH', k)
    k = pack(b'HH', k[1], k[0])

    B = 0xff & ticks
    k = unpack(b'BBBB', k)
    k = pack(
        b'BBBB',
        k[0] ^ B,
        k[1] ^ B,
        B,
        k[3] ^ B)
    return k

class ZK_helper(object):
    """ helper class """
    def __init__(self, ip, port=4370):
        self.address = (ip, port)
        self.ip = ip
        self.port = port
        #self.timeout = timeout
        #self.password = password # passint
        #self.firmware = int(firmware) #TODO check minor version?
        #self.tcp = tcp

    def test_ping(self):
        """
        Returns True if host responds to a ping request
        """
        import subprocess, platform
        # Ping parameters as function of OS
        ping_str = "-n 1" if  platform.system().lower()=="windows" else "-c 1 -W 5"
        args = "ping " + " " + ping_str + " " + self.ip
        need_sh = False if  platform.system().lower()=="windows" else True
        # Ping
        return subprocess.call(args,
                            stdout=subprocess.PIPE,
                            stderr=subprocess.PIPE,
                            shell=need_sh) == 0

    def test_tcp(self):
        self.client = socket(AF_INET, SOCK_STREAM)
        self.client.settimeout(10) # fixed test
        res = self.client.connect_ex(self.address)
        self.client.close()
        return res

    def test_udp(self): # WIP:
        self.client = socket(AF_INET, SOCK_DGRAM)
        self.client.settimeout(10) # fixed test

class ZK(object):
    """ Clase ZK """
    def __init__(self, ip, port=4370, timeout=60, password=0, force_udp=False, ommit_ping=False, verbose=False, encoding='UTF-8'):
        """ initialize instance """
        self.is_connect = False
        self.is_enabled = True #let's asume
        self.helper = ZK_helper(ip, port)
        self.__address = (ip, port)
        self.__sock = socket(AF_INET, SOCK_DGRAM)
        self.__sock.settimeout(timeout)
        self.__timeout = timeout
        self.__password = password # passint
        #self.firmware = int(firmware) #dummy
        self.force_udp = force_udp
        self.ommit_ping = ommit_ping
        self.verbose = verbose
        self.encoding = encoding
        User.encoding = encoding
        self.tcp = False
        self.users = 0
        self.fingers = 0
        self.records = 0
        self.dummy = 0
        self.cards = 0
        self.fingers_cap = 0
        self.users_cap = 0
        self.rec_cap = 0
        self.faces = 0
        self.faces_cap = 0
        self.fingers_av = 0
        self.users_av = 0
        self.rec_av = 0
        self.next_uid = 1
        self.next_user_id='1'
        self.user_packet_size = 28 # default zk6
        self.end_live_capture = False
        self.__session_id = 0
        self.__reply_id = const.USHRT_MAX-1
        self.__data_recv = None
        self.__data = None

    def __nonzero__(self):
        """ for boolean test"""
        return self.is_connect

    def __create_socket(self):
        """ based on self.tcp"""
        if self.tcp:
            self.__sock = socket(AF_INET, SOCK_STREAM)
            self.__sock.settimeout(self.__timeout)
            self.__sock.connect_ex(self.__address)
        else:
            self.__sock = socket(AF_INET, SOCK_DGRAM)
            self.__sock.settimeout(self.__timeout)

    def __create_tcp_top(self, packet):
        """ witch the complete packet set top header """
        length = len(packet)
        top = pack('<HHI', const.MACHINE_PREPARE_DATA_1, const.MACHINE_PREPARE_DATA_2, length)
        return top + packet

    def __create_header(self, command, command_string, session_id, reply_id):
        '''
        Puts a the parts that make up a packet together and packs them into a byte string

        MODIFIED now, without initial checksum
        '''
        #checksum = 0 always? for calculating
        buf = pack('<4H', command, 0, session_id, reply_id) + command_string
        buf = unpack('8B' + '%sB' % len(command_string), buf)
        checksum = unpack('H', self.__create_checksum(buf))[0]
        reply_id += 1
        if reply_id >= const.USHRT_MAX:
            reply_id -= const.USHRT_MAX

        buf = pack('<4H', command, checksum, session_id, reply_id)
        return buf + command_string

    def __create_checksum(self, p):
        '''
        Calculates the checksum of the packet to be sent to the time clock
        Copied from zkemsdk.c
        '''
        l = len(p)
        checksum = 0
        while l > 1:
            checksum += unpack('H', pack('BB', p[0], p[1]))[0]
            p = p[2:]
            if checksum > const.USHRT_MAX:
                checksum -= const.USHRT_MAX
            l -= 2
        if l:
            checksum = checksum + p[-1]

        while checksum > const.USHRT_MAX:
            checksum -= const.USHRT_MAX

        checksum = ~checksum

        while checksum < 0:
            checksum += const.USHRT_MAX

        return pack('H', checksum)

    def __test_tcp_top(self, packet):
        """ return size!"""
        if len(packet)<=8:
            return 0 # invalid packet
        tcp_header = unpack('<HHI', packet[:8])
        if tcp_header[0] == const.MACHINE_PREPARE_DATA_1 and tcp_header[1] == const.MACHINE_PREPARE_DATA_2:
            return tcp_header[2]
        return 0 #never everis 0!

    def __send_command(self, command, command_string=b'', response_size=8):
        '''
        send command to the terminal
        '''
        buf = self.__create_header(command, command_string, self.__session_id, self.__reply_id)
        try:
            if self.tcp:
                top = self.__create_tcp_top(buf)
                self.__sock.send(top)
                self.__tcp_data_recv = self.__sock.recv(response_size + 8)
                self.__tcp_length = self.__test_tcp_top(self.__tcp_data_recv)
                if self.__tcp_length == 0:
                    raise ZKNetworkError("TCP packet invalid")
                self.__header = unpack('<4H', self.__tcp_data_recv[8:16])
                self.__data_recv = self.__tcp_data_recv[8:] # dirty hack
            else:
                self.__sock.sendto(buf, self.__address)
                self.__data_recv = self.__sock.recv(response_size)
                self.__header = unpack('<4H', self.__data_recv[:8])
        except Exception as e:
            raise ZKNetworkError(str(e))

        self.__response = self.__header[0]
        self.__reply_id = self.__header[3]
        self.__data = self.__data_recv[8:] #could be empty
        if self.__response in [const.CMD_ACK_OK, const.CMD_PREPARE_DATA, const.CMD_DATA]:
            return {
                'status': True,
                'code': self.__response
            }
        return {
            'status': False,
            'code': self.__response
        }

    def __ack_ok(self):
        """ event ack ok """
        buf = self.__create_header(const.CMD_ACK_OK, b'', self.__session_id, const.USHRT_MAX - 1)
        try:
            if self.tcp:
                top = self.__create_tcp_top(buf)
                self.__sock.send(top)
            else:
                self.__sock.sendto(buf, self.__address)
        except Exception as e:
            raise ZKNetworkError(str(e))

    def __get_data_size(self):
        """Checks a returned packet to see if it returned CMD_PREPARE_DATA,
        indicating that data packets are to be sent

