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 is_agegated(metadata):
 207     playabilityStatus = metadata['playabilityStatus']
 208     return bool(
 209         playabilityStatus.get("status") == "CONTENT_CHECK_REQUIRED"
 210         or playabilityStatus.get("desktopLegacyAgeGateReason")
 211     )
 212
 213 def get_video_info(video_id, *, metaOnly=False, _embed=True):
 214     """
 215     returns: best-quality muxed video stream, stream map, player_response, error-type/mesage
 216     error types: player, malformed, livestream, geolocked, agegated, no-url, exhausted
 217     """
 218     player_error, metadata = None, None # for 'exhausted'
 219     with sqlite3.connect(cf['global']['database']) as conn:
 220         c = conn.cursor()
 221         c.execute("SELECT * FROM captcha_cookies")
 222         cookies = dict(c.fetchall())
 223     today = datetime.now(timezone.utc).strftime("%Y%m%d")
 224     # XXX: anticaptcha hasn't been adapted
 225     key = "AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8"
 226     r = requests.post("https://www.youtube-nocookie.com/youtubei/v1/player", params={'key': key}, json={
 227         'videoId': video_id,
 228         'context': {
 229             'client': {
 230                 'gl': 'US',
 231                 'hl': 'en',
 232                 # ANDROID returns streams that are not throttled or cipher-scambled, but less metadata than WEB.
 233                 # TVHTML5* returns throttled and possibly ciphered streams, but bypasses age-gate. we don't decode them currently.
 234                 'clientName': ('ANDROID' if _embed else 'TVHTML5_SIMPLY_EMBEDDED_PLAYER') if not metaOnly else 'WEB',
 235                 'clientVersion': (f'16.20' if _embed else '2.0') if not metaOnly else f'2.{today}.01.01',
 236             },
 237             'thirdParty': {'embedUrl': 'https://www.youtube.com/'}
 238         },
 239     }, cookies=cookies)
 240
 241     if not r or r.status_code == 429:
 242         return None, None, None, 'banned', 'possible IP ban'
 243
 244     metadata = r.json()
 245     if "error" in metadata:
 246         return None, None, metadata, "malformed", metadata.get("error",{}).get("message","")
 247     playabilityStatus = metadata['playabilityStatus']['status']
 248     if playabilityStatus != "OK":
 249         playabilityReason = metadata['playabilityStatus'].get('reason',
 250                 '//'.join(metadata['playabilityStatus'].get('messages',[])))
 251         player_error = f"{playabilityStatus}: {playabilityReason}"
 252         if (is_agegated(metadata)
 253             and not metaOnly # only need metadata (e.g. called from pubsubhubbub)
 254             and _embed # already trying bypass
 255         ):
 256             _, _, metadata_embed, error_embed, errormsg_embed = get_video_info(video_id, _embed=False)
 257             if not error_embed or error_embed in ('livestream','geolocked'):
 258                 metadata = metadata_embed
 259             elif is_agegated(metadata_embed): # agegate bypass failed?
 260                 return None, None, metadata, 'agegated', player_error
 261             else:
 262                 return None, None, metadata, error_embed, errormsg_embed
 263         else:
 264             # without videoDetails, there's only the error message
 265             maybe_metadata = metadata if 'videoDetails' in metadata else None
 266             return None, None, maybe_metadata, 'player', player_error
 267
 268     # livestreams have no adaptive/muxed formats:
 269     is_live = metadata['videoDetails'].get('isLive', False)
 270
 271     if not 'formats' in metadata['streamingData'] and not is_live:
 272         return None, None, metadata, 'no-url', player_error
 273
 274     formats = metadata['streamingData'].get('formats',[])
 275     adaptive = metadata['streamingData'].get('adaptiveFormats',[])
 276     stream_map = {
 277         'adaptive_video': [a for a in adaptive if a['mimeType'].startswith('video/')],
 278         'adaptive_audio': [a for a in adaptive if a['mimeType'].startswith('audio/')],
 279         'muxed': formats,
 280         'hlsManifestUrl': metadata['streamingData'].get('hlsManifestUrl'),
 281     }
 282
 283     try:
 284         url = sorted(formats, key=lambda k: k['height'], reverse=True)[0]['url']
 285
 286         # ip-locked videos can be recovered if the proxy module is loaded:
 287         is_geolocked = 'gcr' in parse_qs(urlparse(url).query)
 288     except:
 289         url = None
 290         is_geolocked = False
 291
 292     nonfatal = 'livestream' if is_live \
 293         else 'geolocked' if is_geolocked \
 294         else None
 295
 296     return url, stream_map, metadata, nonfatal, None
 297
 298 def video_metadata(metadata):
 299     if not metadata:
 300         return {}
 301
 302     meta1 = metadata['videoDetails']
 303     # With ANDROID player API, we don't get microformat => no publishDate!
 304     meta2 = metadata.get('microformat',{}).get('playerMicroformatRenderer',{})
 305
 306     # sometimes, we receive the notification so early that the length is not
 307     # yet populated. Nothing we can do about it.
