#
# Code to abstract the parsing of APM Dataflash log files, currently only used by the LogAnalyzer
#
# Initial code by Andrew Chapman (amchapman@gmail.com), 16th Jan 2014
#

# AP_FLAKE8_CLEAN

from __future__ import print_function, division

import bisect
import ctypes
import sys

import numpy
from VehicleType import VehicleType, VehicleTypeString


class Format(object):
    '''Data channel format as specified by the FMT lines in the log file'''

    def __init__(self, msgType, msgLen, name, types, labels):
        self.NAME = 'FMT'
        self.msgType = msgType
        self.msgLen = msgLen
        self.name = name
        self.types = types
        self.labels = labels.split(',')

    def __str__(self):
        return "%8s %s" % (self.name, repr(self.labels))

    @staticmethod
    def trycastToFormatType(value, valueType):
        """
        Using format characters from libraries/DataFlash/DataFlash.h to cast strings to basic python int/float/string
        types tries a cast, if it does not work, well, acceptable as the text logs do not match the format, e.g. MODE is
        expected to be int
        """
        try:
            if valueType in "fcCeELd":
                return float(value)
            elif valueType in "bBhHiIMQq":
                return int(value)
            elif valueType in "nNZ":
                return str(value)
        except ValueError:
            pass
        return value

    def to_class(self):
        members = dict(
            NAME=self.name,
            labels=self.labels[:],
        )

        fieldtypes = [i for i in self.types]
        fieldlabels = self.labels[:]

        # field access
        for (label, _type) in zip(fieldlabels, fieldtypes):

            def createproperty(name, format):
                # extra scope for variable sanity
                # scaling via _NAME and def NAME(self): return self._NAME / SCALE
                propertyname = name
                attributename = '_' + name
                p = property(
                    lambda x: getattr(x, attributename),
                    lambda x, v: setattr(x, attributename, Format.trycastToFormatType(v, format)),
                )
                members[propertyname] = p
                members[attributename] = None

            createproperty(label, _type)

        # repr shows all values but the header
        members['__repr__'] = lambda x: "<{cls} {data}>".format(
            cls=x.__class__.__name__, data=' '.join(["{}:{}".format(k, getattr(x, '_' + k)) for k in x.labels])
        )

        def init(a, *x):
            if len(x) != len(a.labels):
                raise ValueError("Invalid Length")
            for (l, v) in zip(a.labels, x):
                try:
                    setattr(a, l, v)
                except Exception as e:
                    print("{} {} {} failed".format(a, l, v))
                    print(e)

        members['__init__'] = init

        # finally, create the class
        cls = type('Log__{:s}'.format(self.name), (object,), members)
        return cls


class logheader(ctypes.LittleEndianStructure):
    _fields_ = [
        ('head1', ctypes.c_uint8),
        ('head2', ctypes.c_uint8),
        ('msgid', ctypes.c_uint8),
    ]

    def __repr__(self):
        return "<logheader head1=0x{self.head1:x} head2=0x{self.head2:x} msgid=0x{self.msgid:x} ({self.msgid})>".format(
            self=self
        )


class BinaryFormat(ctypes.LittleEndianStructure):
    NAME = 'FMT'
    MSG = 128
    SIZE = 0
    FIELD_FORMAT = {
        'a': ctypes.c_int16 * 32,
        'b': ctypes.c_int8,
        'B': ctypes.c_uint8,
        'h': ctypes.c_int16,
        'H': ctypes.c_uint16,
        'i': ctypes.c_int32,
        'I': ctypes.c_uint32,
        'f': ctypes.c_float,
        'd': ctypes.c_double,
        'n': ctypes.c_char * 4,
        'N': ctypes.c_char * 16,
        'Z': ctypes.c_char * 64,
        'c': ctypes.c_int16,  # * 100,
        'C': ctypes.c_uint16,  # * 100,
        'e': ctypes.c_int32,  # * 100,
        'E': ctypes.c_uint32,  # * 100,
        'L': ctypes.c_int32,
        'M': ctypes.c_uint8,
        'q': ctypes.c_int64,
        'Q': ctypes.c_uint64,
    }

