from cm.models import Activity, Text, Notification, Comment, ApplicationConfiguration

from datetime import datetime, timedelta

from django.contrib.auth.models import User

from django.db.models import Q, signals

from django.utils.translation import ugettext as _

from django.template.loader import render_to_string

from time import mktime

from django.conf import settings

from cm.utils.mail import send_mail

import django.dispatch

import logging

class FakeRequest(object):

    def __init__(self, user):

        self.user = user

def notify(sender, **kwargs):

    from cm.security import get_viewable_comments, has_perm

    allready_notified = set() # avoid sending multiple notifications to same user

    activity = kwargs['instance']

    if activity.type in Activity.VIEWABLE_ACTIVITIES.get('view_users'): # user activity: only viewed by managers

        notifications = Notification.objects.filter(text=None, active=True).exclude(type='own')

        for notification in notifications:

            if notification.user:

                from cm.security import user_has_perm # import here!

                if user_has_perm(notification.user, 'can_manage_workspace'):

                    send_notification(activity, notification)

                    allready_notified.add(notification.user)

    elif activity.type in Activity.VIEWABLE_ACTIVITIES.get('view_comments'):

        notifications = Notification.objects.filter(Q(text=activity.text) | Q(text=None), active=True)

        for notification in notifications:            

            viewable = get_viewable_comments(FakeRequest(notification.user),

                                             Comment.objects.filter(id__in = [activity.comment.id]),

                                             text=activity.text)

            if viewable and \

                ((notification.type == 'own' and activity.comment.user != notification.user and activity.comment.top_comment().user == notification.user) or

                 (notification.type != 'own')):

                if not notification.user in allready_notified:

                    send_notification(activity, notification)

                    allready_notified.add(notification.user)            

    elif activity.type in Activity.VIEWABLE_ACTIVITIES.get('view_texts'):

        notifications = Notification.objects.filter(Q(text=activity.text) | Q(text=None), active=True).exclude(type='own')

        for notification in notifications:

            if notification.user:

                from cm.security import user_has_perm # import here!

                if user_has_perm(notification.user, 'can_view_text', text=activity.text) and not notification.user in allready_notified:

                    send_notification(activity, notification)

                    allready_notified.add(notification.user)

            else:

                if has_perm(None, 'can_view_text', text=activity.text) and not notification.email in allready_notified:

                    send_notification(activity, notification)

                    allready_notified.add(notification.email)                

signals.post_save.connect(notify, sender=Activity)

def send_notification(activity, notification):

    email = notification.user.email if notification.user else notification.email

    if email:

      subject = _('Notification:') + " " + activity.printable_data(html=False, link=False)

      message = render_to_string('email/activity_notification.txt',

                                   { 

                                     'activity' : activity,

                                     'notification' : notification,

                                     'SITE_URL' : settings.SITE_URL,

                                     'CONF' : ApplicationConfiguration,

                                      })

      send_mail(subject, message, ApplicationConfiguration['email_from'], [email], fail_silently=True)

      #logging.debug(u"Notification sent [%s] => %s" %(activity,notification.user) if notification.user else u"sending (email) %s => %s" %(activity,notification.email))