from django.core.management.base import NoArgsCommand
from django.db import connection
from django.db.models import Q, F
from forum.models import *
from forum import const
from django.core.mail import EmailMessage
from django.utils.translation import ugettext as _
from django.utils.translation import ungettext
import datetime
from django.conf import settings
import logging
from forum.utils.odict import OrderedDict
from django.contrib.contenttypes.models import ContentType
from forum import const
def extend_question_list(src, dst, limit=False):
"""src is a query set with questions
or None
dst - is an ordered dictionary
"""
if limit and len(dst.keys()) >= const.MAX_ALERTS_PER_EMAIL:
return
if src is None:#is not QuerySet
return #will not do anything if subscription of this type is not used
cutoff_time = src.cutoff_time
for q in src:
if q in dst:
#the latest cutoff time wins for a given question
#if the question falls into several subscription groups
if cutoff_time > dst[q]['cutoff_time']:
dst[q]['cutoff_time'] = cutoff_time
else:
#initialise a questions metadata dictionary to use for email reporting
dst[q] = {'cutoff_time':cutoff_time}
class Command(NoArgsCommand):
def handle_noargs(self,**options):
try:
try:
self.send_email_alerts()
except Exception, e:
print e
finally:
connection.close()
def get_updated_questions_for_user(self,user):
#these are placeholders for separate query sets per question group
#there are four groups - one for each EmailFeedSetting.feed_type
#and each group has subtypes A and B
#that's because of the strange thing commented below
#see note on Q and F objects marked with todo tag
q_sel_A = None
q_sel_B = None
q_ask_A = None
q_ask_B = None
q_ans_A = None
q_ans_B = None
q_all_A = None
q_all_B = None
now = datetime.datetime.now()
#Q_set1 - base questionquery set for this user
Q_set1 = Question.objects.exclude(
last_activity_by=user
).exclude(
last_activity_at__lt=user.date_joined#exclude old stuff
).exclude(
deleted=True
).exclude(
closed=True
).order_by('-last_activity_at')
#todo: for some reason filter on did not work as expected ~Q(viewed__who=user) |
# Q(viewed__who=user,viewed__when__lt=F('last_activity_at'))
#returns way more questions than you might think it should
#so because of that I've created separate query sets Q_set2 and Q_set3
#plus two separate queries run faster!
#questions that are not seen by the user
Q_set2 = Q_set1.filter(~Q(viewed__who=user))
#questions seen before the last modification
Q_set3 = Q_set1.filter(Q(viewed__who=user,viewed__when__lt=F('last_activity_at')))
#todo may shortcirquit here is len(user_feeds) == 0
user_feeds = EmailFeedSetting.objects.filter(subscriber=user).exclude(frequency='n')
if len(user_feeds) == 0:
return {};#short cirquit
for feed in user_feeds:
#each group of updates has it's own cutoff time
#to be saved as a new parameter for each query set
#won't send email for a given question if it has been done
#after the cutoff_time
cutoff_time = now - EmailFeedSetting.DELTA_TABLE[feed.frequency]
if feed.reported_at == None or feed.reported_at <= cutoff_time:
Q_set_A = Q_set2#.exclude(last_activity_at__gt=cutoff_time)#report these excluded later
Q_set_B = Q_set3#.exclude(last_activity_at__gt=cutoff_time)
feed.reported_at = now
feed.save()#may not actually report anything, depending on filters below
if feed.feed_type == 'q_sel':
q_sel_A = Q_set_A.filter(followed_by=user)
q_sel_A.cutoff_time = cutoff_time #store cutoff time per query set
q_sel_B = Q_set_B.filter(followed_by=user)
q_sel_B.cutoff_time = cutoff_time #store cutoff time per query set
elif feed.feed_type == 'q_ask':
q_ask_A = Q_set_A.filter(author=user)
q_ask_A.cutoff_time = cutoff_time
