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:

#

#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   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.

#

# 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,

# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

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

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

# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

#

# The views and conclusions contained in the software and

# documentation are those of the authors and should not be

# interpreted as representing official policies, either expressed

# or implied, of GRNET S.A.

import logging

import socket

from django.utils.translation import ugettext as _

from django.template.loader import render_to_string

from django.core.mail import send_mail, get_connection

from django.core.urlresolvers import reverse

from django.template import Context, loader

from django.contrib.auth import (

    login as auth_login,

    logout as auth_logout)

from django.conf import settings

from django.contrib.auth.models import AnonymousUser

from django.core.exceptions import PermissionDenied

from django.db import IntegrityError

from django.http import Http404

from urllib import quote

from urlparse import urljoin

from smtplib import SMTPException

from datetime import datetime

from functools import wraps

from astakos.im.settings import (

    DEFAULT_CONTACT_EMAIL, SITENAME, BASEURL, LOGGING_LEVEL,

    VERIFICATION_EMAIL_SUBJECT, ACCOUNT_CREATION_SUBJECT,

    GROUP_CREATION_SUBJECT, HELPDESK_NOTIFICATION_EMAIL_SUBJECT,

    INVITATION_EMAIL_SUBJECT, GREETING_EMAIL_SUBJECT, FEEDBACK_EMAIL_SUBJECT,

    EMAIL_CHANGE_EMAIL_SUBJECT,

    PROJECT_CREATION_SUBJECT, PROJECT_APPROVED_SUBJECT,

    PROJECT_TERMINATION_SUBJECT, PROJECT_SUSPENSION_SUBJECT,

    PROJECT_MEMBERSHIP_CHANGE_SUBJECT,

    PROJECT_MEMBER_JOIN_POLICIES, PROJECT_MEMBER_LEAVE_POLICIES)

from astakos.im.notifications import build_notification, NotificationError

from astakos.im.models import (

    AstakosUser, ProjectMembership, ProjectApplication, Project,

    PendingMembershipError, get_resource_names, new_chain)

from astakos.im.project_notif import (

    membership_change_notify, membership_enroll_notify,

    membership_request_notify, membership_leave_request_notify,

    application_submit_notify, application_approve_notify,

    application_deny_notify,

    project_termination_notify, project_suspension_notify)

from astakos.im.endpoints.qh import qh_register_user_with_quotas, qh_get_quota

import astakos.im.messages as astakos_messages

logger = logging.getLogger(__name__)

def logged(func, msg):

    @wraps(func)

    def with_logging(*args, **kwargs):

        email = ''

        user = None

        try:

            request = args[0]

            email = request.user.email

        except (KeyError, AttributeError), e:

            email = ''

        r = func(*args, **kwargs)

        if LOGGING_LEVEL:

            logger.log(LOGGING_LEVEL, msg % email)

        return r

    return with_logging

def login(request, user):

    auth_login(request, user)

    from astakos.im.models import SessionCatalog

    SessionCatalog(

        session_key=request.session.session_key,

        user=user

    ).save()

login = logged(login, '%s logged in.')

logout = logged(auth_logout, '%s logged out.')

def send_verification(user, template_name='im/activation_email.txt'):

    """

    Send email to user to verify his/her email and activate his/her account.

    Raises SendVerificationError

    """

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

                                  quote(user.auth_token),

                                  quote(urljoin(BASEURL, reverse('index'))))

    message = render_to_string(template_name, {

                               'user': user,

                               'url': url,

                               'baseurl': BASEURL,

                               'site_name': SITENAME,

                               'support': DEFAULT_CONTACT_EMAIL})

    sender = settings.SERVER_EMAIL

    try:

        send_mail(_(VERIFICATION_EMAIL_SUBJECT), message, sender, [user.email],

                  connection=get_connection())

    except (SMTPException, socket.error) as e:

        logger.exception(e)

        raise SendVerificationError()

    else:

        msg = 'Sent activation %s' % user.email

        logger.log(LOGGING_LEVEL, msg)

def send_activation(user, template_name='im/activation_email.txt'):

    send_verification(user, template_name)

    user.activation_sent = datetime.now()

    user.save()

def _send_admin_notification(template_name,

                             dictionary=None,

                             subject='alpha2 testing notification',):

    """

    Send notification email to settings.ADMINS.

