Synnefo

# Copyright 2011, 2012, 2013 GRNET S.A. All rights reserved.

#

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# 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,

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

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# 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 hashlib

import uuid

import logging

import json

import math

import copy

from time import asctime

from datetime import datetime, timedelta

from base64 import b64encode

from urlparse import urlparse

from urllib import quote

from random import randint

from collections import defaultdict, namedtuple

from django.db import models, IntegrityError, transaction

from django.contrib.auth.models import User, UserManager, Group, Permission

from django.utils.translation import ugettext as _

from django.core.exceptions import ValidationError

from django.db.models.signals import (

    pre_save, post_save, post_syncdb, post_delete)

from django.contrib.contenttypes.models import ContentType

from django.dispatch import Signal

from django.db.models import Q, Max

from django.core.urlresolvers import reverse

from django.utils.http import int_to_base36

from django.contrib.auth.tokens import default_token_generator

from django.conf import settings

from django.utils.importlib import import_module

from django.utils.safestring import mark_safe

from django.core.validators import email_re

from django.core.exceptions import PermissionDenied, ObjectDoesNotExist

from astakos.im.settings import (

    DEFAULT_USER_LEVEL, INVITATIONS_PER_LEVEL,

    AUTH_TOKEN_DURATION, EMAILCHANGE_ACTIVATION_DAYS, LOGGING_LEVEL,

    SITENAME, SERVICES, MODERATION_ENABLED, RESOURCES_PRESENTATION_DATA,

    PROJECT_MEMBER_JOIN_POLICIES, PROJECT_MEMBER_LEAVE_POLICIES, PROJECT_ADMINS)

from astakos.im import settings as astakos_settings

from astakos.im.endpoints.qh import (

    send_quotas, qh_get_quotas,

    register_resources, qh_add_quota, QuotaLimits,

    )

from astakos.im import auth_providers as auth

import astakos.im.messages as astakos_messages

from synnefo.lib.db.managers import ForUpdateManager

from astakos.quotaholder.api import QH_PRACTICALLY_INFINITE

from synnefo.lib.db.intdecimalfield import intDecimalField

from synnefo.util.text import uenc, udec

logger = logging.getLogger(__name__)

DEFAULT_CONTENT_TYPE = None

_content_type = None

def get_content_type():

    global _content_type

    if _content_type is not None:

        return _content_type

    try:

        content_type = ContentType.objects.get(app_label='im', model='astakosuser')

    except:

        content_type = DEFAULT_CONTENT_TYPE

    _content_type = content_type

    return content_type

RESOURCE_SEPARATOR = '.'

inf = float('inf')

class Service(models.Model):

    name = models.CharField(_('Name'), max_length=255, unique=True, db_index=True)

    url = models.FilePathField()

    icon = models.FilePathField(blank=True)

    auth_token = models.CharField(_('Authentication Token'), max_length=32,

                                  null=True, blank=True)

    auth_token_created = models.DateTimeField(_('Token creation date'), null=True)

    auth_token_expires = models.DateTimeField(

        _('Token expiration date'), null=True)

    order = models.PositiveIntegerField(default=0)

    class Meta:

        ordering = ('order', )

    def renew_token(self, expiration_date=None):

        md5 = hashlib.md5()

        md5.update(self.name.encode('ascii', 'ignore'))

        md5.update(self.url.encode('ascii', 'ignore'))

        md5.update(asctime())

        self.auth_token = b64encode(md5.digest())

        self.auth_token_created = datetime.now()

        if expiration_date:

            self.auth_token_expires = expiration_date

        else:

            self.auth_token_expires = None

    def __str__(self):

        return self.name

    @property

    def resources(self):

        return self.resource_set.all()

    @resources.setter

    def resources(self, resources):

        for s in resources:

            self.resource_set.create(**s)

class ResourceMetadata(models.Model):

    key = models.CharField(_('Name'), max_length=255, unique=True, db_index=True)

    value = models.CharField(_('Value'), max_length=255)

_presentation_data = {}

def get_presentation(resource):

    global _presentation_data

    presentation = _presentation_data.get(resource, {})

    if not presentation:

        resource_presentation = RESOURCES_PRESENTATION_DATA.get('resources', {})

        presentation = resource_presentation.get(resource, {})