q_ask_B = Q_set_B.filter(author=user)
q_ask_B.cutoff_time = cutoff_time
elif feed.feed_type == 'q_ans':
q_ans_A = Q_set_A.filter(answers__author=user)[:const.MAX_ALERTS_PER_EMAIL]
q_ans_A.cutoff_time = cutoff_time
q_ans_B = Q_set_B.filter(answers__author=user)[:const.MAX_ALERTS_PER_EMAIL]
q_ans_B.cutoff_time = cutoff_time
elif feed.feed_type == 'q_all':
if user.tag_filter_setting == 'ignored':
ignored_tags = Tag.objects.filter(user_selections__reason='bad', \
user_selections__user=user)
q_all_A = Q_set_A.exclude( tags__in=ignored_tags )[:const.MAX_ALERTS_PER_EMAIL]
q_all_B = Q_set_B.exclude( tags__in=ignored_tags )[:const.MAX_ALERTS_PER_EMAIL]
else:
selected_tags = Tag.objects.filter(user_selections__reason='good', \
user_selections__user=user)
q_all_A = Q_set_A.filter( tags__in=selected_tags )
q_all_B = Q_set_B.filter( tags__in=selected_tags )
q_all_A.cutoff_time = cutoff_time
q_all_B.cutoff_time = cutoff_time
#build list in this order
q_list = OrderedDict()
extend_question_list(q_sel_A, q_list)
extend_question_list(q_sel_B, q_list)
if user.tag_filter_setting == 'interesting':
extend_question_list(q_all_A, q_list)
extend_question_list(q_all_B, q_list)
extend_question_list(q_ask_A, q_list, limit=True)
extend_question_list(q_ask_B, q_list, limit=True)
extend_question_list(q_ans_A, q_list, limit=True)
extend_question_list(q_ans_B, q_list, limit=True)
if user.tag_filter_setting == 'ignored':
extend_question_list(q_all_A, q_list, limit=True)
extend_question_list(q_all_B, q_list, limit=True)
ctype = ContentType.objects.get_for_model(Question)
EMAIL_UPDATE_ACTIVITY = const.TYPE_ACTIVITY_QUESTION_EMAIL_UPDATE_SENT
for q, meta_data in q_list.items():
#this loop edits meta_data for each question
#so that user will receive counts on new edits new answers, etc
#maybe not so important actually??
#keeps email activity per question per user
try:
update_info = Activity.objects.get(
user=user,
content_type=ctype,
object_id=q.id,
activity_type=EMAIL_UPDATE_ACTIVITY
)
emailed_at = update_info.active_at
except Activity.DoesNotExist:
update_info = Activity(user=user, content_object=q, activity_type=EMAIL_UPDATE_ACTIVITY)
emailed_at = datetime.datetime(1970,1,1)#long time ago
except Activity.MultipleObjectsReturned:
raise Exception('server error - multiple question email activities found per user-question pair')
cutoff_time = meta_data['cutoff_time']#cutoff time for the question
#wait some more time before emailing about this question
if emailed_at > cutoff_time:
#here we are maybe losing opportunity to record the finding
#of yet unseen version of a question
meta_data['skip'] = True
continue
#collect info on all sorts of news that happened after
#the most recent emailing to the user about this question
q_rev = QuestionRevision.objects.filter(question=q,\
revised_at__gt=emailed_at)
q_rev = q_rev.exclude(author=user)
#now update all sorts of metadata per question
meta_data['q_rev'] = len(q_rev)
if len(q_rev) > 0 and q.added_at == q_rev[0].revised_at:
meta_data['q_rev'] = 0
meta_data['new_q'] = True
else:
meta_data['new_q'] = False
new_ans = Answer.objects.filter(question=q,\
added_at__gt=emailed_at)
new_ans = new_ans.exclude(author=user)
meta_data['new_ans'] = len(new_ans)
ans_rev = AnswerRevision.objects.filter(answer__question=q,\
revised_at__gt=emailed_at)
ans_rev = ans_rev.exclude(author=user)
meta_data['ans_rev'] = len(ans_rev)
if len(q_rev) + len(new_ans) + len(ans_rev) == 0:
meta_data['skip'] = True
else:
meta_data['skip'] = False
update_info.active_at = now
update_info.save() #save question email update activity
#q_list is actually a ordered dictionary
#print 'user %s gets %d' % (user.username, len(q_list.keys()))
#todo: sort question list by update time
