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 import models

from astakos.im import functions

from astakos.im import settings

from astakos.im import forms

import astakos.im.messages as astakos_messages

import datetime

import logging

import re

import json

logger = logging.getLogger(__name__)

def get_backend():

    """

    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 settings.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(settings.MODERATION_ENABLED)

class ActivationBackend(object):

    """

    ActivationBackend handles user verification/activation.

    Example usage::

    >>> # it is wise to not instantiate a backend class directly but use

    >>> # get_backend method instead.

    >>> backend = get_backend()

    >>> formCls = backend.get_signup_form(request.POST)

    >>> if form.is_valid():

    >>>     user = form.create_user()

    >>>     activation = backend.handle_registration(user)

    >>>     # activation.status is one of backend.Result.{*} activation result

    >>>     # types

    >>>

    >>>     # sending activation notifications is not done automatically

    >>>     # we need to call send_result_notifications

    >>>     backend.send_result_notifications(activation)

    >>>     return HttpResponse(activation.message)

    """

    verification_template_name = 'im/activation_email.txt'

    greeting_template_name = 'im/welcome_email.txt'

    pending_moderation_template_name = \

        'im/account_pending_moderation_notification.txt'

    activated_email_template_name = 'im/account_activated_notification.txt'

    class Result:

        # user created, email verification sent

        PENDING_VERIFICATION = 1

        # email verified

        PENDING_MODERATION = 2

        # user moderated

        ACCEPTED = 3

        # user rejected

        REJECTED = 4

        # inactive user activated

        ACTIVATED = 5

        # active user deactivated

        DEACTIVATED = 6

        # something went wrong

        ERROR = -1

    def __init__(self, moderation_enabled):

        self.moderation_enabled = moderation_enabled

    def _is_preaccepted(self, user):

        """

        Decide whether user should be automatically moderated. The method gets

        called only when self.moderation_enabled is set to True.

        The method returns False or a string identifier which later will be

        stored in user's accepted_policy field. This is helpfull for

        administrators to be aware of the reason a created user was

        automatically activated.

        """

        # check preaccepted mail patterns

        for pattern in settings.RE_USER_EMAIL_PATTERNS:

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

                return 'email'

        # provider automoderate policy is on

        if user.get_auth_provider().get_automoderate_policy:

            return 'auth_provider_%s' % user.get_auth_provider().module

        return False

    def get_signup_form(self, provider='local', initial_data=None, **kwargs):

        """

        Returns a form instance for the type of registration the user chosen.

        This can be either a LocalUserCreationForm for classic method signups

        or ThirdPartyUserCreationForm for users who chosen to signup using a

        federated login method.

        """

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

        suffix = 'UserCreationForm'

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

        kwargs['provider'] = provider

        return formclass(initial_data, **kwargs)

    def prepare_user(self, user, email_verified=None):

        """

        Initialization of a newly registered user. The method sets email

        verification code. If email_verified is set to True we automatically

        process user through the verification step.

        """

        logger.info("Initializing user registration %s", user.log_display)

        if not email_verified:

            email_verified = settings.SKIP_EMAIL_VERIFICATION

        user.renew_verification_code()

        user.save()

        if email_verified:

            logger.info("Auto verifying user email. %s",

                        user.log_display)

            return self.verify_user(user,

                                    user.verification_code)

        return ActivationResult(self.Result.PENDING_VERIFICATION)

    def verify_user(self, user, verification_code):

        """

        Process user verification using provided verification_code. This

        should take place in user activation view. If no moderation is enabled

        we automatically process user through activation process.

        """

        logger.info("Verifying user: %s", user.log_display)

        if user.email_verified:

            logger.warning("User email already verified: %s",

                           user.log_display)

            msg = astakos_messages.ACCOUNT_ALREADY_VERIFIED

            return ActivationResult(self.Result.ERROR, msg)

        if user.verification_code and \

                user.verification_code == verification_code:

            user.email_verified = True

            user.verified_at = datetime.datetime.now()

            # invalidate previous code

            user.renew_verification_code()

            user.save()

            logger.info("User email verified: %s", user.log_display)

        else:

            logger.error("User email verification failed "

                         "(invalid verification code): %s", user.log_display)

            msg = astakos_messages.VERIFICATION_FAILED

            return ActivationResult(self.Result.ERROR, msg)

        if not self.moderation_enabled:

            logger.warning("User preaccepted (%s): %s", 'auto_moderation',

                           user.log_display)

            return self.accept_user(user, policy='auto_moderation')

        preaccepted = self._is_preaccepted(user)

        if preaccepted:

            logger.warning("User preaccepted (%s): %s", preaccepted,

                           user.log_display)

            return self.accept_user(user, policy=preaccepted)

        if user.moderated:

            # set moderated to false because accept_user will return error

            # result otherwise.

            user.moderated = False

            return self.accept_user(user, policy='already_moderated')

        else:

            return ActivationResult(self.Result.PENDING_MODERATION)

    def accept_user(self, user, policy='manual'):

        logger.info("Moderating user: %s", user.log_display)

        if user.moderated and user.is_active:

            logger.warning("User already accepted, moderation"

                           " skipped: %s", user.log_display)

            msg = _(astakos_messages.ACCOUNT_ALREADY_MODERATED)

            return ActivationResult(self.Result.ERROR, msg)

        if not user.email_verified:

            logger.warning("Cannot accept unverified user: %s",

                           user.log_display)

            msg = _(astakos_messages.ACCOUNT_NOT_VERIFIED)

            return ActivationResult(self.Result.ERROR, msg)

        # store a snapshot of user details by the time he

        # got accepted.

        if not user.accepted_email:

            user.accepted_email = user.email

        user.accepted_policy = policy

        user.moderated = True

        user.moderated_at = datetime.datetime.now()

        user.moderated_data = json.dumps(user.__dict__,

                                         default=lambda obj:

                                         str(obj))

        user.save()

        functions.enable_base_project(user)

        if user.is_rejected:

            logger.warning("User has previously been "

                           "rejected, reseting rejection state: %s",

                           user.log_display)

            user.is_rejected = False

            user.rejected_at = None

        user.save()

        logger.info("User accepted: %s", user.log_display)

        self.activate_user(user)

        return ActivationResult(self.Result.ACCEPTED)

    def activate_user(self, user):

        if not user.email_verified:

            msg = _(astakos_messages.ACCOUNT_NOT_VERIFIED)

            return ActivationResult(self.Result.ERROR, msg)

        if not user.moderated:

            msg = _(astakos_messages.ACCOUNT_NOT_MODERATED)

            return ActivationResult(self.Result.ERROR, msg)

        if user.is_rejected:

            msg = _(astakos_messages.ACCOUNT_REJECTED)

            return ActivationResult(self.Result.ERROR, msg)

        if user.is_active:

            msg = _(astakos_messages.ACCOUNT_ALREADY_ACTIVE)

            return ActivationResult(self.Result.ERROR, msg)

        user.is_active = True

        user.deactivated_reason = None

        user.deactivated_at = None

        user.save()

        logger.info("User activated: %s", user.log_display)

        return ActivationResult(self.Result.ACTIVATED)

    def deactivate_user(self, user, reason=''):

        user.is_active = False

        user.deactivated_reason = reason

        if user.is_active:

            user.deactivated_at = datetime.datetime.now()

        user.save()

        logger.info("User deactivated: %s", user.log_display)

        return ActivationResult(self.Result.DEACTIVATED)

    def reject_user(self, user, reason):

        logger.info("Rejecting user: %s", user.log_display)

        if user.moderated:

            logger.warning("User already moderated: %s", user.log_display)

            msg = _(astakos_messages.ACCOUNT_ALREADY_MODERATED)

            return ActivationResult(self.Result.ERROR, msg)

        if user.is_active:

            logger.warning("Cannot reject unverified user: %s",

                           user.log_display)

            msg = _(astakos_messages.ACCOUNT_NOT_VERIFIED)

            return ActivationResult(self.Result.ERROR, msg)

        if not user.email_verified:

            logger.warning("Cannot reject unverified user: %s",

                           user.log_display)

            msg = _(astakos_messages.ACCOUNT_NOT_VERIFIED)

            return ActivationResult(self.Result.ERROR, msg)

        user.moderated = True

        user.moderated_at = datetime.datetime.now()

        user.moderated_data = json.dumps(user.__dict__,

                                         default=lambda obj:

                                         str(obj))

        user.is_rejected = True

        user.rejected_reason = reason

        user.save()

        logger.info("User rejected: %s", user.log_display)

        return ActivationResult(self.Result.REJECTED)

    def handle_registration(self, user, email_verified=False):

        logger.info("Handling new user registration: %s", user.log_display)

        return self.prepare_user(user, email_verified=email_verified)

    def handle_verification(self, user, activation_code):

        logger.info("Handling user email verirfication: %s", user.log_display)

        return self.verify_user(user, activation_code)

    def handle_moderation(self, user, accept=True, reject_reason=None):

        logger.info("Handling user moderation (%r): %s",

                    accept, user.log_display)

        if accept:

            return self.accept_user(user)

        else:

            return self.reject_user(user, reject_reason)

    def send_user_verification_email(self, user):

        if user.is_active:

            raise Exception("User already active")

        # invalidate previous code

        user.renew_verification_code()

        user.save()

        functions.send_verification(user)

        user.activation_sent = datetime.datetime.now()

        user.save()

    def send_result_notifications(self, result, user):

        """

        Send corresponding notifications based on the status of activation

        result.

