app/common/common.py

   1 import os
   2 import re
   3 import json
   4 import base64
   5 import sqlite3
   6 import requests
   7 import hmac, hashlib
   8 import requests_cache
   9 import dateutil.parser
  10 from xml.etree import ElementTree
  11 from configparser import ConfigParser
  12 from datetime import datetime, timezone
  13 from urllib.parse import parse_qs, urlparse
  14
  15 cf = ConfigParser()
  16 config_filename = os.environ.get('YT_CONFIG', '/etc/yt/config.ini')
  17 cf.read(config_filename)
  18 if not 'global' in cf: # todo: full config check
  19     raise Exception("Configuration file not found or empty")
  20
  21 # Note: currently expiring after 10 minutes. googlevideo-urls are valid for 5h59m, but this makes reddit very stale and premiere videos won't start.  TODO: exipre when video is livestream/premiere/etc
  22 requests_cache.install_cache(backend='memory', expire_after=10*60, allowable_codes=(200,), allowable_methods=('GET', 'HEAD', 'POST'))
  23
  24 # Note: requests-cache doesn't use redis expiry, so we need this in all backends:
  25 # https://github.com/reclosedev/requests-cache/issues/58#issuecomment-164537971
  26 # TODO: only run for long-running processes, i.e. the frontend
  27 from threading import Timer
  28 def purge_cache(sec):
  29     requests_cache.remove_expired_responses()
  30     t = Timer(sec, purge_cache, args=(sec,))
  31     t.setDaemon(True)
  32     t.start()
  33 purge_cache(10*60)
  34
  35 # for debugging purposes, monkey patch requests session to store each requests-request in a flask-request's g object (url and response). we can then use a flask error_handler to include the request data in the error log.
  36 # since we also call config from outside the flask appcontext, it is wrapped in a try-catch block.
  37 from flask import g
  38 import requests
  39 from requests import Session as OriginalSession
  40 class _NSASession(OriginalSession):
  41     def request(self, method, url, params=None, data=None, **kwargs):
  42         response = super(_NSASession, self).request(
  43             method, url, params, data, **kwargs
  44             )
  45         try:
  46             if 'api_requests' not in g:
  47                 g.api_requests = []
  48             g.api_requests.append((url, params, response.text))
  49         except RuntimeError: pass # not within flask (e.g. utils.py)
  50         return response
  51 requests.Session = requests.sessions.Session = _NSASession
  52
  53 def fetch_xml(feed_type, feed_id):
  54     # TODO: handle requests.exceptions.ConnectionError
  55     r = requests.get("https://www.youtube.com/feeds/videos.xml", {
  56         feed_type: feed_id,
  57     })
  58     if not r.ok:
  59         return None
  60
  61     return r.content
  62
  63 def parse_xml(xmldata):
  64     ns = {
  65         'atom':"http://www.w3.org/2005/Atom",
  66         'yt': "http://www.youtube.com/xml/schemas/2015",
  67         'media':"http://search.yahoo.com/mrss/",
  68         'at': "http://purl.org/atompub/tombstones/1.0",
  69     }
  70
  71     feed = ElementTree.fromstring(xmldata)
  72
  73     if feed.find('at:deleted-entry',ns):
  74         (_,_,vid) = feed.find('at:deleted-entry',ns).get('ref').rpartition(':')
  75         return None, None, [{'deleted': True, 'video_id': vid}], None, None
  76
  77     title = feed.find('atom:title',ns).text
  78     author = feed.find('atom:author/atom:name',ns).text \
  79         if feed.find('atom:author',ns) else None
  80     # for /user/<> endpoint: find out UC-id:
  81     # for playlists: this is who created the playlist:
  82     try:   channel_id = feed.find('yt:channelId',ns).text
  83     except:channel_id=None # XXX: why does ternary not work!?
  84     # for pullsub: if this exists, we're looking at a playlist:
  85     try:   playlist_id = feed.find('yt:playlistId',ns).text
  86     except:playlist_id=None # XXX: why does ternary not work!?
  87     videos = []
  88     for entry in feed.findall('atom:entry',ns):
  89         videos.append({
  90             'video_id': entry.find('yt:videoId',ns).text,
  91             'title': entry.find('atom:title',ns).text,
  92             'published': entry.find('atom:published',ns).text,
  93             'channel_id': entry.find('yt:channelId',ns).text,
  94             'author': entry.find('atom:author',ns).find('atom:name',ns).text,
  95             # extra fields for pull_subs/webhook:
  96             'updated': entry.find('atom:updated',ns).text,
  97         })
  98
  99     return title, author, videos, channel_id, playlist_id
 100
 101 def update_channel(db, xmldata, from_webhook=False):
 102     if not xmldata: return False
 103
 104     # Note: websub does not return global author, hence taking from first video
 105     title, author, videos, channel, playlist = parse_xml(xmldata)
 106
 107     c = db.cursor()
 108     for i, video in enumerate(videos):
 109         if video.get('deleted'):
 110             # Note: Deletion events are not just fired for actual deletions,
 111             # but also for unlisting videos and livestreams that just ended
 112             # (even postLiveDVR ones). Hence, we don't follow it.