 308     length = int(meta2.get('lengthSeconds',0)) or int(meta1.get('lengthSeconds',0)) or None
 309
 310     scheduled_time = metadata.get('playabilityStatus',{}) \
 311         .get('liveStreamability',{}).get('liveStreamabilityRenderer',{}) \
 312         .get('offlineSlate',{}).get('liveStreamOfflineSlateRenderer',{}) \
 313         .get('scheduledStartTime')
 314     if scheduled_time:
 315         scheduled_time = datetime.fromtimestamp(int(scheduled_time)) \
 316             .strftime("%Y-%m-%dT%H:%M:%SZ")
 317     published_at = (
 318         meta2.get('liveBroadcastDetails',{}) .get('startTimestamp') or
 319         scheduled_time or
 320         f"{meta2.get('publishDate','1970-01-01')}T00:00:00Z"
 321     )
 322
 323     # Note: 'premiere' videos have livestream=False and published= will be the
 324     # start of the premiere.
 325     return {
 326         'title': meta1['title'],
 327         'author': meta1['author'],
 328         'channel_id': meta1['channelId'],
 329         'published': published_at,
 330         'views': int(meta1['viewCount']),
 331         'length': length,
 332         'livestream': meta1['isLiveContent'],
 333         'premiere': meta1.get('isUpcoming') and not meta1['isLiveContent'],
 334     }
 335
 336 def store_video_metadata(video_id):
 337     # check if we know about it, and if not, fetch and store video metadata
 338     with sqlite3.connect(cf['global']['database']) as conn:
 339         c = conn.cursor()
 340         c.execute("SELECT 1 from videos where id = ?", (video_id,))
 341         new_video = len(c.fetchall()) < 1
 342         if new_video:
 343             _, _, meta, _, _ = get_video_info(video_id, metaOnly=True)
 344             if meta:
 345                 meta = video_metadata(meta)
 346                 c.execute("""
 347                     INSERT OR IGNORE INTO videos (id, channel_id, title, length, livestream, premiere, published, crawled)
 348                                    VALUES (?, ?, ?, ?, ?, ?, datetime(?), datetime(?))
 349                 """, (
 350                     video_id,
 351                     meta['channel_id'],
 352                     meta['title'],
 353                     meta['length'],
 354                     meta['livestream'],
 355                     meta['premiere'],
 356                     meta['published'],
 357                     meta['published'],
 358                 ))
 359                 c.execute("""
 360                     INSERT OR REPLACE INTO channels (id, name)
 361                                     VALUES (?, ?)
 362                 """, (meta['channel_id'], meta['author']))
 363
 364 def fetch_video_flags(token, video_ids):
 365     with sqlite3.connect(cf['global']['database']) as conn:
 366         c = conn.cursor()
 367         c.execute("""
 368             SELECT video_id,display
 369               FROM flags
 370              WHERE user = ?
 371                AND display IS NOT NULL
 372                AND video_id IN ({})
 373                -- AND display = 'pinned'
 374         """.format(",".join(["?"]*len(video_ids))), (token,*video_ids))
 375         flags = c.fetchall()
 376         pinned = [video for video,disp in flags if disp == 'pinned']
 377         hidden = [video for video,disp in flags if disp == 'hidden']
 378
 379         return pinned, hidden
 380
 381 from werkzeug.exceptions import NotFound
 382 class NoFallbackException(NotFound): pass
 383 def fallback_route(*args, **kwargs): # TODO: worthy as a flask-extension?
 384     """
 385     finds the next route that matches the current url rule, and executes it.
 386     args, kwargs: pass all arguments of the current route
 387     """
 388     from flask import current_app, request, g
 389
 390     # build a list of endpoints that match the current request's url rule:
 391     matching = [
 392         rule.endpoint
 393         for rule in current_app.url_map.iter_rules()
 394         if rule.rule == request.url_rule.rule
 395     ]
 396     current = matching.index(request.endpoint)
 397
 398     # since we can't change request.endpoint, we always get the original
 399     # endpoint back. so for repeated fall throughs, we use the g object to
 400     # increment how often we want to fall through.
 401     if not '_fallback_next' in g:
 402         g._fallback_next = 0
 403     g._fallback_next += 1
 404
 405     next_ep = current + g._fallback_next
 406
 407     if next_ep < len(matching):
 408         return current_app.view_functions[matching[next_ep]](*args, **kwargs)
 409     else:
 410         raise NoFallbackException
 411
 412 def websub_url_hmac(key, feed_id, timestamp, nonce):
 413     """ generate sha1 hmac, as required by websub/pubsubhubbub """
 414     sig_input = f"{feed_id}:{timestamp}:{nonce}".encode('ascii')
 415     return hmac.new(key.encode('ascii'), sig_input, hashlib.sha1).hexdigest()
 416
 417 def websub_body_hmac(key, body):
 418     return hmac.new(key.encode('ascii'), body, hashlib.sha1).hexdigest()
 419
 420 def flask_logger(msg, level="warning"):
 421     level = dict(
 422         CRITICAL=50,
 423         ERROR=40,
 424         WARNING=30,
 425         INFO=20,
 426         DEBUG=10,
 427         NOTSET=0,
 428     ).get(level.upper(), 0)
 429     try:
 430         from flask import current_app
 431         current_app.logger.log(level, msg)
 432     except:
 433         pass
 434
 435 def pp(*args):
 436     from pprint import pprint
 437     import sys, codecs
 438     pprint(args, stream=codecs.getwriter("utf-8")(sys.stderr.buffer))