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