viewer.py

#!/usr/bin/env python
# -*- coding: utf8 -*-

__author__ = "Viktor Petersson"
__copyright__ = "Copyright 2012-2013, WireLoad Inc"
__license__ = "Dual License: GPLv2 and Commercial License"

from datetime import datetime, timedelta
from glob import glob
from os import path, getenv, remove, makedirs
from os import stat as os_stat, utime, system, kill
from platform import machine
from random import shuffle
from requests import get as req_get, head as req_head
from stat import S_ISFIFO
from time import sleep, time
import json
import logging
import sh
import signal
from ctypes import cdll

from settings import settings
import html_templates

from utils import url_fails

import db
import assets_helper
# Define to none to ensure we refresh
# the settings.
last_settings_refresh = None
load_screen_pid = None
is_pro_init = None
current_browser_url = None

# Detect the architecture and load the proper video player
arch = machine()
if arch == 'armv6l':
    from sh import omxplayer
elif arch in ['x86_64', 'x86_32']:
    from sh import mplayer

# Used by send_to_front.
libx11 = cdll.LoadLibrary('libX11.so')


def send_to_front(name):
    """Instruct X11 to bring a window with the given name in its title to front."""

    r = [l for l in sh.xwininfo('-root', '-tree').split("\n") if name in l]
    if not len(r) == 1:
        logging.info("Unable to send window with %s in title to front - %d matches found." % (name, len(r)))
        return
    win_id = int(r[0].strip().split(" ", 2)[0], 16)

    dsp = libx11.XOpenDisplay(None)
    logging.debug("Raising %s window %X to front." % (name, win_id))
    libx11.XRaiseWindow(dsp, win_id)
    libx11.XCloseDisplay(dsp)


def get_is_pro_init():
    """
    Function to handle first-run on Screenly Pro
    """
    if path.isfile('/home/pi/.screenly/not_initialized'):
        return False
    else:
        return True


def sigusr1(signum, frame):
    """
    This is the signal handler for SIGUSR1
    The signal interrupts sleep() calls, so
    the currently running asset will be skipped.
    Since video assets don't have a duration field,
    the video player has to be killed.
    """
    logging.info("Signal received, skipping.")
    system("killall omxplayer.bin")


def sigusr2(signum, frame):
    """
    This is the signal handler for SIGUSR2
    Resets the last_settings_refresh timestamp to force
    settings reloading.
    """
    global last_settings_refresh
    logging.info("Signal received, reloading settings.")
    last_settings_refresh = None
    reload_settings()


class Scheduler(object):
    def __init__(self, *args, **kwargs):
        logging.debug('Scheduler init')
        self.update_playlist()

    def get_next_asset(self):
        logging.debug('get_next_asset')
        self.refresh_playlist()
        logging.debug('get_next_asset after refresh')
        if self.nassets == 0:
            return None
        idx = self.index
        self.index = (self.index + 1) % self.nassets
        logging.debug('get_next_asset counter %d returning asset %d of %d' % (self.counter, idx + 1, self.nassets))
        if settings['shuffle_playlist'] and self.index == 0:
            self.counter += 1
        return self.assets[idx]

    def refresh_playlist(self):
        logging.debug('refresh_playlist')
        time_cur = datetime.utcnow()
        logging.debug('refresh: counter: (%d) deadline (%s) timecur (%s)' % (self.counter, self.deadline, time_cur))
        if self.dbisnewer():
            self.update_playlist()
        elif settings['shuffle_playlist'] and self.counter >= 5:
            self.update_playlist()
        elif self.deadline and self.deadline <= time_cur:
            self.update_playlist()

    def update_playlist(self):
        logging.debug('update_playlist')
        (self.assets, self.deadline) = generate_asset_list()
        self.nassets = len(self.assets)
        self.gentime = time()
        self.counter = 0
        self.index = 0
        logging.debug('update_playlist done, count %d, counter %d, index %d, deadline %s' % (self.nassets, self.counter, self.index, self.deadline))

    def dbisnewer(self):
        # get database file last modification time
        try:
            db_mtime = path.getmtime(settings.get_database())
        except:
            db_mtime = 0
        return db_mtime >= self.gentime