    FIELD_SCALE = {
        'c': 100,
        'C': 100,
        'e': 100,
        'E': 100,
    }

    _packed_ = True
    _fields_ = [
        ('head', logheader),
        ('type', ctypes.c_uint8),
        ('length', ctypes.c_uint8),
        ('name', ctypes.c_char * 4),
        ('types', ctypes.c_char * 16),
        ('labels', ctypes.c_char * 64),
    ]

    def __repr__(self):
        return "<{cls} {data}>".format(
            cls=self.__class__.__name__,
            data=' '.join(["{}:{}".format(k, getattr(self, k)) for (k, _) in self._fields_[1:]]),
        )

    def to_class(self):
        labels = self.labels.decode(encoding="utf-8") if self.labels else ""
        members = dict(
            NAME=self.name.decode(encoding="utf-8"),
            MSG=self.type,
            SIZE=self.length,
            labels=labels.split(","),
            _pack_=True,
        )

        if type(self.types[0]) == str:
            fieldtypes = [i for i in self.types]
        else:
            fieldtypes = [chr(i) for i in self.types]
        fieldlabels = members["labels"]
        if self.labels and (len(fieldtypes) != len(fieldlabels)):
            print("Broken FMT message for {} .. ignoring".format(self.name), file=sys.stderr)
            return None

        fields = [('head', logheader)]

        # field access
        for (label, _type) in zip(fieldlabels, fieldtypes):

            def createproperty(name, format):
                # extra scope for variable sanity
                # scaling via _NAME and def NAME(self): return self._NAME / SCALE
                propertyname = name
                attributename = '_' + name
                scale = BinaryFormat.FIELD_SCALE.get(format, None)

                def get_message_attribute(x):
                    ret = getattr(x, attributename)
                    if str(format) in ['Z', 'n', 'N']:
                        ret = ret.decode(encoding="utf-8")
                    return ret

                p = property(get_message_attribute)
                if scale is not None:
                    p = property(lambda x: getattr(x, attributename) / scale)
                members[propertyname] = p
                try:
                    fields.append((attributename, BinaryFormat.FIELD_FORMAT[format]))
                except KeyError:
                    print('ERROR: Failed to add FMT type: {}, with format: {}'.format(attributename, format))
                    raise

            createproperty(label, _type)
        members['_fields_'] = fields

        # repr shows all values but the header
        members['__repr__'] = lambda x: "<{cls} {data}>".format(
            cls=x.__class__.__name__, data=' '.join(["{}:{}".format(k, getattr(x, k)) for k in x.labels])
        )

        # finally, create the class
        cls = type('Log__%s' % self.name, (ctypes.LittleEndianStructure,), members)

        if ctypes.sizeof(cls) != cls.SIZE:
            print("size mismatch for {} expected {} got {}".format(cls, ctypes.sizeof(cls), cls.SIZE), file=sys.stderr)
            return None

        return cls


BinaryFormat.SIZE = ctypes.sizeof(BinaryFormat)


class Channel(object):
    '''storage for a single stream of data, i.e. all GPS.RelAlt values'''

    # TODO: rethink data storage, but do more thorough regression testing before refactoring it
    # TODO: store data as a scipy spline curve so we can more easily interpolate and sample the slope?

    def __init__(self):
        # store dupe data in dict and list for now, until we decide which is the better way to go
        self.dictData = {}  # dict of linenum->value
        self.listData = []  # list of (linenum,value)

    def getSegment(self, startLine, endLine):
        '''returns a segment of this data (from startLine to endLine, inclusive) as a new Channel instance'''
        segment = Channel()
        segment.dictData = {k: v for k, v in self.dictData.items() if k >= startLine and k <= endLine}
        segment.listData = [(k, v) for k, v in self.listData if k >= startLine and k <= endLine]
        return segment

    def min(self):
        return min(self.dictData.values())

    def max(self):
        return max(self.dictData.values())

    def avg(self):
        return numpy.mean(self.dictData.values())

    def getNearestValueFwd(self, lineNumber):
        '''Returns (value,lineNumber)'''
        index = bisect.bisect_left(self.listData, (lineNumber, -99999))
        while index < len(self.listData):
            line = self.listData[index][0]
            if line >= lineNumber:
                return (self.listData[index][1], line)
            index += 1
        raise ValueError("Error finding nearest value for line %d" % lineNumber)

