Synnefo

# Copyright 2011-2012 GRNET S.A. All rights reserved.

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# without modification, are permitted provided that the following

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#      disclaimer.

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#      disclaimer in the documentation and/or other materials

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import logging

import time

import urllib

from urlparse import urlparse

from datetime import tzinfo, timedelta

from django.http import HttpResponse, HttpResponseBadRequest, urlencode

from django.template import RequestContext

from django.contrib.auth import authenticate

from django.core.urlresolvers import reverse

from django.shortcuts import redirect

from django.core.exceptions import ValidationError, ObjectDoesNotExist

from django.utils.translation import ugettext as _

from astakos.im.models import AstakosUser, Invitation

from astakos.im.functions import login

from astakos.im import settings

import astakos.im.messages as astakos_messages

logger = logging.getLogger(__name__)

class UTC(tzinfo):

    def utcoffset(self, dt):

        return timedelta(0)

    def tzname(self, dt):

        return 'UTC'

    def dst(self, dt):

        return timedelta(0)

def isoformat(d):

    """Return an ISO8601 date string that includes a timezone."""

    return d.replace(tzinfo=UTC()).isoformat()

def epoch(dt):

    return int(time.mktime(dt.timetuple()) * 1000)

def get_context(request, extra_context=None, **kwargs):

    extra_context = extra_context or {}

    extra_context.update(kwargs)

    return RequestContext(request, extra_context)

def get_invitation(request):

    """

    Returns the invitation identified by the ``code``.

    Raises ValueError if the invitation is consumed or there is another account

    associated with this email.

    """

    code = request.GET.get('code')

    if request.method == 'POST':

        code = request.POST.get('code')

    if not code:

        return

    invitation = Invitation.objects.get(code=code)

    if invitation.is_consumed:

        raise ValueError(_(astakos_messages.INVITATION_CONSUMED_ERR))

    if reserved_email(invitation.username):

        email = invitation.username

        raise ValueError(_(astakos_messages.EMAIL_RESERVED) % locals())

    return invitation

def restrict_next(url, domain=None, allowed_schemes=()):

    """

    Utility method to validate that provided url is safe to be used as the

    redirect location of an http redirect response. The method parses the

    provided url and identifies if it conforms CORS against provided domain

    AND url scheme matches any of the schemes in `allowed_schemes` parameter.

    If verirication succeeds sanitized safe url is returned. Consider using

    the method's result in the response location header and not the originally

    provided url. If verification fails the method returns None.

    >>> print restrict_next('/im/feedback', '.okeanos.grnet.gr')

    /im/feedback

    >>> print restrict_next('pithos.okeanos.grnet.gr/im/feedback',

    ...                     '.okeanos.grnet.gr')

    //pithos.okeanos.grnet.gr/im/feedback

    >>> print restrict_next('https://pithos.okeanos.grnet.gr/im/feedback',

    ...                     '.okeanos.grnet.gr')

    https://pithos.okeanos.grnet.gr/im/feedback

    >>> print restrict_next('pithos://127.0.0.1', '.okeanos.grnet.gr')

    None

    >>> print restrict_next('pithos://127.0.0.1', '.okeanos.grnet.gr',

    ...                     allowed_schemes=('pithos'))

    None

    >>> print restrict_next('pithos://127.0.0.1', '127.0.0.1',

    ...                     allowed_schemes=('pithos'))

    pithos://127.0.0.1

    >>> print restrict_next('node1.example.com', '.okeanos.grnet.gr')

    None

    >>> print restrict_next('//node1.example.com', '.okeanos.grnet.gr')

    None

    >>> print restrict_next('https://node1.example.com', '.okeanos.grnet.gr')

    None

    >>> print restrict_next('https://node1.example.com')

    https://node1.example.com

    >>> print restrict_next('//node1.example.com')

    //node1.example.com

    >>> print restrict_next('node1.example.com')

    //node1.example.com

    >>> print restrict_next('node1.example.com', allowed_schemes=('pithos',))

    None

    >>> print restrict_next('pithos://localhost', 'localhost',

    ...                     allowed_schemes=('pithos',))

    pithos://localhost

    """

    if not url:

        return None

    parts = urlparse(url, scheme='http')

    if not parts.netloc and not parts.path.startswith('/'):

        # fix url if does not conforms RFC 1808

        url = '//%s' % url

        parts = urlparse(url, scheme='http')

    if not domain and not allowed_schemes:

        return url

    # domain validation

    if domain:

        if not parts.netloc:

            return url

        if parts.netloc.endswith(domain):

            return url

        else:

            return None

    # scheme validation

    if allowed_schemes:

        if parts.scheme in allowed_schemes:

            return url

    return None

def prepare_response(request, user, next='', renew=False):

    """Return the unique username and the token

       as 'X-Auth-User' and 'X-Auth-Token' headers,

       or redirect to the URL provided in 'next'

       with the 'user' and 'token' as parameters.