        Returns the amount of bytes that are going to be sent"""
        response = self.__response
        if response == const.CMD_PREPARE_DATA:
            size = unpack('I', self.__data[:4])[0]
            return size
        else:
            return 0

    def __reverse_hex(self, hex):
        data = ''
        for i in reversed(xrange(len(hex) / 2)):
            data += hex[i * 2:(i * 2) + 2]
        return data

    def __decode_time(self, t):
        """Decode a timestamp retrieved from the timeclock

        copied from zkemsdk.c - DecodeTime"""
        """
        t = t.encode('hex')
        t = int(self.__reverse_hex(t), 16)
        if self.verbose: print ("decode from  %s "% format(t, '04x'))
        """
        t = unpack("<I", t)[0]
        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(year, month, day, hour, minute, second)

        return d
    def __decode_timehex(self, timehex):
        """timehex string of six bytes"""
        year, month, day, hour, minute, second = unpack("6B", timehex)
        year += 2000
        d = datetime(year, month, day, hour, minute, second)
        return d
    def __encode_time(self, t):
        """Encode a timestamp so that it can be read on the timeclock
        """
        # formula taken from zkemsdk.c - EncodeTime
        # can also be found in the technical manual
        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 connect(self):
        '''
        connect to the device
        '''
        self.end_live_capture = False # jic
        if not self.ommit_ping and not self.helper.test_ping():
            raise ZKNetworkError("can't reach device (ping %s)" % self.__address[0])
        if not self.force_udp and self.helper.test_tcp() == 0: #ok
            self.tcp = True
            self.user_packet_size = 72 # default zk8
        self.__create_socket()# tcp based
        self.__session_id = 0
        self.__reply_id = const.USHRT_MAX - 1
        cmd_response = self.__send_command(const.CMD_CONNECT)
        self.__session_id = self.__header[2]
        if cmd_response.get('code') == const.CMD_ACK_UNAUTH:
            if self.verbose: print ("try auth")
            command_string = make_commkey(self.__password, self.__session_id)
            cmd_response = self.__send_command(const.CMD_AUTH, command_string)
        if cmd_response.get('status'):
            self.is_connect = True
            # set the session id
            return self
        else:
            if cmd_response["code"] == const.CMD_ACK_UNAUTH:
                raise ZKErrorResponse("Unauthenticated")
            if self.verbose: print ("connect err response {} ".format(cmd_response["code"]))
            raise ZKErrorResponse("Invalid response: Can't connect")

    def disconnect(self):
        '''
        diconnect from the connected device
        '''
        self.is_connect = False
        cmd_response = self.__send_command(const.CMD_EXIT)
        if cmd_response.get('status'):
            if self.__sock:
                self.__sock.close() #leave to GC
            return True
        else:
            raise ZKErrorResponse("can't disconnect")

    def disable_device(self):
        '''
        disable (lock) device, ensure no activity when process run
        '''
        cmd_response = self.__send_command(const.CMD_DISABLEDEVICE)
        if cmd_response.get('status'):
            self.is_enabled = False
            return True
        else:
            raise ZKErrorResponse("Can't Disable")

    def enable_device(self):
        '''
        re-enable the connected device
        '''
        cmd_response = self.__send_command(const.CMD_ENABLEDEVICE)
        if cmd_response.get('status'):
            self.is_enabled = True
            return True
        else:
            raise ZKErrorResponse("Can't enable device")

    def get_firmware_version(self):
        '''
        return the firmware version
        '''
        cmd_response = self.__send_command(const.CMD_GET_VERSION,b'', 1024)
        if cmd_response.get('status'):
            firmware_version = self.__data.split(b'\x00')[0]
            return firmware_version.decode()
        else:
            raise ZKErrorResponse("Can't read frimware version")

    def get_serialnumber(self):
        '''
        return the serial number
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'~SerialNumber'
        response_size = 1024
        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            serialnumber = self.__data.split(b'=', 1)[-1].split(b'\x00')[0]
            serialnumber = serialnumber.replace(b'=', b'')
            return serialnumber.decode() # string?
        else:
            raise ZKErrorResponse("Can't read serial number")

    def get_platform(self):
        '''
        return the platform name
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'~Platform'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            platform = self.__data.split(b'=', 1)[-1].split(b'\x00')[0]
            platform = platform.replace(b'=', b'')
            return platform.decode()
        else:
            raise ZKErrorResponse("Can't get platform")

    def get_mac(self):
        '''
        return the mac
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'MAC'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            mac = self.__data.split(b'=', 1)[-1].split(b'\x00')[0]
            return mac.decode()
        else:
            raise ZKErrorResponse("can't get mac")

    def get_device_name(self):
        '''
        return the device name
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'~DeviceName'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            device = self.__data.split(b'=', 1)[-1].split(b'\x00')[0]
            return device.decode()
        else:
            return "" #no name
            #raise ZKErrorResponse("can't read device name")

    def get_face_version(self):
        '''
        return the face version
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'ZKFaceVersion'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            response = self.__data.split(b'=', 1)[-1].split(b'\x00')[0]
            return safe_cast(response, int, 0)  if response else 0
        else:
            return None

    def get_fp_version(self):
        '''
        return the fingerprint version
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'~ZKFPVersion'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            response = self.__data.split(b'=', 1)[-1].split(b'\x00')[0]
            response = response.replace(b'=', b'')
            return safe_cast(response, int, 0) if response else 0
        else:
            return None

    def get_extend_fmt(self):
        '''
        determine extend fmt
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'~ExtendFmt'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            fmt = (self.__data.split(b'=', 1)[-1].split(b'\x00')[0])
            #definitivo? seleccionar firmware aqui?
            return safe_cast(fmt, int, 0) if fmt else 0
        else:
            raise ZKErrorResponse("Can't read extend fmt")

    def get_user_extend_fmt(self):
        '''
        determine user extend fmt
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'~UserExtFmt'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            fmt = (self.__data.split(b'=', 1)[-1].split(b'\x00')[0])
            #definitivo? seleccionar firmware aqui?
            return safe_cast(fmt, int, 0) if fmt else 0
        else:
            return None

    def get_face_fun_on(self):
        '''
        determine extend fmt
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'FaceFunOn'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            response = (self.__data.split(b'=', 1)[-1].split(b'\x00')[0])
            #definitivo? seleccionar firmware aqui?
            return int(response) if response else 0
        else:
            return None

    def get_compat_old_firmware(self):
        '''
        determine old firmware
        '''
        command = const.CMD_OPTIONS_RRQ
        command_string = b'CompatOldFirmware'
        response_size = 1024

