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             _, _, meta, _, _ = get_video_info(video['video_id'], metaOnly=True)
 120             # The 'published' timestamp sent in websub POSTs are often wrong (e.g.:
 121             # video gets uploaded as unlisted on day A and set to public on day B;
 122             # the webhook is sent on day B, but 'published' says A. The video
 123             # therefore looks like it's just an update to an older video).
 124             # g_v_i gives is the date the video was published to viewers, so we
 125             # prefer that. But since g_v_i only returns the date without time,
 126             # we still use xmlfeed's date if it's the same date.
 127             published = dateutil.parser.parse(video['published'])
 128             length = None
 129             livestream = None
 130             if meta:
 131                 meta = video_metadata(meta)
 132                 published2 = dateutil.parser.parse(meta['published'])
 133                 if published < published2: # g_v_i date is more accurate:
 134                     published = published2
 135                 length = meta['length']
 136                 livestream = meta['livestream']
 137
 138             now = datetime.now(timezone.utc)
 139
 140             # we pretend that all videos uploaded this week were uploaded just
 141             # now, so the user sees it at the top of the feed, and it doesn't
 142             # get inserted somewhere further down.
 143             if (now - published).days < 7:
 144                 timestamp = now
 145             else:#, it's just an update to an older video.
 146                 timestamp = published
 147
 148             c.execute("""
 149                 INSERT OR IGNORE INTO videos
 150                     (id, channel_id, title, length, livestream, published, crawled)
 151                 VALUES (?, ?, ?, ?, ?, datetime(?), datetime(?))
 152             """, (
 153                 video['video_id'],
 154                 video['channel_id'],
 155                 video['title'],
 156                 length,
 157                 livestream,
 158                 video['published'],
 159                 timestamp
 160             ))
 161         else:
 162             # update video title (everything else can't change)
 163             c.execute("""
 164                 UPDATE OR IGNORE videos
 165                     SET title = ?
 166                     WHERE id = ?
 167             """, (
 168                 video['title'],
 169                 video['video_id'],
 170             ))
 171
 172         # for channels, this is obviously always the same, but playlists can
 173         # consist of videos from different channels:
 174         if i == 0 or playlist:
 175             c.execute("""
 176                 INSERT OR REPLACE INTO channels (id, name)
 177                                 VALUES (?, ?)
 178             """, (video['channel_id'], video['author']))
 179
 180         # keep track of which videos are in a playlist, so we can show the user
 181         # why a video is in their feed:
 182         if playlist:
 183             c.execute("""
 184                 INSERT OR IGNORE INTO playlist_videos (video_id, playlist_id)
 185                                VALUES (?, ?)
 186             """, (video['video_id'], playlist))
 187
 188     if playlist and not from_webhook: # Note: playlists can't get updated via websub
 189         c.execute("""
 190             INSERT OR REPLACE INTO playlists (id, name, author)
 191                             VALUES (?, ?, ?)
 192             """, (playlist, title, channel))
 193         c.execute("""
 194             INSERT OR REPLACE INTO channels (id, name)
 195                             VALUES (?, ?)
 196         """, (channel, author))
 197
 198     db.commit()
 199
 200     return True
 201
 202 def get_video_info(video_id, *, metaOnly=False, _embed=True):
 203     """
 204     returns: best-quality muxed video stream, stream map, player_response, error-type/mesage
 205     error types: player, malformed, livestream, geolocked, agegated, no-url, exhausted
 206     """
 207     player_error, metadata = None, None # for 'exhausted'
 208     with sqlite3.connect(cf['global']['database']) as conn:
 209         c = conn.cursor()
 210         c.execute("SELECT * FROM captcha_cookies")
 211         cookies = dict(c.fetchall())
 212     today = datetime.now(timezone.utc).strftime("%Y%m%d")
 213     # XXX: anticaptcha hasn't been adapted
 214     # XXX: this is not cached any more!
