Rfactorization. Just a start...

6 files changed, 501 insertions, 0 deletions

diff --git a/web/lib/__init__.py b/web/lib/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/web/lib/__init__.py
diff --git a/web/lib/article_utils.py b/web/lib/article_utils.py
new file mode 100644
index 00000000..02ca2cd1
--- /dev/null
+++ b/web/lib/article_utils.py
@@ -0,0 +1,74 @@
+import logging
+import requests
+import dateutil.parser
+from datetime import datetime
+
+import conf
+from web.lib.utils import to_hash
+
+logger = logging.getLogger(__name__)
+
+
+def extract_id(entry, keys=[('link', 'link'), ('published', 'date'),
+                            ('updated', 'date')], force_id=False):
+    """For a given entry will return a dict that allows to identify it. The
+    dict will be constructed on the uid of the entry. if that identifier is
+    absent, the dict will be constructed upon the values of "keys".
+    """
+    entry_id = entry.get('entry_id') or entry.get('id')
+    if entry_id:
+        return {'entry_id': entry_id}
+    if not entry_id and force_id:
+        return to_hash("".join(entry[entry_key] for _, entry_key in keys
+                                   if entry_key in entry).encode('utf8'))
+    else:
+        ids = {}
+        for entry_key, pyagg_key in keys:
+            if entry_key in entry and pyagg_key not in ids:
+                ids[pyagg_key] = entry[entry_key]
+                if 'date' in pyagg_key:
+                    ids[pyagg_key] = dateutil.parser.parse(ids[pyagg_key])\
+                                                    .isoformat()
+        return ids
+
+
+def construct_article(entry, feed):
+    if hasattr(feed, 'dump'):  # this way can be a sqlalchemy obj or a dict
+        feed = feed.dump()
+    "Safe method to transorm a feedparser entry into an article"
+    now = datetime.now()
+    date = None
+    for date_key in ('published', 'updated'):
+        if entry.get(date_key):
+            try:
+                date = dateutil.parser.parse(entry[date_key])
+            except Exception:
+                pass
+            else:
+                break
+    content = ''
+    if entry.get('content'):
+        content = entry['content'][0]['value']
+    elif entry.get('summary'):
+        content = entry['summary']
+
+    article_link = entry.get('link')
+    if conf.RESOLVE_ARTICLE_URL and article_link:
+        try:
+            # resolves URL behind proxies
+            # (like feedproxy.google.com)
+            response = requests.get(article_link, verify=False, timeout=5.0)
+            article_link = response.url
+        except Exception as error:
+            logger.warning("Unable to get the real URL of %s. Error: %s",
+                           article_link, error)
+
+    return {'feed_id': feed['id'],
+            'user_id': feed['user_id'],
+            'entry_id': extract_id(entry).get('entry_id', None),
+            'link': entry.get('link', feed['site_link']),
+            'title': entry.get('title', 'No title'),
+            'readed': False, 'like': False,
+            'content': content,
+            'retrieved_date': now.isoformat(),
+            'date': (date or now).isoformat()}
diff --git a/web/lib/crawler.py b/web/lib/crawler.py
new file mode 100644
index 00000000..90a268e8
--- /dev/null
+++ b/web/lib/crawler.py
@@ -0,0 +1,252 @@
+"""
+Here's a sum up on how it works :
+
+CrawlerScheduler.run
+    will retreive a list of feeds to be refreshed and pass result to
+CrawlerScheduler.callback
+    which will retreive each feed and treat result with
+FeedCrawler.callback
+    which will interprete the result (status_code, etag) collect ids
+    and match them agaisnt pyagg which will cause
+PyAggUpdater.callback
+    to create the missing entries
+"""
+
+import time
+import conf
+import json
+import logging
+import feedparser
+from datetime import datetime, timedelta
+from functools import wraps
+from time import strftime, gmtime
+from concurrent.futures import ThreadPoolExecutor
+from requests_futures.sessions import FuturesSession
+from web.lib.utils import default_handler, to_hash
+from web.lib.feed_utils import construct_feed_from
+from web.lib.article_utils import extract_id, construct_article
+
+logger = logging.getLogger(__name__)
+logging.captureWarnings(True)
+API_ROOT = "api/v2.0/"
+
+
+class AbstractCrawler:
+
+    def __init__(self, auth, pool=None, session=None):
+        self.auth = auth
+        self.pool = pool or ThreadPoolExecutor(max_workers=conf.NB_WORKER)
+        self.session = session or FuturesSession(executor=self.pool)
+        self.session.verify = False
+        self.url = conf.PLATFORM_URL
+
+    def query_pyagg(self, method, urn, data=None):
+        """A wrapper for internal call, method should be ones you can find
+        on requests (header, post, get, options, ...), urn the distant
+        resources you want to access on pyagg, and data, the data you wanna
+        transmit."""