    def getNearestValueBack(self, lineNumber):
        '''Returns (value,lineNumber)'''
        index = bisect.bisect_left(self.listData, (lineNumber, -99999)) - 1
        while index >= 0:
            line = self.listData[index][0]
            if line <= lineNumber:
                return (self.listData[index][1], line)
            index -= 1
        raise ValueError("Error finding nearest value for line %d" % lineNumber)

    def getNearestValue(self, lineNumber, lookForwards=True):
        """
        Find the nearest data value to the given lineNumber, defaults to first looking forwards.
        Returns (value,lineNumber)
        """
        if lookForwards:
            try:
                return self.getNearestValueFwd(lineNumber)
            except ValueError:
                return self.getNearestValueBack(lineNumber)
        else:
            try:
                return self.getNearestValueBack(lineNumber)
            except ValueError:
                return self.getNearestValueFwd(lineNumber)
        raise Exception("Error finding nearest value for line %d" % lineNumber)

    def getInterpolatedValue(self, lineNumber):
        (prevValue, prevValueLine) = self.getNearestValue(lineNumber, lookForwards=False)
        (nextValue, nextValueLine) = self.getNearestValue(lineNumber, lookForwards=True)
        if prevValueLine == nextValueLine:
            return prevValue
        weight = (lineNumber - prevValueLine) / float(nextValueLine - prevValueLine)
        return (weight * prevValue) + ((1 - weight) * nextValue)

    def getIndexOf(self, lineNumber):
        '''returns the index within this channel's listData of the given lineNumber, or raises an Exception if not found'''
        index = bisect.bisect_left(self.listData, (lineNumber, -99999))
        if self.listData[index][0] == lineNumber:
            return index
        else:
            raise Exception("Error finding index for line %d" % lineNumber)


class LogIterator:
    """
    Smart iterator that can move through a log by line number and maintain an index into the nearest values of all data
    channels
    """

    # TODO: LogIterator currently indexes the next available value rather than the nearest value, we should make it
    # configurable between next/nearest

    class LogIteratorSubValue:
        '''syntactic sugar to allow access by LogIterator[lineLabel][dataLabel]'''

        logdata = None
        iterators = None
        lineLabel = None

        def __init__(self, logdata, iterators, lineLabel):
            self.logdata = logdata
            self.lineLabel = lineLabel
            self.iterators = iterators

        def __getitem__(self, dataLabel):
            index = self.iterators[self.lineLabel][0]
            return self.logdata.channels[self.lineLabel][dataLabel].listData[index][1]

    iterators = {}  # lineLabel -> (listIndex,lineNumber)
    logdata = None
    currentLine = None

    def __init__(self, logdata, lineNumber=0):
        self.logdata = logdata
        self.currentLine = lineNumber
        for lineLabel in self.logdata.formats:
            if lineLabel in self.logdata.channels:
                self.iterators[lineLabel] = ()
        self.jump(lineNumber)

    def __iter__(self):
        return self

    def __getitem__(self, lineLabel):
        return LogIterator.LogIteratorSubValue(self.logdata, self.iterators, lineLabel)

    def next(self):
        '''increment iterator to next log line'''
        self.currentLine += 1
        if self.currentLine > self.logdata.lineCount:
            return self
        for lineLabel in self.iterators.keys():
            # check if the currentLine has gone past our the line we're pointing to for this type of data
            dataLabel = self.logdata.formats[lineLabel].labels[0]
            (index, lineNumber) = self.iterators[lineLabel]
            # if so, and it is not the last entry in the log, increment the indices for dataLabels under that lineLabel
            if (self.currentLine > lineNumber) and (
                index < len(self.logdata.channels[lineLabel][dataLabel].listData) - 1
            ):
                index += 1
                lineNumber = self.logdata.channels[lineLabel][dataLabel].listData[index][0]
                self.iterators[lineLabel] = (index, lineNumber)
        return self

