#!/usr/bin/env python

import curses
import time
import six
import copy
import argparse
import re
import threading
import serial

for pygcode_lib_type in ('installed_lib', 'relative_lib'):
    try:
        # pygcode
        from pygcode import NullMachine
        from pygcode import GCodeRapidMove
        from pygcode import GCodeIncrementalDistanceMode
        from pygcode import text2gcodes

    except ImportError:
        import sys, os, inspect
        # Add pygcode (relative to this test-path) to the system path
        _this_path = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))
        sys.path.insert(0, os.path.join(_this_path, '..', 'src'))
        if pygcode_lib_type == 'installed_lib':
            continue # import was attempted before sys.path addition. retry import
        raise # otherwise the raised ImportError is a genuine problem
    break


class Widget(object):
    pass


class Label(Widget):
    def __init__(self, window, row, col, len, text='', prefix=''):
        self.window = window
        self.row = row
        self.col = col
        self.len = len
        self._text = text
        self.prefix = prefix
        self.render()

    def render(self):
        text = self._text + (' ' * max(0, self.len - len(self._text)))
        self.window.addstr(self.row, self.col, self.prefix + text)

    @property
    def text(self):
        return self._text

    @text.setter
    def text(self, val):
        self._text = val
        self.render()


class NumberLabel(Widget):
    def __init__(self, window, row, col, value=0.0):
        self.window = window
        self.row = row
        self.col = col
        self._value = value
        self.render()

    def render(self):
        val_text = "{:>8s}".format("{:.3f}".format(self.value))
        self.window.addstr(self.row, self.col, val_text)

    @property
    def value(self):
        return self._value

    @value.setter
    def value(self, v):
        self._value = v
        self.render()


class Button(Widget):
    def __init__(self, window, label, row, col):
        self.window = window
        self.label = label
        self.row = row
        self.col = col

        self.render()

    def flash(self):
        self.render(strong=True)
        self.window.refresh()
        time.sleep(0.1)
        self.render()
        self.window.refresh()

    def render(self, strong=False):
        addstr_params = [self.row, self.col, '[{}]'.format(self.label)]
        if strong:
            addstr_params.append(curses.A_BOLD)
        self.window.addstr(*addstr_params)


class Banner(Widget):
    label_col = 4 # <space>text<space>

    def __init__(self, window, label=None, row=0):
        self.window = window
        self._label = label
        self.row = row
        self.render()

    def render(self, strong=False):
        (y, x) = self.window.getmaxyx()
        label_str = " {} ".format(self._label)
        hline_params = [0, 0, curses.ACS_HLINE, x]
        addstr_params = [self.row, self.label_col, " {} ".format(self._label)]
        if strong:
            hline_params.append(curses.A_BOLD)
            addstr_params.append(curses.A_BOLD)

        self.window.hline(*hline_params)
        self.window.addstr(*addstr_params)

    @property
    def label(self):
        return self._label

    @label.setter
    def label(self, value):
        self._label = value
        self.render()


class Status(object):
    row = 0
    banner_prefix = 'Status: '

    def __init__(self, screen):
        self.screen = screen
        (max_y, max_x) = self.screen.getmaxyx()
        self.window = curses.newwin(5, max_x, self.row, 0)
        self.status = ''
        self.banner = Banner(self.window, self.banner_prefix)


        # Print backdrop (to use as template)
        backdrop = [
            'Jog: [xxxx.yyy ]       MPos      WPos',
            '   [Y+]    [Z+]   X |xxxx.yyy |xxxx.yyy |   Feed Rate: ?',
            '[X-]  [X+]        Y |xxxx.yyy |xxxx.yyy |   Spindle:   ?',
            '   [Y-]    [Z-]   Z |xxxx.yyy |xxxx.yyy |   ',
        ]
        for (row, line) in enumerate(backdrop):
           self.window.addstr(row + 1, 0, line[:max_x])