        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            response = (self.__data.split(b'=', 1)[-1].split(b'\x00')[0])
            #definitivo? seleccionar firmware aqui?
            return safe_cast(response, int, 0) if response else 0
        else:
            return None

    def get_network_params(self):
        ip = self.__address[0]
        mask = b''
        gate = b''
        cmd_response = self.__send_command(const.CMD_OPTIONS_RRQ, b'IPAddress', 1024)
        if cmd_response.get('status'):
            ip = (self.__data.split(b'=', 1)[-1].split(b'\x00')[0])
        cmd_response = self.__send_command(const.CMD_OPTIONS_RRQ, b'NetMask', 1024)
        if cmd_response.get('status'):
            mask = (self.__data.split(b'=', 1)[-1].split(b'\x00')[0])
        cmd_response = self.__send_command(const.CMD_OPTIONS_RRQ, b'GATEIPAddress', 1024)
        if cmd_response.get('status'):
            gate = (self.__data.split(b'=', 1)[-1].split(b'\x00')[0])
        return {'ip': ip.decode(), 'mask': mask.decode(), 'gateway': gate.decode()}

    def get_pin_width(self):
        '''
        return the serial number
        '''
        command = const.CMD_GET_PINWIDTH
        command_string = b' P'
        response_size = 9
        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            width = self.__data.split(b'\x00')[0]
            return bytearray(width)[0]
        else:
            raise ZKErrorResponse("can0t get pin width")

    def free_data(self):
        """ clear buffer"""
        command = const.CMD_FREE_DATA
        cmd_response = self.__send_command(command)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("can't free data")

    def read_sizes(self):
        """ read sizes """
        command = const.CMD_GET_FREE_SIZES
        response_size = 1024
        cmd_response = self.__send_command(command,b'', response_size)
        if cmd_response.get('status'):
            if self.verbose: print(codecs.encode(self.__data,'hex'))
            size = len(self.__data)
            if len(self.__data) >= 80:
                fields = unpack('20i', self.__data[:80])
                self.users = fields[4]
                self.fingers = fields[6]
                self.records = fields[8]
                self.dummy = fields[10] #???
                self.cards = fields[12]
                self.fingers_cap = fields[14]
                self.users_cap = fields[15]
                self.rec_cap = fields[16]
                self.fingers_av = fields[17]
                self.users_av = fields[18]
                self.rec_av = fields[19]
                self.__data = self.__data[80:]
            if len(self.__data) >= 12: #face info
                fields = unpack('3i', self.__data[:12]) #dirty hack! we need more information
                self.faces = fields[0]
                self.faces_cap = fields[2]
            return True
        else:
            raise ZKErrorResponse("can't read sizes")

    def unlock(self, time=3):
        '''
        :param time: define time in seconds
        :return:
        thanks to https://github.com/SoftwareHouseMerida/pyzk/
        '''
        command = const.CMD_UNLOCK
        command_string = pack("I",int(time)*10)
        cmd_response = self.__send_command(command, command_string)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("Can't open door")

    def __str__(self):
        """ for debug"""
        return "ZK %s://%s:%s users[%i]:%i/%i fingers:%i/%i, records:%i/%i faces:%i/%i" % (
            "tcp" if self.tcp else "udp", self.__address[0], self.__address[1],
            self.user_packet_size, self.users, self.users_cap,
            self.fingers, self.fingers_cap,
            self.records, self.rec_cap,
            self.faces, self.faces_cap
        )

    def restart(self):
        '''
        restart the device
        '''
        command = const.CMD_RESTART
        cmd_response = self.__send_command(command)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("can't restart device")

    def get_time(self):
        """get Device Time"""
        command = const.CMD_GET_TIME
        response_size = 1032
        cmd_response = self.__send_command(command, b'', response_size)
        if cmd_response.get('status'):
            return self.__decode_time(self.__data[:4])
        else:
            raise ZKErrorResponse("can't get time")

    def set_time(self, timestamp):
        """ set Device time (pass datetime object)"""
        command = const.CMD_SET_TIME
        command_string = pack(b'I', self.__encode_time(timestamp))
        cmd_response = self.__send_command(command, command_string)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("can't set time")

    def poweroff(self):
        '''
        shutdown the device
        '''
        command = const.CMD_POWEROFF
        command_string = b''
        response_size = 1032
        cmd_response = self.__send_command(command, command_string, response_size)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("can't poweroff")

    def refresh_data(self):
        '''
        shutdown the device
        '''
        command = const.CMD_REFRESHDATA
        cmd_response = self.__send_command(command)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("can't refresh data")

    def test_voice(self, index=0):
        '''
        play test voice
         0 acceso correcto / acceso correcto
         1 password incorrecto / clave incorrecta
         2 la memoria del terminal está llena / acceso denegado
         3 usuario invalido /codigo no valido
         4 intente de nuevo  por favor / intente de nuevo por favor *
         5 reintroduszca codigo de usuario /reintroduszca codigo
         6 memoria del terminal llena /-
         7 memoria de alm fich llena /-
         8 huella duplicada / huella duplicada
         9 acceso denegado / ya ha sido registrado
         10 *beep* / beep kuko
         11 el sistema vuelve al modo de verificacion / beep siren
         12 por favor coloque su dedo  o acerque tarjeta  /-
         13 acerca su tarjeta de nuevo  /beep bell
         14 excedido tiempo p esta operacion  /-
         15 coloque su dedo de nuevo  /-
         16 coloque su dedo por ultima vez  /-
         17 ATN numero de tarjeta está repetida  /-
         18 proceso de registro correcto *  /-
         19 borrado correcto /-
         20 Numero de usuario / ponga la caja de ojos
         21 ATN se ha llegado al max num usuarios /-
         22 verificacion de usuarios /-
         23 usuario no registrado /-
         24 ATN se ha llegado al num max de registros /-
         25 ATN la puerta no esta cerrada /-
         26 registro de usuarios /-
         27 borrado de usuarios /-
         28 coloque su dedo  /-
         29 registre la tarjeta de administrador /-
         30 0 /-
         31 1 /-
         32 2 /-
         33 3 /-
         34 4 /-
         35 5 /-
         36 6 /-
         37 7 /-
         38 8 /-
         39 9 /-
         40 PFV seleccione numero de usuario /-
         41 registrar /-
         42 operacion correcta /-
         43 PFV acerque su tarjeta /-
         43 la tarjeta ha sido registrada /-
         45 error en operacion /-
         46 PFV acerque tarjeta de administracion, p confirmacion /-
         47 descarga de fichajes /-
         48 descarga de usuarios /-
         49 carga de usuarios /-
         50 actualizan de firmware /-
         51 ejeuctar ficheros de configuracion /-
         52 confirmación de clave de acceso correcta /-
         53 error en operacion de tclado /-
         54 borrar todos los usuarios /-
         55 restaurar terminal con configuracion por defecto /-
         56 introduzca numero de usuario /-
         57 teclado bloqueado /-
         58 error en la gestión de la tarjeta  /-
         59 establezca una clave de acceso /-
         60 pulse el teclado  /-
         61 zona de accceso invalida /-
         62 acceso combinado invĺlido /-
         63 verificación multiusuario /-
         64 modo de verificación inválido /-
         65 - /-