    Raises SendNotificationError

    """

    if not settings.ADMINS:

        return

    dictionary = dictionary or {}

    message = render_to_string(template_name, dictionary)

    sender = settings.SERVER_EMAIL

    try:

        send_mail(subject, message, sender, [i[1] for i in settings.ADMINS],

                  connection=get_connection())

    except (SMTPException, socket.error) as e:

        logger.exception(e)

        raise SendNotificationError()

    else:

        msg = 'Sent admin notification for user %s' % dictionary.get('email',

                                                                     None)

        logger.log(LOGGING_LEVEL, msg)

def send_account_creation_notification(template_name, dictionary=None):

    user = dictionary.get('user', AnonymousUser())

    subject = _(ACCOUNT_CREATION_SUBJECT) % {'user':user.get('email', '')}

    return _send_admin_notification(template_name, dictionary, subject=subject)

def send_helpdesk_notification(user, template_name='im/helpdesk_notification.txt'):

    """

    Send email to DEFAULT_CONTACT_EMAIL to notify for a new user activation.

    Raises SendNotificationError

    """

    if not DEFAULT_CONTACT_EMAIL:

        return

    message = render_to_string(

        template_name,

        {'user': user}

    )

    sender = settings.SERVER_EMAIL

    try:

        send_mail(_(HELPDESK_NOTIFICATION_EMAIL_SUBJECT) % {'user': user.email},

                  message, sender, [DEFAULT_CONTACT_EMAIL],

                  connection=get_connection())

    except (SMTPException, socket.error) as e:

        logger.exception(e)

        raise SendNotificationError()

    else:

        msg = 'Sent helpdesk admin notification for %s' % user.email

        logger.log(LOGGING_LEVEL, msg)

def send_invitation(invitation, template_name='im/invitation.txt'):

    """

    Send invitation email.

    Raises SendInvitationError

    """

    subject = _(INVITATION_EMAIL_SUBJECT)

    url = '%s?code=%d' % (urljoin(BASEURL, reverse('index')), invitation.code)

    message = render_to_string(template_name, {

                               'invitation': invitation,

                               'url': url,

                               'baseurl': BASEURL,

                               'site_name': SITENAME,

                               'support': DEFAULT_CONTACT_EMAIL})

    sender = settings.SERVER_EMAIL

    try:

        send_mail(subject, message, sender, [invitation.username],

                  connection=get_connection())

    except (SMTPException, socket.error) as e:

        logger.exception(e)

        raise SendInvitationError()

    else:

        msg = 'Sent invitation %s' % invitation

        logger.log(LOGGING_LEVEL, msg)

        inviter_invitations = invitation.inviter.invitations

        invitation.inviter.invitations = max(0, inviter_invitations - 1)

        invitation.inviter.save()

def send_greeting(user, email_template_name='im/welcome_email.txt'):

    """

    Send welcome email.

    Raises SMTPException, socket.error

    """

    subject = _(GREETING_EMAIL_SUBJECT)

    message = render_to_string(email_template_name, {

                               'user': user,

                               'url': urljoin(BASEURL, reverse('index')),

                               'baseurl': BASEURL,

                               'site_name': SITENAME,

                               'support': DEFAULT_CONTACT_EMAIL})

    sender = settings.SERVER_EMAIL

    try:

        send_mail(subject, message, sender, [user.email],

                  connection=get_connection())

    except (SMTPException, socket.error) as e:

        logger.exception(e)

        raise SendGreetingError()

    else:

        msg = 'Sent greeting %s' % user.email

        logger.log(LOGGING_LEVEL, msg)

def send_feedback(msg, data, user, email_template_name='im/feedback_mail.txt'):

    subject = _(FEEDBACK_EMAIL_SUBJECT)