def generate_asset_list():
    logging.info('Generating asset-list...')
    playlist = assets_helper.get_playlist(db_conn)
    deadline = sorted([asset['end_date'] for asset in playlist])[0] if len(playlist) > 0 else None
    logging.debug('generate_asset_list deadline: %s' % deadline)

    if settings['shuffle_playlist']:
        shuffle(playlist)

    return (playlist, deadline)


def watchdog():
    """
    Notify the watchdog file to be used with the watchdog-device.
    """

    watchdog = '/tmp/screenly.watchdog'
    if not path.isfile(watchdog):
        open(watchdog, 'w').close()
    else:
        utime(watchdog, None)


def asset_is_accessible(uri):
    """
    Determine if content is accessible or not.
    """

    asset_folder = path.join(getenv('HOME'), 'screenly_assets')
    # If it's local content, just check if the file exist on disk.

    if ((asset_folder in uri) or (html_folder in uri) and path.exists(uri)):
        return True

    try:
        # Give up if we can't even get the header in five seconds.
        remote_asset_status = req_head(uri, timeout=5, allow_redirects=True).status_code
        if remote_asset_status == 200:
            return True
        else:
            return False
    except:
        return False


def load_browser():
    logging.info('Loading browser...')

    global is_pro_init, current_browser_url
    is_pro_init = get_is_pro_init()
    if not is_pro_init:
        logging.debug('Detected Pro initiation cycle.')

        # Wait for the intro file to exist (if it doesn't)
        intro_file = '/home/pi/.screenly/intro.html'
        while not path.isfile(intro_file):
            logging.debug('intro.html missing. Going to sleep.')
            sleep(0.5)

        browser_load_url = 'file://' + intro_file

    elif settings['show_splash']:
        browser_load_url = "http://%s:%s/splash_page" % (settings.get_listen_ip(), settings.get_listen_port())
    else:
        browser_load_url = black_page

    browser = sh.Command('uzbl-browser')(uri=browser_load_url, _bg=True)
    current_browser_url = browser_load_url

    logging.info('Browser loaded. Running as PID %d.' % browser.pid)

    if settings['show_splash']:
        # Show splash screen for 60 seconds.
        sleep(60)
    else:
        # Give browser some time to start (we have seen multiple uzbl running without this)
        sleep(10)

    return browser


def get_fifo():
    """
    Look for UZBL's FIFO-file in /tmp.
    Don't give up until it has been found.
    """
    found_fifo = False
    fifo = None

    logging.debug('Looking for UZBL fifo...')

    while not found_fifo:
        candidates = glob('/tmp/uzbl_fifo_*')
        for file in candidates:
            if S_ISFIFO(os_stat(file).st_mode):
                found_fifo = True
                fifo = file
        sleep(0.5)
    logging.debug('Found UZBL fifo  in %s.' % file)
    return fifo


def browser_fifo(data):
    f = open(fifo, 'a')
    f.write('%s\n' % data)
    f.close()


def browser_socket(command, timeout=0.5):
    """Like browser_fifo but also read back any immediate response from UZBL.

    Note that the response can be anything, including events entirely unrelated
    to the command executed.
    """

    uzbl_socket = "/tmp/uzbl_socket_%d" % browser_pid
    r = sh.socat("-t%f" % timeout, "-", "unix-connect:%s" % uzbl_socket, _in=command + "\n")
    # Very spammy.
    # logging.debug("browser_socket(%r) -> %r" % (command, r))
    return r


def browser_page_has(name):
    """Return true if the given name is defined on the currently loaded browser page."""

    positive_response = "COMMAND_EXECUTED js  'typeof(%s) !== \\'undefined\\''\ntrue" % name
    return positive_response in browser_socket("js typeof(%s) !== 'undefined'" % name)


def browser_reload(force=False):
    """
    Reload the browser. Use to Force=True to force-reload
    """

    if not force:
        reload_command = 'reload'
    else:
        reload_command = 'reload_ign_cache'

    browser_fifo(reload_command)


def browser_clear():
    """Clear the browser if necessary.

    Call this function right before displaying now browser content (with feh or omx).