        '''
        command = const.CMD_TESTVOICE
        command_string = pack("I", index)
        cmd_response = self.__send_command(command, command_string)
        if cmd_response.get('status'):
            return True
        else:
            return False #some devices doesn't support sound
            #raise ZKErrorResponse("can't test voice")

    def set_user(self, uid=None, name='', privilege=0, password='', group_id='', user_id='', card=0):
        '''
        create or update user by uid
        '''
        command = const.CMD_USER_WRQ
        if uid is None:
            uid = self.next_uid # keeps uid=0
            if not user_id:
                user_id = self.next_user_id # else...
        if not user_id:
            user_id = str(uid) #ZK6 needs uid2 == uid
        #TODO: check what happens if name is missing...
        if privilege not in [const.USER_DEFAULT, const.USER_ADMIN]:
            privilege = const.USER_DEFAULT
        privilege = int(privilege)
        if self.user_packet_size == 28: #self.firmware == 6:
            if not group_id:
                group_id = 0
            try:
                command_string = pack('HB5s8sIxBHI', uid, privilege, password.encode(self.encoding, errors='ignore'), name.encode(self.encoding, errors='ignore'), card, int(group_id), 0, int(user_id))
            except Exception as e:
                if self.verbose: print("s_h Error pack: %s" % e)
                if self.verbose: print("Error pack: %s" % sys.exc_info()[0])
                raise ZKErrorResponse("Can't pack user")
        else:
            name_pad = name.encode(self.encoding, errors='ignore').ljust(24, b'\x00')[:24]
            card_str = pack('i', int(card))[:4]
            command_string = pack('HB8s24s4sx7sx24s', uid, privilege, password.encode(self.encoding, errors='ignore'), name_pad, card_str, group_id.encode(), user_id.encode())
        response_size = 1024 #TODO check response?
        cmd_response = self.__send_command(command, command_string, response_size)
        if not cmd_response.get('status'):
            raise ZKErrorResponse("Can't set user")
        self.refresh_data()
        if self.next_uid == uid:
            self.next_uid += 1 # better recalculate again
        if self.next_user_id == user_id:
            self.next_user_id = str(self.next_uid)

    def save_user_template(self, user, fingers=[]):
        """ save user and template """
        #TODO: grabado global
        # armar paquete de huellas
        if not isinstance(user, User):
            #try uid
            users = self.get_users()
            tusers = list(filter(lambda x: x.uid==user, users))
            if len(tusers) == 1:
                user = tusers[0]
            else:
                tusers = list(filter(lambda x: x.user_id==str(user), users))
                if len(tusers) == 1:
                    user = tusers[0]
                else:
                    raise ZKErrorResponse("Can't find user")
        if isinstance(fingers, Finger):
            fingers = [fingers]
        fpack = b""
        table = b""
        fnum = 0x10 # possibly flag
        tstart = 0
        for finger in fingers:
            tfp = finger.repack_only()
            table += pack("<bHbI", 2, user.uid, fnum + finger.fid, tstart)
            tstart += len(tfp)
            fpack += tfp
        if self.user_packet_size == 28: #self.firmware == 6:
            upack = user.repack29()
        else: # 72
            upack = user.repack73()
        head = pack("III", len(upack), len(table), len(fpack))
        packet = head + upack + table + fpack
        self._send_with_buffer(packet)
        command = 110 # Unknown
        command_string = pack('<IHH', 12,0,8) # ??? write? WRQ user data?
        cmd_response = self.__send_command(command, command_string)
        if not cmd_response.get('status'):
            raise ZKErrorResponse("Can't save utemp")
        self.refresh_data()

    def _send_with_buffer(self, buffer):
        MAX_CHUNK = 1024
        size = len(buffer)
        #free_Data
        self.free_data()
        # send prepare_data
        command = const.CMD_PREPARE_DATA
        command_string = pack('I', size)
        cmd_response = self.__send_command(command, command_string)
        if not cmd_response.get('status'):
            raise ZKErrorResponse("Can't prepare data")
        remain = size % MAX_CHUNK
        packets = (size - remain) // MAX_CHUNK
        start = 0
        for _wlk in range(packets):
            self.__send_chunk(buffer[start:start+MAX_CHUNK])
            start += MAX_CHUNK
        if remain:
            self.__send_chunk(buffer[start:start+remain])

    def __send_chunk(self, command_string):
        command = const.CMD_DATA
        cmd_response = self.__send_command(command, command_string)
        if cmd_response.get('status'):
            return True #refres_data (1013)?
        else:
            raise ZKErrorResponse("Can't send chunk")

    def delete_user_template(self, uid=0, temp_id=0, user_id=''):
        """
        Delete specific template
        for tcp via user_id:
        """
        if self.tcp and user_id:
            command = 134 # unknown?
            command_string = pack('<24sB', str(user_id), temp_id)
            cmd_response = self.__send_command(command, command_string)
            #        users = list(filter(lambda x: x.uid==uid, users))
            if cmd_response.get('status'):
                return True #refres_data (1013)?
            else:
                return False # probably empty!
        if not uid:
            users = self.get_users()
            users = list(filter(lambda x: x.user_id==str(user_id), users))
            if not users:
                return False
            uid = users[0].uid
        command = const.CMD_DELETE_USERTEMP
        command_string = pack('hb', uid, temp_id)
        cmd_response = self.__send_command(command, command_string)
        #        users = list(filter(lambda x: x.uid==uid, users))
        if cmd_response.get('status'):
            return True #refres_data (1013)?
        else:
            return False # probably empty!

