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.utils.translation import ugettext as _

from astakos.im.models import AstakosUser

from astakos.im.forms import LocalUserCreationForm, ShibbolethUserCreationForm

from astakos.im.util import get_invitation

from astakos.im.functions import (send_verification, send_activation,

                                  send_account_creation_notification,

                                  send_group_creation_notification, activate)

from astakos.im.settings import INVITATIONS_ENABLED, MODERATION_ENABLED, SITENAME, RE_USER_EMAIL_PATTERNS

import logging

import re

logger = logging.getLogger(__name__)

def get_backend(request):

    """

    Returns an instance of an activation backend,

    according to the INVITATIONS_ENABLED setting

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

    returns ``astakos.im.activation_backends.SimpleBackend``).

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

    is raised.

    """

    module = 'astakos.im.activation_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 activation backend %s: "%s"' % (module, e))

    try:

        backend_class = getattr(mod, backend_class_name)

    except AttributeError:

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

    return backend_class(request)

class ActivationBackend(object):

    def __init__(self, request):

        self.request = request

    def _is_preaccepted(self, user):

        # return True if user email matches specific patterns

        for pattern in RE_USER_EMAIL_PATTERNS:

            if re.match(pattern, user.email):

                return True

        return False

    def get_signup_form(self, provider='local', instance=None):

        """

        Returns a form instance of the relevant class

        """

        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, instance=instance, request=request)

    def handle_activation(self, user,

                          activation_template_name='im/activation_email.txt',

                          greeting_template_name='im/welcome_email.txt',

                          admin_email_template_name='im/account_notification.txt',

                          switch_accounts_email_template_name='im/switch_accounts_email.txt'):

        """

        If the user is already active returns immediately.

        If the user is not active and there is another account associated with

        the specific email, it sends an informative email to the user whether

        wants to switch to this account.

        If the user is preaccepted and the email is verified, the account is

        activated automatically. Otherwise, if the email is not verified,

        it sends a verification email to the user.

        If the user is not preaccepted, it sends an email to the administrators

        and informs the user that the account is pending activation.

        """

        try:

            if user.is_active:

                return RegistationCompleted()

            if user.conflicting_email():

                send_verification(user, switch_accounts_email_template_name)

                return SwitchAccountsVerificationSent(user.email)

            if self._is_preaccepted(user):

                if user.email_verified:

                    activate(user, greeting_template_name)

                    return RegistationCompleted()

                else:

                    send_activation(user, activation_template_name)

                    return VerificationSent()

            else:

                send_account_creation_notification(

                    template_name=admin_email_template_name,

                    dictionary={'user': user, 'group_creation': True}

                )

                return NotificationSent()

        except BaseException, e:

            logger.exception(e)

            raise e

class InvitationsBackend(ActivationBackend):

    """

    A activation 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 get_signup_form(self, provider='local', instance=None):

        """

        Returns a form instance of the relevant class

        raises Invitation.DoesNotExist and ValueError if invitation is consumed

        or invitation username is reserved.

        """

        self.invitation = get_invitation(self.request)

        invitation = self.invitation

        initial_data = self.get_signup_initial_data(provider)

        prefix = 'Invited' if invitation else ''

        main = provider.capitalize()

        suffix = 'UserCreationForm'

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

        return globals()[formclass](initial_data, instance=instance, request=self.request)

    def get_signup_initial_data(self, provider):

        """

        Returns the necassary activation 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,

                                'provider': provider}

        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.

        """

        if super(InvitationsBackend, self)._is_preaccepted(user):

            return True

        invitation = self.invitation

        if not invitation:

            return False

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

            invitation.consume()

            return True

        return False

class SimpleBackend(ActivationBackend):

    """

    A activation 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 _is_preaccepted(self, user):

        if super(SimpleBackend, self)._is_preaccepted(user):

            return True

        if MODERATION_ENABLED:

            return False

        return True

class ActivationResult(object):

    def __init__(self, message):

        self.message = message

class VerificationSent(ActivationResult):

    def __init__(self):

        message = _('Verification sent.')

        super(VerificationSent, self).__init__(message)

class SwitchAccountsVerificationSent(ActivationResult):

    def __init__(self, email):

        message = _('This email is already associated with another \

                    local account. To change this account to a shibboleth \

                    one follow the link in the verification email sent \

                    to %s. Otherwise just ignore it.' % email)

        super(SwitchAccountsVerificationSent, self).__init__(message)

class NotificationSent(ActivationResult):

    def __init__(self):

        message = _('Your request for an account was successfully received and is now pending \

                    approval. You will be notified by email in the next few days. Thanks for \

                    your interest in ~okeanos! The GRNET team.')

        super(NotificationSent, self).__init__(message)

class RegistationCompleted(ActivationResult):

    def __init__(self):

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

        super(RegistationCompleted, self).__init__(message)