NewsBlur/apps/notifications/models.py

import datetime
import enum
import redis
import mongoengine as mongo
import boto
from django.conf import settings
from django.contrib.auth.models import User
from django.contrib.sites.models import Site
from django.template.loader import render_to_string
from django.core.mail import EmailMultiAlternatives
# from django.utils.html import strip_tags
from apps.rss_feeds.models import MStory, Feed
from apps.reader.models import UserSubscription
from apps.analyzer.models import MClassifierTitle, MClassifierAuthor, MClassifierFeed, MClassifierTag
from apps.analyzer.models import compute_story_score
from utils.story_functions import truncate_chars
from utils import log as logging
from utils import mongoengine_fields
from HTMLParser import HTMLParser
from vendor.apns import APNs, Payload
from BeautifulSoup import BeautifulSoup, Tag
import types
import urlparse

class NotificationFrequency(enum.Enum):
    immediately = 1
    hour_1 = 2
    hour_6 = 3
    hour_12 = 4
    hour_24 = 5

class MUserNotificationTokens(mongo.Document):
    '''A user's push notification tokens'''
    user_id                  = mongo.IntField()
    ios_tokens               = mongo.ListField(mongo.StringField(max_length=1024))
    
    meta = {
        'collection': 'notification_tokens',
        'indexes': [{'fields': ['user_id'], 
                     'unique': True,
                     'types': False, }],
        'allow_inheritance': False,
    }
    
    @classmethod
    def get_tokens_for_user(cls, user_id):
        try:
            tokens = cls.objects.get(user_id=user_id)
        except cls.DoesNotExist:
            tokens = cls.objects.create(user_id=user_id)

        return tokens

class MUserFeedNotification(mongo.Document):
    '''A user's notifications of a single feed.'''
    user_id                  = mongo.IntField()
    feed_id                  = mongo.IntField()
    frequency                = mongoengine_fields.IntEnumField(NotificationFrequency)
    is_focus                 = mongo.BooleanField()
    last_notification_date   = mongo.DateTimeField(default=datetime.datetime.now)
    is_email                 = mongo.BooleanField()
    is_web                   = mongo.BooleanField()
    is_ios                   = mongo.BooleanField()
    is_android               = mongo.BooleanField()
    ios_tokens               = mongo.ListField(mongo.StringField(max_length=1024))
    
    
    meta = {
        'collection': 'notifications',
        'indexes': ['feed_id',
                    {'fields': ['user_id', 'feed_id'], 
                     'unique': True,
                     'types': False, }],
        'allow_inheritance': False,
    }
    
    def __unicode__(self):
        notification_types = []
        if self.is_email: notification_types.append('email')
        if self.is_web: notification_types.append('web')
        if self.is_ios: notification_types.append('ios')
        if self.is_android: notification_types.append('android')

        return "%s/%s: %s -> %s" % (
            User.objects.get(pk=self.user_id).username,
            Feed.get_by_id(self.feed_id),
            ','.join(notification_types),
            self.last_notification_date,
        )
    
    @classmethod
    def feed_has_users(cls, feed_id):
        return cls.users_for_feed(feed_id).count()
    
    @classmethod
    def users_for_feed(cls, feed_id):
        notifications = cls.objects.filter(feed_id=feed_id)
    
        return notifications
    
    @classmethod
    def feeds_for_user(cls, user_id):
        notifications = cls.objects.filter(user_id=user_id)
        notifications_by_feed = {}

        for feed in notifications:
            notifications_by_feed[feed.feed_id] = {
                'notification_types': [],
                'notification_filter': "focus" if feed.is_focus else "unread",
            }
            if feed.is_email: notifications_by_feed[feed.feed_id]['notification_types'].append('email')
            if feed.is_web: notifications_by_feed[feed.feed_id]['notification_types'].append('web')
            if feed.is_ios: notifications_by_feed[feed.feed_id]['notification_types'].append('ios')
            if feed.is_android: notifications_by_feed[feed.feed_id]['notification_types'].append('android')
            