        _presentation_data[resource] = presentation

    return presentation

class Resource(models.Model):

    name = models.CharField(_('Name'), max_length=255)

    meta = models.ManyToManyField(ResourceMetadata)

    service = models.ForeignKey(Service)

    desc = models.TextField(_('Description'), null=True)

    unit = models.CharField(_('Name'), null=True, max_length=255)

    group = models.CharField(_('Group'), null=True, max_length=255)

    uplimit = intDecimalField(default=0)

    class Meta:

        unique_together = ("service", "name")

    def __str__(self):

        return '%s%s%s' % (self.service, RESOURCE_SEPARATOR, self.name)

    def full_name(self):

        return str(self)

    @property

    def help_text(self):

        return get_presentation(str(self)).get('help_text', '')

    @property

    def help_text_input_each(self):

        return get_presentation(str(self)).get('help_text_input_each', '')

    @property

    def is_abbreviation(self):

        return get_presentation(str(self)).get('is_abbreviation', False)

    @property

    def report_desc(self):

        return get_presentation(str(self)).get('report_desc', '')

    @property

    def placeholder(self):

        return get_presentation(str(self)).get('placeholder', '')

    @property

    def verbose_name(self):

        return get_presentation(str(self)).get('verbose_name', '')

    @property

    def display_name(self):

        name = self.verbose_name

        if self.is_abbreviation:

            name = name.upper()

        return name

    @property

    def pluralized_display_name(self):

        if not self.unit:

            return '%ss' % self.display_name

        return self.display_name

def load_service_resources():

    ss = []

    rs = []

    counter = 0

    for service_name, data in sorted(SERVICES.iteritems()):

        url = data.get('url')

        order = data.get('order', counter)

        counter = order + 1

        resources = data.get('resources') or ()

        service, created = Service.objects.get_or_create(

            name=service_name,

            defaults={'url': url, 'order': order}

        )

        if not created and url is not None:

            service.url = url

            service.save()

        ss.append(service)

        for resource in resources:

            try:

                resource_name = resource.pop('name', '')

                r, created = Resource.objects.get_or_create(

                        service=service, name=resource_name,

                        defaults=resource)

                if not created:

                    r.desc = resource['desc']

                    r.unit = resource.get('unit', None)

                    r.group = resource['group']

                    r.uplimit = resource['uplimit']

                    r.save()

                rs.append(r)

            except Exception, e:

                print "Cannot create resource ", resource_name

                import traceback; traceback.print_exc()

                continue

    register_resources(rs)

def get_default_quota():

    _DEFAULT_QUOTA = {}

    resources = Resource.objects.select_related('service').all()

    for resource in resources:

        capacity = resource.uplimit

        _DEFAULT_QUOTA[resource.full_name()] = capacity

    return _DEFAULT_QUOTA

def get_resource_names():

    _RESOURCE_NAMES = []

    resources = Resource.objects.select_related('service').all()

    _RESOURCE_NAMES = [resource.full_name() for resource in resources]

    return _RESOURCE_NAMES

class AstakosUserManager(UserManager):

    def get_auth_provider_user(self, provider, **kwargs):

        """

        Retrieve AstakosUser instance associated with the specified third party

        id.

        """

        kwargs = dict(map(lambda x: ('auth_providers__%s' % x[0], x[1]),

                          kwargs.iteritems()))

        return self.get(auth_providers__module=provider, **kwargs)

    def get_by_email(self, email):

        return self.get(email=email)

    def get_by_identifier(self, email_or_username, **kwargs):

        try:

            return self.get(email__iexact=email_or_username, **kwargs)

        except AstakosUser.DoesNotExist:

            return self.get(username__iexact=email_or_username, **kwargs)

    def user_exists(self, email_or_username, **kwargs):

        qemail = Q(email__iexact=email_or_username)

        qusername = Q(username__iexact=email_or_username)

        qextra = Q(**kwargs)

        return self.filter((qemail | qusername) & qextra).exists()

    def verified_user_exists(self, email_or_username):

        return self.user_exists(email_or_username, email_verified=True)

    def verified(self):

        return self.filter(email_verified=True)

    def uuid_catalog(self, l=None):

        """

        Returns a uuid to username mapping for the uuids appearing in l.

        If l is None returns the mapping for all existing users.