    from_email = settings.SERVER_EMAIL

    recipient_list = [DEFAULT_CONTACT_EMAIL]

    content = render_to_string(email_template_name, {

        'message': msg,

        'data': data,

        'user': user})

    try:

        send_mail(subject, content, from_email, recipient_list,

                  connection=get_connection())

    except (SMTPException, socket.error) as e:

        logger.exception(e)

        raise SendFeedbackError()

    else:

        msg = 'Sent feedback from %s' % user.email

        logger.log(LOGGING_LEVEL, msg)

def send_change_email(

    ec, request, email_template_name='registration/email_change_email.txt'):

    try:

        url = ec.get_url()

        url = request.build_absolute_uri(url)

        t = loader.get_template(email_template_name)

        c = {'url': url, 'site_name': SITENAME}

        from_email = settings.SERVER_EMAIL

        send_mail(_(EMAIL_CHANGE_EMAIL_SUBJECT), t.render(Context(c)),

                  from_email, [ec.new_email_address],

                  connection=get_connection())

    except (SMTPException, socket.error) as e:

        logger.exception(e)

        raise ChangeEmailError()

    else:

        msg = 'Sent change email for %s' % ec.user.email

        logger.log(LOGGING_LEVEL, msg)

def activate(

    user,

    email_template_name='im/welcome_email.txt',

    helpdesk_email_template_name='im/helpdesk_notification.txt',

    verify_email=False):

    """

    Activates the specific user and sends email.

    Raises SendGreetingError, ValidationError

    """

    user.is_active = True

    user.email_verified = True

    if not user.activation_sent:

        user.activation_sent = datetime.now()

    user.save()

    qh_register_user_with_quotas(user)

    send_helpdesk_notification(user, helpdesk_email_template_name)

    send_greeting(user, email_template_name)

def deactivate(user):

    user.is_active = False

    user.save()

def invite(inviter, email, realname):

    inv = Invitation(inviter=inviter, username=email, realname=realname)

    inv.save()

    send_invitation(inv)

    inviter.invitations = max(0, self.invitations - 1)

    inviter.save()

def switch_account_to_shibboleth(user, local_user,

                                 greeting_template_name='im/welcome_email.txt'):

    try:

        provider = user.provider

    except AttributeError:

        return

    else:

        if not provider == 'shibboleth':

            return

        user.delete()

        local_user.provider = 'shibboleth'

        local_user.third_party_identifier = user.third_party_identifier

        local_user.save()

        send_greeting(local_user, greeting_template_name)

        return local_user

class SendMailError(Exception):

    pass

class SendAdminNotificationError(SendMailError):

    def __init__(self):

        self.message = _(astakos_messages.ADMIN_NOTIFICATION_SEND_ERR)

        super(SendAdminNotificationError, self).__init__()

class SendVerificationError(SendMailError):

    def __init__(self):

        self.message = _(astakos_messages.VERIFICATION_SEND_ERR)

        super(SendVerificationError, self).__init__()

class SendInvitationError(SendMailError):

    def __init__(self):

        self.message = _(astakos_messages.INVITATION_SEND_ERR)

        super(SendInvitationError, self).__init__()

class SendGreetingError(SendMailError):

    def __init__(self):

        self.message = _(astakos_messages.GREETING_SEND_ERR)

        super(SendGreetingError, self).__init__()

class SendFeedbackError(SendMailError):

    def __init__(self):

        self.message = _(astakos_messages.FEEDBACK_SEND_ERR)

        super(SendFeedbackError, self).__init__()

class ChangeEmailError(SendMailError):

    def __init__(self):

        self.message = _(astakos_messages.CHANGE_EMAIL_SEND_ERR)

        super(ChangeEmailError, self).__init__()

class SendNotificationError(SendMailError):

    def __init__(self):

        self.message = _(astakos_messages.NOTIFICATION_SEND_ERR)

        super(SendNotificationError, self).__init__()

def get_quota(users):

    resources = get_resource_names()

    return qh_get_quota(users, resources)