    __next__ = next

    def jump(self, lineNumber):
        '''jump iterator to specified log line'''
        self.currentLine = lineNumber
        for lineLabel in self.iterators.keys():
            dataLabel = self.logdata.formats[lineLabel].labels[0]
            (value, lineNumber) = self.logdata.channels[lineLabel][dataLabel].getNearestValue(self.currentLine)
            self.iterators[lineLabel] = (self.logdata.channels[lineLabel][dataLabel].getIndexOf(lineNumber), lineNumber)


class DataflashLogHelper:
    '''helper functions for dealing with log data, put here to keep DataflashLog class as a simple parser and data store'''

    @staticmethod
    def getTimeAtLine(logdata, lineNumber):
        '''returns the nearest GPS timestamp in milliseconds after the given line number'''
        if "GPS" not in logdata.channels:
            raise Exception("no GPS log data found")
        # older logs use 'TIme', newer logs use 'TimeMS'
        # even newer logs use TimeUS
        timeLabel = None
        for possible in "TimeMS", "Time", "TimeUS":
            if possible in logdata.channels["GPS"]:
                timeLabel = possible
                break
        if timeLabel is None:
            raise Exception("Unable to get time label")
        while lineNumber <= logdata.lineCount:
            if lineNumber in logdata.channels["GPS"][timeLabel].dictData:
                return logdata.channels["GPS"][timeLabel].dictData[lineNumber]
            lineNumber = lineNumber + 1

        sys.stderr.write("didn't find GPS data for " + str(lineNumber) + " - using maxtime\n")
        return logdata.channels["GPS"][timeLabel].max()

    @staticmethod
    def findLoiterChunks(logdata, minLengthSeconds=0, noRCInputs=True):
        """
        Returns a list of (to, from) pairs defining sections of the log which are in loiter mode, ordered from longest
        to shortest in time. If `noRCInputs == True` it only returns chunks with no control inputs
        """
        # TODO: implement noRCInputs handling when identifying stable loiter chunks, for now we're ignoring it

        def chunkSizeCompare(chunk1, chunk2):
            chunk1Len = chunk1[1] - chunk1[0]
            chunk2Len = chunk2[1] - chunk2[0]
            if chunk1Len == chunk2Len:
                return 0
            elif chunk1Len > chunk2Len:
                return -1
            else:
                return 1

        changes = [{"line": k, "modeName": v[0], "modeNum": v[1]} for k, v in sorted(logdata.modeChanges.items())]
        chunks = []
        for i in range(len(changes)):
            if changes[i]["modeName"] == "LOITER":
                startLine = changes[i]["line"]
                try:
                    endLine = changes[i + 1]["line"]
                except IndexError:
                    endLine = logdata.lineCount
                chunkTimeSeconds = (
                    DataflashLogHelper.getTimeAtLine(logdata, endLine)
                    - DataflashLogHelper.getTimeAtLine(logdata, startLine)
                    + 1
                ) / 1000.0
                if chunkTimeSeconds > minLengthSeconds:
                    chunks.append((startLine, endLine))
        chunks.sort(key=lambda chunk: chunk[1] - chunk[0])
        return chunks

    @staticmethod
    def isLogEmpty(logdata):
        '''returns an human readable error string if the log is essentially empty, otherwise returns None'''
        # naive check for now, see if the throttle output was ever above 20%
        throttleThreshold = 20
        if logdata.vehicleType == VehicleType.Copter:
            throttleThreshold = 200  # copter uses 0-1000, plane+rover use 0-100
        if "CTUN" in logdata.channels:
            try:
                maxThrottle = logdata.channels["CTUN"]["ThrOut"].max()
            except KeyError:
                # ThrOut was shorted to ThO at some stage...
                maxThrottle = logdata.channels["CTUN"]["ThO"].max()
                # at roughly the same time ThO became a range from 0 to 1
                throttleThreshold = 0.2
            if maxThrottle < throttleThreshold:
                return "Throttle never above 20%"
        return None


class DataflashLog(object):
    """
    ArduPilot Dataflash log file reader and container class. Keep this simple, add more advanced or specific functions
    to DataflashLogHelper class
    """

    knownHardwareTypes = ["APM", "PX4", "MPNG"]

    def __init__(self, logfile=None, format="auto", ignoreBadlines=False):
        self.filename = None