        return notifications_by_feed
    
    @classmethod
    def push_feed_notifications(cls, feed_id, new_stories, force=False):
        feed = Feed.get_by_id(feed_id)
        notifications = MUserFeedNotification.users_for_feed(feed.pk)
        logging.debug("   ---> [%-30s] ~FCPushing out notifications to ~SB%s users~SN for ~FB~SB%s stories" % (
                      feed, len(notifications), new_stories))
        r = redis.Redis(connection_pool=settings.REDIS_STORY_HASH_POOL)
        
        latest_story_hashes = r.zrange("zF:%s" % feed.pk, -1 * new_stories, -1)
        mstories = MStory.objects.filter(story_hash__in=latest_story_hashes).order_by('-story_date')
        stories = Feed.format_stories(mstories)
        total_sent_count = 0
        
        for user_feed_notification in notifications:
            sent_count = 0
            last_notification_date = user_feed_notification.last_notification_date
            try:
                usersub = UserSubscription.objects.get(user=user_feed_notification.user_id,
                                                       feed=user_feed_notification.feed_id)
            except UserSubscription.DoesNotExist:
                continue
            classifiers = user_feed_notification.classifiers(usersub)

            if classifiers == None:
                logging.debug("Has no usersubs")
                continue

            for story in stories:
                if sent_count >= 3:
                    logging.debug("Sent too many, ignoring...")
                    continue                    
                if story['story_date'] <= last_notification_date and not force:
                    logging.debug("Story date older than last notification date: %s <= %s" % (story['story_date'], last_notification_date))
                    continue
                
                if story['story_date'] > user_feed_notification.last_notification_date:
                    user_feed_notification.last_notification_date = story['story_date']
                    user_feed_notification.save()
                
                story['story_content'] = HTMLParser().unescape(story['story_content'])
                
                sent = user_feed_notification.push_story_notification(story, classifiers, usersub)
                if sent: 
                    sent_count += 1
                    total_sent_count += 1
        return total_sent_count, len(notifications)
        
    def classifiers(self, usersub):
        classifiers = {}
        if usersub.is_trained:
            classifiers['feeds']   = list(MClassifierFeed.objects(user_id=self.user_id, feed_id=self.feed_id,
                                                                 social_user_id=0))
            classifiers['authors'] = list(MClassifierAuthor.objects(user_id=self.user_id, feed_id=self.feed_id))
            classifiers['titles']  = list(MClassifierTitle.objects(user_id=self.user_id, feed_id=self.feed_id))
            classifiers['tags']    = list(MClassifierTag.objects(user_id=self.user_id, feed_id=self.feed_id))
            
        return classifiers
    
    def title_and_body(self, story, usersub):
        def replace_with_newlines(element):
            text = ''
            for elem in element.recursiveChildGenerator():
                if isinstance(elem, types.StringTypes):
                    text += elem
                elif elem.name == 'br':
                    text += '\n'
                elif elem.name == 'p':
                    text += '\n\n'
            return text
        
        feed_title = usersub.user_title or usersub.feed.feed_title
        # title = "%s: %s" % (feed_title, story['story_title'])
        title = feed_title
        subtitle = story['story_title']
        # body = HTMLParser().unescape(strip_tags(story['story_content']))
        soup = BeautifulSoup(story['story_content'].strip())
        # print story['story_content']
        body = replace_with_newlines(soup)
        body = truncate_chars(body.strip(), 1200)
        
        return title, subtitle, body
        
    def push_story_notification(self, story, classifiers, usersub):
        story_score = self.story_score(story, classifiers)
        if self.is_focus and story_score <= 0:
            logging.debug("Is focus, but story is hidden")
            return False
        elif story_score < 0:
            logging.debug("Is unread, but story is hidden")
            return False
        
        user = User.objects.get(pk=self.user_id)
        logging.user(user, "~FCSending push notification: %s/%s (score: %s)" % (story['story_title'][:40], story['story_hash'], story_score))
        
        self.send_web(story, user)
        self.send_ios(story, user, usersub)
        self.send_android(story)
        self.send_email(story, usersub)
        
        return True
    
    def send_web(self, story, user):
        if not self.is_web: return
        
        r = redis.Redis(connection_pool=settings.REDIS_PUBSUB_POOL)
        r.publish(user.username, 'notification:%s,%s' % (story['story_hash'], story['story_title']))
    