        # Widgets
        self.widgets = {
            'X+': Button(self.window, 'X+', 3, 6),
            'X-': Button(self.window, 'X-', 3, 0),
            'Y+': Button(self.window, 'Y+', 2, 3),
            'Y-': Button(self.window, 'Y-', 4, 3),
            'Z+': Button(self.window, 'Z+', 2, 11),
            'Z-': Button(self.window, 'Z-', 4, 11),
            'jog': NumberLabel(self.window, 1, 6, 0.001),
            'MPosX': NumberLabel(self.window, 2, 21),
            'MPosY': NumberLabel(self.window, 3, 21),
            'MPosZ': NumberLabel(self.window, 4, 21),
            'WPosX': NumberLabel(self.window, 2, 31),
            'WPosY': NumberLabel(self.window, 3, 31),
            'WPosZ': NumberLabel(self.window, 4, 31),
            'feed_rate': Label(self.window, 2, 44, len=20, text='?', prefix='Feed Rate: '),
            'spindle': Label(self.window, 3, 44, len=20, text='?', prefix='Spindle:   '),
        }

        self.refresh()

    def set_status(self, status):
        self.status = status
        self.banner.label = "{prefix}{label}".format(
            prefix=self.banner_prefix,
            label=status,
        )
        self.refresh()

    @property
    def is_idle(self):
        return self.status == 'Idle'

    def refresh(self):
        self.window.refresh()


# Line types:
#   gcode:  <'>' if cur> <gcode> > <response>
#   info:   <'>' if cur> <info text>

class GCodeContent(object):
    def __init__(self, gcode, sent=False, status=''):
        self.gcode = gcode
        self.sent = sent
        self.status = status

    def to_str(self, width):
        gcode_w = max(0, width - 23)
        return ("{gcode:<%i.%is} {sent} {status:<20s}" % (gcode_w, gcode_w)).format(
            gcode=self.gcode,
            sent='>' if self.sent else ' ',
            status=self.status,
        )

class ConsoleLine(object):
    def __init__(self, window, content, cur=False):
        self.window = window
        self.content = content
        self._cur = cur
        self._width = 0
        self.update_width()

    def render(self, row):
        line = '> ' if self._cur else '  '
        if isinstance(self.content, GCodeContent):
            line += self.content.to_str(max(0, self._width - len(line)))
        else:
            line += str(self.content)
        line = ("{:%i.%is}" % (self._width-1,self._width-1)).format(line)
        self.window.addstr(row, 0, line)

    def update_width(self):
        (_, self._width) = self.window.getmaxyx()

    @property
    def cur(self):
        return self._cur

    @cur.setter
    def cur(self, value):
        self._cur = value


class AccordionWindow(object):
    """
    A region of the screen that can push those above and below it around.
    eg: as an active accordion window's content grows, it can push the window
    below it down, and make it smaller.
    """

    def __init__(self, screen, title, soft_height=2, min_height=0):
        self.screen = screen
        self.title = title
        self.soft_height = soft_height
        self.min_height = min_height

        self.focus = False
        self.lines = []  # list of ConsoleLine instances (first are at the top)

        self.window = None
        self.banner = None
        self.add_line_callback = None

    def init_window(self, row, height):
        self.window = curses.newwin(height, self.screen.getmaxyx()[1], row, 0)
        self.banner = Banner(self.window, self.title)

    def _add_line(self, line):
        i = len(self.lines)
        self.lines.append(line)
        if self.add_line_callback:
            self.add_line_callback(self)

    def move_window(self, row, height):
        self.window.resize(height, self.screen.getmaxyx()[1])
        self.window.mvwin(row, 0)
        #self.window.box()
        #self.window.addstr(0, 5, self.title)

    def render(self, active=False):
        #self.window.clear()  # FIXME: start fresh every render?, inefficient
        self.banner.render(strong=active)
        (rows, cols) = self.window.getmaxyx()
        if rows > 1: # we have room to render lines
            for (i, line) in enumerate(self.lines[-(rows - 1):]):
                line.render(i + 1)
        self.refresh()

    def __eq__(self, other):
        return self.title == other.title

    def refresh(self):
        self.window.refresh()

    def clear(self):
        self.lines = []
        self.window.clear()


class AccordionWindowManager(object):
    def __init__(self, screen, windows, header_height, footer_height=0):

        self.screen = screen
        self.windows = windows
        self.header_height = header_height
        self.footer_height = footer_height

        self._focus_index = 0

        self._log = []