 215     key = "AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8"
 216     r = requests.post("https://www.youtube-nocookie.com/youtubei/v1/player", params={'key': key}, json={
 217         'videoId': video_id,
 218         'context': {
 219             'client': {
 220                 'gl': 'US',
 221                 'hl': 'en',
 222                 # ANDROID returns streams that are not throttled or cipher-scambled, but less metadata than WEB
 223                 'clientName': 'ANDROID' if not metaOnly else 'WEB',
 224                 'clientVersion': f'16.20' if not metaOnly else f'2.{today}.01.01',
 225                 **({'clientScreen': 'EMBED'} if _embed else {}),
 226             },
 227             'thirdParty': {'embedUrl': 'https://google.com'}
 228         },
 229     }, cookies=cookies)
 230
 231     if not r or r.status_code == 429:
 232         return None, None, None, 'banned', 'possible IP ban'
 233
 234     metadata = r.json()
 235     if "error" in metadata:
 236         return None, None, metadata, "malformed", metadata.get("error",{}).get("message","")
 237     playabilityStatus = metadata['playabilityStatus']['status']
 238     if playabilityStatus != "OK":
 239         playabilityReason = metadata['playabilityStatus'].get('reason',
 240                 '//'.join(metadata['playabilityStatus'].get('messages',[])))
 241         player_error = f"{playabilityStatus}: {playabilityReason}"
 242         # "Watch on YouTube" button is visible => "Playback on other websites
 243         # has been disabled by the video owner." => retry detailpage API
 244         if (playabilityStatus == "UNPLAYABLE" and
 245             'proceedButton' in metadata['playabilityStatus'] \
 246                 .get('errorScreen',{}).get('playerErrorMessageRenderer',{})
 247             and not metaOnly # only need metadata (e.g. called from pubsubhubbub)
 248             and _embed
 249
 250         ):
 251             _, _, metadata_embed, error_embed, errormsg_embed = get_video_info(video_id, _embed=False)
 252             if not error_embed or error_embed in ('livestream','geolocked'):
 253                 metadata = metadata_embed
 254             elif errormsg_embed == "LOGIN_REQUIRED: Sign in to confirm your age":
 255                 return None, None, metadata, 'agegated', player_error
 256             else:
 257                 return None, None, metadata, error_embed, errormsg_embed
 258         else:
 259             # without videoDetails, there's only the error message
 260             maybe_metadata = metadata if 'videoDetails' in metadata else None
 261             return None, None, maybe_metadata, 'player', player_error
 262
 263     # livestreams have no adaptive/muxed formats:
 264     is_live = metadata['videoDetails'].get('isLive', False)
 265
 266     if not 'formats' in metadata['streamingData'] and not is_live:
 267         return None, None, metadata, 'no-url', player_error
 268
 269     formats = metadata['streamingData'].get('formats',[])
 270     adaptive = metadata['streamingData'].get('adaptiveFormats',[])
 271     stream_map = {
 272         'adaptive_video': [a for a in adaptive if a['mimeType'].startswith('video/')],
 273         'adaptive_audio': [a for a in adaptive if a['mimeType'].startswith('audio/')],
 274         'muxed': formats,
 275         'hlsManifestUrl': metadata['streamingData'].get('hlsManifestUrl'),
 276     }
 277
 278     try:
 279         url = sorted(formats, key=lambda k: k['height'], reverse=True)[0]['url']
 280     except:
 281         url = None
 282
 283     # ip-locked videos can be recovered if the proxy module is loaded:
 284     is_geolocked = 'gcr' in parse_qs(urlparse(url).query)
 285
 286     nonfatal = 'livestream' if is_live \
 287         else 'geolocked' if is_geolocked \
 288         else None
 289
 290     return url, stream_map, metadata, nonfatal, None
 291
 292 def video_metadata(metadata):
 293     if not metadata:
 294         return {}
 295
 296     meta1 = metadata['videoDetails']
 297     # With ANDROID player API, we don't get microformat => no publishDate!
 298     meta2 = metadata.get('microformat',{}).get('playerMicroformatRenderer',{})
 299
 300     # sometimes, we receive the notification so early that the length is not
 301     # yet populated. Nothing we can do about it.
 302     length = int(meta1.get('lengthSeconds',0)) or None
 303
 304     published_at = meta2.get('liveBroadcastDetails',{}) \
 305         .get('startTimestamp', f"{meta2.get('publishDate','1970-01-01')}T00:00:00Z")
 306
 307     # Note: 'premiere' videos have livestream=False and published= will be the
 308     # start of the premiere.
