# coding: utf-8

"""
Ctypes wrapper module for BUSMUST CAN Interface on win32/win64 systems.

Authors: busmust <busmust@126.com>, BUSMUST Co.,Ltd.
"""

# Import Standard Python Modules
# ==============================
import ctypes
import logging
import sys
import time
import threading
import os


def set_highest_thread_priority():
    if sys.platform != 'win32':
        return False
    
    import ctypes
    from ctypes import wintypes
    kernel32 = ctypes.windll.kernel32

    GetCurrentThread = kernel32.GetCurrentThread
    GetCurrentThread.argtypes = []
    GetCurrentThread.restype = wintypes.HANDLE

    SetThreadPriority = kernel32.SetThreadPriority
    SetThreadPriority.argtypes = [wintypes.HANDLE, ctypes.c_int]
    SetThreadPriority.restype = wintypes.BOOL

    THREAD_PRIORITY_TIME_CRITICAL = 15

    thread_handle = GetCurrentThread()
    return SetThreadPriority(thread_handle, THREAD_PRIORITY_TIME_CRITICAL)


try:
    # Try builtin Python 3 Windows API
    from _winapi import WaitForSingleObject, INFINITE
    HAS_EVENTS = True
except ImportError:
    try:
        # Try pywin32 package
        from win32event import WaitForSingleObject, INFINITE
        HAS_EVENTS = True
    except ImportError:
        # Use polling instead
        HAS_EVENTS = False

# Import Modules
# ==============
from can import BusABC, Message, CanError
from can.bus import BusState
from can.util import len2dlc, dlc2len
from .exceptions import BmError

# Define Module Logger
# ====================
LOG = logging.getLogger(__name__)

# Import safely Vector API module for Travis tests
bmapi = None
try:
    from . import bmapi
except Exception as exc:
    LOG.error('Could not import bmapi, please check your BMAPI path: %s', exc)
    raise exc

class BmCanTaskWrapper:
    def __init__(self, bus):
        self._bus = bus
        self._txtask_index = -1
        self._bmtxtask = None

    def start(self):
        assert self._txtask_index == -1, "Task is already started"
        index = self.get_first_free_txtask_index()
        if index == -1:
            print("The upper limit of hardware sending tasks is now using software to send tasks")
            return False
        self._bmtxtask.type = bmapi.BM_TXTASK_FIXED
        self._txtask_index = index
        self._bus.add_periodic_txtask(self)
        command = bmapi.BM_CAN_TXTASK_TABLE | bmapi.BM_CAN_CTRL_WR
        bmapi.BM_Control(self._bus._handle, command, index, self._bus._channelinfo.port, ctypes.byref(self._bmtxtask), ctypes.sizeof(self._bmtxtask))
        return True

    def stop(self, remove_tasks=True):
        exist = False
        for task in self._bus._periodic_tasks:
            if isinstance(task, BmCanTaskWrapper):
                if self._txtask_index == task._txtask_index:
                    exist = True
                    break
        if exist:
            self._bmtxtask.type = bmapi.BM_TXTASK_INVALID
            command = bmapi.BM_CAN_TXTASK_TABLE | bmapi.BM_CAN_CTRL_WR
            bmapi.BM_Control(self._bus._handle, command, self._txtask_index, self._bus._channelinfo.port, ctypes.byref(self._bmtxtask), ctypes.sizeof(self._bmtxtask))
            self._txtask_index = -1

    def get_first_free_txtask_index(self):
        for i in range(self._bus._ntxtask):
            exist = False
            for task in self._bus._periodic_tasks:
                if isinstance(task, BmCanTaskWrapper):
                    if i == task._txtask_index:
                        exist = True
                        break
            if not exist:
                return i
        return -1


class BmCanBus(BusABC):
    """The CAN Bus implemented for the BUSMUST USB-CAN interface."""

    __initialized = False
    bus_list = []

    @classmethod
    def __init_class__(cls):
        if bmapi is None:
            raise ImportError("The BMAPI has not been loaded")
        if not BmCanBus.__initialized:
            bmapi.BM_Init()
            bmapi.BM_SetLogLevel(bmapi.BM_LOG_ERR)
            BmCanBus.__initialized = True

