Anthias/lib/utils.py

import certifi
import db
import json
import os
import pytz
import random
import re
import requests
import string

from datetime import datetime, timedelta
from distutils.util import strtobool
from netifaces import ifaddresses, gateways, AF_INET
from os import getenv, path, utime
from platform import machine
from settings import settings, ZmqPublisher
from sh import grep, netstat, ErrorReturnCode_1
from subprocess import check_output, call
from threading import Thread
from urlparse import urlparse

from assets_helper import update

arch = machine()

# 300 level HTTP responses are also ok, such as redirects, which many sites have and load
HTTP_OK = xrange(200, 399)

# This will only work on the Raspberry Pi,
# so let's wrap it in a try/except so that
# Travis can run.
try:
    from sh import omxplayer
except ImportError:
    pass

# This will work on x86-based machines
if machine() in ['x86', 'x86_64']:
    try:
        from sh import ffprobe, mplayer
    except ImportError:
        pass


def string_to_bool(string):
    return bool(strtobool(str(string)))


def touch(path):
    with open(path, 'a'):
        utime(path, None)


def is_ci():
    """
    Returns True when run on Travis.
    """
    return string_to_bool(os.getenv('CI', False))


def validate_url(string):
    """Simple URL verification.
    >>> validate_url("hello")
    False
    >>> validate_url("ftp://example.com")
    False
    >>> validate_url("http://")
    False
    >>> validate_url("http://wireload.net/logo.png")
    True
    >>> validate_url("https://wireload.net/logo.png")
    True
    """

    checker = urlparse(string)
    return bool(checker.scheme in ('http', 'https', 'rtsp', 'rtmp') and checker.netloc)


def get_node_ip():
        """Returns the node's IP, for the interface
        that is being used as the default gateway.
        This should work on both MacOS X and Linux."""
        try:
            default_interface = gateways()['default'][AF_INET][1]
            my_ip = ifaddresses(default_interface)[AF_INET][0]['addr']
            return my_ip
        except ValueError:
            raise Exception("Unable to resolve local IP address.")


def get_video_duration(file):
    """
    Returns the duration of a video file in timedelta.
    """
    time = None

    try:
        if arch in ('armv6l', 'armv7l'):
            run_player = omxplayer(file, info=True, _err_to_out=True, _ok_code=[0, 1], _decode_errors='ignore')
        else:
            run_player = ffprobe('-i', file, _err_to_out=True)
    except ErrorReturnCode_1:
        raise Exception('Bad video format')

    for line in run_player.split('\n'):
        if 'Duration' in line:
            match = re.search(r'[0-9]+:[0-9]+:[0-9]+\.[0-9]+', line)
            if match:
                time_input = match.group()
                time_split = time_input.split(':')
                hours = int(time_split[0])
                minutes = int(time_split[1])
                seconds = float(time_split[2])
                time = timedelta(hours=hours, minutes=minutes, seconds=seconds)
            break

    return time


def handler(obj):
    # Set timezone as UTC if it's datetime and format as ISO
    if isinstance(obj, datetime):
        with_tz = obj.replace(tzinfo=pytz.utc)
        return with_tz.isoformat()
    else:
        raise TypeError('Object of type %s with value of %s is not JSON serializable' % (type(obj), repr(obj)))


def json_dump(obj):
    return json.dumps(obj, default=handler)


def url_fails(url):
    """
    If it is streaming
    """
    if urlparse(url).scheme in ('rtsp', 'rtmp'):
        if arch in ('armv6l', 'armv7l'):
            run_omxplayer = omxplayer(url, info=True, _err_to_out=True, _ok_code=[0, 1])
            for line in run_omxplayer.split('\n'):
                if 'Input #0' in line:
                    return False
            return True
        else:
            run_mplayer = mplayer('-identify', '-frames', '0', '-nosound', url)
            for line in run_mplayer.split('\n'):
                if 'Clip info:' in line:
                    return False
            return True

    """
    Try HEAD and GET for URL availability check.
    """

    # Use Certifi module and set to True as default so users stop seeing InsecureRequestWarning in logs
    if settings['verify_ssl']:
        verify = certifi.where()
    else:
        verify = True

    headers = {
        'User-Agent': 'Mozilla/5.0 (X11; Linux armv7l) AppleWebKit/538.15 (KHTML, like Gecko) Version/8.0 Safari/538.15'
    }
    try:
        if not validate_url(url):
            return False

        if requests.head(
            url,
            allow_redirects=True,
            headers=headers,
            timeout=10,
            verify=verify
        ).status_code in HTTP_OK:
            return False

        if requests.get(
            url,
            allow_redirects=True,
            headers=headers,
            timeout=10,
            verify=verify
        ).status_code in HTTP_OK:
            return False

    except (requests.ConnectionError, requests.exceptions.Timeout):
        pass

    return True


def download_video_from_youtube(uri, asset_id):
    home = getenv('HOME')
    name = check_output(['youtube-dl', '-e', uri])
    info = json.loads(check_output(['youtube-dl', '-j', uri]))
    duration = info['duration']

    location = path.join(home, 'screenly_assets', asset_id)
    thread = YoutubeDownloadThread(location, uri, asset_id)
    thread.daemon = True
    thread.start()

    return location, unicode(name.decode('utf-8')), duration


class YoutubeDownloadThread(Thread):
    def __init__(self, location, uri, asset_id):
        Thread.__init__(self)
        self.location = location
        self.uri = uri
        self.asset_id = asset_id

    def run(self):
        publisher = ZmqPublisher.get_instance()
        call(['youtube-dl', '-f', 'mp4', '-o', self.location, self.uri])
        with db.conn(settings['database']) as conn:
            update(conn, self.asset_id, {'asset_id': self.asset_id, 'is_processing': 0})

        publisher.send_to_ws_server(self.asset_id)


def template_handle_unicode(value):
    if isinstance(value, str):
        return value.decode('utf-8')
    return unicode(value)


def is_demo_node():
    """
    Check if the environment variable IS_DEMO_NODE is set to 1
    :return: bool
    """
    return string_to_bool(os.getenv('IS_DEMO_NODE', False))


def generate_perfect_paper_password(pw_length=10, has_symbols=True):
    """
    Generates a password using 64 characters from
    "Perfect Paper Password" system by Steve Gibson

    :param pw_length: int
    :param has_symbols: bool
    :return: string
    """
    ppp_letters = '!#%+23456789:=?@ABCDEFGHJKLMNPRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
    if not has_symbols:
        ppp_letters = ''.join(set(ppp_letters) - set(string.punctuation))
    return "".join(random.SystemRandom().choice(ppp_letters) for _ in range(pw_length))