    def delete_user(self, uid=0, user_id=''):
        '''
        delete specific user by uid
        '''
        """if self.tcp: should work but not tested
            if  not user_id:
                #we need user_id (uid2)
                users = self.get_users()
                if len(users) == 1:
                    user_id = users[0].user_id
                else: #double? posibly empty
                    return False #can't enrool
            command = 133 #const.CMD_DELETE_USER_2
            command_string = pack('24s',str(user_id))
        else:"""
        if not uid:
            users = self.get_users()
            users = list(filter(lambda x: x.user_id==str(user_id), users))
            if not users:
                return False
            uid = users[0].uid
        command = const.CMD_DELETE_USER
        command_string = pack('h', uid)
        cmd_response = self.__send_command(command, command_string)
        if not cmd_response.get('status'):
            raise ZKErrorResponse("Can't delete user")
        self.refresh_data()
        if uid == (self.next_uid - 1):
            self.next_uid = uid # quick undo

    def get_user_template(self, uid, temp_id=0, user_id=''):
        """ ZKFinger VX10.0
            for tcp:
            command = const.CMD_USERTEMP_RRQ (doesn't work always)
            command_string = pack('hb', uid, temp_id)
        """
        if not uid:
            users = self.get_users()
            users = list(filter(lambda x: x.user_id==str(user_id), users))
            if not users:
                return False
            uid = users[0].uid
        for _retries in range(3):
            command = 88 # comando secreto!!! GET_USER_TEMPLATE
            command_string = pack('hb', uid, temp_id)
            response_size = 1024 + 8
            cmd_response = self.__send_command(command, command_string, response_size)
            data = self.__recieve_chunk()
            if data is not None:
                resp = data[:-1] # 01, valid byte?
                if resp[-6:] == b'\x00\x00\x00\x00\x00\x00': # padding? bug?
                    resp = resp[:-6]
                return Finger(uid, temp_id, 1, resp)
            if self.verbose: print ("retry get_user_template")
        else:
            if self.verbose: print ("Can't read/find finger")
            return None

    def get_templates(self):
        """ return array of all fingers """
        templates = []
        templatedata, size = self.read_with_buffer(const.CMD_DB_RRQ, const.FCT_FINGERTMP)
        if size < 4:
            if self.verbose: print("WRN: no user data") # debug
            return []
        total_size = unpack('i', templatedata[0:4])[0]
        if self.verbose: print ("get template total size {}, size {} len {}".format(total_size, size, len(templatedata)))
        templatedata = templatedata[4:] #total size not used
        # ZKFinger VX10.0 the only finger firmware tested
        while total_size:
            #print ("total_size {}".format(total_size))
            size, uid, fid, valid = unpack('HHbb',templatedata[:6])
            template = unpack("%is" % (size-6), templatedata[6:size])[0]
            finger = Finger(uid, fid, valid, template)
            if self.verbose: print(finger) # test
            templates.append(finger)
            templatedata = templatedata[size:]
            total_size -= size
        return templates

    def get_users(self): #ALWAYS CALL TO GET correct user_packet_size
        """ return all user """
        self.read_sizes() # last update
        if self.users == 0: #lazy
            self.next_uid = 1
            self.next_user_id='1'
            return []
        users = []
        max_uid = 0
        userdata, size = self.read_with_buffer(const.CMD_USERTEMP_RRQ, const.FCT_USER)
        if self.verbose: print("user size {} (= {})".format(size, len(userdata)))
        if size <= 4:
            print("WRN: missing user data")# debug
            return []
        total_size = unpack("I",userdata[:4])[0]
        self.user_packet_size = total_size / self.users
        if not self.user_packet_size in [28, 72]:
            if self.verbose: print("WRN packet size would be  %i" % self.user_packet_size)
        userdata = userdata[4:]
        if self.user_packet_size == 28:
            while len(userdata) >= 28:
                uid, privilege, password, name, card, group_id, timezone, user_id = unpack('<HB5s8sIxBhI',userdata.ljust(28, b'\x00')[:28])
                if uid > max_uid: max_uid = uid
                password = (password.split(b'\x00')[0]).decode(self.encoding, errors='ignore')
                name = (name.split(b'\x00')[0]).decode(self.encoding, errors='ignore').strip()
                #card = unpack('I', card)[0] #or hex value?
                group_id = str(group_id)
                user_id = str(user_id)
                #TODO: check card value and find in ver8
                if not name:
                    name = "NN-%s" % user_id
                user = User(uid, name, privilege, password, group_id, user_id, card)
                users.append(user)
                if self.verbose: print("[6]user:",uid, privilege, password, name, card, group_id, timezone, user_id)
                userdata = userdata[28:]
        else:
            while len(userdata) >= 72:
                uid, privilege, password, name, card, group_id, user_id = unpack('<HB8s24sIx7sx24s', userdata.ljust(72, b'\x00')[:72])
                #u1 = int(uid[0].encode("hex"), 16)
                #u2 = int(uid[1].encode("hex"), 16)
                #uid = u1 + (u2 * 256)
                #privilege = int(privilege.encode("hex"), 16)
                password = (password.split(b'\x00')[0]).decode(self.encoding, errors='ignore')
                name = (name.split(b'\x00')[0]).decode(self.encoding, errors='ignore').strip()
                group_id = (group_id.split(b'\x00')[0]).decode(self.encoding, errors='ignore').strip()
                user_id = (user_id.split(b'\x00')[0]).decode(self.encoding, errors='ignore')
                if uid > max_uid: max_uid = uid
                #card = int(unpack('I', separator)[0])
                if not name:
                    name = "NN-%s" % user_id
                user = User(uid, name, privilege, password, group_id, user_id, card)
                users.append(user)
                userdata = userdata[72:]
        #get limits!
        max_uid += 1
        self.next_uid = max_uid
        self.next_user_id = str(max_uid)
        #re check
        while True:
            if any(u for u in users if u.user_id == self.next_user_id):
                max_uid += 1
                self.next_user_id = str(max_uid)
            else:
                break
        return users

    def cancel_capture(self):
        '''
        cancel capturing finger
        '''
        command = const.CMD_CANCELCAPTURE
        cmd_response = self.__send_command(command)
        return bool(cmd_response.get('status'))

    def verify_user(self):
        '''
        start verify finger mode (after capture)
        '''
        command = const.CMD_STARTVERIFY
        # uid = chr(uid % 256) + chr(uid >> 8)
        cmd_response = self.__send_command(command)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("Cant Verify")