    def __init__(self, channel, 
                 fd=True, receive_own_messages=False, listen_only=False,
                 bitrate=500000, data_bitrate=500000, 
                 samplepos=75, data_samplepos = 75,
                 tres=False,
                 can_filters=None,
                 remote_ip=None,
                 remote_enumeration_timeout=100,
				 debug=False,
                 **kwargs):
        """
        :param int channel:
            The channel index to create this bus with, which is the index to all available ports when enumerating Busmust devices.
            Can also be a string of the channel's full name. i.e. "BM-CANFD-X1-PRO(1234) CH1"
        :param bool fd:
            If CAN-FD frames should be supported.
        :param bool receive_own_messages:
            If Loopback mode should be supported.
        :param bool listen_only:
            If Listen only mode should be supported, this is the same as setting 'state' property to INACTIVE.
        :param int bitrate:
            Bitrate in bits/s.
        :param int data_bitrate:
            Which bitrate to use for data phase in CAN FD.
            Defaults to arbitration bitrate.
        :param int samplepos:
            Sample position (%).
        :param int data_samplepos:
            Data phase sample pos (%) in CAN FD.
        :param bool tres:
            If 120Ohm CAN terminal register should be enabled.
        """
        if debug:
            LOG = logging.getLogger(__name__)
            LOG.propagate = False
            LOG_DIR = os.path.dirname('bmcan_bus.log')
            if LOG_DIR and not os.path.exists(LOG_DIR): 
                os.makedirs(LOG_DIR, exist_ok=True)
            if LOG.handlers:
                for handler in LOG.handlers:
                    LOG.removeHandler(handler)
            file_handler = logging.FileHandler(filename='bmcan_bus.log',
                                                mode='a',
                                                encoding='utf-8')
            log_format = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
            file_handler.setFormatter(log_format)
            file_handler.setLevel(logging.INFO)
            LOG.addHandler(file_handler)
            LOG.setLevel(logging.INFO)
            self._log = LOG
        self._debug = debug 
        BmCanBus.__init_class__()
        set_highest_thread_priority()
        self._bmapi = bmapi # Enable external access

        infolist = bmapi.BM_ChannelInfoListTypeDef()
        numOfInfo = ctypes.c_int(len(infolist.entries))
        if remote_ip is None:
            bmapi.BM_EnumerateByCap(ctypes.byref(infolist), ctypes.byref(numOfInfo), bmapi.BM_CAN_CAP)
        else:
            remote_ip_obj = (ctypes.c_uint8 * 4)()
            if type(remote_ip) is bytes:
                for i in range(4):
                    remote_ip_obj[i] = remote_ip[i]
            elif type(remote_ip) is str:
                parts = remote_ip.split('.')
                for i in range(4):
                    remote_ip_obj[i] = int(parts[i])
            else:
                raise BmError(bmapi.BM_ERROR_NODRIVER, "Channel remote address format error:" + str(remote_ip), "BmCanBus.__init__")
            bmapi.BM_EnumerateRemote(ctypes.byref(infolist), ctypes.byref(numOfInfo), remote_ip_obj, remote_enumeration_timeout)
        if isinstance(channel, int):
            if channel < numOfInfo.value:
                self._channelinfo = infolist.entries[channel]
            else:
                raise BmError(bmapi.BM_ERROR_NODRIVER, "Channel %d is not connected or is in use by another app." % channel, "BmCanBus.__init__")
        elif isinstance(channel, str):
            for info in infolist.entries:
                if info.name.decode() == channel:
                    self._channelinfo = info
                    break
            else:
                raise BmError(bmapi.BM_ERROR_NODRIVER, "Channel %s is not connected or is in use by another app." % channel, "BmCanBus.__init__")

        self._mode = bmapi.BM_CAN_NORMAL_MODE
        if not fd:
            self._mode = bmapi.BM_CAN_CLASSIC_MODE
        elif receive_own_messages:
            self._mode = bmapi.BM_CAN_EXTERNAL_LOOPBACK_MODE
        elif listen_only:
            self._mode = bmapi.BM_CAN_LISTEN_ONLY_MODE

        self._tres = bmapi.BM_TRESISTOR_DISABLED
        if tres:
            self._tres = bmapi.BM_TRESISTOR_120

        self._bitrate = bmapi.BM_BitrateTypeDef()
        self._bitrate.nbitrate = int(bitrate / 1000)
        self._bitrate.dbitrate = int(data_bitrate / 1000)
        self._bitrate.nsamplepos = samplepos
        self._bitrate.dsamplepos = data_samplepos

        self._handle = bmapi.BM_ChannelHandle()
        bmapi.BM_OpenEx(
            ctypes.byref(self._handle), 
            ctypes.byref(self._channelinfo), 
            self._mode, 
            self._tres, 
            ctypes.byref(self._bitrate), 
            ctypes.cast(ctypes.c_void_p(), ctypes.POINTER(bmapi.BM_RxFilterListTypeDef)), 0
        )
        super(BmCanBus, self).__init__(channel=channel, can_filters=can_filters, **kwargs)
        timestamp_ns = int(time.time() * 1000000000)
        try:
            bmapi.BM_SetPtpTime(self._handle, ctypes.c_uint64(timestamp_ns))
        except BmError as e:
            print("%s does not support PTP\n" % self._channelinfo.name.decode())
        self.bus_list.append(self)
        self.channel_info = self._channelinfo.name.decode()