        Result.PENDING_VERIRFICATION

            * Send user the email verification url

        Result.PENDING_MODERATION

            * Notify admin for account moderation

        Result.ACCEPTED

            * Send user greeting notification

        Result.REJECTED

            * Send nothing

        """

        if result.status == self.Result.PENDING_VERIFICATION:

            logger.info("Sending notifications for user"

                        " creation: %s", user.log_display)

            # email user that contains the activation link

            self.send_user_verification_email(user)

            # TODO: optionally notify admins for new accounts

        if result.status == self.Result.PENDING_MODERATION:

            logger.info("Sending notifications for user"

                        " verification: %s", user.log_display)

            functions.send_account_pending_moderation_notification(

                user,

                self.pending_moderation_template_name)

            # TODO: notify user

        if result.status == self.Result.ACCEPTED:

            logger.info("Sending notifications for user"

                        " moderation: %s", user.log_display)

            functions.send_account_activated_notification(

                user,

                self.activated_email_template_name)

            functions.send_greeting(user,

                                    self.greeting_template_name)

            # TODO: notify admins

        if result.status == self.Result.REJECTED:

            logger.info("Sending notifications for user"

                        " rejection: %s", user.log_display)

            # TODO: notify user and admins

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, invitation, provider='local', initial_data=None,

                        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 = invitation

        prefix = 'Invited' if invitation else ''

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

        suffix = 'UserCreationForm'

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

        return formclass(initial_data, instance=instance)

    def get_signup_initial_data(self, request, provider):

        """

        Returns the necassary activation form depending the user is invited or

        not.

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

        """

        invitation = self.invitation

        initial_data = None

        if request.method == 'GET':

            if invitation:

                first, last = models.split_realname(invitation.realname)

                initial_data = {'email': invitation.username,

                                'inviter': invitation.inviter.realname,

                                'first_name': first,

                                'last_name': last,

                                'provider': provider}

        else:

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

                initial_data = request.POST

        return initial_data

    def _is_preaccepted(self, user):

        """

        Extends _is_preaccepted and if there is a valid, not-consumed

        invitation code for the specific user returns True else returns False.

        """

        preaccepted = super(InvitationsBackend, self)._is_preaccepted(user)

        if preaccepted:

            return preaccepted

        invitation = self.invitation

        if not invitation:

            if not self.moderation_enabled:

                return 'auto_moderation'

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

            invitation.consume()

            return 'invitation'

        return False

class SimpleBackend(ActivationBackend):

    """

    The common activation backend.

    """

# shortcut

ActivationResultStatus = ActivationBackend.Result

class ActivationResult(object):

    MESSAGE_BY_STATUS = {

        ActivationResultStatus.PENDING_VERIFICATION:

        _(astakos_messages.VERIFICATION_SENT),

        ActivationResultStatus.PENDING_MODERATION:

        _(astakos_messages.NOTIFICATION_SENT),

        ActivationResultStatus.ACCEPTED:

        _(astakos_messages.ACCOUNT_ACTIVATED),

        ActivationResultStatus.ACTIVATED:

        _(astakos_messages.ACCOUNT_ACTIVATED),

        ActivationResultStatus.DEACTIVATED:

        _(astakos_messages.ACCOUNT_DEACTIVATED),

        ActivationResultStatus.ERROR:

        _(astakos_messages.GENERIC_ERROR)

    }

    STATUS_DISPLAY = {

        ActivationResultStatus.PENDING_VERIFICATION: 'PENDING_VERIFICATION',

        ActivationResultStatus.PENDING_MODERATION: 'PENDING_MODERATION',

        ActivationResultStatus.ACCEPTED: 'ACCEPTED',

        ActivationResultStatus.ACTIVATED: 'ACTIVATED',

        ActivationResultStatus.DEACTIVATED: 'DEACTIVATED',

        ActivationResultStatus.ERROR: 'ERROR'

    }

    def __init__(self, status, message=None):

        if message is None:

            message = self.MESSAGE_BY_STATUS.get(status)

        self.message = message

        self.status = status

    def status_display(self):

        return self.STATUS_DISPLAY.get(self.status)

    def __repr__(self):

        return "ActivationResult [%s]: %s" % (self.status_display(),

                                              self.message)

    def is_error(self):

        return self.status == ActivationResultStatus.ERROR