       Reissue the token even if it has not yet

       expired, if the 'renew' parameter is present

       or user has not a valid token.

    """

    renew = renew or (not user.auth_token)

    renew = renew or user.token_expired()

    if renew:

        user.renew_token(

            flush_sessions=True,

            current_key=request.session.session_key

        )

        try:

            user.save()

        except ValidationError, e:

            return HttpResponseBadRequest(e)

    next = restrict_next(next, domain=settings.COOKIE_DOMAIN)

    if settings.FORCE_PROFILE_UPDATE and \

            not user.is_verified and not user.is_superuser:

        params = ''

        if next:

            params = '?' + urlencode({'next': next})

        next = reverse('edit_profile') + params

    response = HttpResponse()

    # authenticate before login

    user = authenticate(email=user.email, auth_token=user.auth_token)

    login(request, user)

    request.session.set_expiry(user.auth_token_expires)

    if not next:

        next = settings.LOGIN_SUCCESS_URL

    response['Location'] = next

    response.status_code = 302

    return response

class lazy_string(object):

    def __init__(self, function, *args, **kwargs):

        self.function = function

        self.args = args

        self.kwargs = kwargs

    def __str__(self):

        if not hasattr(self, 'str'):

            self.str = self.function(*self.args, **self.kwargs)

        return self.str

def reverse_lazy(*args, **kwargs):

    return lazy_string(reverse, *args, **kwargs)

def reserved_email(email):

    return AstakosUser.objects.user_exists(email)

def reserved_verified_email(email):

    return AstakosUser.objects.verified_user_exists(email)

def get_query(request):

    try:

        return request.__getattribute__(request.method)

    except AttributeError:

        return {}

def get_properties(obj):

    def get_class_attr(_class, attr):

        try:

            return getattr(_class, attr)

        except AttributeError:

            return

    return (i for i in vars(obj.__class__)

            if isinstance(get_class_attr(obj.__class__, i), property))

def model_to_dict(obj, exclude=None, include_empty=True):

    '''

        serialize model object to dict with related objects

        author: Vadym Zakovinko <vp@zakovinko.com>

        date: January 31, 2011

        http://djangosnippets.org/snippets/2342/

    '''

    if exclude is None:

        exclude = ['AutoField', 'ForeignKey', 'OneToOneField']

    tree = {}

    for field_name in obj._meta.get_all_field_names():

        try:

            field = getattr(obj, field_name)

        except (ObjectDoesNotExist, AttributeError):

            continue

        if field.__class__.__name__ in ['RelatedManager',

                                        'ManyRelatedManager']:

            if field.model.__name__ in exclude:

                continue

            if field.__class__.__name__ == 'ManyRelatedManager':

                exclude.append(obj.__class__.__name__)

            subtree = []

            for related_obj in getattr(obj, field_name).all():

                value = model_to_dict(related_obj, exclude=exclude)

                if value or include_empty:

                    subtree.append(value)

            if subtree or include_empty:

                tree[field_name] = subtree

            continue

        field = obj._meta.get_field_by_name(field_name)[0]

        if field.__class__.__name__ in exclude:

            continue

        if field.__class__.__name__ == 'RelatedObject':

            exclude.append(field.model.__name__)

            tree[field_name] = model_to_dict(getattr(obj, field_name),

                                             exclude=exclude)

            continue

        value = getattr(obj, field_name)

        if field.__class__.__name__ == 'ForeignKey':

            value = unicode(value) if value is not None else value

        if value or include_empty:

            tree[field_name] = value

    properties = list(get_properties(obj))

    for p in properties:

        tree[p] = getattr(obj, p)

    tree['str_repr'] = obj.__str__()

    return tree

def login_url(request):

    attrs = {}

    for attr in ['login', 'key', 'code']:

        val = request.REQUEST.get(attr, None)

        if val:

            attrs[attr] = val

    return "%s?%s" % (reverse('login'), urllib.urlencode(attrs))

def redirect_back(request, default='index'):

    """

    Redirect back to referer if safe and possible.

    """

    referer = request.META.get('HTTP_REFERER')

    safedomain = settings.BASE_URL.replace("https://", "").replace(

        "http://", "")

    safe = restrict_next(referer, safedomain)

    # avoid redirect loop

    loops = referer == request.get_full_path()

    if referer and safe and not loops:

        return redirect(referer)

    return redirect(reverse(default))