        startTimestamp = ctypes.c_uint32()
        bmapi.BM_GetTimestamp(self._handle, ctypes.byref(startTimestamp))
        _time = time.time()
        self._start_time_offset = _time - startTimestamp.value * 1e-6
        self._start_time = _time
        self._old_time = _time
        self._last_hw_timestamp = startTimestamp.value
        self._wraparound_count = 0
        self._time_offset = self._start_time_offset

        self._previous_recovery_ts = _time

        self._notification = bmapi.BM_NotificationHandle()
        bmapi.BM_GetNotification(self._handle, ctypes.byref(self._notification))

        time.sleep(0.05)

        self._state = BusState.ACTIVE
        ntxtask = ctypes.c_int(0) 
        self._isotp_config = bmapi.BM_IsotpConfigTypeDef()
        try:
            result = bmapi.BM_Control(self._handle, bmapi.BM_GET_STAT, bmapi.BM_STAT_MAX_TXTASK, self._channelinfo.port, ctypes.byref(ntxtask), 4)
            if result > 0:
                buf = ctypes.create_string_buffer(256)
                bmapi.BM_GetErrorText(result, buf, len(buf), 0)
                raise BmError(result, buf.value.decode(), "BmCanBus.__init__")
        except BmError as e:
            ntxtask.value = 0
        self._ntxtask = ntxtask.value

        bmtxtask = bmapi.BM_TxTaskTypeDef()
        for index in range(self._ntxtask):
            bmtxtask.type = bmapi.BM_TXTASK_INVALID
            command = bmapi.BM_CAN_TXTASK_TABLE | bmapi.BM_CAN_CTRL_WR
            bmapi.BM_Control(self._handle, command, index, self._channelinfo.port, ctypes.byref(bmtxtask), ctypes.sizeof(bmtxtask))
        self._lock = threading.Lock()
			
    def get_open_time(self):
        return self._start_time
    
    def sync_timestamp(self):
        startTimestamp = ctypes.c_uint32()
        bmapi.BM_GetTimestamp(self._handle, ctypes.byref(startTimestamp))
        self._time_offset = time.time() - startTimestamp.value * 1e-6

    def send_periodic(self, msg, period, duration=None, store_task=True):
        bmtxtask = bmapi.BM_TxTaskTypeDef()
        txtask = BmCanTaskWrapper(self)
        bmtxtask.type = bmapi.BM_TXTASK_FIXED
        bmtxtask.unused = 0
        bmtxtask.flags |= bmapi.BM_MESSAGE_FLAGS_IDE if msg.is_extended_id else 0
        bmtxtask.flags |= bmapi.BM_MESSAGE_FLAGS_RTR if msg.is_remote_frame else 0
        bmtxtask.flags |= bmapi.BM_MESSAGE_FLAGS_FDF if msg.is_fd else 0
        bmtxtask.flags |= bmapi.BM_MESSAGE_FLAGS_BRS if msg.bitrate_switch else 0
        bmtxtask.flags |= bmapi.BM_MESSAGE_FLAGS_ESI if msg.error_state_indicator else 0
        bmtxtask.length = msg.dlc
        bmtxtask.e2e = 0
        bmtxtask.reserved = 0
        cycle = round(period * 1000)
        if duration is not None:
            nrounds = round(duration / period)
            bmtxtask.nrounds = nrounds if nrounds < 0xFFFF else 0xFFFF - 1
        else:
            bmtxtask.nrounds = 0xFFFF
        bmtxtask.cycle = cycle
        bmtxtask.nmessages = 1
        bmtxtask.id = ((msg.arbitration_id << 18) & 0x7FF) | ((msg.arbitration_id) & 0x3FFFF) << 11 if msg.is_extended_id else msg.arbitration_id   
        for i in range(bmtxtask.length):
            bmtxtask.payload[i] = msg.data[i]
        txtask._bus = self
        txtask._bmtxtask = bmtxtask
        succeed = txtask.start()
        if self._ntxtask <= 0 or succeed == False:
            return super().send_periodic(msg, period)
        return txtask

    def stop_all_periodic_tasks(self, remove_tasks=True):
        """Stop sending any messages that were started using **bus.send_periodic**.

        .. note::
            The result is undefined if a single task throws an exception while being stopped.

        :param bool remove_tasks:
            Stop tracking the stopped tasks.
        """
        if self._ntxtask <= 0:
            super().stop_all_periodic_tasks()
        else:
            for txtask in self._periodic_tasks:
                txtask.stop(remove_tasks)
            self._periodic_tasks.clear()
            with self._lock:
                bmapi.BM_ClearBuffer(self._handle)

    def add_periodic_txtask(self, txtask):
        self._periodic_tasks.append(txtask)

    def del_periodic_txtask(self, txtask):
        self._periodic_tasks.remove(txtask)