+        if data is None:
+            data = {}
+        method = getattr(self.session, method)
+        return method("%s%s%s" % (self.url, API_ROOT, urn),
+                      auth=self.auth, data=json.dumps(data,
+                                                      default=default_handler),
+                      headers={'Content-Type': 'application/json',
+                               'User-Agent': 'jarr'})
+
+    def wait(self, max_wait=300, checks=5, wait_for=2):
+        checked, second_waited = 0, 0
+        while True:
+            time.sleep(wait_for)
+            second_waited += wait_for
+            if second_waited > max_wait:
+                logger.warn('Exiting after %d seconds', second_waited)
+                break
+            if self.pool._work_queue.qsize():
+                checked = 0
+                continue
+            checked += 1
+            if checked == checks:
+                break
+
+
+class PyAggUpdater(AbstractCrawler):
+
+    def __init__(self, feed, entries, headers, parsed_feed,
+                 auth, pool=None, session=None):
+        self.feed = feed
+        self.entries = entries
+        self.headers = headers
+        self.parsed_feed = parsed_feed
+        super().__init__(auth, pool, session)
+
+    def callback(self, response):
+        """Will process the result from the challenge, creating missing article
+        and updating the feed"""
+        article_created = False
+        if response.result().status_code != 204:
+            results = response.result().json()
+            logger.debug('%r %r - %d entries were not matched '
+                         'and will be created',
+                         self.feed['id'], self.feed['title'], len(results))
+            for id_to_create in results:
+                article_created = True
+                entry = construct_article(
+                        self.entries[tuple(sorted(id_to_create.items()))],
+                        self.feed)
+                logger.info('%r %r - creating %r for %r - %r', self.feed['id'],
+                            self.feed['title'], entry['title'],
+                            entry['user_id'], id_to_create)
+                self.query_pyagg('post', 'article', entry)
+
+        logger.debug('%r %r - updating feed etag %r last_mod %r',
+                     self.feed['id'], self.feed['title'],
+                     self.headers.get('etag', ''),
+                     self.headers.get('last-modified', ''))
+
+        up_feed = {'error_count': 0, 'last_error': None,
+                   'etag': self.headers.get('etag', ''),
+                   'last_modified': self.headers.get('last-modified',
+                                    strftime('%a, %d %b %Y %X %Z', gmtime()))}
+        fresh_feed = construct_feed_from(url=self.feed['link'],
+                                         fp_parsed=self.parsed_feed)
+        for key in ('description', 'site_link', 'icon_url'):
+            if fresh_feed.get(key) and fresh_feed[key] != self.feed.get(key):
+                up_feed[key] = fresh_feed[key]
+        if not self.feed.get('title'):
+            up_feed['title'] = fresh_feed.get('title', '')
+        up_feed['user_id'] = self.feed['user_id']
+        # re-getting that feed earlier since new entries appeared
+        if article_created:
+            up_feed['last_retrieved'] \
+                    = (datetime.now() - timedelta(minutes=45)).isoformat()
+
+        diff_keys = {key for key in up_feed
+                     if up_feed[key] != self.feed.get(key)}
+        if not diff_keys:
+            return  # no change in the feed, no update
+        if not article_created and diff_keys == {'last_modified', 'etag'}:
+            return  # meaningless if no new article has been published
+        logger.info('%r %r - pushing feed attrs %r',
+                self.feed['id'], self.feed['title'],
+                {key: "%s -> %s" % (up_feed[key], self.feed.get(key))
+                 for key in up_feed if up_feed[key] != self.feed.get(key)})
+