    def reg_event(self, flags):
        """ reg events, """
        command = const.CMD_REG_EVENT
        command_string = pack ("I", flags)
        cmd_response = self.__send_command(command, command_string)
        if not cmd_response.get('status'):
            raise ZKErrorResponse("cant' reg events %i" % flags)

    def set_sdk_build_1(self):
        """ """
        command = const.CMD_OPTIONS_WRQ
        command_string = b"SDKBuild=1"
        cmd_response = self.__send_command(command, command_string)
        if not cmd_response.get('status'):
            return False #raise ZKErrorResponse("can't set sdk build ")
        return True

    def enroll_user(self, uid=0, temp_id=0, user_id=''):
        '''
        start enroll user
        we need user_id (uid2)
        '''
        command = const.CMD_STARTENROLL
        done = False
        if  not user_id:
            #we need user_id (uid2)
            users = self.get_users()
            users = list(filter(lambda x: x.uid==uid, users))
            if len(users) >= 1:
                user_id = users[0].user_id
            else: #double? posibly empty
                return False #can't enroll
        if self.tcp:
            command_string = pack('<24sbb',str(user_id).encode(), temp_id, 1) # el 1 es misterio
        else:
            command_string = pack('<Ib', int(user_id), temp_id) #
        self.cancel_capture()
        cmd_response = self.__send_command(command, command_string)
        if not cmd_response.get('status'):
            raise ZKErrorResponse("Cant Enroll user #%i [%i]" %(uid, temp_id))
        #retorna rapido toca esperar un reg event
        self.__sock.settimeout(60)# default 1min for finger
        attempts = 3
        while attempts:
            if self.verbose: print("A:%i esperando primer regevent" % attempts)
            data_recv = self.__sock.recv(1032) # timeout? tarda bastante...
            self.__ack_ok()
            if self.verbose: print(codecs.encode(data_recv,'hex'))
            if self.tcp:
                if len(data_recv) > 16: #not empty
                    res = unpack("H", data_recv.ljust(24,b"\x00")[16:18])[0]
                    if self.verbose: print("res %i" % res)
                    if res == 0 or res == 6 or res == 4:
                        # 6 timeout, 4 mismatch error, 0 can't start(why?)
                        if self.verbose: print ("posible timeout  o reg Fallido")
                        break
            else:
                if len(data_recv) > 8: #not empty
                    res = unpack("H", data_recv.ljust(16,b"\x00")[8:10])[0]
                    if self.verbose: print("res %i" % res)
                    if res == 6 or res == 4:
                        if self.verbose: print ("posible timeout  o reg Fallido")
                        break
            if self.verbose: print ("A:%i esperando 2do regevent" % attempts)
            data_recv = self.__sock.recv(1032) # timeout? tarda bastante...
            self.__ack_ok()
            if self.verbose: print (codecs.encode(data_recv, 'hex'))
            if self.tcp:
                if len(data_recv) > 8: #not empty
                    res = unpack("H", data_recv.ljust(24,b"\x00")[16:18])[0]
                    if self.verbose: print("res %i" % res)
                    if res == 6 or res == 4:
                        if self.verbose: print ("posible timeout  o reg Fallido")
                        break
                    elif res == 0x64:
                        if self.verbose: print ("ok, continue?")
                        attempts -= 1
            else:
                if len(data_recv) > 8: #not empty
                    res = unpack("H", data_recv.ljust(16,b"\x00")[8:10])[0]
                    if self.verbose: print("res %i" % res)
                    if res == 6 or res == 4:
                        if self.verbose: print ("posible timeout  o reg Fallido")
                        break
                    elif res == 0x64:
                        if self.verbose: print ("ok, continue?")
                        attempts -= 1
        if attempts == 0:
            if self.verbose: print ("esperando 3er regevent")
            data_recv = self.__sock.recv(1032) # timeout? tarda bastante...
            self.__ack_ok()
            if self.verbose: print (codecs.encode(data_recv, 'hex'))
            if self.tcp:
                res = unpack("H", data_recv.ljust(24,b"\x00")[16:18])[0]
            else:
                res = unpack("H", data_recv.ljust(16,b"\x00")[8:10])[0]
            if self.verbose: print("res %i" % res)
            if res == 5:
                if self.verbose: print ("huella duplicada")
            if res == 6 or res == 4:
                if self.verbose: print ("posible timeout  o reg Fallido")
            if res  == 0:
                size = unpack("H", data_recv.ljust(16,b"\x00")[10:12])[0]
                pos = unpack("H", data_recv.ljust(16,b"\x00")[12:14])[0]
                if self.verbose: print("enroll ok", size, pos)
                done = True
        self.__sock.settimeout(self.__timeout)
        self.reg_event(0) # TODO: test
        self.cancel_capture()
        self.verify_user()
        return done

    def live_capture(self, new_timeout=10):# generator!
        """ try live capture of events"""
        was_enabled = self.is_enabled
        users = self.get_users()
        self.cancel_capture()
        self.verify_user()
        if not self.is_enabled:
            self.enable_device()
        self.reg_event(const.EF_ATTLOG) #0xFFFF
        self.__sock.settimeout(new_timeout) # default 1 minute test?
        self.end_live_capture = False
        while not self.end_live_capture:
            try:
                if self.verbose: print ("esperando event")
                data_recv = self.__sock.recv(1032)
                self.__ack_ok()
                if self.tcp:
                    size = unpack('<HHI', data_recv[:8])[2]
                    header = unpack('HHHH', data_recv[8:16])
                    data = data_recv[16:]
                else:
                    size = len(data_recv)
                    header = unpack('<4H', data_recv[:8])
                    data = data_recv[8:]
                if not header[0] == const.CMD_REG_EVENT:
                    if self.verbose: print("not event!")
                    continue # or raise error?
                if not len(data):
                    if self.verbose: print ("empty")
                    continue
                """if len (data) == 5:

