Synnefo

# Copyright 2011 GRNET S.A. All rights reserved.

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from django.utils.importlib import import_module

from django.core.exceptions import ImproperlyConfigured

from django.core.mail import send_mail

from django.template.loader import render_to_string

from django.utils.translation import ugettext as _

from django.contrib.sites.models import Site

from django.contrib import messages

from django.db import transaction

from django.core.urlresolvers import reverse

from smtplib import SMTPException

from urllib import quote

from urlparse import urljoin

from astakos.im.models import AstakosUser, Invitation

from astakos.im.forms import *

from astakos.im.util import get_invitation

from astakos.im.settings import INVITATIONS_ENABLED, DEFAULT_CONTACT_EMAIL, DEFAULT_FROM_EMAIL, MODERATION_ENABLED, SITENAME, BASEURL

import socket

import logging

logger = logging.getLogger(__name__)

def get_backend(request):

    """

    Returns an instance of a registration backend,

    according to the INVITATIONS_ENABLED setting

    (if True returns ``astakos.im.backends.InvitationsBackend`` and if False

    returns ``astakos.im.backends.SimpleBackend``).

    If the backend cannot be located ``django.core.exceptions.ImproperlyConfigured``

    is raised.

    """

    module = 'astakos.im.backends'

    prefix = 'Invitations' if INVITATIONS_ENABLED else 'Simple'

    backend_class_name = '%sBackend' %prefix

    try:

        mod = import_module(module)

    except ImportError, e:

        raise ImproperlyConfigured('Error loading registration backend %s: "%s"' % (module, e))

    try:

        backend_class = getattr(mod, backend_class_name)

    except AttributeError:

        raise ImproperlyConfigured('Module "%s" does not define a registration backend named "%s"' % (module, attr))

    return backend_class(request)

class InvitationsBackend(object):

    """

    A registration backend which implements the following workflow: a user

    supplies the necessary registation information, if the request contains a valid

    inivation code the user is automatically activated otherwise an inactive user

    account is created and the user is going to receive an email as soon as an

    administrator activates his/her account.

    """

    def __init__(self, request):

        """

        raises Invitation.DoesNotExist and ValueError if invitation is consumed

        or invitation username is reserved.

        """

        self.request = request

        self.invitation = get_invitation(request)

    def get_signup_form(self, provider):

        """

        Returns the form class name 

        """

        invitation = self.invitation

        initial_data = self.get_signup_initial_data(provider)

        prefix = 'Invited' if invitation else ''

        main = provider.capitalize() if provider == 'local' else 'ThirdParty'

        suffix  = 'UserCreationForm'

        formclass = '%s%s%s' % (prefix, main, suffix)

        return globals()[formclass](initial_data, ip=self.request.META['REMOTE_ADDR'])

    def get_signup_initial_data(self, provider):

        """

        Returns the necassary registration form depending the user is invited or not

        Throws Invitation.DoesNotExist in case ``code`` is not valid.

        """

        request = self.request

        invitation = self.invitation

        initial_data = None

        if request.method == 'GET':

            if invitation:

                # create a tmp user with the invitation realname

                # to extract first and last name

                u = AstakosUser(realname = invitation.realname)

                initial_data = {'email':invitation.username,

                                'inviter':invitation.inviter.realname,

                                'first_name':u.first_name,

                                'last_name':u.last_name}

        else:

            if provider == request.POST.get('provider', ''):

                initial_data = request.POST

        return initial_data

    def _is_preaccepted(self, user):

        """

        If there is a valid, not-consumed invitation code for the specific user

        returns True else returns False.

        """

        invitation = self.invitation

        if not invitation:

            return False

        if invitation.username == user.email and not invitation.is_consumed:

            invitation.consume()

            return True

        return False

    @transaction.commit_manually

    def signup(self, form):

        """

        Initially creates an inactive user account. If the user is preaccepted

        (has a valid invitation code) the user is activated and if the request

        param ``next`` is present redirects to it.

        In any other case the method returns the action status and a message.

        The method uses commit_manually decorator in order to ensure the user

        will be created only if the procedure has been completed successfully.

        """

        user = None

        try:

            user = form.save()

            if self._is_preaccepted(user):

                user.is_active = True

                user.save()

                message = _('Registration completed. You can now login.')

            else:

                message = _('Registration completed. You will receive an email upon your account\'s activation.')

            status = messages.SUCCESS

        except Invitation.DoesNotExist, e:

            status = messages.ERROR

            message = _('Invalid invitation code')

        except socket.error, e:

            status = messages.ERROR

            message = _(e.strerror)

        # rollback in case of error

        if status == messages.ERROR:

            transaction.rollback()

        else:

            transaction.commit()

        return status, message, user

class SimpleBackend(object):

    """

    A registration backend which implements the following workflow: a user

    supplies the necessary registation information, an incative user account is

    created and receives an email in order to activate his/her account.

    """

    def __init__(self, request):

        self.request = request

    def get_signup_form(self, provider):

        """

        Returns the form class name

        """

        main = provider.capitalize() if provider == 'local' else 'ThirdParty'

        suffix  = 'UserCreationForm'

        formclass = '%s%s' % (main, suffix)

        request = self.request

        initial_data = None

        if request.method == 'POST':

            if provider == request.POST.get('provider', ''):

                initial_data = request.POST

        return globals()[formclass](initial_data, ip=self.request.META['REMOTE_ADDR'])

    @transaction.commit_manually

    def signup(self, form, email_template_name='im/activation_email.txt'):

        """

        Creates an inactive user account and sends a verification email.

        The method uses commit_manually decorator in order to ensure the user

        will be created only if the procedure has been completed successfully.

        ** Arguments **

        ``email_template_name``

            A custom template for the verification email body to use. This is

            optional; if not specified, this will default to

            ``im/activation_email.txt``.

        ** Templates **

            im/activation_email.txt or ``email_template_name`` keyword argument

        ** Settings **

        * DEFAULT_CONTACT_EMAIL: service support email

        * DEFAULT_FROM_EMAIL: from email

        """

        user = form.save()

        status = messages.SUCCESS

        if MODERATION_ENABLED:

            message = _('Registration completed. You will receive an email upon your account\'s activation.')

        else:

            try:

                _send_verification(self.request, user, email_template_name)

                message = _('Verification sent to %s' % user.email)

            except (SMTPException, socket.error) as e:

                status = messages.ERROR

                name = 'strerror'

                message = getattr(e, name) if hasattr(e, name) else e

        # rollback in case of error

        if status == messages.ERROR:

            transaction.rollback()

        else:

            transaction.commit()

        return status, message, user

def _send_verification(request, user, template_name):

    url = '%s?auth=%s&next=%s' % (urljoin(BASEURL, reverse('astakos.im.views.activate')),

                                    quote(user.auth_token),

                                    quote(BASEURL))

    message = render_to_string(template_name, {

            'user': user,

            'url': url,

            'baseurl': BASEURL,

            'site_name': SITENAME,

            'support': DEFAULT_CONTACT_EMAIL})

    sender = DEFAULT_FROM_EMAIL

    send_mail('%s account activation' % SITENAME, message, sender, [user.email])

    logger.info('Sent activation %s', user)