    def _apply_filters(self, filters):
        if filters:
            # Only up to one filter per ID type allowed
            if len(filters) == 1 or (len(filters) == 2 and filters[0].get("extended") != filters[1].get("extended")):
                bmfilters = bmapi.BM_RxFilterListTypeDef()
                try:
                    for i in range(len(filters)):
                        can_filter = filters[i]
                        bmfilters.entries[i].type = bmapi.BM_RXFILTER_BASIC
                        bmfilters.entries[i].flags_mask = bmapi.BM_MESSAGE_FLAGS_IDE
                        if can_filter.get("extended"):
                            bmfilters.entries[i].flags_value = bmapi.BM_MESSAGE_FLAGS_IDE
                            bmfilters.entries[i].id_mask = (can_filter["can_mask"] >> 18) | ((can_filter["can_mask"] & 0x3FFFF) << 11)
                            bmfilters.entries[i].id_value = (can_filter["can_id"] >> 18) | ((can_filter["can_id"] & 0x3FFFF) << 11)
                        else:
                            bmfilters.entries[i].flags_value = 0
                            bmfilters.entries[i].id_mask = can_filter["can_mask"]
                            bmfilters.entries[i].id_value = can_filter["can_id"]
                    bmapi.BM_SetRxFilters(self._handle, ctypes.byref(bmfilters), len(bmfilters.entries))
                    time.sleep(0.05)
                except BmError as exc:
                    LOG.warning("Could not set filters: %s", exc)
                    # go to fallback
                else:
                    self._is_filtered = True
                    return
            else:
                LOG.warning("Only up to one filter per extended or standard ID allowed")
                # go to fallback

        # fallback: reset filters
        self._is_filtered = False
        try:
            bmfilters = bmapi.BM_RxFilterListTypeDef() # Default as invalid
            # Filter 0: allow all messages to pass
            bmfilters.entries[0].type = bmapi.BM_RXFILTER_BASIC
            bmfilters.entries[0].flags_mask = 0
            bmfilters.entries[0].flags_value = 0
            bmfilters.entries[0].id_mask = 0
            bmfilters.entries[0].id_value = 0
            bmapi.BM_SetRxFilters(self._handle, ctypes.byref(bmfilters), 2)
            time.sleep(0.05)
        except BmError as exc:
            LOG.warning("Could not reset filters: %s", exc)

    def _recv_internal(self, timeout):
        current_time = time.time()
        if (current_time - self._old_time) > 60:
            hw_timestamp = ctypes.c_uint32()
            with self._lock:
                bmapi.BM_GetTimestamp(self._handle, ctypes.byref(hw_timestamp))
            hw_timestamp = hw_timestamp.value
            if hw_timestamp < self._last_hw_timestamp:
                offset = current_time - self._start_time
                self._wraparound_count =  1 + int((offset * 1e6) / 0x100000000)
                self._time_offset = self._start_time_offset + self._wraparound_count * 0x100000000
            self._last_hw_timestamp = hw_timestamp
            self._old_time = current_time
        end_time = time.time() + timeout if timeout is not None else None

        bmmsg = bmapi.BM_DataTypeDef()
        channel = ctypes.c_uint32()
        timestamp = ctypes.c_uint32()
        while True:
            try:
                if self._handle != None:
                    bmapi.BM_Read(self._handle, ctypes.byref(bmmsg))
                    # bmapi.BM_ReadCanMessage(self._handle, ctypes.byref(bmmsg), ctypes.byref(channel), ctypes.byref(timestamp))
                else:
                    self.recover_from_error()
            except BmError as exc:
                if exc.bm_error_code != bmapi.BM_ERROR_QRCVEMPTY:
                    raise
            else:
                istx = bmmsg.header.isackdata()
                canmsg = bmmsg.getCanMessage()
                timestamp = bmmsg.timestamp
                msg_id = canmsg.mid.getExtendedId() if canmsg.ctrl.rx.IDE else canmsg.mid.getStandardId()
                dlc = dlc2len(canmsg.ctrl.rx.DLC)
                tail = bmmsg.getDataTail()
                if tail is not None:
                    #If the message has a tail (available since 3rd generation of Busmust device), take UTC timestamp from the tail object.
                    utcTimestamp = (tail.utctsh << 32) | tail.utctsl
                else:
                    #Keep compatible with legacy hardware which does not support PTP timestamp
                    utcTimestamp = 0
                timestamp = utcTimestamp * 1e-6 if utcTimestamp != 0 else (timestamp * 1e-6 + self._time_offset)
                msg = Message(
                    timestamp=timestamp,
                    arbitration_id=msg_id & 0x1FFFFFFF,
                    is_extended_id=bool(canmsg.ctrl.rx.IDE),
                    is_remote_frame=bool(canmsg.ctrl.rx.RTR),
                    is_error_frame=bool(False),
                    is_fd=bool(canmsg.ctrl.rx.FDF),
                    error_state_indicator=bool(canmsg.ctrl.rx.ESI),
                    bitrate_switch=bool(canmsg.ctrl.rx.BRS),
                    dlc=dlc,
                    data=canmsg.payload[:dlc],
                    channel=None if istx > 0 else channel.value)
                return msg, self._is_filtered


            if end_time is not None and time.time() > end_time:
                return None, self._is_filtered 