        # Initialize accordion window's curses.Window instance
        def _add_line_cb(window):
            self.update_distrobution()
            window.render()

        cur_row = self.header_height
        for (i, window) in enumerate(self.windows):
            window.init_window(cur_row, window.soft_height)
            window.refresh()
            window.add_line_callback = _add_line_cb
            cur_row += window.min_height

    @property
    def focus(self):
        return self.windows[self._focus_index]

    @focus.setter
    def focus(self, value):
        self._focus_index = self.windows.index(value)
        self.update_distrobution()

    def update_distrobution(self):
        # rows available across space
        rows = self.screen.getmaxyx()[0] - (self.header_height + self.footer_height)
        min_occupied = sum(w.min_height for w in self.windows)
        available = rows - min_occupied
        if rows - min_occupied < 3:
            pass # TODO: not enough room to respect min_heights
        # focussed window height
        #   - self.focus.min_height
        #   - len(self.focus.lines) + 1
        #   - available + self.focus.min_height  # max available space
        extra_alocate = max(0, (len(self.focus.lines) + 1) - self.focus.min_height)
        height_f = min(available, extra_alocate) + self.focus.min_height
        available -= height_f - self.focus.min_height

        cur_row = self.header_height
        for w in self.windows:
            if w == self.focus:
                height = height_f
            else:
                extra_alocate = max(0, (len(w.lines) + 1) - w.min_height)
                height = min(available, extra_alocate) + w.min_height
                available -= height - w.min_height

            w.move_window(cur_row, height)
            w.render(active=True if w == self.focus else False)
            cur_row += height

        self.refresh()

    def refresh(self):
        for w in self.windows:
            w.refresh()


class InitWindow(AccordionWindow):
    def add_line(self, text):
        obj = ConsoleLine(self.window, text)
        self._add_line(obj)
        return obj


class JoggingWindow(AccordionWindow):
    def add_line(self, gcode, sent=False, status=''):
        obj = ConsoleLine(self.window, GCodeContent(
            gcode=gcode, sent=sent, status=status
        ))
        self._add_line(obj)
        return obj


class StreamWindow(AccordionWindow):
    def add_line(self, gcode, sent=False, status=''):
        obj = ConsoleLine(self.window, GCodeContent(
            gcode=gcode, sent=sent, status=status
        ))
        self._add_line(obj)
        return obj


JOGGING_VALUES = [
    0.001, 0.01, 0.1, 1, 10, 25, 50, 100, 250, 500
]

def jog_value(cur_val, dindex):
    try:
        i = JOGGING_VALUES.index(cur_val)
    except ValueError:
        i = 0
    i = max(0, min(i + dindex, len(JOGGING_VALUES) - 1))
    return JOGGING_VALUES[i]


# ---------------- Serial Utilities ---------------------

class SerialPort(object):
    def __init__(self, device, baudrate, logfilename=None):
        self.device = device
        self.baudrate = baudrate
        self.serial = serial.Serial(self.device, self.baudrate)
        self.logfilename = logfilename
        self.log = None

        self._cur_line = ''  # buffered line chars before '\n' received

        if self.logfilename:
            self.log = open(self.logfilename, 'w')

    def __del__(self):
        self.serial.close()
        if self.log:
            self.log.close()

    def _log_write(self, prefix, msg):
        if self.log:
            self.log.write("[{time:.2f}] {prefix} {msg}\n".format(
                time=time.time(),
                prefix=prefix,
                msg=msg.replace('\n', r'\n').replace('\r', r'\r'),
            ))

    def write(self, data):
        self._log_write('>>', data)
        self.serial.write(data)

    def readlines(self, timeout=None):
        start_time = time.time()
        orig_timeout = self.serial.timeout

        def _new_timeout():
            """Return linearly diminished timeout (with realtime)"""
            if timeout is None:
                return None
            cur_time = time.time()
            if cur_time - start_time >= timeout:
                return 0.0
            return timeout - (cur_time - start_time)

        while True:
            # Set read timeout
            time_remaining = _new_timeout()
            if time_remaining == 0:
                break
            self.serial.timeout = time_remaining