    When a web assset is loaded into the browser, it's not cleared after the duration but instead
    remains displayed until the next asset is ready to show. This minimises the amount of transition
    time - in the case where the next asset is also web content the browser is never cleared,
    and in other cases it's cleared as late as possible.

    """

    if current_browser_url != black_page:
        browser_url(black_page)


def browser_url(url):
    global current_browser_url

    if url == current_browser_url:
        logging.debug("Already showing %s, keeping it." % url)
        return
    browser_fifo('set uri = %s' % url)
    current_browser_url = url


def disable_browser_status():
    logging.debug('Disabled status-bar in browser')
    browser_fifo('set show_status = 0')


def view_image(uri, duration):
    logging.debug('Displaying image %s for %s seconds.' % (uri, duration))

    if asset_is_accessible(uri):
        run = sh.feh(uri, scale_down=True, borderless=True, fullscreen=True, cycle_once=True, slideshow_delay=duration, _bt=True)
        # Wait until feh is starting before clearing the browser. This minimises delay between
        # web and image content.
        browser_clear()
        run.wait()
    else:
        logging.debug('Received non-200 status (or file not found if local) from %s. Skipping.' % (uri))


def view_video(uri):

    ## For Raspberry Pi
    if arch == 'armv6l':
        logging.debug('Displaying video %s. Detected Raspberry Pi. Using omxplayer.' % uri)

        if asset_is_accessible(uri):
            run = omxplayer(uri, o=settings['audio_output'], _bg=True)
        else:
            logging.debug('Content is unaccessible. Skipping...')
            return

        # Wait until omxplayer is starting before clearing the browser. This minimises delay between
        # web and image content. Omxplayer will run on top of the browser so the delay in clearing
        # won't be visible. This minimises delay between web and video.
        browser_clear()
        run.wait()

        if run.exit_code != 0:
            logging.debug("Unclean exit: " + str(run))

        # Clean up after omxplayer
        omxplayer_logfile = path.join(getenv('HOME'), 'omxplayer.log')
        if path.isfile(omxplayer_logfile):
            remove(omxplayer_logfile)

    ## For x86
    elif arch in ['x86_64', 'x86_32']:
        logging.debug('Displaying video %s. Detected x86. Using mplayer.' % uri)

        if asset_is_accessible(uri):
            run = mplayer(uri, fs=True, nosound=True, _bg=True)
        else:
            logging.debug('Content is unaccessible. Skipping...')
            return

        browser_clear()
        run.wait()

        if run.exit_code != 0:
            logging.debug("Unclean exit: " + str(run))


def view_web(url, duration):
    if asset_is_accessible(url):
        logging.debug('Web content appears to be available. Proceeding.')
        logging.debug('Displaying url %s for %s seconds.' % (url, duration))

        browser_url(url)

        sleep(int(duration))
    else:
        logging.debug('Received non-200 status (or file not found if local) from %s. Skipping.' % (url))


def toggle_load_screen(status=True):
    """
    Toggle the load screen. Set status to either True or False.
    """

    load_screen = '/home/pi/screenly/loading.jpg'
    global load_screen_pid

    if status and path.isfile(load_screen):
        if not load_screen_pid:
            image_loader = sh.feh(load_screen, scale_down=True, borderless=True, fullscreen=True, _bg=True)
            load_screen_pid = image_loader.pid
            logging.debug("Load screen PID: %d." % load_screen_pid)
        else:
            # If we're already showing the load screen, just make sure it's on top.
            send_to_front("feh")
    elif not status and load_screen_pid:
        logging.debug("Killing load screen with PID: %d." % load_screen_pid)
        kill(load_screen_pid, signal.SIGTERM)
        load_screen_pid = None

    return load_screen_pid


def check_update():
    """
    Check if there is a later version of Screenly-OSE
    available. Only do this update once per day.