            # Wait for receive event to occur
            if timeout is None:
                time_left_ms = INFINITE
            else:
                time_left = end_time - time.time()
                time_left_ms = max(0, int(time_left * 1000))
            bmapi.BM_WaitForNotifications(ctypes.byref(self._notification), 1, time_left_ms)

    def send(self, msg, timeout=None):
        timeoutms = int(timeout*1000) if timeout is not None else -1
        timestamp = ctypes.c_uint32()
        if type(msg) is bmapi.BM_CanMessageTypeDef:
            bmmsg = msg
        else:
            bmmsg = bmapi.BM_CanMessageTypeDef()
            if msg.is_extended_id:
                bmmsg.mid.SID = msg.arbitration_id >> 18
                bmmsg.mid.EID = (msg.arbitration_id & 0x3FFFF)
            else:
                bmmsg.mid.SID = msg.arbitration_id
                bmmsg.mid.EID = 0
            bmmsg.ctrl.tx.IDE = 1 if msg.is_extended_id else 0
            bmmsg.ctrl.tx.FDF = 1 if msg.is_fd else 0
            bmmsg.ctrl.tx.BRS = 1 if msg.bitrate_switch else 0
            bmmsg.ctrl.tx.RTR = 1 if msg.is_remote_frame else 0
            bmmsg.ctrl.tx.ESI = 1 if msg.error_state_indicator else 0
            bmmsg.ctrl.tx.DLC = len2dlc(msg.dlc)
            bmmsg.payload[:len(msg.data)] = msg.data
            try:
                if self._handle != None:
                    bmapi.BM_WriteCanMessage(self._handle, ctypes.byref(bmmsg), 0, timeoutms, ctypes.byref(timestamp))
                else:
                    self.recover_from_error()
            except BmError as e:
                    self.recover_from_error()


    def send_multiple(self, msgs, timeout=None):
        assert(len(msgs) >= 0)
        ntotalmsgs = len(msgs)
        nsentmsgs = 0
        nchunkmsgs = 10000
        bmmsgs = (bmapi.BM_CanMessageTypeDef * nchunkmsgs)()
        nullptr = ctypes.cast(0, ctypes.POINTER(ctypes.c_uint32))
        dataptr = ctypes.cast(bmmsgs, ctypes.POINTER(bmapi.BM_CanMessageTypeDef))
        timeoutms = int(timeout*1000) if timeout is not None else -1
        while nsentmsgs < ntotalmsgs:
            nmsgs = min(nchunkmsgs, ntotalmsgs - nsentmsgs)
            if type(msgs[0]) is bmapi.BM_CanMessageTypeDef:
                bmmsgs[0:nmsgs] = msgs[nsentmsgs:nsentmsgs+nmsgs]
            else:
                for i in range(nmsgs):
                    msg = msgs[i + nsentmsgs]
                    bmmsg = bmmsgs[i]
                    if msg.is_extended_id:
                        bmmsg.mid.SID = msg.arbitration_id >> 18
                        bmmsg.mid.EID = (msg.arbitration_id & 0x3FFFF)
                    else:
                        bmmsg.mid.SID = msg.arbitration_id
                        bmmsg.mid.EID = 0
                    bmmsg.ctrl.tx.IDE = 1 if msg.is_extended_id else 0
                    bmmsg.ctrl.tx.FDF = 1 if msg.is_fd else 0
                    bmmsg.ctrl.tx.BRS = 1 if msg.bitrate_switch else 0
                    bmmsg.ctrl.tx.RTR = 1 if msg.is_remote_frame else 0
                    bmmsg.ctrl.tx.ESI = 1 if msg.error_state_indicator else 0
                    bmmsg.ctrl.tx.DLC = len2dlc(msg.dlc)
                    bmmsg.payload[:len(msg.data)] = msg.data
            nbmmsgs = ctypes.c_uint32(nmsgs)
            try:
                if self._handle != None:
                    bmapi.BM_WriteMultipleCanMessage(self._handle, dataptr, ctypes.byref(nbmmsgs), nullptr, timeoutms, nullptr)
                else:
                    self.recover_from_error()
            except BmError as e:
                    self.recover_from_error()

            nsentmsgs += nmsgs
            
    def cancel_send(self):
        bmapi.BM_CancelWrite(self._handle)

    def clear_buffer(self):
        with self._lock:
            bmapi.BM_ClearBuffer(self._handle)  

    def open_channel(self):
        self._handle = bmapi.BM_ChannelHandle()
        try:
            bmapi.BM_OpenEx(
            ctypes.byref(self._handle), 
            ctypes.byref(self._channelinfo), 
            self._mode, 
            self._tres, 
            ctypes.byref(self._bitrate), 
            ctypes.cast(ctypes.c_void_p(), ctypes.POINTER(bmapi.BM_RxFilterListTypeDef)), 0
            )
        except BmError as e:
                self._handle = None

    def shutdown(self):
        self.bus_list.remove(self)
        if self._handle:
            bmapi.BM_Close(self._handle)
        self._handle = bmapi.BM_ChannelHandle()

        
    def reset(self):
        bmapi.BM_Reset(self._handle)

