Synnefo

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

#

# Redistribution and use in source and binary forms, with or

# without modification, are permitted provided that the following

# conditions are met:

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#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

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#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

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# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

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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.contrib.sites.models import Site

from django.contrib import messages

from django.core.urlresolvers import reverse

from django.utils.translation import ugettext as _

from django.db import transaction

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.functions import send_verification, send_admin_notification, activate, SendMailError

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

import socket

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, attr))

    return backend_class(request)

class ActivationBackend(object):

    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 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, instance=instance, request=request)

    def handle_activation(self, user, \

                          verification_template_name='im/activation_email.txt', \

                          greeting_template_name='im/welcome_email.txt', \

                          admin_email_template_name='im/admin_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_verification(user, verification_template_name)

                    return VerificationSent()

            else:

                send_admin_notification(user, admin_email_template_name)

                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 __init__(self, request):

        self.request = request

        super(InvitationsBackend, self).__init__()

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

        """

        Returns the form 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 __init__(self, request):

        self.request = request

        super(SimpleBackend, self).__init__()

    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)