subiquity/subiquitycore/core.py

# Copyright 2015 Canonical, Ltd.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from concurrent import futures
import fcntl
import logging
import sys

import urwid
import yaml

from subiquitycore.signals import Signal
from subiquitycore.prober import Prober, ProberException

log = logging.getLogger('subiquitycore.core')


class ApplicationError(Exception):
    """ Basecontroller exception """
    pass

# The next little bit is cribbed from
# https://github.com/EvanPurkhiser/linux-vt-setcolors/blob/master/setcolors.c:

# From uapi/linux/kd.h:
KDGKBTYPE = 0x4B33  # get keyboard type
GIO_CMAP  = 0x4B70	# gets colour palette on VGA+
PIO_CMAP  = 0x4B71	# sets colour palette on VGA+
UO_R, UO_G, UO_B = 0xe9, 0x54, 0x20


class ISO_8613_3_Screen(urwid.raw_display.Screen):

    def __init__(self, _urwid_name_to_rgb):
        self._fg_to_rgb = _urwid_name_to_rgb.copy()
        self._fg_to_rgb['default'] = _urwid_name_to_rgb['light gray']
        self._bg_to_rgb = _urwid_name_to_rgb.copy()
        self._bg_to_rgb['default'] = _urwid_name_to_rgb['black']
        super().__init__()

    def _attrspec_to_escape(self, a):
        f_r, f_g, f_b = self._fg_to_rgb[a.foreground]
        b_r, b_g, b_b = self._bg_to_rgb[a.background]
        return "\x1b[38;2;{};{};{};48;2;{};{};{}m".format(f_r, f_g, f_b, b_r, b_g, b_b)


def is_linux_tty():
    try:
        r = fcntl.ioctl(sys.stdout.fileno(), KDGKBTYPE, ' ')
    except IOError as e:
        log.debug("KDGKBTYPE failed %r", e)
        return False
    log.debug("KDGKBTYPE returned %r", r)
    return r == b'\x02'



def setup_screen(colors, styles):
    """Return a palette and screen to be passed to MainLoop.

    colors is a list of exactly 8 tuples (name, (r, g, b))

    styles is a list of tuples (stylename, fg_color, bg_color) where
    fg_color and bg_color are defined in 'colors'
    """
    # The part that makes this "fun" is that urwid insists on referring
    # to the basic colors by their "standard" names but we overwrite
    # these colors to mean different things.  So we convert styles into
    # an urwid palette by mapping the names in colors to the standard
    # name, and then either overwrite the first 8 colors to be the
    # colors from 'colors' (on the linux vt) or use a custom screen
    # class that displays maps the standard color name to the value
    # specified in colors using 24-bit control codes.
    if len(colors) != 8:
        raise Exception("setup_screen must be passed a list of exactly 8 colors")
    urwid_8_names = (
        'black',
        'dark red',
        'dark green',
        'brown',
        'dark blue',
        'dark magenta',
        'dark cyan',
        'light gray',
    )
    urwid_name = dict(zip([c[0] for c in colors], urwid_8_names))

    urwid_palette = []
    for name, fg, bg in styles:
        urwid_palette.append((name, urwid_name[fg], urwid_name[bg]))

    if is_linux_tty():
        curpal = bytearray(16*3)
        fcntl.ioctl(sys.stdout.fileno(), GIO_CMAP, curpal)
        for i in range(8):
            for j in range(3):
                curpal[i*3+j] = colors[i][1][j]
        fcntl.ioctl(sys.stdout.fileno(), PIO_CMAP, curpal)
        return urwid.raw_display.Screen(), urwid_palette
    else:
        _urwid_name_to_rgb = {}
        for i, n in enumerate(urwid_8_names):
            _urwid_name_to_rgb[n] = colors[i][1]
        return ISO_8613_3_Screen(_urwid_name_to_rgb), urwid_palette


class Application:

    # A concrete subclass must set project and controllers attributes, e.g.:
    #
    # project = "subiquity"
    # controllers = [
    #         "Welcome",
    #         "Installpath",
    #         "Network",
    #         "Filesystem",
    #         "Identity",
    #         "InstallProgress",
    #         "Login",
    # ]
    # The 'next-screen' and 'prev-screen' signals move through the list of
    # controllers in order, calling the default method on the controller
    # instance.

    def __init__(self, ui, opts):
        try:
            prober = Prober(opts)
        except ProberException as e:
            err = "Prober init failed: {}".format(e)
            log.exception(err)
            raise ApplicationError(err)

        opts.project = self.project

        answers = {}
        if opts.answers is not None:
            answers = yaml.safe_load(open(opts.answers).read())
            log.debug("Loaded answers %s", answers)
            if not opts.dry_run:
                open('/run/casper-no-prompt', 'w').close()

        self.common = {
            "ui": ui,
            "opts": opts,
            "signal": Signal(),
            "prober": prober,
            "loop": None,
            "pool": futures.ThreadPoolExecutor(1),
            "answers": answers,
        }
        if opts.screens:
            self.controllers = [c for c in self.controllers if c in opts.screens]
        ui.progress_completion = len(self.controllers)
        self.common['controllers'] = dict.fromkeys(self.controllers)
        self.controller_index = -1

    def _connect_base_signals(self):
        """ Connect signals used in the core controller
        """
        signals = []

        signals.append(('quit', self.exit))
        if self.common['opts'].dry_run:
            signals.append(('control-x-quit', self.exit))
        signals.append(('refresh', self.redraw_screen))
        signals.append(('next-screen', self.next_screen))
        signals.append(('prev-screen', self.prev_screen))
        self.common['signal'].connect_signals(signals)

        # Registers signals from each controller
        for controller, controller_class in self.common['controllers'].items():
            controller_class.register_signals()
        log.debug(self.common['signal'])

    def next_screen(self, *args):
        self.controller_index += 1
        if self.controller_index >= len(self.controllers):
            self.exit()
        self.common['ui'].progress_current += 1
        controller_name = self.controllers[self.controller_index]
        log.debug("moving to screen %s", controller_name)
        next_controller = self.common['controllers'][controller_name]
        next_controller.default()

    def prev_screen(self, *args):
        if self.controller_index == 0:
            return
        self.controller_index -= 1
        if self.controller_index >= len(self.controllers):
            self.exit()
        self.common['ui'].progress_current -= 1
        controller_name = self.controllers[self.controller_index]
        next_controller = self.common['controllers'][controller_name]
        next_controller.default()

# EventLoop -------------------------------------------------------------------
    def redraw_screen(self):
        if self.common['loop'] is not None:
            try:
                self.common['loop'].draw_screen()
            except AssertionError as e:
                log.critical("Redraw screen error: {}".format(e))

    def exit(self):
        raise urwid.ExitMainLoop()

    def run(self):
        if not hasattr(self, 'loop'):
            if self.common['opts'].run_on_serial:
                palette = self.STYLES_MONO
                screen = urwid.raw_display.Screen()
            else:
                screen, palette = setup_screen(self.COLORS, self.STYLES)

            self.common['loop'] = urwid.MainLoop(
                self.common['ui'], palette=palette, screen=screen,
                handle_mouse=False, pop_ups=True)
            log.debug("Running event loop: {}".format(
                self.common['loop'].event_loop))

            self.common['base_model'] = self.model_class(self.common)

        try:
            self.common['loop'].set_alarm_in(0.05, self.next_screen)
            controllers_mod = __import__('%s.controllers' % self.project, None, None, [''])
            for k in self.controllers:
                log.debug("Importing controller: {}".format(k))
                klass = getattr(controllers_mod, k+"Controller")
                self.common['controllers'][k] = klass(self.common)
            log.debug("*** %s", self.common['controllers'])
            self._connect_base_signals()
            self.common['loop'].run()
        except:
            log.exception("Exception in controller.run():")
            raise