app/frontend.py

   1 import re
   2 import time
   3 import hmac
   4 import hashlib
   5 import sqlite3
   6 import secrets
   7 import requests
   8 from urllib.parse import parse_qs
   9 from flask import Flask, render_template, request, redirect, flash, url_for, jsonify, g
  10
  11 from common import *
  12
  13 app = Flask(__name__)
  14 app.secret_key = secrets.token_bytes(16) # XXX: generate and hard-code, or cookies and csrf-validation will fail!
  15
  16 @app.route('/')
  17 def index():
  18     return redirect(url_for('feed'), code=302)
  19
  20 @app.route('/feed/subscriptions')
  21 def feed():
  22     token = request.args.get('token', 'guest')
  23     page = int(request.args.get('page', 0))
  24     with sqlite3.connect(cf['global']['database']) as conn:
  25         c = conn.cursor()
  26         c.execute("""
  27            SELECT videos.id, channel_id, name, title, published, flags.display
  28              FROM videos
  29              JOIN channels ON videos.channel_id = channels.id
  30         LEFT JOIN flags ON (videos.id = flags.video_id) AND (flags.user = ?)
  31             WHERE channel_id IN
  32                   (SELECT channel_id FROM subscriptions WHERE user = ?)
  33                   AND flags.display IS NOT 'hidden'
  34          ORDER BY (display = 'pinned') DESC, crawled DESC
  35             LIMIT 36
  36            OFFSET 36*?""", (token, token, page))
  37         rows = [{
  38             'video_id': video_id,
  39             'channel_id': channel_id,
  40             'author': author,
  41             'title': title,
  42             'published': published,
  43             'pinned': display == 'pinned',
  44         } for (video_id, channel_id, author, title, published, display) in c.fetchall()]
  45     return render_template('index.html.j2', rows=rows, page=page)
  46
  47 @app.route('/watch')
  48 def watch():
  49     if not 'v' in request.args:
  50         return "missing video id", 400
  51
  52     plaintextheader = {'content-type': 'text/plain',"Link": "<data:text/css,body%7Bcolor:%23eee;background:%23333%7D>; rel=stylesheet;"}
  53
  54     video_id = request.args.get('v')
  55     (sts, algo) = get_cipher()
  56     (video_url, metadata, error_type, error) = get_video_info(video_id, sts, algo)
  57     if error_type in ['initial', 'player']:
  58         return error, 400, plaintextheader
  59
  60     show = request.args.get("show")
  61     if show == "raw":
  62         if error:
  63             extra = {'geolocked':'local=1', 'livestream':'raw=0'}.get(error,'')
  64             # if error==exhausted, metadata.playabilityStatus.reason may contain additional information.
  65             return f"{error.upper()}: Redirecting to Invidious.", 502, {'Refresh': f'2; URL=https://invidio.us/watch?v={video_id}&{extra}&raw=1', **plaintextheader}
  66         return redirect(video_url, code=307)
  67     elif show == "json":
  68         return jsonify(metadata)
  69     else: # todo: handle geolocked, livesteam and the case when we have an exhausted error with no metadata returned
  70         if error:
  71             err_desc = {'geolocked': "this video is geolocked", 'livestream': "livestreams not yet supported", 'exhausted': "couldn't extract video urls"}.get(error,'')
  72             flash(("error",f"{err_desc}. Watch on <a href='https://invidio.us/watch?v={video_id}'>Invidious</a> or <a href='https://www.youtube.com/watch?v={video_id}'>Youtube</a>")) # todo: cleanup
  73         return render_template('watch.html.j2', video_id=video_id, video_url=video_url, **prepare_metadata(metadata))
  74
  75 @app.route('/channel/<channel_id>')
  76 def channel(channel_id):
  77     if not re.match(r"(UC[A-Za-z0-9_-]{22})", channel_id):
  78         return "bad channel id", 400 # todo
  79
  80     xmlfeed = fetch_xml("channel_id", channel_id)
  81     if not xmlfeed:
  82         return "not found or something", 404 # XXX
  83     title, author, videos = parse_xml(xmlfeed)
  84     return render_template('xmlfeed.html.j2', title=author, rows=videos)
  85
  86 @app.route('/playlist')
  87 def playlist():
  88     playlist_id = request.args.get('list')
  89     if not playlist_id:
  90         return "bad list id", 400 # todo
  91
  92     xmlfeed = fetch_xml("playlist_id", playlist_id)
  93     if not xmlfeed:
  94         return "not found or something", 404 # XXX
  95     title, author, videos = parse_xml(xmlfeed)
  96     return render_template('xmlfeed.html.j2', title=f"{title} by {author}", rows=videos)
  97
  98 @app.route('/subscription_manager')
  99 def subscription_manager():
 100     token = request.args.get('token', 'guest')
 101     with sqlite3.connect(cf['global']['database']) as conn:
 102         #with conn.cursor() as c:
 103             c = conn.cursor()
 104             c.execute("""
 105                   SELECT subscriptions.channel_id, name,
 106                          (subscribed_until < datetime('now')) AS obsolete
 107                     FROM subscriptions
 108                     left JOIN channels ON channels.id = subscriptions.channel_id