 113             flask_logger(f"ignoring deleted/unlisted/ended video/stream {video['video_id']}")
 114             break
 115
 116         c.execute("SELECT 1 FROM videos WHERE id=?",(video['video_id'],))
 117         new_video = len(c.fetchall()) < 1
 118         if new_video:
 119             # TODO: call store_video_metadata(video_id) here instead and pass video-fallback-metadata to it
 120             _, _, meta, _, _ = get_video_info(video['video_id'], metaOnly=True)
 121             # The 'published' timestamp sent in websub POSTs are often wrong (e.g.:
 122             # video gets uploaded as unlisted on day A and set to public on day B;
 123             # the webhook is sent on day B, but 'published' says A. The video
 124             # therefore looks like it's just an update to an older video).
 125             # g_v_i gives is the date the video was published to viewers, so we
 126             # prefer that. But since g_v_i only returns the date without time,
 127             # we still use xmlfeed's date if it's the same date.
 128             published = dateutil.parser.parse(video['published'])
 129             length = None
 130             livestream = None
 131             premiere = None
 132             if meta:
 133                 meta = video_metadata(meta)
 134                 published2 = dateutil.parser.parse(meta['published'])
 135                 if published < published2: # g_v_i date is more accurate:
 136                     published = published2
 137                 length = meta['length']
 138                 livestream = meta['livestream']
 139                 premiere = meta['premiere']
 140
 141             now = datetime.now(timezone.utc)
 142
 143             # we pretend that all videos uploaded this week were uploaded just
 144             # now, so the user sees it at the top of the feed, and it doesn't
 145             # get inserted somewhere further down.
 146             if (now - published).days < 7:
 147                 timestamp = now
 148             else:#, it's just an update to an older video.
 149                 timestamp = published
 150
 151             c.execute("""
 152                 INSERT OR IGNORE INTO videos
 153                     (id, channel_id, title, length, livestream, premiere, published, crawled)
 154                 VALUES (?, ?, ?, ?, ?, ?, datetime(?), datetime(?))
 155             """, (
 156                 video['video_id'],
 157                 video['channel_id'],
 158                 video['title'],
 159                 length,
 160                 livestream,
 161                 premiere,
 162                 published,
 163                 timestamp
 164             ))
 165         else:
 166             # update video title (everything else can't change)
 167             c.execute("""
 168                 UPDATE OR IGNORE videos
 169                     SET title = ?
 170                     WHERE id = ?
 171             """, (
 172                 video['title'],
 173                 video['video_id'],
 174             ))
 175
 176         # for channels, this is obviously always the same, but playlists can
 177         # consist of videos from different channels:
 178         if i == 0 or playlist:
 179             c.execute("""
 180                 INSERT OR REPLACE INTO channels (id, name)
 181                                 VALUES (?, ?)
 182             """, (video['channel_id'], video['author']))
 183
 184         # keep track of which videos are in a playlist, so we can show the user
 185         # why a video is in their feed:
 186         if playlist:
 187             c.execute("""
 188                 INSERT OR IGNORE INTO playlist_videos (video_id, playlist_id)
 189                                VALUES (?, ?)
 190             """, (video['video_id'], playlist))
 191
 192     if playlist and not from_webhook: # Note: playlists can't get updated via websub
 193         c.execute("""
 194             INSERT OR REPLACE INTO playlists (id, name, author)
 195                             VALUES (?, ?, ?)
 196             """, (playlist, title, channel))
 197         c.execute("""
 198             INSERT OR REPLACE INTO channels (id, name)
 199                             VALUES (?, ?)
 200         """, (channel, author))
 201
 202     db.commit()
 203
 204     return True
 205
 206 def get_video_info(video_id, *, metaOnly=False, _embed=True):
 207     """
 208     returns: best-quality muxed video stream, stream map, player_response, error-type/mesage
 209     error types: player, malformed, livestream, geolocked, agegated, no-url, exhausted
 210     """
 211     player_error, metadata = None, None # for 'exhausted'
 212     with sqlite3.connect(cf['global']['database']) as conn:
 213         c = conn.cursor()
 214         c.execute("SELECT * FROM captcha_cookies")
 215         cookies = dict(c.fetchall())
 216     today = datetime.now(timezone.utc).strftime("%Y%m%d")
 217     # XXX: anticaptcha hasn't been adapted
 218     # XXX: this is not cached any more!