            # read
            # FIXME: char by char (a bit clunky, but easy to write)
            try:
                received_chr = self.serial.read()
            except serial.serialutil.SerialException:
                continue # terminal resize interrupts serial read
            self._cur_line += received_chr
            if self._cur_line.endswith('\n'):
                self._log_write('<<', self._cur_line)
                received_line = re.sub(r'\r?\n$', '', self._cur_line)
                self._cur_line = ''
                yield received_line

        self.serial.timeout = orig_timeout


class GCodeStreamException(Exception):
    """Raised when GRBL responds with error"""
    pass


class GCodeStreamer(object):
    # - keep track of GRBL buffer size
    # - transmit to GRBL
    # - read GRLB responses and delegate accordingly

    class Line(object):
        # - handle status & screen update
        #   - new
        #   - sent
        #   - received (status string) (raise exception if bad
        # - send
        #   - publish on screen
        # - set status
        #   - publish status on screen
        #   - report bad status back to streamer
        def __init__(self, gcode, widget=None):
            # verify parameter(s)
            if widget is not None:
                assert isinstance(widget, ConsoleLine), "bad widget type: %r" % widget
                assert isinstance(widget.content, GCodeContent), "bad widget content: %r" % widget.content

            # initialize
            self.gcode = gcode
            self.widget = widget


        def set_sent(self, value=True):
            if self.widget:
                self.widget.content.sent = value

        def set_status(self, msg):
            if self.widget:
                self.widget.content.status = msg

        def _normalized(self):
            return re.sub(r'\(.*?\)|;.*|\s', '', self.gcode).upper()

        def __str__(self):
            """
            :return: str to be sent over serial (including newline)
            """
            return self._normalized() + "\n"

        def __len__(self):
            return len(str(self))

        def __bool__(self):
            if self._normalized():
                return True
            return False

        __nonzero__ = __bool__  # python 2.x compatability


    DEFAULT_MAX_BUFFER = 128
    RESPONSE_REGEX = re.compile(r'^(?P<keyword>(ok|error))', re.I)

    def __init__(self, serial, max_buffer=None):
        assert isinstance(serial, SerialPort), "bad serial type: %r" % serial
        self.serial = serial
        self.max_buffer = max_buffer if max_buffer is not None else self.DEFAULT_MAX_BUFFER

        # --- Lines
        # Description:
        #    a moving window buffer of GCodeStreamer.Line instances sent to GRBL.
        #    this moving window stretches between:
        #       [0]  oldest sent gcode that has not yet received a GRBL response.
        #            once status is received, [0] is removed: self.sent_lines.pop(0)
        #       [-1] most recent gcode sent to GRBL device.
        self.sent_lines = []
        self.pending_lines = []

    def is_valid_response(self, response_msg):  # TODO: delete if not used
        """returns truthy: regex match if valid, None otherwise"""
        return self.RESPONSE_REGEX.search(response_msg)

    def process_response(self, response):
        """
        A response from GRBL is assumed to be to gcode at self.sent_lines[0]
        Once processed, the first of self.sent_lines is removed
        :param response: str received from GRBL device
        """
        match = self.RESPONSE_REGEX.search(response)
        if match:
            # Pop oldest line
            line = self.sent_lines.pop(0)
            line.set_status(response)
            if match.group('keyword').lower() == 'error':
                raise GCodeStreamException("error on gcode: '{gcode}' {msg}".format(
                    gcode=line.gcode,
                    msg=response
                ))

            # Send next line (if possible)
            self.poll_transmission()
        else:
            raise GCodeStreamException("unidentified message: %s" % response)

    def can_send(self, line):
        """
        Can the given line be transmitted?
        :return: True if line will not push GRBL's buffer over it's limit
        """
        assert isinstance(line, GCodeStreamer.Line)
        return (self.used_buffer + len(line)) <= self.max_buffer

    def send(self, line):
        """Add to pending lines, then poll transmission (once)"""
        assert isinstance(line, GCodeStreamer.Line)
        self.pending_lines.append(line)
        self.poll_transmission()

    def _transmit(self, line):
        assert isinstance(line, GCodeStreamer.Line)
        self.serial.write(str(line)) # Send to GRBL device

    def poll_transmission(self):
        """
        Send next line if there's enough room in GRBL's buffer.
        :return: True if there's data to transmit, False if it's all been sent
        """
        if not self.pending_lines:
            return False
        elif self.can_send(self.pending_lines[0]):
            line = self.pending_lines.pop(0)
            self._transmit(line)
            self.sent_lines.append(line) # Add to line buffer
            line.set_sent()
        return True

