NewsBlur/apps/reader/models.py

import datetime
import mongoengine as mongo
from utils import log as logging
from utils import json
from django.db import models
from django.conf import settings
from django.contrib.auth.models import User
from django.core.cache import cache
from apps.rss_feeds.models import Feed, Story, MStory
from apps.analyzer.models import MClassifierFeed, MClassifierAuthor, MClassifierTag, MClassifierTitle
from apps.analyzer.models import apply_classifier_titles, apply_classifier_feeds, apply_classifier_authors, apply_classifier_tags

class UserSubscription(models.Model):
    """
    A feed which a user has subscrubed to. Carries all of the cached information
    about the subscription, including unread counts of the three primary scores.
    
    Also has a dirty flag (needs_unread_recalc) which means that the unread counts
    are not accurate and need to be calculated with `self.calculate_feed_scores()`.
    """
    UNREAD_CUTOFF = datetime.datetime.utcnow() - datetime.timedelta(days=settings.DAYS_OF_UNREAD)
    user = models.ForeignKey(User, related_name='subscriptions')
    feed = models.ForeignKey(Feed, related_name='subscribers')
    active = models.BooleanField(default=False)
    last_read_date = models.DateTimeField(default=UNREAD_CUTOFF)
    mark_read_date = models.DateTimeField(default=UNREAD_CUTOFF)
    unread_count_neutral = models.IntegerField(default=0)
    unread_count_positive = models.IntegerField(default=0)
    unread_count_negative = models.IntegerField(default=0)
    unread_count_updated = models.DateTimeField(default=datetime.datetime.now)
    needs_unread_recalc = models.BooleanField(default=False)
    feed_opens = models.IntegerField(default=0)
    is_trained = models.BooleanField(default=False)

    def __unicode__(self):
        return '[' + self.feed.feed_title + '] '
        
    def mark_feed_read(self):
        now = datetime.datetime.utcnow()
        if MStory.objects(story_feed_id=self.feed.pk).first():
            latest_story_date = MStory.objects(story_feed_id=self.feed.pk).order_by('-story_date').only('story_date')[0]['story_date']\
                                + datetime.timedelta(minutes=1)
        else:
            latest_story_date = now
        self.last_read_date = latest_story_date
        self.mark_read_date = latest_story_date
        self.unread_count_negative = 0
        self.unread_count_positive = 0
        self.unread_count_neutral = 0
        self.unread_count_updated = latest_story_date
        self.needs_unread_recalc = False
        self.save()
    
    def calculate_feed_scores(self, silent=False, stories_db=None):
        UNREAD_CUTOFF = datetime.datetime.utcnow() - datetime.timedelta(days=settings.DAYS_OF_UNREAD)
        now = datetime.datetime.utcnow()

        if self.user.profile.last_seen_on < UNREAD_CUTOFF:
            # if not silent:
            #     logging.info(' ---> [%s] SKIPPING Computing scores: %s (1 week+)' % (self.user, self.feed))
            return
        
        if not self.feed.fetched_once:
            if not silent:
                logging.info(' ---> [%s] NOT Computing scores: %s' % (self.user, self.feed))
            self.needs_unread_recalc = False
            self.save()
            return

        if not silent:
            logging.info(' ---> [%s] Computing scores: %s' % (self.user, self.feed))
        feed_scores = dict(negative=0, neutral=0, positive=0)
        
        # Two weeks in age. If mark_read_date is older, mark old stories as read.
        date_delta = UNREAD_CUTOFF
        if date_delta < self.mark_read_date:
            date_delta = self.mark_read_date
        else:
            self.mark_read_date = date_delta
            