        self.vehicleType = None  # from VehicleType enumeration; value derived from header
        self.vehicleTypeString = None  # set at same time has the enum value
        self.firmwareVersion = ""
        self.firmwareHash = ""
        self.freeRAM = 0
        self.hardwareType = ""  # APM 1, APM 2, PX4, MPNG, etc What is VRBrain? BeagleBone, etc? Needs more testing

        self.formats = {}  # name -> Format
        self.parameters = {}  # token -> value
        self.messages = {}  # lineNum -> message
        self.modeChanges = {}  # lineNum -> (mode,value)
        self.channels = {}  # lineLabel -> {dataLabel:Channel}

        self.filesizeKB = 0
        self.durationSecs = 0
        self.lineCount = 0
        self.skippedLines = 0
        self.backpatch_these_modechanges = []
        self.frame = None

        if logfile:
            self.read(logfile, format, ignoreBadlines)

    def getCopterType(self):
        '''returns quad/hex/octo/tradheli if this is a copter log'''
        if self.vehicleType != VehicleType.Copter:
            return None
        motLabels = []
        if "MOT" in self.formats:  # not listed in PX4 log header for some reason?
            motLabels = self.formats["MOT"].labels
        if "GGain" in motLabels:
            return "tradheli"
        elif len(motLabels) == 4:
            return "quad"
        elif len(motLabels) == 6:
            return "hex"
        elif len(motLabels) == 8:
            return "octo"
        else:
            return ""

    def num_motor_channels(self):
        motor_channels_for_frame = {
            "QUAD": 4,
            "HEXA": 6,
            "Y6": 6,
            "OCTA": 8,
            "OCTA_QUAD": 8,
            "DECA": 10,
            #            "HELI": 1,
            #            "HELI_DUAL": 2,
            "TRI": 3,
            "SINGLE": 1,
            "COAX": 2,
            "TAILSITTER": 1,
            "DODECA_HEXA": 12,
        }
        return motor_channels_for_frame[self.frame]

    def read(self, logfile, format="auto", ignoreBadlines=False):
        '''returns on successful log read (including bad lines if ignoreBadlines==True), will throw an Exception otherwise'''
        # TODO: dataflash log parsing code is pretty hacky, should re-write more methodically
        df_header = bytearray([0xA3, 0x95, 0x80, 0x80])
        self.filename = logfile
        if self.filename == '<stdin>':
            f = sys.stdin
        else:
            f = open(self.filename, 'rb')

        if format.lower() == 'bin':
            head = df_header
        elif format == 'log':
            head = ""
        elif format == 'auto':
            if self.filename == '<stdin>':
                # assuming TXT format
                head = ""
            else:
                head = f.read(4)
                f.seek(0)
        else:
            raise ValueError("Unknown log format for {}: {}".format(self.filename, format))

        if head == df_header:
            numBytes, lineNumber = self.read_binary(f, ignoreBadlines)
            pass
        else:
            numBytes, lineNumber = self.read_text(f, ignoreBadlines)

        # gather some general stats about the log
        self.lineCount = lineNumber
        self.filesizeKB = numBytes / 1024.0
        # TODO: switch duration calculation to use TimeMS values rather than GPS timestemp
        if "GPS" in self.channels:
            # the GPS time label changed at some point, need to handle both
            timeLabel = None
            for i in 'TimeMS', 'TimeUS', 'Time':
                if i in self.channels["GPS"]:
                    timeLabel = i
                    break
            firstTimeGPS = int(self.channels["GPS"][timeLabel].listData[0][1])
            lastTimeGPS = int(self.channels["GPS"][timeLabel].listData[-1][1])
            if timeLabel == 'TimeUS':
                firstTimeGPS /= 1000
                lastTimeGPS /= 1000
            self.durationSecs = (lastTimeGPS - firstTimeGPS) / 1000

        # TODO: calculate logging rate based on timestamps
        # ...

    msg_vehicle_to_vehicle_map = {
        "ArduCopter": VehicleType.Copter,
        "APM:Copter": VehicleType.Copter,
        "ArduPlane": VehicleType.Plane,
        "ArduRover": VehicleType.Rover,
    }