 219     key = "AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8"
 220     r = requests.post("https://www.youtube-nocookie.com/youtubei/v1/player", params={'key': key}, json={
 221         'videoId': video_id,
 222         'context': {
 223             'client': {
 224                 'gl': 'US',
 225                 'hl': 'en',
 226                 # ANDROID returns streams that are not throttled or cipher-scambled, but less metadata than WEB
 227                 'clientName': 'ANDROID' if not metaOnly else 'WEB',
 228                 'clientVersion': f'16.20' if not metaOnly else f'2.{today}.01.01',
 229                 **({'clientScreen': 'EMBED'} if _embed else {}),
 230             },
 231             'thirdParty': {'embedUrl': 'https://google.com'}
 232         },
 233     }, cookies=cookies)
 234
 235     if not r or r.status_code == 429:
 236         return None, None, None, 'banned', 'possible IP ban'
 237
 238     metadata = r.json()
 239     if "error" in metadata:
 240         return None, None, metadata, "malformed", metadata.get("error",{}).get("message","")
 241     playabilityStatus = metadata['playabilityStatus']['status']
 242     if playabilityStatus != "OK":
 243         playabilityReason = metadata['playabilityStatus'].get('reason',
 244                 '//'.join(metadata['playabilityStatus'].get('messages',[])))
 245         player_error = f"{playabilityStatus}: {playabilityReason}"
 246         # "Watch on YouTube" button is visible => "Playback on other websites
 247         # has been disabled by the video owner." => retry detailpage API
 248         if (playabilityStatus == "UNPLAYABLE" and
 249             'proceedButton' in metadata['playabilityStatus'] \
 250                 .get('errorScreen',{}).get('playerErrorMessageRenderer',{})
 251             and not metaOnly # only need metadata (e.g. called from pubsubhubbub)
 252             and _embed
 253
 254         ):
 255             _, _, metadata_embed, error_embed, errormsg_embed = get_video_info(video_id, _embed=False)
 256             if not error_embed or error_embed in ('livestream','geolocked'):
 257                 metadata = metadata_embed
 258             elif errormsg_embed == "LOGIN_REQUIRED: Sign in to confirm your age":
 259                 return None, None, metadata, 'agegated', player_error
 260             else:
 261                 return None, None, metadata, error_embed, errormsg_embed
 262         else:
 263             # without videoDetails, there's only the error message
 264             maybe_metadata = metadata if 'videoDetails' in metadata else None
 265             return None, None, maybe_metadata, 'player', player_error
 266
 267     # livestreams have no adaptive/muxed formats:
 268     is_live = metadata['videoDetails'].get('isLive', False)
 269
 270     if not 'formats' in metadata['streamingData'] and not is_live:
 271         return None, None, metadata, 'no-url', player_error
 272
 273     formats = metadata['streamingData'].get('formats',[])
 274     adaptive = metadata['streamingData'].get('adaptiveFormats',[])
 275     stream_map = {
 276         'adaptive_video': [a for a in adaptive if a['mimeType'].startswith('video/')],
 277         'adaptive_audio': [a for a in adaptive if a['mimeType'].startswith('audio/')],
 278         'muxed': formats,
 279         'hlsManifestUrl': metadata['streamingData'].get('hlsManifestUrl'),
 280     }
 281
 282     try:
 283         url = sorted(formats, key=lambda k: k['height'], reverse=True)[0]['url']
 284     except:
 285         url = None
 286
 287     # ip-locked videos can be recovered if the proxy module is loaded:
 288     is_geolocked = 'gcr' in parse_qs(urlparse(url).query)
 289
 290     nonfatal = 'livestream' if is_live \
 291         else 'geolocked' if is_geolocked \
 292         else None
 293
 294     return url, stream_map, metadata, nonfatal, None
 295
 296 def video_metadata(metadata):
 297     if not metadata:
 298         return {}
 299
 300     meta1 = metadata['videoDetails']
 301     # With ANDROID player API, we don't get microformat => no publishDate!
 302     meta2 = metadata.get('microformat',{}).get('playerMicroformatRenderer',{})
 303
 304     # sometimes, we receive the notification so early that the length is not
 305     # yet populated. Nothing we can do about it.
 306     length = int(meta1.get('lengthSeconds',0)) or None
 307
 308     scheduled_time = metadata.get('playabilityStatus',{}) \
 309         .get('liveStreamability',{}).get('liveStreamabilityRenderer',{}) \
 310         .get('offlineSlate',{}).get('liveStreamOfflineSlateRenderer',{}) \
 311         .get('scheduledStartTime')
 312     if scheduled_time:
 313         scheduled_time = datetime.fromtimestamp(int(scheduled_time)) \
 314             .strftime("%Y-%m-%dT%H:%M:%SZ")
 315     published_at = (
 316         meta2.get('liveBroadcastDetails',{}) .get('startTimestamp') or
 317         scheduled_time or
 318         f"{meta2.get('publishDate','1970-01-01')}T00:00:00Z"
 319     )
 320
 321     # Note: 'premiere' videos have livestream=False and published= will be the
 322     # start of the premiere.