+        future = self.query_pyagg('put', 'feed/%d' % self.feed['id'], up_feed)
+
+
+class FeedCrawler(AbstractCrawler):
+
+    def __init__(self, feed, auth, pool=None, session=None):
+        self.feed = feed
+        super().__init__(auth, pool, session)
+
+    def clean_feed(self):
+        """Will reset the errors counters on a feed that have known errors"""
+        if self.feed.get('error_count') or self.feed.get('last_error'):
+            future = self.query_pyagg('put', 'feed/%d' % self.feed['id'],
+                                      {'error_count': 0, 'last_error': ''})
+
+    def callback(self, response):
+        """will fetch the feed and interprete results (304, etag) or will
+        challenge pyagg to compare gotten entries with existing ones"""
+        try:
+            response = response.result()
+            response.raise_for_status()
+        except Exception as error:
+            error_count = self.feed['error_count'] + 1
+            logger.error('%r %r - an error occured while fetching '
+                         'feed; bumping  error count to %r', self.feed['id'],
+                         self.feed['title'], error_count)
+            future = self.query_pyagg('put', 'feed/%d' % self.feed['id'],
+                                      {'error_count': error_count,
+                                       'last_error': str(error),
+                                       'user_id': self.feed['user_id']})
+            return
+
+        if response.status_code == 304:
+            logger.info("%r %r - feed responded with 304",
+                        self.feed['id'], self.feed['title'])
+            self.clean_feed()
+            return
+        if 'etag' not in response.headers:
+            logger.debug('%r %r - manually generating etag',
+                         self.feed['id'], self.feed['title'])
+            response.headers['etag'] = 'pyagg/"%s"' % to_hash(response.text)
+        if response.headers['etag'] and self.feed['etag'] \
+                and response.headers['etag'] == self.feed['etag']:
+            if 'pyagg' in self.feed['etag']:
+                logger.info("%r %r - calculated hash matches (%d)",
+                            self.feed['id'], self.feed['title'],
+                            response.status_code)
+            else:
+                logger.info("%r %r - feed responded with same etag (%d)",
+                            self.feed['id'], self.feed['title'],
+                            response.status_code)
+            self.clean_feed()
+            return
+        else:
+            logger.debug('%r %r - etag mismatch %r != %r',
+                         self.feed['id'], self.feed['title'],
+                         response.headers['etag'], self.feed['etag'])
+        logger.info('%r %r - cache validation failed, challenging entries',
+                    self.feed['id'], self.feed['title'])
+
+        ids, entries = [], {}
+        parsed_response = feedparser.parse(response.content)
+        for entry in parsed_response['entries']:
+            entry_ids = extract_id(entry)
+            entry_ids['feed_id'] = self.feed['id']
+            entry_ids['user_id'] = self.feed['user_id']
+            entries[tuple(sorted(entry_ids.items()))] = entry
+            ids.append(entry_ids)
+        logger.debug('%r %r - found %d entries %r',
+                     self.feed['id'], self.feed['title'], len(ids), ids)
+        future = self.query_pyagg('get', 'articles/challenge', {'ids': ids})
+        updater = PyAggUpdater(self.feed, entries, response.headers,
+                               parsed_response,
+                               self.auth, self.pool, self.session)
+        future.add_done_callback(updater.callback)
+
+
+class CrawlerScheduler(AbstractCrawler):
+
+    def __init__(self, username, password, pool=None, session=None):
+        self.auth = (username, password)
+        super(CrawlerScheduler, self).__init__(self.auth, pool, session)
+
+    def prepare_headers(self, feed):
+        """For a known feed, will construct some header dictionnary"""