    Return True if up to date was written to disk,
    False if no update needed and None if unable to check.
    """

    sha_file = path.join(getenv('HOME'), '.screenly', 'latest_screenly_sha')

    if path.isfile(sha_file):
        sha_file_mtime = path.getmtime(sha_file)
        last_update = datetime.fromtimestamp(sha_file_mtime)
    else:
        last_update = None

    logging.debug('Last update: %s' % str(last_update))

    if last_update is None or last_update < (datetime.now() - timedelta(days=1)):

        if asset_is_accessible('http://stats.screenlyapp.com'):
            latest_sha = req_get('http://stats.screenlyapp.com/latest')

            if latest_sha.status_code == 200:
                with open(sha_file, 'w') as f:
                    f.write(latest_sha.content.strip())
                return True
            else:
                logging.debug('Received on 200-status')
                return
        else:
            logging.debug('Unable to retreive latest SHA')
            return
    else:
        return False


def reload_settings():
    """
    Reload settings if the timestamp of the
    settings file is newer than the settings
    file loaded in memory.
    """

    settings_file = path.join(getenv('HOME'), '.screenly', 'screenly.conf')
    settings_file_mtime = path.getmtime(settings_file)
    settings_file_timestamp = datetime.fromtimestamp(settings_file_mtime)

    if not last_settings_refresh or settings_file_timestamp > last_settings_refresh:
        settings.load()

    logging.getLogger().setLevel(logging.DEBUG if settings['debug_logging'] else logging.INFO)

    global last_setting_refresh
    last_setting_refresh = datetime.utcnow()


if __name__ == "__main__":

    # Bring up load screen
    toggle_load_screen(True)

    # Install signal handlers
    signal.signal(signal.SIGUSR1, sigusr1)
    signal.signal(signal.SIGUSR2, sigusr2)

    # Before we start, reload the settings.
    reload_settings()

    global db_conn
    db_conn = db.conn(settings.get_database())

    # Create folder to hold HTML-pages
    html_folder = '/tmp/screenly_html/'
    if not path.isdir(html_folder):
        makedirs(html_folder)

    # Set up HTML templates
    black_page = html_templates.black_page()

    # Fire up the browser
    run_browser = load_browser()

    logging.debug('Getting browser PID.')
    browser_pid = run_browser.pid

    logging.debug('Getting FIFO.')
    fifo = get_fifo()

    logging.debug('Disable the browser status bar.')
    disable_browser_status()

    # Disable load screen early if initialization mode
    if not is_pro_init:
        toggle_load_screen(False)

    # Wait until initialized (Pro only).
    did_show_pin = False
    did_show_claimed = False
    while not get_is_pro_init():
        # Wait for the status page to fully load.
        while not browser_page_has("showPin"):
            logging.debug("Waiting for intro page to load...")
            sleep(1)

        with open('/home/pi/.screenly/setup_status.json', 'rb') as status_file:
            status = json.load(status_file)

        if not did_show_pin and not did_show_claimed and status.get('pin'):
            browser_fifo('''js showPin("%s")''' % status.get('pin').replace('"', '\\"'))
            did_show_pin = True

        if not did_show_claimed and status.get('claimed'):
            browser_fifo('''js showUpdating()''')
            did_show_claimed = True

        logging.debug('Waiting for node to be initialized.')
        sleep(1)

    # Bring up the blank page (in case there are only videos).
    logging.debug('Loading blank page.')
    view_web(black_page, 1)

    scheduler = Scheduler()

    # Infinite loop.
    logging.debug('Entering infinite loop.')
    while True:
        asset = scheduler.get_next_asset()
        logging.debug('got asset %s' % asset)

        is_up_to_date = check_update()
        logging.debug('Check update: %s' % str(is_up_to_date))

        if asset is None:
            # The playlist is empty, go to sleep.
            logging.info('Playlist is empty. Going to sleep.')
            toggle_load_screen(True)
            browser_clear()
            sleep(5)
        elif not url_fails(asset['uri']):
            toggle_load_screen(False)
            logging.info('Showing asset %s.' % asset["name"])

            watchdog()

            if "image" in asset["mimetype"]:
                view_image(asset['uri'], asset["duration"])
            elif "video" in asset["mimetype"]:
                view_video(asset["uri"])
            elif "web" in asset["mimetype"]:
                view_web(asset["uri"], asset["duration"])
            else:
                print "Unknown MimeType, or MimeType missing"
        else:
            logging.info('Asset {0} is not available, skipping.'.format(asset['uri']))