 109                     left JOIN websub ON channels.id = websub.channel_id
 110                    WHERE user = ?
 111                 ORDER BY obsolete=0, name COLLATE NOCASE ASC""", (token,))
 112             rows = [{
 113                 'channel_id': channel_id,
 114                 'author': author or channel_id,
 115                 'subscribed_until': subscribed_until
 116             } for (channel_id, author, subscribed_until) in c.fetchall()]
 117     return render_template('subscription_manager.html.j2', rows=rows)
 118
 119 @app.route('/feed/subscriptions', methods=['POST'])
 120 def feed_post():
 121     token = request.args.get('token', 'guest')
 122     if token == 'guest': return "guest user is read-only", 403
 123     action = next(request.form.keys(), None)
 124     if action in ['pin', 'unpin', 'hide']:
 125         video_id = request.form.get(action)
 126         display = {
 127             'pin': 'pinned',
 128             'unpin': None,
 129             'hide': 'hidden',
 130         }[action]
 131         with sqlite3.connect(cf['global']['database']) as conn:
 132             #with conn.cursor() as c:
 133                 c = conn.cursor()
 134                 c.execute("""
 135                         INSERT OR REPLACE INTO flags (user, video_id, display)
 136                         VALUES (?, ?, ?)
 137                 """, (token, video_id, display))
 138     else:
 139         flash(("error","unsupported action"))
 140     return redirect(request.url, code=303)
 141
 142 @app.route('/subscription_manager', methods=['POST'])
 143 def manage_subscriptions():
 144     token = request.args.get('token', 'guest')
 145     if token == 'guest': return "guest user is read-only", 403
 146     if 'subscribe' in request.form:
 147         channel_id = request.form.get("subscribe")
 148         match = re.match(r"(UC[A-Za-z0-9_-]{22})", channel_id)
 149         if match:
 150             channel_id = match.group(1)
 151         else:
 152             match = re.match(r"((?:PL|LL|EC|UU|FL|UL|OL)[A-Za-z0-9_-]{10,})", channel_id)
 153             if match:  # NOTE: PL-playlists are 32chars, others differ in length.
 154                 flash(("error","playlists not (yet?) supported."))
 155                 return redirect(request.url, code=303) # TODO: dedup redirection
 156             else:
 157                 flash(("error","not a valid/subscribable URI"))
 158                 return redirect(request.url, code=303) # TODO: dedup redirection
 159         with sqlite3.connect(cf['global']['database']) as conn:
 160             #with conn.cursor() as c:
 161                 c = conn.cursor()
 162                 c.execute("""
 163                         INSERT OR IGNORE INTO subscriptions (user, channel_id)
 164                         VALUES (?, ?)
 165                 """, (token, channel_id))
 166                 # TODO: sql-error-handling, asynchronically calling update-subs.pl
 167
 168     elif 'unsubscribe' in request.form:
 169         with sqlite3.connect(cf['global']['database']) as conn:
 170             #with conn.cursor() as c:
 171                 c = conn.cursor()
 172                 c.execute("""