### PROJECT VIEWS ###

AUTO_ACCEPT_POLICY = 1

MODERATED_POLICY   = 2

CLOSED_POLICY      = 3

POLICIES = [ AUTO_ACCEPT_POLICY, MODERATED_POLICY, CLOSED_POLICY ]

def get_project_by_application_id(project_application_id):

    try:

        return Project.objects.get(application__id=project_application_id)

    except Project.DoesNotExist:

        raise IOError(

            _(astakos_messages.UNKNOWN_PROJECT_APPLICATION_ID) % project_application_id)

def get_related_project_id(application_id):

    try:

        app = ProjectApplication.objects.get(id=application_id)

        chain = app.chain

        project = Project.objects.get(id=chain)

        return chain

    except:

        return None

def get_project_by_id(project_id):

    try:

        return Project.objects.get(id=project_id)

    except Project.DoesNotExist:

        raise IOError(

            _(astakos_messages.UNKNOWN_PROJECT_ID) % project_id)

def get_project_for_update(project_id):

    try:

        return Project.objects.select_for_update().get(id=project_id)

    except Project.DoesNotExist:

        raise IOError(

            _(astakos_messages.UNKNOWN_PROJECT_ID) % project_id)

def get_application_for_update(application_id):

    try:

        objects = ProjectApplication.objects.select_for_update()

        return objects.get(id=application_id)

    except ProjectApplication.DoesNotExist:

        m = _(astakos_messages.UNKNOWN_PROJECT_APPLICATION_ID) % application_id

        raise IOError(m)

def get_user_by_id(user_id):

    try:

        return AstakosUser.objects.get(id=user_id)

    except AstakosUser.DoesNotExist:

        raise IOError(_(astakos_messages.UNKNOWN_USER_ID) % user_id)

def get_user_by_uuid(uuid):

    try:

        return AstakosUser.objects.get(uuid=uuid)

    except AstakosUser.DoesNotExist:

        raise IOError(_(astakos_messages.UNKNOWN_USER_ID) % user_id)

def create_membership(project, user):

    if isinstance(project, int):

        project = get_project_by_id(project)

    if isinstance(user, int):

        user = get_user_by_id(user)

    m = ProjectMembership(

        project=project,

        person=user,

        request_date=datetime.now())

    try:

        m.save()

    except IntegrityError, e:

        raise IOError(_(astakos_messages.MEMBERSHIP_REQUEST_EXISTS))

    else:

        return m

def get_membership_for_update(project, user):

    if isinstance(project, int):

        project = get_project_by_id(project)

    if isinstance(user, int):

        user = get_user_by_id(user)

    try:

        sfu = ProjectMembership.objects.select_for_update()

        m = sfu.get(project=project, person=user)

        if m.is_pending:

            raise PendingMembershipError()

        return m

    except ProjectMembership.DoesNotExist:

        raise IOError(_(astakos_messages.NOT_MEMBERSHIP_REQUEST))

def checkAllowed(entity, request_user):

    if isinstance(entity, Project):

        application = entity.application

    elif isinstance(entity, ProjectApplication):

        application = entity

    else:

        m = "%s not a Project nor a ProjectApplication" % (entity,)

        raise ValueError(m)

    if request_user and \

        (not application.owner == request_user and \

            not request_user.is_superuser):

        raise PermissionDenied(_(astakos_messages.NOT_ALLOWED))

def checkAlive(project):

    if not project.is_alive:

        raise PermissionDenied(

            _(astakos_messages.NOT_ALIVE_PROJECT) % project.__dict__)

def accept_membership_checks(project, request_user):

    checkAllowed(project, request_user)

    checkAlive(project)

    join_policy = project.application.member_join_policy

    if join_policy == CLOSED_POLICY:

        raise PermissionDenied(_(astakos_messages.MEMBER_JOIN_POLICY_CLOSED))

    if project.violates_members_limit(adding=1):

        raise PermissionDenied(_(astakos_messages.MEMBER_NUMBER_LIMIT_REACHED))

def accept_membership(project_id, user, request_user=None):

    project = get_project_for_update(project_id)