    def send_ios(self, story, user, usersub):
        if not self.is_ios: return

        apns = APNs(use_sandbox=False, 
                    cert_file='/srv/newsblur/config/certificates/aps.pem',
                    key_file='/srv/newsblur/config/certificates/aps.pem',
                    enhanced=settings.DEBUG)
        
        tokens = MUserNotificationTokens.get_tokens_for_user(self.user_id)
        title, subtitle, body = self.title_and_body(story, usersub)
        image_url = None
        if len(story['image_urls']):
            image_url = story['image_urls'][0]
            # print image_url
        
        for token in tokens.ios_tokens:
            logging.user(user, '~BMStory notification by iOS: ~FY~SB%s~SN~BM~FY/~SB%s' % 
                                       (story['story_title'][:50], usersub.feed.feed_title[:50]))
            payload = Payload(alert={'title': title,
                                     'subtitle': subtitle,
                                     'body': body},
                              category="STORY_CATEGORY",
                              mutable_content=True,
                              custom={'story_hash': story['story_hash'],
                                      'story_feed_id': story['story_feed_id'],
                                      'image_url': image_url,
                                     })
            apns.gateway_server.send_notification(token, payload)
        
    def send_android(self, story):
        if not self.is_android: return
        
        
    def send_email(self, story, usersub):
        if not self.is_email: return
        feed = usersub.feed
        story_content = self.sanitize_story(story['story_content'])
        
        params  = {
            "story": story,
            "story_content": story_content,
            "feed": feed,
            "feed_title": usersub.user_title or feed.feed_title,
            "favicon_border": feed.favicon_color,
        }
        from_address = 'share@newsblur.com'
        to_address = '%s <%s>' % (usersub.user.username, usersub.user.email)
        text    = render_to_string('mail/email_story_notification.txt', params)
        html    = render_to_string('mail/email_story_notification.xhtml', params)
        subject = '%s: %s' % (usersub.user_title or usersub.feed.feed_title, story['story_title'])
        subject = subject.replace('\n', ' ')
        msg     = EmailMultiAlternatives(subject, text, 
                                         from_email='NewsBlur <%s>' % from_address,
                                         to=[to_address])
        msg.attach_alternative(html, "text/html")
        try:
            msg.send()
        except boto.ses.connection.ResponseError, e:
            logging.user(usersub.user, '~BMStory notification by email error: ~FR%s' % e)
        logging.user(usersub.user, '~BMStory notification by email: ~FY~SB%s~SN~BM~FY/~SB%s' % 
                                   (story['story_title'][:50], usersub.feed.feed_title[:50]))
    
    def sanitize_story(self, story_content):
        soup = BeautifulSoup(story_content.strip())
        fqdn = Site.objects.get_current().domain
        
        for iframe in soup("iframe"):
            url = dict(iframe.attrs).get('src', "")
            youtube_id = self.extract_youtube_id(url)
            if youtube_id:
                a = Tag(soup, 'a', [('href', url)])
                img = Tag(soup, 'img', [('style', "display: block; 'background-image': \"url(https://%s/img/reader/youtube_play.png), url(http://img.youtube.com/vi/%s/0.jpg)\"" % (fqdn, youtube_id)), ('src', 'http://img.youtube.com/vi/%s/0.jpg' % youtube_id)])
                a.insert(0, img)
                iframe.replaceWith(a)
            else:
                iframe.extract()
        
        return unicode(soup)
    
    def extract_youtube_id(self, url):
        youtube_id = None

        if 'youtube.com' in url:
            youtube_parts = urlparse.urlparse(url)
            if '/embed/' in youtube_parts.path:
                youtube_id = youtube_parts.path.replace('/embed/', '')
                
        return youtube_id
        
    def story_score(self, story, classifiers):
        score = compute_story_score(story, classifier_titles=classifiers.get('titles', []), 
                                    classifier_authors=classifiers.get('authors', []), 
                                    classifier_tags=classifiers.get('tags', []),
                                    classifier_feeds=classifiers.get('feeds', []))
        
        return score