    @property
    def finished(self):
        if self.sent_lines or self.pending_lines:
            return False
        return True

    @property
    def used_buffer(self):
        return sum(len(l) for l in self.sent_lines)

    @property
    def pending_count(self):
        return len(self.pending_lines)


# ---------------- Arduino Util ---------------------
def arduino_comports():
    """
    List of serial comports serial numbers of Arduino boards connected to this machine
    :return: generator of comports connected to arduino
    """
    #for comport in arduino_comports():
    #    comport.serial_number # '55639303235351C071B0'
    #    comport.device # '/def/ttyACM0'
    from serial.tools.list_ports_posix import comports

    arduino_manufacturer_regex = re.compile(r'arduino', re.IGNORECASE) # simple, because I've only got one to test on
    for comport in comports():
        if comport.manufacturer:
            match = arduino_manufacturer_regex.search(comport.manufacturer)
            if match:
                yield comport


def device_type(value):
    # argparse type

    def _safe_comport_wrapper(key):
        # define comports list
        try:
            comports = [cp for cp in arduino_comports() if key(cp)]
        except Exception:
            print("ERROR: could not utilise serial library to find connected Arduino "
                  "(for given device: %s) just try the serial device (eg: /dev/ttyACM0)" % value)
            raise
        if len(comports) == 1:
            # exchange serial number for serial device Arduino is connected to
            return comports[0]
        else:
            raise argparse.ArgumentTypeError("could not find Arduino from '%s', just try the serial device (eg: /dev/ttyACM0)" % value)

    if value is None:
        comport = _safe_comport_wrapper(lambda cp: True) # all
        value = comport.device
    elif re.search(r'^[0-9a-f]{15,25}$', value, re.IGNORECASE):
        comport = _safe_comport_wrapper(lambda cp: cp.serial_number.upper() == value.upper())
        value = comport.device

    return value


# ---------------- Parse Arguments -------------------
# Defaults
DEFAULT_BAUDRATE = 115200
DEFAULT_BUFFERSIZE = GCodeStreamer.DEFAULT_MAX_BUFFER
DEFAULT_POLL_INTERVAL = 0.2 # seconds
DEFAULT_PENDING_COUNT = 5
DEFAULT_END_SLEEP = 1

parser = argparse.ArgumentParser(
    description="GRBL gcode streamer for CNC machine. Assist jogging to "
                "position, then stream gcode via serial.",
)

parser.add_argument(
    'infile', help="gcode file to stream",
)

parser.add_argument(
    '--quiet', '-q',
    action='store_const', const=True, default=False,
    help="if quiet, help messages won't be printed",
)

# Serial Connection
group = parser.add_argument_group("Serial Connectivity")
group.add_argument(
    '-d', '--device', type=device_type, default=None,
    help="serial device GRBL is connected to, can use direct device name "
         "(eg: /dev/ttyACM0) or the Arduino's serial number (eg: 55639303235351C071B0)"
)
group.add_argument(
    '-b', '--baudrate', type=int, default=DEFAULT_BAUDRATE,
    help="serial baud rate (default: %i)" % DEFAULT_BAUDRATE
)