    accept_membership_checks(project, request_user)

    membership = get_membership_for_update(project, user)

    if not membership.can_accept():

        m = _(astakos_messages.NOT_MEMBERSHIP_REQUEST)

        raise PermissionDenied(m)

    membership.accept()

    membership_change_notify(project, membership.person, 'accepted')

    return membership

def reject_membership_checks(project, request_user):

    checkAllowed(project, request_user)

    checkAlive(project)

def reject_membership(project_id, user, request_user=None):

    project = get_project_for_update(project_id)

    reject_membership_checks(project, request_user)

    membership = get_membership_for_update(project, user)

    if not membership.can_reject():

        m = _(astakos_messages.NOT_MEMBERSHIP_REQUEST)

        raise PermissionDenied(m)

    membership.reject()

    membership_change_notify(project, membership.person, 'rejected')

    return membership

def cancel_membership_checks(project):

    checkAlive(project)

def cancel_membership(project_id, user_id):

    project = get_project_for_update(project_id)

    cancel_membership_checks(project)

    membership = get_membership_for_update(project, user_id)

    if not membership.can_cancel():

        m = _(astakos_messages.NOT_MEMBERSHIP_REQUEST)

        raise PermissionDenied(m)

    membership.cancel()

def remove_membership_checks(project, request_user=None):

    checkAllowed(project, request_user)

    checkAlive(project)

    leave_policy = project.application.member_leave_policy

    if leave_policy == CLOSED_POLICY:

        raise PermissionDenied(_(astakos_messages.MEMBER_LEAVE_POLICY_CLOSED))

def remove_membership(project_id, user, request_user=None):

    project = get_project_for_update(project_id)

    remove_membership_checks(project, request_user)

    membership = get_membership_for_update(project, user)

    if not membership.can_remove():

        m = _(astakos_messages.NOT_ACCEPTED_MEMBERSHIP)

        raise PermissionDenied(m)

    membership.remove()

    membership_change_notify(project, membership.person, 'removed')

    return membership

def enroll_member(project_id, user, request_user=None):

    project = get_project_for_update(project_id)

    accept_membership_checks(project, request_user)

    membership = create_membership(project_id, user)

    if not membership.can_accept():

        m = _(astakos_messages.NOT_MEMBERSHIP_REQUEST)

        raise PermissionDenied(m)

    membership.accept()

    membership_enroll_notify(project, membership.person)

    return membership

def leave_project_checks(project):

    checkAlive(project)

    leave_policy = project.application.member_leave_policy

    if leave_policy == CLOSED_POLICY:

        raise PermissionDenied(_(astakos_messages.MEMBER_LEAVE_POLICY_CLOSED))

def can_leave_request(project, user):

    leave_policy = project.application.member_leave_policy

    if leave_policy == CLOSED_POLICY:

        return False

    m = user.get_membership(project)

    if m is None:

        return False

    if m.state != ProjectMembership.ACCEPTED:

        return False

    return True

def leave_project(project_id, user_id):

    project = get_project_for_update(project_id)

    leave_project_checks(project)

    membership = get_membership_for_update(project, user_id)

    if not membership.can_leave():

        m = _(astakos_messages.NOT_ACCEPTED_MEMBERSHIP)

        raise PermissionDenied(m)

    auto_accepted = False

    leave_policy = project.application.member_leave_policy

    if leave_policy == AUTO_ACCEPT_POLICY:

        membership.remove()

        auto_accepted = True

    else:

        membership.leave_request_date = datetime.now()

        membership.save()

        membership_leave_request_notify(project, membership.person)

    return auto_accepted

def join_project_checks(project):

    checkAlive(project)

    join_policy = project.application.member_join_policy

    if join_policy == CLOSED_POLICY:

        raise PermissionDenied(_(astakos_messages.MEMBER_JOIN_POLICY_CLOSED))

def can_join_request(project, user):

    join_policy = project.application.member_join_policy

    if join_policy == CLOSED_POLICY:

        return False

    m = user.get_membership(project)

    if m:

        return False

    return True

def join_project(project_id, user_id):

    project = get_project_for_update(project_id)

    join_project_checks(project)

    membership = create_membership(project, user_id)

    auto_accepted = False

    join_policy = project.application.member_join_policy

    if (join_policy == AUTO_ACCEPT_POLICY and

        not project.violates_members_limit(adding=1)):

        membership.accept()

        auto_accepted = True

    else:

        membership_request_notify(project, membership.person)

    return auto_accepted

def submit_application(kw, request_user=None):

    kw['applicant'] = request_user

    resource_policies = kw.pop('resource_policies', None)

    precursor = None

    precursor_id = kw.get('precursor_application', None)

    if precursor_id is not None:

        sfu = ProjectApplication.objects.select_for_update()

        precursor = sfu.get(id=precursor_id)

        kw['precursor_application'] = precursor

        if (request_user and

            (not precursor.owner == request_user and

             not request_user.is_superuser

             and not request_user.is_project_admin())):

            m = _(astakos_messages.NOT_ALLOWED)

            raise PermissionDenied(m)

    application = ProjectApplication(**kw)

    if precursor is None:

        application.chain = new_chain()

    else:

        chain = precursor.chain

        application.chain = chain

        sfu = ProjectApplication.objects.select_for_update()

        pending = sfu.filter(chain=chain, state=ProjectApplication.PENDING)

        for app in pending:

            app.state = ProjectApplication.REPLACED

            app.save()

    application.save()

    application.resource_policies = resource_policies

    application_submit_notify(application)

    return application

def cancel_application(application_id, request_user=None):

    application = get_application_for_update(application_id)

    checkAllowed(application, request_user)

    if not application.can_cancel():

        m = _(astakos_messages.APPLICATION_CANNOT_CANCEL % (

                application.id, application.state_display()))

        raise PermissionDenied(m)

    application.cancel()

def dismiss_application(application_id, request_user=None):

    application = get_application_for_update(application_id)

    checkAllowed(application, request_user)

    if not application.can_dismiss():

        m = _(astakos_messages.APPLICATION_CANNOT_DISMISS % (

                application.id, application.state_display()))

        raise PermissionDenied(m)

    application.dismiss()

def deny_application(application_id):

    application = get_application_for_update(application_id)

    if not application.can_deny():

        m = _(astakos_messages.APPLICATION_CANNOT_DENY % (

                application.id, application.state_display()))

        raise PermissionDenied(m)

    application.deny()

    application_deny_notify(application)

def approve_application(app_id):

    try:

        objects = ProjectApplication.objects.select_for_update()

        application = objects.get(id=app_id)

    except ProjectApplication.DoesNotExist:

        m = _(astakos_messages.UNKNOWN_PROJECT_APPLICATION_ID % (app_id,))

        raise PermissionDenied(m)

    if not application.can_approve():

        m = _(astakos_messages.APPLICATION_CANNOT_APPROVE % (

                application.id, application.state_display()))

        raise PermissionDenied(m)

    application.approve()

    application_approve_notify(application)

def check_expiration(execute=False):

    objects = Project.objects

    expired = objects.expired_projects()

    if execute:

        for project in expired:

            terminate(project.id)

    return [project.expiration_info() for project in expired]

def terminate(project_id):

    project = get_project_for_update(project_id)

    checkAlive(project)

    project.terminate()

    project_termination_notify(project)

def suspend(project_id):

    project = get_project_by_id(project_id)

    checkAlive(project)

    project.suspend()

    project_suspension_notify(project)

def resume(project_id):

    project = get_project_for_update(project_id)

    if not project.is_suspended:

        m = _(astakos_messages.NOT_SUSPENDED_PROJECT) % project.__dict__

        raise PermissionDenied(m)

    project.resume()

def get_by_chain_or_404(chain_id):

    try:

        project = Project.objects.get(id=chain_id)

        application = project.application

        return project, application

    except:

        application = ProjectApplication.objects.latest_of_chain(chain_id)

        if application is None:

            raise Http404

        else:

            return None, application