 173                         DELETE FROM subscriptions
 174                         WHERE user = ? AND channel_id = ?
 175                 """, (token, channel_id))
 176                 # TODO: sql-error-handling, report success
 177
 178     else:
 179         flash(("error","unsupported action"))
 180
 181     return redirect(request.url, code=303)
 182
 183 @app.route('/r/')
 184 def reddit_index():
 185     return ""
 186 @app.route('/r/<subreddit>')
 187 def reddit(subreddit="videos"):
 188     count = int(request.args.get('count', 0))
 189     before = request.args.get('before')
 190     after = request.args.get('after')
 191     query = '&'.join([f"{k}={v}" for k,v in [('count',count), ('before',before), ('after',after)] if v])
 192     r = requests.get(f"https://old.reddit.com/r/{subreddit}.json?{query}", headers={'User-Agent':'Mozilla/5.0'})
 193     if not r.ok or not 'data' in r.json():
 194         return r.text+"error retrieving reddit data", 502
 195
 196     good = [e for e in r.json()['data']['children'] if e['data']['score'] > 1]
 197     bad  = [e for e in r.json()['data']['children'] if e['data']['score'] <=1]
 198     videos = []
 199     for entry in (good+bad):
 200         e = entry['data']
 201         if e['domain'] not in ['youtube.com', 'youtu.be', 'invidio.us']:
 202             continue
 203         video_id = re.match(r'^https?://(?:www.|m.)?(?:youtube.com/watch\?(?:.*&amp;)?v=|youtu.be/|youtube.com/embed/)([-_0-9A-Za-z]+)', e['url']).group(1)
 204         if not video_id: continue
 205         videos.append({
 206             'video_id': video_id,
 207             'title': e['title'],
 208             'url': e['permalink'],
 209             'n_comments': e['num_comments'],
 210             'n_karma': e['score'],
 211         })
 212     before = r.json()['data']['before']
 213     after = r.json()['data']['after']
 214     return render_template('reddit.html.j2', subreddit=subreddit, rows=videos, before=before, after=after, count=count)
 215
 216 def get_cipher():
 217     # reload cipher from database every 1 hour
 218     if 'cipher' not in g or time.time() - g.get('cipher_updated', 0) > 1 * 60 * 60:
 219         with sqlite3.connect(cf['global']['database']) as conn:
 220             c = conn.cursor()
 221             c.execute("SELECT sts, algorithm FROM cipher")
 222             g.cipher = c.fetchone()
 223             g.cipher_updated = time.time()
 224
 225     return g.cipher
 226
 227 #@app.teardown_appcontext
 228 #def teardown_db():
 229 #    db = g.pop('db', None)
 230 #
 231 #    if db is not None:
 232 #        db.close()
 233
 234 # Magic CSRF protection: This modifies outgoing HTML responses and injects a csrf token into all forms.
 235 # All post requests are then checked if they contain the valid token.
 236 # TODO:
 237 # - don't use regex for injecting
 238 # - inject a http header into all responses (that could be used by apis)
 239 # - allow csrf token to be passed in http header, json, ...
 240 # - a decorator on routes to opt out of verification or output munging
 241 @app.after_request
 242 def add_csrf_protection(response):
 243     if response.mimetype == "text/html":
 244         token = hmac.new(app.secret_key, request.remote_addr.encode('ascii'), hashlib.sha256).hexdigest()  # TODO: will fail behind reverse proxy (remote_addr always localhost)
 245         response.set_data( re.sub(
 246             rb'''(<[Ff][Oo][Rr][Mm](\s+[a-zA-Z0-9-]+(=(\w*|'[^']*'|"[^"]*"))?)*>)''', # match form tags with any number of attributes and any type of quotes
 247             rb'\1<input type="hidden" name="csrf" value="'+token.encode('ascii')+rb'">', # hackily append a hidden input with our csrf protection value
 248             response.get_data()))
 249     return response
 250 @app.before_request
 251 def verify_csrf_protection():
 252     token = hmac.new(app.secret_key, request.remote_addr.encode('ascii'), hashlib.sha256).hexdigest()  # TODO: will fail behind reverse proxy (remote_addr always localhost)
 253     if request.method == "POST" and request.form.get('csrf') != token:
 254         return "CSRF validation failed!", 400
 255     request.form = request.form.copy() # make it mutable
 256     request.form.poplist('csrf')  # remove our csrf again
 257
 258 @app.template_filter('format_date')
 259 def format_date(s):
 260     (y,m,d) = (int(n) for n in s.split('T')[0].split(' ')[0].split('-'))  # iso-dates can seperate date from time with space or 'T'
 261     M = '_ Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec'.split()
 262     return f"{d} {M[m]}"
 263
 264 if __name__ == '__main__':
 265     app.run(debug=True)