    @property
    def state(self):
        return self._state

    @state.setter
    def state(self, new_state):
        mode_changed = False
        self._state = new_state
        if new_state is BusState.ACTIVE:
            if self._mode == bmapi.BM_CAN_OFF_MODE or self._mode == bmapi.BM_CAN_LISTEN_ONLY_MODE:
                self._mode = bmapi.BM_CAN_NORMAL_MODE
                mode_changed = True
            else:
                pass # Do not change (i.e. loopback)
        elif new_state is BusState.PASSIVE:
            # When this mode is set, the CAN controller does not take part on active events (eg. transmit CAN messages)
            # but stays in a passive mode (CAN monitor), in which it can analyse the traffic on the CAN bus used by a BMCAN channel.
            if self._mode != bmapi.BM_CAN_LISTEN_ONLY_MODE:
                self._mode = bmapi.BM_CAN_LISTEN_ONLY_MODE
                mode_changed = True
        if mode_changed:
            bmapi.BM_SetCanMode(self._handle, self._mode)

    @classmethod
    def enumerate(cls):
        BmCanBus.__init_class__()
        infolist = bmapi.BM_ChannelInfoListTypeDef()
        numOfInfo = ctypes.c_int(len(infolist.entries))
        bmapi.BM_EnumerateByCap(ctypes.byref(infolist), ctypes.byref(numOfInfo), bmapi.BM_CAN_CAP)
        channellist = []
        for i in range(numOfInfo.value):
            channellist.append({
                'index': i,
                'name': infolist.entries[i].name.decode(),
                # Add other exports here
            })
        return channellist
    