# Debugging
group = parser.add_argument_group("Debug Parameters")
group.add_argument(
    '--disable-status', dest='status_poll',
    action='store_const', const=False, default=True,
    help="disables '?' being sent every '--poll-interval'",
)
group.add_argument(
    '--poll-interval', dest='poll_interval', type=float, default=DEFAULT_POLL_INTERVAL,
    help="frequency of sending '?' for status report when status is enabled",
)
group.add_argument(
    '--buffer-size', dest='buffer_size', type=int, default=DEFAULT_BUFFERSIZE,
    help="GRBL internal serial buffer size",
)
group.add_argument(
    '--serial-log', dest='serial_log', default=None, metavar="LOG_FILE",
    help="if given, data read from, and written to serial port is logged here "
         "(note: \\r and \\n characters are escaped for debugging purposes)",
)
group.add_argument(
    '--pending-count', dest='pending_count', default=DEFAULT_PENDING_COUNT,
    help="number of gcode lines to display ahead of them being sent",
)
group.add_argument(
    '--keep-open', '-o', dest='no_close',
    action='store_const', const=True, default=False,
    help="if set, window won't close when job is done",
)

args = parser.parse_args()
if args.device is None:
    args.device = device_type(args.device) # FIXME: there has to be a way to do this native to argparse

# ----------------- Curses Shi.. stuff -----------------
def curses_wrap(screen):

    # ----------------- Initialise widgets 'n' stuff -----------------
    # Clear screen
    screen.clear()
    screen.refresh()

    def keypress():
        k = None
        try:
            k = screen.getkey()
        except curses.error as e:
            pass # raised if no key event is buffered
                 # (because that's elegant... hmm)
        return k

    status = Status(screen=screen)
    init = InitWindow(
        screen=screen,
        title='Initialize Device: {}'.format(args.device),
        min_height=1,
    )
    jogging = JoggingWindow(
        screen=screen,
        title='Jogging',
        min_height=1,
    )
    stream = StreamWindow(
        screen=screen,
        title='Stream: {}'.format(args.infile),
        min_height=min(6, args.pending_count + 1),
    )
    accordion = AccordionWindowManager(
        screen=screen,
        windows=[init, jogging, stream],
        header_height=status.window.getmaxyx()[0],
    )

    # dump first few lines into stream window
    with open(args.infile, 'r') as fh:
        for i in range(args.pending_count):
            line = fh.readline().rstrip()
            stream.add_line(line)
        stream.add_line('... [truncated]')


    # ----------------- Virtual Machine -----------------
    machine = NullMachine()

    # Detect & Set Machine's Mode from GRBL text
    machine_mode_regex = re.compile(r'^\s*\[GC:\s*(?P<gcode>[^\]]+)\]\s*$', re.I)
    def machine_set_mode(mode_match):
        machine.set_mode(*text2gcodes(mode_match.group('gcode')))

    # Detect & Set Machine's State from GRBL text
    machine_state_regex = re.compile(r'^\s*<(?P<state>[^\>\<]*)>\s*$')
    def machine_set_state(state_match):
        # <Idle|MPos:0.000,0.000,0.000|FS:0,0|WCO:-8.393,100.000,2.063>
        feed_rate = None # float
        spindle = None  # float
        abs_pos = None  # Position
        work_pos = None  # Position
        work_offset = None  # Position

        coords = lambda s: [float(x) for x in s[s.find(':')+1:].split(',')]
        pos = lambda s: machine.Position(**dict(zip('XYZ', coords(s))))
        for (i, state_str) in enumerate(state_match.group('state').split('|')):
            if i == 0:
                status.set_status(state_str)
            elif state_str.startswith('MPos:'): # machine.abs_pos
                abs_pos = pos(state_str)
            elif state_str.startswith('WPos:'): # machine.pos
                work_pos = pos(state_str)
            elif state_str.startswith('F:'):
                (feed_rate,) = coords(state_str)
            elif state_str.startswith('FS:'):
                (feed_rate, spindle) = coords(state_str)
            elif state_str.startswith('WCO:'): # machine.state.coord_sys.offset
                work_offset = pos(state_str)

        # Update Machine Axes
        if work_offset is not None:
            machine.state.coord_sys.offset = work_offset  # done first
        if abs_pos is not None:
            machine.abs_pos = abs_pos
        if work_pos is not None:
            machine.pos = work_pos