                    continue"""
                if len(data) == 12: #class 1 attendance #TODO: RETEST ZK6
                    user_id, status, punch, timehex = unpack('<IBB6s', data)
                    user_id = str(user_id)
                    timestamp = self.__decode_timehex(timehex)
                    tuser = list(filter(lambda x: x.user_id == user_id, users))
                    if not tuser:
                        uid = int(user_id)
                    else:
                        uid = tuser[0].uid
                    yield Attendance(user_id, timestamp, status, punch, uid)#punch test?
                elif len(data) == 36: #class 2 attendance
                    user_id,  status, punch, timehex, res = unpack('<24sBB6sI', data)
                    user_id = (user_id.split(b'\x00')[0]).decode(errors='ignore')
                    timestamp = self.__decode_timehex(timehex)
                    tuser = list(filter(lambda x: x.user_id == user_id, users))
                    if not tuser:
                        uid = int(user_id)
                    else:
                        uid = tuser[0].uid
                    yield Attendance(user_id, timestamp, status, punch, uid)
                else:
                    if self.verbose: print (codecs.encode(data, 'hex')), len(data)
                    yield codecs.encode(data, 'hex')
            except timeout:
                if self.verbose: print ("time out")
                yield None # return to keep watching
            except (KeyboardInterrupt, SystemExit):
                if self.verbose: print ("break")
                break
        if self.verbose: print ("exit gracefully")
        self.__sock.settimeout(self.__timeout)
        self.reg_event(0) # TODO: test
        if not was_enabled:
            self.disable_device()

    def clear_data(self, clear_type=5): # FCT_USER
        '''
        clear all data (include: user, attendance report, finger database )
        2 = FCT_FINGERTMP
        '''
        command = const.CMD_CLEAR_DATA
        command_string = pack("B", clear_type)
        cmd_response = self.__send_command(command, command_string)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("can't clear data")

    def __recieve_tcp_data(self, data_recv, size):
        """ data_recv, raw tcp packet
         must analyze tcp_length

         must return data, broken
         """
        data = []
        tcp_length = self.__test_tcp_top(data_recv) # tcp header
        if self.verbose: print ("tcp_length {}, size {}".format(tcp_length, size))
        if tcp_length <= 0:
            if self.verbose: print ("Incorrect tcp packet")
            return None, b""
        if (tcp_length - 8) < size: #broken on smaller DATAs
            if self.verbose: print ("tcp length too small... retrying")
            resp, bh = self.__recieve_tcp_data(data_recv, tcp_length - 8)
            data.append(resp)
            size -= len(resp)
            if self.verbose: print ("new tcp DATA packet to fill misssing {}".format(size))
            data_recv = bh + self.__sock.recv(size) #ideal limit?
            resp, bh = self.__recieve_tcp_data(data_recv, size)
            data.append(resp)
            if self.verbose: print ("for misssing {} recieved {} with extra {}".format(size, len(resp), len(bh)))
            return b''.join(data), bh
        recieved = len(data_recv)
        if self.verbose: print ("recieved {}, size {}".format(recieved, size))
        #if (tcp_length - 16) > (recieved - 16): #broken first DATA
        #    #reparse as more data packets?
        #    if self.verbose: print ("trying".format(recieved, size))
        #    _data, bh = self.__recieve_tcp_data(data_recv, tcp_length-16)
        #analize first response
        response = unpack('HHHH', data_recv[8:16])[0]
        if recieved >= (size + 32): #complete with ACK_OK included
            if response == const.CMD_DATA:
                resp = data_recv[16 : size + 16] # no ack?
                if self.verbose: print ("resp complete len {}".format(len(resp)))
                return resp, data_recv[size + 16:]
            else:
                if self.verbose: print("incorrect response!!! {}".format(response))
                return None, b"" #broken
        else: # response DATA incomplete (or missing ACK_OK)
            if self.verbose: print ("try DATA incomplete (actual valid {})".format(recieved-16))
            data.append(data_recv[16 : size + 16 ]) # w/o DATA tcp and header
            size -= recieved - 16 # w/o DATA tcp and header
            broken_header = b""
            if size < 0: #broken ack header?
                broken_header = data_recv[size:]
                if self.verbose: print ("broken", (broken_header).encode('hex')) #TODO python3
            if size > 0: #need raw data to complete
                data_recv = self.__recieve_raw_data(size)
                data.append(data_recv) # w/o tcp and header
            return b''.join(data), broken_header
            #get cmd_ack_ok on __rchunk


    def __recieve_raw_data(self, size):
        """ partial data ? """
        data = []
        if self.verbose: print ("expecting {} bytes raw data".format(size))
        while size > 0:
            data_recv = self.__sock.recv(size) #ideal limit?
            recieved = len(data_recv)
            if self.verbose: print ("partial recv {}".format(recieved))
            data.append(data_recv) # w/o tcp and header
            size -= recieved
            if self.verbose: print ("still need {}".format(size))
        return b''.join(data)

    def __recieve_chunk(self):
        """ recieve a chunk """
        if self.__response == const.CMD_DATA: # less than 1024!!!
            if self.tcp: #MUST CHECK TCP SIZE
                if self.verbose: print ("_rc_DATA! is {} bytes, tcp length is {}".format(len(self.__data), self.__tcp_length))
                if len(self.__data) < (self.__tcp_length - 8):
                    need = (self.__tcp_length - 8) - len(self.__data)
                    if self.verbose: print ("need more data: {}".format(need))
                    more_data = self.__recieve_raw_data(need)
                    return b''.join([self.__data, more_data])
                else: #enough data
                    if self.verbose: print ("Enough data")
                    return self.__data
            else: #UDP
                if self.verbose: print ("_rc len is {}".format(len(self.__data)))
                return self.__data #without headers
        elif self.__response == const.CMD_PREPARE_DATA:
            data = []
            size = self.__get_data_size()
            if self.verbose: print ("recieve chunk: prepare data size is {}".format(size))
            if self.tcp:
                if len(self.__data) >= (8 + size): #prepare data with actual data! should be 8+size+32
                    data_recv = self.__data[8:] # test, maybe -32
                else:
                    data_recv = self.__sock.recv(size + 32) #could have two commands
                resp, broken_header = self.__recieve_tcp_data(data_recv, size)
                data.append(resp)
                # get CMD_ACK_OK
                if len(broken_header) < 16:
                    data_recv = broken_header + self.__sock.recv(16)
                else:
                    data_recv = broken_header
                #could be broken
                if len(data_recv) < 16:
                    print ("trying to complete broken ACK %s /16" % len(data_recv))
                    if self.verbose: print (data_recv.encode('hex')) #todo python3
                    data_recv += self.__sock.recv(16 - len(data_recv)) #TODO: CHECK HERE_!
                if not self.__test_tcp_top(data_recv):
                    if self.verbose: print ("invalid chunk tcp ACK OK")
                    return None #b''.join(data) # incomplete?
                response = unpack('HHHH', data_recv[8:16])[0]
                if response == const.CMD_ACK_OK:
                    if self.verbose: print ("chunk tcp ACK OK!")
                    return b''.join(data)
                if self.verbose: print("bad response %s" % data_recv)
                if self.verbose: print (codecs.encode(data,'hex'))
                return None