return q_list
def __action_count(self,string,number,output):
if number > 0:
output.append(_(string) % {'num':number})
def send_email_alerts(self):
#does not change the database, only sends the email
#todo: move this to template
for user in User.objects.all():
#todo: q_list is a dictionary, not a list
q_list = self.get_updated_questions_for_user(user)
if len(q_list.keys()) == 0:
continue
num_q = 0
num_moot = 0
for meta_data in q_list.values():
if meta_data['skip']:
num_moot = True
else:
num_q += 1
if num_q > 0:
url_prefix = settings.APP_URL
subject = _('email update message subject')
print 'have %d updated questions for %s' % (num_q, user.username)
text = ungettext('%(name)s, this is an update message header for %(num)d question',
'%(name)s, this is an update message header for %(num)d questions',num_q) \
% {'num':num_q, 'name':user.username}
text += ''
items_added = 0
items_unreported = 0
for q, meta_data in q_list.items():
act_list = []
if meta_data['skip']:
continue
if items_added >= const.MAX_ALERTS_PER_EMAIL:
items_unreported = num_q - items_added #may be inaccurate actually, but it's ok
else:
items_added += 1
if meta_data['new_q']:
act_list.append(_('new question'))
self.__action_count('%(num)d rev', meta_data['q_rev'],act_list)
self.__action_count('%(num)d ans', meta_data['new_ans'],act_list)
self.__action_count('%(num)d ans rev',meta_data['ans_rev'],act_list)
act_token = ', '.join(act_list)
text += '- %s (%s)
' \
% (url_prefix + q.get_absolute_url(), q.title, act_token)
text += '
'
text += ''
#if len(q_list.keys()) >= const.MAX_ALERTS_PER_EMAIL:
# text += _('There may be more questions updated since '
# 'you have logged in last time as this list is '
# 'abridged for your convinience. Please visit '
# 'the forum and see what\'s new!
'
# )
text += _(
'Please visit the forum and see what\'s new! '
'Could you spread the word about it - '
'can somebody you know help answering those questions or '
'benefit from posting one?'
)
feeds = EmailFeedSetting.objects.filter(
subscriber=user,
)
feed_freq = [feed.frequency for feed in feeds]
text += ''
if 'd' in feed_freq:
text += _('Your most frequent subscription setting is \'daily\' '
'on selected questions. If you are receiving more than one '
'email per day'
'please tell about this issue to the forum administrator.'
)
elif 'w' in feed_freq:
text += _('Your most frequent subscription setting is \'weekly\' '
'if you are receiving this email more than once a week '
'please report this issue to the forum administrator.'
)
text += ' '
text += _(
'There is a chance that you may be receiving links seen '
'before - due to a technicality that will eventually go away. '
)
# text += ''
#if num_moot > 0:
# text += ''
# text += ungettext('There is also one question which was recently '\
# +'updated but you might not have seen its latest version.',
# 'There are also %(num)d more questions which were recently updated '\
# +'but you might not have seen their latest version.',num_moot) \
# % {'num':num_moot,}
# text += _('Perhaps you could look up previously sent forum reminders in your mailbox.')
# text += ''
link = url_prefix + user.get_profile_url() + '?sort=email_subscriptions'
text += _('go to %(link)s to change frequency of email updates or %(email)s administrator') \
% {'link':link, 'email':settings.ADMINS[0][1]}
msg = EmailMessage(subject, text, settings.DEFAULT_FROM_EMAIL, [user.email])
msg.content_subtype = 'html'
msg.send()
#uncomment lines below to get copies of emails sent to others
#todo: maybe some debug setting would be appropriate here
#msg2 = EmailMessage(subject, text, settings.DEFAULT_FROM_EMAIL, ['your@email.com'])
#msg2.content_subtype = 'html'
#msg2.send()