        # Update Status Display
        status.widgets['MPosX'].value = machine.abs_pos.X
        status.widgets['MPosY'].value = machine.abs_pos.Y
        status.widgets['MPosZ'].value = machine.abs_pos.Z
        status.widgets['WPosX'].value = machine.pos.X
        status.widgets['WPosY'].value = machine.pos.Y
        status.widgets['WPosZ'].value = machine.pos.Z
        if feed_rate is not None:
            status.widgets['feed_rate'].text = "%g" % feed_rate
        if spindle is not None:
            spindle_str = ('%g (rpm)' % spindle) if spindle else 'off'
            status.widgets['spindle'].text = spindle_str

        status.refresh()


    # ----------------- Initialize Serial -----------------

    # Initialize & Wake up grbl
    serialport = SerialPort(args.device, args.baudrate, args.serial_log)
    serialport.write("\r\n\r\n")

    # Wait for grbl to initialize and flush startup text in serial input
    accordion.focus = init
    init_complete = False
    for line in serialport.readlines(timeout=5):
        line = line.strip()
        if line and (line != 'ok'):
            init.add_line(line)

        # Process line
        mode_match = machine_mode_regex.search(line)
        state_match = machine_state_regex.search(line)
        if re.search(r'^GRBL', line, re.I):
            # Request: Mode - Request Machine's Mode
            serialport.write('$G\n')
        elif mode_match:
            # Received: Mode - Machine's Mode received, pass to virtual machine
            machine_set_mode(mode_match)
            # Request: State
            serialport.write('?')
        elif state_match:
            # Received: State
            machine_set_state(state_match)
            init_complete = True
        if init_complete:
            break

    if init_complete:
        serialport.serial.flushInput()
    else:
        raise RuntimeError("Could not initialize GRBL serial interface")

    # Machine state initialized, remember it.
    #   machine's mode may be altered while jogging.
    #   machine's mode is duplicated so it may be reverted after jogging
    init_machine = copy.copy(machine)

    # Start period polling of status
    poll_daemon_keepalive = True
    poll_daemon_thread = None
    if args.poll_interval:
        def _poll_daemon_runtime():
            while poll_daemon_keepalive:
              serialport.write('?')
              time.sleep(args.poll_interval)
        poll_daemon_thread = threading.Thread(target=_poll_daemon_runtime)
        poll_daemon_thread.daemon = True
        poll_daemon_thread.start()


    # Serial Polling Process
    message_regex = re.compile(r'^\s*\[(?P<msg>.*)\]\s*$')
    def poll_serial(timeout, callback=None):
        for line in serialport.readlines(timeout=0.05):
            line = line.rstrip('\r\n').lstrip('\r\n')
            state_match = machine_state_regex.search(line)
            message_match = message_regex.search(line)
            #jogging.add_line("%s : %s" % (line, "state" if state_match else "dunno"))
            if state_match: # Received: State
                machine_set_state(state_match)
            elif message_match:
                # TODO: how to display messages
                pass
            else:
                streamer.process_response(line)
                if callback:
                    callback()

    def _poll_callback_jogging():
        jogging.render()
        jogging.refresh()

    def _poll_callback_streaming():
        jogging.render()
        jogging.refresh()
        stream.render()
        stream.refresh()


    # Connect GCode Streamer
    streamer = GCodeStreamer(serialport, args.buffer_size)

    def send_gcode(gcode, window):
        widget = window.add_line(str(gcode))
        line = GCodeStreamer.Line(str(gcode), widget)
        if line: # don't send blank lines
            streamer.send(line)

    # ----------------- Interactive Jogging -----------------
    if not args.quiet:
        help_lines = [
            "; Jogging Keys",
            ";    - Arrow Keys: X/Y axes",
            ";    - PgUp/PgDn: Z axis",
            ";    - []: increase/decrease jog distance",
            ";    - Space: zero work offsets (all axes)",
            ";    - x,y,z: zero individual axis",
            ";    - Enter: start streaming gcode",
        ]
        for line in help_lines:
            jogging.add_line(line)
    accordion.focus = jogging

    screen.nodelay(True) # non-blocking .getkey() behaviour

    while True:
        k = keypress()

        if k is None:
            pass  # nothing pressed; do nothing
        else:
            # Process key-press...
            if k in ('q', 'Q'):
                break
            elif k == '?':
                serialport.write('?')