    def recover_from_error(self):
        # // Note: It takes some time to run BM_Close and BM_OpenEx, 
	    # // and channel handles will be invalidated when recovering from error,
	    # // make sure no other threads are using channel handles (e.g. calling BM_Write) during the recovery,
	    # // or, use single-threaded design, just like this demo.
        current_time = time.time()
        if (current_time - self._previous_recovery_ts) >= 1:
            canStatus = bmapi.BM_CanStatusInfoTypedef()
            canTes = bmapi.BM_TerminalResistorTypeDef()
            canBitrate = bmapi.BM_BitrateTypeDef()
            with self._lock:
                try:
                    status = bmapi.BM_GetStatus(self._handle, ctypes.byref(canStatus))
                    oldmode = bmapi.BM_CanModeTypeDef()
                    bmapi.BM_GetCanMode(self._handle, ctypes.byref(oldmode))
                    bmapi.BM_GetTerminalRegister(self._handle, ctypes.byref(canTes))
                    bmapi.BM_GetBitrate(self._handle, ctypes.byref(canBitrate))
                except Exception as e:
                    if self._debug:
                        self._log.error(f"{self.channel_info} 执行CAN配置时出错1: {str(e)}")
            if self._debug:
                self._log.info(
                    "=== Channel: %s - [Before busoff recovery] ===\n"
                    "  TXBO: %d (Transmit Bus Off)    | TXBP: %d (Transmit Bus Passive)\n"
                    "  RXBP: %d (Receive Bus Passive)  | TXWARN: %d (Transmit Warning)\n"
                    "  RXWARN: %d (Receive Warning)  | TEC: %d (Transmit Error Counter)\n"
                    "  REC: %d (Receive Error Counter)",
                    self.channel_info,
                    canStatus.TXBO, canStatus.TXBP,
                    canStatus.RXBP, canStatus.TXWARN,
                    canStatus.RXWARN, canStatus.TEC,
                    canStatus.REC
                )
                self._log.info(
                    "=== Channel: %s - [Before busoff recovery] ===\n"
                    "  status = %d\n",
                    self.channel_info,
                    status, 
                )	
                self._log.info(
                    "=== Channel: %s - [Before busoff recovery - Config] ===\n"
                    "  CAN Mode: 0x%02X | Terminal Resistor: 0x%04X\n"
                    "  Nominal Bitrate: %d kbps | Data Bitrate: %d kbps\n"
                    "  Nominal Sample Pos: %d%% | Data Sample Pos: %d%%",
                    self.channel_info,
                    oldmode.value, canTes.value,
                    canBitrate.nbitrate, canBitrate.dbitrate,
                    canBitrate.nsamplepos, canBitrate.dsamplepos
                )
            if (status & bmapi.BM_ERROR_INITIALIZE):
                # // BM_Init() is not called yet.
			    # // Read our SDK documentation for details. 
                print("BM_ERROR_INITIALIZE\n")
            elif (status & bmapi.BM_ERROR_ILLPARAMVAL):
                # // Channel handle is invalid. 
			    # // Maybe it's not opened yet (using BM_OpenEx) or already closed?
                print("BM_ERROR_ILLPARAMVAL\n")
                self._previous_recovery_ts = current_time
                for i in range(len(self.bus_list)):
                    bus = self.bus_list[i]
                    if bus._handle == None:
                        if (bytes(self._channelinfo.sn) == bytes(bus._channelinfo.sn) and bytes(self._channelinfo.uid) == bytes(bus._channelinfo.uid)):
                            bus.open_channel()
            elif (status & bmapi.BM_ERROR_ILLOPERATION):
                # // USB Device operation failed. 
			    # // Maybe the device is unplugged from host PC?
                print("BM_ERROR_ILLOPERATION\n")
                self._previous_recovery_ts = current_time
                # // Close all channels in the same device.
                try:
                    for i in range(len(self.bus_list)):
                        bus = self.bus_list[i]
                        if bus._handle != None:
                            if (bytes(self._channelinfo.sn) == bytes(bus._channelinfo.sn) and bytes(self._channelinfo.uid) == bytes(bus._channelinfo.uid)):
                                bmapi.BM_Close(bus._handle)
                                bus._handle = None
                # // Try reset device and remove device from opened device list kept by bmapi.
                    for i in range(len(self.bus_list)):
                        bus = self.bus_list[i]
                    if bus._handle == None:
                        if (bytes(self._channelinfo.sn) == bytes(bus._channelinfo.sn) and bytes(self._channelinfo.uid) == bytes(bus._channelinfo.uid)):
                            bus.open_channel()
                except Exception as e:
                    if self._debug:
                        self._log.error(f"{self.channel_info} 执行CAN配置时出错status & bmapi.BM_ERROR_ILLOPERATION: {str(e)}")
            elif ((status & bmapi.BM_ERROR_BUSOFF) or (status & bmapi.BM_ERROR_BUSPASSIVE) or (status & bmapi.BM_ERROR_BUSLIGHT)):
                # // BUSOFF
			    # // Maybe the remote CAN device is disconnected,
			    # // or you might want to check your bitrate, sample-position, tres configuration.
                if self._debug:
                    self._log.info("%sBUSOFF RECOVERY",self.channel_info)
                else:
	                print("BUSOFF RECOVERY\n")
                self._previous_recovery_ts = current_time
                # // Sometimes BUSOFF might be reported from a good channel.
			    # // We only perform BUSOFF recovery on the channels that are reported to have tx problems (e.g. tx timeout).
                oldmode = bmapi.BM_CanModeTypeDef()
                with self._lock:
                    try:
                        bmapi.BM_GetCanMode(self._handle, ctypes.byref(oldmode))

                        bmapi.BM_SetCanMode(self._handle, bmapi.BM_CAN_INTERNAL_LOOPBACK_MODE)
                    except Exception as e:
                        if self._debug:
                            self._log.error(f"{self.channel_info} 执行CAN配置时出错: {str(e)}")
    
                    dummyMessages = (bmapi.BM_CanMessageTypeDef * 256)()
                    for k in range(256):
                        dummyMessages[k].ctrl.tx.DLC = 1;

                    nmessages = ctypes.c_uint32(256)
                    try:
                        bmapi.BM_WriteMultipleCanMessage(
                        self._handle,
                        dummyMessages,
                        ctypes.byref(nmessages),
                        None,
                        1000,
                        None)
                    except Exception as e:
                        if self._debug:
                            self._log.error(f"{self.channel_info} 执行CAN配置时出错: {str(e)}")
                        try:
                            bmapi.BM_SetTerminalRegister(self._handle, self._tres)
                            bmapi.BM_SetBitrate(self._handle, self._bitrate)
                            bmapi.BM_SetCanMode(self._handle, oldmode.value)
                            bmapi.BM_ClearBuffer(self._handle)
                        except Exception as e:
                            if self._debug:
                                self._log.error(f"{self.channel_info} 执行CAN配置时出错: {str(e)}")
                with self._lock:
                    try:
                        bmapi.BM_SetTerminalRegister(self._handle, self._tres)
                        bmapi.BM_SetBitrate(self._handle, self._bitrate)
                        bmapi.BM_SetCanMode(self._handle, oldmode.value)
                        bmapi.BM_ClearBuffer(self._handle)
                        status = bmapi.BM_GetStatus(self._handle, ctypes.byref(canStatus))
                    except Exception as e:
                            if self._debug:
                                self._log.error(f"{self.channel_info} 执行CAN配置时出错 with self._lock11: {str(e)}")