+        headers = {'User-Agent': 'jarr/crawler'}
+        if feed.get('last_modified'):
+            headers['If-Modified-Since'] = feed['last_modified']
+        if feed.get('etag') and 'pyagg' not in feed['etag']:
+            headers['If-None-Match'] = feed['etag']
+        logger.debug('%r %r - calculated headers %r',
+                     feed['id'], feed['title'], headers)
+        return headers
+
+    def callback(self, response):
+        """processes feeds that need to be fetched"""
+        response = response.result()
+        response.raise_for_status()
+        if response.status_code == 204:
+            logger.debug("No feed to fetch")
+            return
+        feeds = response.json()
+        logger.debug('%d to fetch %r', len(feeds), feeds)
+        for feed in feeds:
+            logger.debug('%r %r - fetching resources',
+                         feed['id'], feed['title'])
+            future = self.session.get(feed['link'],
+                                      headers=self.prepare_headers(feed))
+
+            feed_crwlr = FeedCrawler(feed, self.auth, self.pool, self.session)
+            future.add_done_callback(feed_crwlr.callback)
+
+    def run(self, **kwargs):
+        """entry point, will retreive feeds to be fetch
+        and launch the whole thing"""
+        logger.debug('retreving fetchable feed')
+        future = self.query_pyagg('get', 'feeds/fetchable', kwargs)
+        future.add_done_callback(self.callback)
diff --git a/web/lib/feed_utils.py b/web/lib/feed_utils.py
new file mode 100644
index 00000000..f39fe693
--- /dev/null
+++ b/web/lib/feed_utils.py
@@ -0,0 +1,92 @@
+import urllib
+import logging
+import requests
+import feedparser
+from bs4 import BeautifulSoup, SoupStrainer
+
+from web.lib.utils import try_keys, try_get_icon_url, rebuild_url
+
+logger = logging.getLogger(__name__)
+
+
+def construct_feed_from(url=None, fp_parsed=None, feed=None, query_site=True):
+    if url is None and fp_parsed is not None:
+        url = fp_parsed.get('url')
+    if url is not None and fp_parsed is None:
+        try:
+            response = requests.get(url, verify=False)
+            fp_parsed = feedparser.parse(response.content,
+                                         request_headers=response.headers)
+        except Exception:
+            logger.exception('failed to retreive that url')
+            fp_parsed = {'bozo': True}
+    assert url is not None and fp_parsed is not None
+    feed = feed or {}
+    feed_split = urllib.parse.urlsplit(url)
+    site_split = None
+    if not fp_parsed['bozo']:
+        feed['link'] = url
+        feed['site_link'] = try_keys(fp_parsed['feed'], 'href', 'link')
+        feed['title'] = fp_parsed['feed'].get('title')
+        feed['description'] = try_keys(fp_parsed['feed'], 'subtitle', 'title')
+        feed['icon_url'] = try_keys(fp_parsed['feed'], 'icon')
+    else:
+        feed['site_link'] = url
+
+    if feed.get('site_link'):
+        feed['site_link'] = rebuild_url(feed['site_link'], feed_split)
+        site_split = urllib.parse.urlsplit(feed['site_link'])
+
+    if feed.get('icon_url'):
+        feed['icon_url'] = try_get_icon_url(
+                feed['icon_url'], site_split, feed_split)
+        if feed['icon_url'] is None:
+            del feed['icon_url']
+
+    if not feed.get('site_link') or not query_site \
+            or all(bool(feed.get(k)) for k in ('link', 'title', 'icon_url')):
+        return feed
+
+    response = requests.get(feed['site_link'], verify=False)
+    bs_parsed = BeautifulSoup(response.content, 'html.parser',
+                              parse_only=SoupStrainer('head'))
+
+    if not feed.get('title'):
+        try:
+            feed['title'] = bs_parsed.find_all('title')[0].text
+        except Exception:
+            pass
+
+    def check_keys(**kwargs):
+        def wrapper(elem):
+            for key, vals in kwargs.items():
+                if not elem.has_attr(key):
+                    return False
+                if not all(val in elem.attrs[key] for val in vals):
+                    return False