            # Jogging Keys
            elif k in ["KEY_RIGHT", "KEY_LEFT", "KEY_UP", "KEY_DOWN", "KEY_PPAGE", "KEY_NPAGE"]:
                # put machine into incremental mode (if it's not already)
                if not isinstance(machine.mode.distance, GCodeIncrementalDistanceMode):
                    dist_mode = GCodeIncrementalDistanceMode()
                    send_gcode(dist_mode, jogging)
                    machine.process_gcodes(dist_mode)  # changes machine's mode

                if k == "KEY_RIGHT":
                    send_gcode(GCodeRapidMove(X=status.widgets['jog'].value), jogging)
                    status.widgets['X+'].flash()
                elif k == "KEY_LEFT":
                    send_gcode(GCodeRapidMove(X=-status.widgets['jog'].value), jogging)
                    status.widgets['X-'].flash()
                elif k == "KEY_UP":
                    send_gcode(GCodeRapidMove(Y=status.widgets['jog'].value), jogging)
                    status.widgets['Y+'].flash()
                elif k == "KEY_DOWN":
                    send_gcode(GCodeRapidMove(Y=-status.widgets['jog'].value), jogging)
                    status.widgets['Y-'].flash()
                elif k == "KEY_PPAGE":
                    send_gcode(GCodeRapidMove(Z=status.widgets['jog'].value), jogging)
                    status.widgets['Z+'].flash()
                elif k == "KEY_NPAGE":
                    send_gcode(GCodeRapidMove(Z=-status.widgets['jog'].value), jogging)
                    status.widgets['Z-'].flash()

            # Jogging Increment (up/down)
            elif k in '[],.':
                status.widgets['jog'].value = jog_value(
                    status.widgets['jog'].value,
                    {'[': 1, ',': 1, ']': -1, '.': -1}[k]
                )

            elif k == ' ':
                # Zero WPos coordinates
                send_gcode(text2gcodes('G10 L20 P1 X0 Y0 Z0')[0], jogging)

            elif k == '\n':
                # Jogging complete, begin stream
                break

            elif k == 'KEY_RESIZE':
                # dummy keypress on console window resize
                accordion.update_distrobution()

            status.refresh()

        # spend 50ms processing received serial lines
        #   then loop back up to process another key
        poll_serial(0.05, _poll_callback_jogging)

        streamer.poll_transmission()

    # Revert machine's state after jogging
    mode_keys = set()
    mode_keys |= set(init_machine.mode.modal_groups.keys())
    mode_keys |= set(machine.mode.modal_groups.keys())

    for key in mode_keys:
        initial = init_machine.mode.modal_groups[key]
        current = machine.mode.modal_groups[key]
        if initial != current:
            send_gcode(initial, jogging)


    # ----------------- File Streaming -----------------
    stream.clear()
    accordion.focus = stream

    def _check_resize():
        if keypress() == 'KEY_RESIZE':
            accordion.update_distrobution()


    with open(args.infile, 'r') as gcode_file:
        gcode_file_moredata = True
        while gcode_file_moredata:
            # Push pending lines into streamer
            while streamer.pending_count < args.pending_count:
                line_data = gcode_file.readline()
                if not line_data:
                    gcode_file_moredata = False
                    break # file's done

                send_gcode(line_data.strip(), stream)

            # process serial packets, then try again
            poll_serial(0.05, _poll_callback_streaming)

            _check_resize()

    # streamer is still:
    #   - sending gcodes to GRBL
    #   - processing GRBL's responses in confirmation of those codes
    while not streamer.finished:
        # process serial packets, then try again
        poll_serial(0.05, _poll_callback_streaming)
        _check_resize()

    # Machine is still working, wait 'till it's Idle
    while not status.is_idle:
        # process serial packets, then try again
        poll_serial(0.05, _poll_callback_streaming)
        _check_resize()


    # ---- Kill status polling daemon
    poll_daemon_keepalive = False  # kills polling daemon (if running)
    poll_daemon_thread.join()  # blocks until daemon is complete
    serialport.serial.flushInput()

    while args.no_close:
        if keypress() == 'q':
            break
        time.sleep(0.1)

curses.wrapper(curses_wrap)