 323     return {
 324         'title': meta1['title'],
 325         'author': meta1['author'],
 326         'channel_id': meta1['channelId'],
 327         'published': published_at,
 328         'views': int(meta1['viewCount']),
 329         'length': length,
 330         'livestream': meta1['isLiveContent'],
 331         'premiere': meta1.get('isUpcoming') and not meta1['isLiveContent'],
 332     }
 333
 334 def store_video_metadata(video_id):
 335     # check if we know about it, and if not, fetch and store video metadata
 336     with sqlite3.connect(cf['global']['database']) as conn:
 337         c = conn.cursor()
 338         c.execute("SELECT 1 from videos where id = ?", (video_id,))
 339         new_video = len(c.fetchall()) < 1
 340         if new_video:
 341             _, _, meta, _, _ = get_video_info(video_id, metaOnly=True)
 342             if meta:
 343                 meta = video_metadata(meta)
 344                 c.execute("""
 345                     INSERT OR IGNORE INTO videos (id, channel_id, title, length, livestream, premiere, published, crawled)
 346                                    VALUES (?, ?, ?, ?, ?, ?, datetime(?), datetime(?))
 347                 """, (
 348                     video_id,
 349                     meta['channel_id'],
 350                     meta['title'],
 351                     meta['length'],
 352                     meta['livestream'],
 353                     meta['premiere'],
 354                     meta['published'],
 355                     meta['published'],
 356                 ))
 357                 c.execute("""
 358                     INSERT OR REPLACE INTO channels (id, name)
 359                                     VALUES (?, ?)
 360                 """, (meta['channel_id'], meta['author']))
 361
 362 def fetch_video_flags(token, video_ids):
 363     with sqlite3.connect(cf['global']['database']) as conn:
 364         c = conn.cursor()
 365         c.execute("""
 366             SELECT video_id,display
 367               FROM flags
 368              WHERE user = ?
 369                AND display IS NOT NULL
 370                AND video_id IN ({})
 371                -- AND display = 'pinned'
 372         """.format(",".join(["?"]*len(video_ids))), (token,*video_ids))
 373         flags = c.fetchall()
 374         pinned = [video for video,disp in flags if disp == 'pinned']
 375         hidden = [video for video,disp in flags if disp == 'hidden']
 376
 377         return pinned, hidden
 378
 379 from werkzeug.exceptions import NotFound
 380 class NoFallbackException(NotFound): pass
 381 def fallback_route(*args, **kwargs): # TODO: worthy as a flask-extension?
 382     """
 383     finds the next route that matches the current url rule, and executes it.
 384     args, kwargs: pass all arguments of the current route
 385     """
 386     from flask import current_app, request, g
 387
 388     # build a list of endpoints that match the current request's url rule:
 389     matching = [
 390         rule.endpoint
 391         for rule in current_app.url_map.iter_rules()
 392         if rule.rule == request.url_rule.rule
 393     ]
 394     current = matching.index(request.endpoint)
 395
 396     # since we can't change request.endpoint, we always get the original
 397     # endpoint back. so for repeated fall throughs, we use the g object to
 398     # increment how often we want to fall through.
 399     if not '_fallback_next' in g:
 400         g._fallback_next = 0
 401     g._fallback_next += 1
 402
 403     next_ep = current + g._fallback_next
 404
 405     if next_ep < len(matching):
 406         return current_app.view_functions[matching[next_ep]](*args, **kwargs)
 407     else:
 408         raise NoFallbackException
 409
 410 def websub_url_hmac(key, feed_id, timestamp, nonce):
 411     """ generate sha1 hmac, as required by websub/pubsubhubbub """
 412     sig_input = f"{feed_id}:{timestamp}:{nonce}".encode('ascii')
 413     return hmac.new(key.encode('ascii'), sig_input, hashlib.sha1).hexdigest()
 414
 415 def websub_body_hmac(key, body):
 416     return hmac.new(key.encode('ascii'), body, hashlib.sha1).hexdigest()
 417
 418 def flask_logger(msg, level="warning"):
 419     level = dict(
 420         CRITICAL=50,
 421         ERROR=40,
 422         WARNING=30,
 423         INFO=20,
 424         DEBUG=10,
 425         NOTSET=0,
 426     ).get(level.upper(), 0)
 427     try:
 428         from flask import current_app
 429         current_app.logger.log(level, msg)
 430     except:
 431         pass
 432
 433 def pp(*args):
 434     from pprint import pprint
 435     import sys, codecs
 436     pprint(args, stream=codecs.getwriter("utf-8")(sys.stderr.buffer))