+            return True
+        return wrapper
+
+    if not feed.get('icon_url'):
+        icons = bs_parsed.find_all(check_keys(rel=['icon', 'shortcut']))
+        if not len(icons):
+            icons = bs_parsed.find_all(check_keys(rel=['icon']))
+        if len(icons) >= 1:
+            for icon in icons:
+                feed['icon_url'] = try_get_icon_url(icon.attrs['href'],
+                                                    site_split, feed_split)
+                if feed['icon_url'] is not None:
+                    break
+
+        if feed.get('icon_url') is None:
+            feed['icon_url'] = try_get_icon_url('/favicon.ico',
+                                                site_split, feed_split)
+        if 'icon_url' in feed and feed['icon_url'] is None:
+            del feed['icon_url']
+
+    if not feed.get('link'):
+        alternates = bs_parsed.find_all(check_keys(rel=['alternate'],
+                type=['application/rss+xml']))
+        if len(alternates) >= 1:
+            feed['link'] = rebuild_url(alternates[0].attrs['href'], feed_split)
+    return feed
diff --git a/web/lib/utils.py b/web/lib/utils.py
new file mode 100644
index 00000000..aa552a12
--- /dev/null
+++ b/web/lib/utils.py
@@ -0,0 +1,57 @@
+import types
+import urllib
+import logging
+import requests
+from hashlib import md5
+
+logger = logging.getLogger(__name__)
+
+
+def default_handler(obj):
+    """JSON handler for default query formatting"""
+    if hasattr(obj, 'isoformat'):
+        return obj.isoformat()
+    if hasattr(obj, 'dump'):
+        return obj.dump()
+    if isinstance(obj, (set, frozenset, types.GeneratorType)):
+        return list(obj)
+    if isinstance(obj, BaseException):
+        return str(obj)
+    raise TypeError("Object of type %s with value of %r "
+                    "is not JSON serializable" % (type(obj), obj))
+
+
+def try_keys(dico, *keys):
+    for key in keys:
+        if key in dico:
+            return dico[key]
+    return
+
+
+def rebuild_url(url, base_split):
+    split = urllib.parse.urlsplit(url)
+    if split.scheme and split.netloc:
+        return url  # url is fine
+    new_split = urllib.parse.SplitResult(
+            scheme=split.scheme or base_split.scheme,
+            netloc=split.netloc or base_split.netloc,
+            path=split.path, query='', fragment='')
+    return urllib.parse.urlunsplit(new_split)
+
+
+def try_get_icon_url(url, *splits):
+    for split in splits:
+        if split is None:
+            continue
+        rb_url = rebuild_url(url, split)
+        response = requests.get(rb_url, verify=False, timeout=10)
+        # if html in content-type, we assume it's a fancy 404 page
+        content_type = response.headers.get('content-type', '')
+        if response.ok and 'html' not in content_type and response.content:
+            return response.url
+    return None
+
+
+def to_hash(text):
+    return md5(text.encode('utf8') if hasattr(text, 'encode') else text)\
+            .hexdigest()
diff --git a/web/lib/view_utils.py b/web/lib/view_utils.py
new file mode 100644
index 00000000..d4c119da
--- /dev/null
+++ b/web/lib/view_utils.py
@@ -0,0 +1,26 @@
+from functools import wraps
+from flask import request, Response, make_response
+from web.lib.utils import to_hash
+
+
+def etag_match(func):
+    @wraps(func)
+    def wrapper(*args, **kwargs):
+        response = func(*args, **kwargs)
+        if isinstance(response, Response):
+            etag = to_hash(response.data)
+            headers = response.headers
+        elif type(response) is str:
+            etag = to_hash(response)
+            headers = {}
+        else:
+            return response
+        if request.headers.get('if-none-match') == etag:
+            response = Response(status=304)
+            response.headers['Cache-Control'] \
+                    = headers.get('Cache-Control', 'pragma: no-cache')
+        elif not isinstance(response, Response):
+            response = make_response(response)
+        response.headers['etag'] = etag
+        return response
+    return wrapper