    # takes the vehicle type supplied via "MSG" and sets vehicleType from
    # the VehicleType enumeration
    def set_vehicleType_from_MSG_vehicle(self, MSG_vehicle):
        ret = self.msg_vehicle_to_vehicle_map.get(MSG_vehicle, None)
        if ret is None:
            raise ValueError("Unknown vehicle type (%s)" % (MSG_vehicle))
        self.vehicleType = ret
        self.vehicleTypeString = VehicleTypeString[ret]

    def handleModeChange(self, lineNumber, e):
        if self.vehicleType == VehicleType.Copter:
            modes = {
                0: 'STABILIZE',
                1: 'ACRO',
                2: 'ALT_HOLD',
                3: 'AUTO',
                4: 'GUIDED',
                5: 'LOITER',
                6: 'RTL',
                7: 'CIRCLE',
                9: 'LAND',
                10: 'OF_LOITER',
                11: 'DRIFT',
                13: 'SPORT',
                14: 'FLIP',
                15: 'AUTOTUNE',
                16: 'POSHOLD',
                17: 'BRAKE',
                18: 'THROW',
                19: 'AVOID_ADSB',
                20: 'GUIDED_NOGPS',
                21: 'SMART_RTL',
            }
            try:
                if hasattr(e, 'ThrCrs'):
                    self.modeChanges[lineNumber] = (modes[int(e.Mode)], e.ThrCrs)
                else:
                    # assume it has ModeNum:
                    self.modeChanges[lineNumber] = (modes[int(e.Mode)], e.ModeNum)
            except ValueError:
                if hasattr(e, 'ThrCrs'):
                    self.modeChanges[lineNumber] = (e.Mode, e.ThrCrs)
                else:
                    # some .log files have the name spelt out by name
                    # rather than number, contrary to the format
                    # string.  Attempt to map that back to a number:
                    uppername = str(e.Mode).upper()
                    for num in modes:
                        if modes[num].upper() == uppername:
                            self.modeChanges[lineNumber] = (uppername, num)
                            return
                    # assume it has ModeNum:
                    print("Unknown mode=%u" % e.ModeNum)
                    self.modeChanges[lineNumber] = (e.Mode, "mode=%u" % e.ModeNum)
        elif self.vehicleType in [VehicleType.Plane, VehicleType.Copter, VehicleType.Rover]:
            self.modeChanges[lineNumber] = (e.Mode, e.ModeNum)
        else:
            # if you've gotten to here the chances are we don't
            # know what vehicle you're flying...
            raise Exception(
                "Unknown log type for MODE line vehicletype=({}) line=({})".format(self.vehicleTypeString, repr(e))
            )

    def backPatchModeChanges(self):
        for (lineNumber, e) in self.backpatch_these_modechanges:
            self.handleModeChange(lineNumber, e)

    def set_frame(self, frame):
        self.frame = frame

    def process(self, lineNumber, e):
        if e.NAME == 'FMT':
            cls = e.to_class()
            if cls is not None:  # FMT messages can be broken ...
                if hasattr(e, 'type') and e.type not in self._formats:  # binary log specific
                    self._formats[e.type] = cls
                if cls.NAME not in self.formats:
                    self.formats[cls.NAME] = cls
        elif e.NAME == "PARM":
            self.parameters[e.Name] = e.Value
        elif e.NAME == "MSG":
            tokens = e.Message.split(' ')
            if not self.frame:
                if "Frame" in tokens[0]:
                    self.set_frame(tokens[1])
            if not self.vehicleType:
                try:
                    self.set_vehicleType_from_MSG_vehicle(tokens[0])
                except ValueError:
                    return
                self.backPatchModeChanges()
                self.firmwareVersion = tokens[1]
                if len(tokens) == 3:
                    self.firmwareHash = tokens[2][1:-1]
            else:
                self.messages[lineNumber] = e.Message
        elif e.NAME == "MODE":
            if self.vehicleType is None:
                self.backpatch_these_modechanges.append((lineNumber, e))
            else:
                self.handleModeChange(lineNumber, e)
        # anything else must be the log data
        else:
            groupName = e.NAME

            # first time seeing this type of log line, create the channel storage
            if groupName not in self.channels:
                self.channels[groupName] = {}
                for label in e.labels:
                    self.channels[groupName][label] = Channel()