        read_stories = MUserStory.objects(user_id=self.user.pk,
                                          feed_id=self.feed.pk,
                                          read_date__gte=self.mark_read_date)
        # if not silent:
        #     logging.info(' ---> [%s]    Read stories: %s' % (self.user, datetime.datetime.now() - now))
        read_stories_ids = []
        for us in read_stories:
            if hasattr(us.story, 'story_guid') and isinstance(us.story.story_guid, unicode):
                read_stories_ids.append(us.story.story_guid)
            elif hasattr(us.story, 'id') and isinstance(us.story.id, unicode):
                read_stories_ids.append(us.story.id) # TODO: Remove me after migration from story.id->guid
        stories_db = stories_db or MStory.objects(story_feed_id=self.feed.pk,
                                                  story_date__gte=date_delta)
        # if not silent:
        #     logging.info(' ---> [%s]    MStory: %s' % (self.user, datetime.datetime.now() - now))
        unread_stories_db = []
        for story in stories_db:
            if story.story_date < date_delta:
                continue
            if hasattr(story, 'story_guid') and story.story_guid not in read_stories_ids:
                unread_stories_db.append(story)
            elif isinstance(story.id, unicode) and story.id not in read_stories_ids:
                unread_stories_db.append(story)
        stories = self.feed.format_stories(unread_stories_db)
        # if not silent:
        #     logging.info(' ---> [%s]    Format stories: %s' % (self.user, datetime.datetime.now() - now))
        
        classifier_feeds = MClassifierFeed.objects(user_id=self.user.pk, feed_id=self.feed.pk)
        classifier_authors = MClassifierAuthor.objects(user_id=self.user.pk, feed_id=self.feed.pk)
        classifier_titles = MClassifierTitle.objects(user_id=self.user.pk, feed_id=self.feed.pk)
        classifier_tags = MClassifierTag.objects(user_id=self.user.pk, feed_id=self.feed.pk)
        
        # if not silent:
        #     logging.info(' ---> [%s]    Classifiers: %s (%s)' % (self.user, datetime.datetime.now() - now, classifier_feeds.count() + classifier_authors.count() + classifier_tags.count() + classifier_titles.count()))
            
        scores = {
            'feed': apply_classifier_feeds(classifier_feeds, self.feed),
        }
        
        for story in stories:
            classifier_authors.rewind()
            classifier_tags.rewind()
            classifier_titles.rewind()
            scores.update({
                'author': apply_classifier_authors(classifier_authors, story),
                'tags': apply_classifier_tags(classifier_tags, story),
                'title': apply_classifier_titles(classifier_titles, story),
            })
            
            max_score = max(scores['author'], scores['tags'], scores['title'])
            min_score = min(scores['author'], scores['tags'], scores['title'])
            if max_score > 0:
                feed_scores['positive'] += 1
            elif min_score < 0:
                feed_scores['negative'] += 1
            else:
                if scores['feed'] > 0:
                    feed_scores['positive'] += 1
                elif scores['feed'] < 0:
                    feed_scores['negative'] += 1
                else:
                    feed_scores['neutral'] += 1
                
        
        # if not silent:
        #     logging.info(' ---> [%s]    End classifiers: %s' % (self.user, datetime.datetime.now() - now))
            
        self.unread_count_positive = feed_scores['positive']
        self.unread_count_neutral = feed_scores['neutral']
        self.unread_count_negative = feed_scores['negative']
        self.needs_unread_recalc = False
        
        self.save()
        
        if (self.unread_count_positive == 0 and 
            self.unread_count_neutral == 0):
            self.mark_feed_read()
        
        cache.delete('usersub:%s' % self.user.id)
        
        return
        
    class Meta:
        unique_together = ("user", "feed")
        
        
class UserStory(models.Model):
    """
    Stories read by the user. These are deleted as the mark_read_date for the
    UserSubscription passes the UserStory date.
    """
    user = models.ForeignKey(User)
    feed = models.ForeignKey(Feed)
    story = models.ForeignKey(Story)
    read_date = models.DateTimeField(auto_now=True)
    opinion = models.IntegerField(default=0)
    
    def __unicode__(self):
        return ('[' + self.feed.feed_title + '] '
                + self.story.story_title)
        
    class Meta:
        verbose_name_plural = "user stories"
        verbose_name = "user story"
        unique_together = ("user", "feed", "story")
        
        
class MUserStory(mongo.Document):
    """
    Stories read by the user. These are deleted as the mark_read_date for the
    UserSubscription passes the UserStory date.
    """
    user_id = mongo.IntField()
    feed_id = mongo.IntField()
    read_date = mongo.DateTimeField()
    story = mongo.ReferenceField(MStory, unique_with=('user_id', 'feed_id'))
    
    meta = {
        'collection': 'userstories',
        'indexes': ['feed_id', ('user_id', 'feed_id')],
        'allow_inheritance': False,
    }
    