                return resp
            #else udp
            while True: #limitado por respuesta no por tamaño
                data_recv = self.__sock.recv(1024+8)
                response = unpack('<4H', data_recv[:8])[0]
                if self.verbose: print ("# packet response is: {}".format(response))
                if response == const.CMD_DATA:
                    data.append(data_recv[8:]) #header turncated
                    size -= 1024 #UDP
                elif response == const.CMD_ACK_OK:
                    break #without problem.
                else:
                    #truncado! continuar?
                    if self.verbose: print ("broken!")
                    break
                if self.verbose: print ("still needs %s" % size)
            return b''.join(data)
        else:
            if self.verbose: print ("invalid response %s" % self.__response)
            return None #("can't get user template")

    def __read_chunk(self, start, size):
        """ read a chunk from buffer """
        for _retries in range(3):
            command = 1504 #CMD_READ_BUFFER
            command_string = pack('<ii', start, size)
            if self.tcp:
                response_size = size + 32
            else:
                response_size = 1024 + 8
            cmd_response = self.__send_command(command, command_string, response_size)
            data = self.__recieve_chunk()
            if data is not None:
                return data
        else:
            raise ZKErrorResponse("can't read chunk %i:[%i]" % (start, size))

    def read_with_buffer(self, command, fct=0 ,ext=0):
        """ Test read info with buffered command (ZK6: 1503) """
        if self.tcp:
            MAX_CHUNK = 0xFFc0 #arbitrary, below 0x10008
        else:
            MAX_CHUNK = 16 * 1024
        command_string = pack('<bhii', 1, command, fct, ext)
        if self.verbose: print ("rwb cs", command_string)
        response_size = 1024
        data = []
        start = 0
        cmd_response = self.__send_command(1503, command_string, response_size)
        if not cmd_response.get('status'):
            raise ZKErrorResponse("RWB Not supported")
        if cmd_response['code'] == const.CMD_DATA:
            #direct!!! small!!!
            if self.tcp: #MUST CHECK TCP SIZE
                if self.verbose: print ("DATA! is {} bytes, tcp length is {}".format(len(self.__data), self.__tcp_length))
                if len(self.__data) < (self.__tcp_length - 8):
                    need = (self.__tcp_length - 8) - len(self.__data)
                    if self.verbose: print ("need more data: {}".format(need))
                    more_data = self.__recieve_raw_data(need)
                    return b''.join([self.__data, more_data]), len(self.__data) + len(more_data)
                else: #enough data
                    if self.verbose: print ("Enough data")
                    size = len(self.__data)
                    return self.__data, size
            else: #udp is direct
                size = len(self.__data)
                return self.__data, size
        #else ACK_OK with size
        size = unpack('I', self.__data[1:5])[0]  # extra info???
        if self.verbose: print ("size fill be %i" % size)
        remain = size % MAX_CHUNK
        packets = (size-remain) // MAX_CHUNK # should be size /16k
        if self.verbose: print ("rwb: #{} packets of max {} bytes, and extra {} bytes remain".format(packets, MAX_CHUNK, remain))
        for _wlk in range(packets):
            data.append(self.__read_chunk(start,MAX_CHUNK))
            start += MAX_CHUNK
        if remain:
            data.append(self.__read_chunk(start, remain))
            start += remain # Debug
        self.free_data()
        if self.verbose: print ("_read w/chunk %i bytes" % start)
        return b''.join(data), start

    def get_attendance(self):
        """ return attendance record """
        self.read_sizes()
        if self.records == 0: #lazy
            return []
        users = self.get_users()
        if self.verbose: print (users)
        attendances = []
        attendance_data, size = self.read_with_buffer(const.CMD_ATTLOG_RRQ)
        if size < 4:
            if self.verbose: print ("WRN: no attendance data") # debug
            return []
        total_size = unpack("I", attendance_data[:4])[0]
        record_size = total_size/self.records
        if self.verbose: print ("record_size is ", record_size)
        attendance_data = attendance_data[4:] #total size not used
        if record_size == 8 : #ultra old format
            while len(attendance_data) >= 8:#TODO RETEST ZK6!!!
                uid, status, timestamp, punch = unpack('HB4sB', attendance_data.ljust(8, b'\x00')[:8])
                if self.verbose: print (codecs.encode(attendance_data[:8], 'hex'))
                attendance_data = attendance_data[8:]
                tuser = list(filter(lambda x: x.uid == uid, users))
                if not tuser:
                    user_id = str(uid) #TODO revisar pq
                else:
                    user_id = tuser[0].user_id
                timestamp = self.__decode_time(timestamp)
                attendance = Attendance(user_id, timestamp, status, punch, uid) # punch?
                attendances.append(attendance)
        elif record_size == 16: # extended
            while len(attendance_data) >= 16: #TODO RETEST ZK6
                user_id, timestamp, status, punch, reserved, workcode = unpack('<I4sBB2sI', attendance_data.ljust(16, b'\x00')[:16])
                user_id = str(user_id)
                if self.verbose: print(codecs.encode(attendance_data[:16], 'hex'))
                attendance_data = attendance_data[16:]
                tuser = list(filter(lambda x: x.user_id == user_id, users))
                if not tuser:
                    if self.verbose: print("no uid {}", user_id)
                    uid = str(user_id)
                    tuser = list(filter(lambda x: x.uid == user_id, users)) # refix
                    if not tuser:
                        uid = str(user_id) #TODO revisar pq
                    else:
                        uid = tuser[0].uid
                        user_id = tuser[0].user_id
                else:
                    uid = tuser[0].uid
                timestamp = self.__decode_time(timestamp)
                attendance = Attendance(user_id, timestamp, status, punch, uid)
                attendances.append(attendance)
        else:
            while len(attendance_data) >= 40:
                uid, user_id, status, timestamp, punch, space = unpack('<H24sB4sB8s', attendance_data.ljust(40, b'\x00')[:40])
                if self.verbose: print (codecs.encode(attendance_data[:40], 'hex'))
                user_id = (user_id.split(b'\x00')[0]).decode(errors='ignore')
                timestamp = self.__decode_time(timestamp)
                #status = int(status.encode("hex"), 16)

                attendance = Attendance(user_id, timestamp, status, punch, uid)
                attendances.append(attendance)
                attendance_data = attendance_data[40:]
        return attendances


    def clear_attendance(self):
        '''
        clear all attendance record
        '''
        command = const.CMD_CLEAR_ATTLOG
        cmd_response = self.__send_command(command)
        if cmd_response.get('status'):
            return True
        else:
            raise ZKErrorResponse("can't clear response")