            # store each token in its relevant channel
            for label in e.labels:
                value = getattr(e, label)
                channel = self.channels[groupName][label]
                channel.dictData[lineNumber] = value
                channel.listData.append((lineNumber, value))

    def read_text(self, f, ignoreBadlines):
        self.formats = {'FMT': Format}
        lineNumber = 0
        numBytes = 0
        knownHardwareTypes = ["APM", "PX4", "MPNG"]
        for line in f:
            lineNumber = lineNumber + 1
            numBytes += len(line) + 1
            line = line.decode(encoding="utf-8")
            try:
                line = line.strip('\n\r')
                tokens = line.split(', ')
                # first handle the log header lines
                if line == " Ready to drive." or line == " Ready to FLY.":
                    continue
                if line == "----------------------------------------":  # present in pre-3.0 logs
                    raise Exception(
                        "Log file seems to be in the older format (prior to self-describing logs), which isn't supported"
                    )
                if len(tokens) == 1:
                    tokens2 = line.split(' ')
                    if line == "":
                        pass
                    elif len(tokens2) == 1 and tokens2[0].isdigit():  # log index
                        pass
                    elif len(tokens2) == 3 and tokens2[0] == "Free" and tokens2[1] == "RAM:":
                        self.freeRAM = int(tokens2[2])
                    elif tokens2[0] in knownHardwareTypes:
                        # not sure if we can parse this more usefully, for now only need to report it back verbatim
                        self.hardwareType = line
                    elif (len(tokens2) == 2 or len(tokens2) == 3) and tokens2[1][
                        0
                    ].lower() == "v":  # e.g. ArduCopter V3.1 (5c6503e2)
                        try:
                            self.set_vehicleType_from_MSG_vehicle(tokens2[0])
                        except ValueError:
                            pass
                        self.firmwareVersion = tokens2[1]
                        if len(tokens2) == 3:
                            self.firmwareHash = tokens2[2][1:-1]
                    else:
                        errorMsg = "Error parsing line %d of log file: %s" % (lineNumber, self.filename)
                        if ignoreBadlines:
                            print(errorMsg + " (skipping line)", file=sys.stderr)
                            self.skippedLines += 1
                        else:
                            raise Exception("")
                else:
                    if not tokens[0] in self.formats:
                        raise ValueError("Unknown Format {}".format(tokens[0]))
                    e = self.formats[tokens[0]](*tokens[1:])
                    self.process(lineNumber, e)
            except Exception as e:
                print("BAD LINE: " + str(line), file=sys.stderr)
                if not ignoreBadlines:
                    raise Exception(
                        "Error parsing line %d of log file %s - %s" % (lineNumber, self.filename, e.args[0])
                    )
        return (numBytes, lineNumber)

    def read_binary(self, f, ignoreBadlines):
        lineNumber = 0
        numBytes = 0
        for e in self._read_binary(f, ignoreBadlines):
            lineNumber += 1
            if e is None:
                continue
            numBytes += e.SIZE
            #            print(e)
            self.process(lineNumber, e)
        return (numBytes, lineNumber)

    def _read_binary(self, f, ignoreBadlines):
        self._formats = {128: BinaryFormat}
        data = bytearray(f.read())
        offset = 0
        while len(data) > offset + ctypes.sizeof(logheader):
            h = logheader.from_buffer(data, offset)
            if not (h.head1 == 0xA3 and h.head2 == 0x95):
                if ignoreBadlines is False:
                    raise ValueError(h)
                else:
                    if h.head1 == 0xFF and h.head2 == 0xFF and h.msgid == 0xFF:
                        print(
                            "Assuming EOF due to dataflash block tail filled with \\xff... (offset={off})".format(
                                off=offset
                            ),
                            file=sys.stderr,
                        )
                        break
                    offset += 1
                    continue

            if h.msgid in self._formats:
                typ = self._formats[h.msgid]
                if len(data) <= offset + typ.SIZE:
                    break
                try:
                    e = typ.from_buffer(data, offset)
                except ValueError:
                    print(
                        "data:{} offset:{} size:{} sizeof:{} sum:{}".format(
                            len(data), offset, typ.SIZE, ctypes.sizeof(typ), offset + typ.SIZE
                        )
                    )
                    raise
                offset += typ.SIZE
            else:
                raise ValueError(str(h) + "unknown type")
            yield e