    @classmethod
    def delete_old_stories(cls, feed_id):
        UNREAD_CUTOFF = datetime.datetime.utcnow() - datetime.timedelta(days=settings.DAYS_OF_UNREAD)
        MUserStory.objects(feed_id=feed_id, read_date__lte=UNREAD_CUTOFF).delete()
    
        
class UserSubscriptionFolders(models.Model):
    """
    A JSON list of folders and feeds for while a user has subscribed. The list
    is a recursive descent of feeds and folders in folders. Used to layout
    the feeds and folders in the Reader's feed navigation pane.
    """
    user = models.ForeignKey(User)
    folders = models.TextField(default="[]")
    
    def __unicode__(self):
        return "[%s]: %s" % (self.user, len(self.folders),)
        
    class Meta:
        verbose_name_plural = "folders"
        verbose_name = "folder"
        
    def delete_feed(self, feed_id, in_folder):
        def _find_feed_in_folders(old_folders, folder_name='', multiples_found=False, deleted=False):
            new_folders = []
            for k, folder in enumerate(old_folders):
                if isinstance(folder, int):
                    if (folder == feed_id and (
                        (folder_name != in_folder) or
                        (folder_name == in_folder and deleted))):
                        multiples_found = True
                        logging.info(" ---> [%s] Deleting feed, and a multiple has been found in '%s'" % (self.user, folder_name))
                    if folder == feed_id and folder_name == in_folder and not deleted:
                        logging.info(" ---> [%s] Delete feed: %s'th item: %s folders/feeds" % (
                            self.user, k, len(old_folders)
                        ))
                        deleted = True
                    else:
                        new_folders.append(folder)
                elif isinstance(folder, dict):
                    for f_k, f_v in folder.items():
                        nf, multiples_found, deleted = _find_feed_in_folders(f_v, f_k, multiples_found, deleted)
                        new_folders.append({f_k: nf})
    
            return new_folders, multiples_found, deleted
        
        user_sub_folders = json.decode(self.folders)
        user_sub_folders, multiples_found, deleted = _find_feed_in_folders(user_sub_folders)
        self.folders = json.encode(user_sub_folders)
        self.save()

        if not multiples_found and deleted:
            user_sub = UserSubscription.objects.get(user=self.user, feed=feed_id)
            user_sub.delete()
            MUserStory.objects(user_id=self.user.pk, feed_id=feed_id).delete()

    def delete_folder(self, folder_to_delete, in_folder, feed_ids_in_folder):
        def _find_folder_in_folders(old_folders, folder_name, feeds_to_delete):
            new_folders = []
            for k, folder in enumerate(old_folders):
                if isinstance(folder, int):
                    new_folders.append(folder)
                    if folder in feeds_to_delete:
                        feeds_to_delete.remove(folder)
                elif isinstance(folder, dict):
                    for f_k, f_v in folder.items():
                        if f_k == folder_to_delete and folder_name == in_folder:
                            logging.info(" ---> [%s] Deleting folder '%s' in '%s': %s" % (self.user, f_k, folder_name, folder))
                        else:
                            nf, feeds_to_delete = _find_folder_in_folders(f_v, f_k, feeds_to_delete)
                            new_folders.append({f_k: nf})
    
            return new_folders, feeds_to_delete
            
        user_sub_folders = json.decode(self.folders)
        user_sub_folders, feeds_to_delete = _find_folder_in_folders(user_sub_folders, '', feed_ids_in_folder)
        self.folders = json.encode(user_sub_folders)
        self.save()
        
        UserSubscription.objects.filter(user=self.user, feed__in=feeds_to_delete).delete()

class Feature(models.Model):
    """
    Simple blog-like feature board shown to all users on the home page.
    """
    description = models.TextField(default="")
    date = models.DateTimeField(default=datetime.datetime.now)
    
    def __unicode__(self):
        return "[%s] %s" % (self.date, self.description[:50])
    
    class Meta:
        ordering = ["-date"]