#!/usr/bin/python2.5

#

# Copyright 2008 the Melange authors.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#   http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""Helper functions for sending out notifications.

"""

__authors__ = [

  '"Lennard de Rijk" <ljvderijk@gmail.com>',

  ]

import os

import time

from google.appengine.api import users

from django.template import loader

from django.utils.encoding import force_unicode

from django.utils.translation import ugettext

# We cannot import soc.logic.models notification nor user here

# due to cyclic imports

from soc.logic import dicts

from soc.logic import mail_dispatcher

from soc.views.helper import redirects

import soc.views.models as model_view

import soc.logic.models as model_logic

DEF_NEW_NOTIFICATION_MSG = ugettext(

  "You have received a new Notification.")

DEF_INVITATION_MSG_FMT = ugettext(

    "Invitation to become a %(role_verbose)s for %(group)s.")

DEF_NEW_GROUP_MSG_FMT = ugettext(

    "Your %(application_type)s for %(group_name)s has been accepted.")

DEF_WELCOME_MSG_FMT = ugettext("Welcome to Melange %(name)s,")

DEF_GROUP_INVITE_NOTIFICATION_TEMPLATE = 'soc/notification/messages/invitation.html'

DEF_NEW_GROUP_TEMPLATE = 'soc/group/messages/accepted.html'

def sendInviteNotification(entity):

  """Sends out an invite notification to the user the request is for.

  Args:

    entity : A request containing the information needed to create the message

  """

  # get the user the request is for

  properties = {'link_id': entity.link_id }

  to_user = model_logic.user.logic.getForFields(properties, unique=True)

  invitation_url = "http://%(host)s%(index)s" % {

      'host' : os.environ['HTTP_HOST'],

      'index': redirects.getInviteProcessRedirect(entity, None),

      }

  message_properties = {

      'role_verbose' : entity.role_verbose,

      'group': entity.scope.name,

      'invitation_url': invitation_url,

      }

  subject = DEF_INVITATION_MSG_FMT % {

      'role_verbose' : entity.role_verbose,

      'group' : entity.scope.name

      }

  template = DEF_GROUP_INVITE_NOTIFICATION_TEMPLATE

  sendNotification(to_user, message_properties, subject, template)

def sendNewGroupNotification(entity, params):

  """Sends out an invite notification to the applicant of the group.

  Args:

    entity : An accepted group application

  """

  to_user = entity.applicant

  url = "http://%(host)s%(redirect)s" % {

      'redirect': redirects.getApplicantRedirect(entity, 

      {'url_name': params['group_url_name']}),

      'host': os.environ['HTTP_HOST'],

      }

  message_properties = {

      'group_name': entity.name,

      'url': url,

      }

  subject = DEF_NEW_GROUP_MSG_FMT % {

      'application_type': params['name'],

      'group_name': entity.name,

      }

  template = DEF_NEW_GROUP_TEMPLATE

  sendNotification(to_user, message_properties, subject, template)

def sendNotification(to_user, message_properties, subject, template):

  """Sends out an notification to the specified user.

  Args:

    to_user : user to which the notification will be send

    message_properties : email message properties

    subject : subject of notification email

    template : template used for generating notification

  """

  from_user = model_logic.user.logic.getForCurrentAccount()

  new_message_properties = {

      'sender_name': from_user.name,

      'to_name': to_user.name,

      }

  message_properties = dicts.merge(message_properties, new_message_properties)

  message = loader.render_to_string(template, dictionary=message_properties)

  fields = {

      'from_user' : from_user,

      'subject': subject,

      'message' : message,

      'scope' : to_user,

      'link_id' :'t%i' % (time.time()),

      'scope_path' : to_user.link_id

  }

  key_fields = model_logic.notification.logic.getKeyFieldsFromFields(fields)

  # create and put a new notification in the datastore

  model_logic.notification.logic.updateOrCreateFromFields(fields, key_fields)

def sendNewNotificationMessage(notification_entity):

  """Sends an email to a user about a new notification.

    Args:

      notification_entity: Notification about which the message should be sent

  """

  # get user logic

  user_logic = model_logic.user

  # get the current user

  current_user_entity = user_logic.logic.getForCurrentAccount()

  # create the url to show this notification

  notification_url = "http://%(host)s%(index)s" % {

      'host' : os.environ['HTTP_HOST'],

      'index': redirects.getPublicRedirect(notification_entity,

          model_view.notification.view.getParams())}

  # TODO(Lennard): Change the sender to the no-reply address

  # create the message contents

  messageProperties = {

      'to_name': notification_entity.scope.name,

      'sender_name': current_user_entity.name,

      'to': notification_entity.scope.account.email(),

      'sender': current_user_entity.account.email(),

      'subject': force_unicode(DEF_NEW_NOTIFICATION_MSG),

      'notification' : notification_entity,

      'notification_url' : notification_url

      }

  # send out the message using the default new notification template

  mail_dispatcher.sendMailFromTemplate('soc/mail/new_notification.html',

                                       messageProperties)

def sendWelcomeMessage(user_entity):

  """Sends out a welcome message to a user.

    Args:

      user_entity: User entity which the message should be send to

  """

  # get user logic

  user_logic = model_logic.user

  # get the current user

  current_user_entity = user_logic.logic.getForCurrentAccount()

  # TODO(Lennard): change the message sender to some sort of no-reply adress

  # that is probably a setting in sitesettings. (adress must be a developer).

  # This is due to a GAE limitation that allows only devs or the current user

  # to send an email. Currently this results in a user receiving the same

  # email twice.

  # create the message contents

  messageProperties = {

      'to_name': user_entity.name,

      'sender_name': current_user_entity.name,

      'to': user_entity.account.email(),

      'sender': current_user_entity.account.email(),

      'subject': DEF_WELCOME_MSG_FMT % {

          'name': user_entity.name

          }

      }

  # send out the message using the default welcome template

  mail_dispatcher.sendMailFromTemplate('soc/mail/welcome.html',

                                       messageProperties)