 309     return {
 310         'title': meta1['title'],
 311         'author': meta1['author'],
 312         'channel_id': meta1['channelId'],
 313         'published': published_at,
 314         'views': int(meta1['viewCount']),
 315         'length': length,
 316         'livestream': meta1['isLiveContent'],
 317     }
 318
 319 def store_video_metadata(video_id):
 320     # check if we know about it, and if not, fetch and store video metadata
 321     with sqlite3.connect(cf['global']['database']) as conn:
 322         c = conn.cursor()
 323         c.execute("SELECT 1 from videos where id = ?", (video_id,))
 324         new_video = len(c.fetchall()) < 1
 325         if new_video:
 326             _, _, meta, _, _ = get_video_info(video_id, metaOnly=True)
 327             if meta:
 328                 meta = video_metadata(meta)
 329                 c.execute("""
 330                     INSERT OR IGNORE INTO videos (id, channel_id, title, length, published, crawled)
 331                                    VALUES (?, ?, ?, ?, datetime(?), datetime(?))
 332                 """, (
 333                     video_id,
 334                     meta['channel_id'],
 335                     meta['title'],
 336                     meta['length'],
 337                     meta['published'],
 338                     meta['published'],
 339                 ))
 340                 c.execute("""
 341                     INSERT OR REPLACE INTO channels (id, name)
 342                                     VALUES (?, ?)
 343                 """, (meta['channel_id'], meta['author']))
 344
 345 def fetch_video_flags(token, video_ids):
 346     with sqlite3.connect(cf['global']['database']) as conn:
 347         c = conn.cursor()
 348         c.execute("""
 349             SELECT video_id,display
 350               FROM flags
 351              WHERE user = ?
 352                AND display IS NOT NULL
 353                AND video_id IN ({})
 354                -- AND display = 'pinned'
 355         """.format(",".join(["?"]*len(video_ids))), (token,*video_ids))
 356         flags = c.fetchall()
 357         pinned = [video for video,disp in flags if disp == 'pinned']
 358         hidden = [video for video,disp in flags if disp == 'hidden']
 359
 360         return pinned, hidden
 361
 362 from werkzeug.exceptions import NotFound
 363 class NoFallbackException(NotFound): pass
 364 def fallback_route(*args, **kwargs): # TODO: worthy as a flask-extension?
 365     """
 366     finds the next route that matches the current url rule, and executes it.
 367     args, kwargs: pass all arguments of the current route
 368     """
 369     from flask import current_app, request, g
 370
 371     # build a list of endpoints that match the current request's url rule:
 372     matching = [
 373         rule.endpoint
 374         for rule in current_app.url_map.iter_rules()
 375         if rule.rule == request.url_rule.rule
 376     ]
 377     current = matching.index(request.endpoint)
 378
 379     # since we can't change request.endpoint, we always get the original
 380     # endpoint back. so for repeated fall throughs, we use the g object to
 381     # increment how often we want to fall through.
 382     if not '_fallback_next' in g:
 383         g._fallback_next = 0
 384     g._fallback_next += 1
 385
 386     next_ep = current + g._fallback_next
 387
 388     if next_ep < len(matching):
 389         return current_app.view_functions[matching[next_ep]](*args, **kwargs)
 390     else:
 391         raise NoFallbackException
 392
 393 def websub_url_hmac(key, feed_id, timestamp, nonce):
 394     """ generate sha1 hmac, as required by websub/pubsubhubbub """
 395     sig_input = f"{feed_id}:{timestamp}:{nonce}".encode('ascii')
 396     return hmac.new(key.encode('ascii'), sig_input, hashlib.sha1).hexdigest()
 397
 398 def websub_body_hmac(key, body):
 399     return hmac.new(key.encode('ascii'), body, hashlib.sha1).hexdigest()
 400
 401 def flask_logger(msg, level="warning"):
 402     level = dict(
 403         CRITICAL=50,
 404         ERROR=40,
 405         WARNING=30,
 406         INFO=20,
 407         DEBUG=10,
 408         NOTSET=0,
 409     ).get(level.upper(), 0)
 410     try:
 411         from flask import current_app
 412         current_app.logger.log(level, msg)
 413     except:
 414         pass
 415
 416 def pp(*args):
 417     from pprint import pprint
 418     import sys, codecs
 419     pprint(args, stream=codecs.getwriter("utf-8")(sys.stderr.buffer))