                    if self._debug:
                        self._log.info(
                            "=== Channel: %s - [After busoff recovery] ===\n"
                            "  TXBO: %d (Transmit Bus Off)    | TXBP: %d (Transmit Bus Passive)\n"
                            "  RXBP: %d (Receive Bus Passive)  | TXWARN: %d (Transmit Warning)\n"
                            "  RXWARN: %d (Receive Warning)  | TEC: %d (Transmit Error Counter)\n"
                            "  REC: %d (Receive Error Counter)",
                            self.channel_info,
                            canStatus.TXBO, canStatus.TXBP,
                            canStatus.RXBP, canStatus.TXWARN,
                            canStatus.RXWARN, canStatus.TEC,
                            canStatus.REC)
                        self._log.info(
                            "=== Channel: %s - [After busoff recovery - Config] ===\n"
                            "  CAN Mode: 0x%02X | Terminal Resistor: 0x%04X\n"
                            "  Nominal Bitrate: %d kbps | Data Bitrate: %d kbps\n"
                            "  Nominal Sample Pos: %d%% | Data Sample Pos: %d%%",
                            self.channel_info,
                            oldmode.value, canTes.value,
                            canBitrate.nbitrate, canBitrate.dbitrate,
                            canBitrate.nsamplepos, canBitrate.dsamplepos)
        
    def send_isotp(self, payload, timeout=-1):
        timeout_ms = int(timeout * 1000.0) if timeout >= 0 else -1
        try:
            if self._handle != None:
                bmapi.BM_WriteIsotp(self._handle, ctypes.c_char_p(payload), len(payload), timeout_ms, ctypes.byref(self._isotp_config))
            else:
                self.recover_from_error()
        except BmError as e:
            self.recover_from_error()

    def receive_isotp(self, timeout=-1, max_len=4095):
        timeout_ms = int(timeout * 1000.0) if timeout >= 0 else -1
        buf = ctypes.create_string_buffer(max_len)
        received_len = ctypes.c_uint32(len(buf))
        if self._handle != None:
            bmapi.BM_ReadIsotp(self._handle, buf, ctypes.byref(received_len), timeout_ms, ctypes.byref(self._isotp_config))
        else:
            self.recover_from_error()
        return bytes(buf[:received_len.value])

    def config_isotp(self, tester_msg_id, ecu_msg_id, mode=bmapi.BM_ISOTP_NORMAL_TESTER, **kwargs):
        self._isotp_config.mode = mode
        enable_fdf = kwargs.get('fd', False) or kwargs.get('fdf', False)
        enable_brs = kwargs.get('brs', enable_fdf)
        enable_ide = kwargs.get('ide', False) or tester_msg_id > 0x7FF or ecu_msg_id > 0x7FF
        dlc = kwargs.get('dlc', 0xF if enable_fdf else 0x8)
        testerMsg = self._isotp_config.testerDataTemplate.getCanMessage()
        testerMsg.ctrl.tx.FDF = enable_fdf
        testerMsg.ctrl.tx.BRS = enable_brs
        testerMsg.ctrl.tx.IDE = enable_ide
        testerMsg.ctrl.tx.DLC = dlc
        testerMsg.setMessageId(tester_msg_id)
        self._isotp_config.testerDataTemplate.setCanMessage(testerMsg)
        ecuMsg = self._isotp_config.ecuDataTemplate.getCanMessage()
        ecuMsg.ctrl.tx.FDF = enable_fdf
        ecuMsg.ctrl.tx.BRS = enable_brs
        ecuMsg.ctrl.tx.IDE = enable_ide
        ecuMsg.ctrl.tx.DLC = dlc
        ecuMsg.setMessageId(ecu_msg_id)
        self._isotp_config.ecuDataTemplate.setCanMessage(ecuMsg)
        padding = kwargs.get('padding', None)
        if padding is not None:
            self._isotp_config.paddingEnabled = 1
            self._isotp_config.paddingValue = ctypes.c_uint8(padding)
        else:
            self._isotp_config.paddingEnabled = 0
        # Note if dlc > 8, BMAPI would ignore 'longPduEnabled' and always enable longPdu
        self._isotp_config.longPduEnabled = kwargs.get('longpdu', False)
        self._isotp_config.functionalAddressingEnabled = kwargs.get('functional', False)
        ecuTimeout = kwargs.get('ecuTimeout', {})
        testerTimeout = kwargs.get('testerTimeout', {})
        self._isotp_config.ecuTimeout.a = ecuTimeout.get('a', 0)
        self._isotp_config.ecuTimeout.b = ecuTimeout.get('b', 0)
        self._isotp_config.ecuTimeout.c = ecuTimeout.get('c', 0)
        self._isotp_config.testerTimeout.a = testerTimeout.get('a', 0)
        # Test would wait for FC from ECU until 'testerTimeout.b' timeout occurs.
        self._isotp_config.testerTimeout.b = testerTimeout.get('b', 50)
        self._isotp_config.testerTimeout.c = testerTimeout.get('c', 0)