        """

        q = self.filter(uuid__in=l) if l != None else self

        return dict(q.values_list('uuid', 'username'))

    def displayname_catalog(self, l=None):

        """

        Returns a username to uuid mapping for the usernames appearing in l.

        If l is None returns the mapping for all existing users.

        """

        if l is not None:

            lmap = dict((x.lower(), x) for x in l)

            q = self.filter(username__in=lmap.keys())

            values = ((lmap[n], u) for n, u in q.values_list('username', 'uuid'))

        else:

            q = self

            values = self.values_list('username', 'uuid')

        return dict(values)

class AstakosUser(User):

    """

    Extends ``django.contrib.auth.models.User`` by defining additional fields.

    """

    affiliation = models.CharField(_('Affiliation'), max_length=255, blank=True,

                                   null=True)

    # DEPRECATED FIELDS: provider, third_party_identifier moved in

    #                    AstakosUserProvider model.

    provider = models.CharField(_('Provider'), max_length=255, blank=True,

                                null=True)

    # ex. screen_name for twitter, eppn for shibboleth

    third_party_identifier = models.CharField(_('Third-party identifier'),

                                              max_length=255, null=True,

                                              blank=True)

    #for invitations

    user_level = DEFAULT_USER_LEVEL

    level = models.IntegerField(_('Inviter level'), default=user_level)

    invitations = models.IntegerField(

        _('Invitations left'), default=INVITATIONS_PER_LEVEL.get(user_level, 0))

    auth_token = models.CharField(_('Authentication Token'),

                                  max_length=32,

                                  null=True,

                                  blank=True,

                                  help_text = _('Renew your authentication '

                                                'token. Make sure to set the new '

                                                'token in any client you may be '

                                                'using, to preserve its '

                                                'functionality.'))

    auth_token_created = models.DateTimeField(_('Token creation date'),

                                              null=True)

    auth_token_expires = models.DateTimeField(

        _('Token expiration date'), null=True)

    updated = models.DateTimeField(_('Update date'))

    is_verified = models.BooleanField(_('Is verified?'), default=False)

    email_verified = models.BooleanField(_('Email verified?'), default=False)

    has_credits = models.BooleanField(_('Has credits?'), default=False)

    has_signed_terms = models.BooleanField(

        _('I agree with the terms'), default=False)

    date_signed_terms = models.DateTimeField(

        _('Signed terms date'), null=True, blank=True)

    activation_sent = models.DateTimeField(

        _('Activation sent data'), null=True, blank=True)

    policy = models.ManyToManyField(

        Resource, null=True, through='AstakosUserQuota')

    uuid = models.CharField(max_length=255, null=True, blank=False, unique=True)

    __has_signed_terms = False

    disturbed_quota = models.BooleanField(_('Needs quotaholder syncing'),

                                           default=False, db_index=True)

    objects = AstakosUserManager()

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

        super(AstakosUser, self).__init__(*args, **kwargs)

        self.__has_signed_terms = self.has_signed_terms

        if not self.id:

            self.is_active = False

    @property

    def realname(self):

        return '%s %s' % (self.first_name, self.last_name)

    @property

    def log_display(self):

        """

        Should be used in all logger.* calls that refer to a user so that

        user display is consistent across log entries.

        """

        return '%s::%s' % (self.uuid, self.email)

    @realname.setter

    def realname(self, value):

        parts = value.split(' ')

        if len(parts) == 2:

            self.first_name = parts[0]

            self.last_name = parts[1]

        else:

            self.last_name = parts[0]

    def add_permission(self, pname):

        if self.has_perm(pname):

            return

        p, created = Permission.objects.get_or_create(

                                    codename=pname,

                                    name=pname.capitalize(),

                                    content_type=get_content_type())

        self.user_permissions.add(p)

    def remove_permission(self, pname):

        if self.has_perm(pname):

            return

        p = Permission.objects.get(codename=pname,

                                   content_type=get_content_type())

        self.user_permissions.remove(p)

    def is_project_admin(self, application_id=None):

        return self.uuid in PROJECT_ADMINS

    @property

    def invitation(self):

        try:

            return Invitation.objects.get(username=self.email)

        except Invitation.DoesNotExist:

            return None

    @property

    def policies(self):

        return self.astakosuserquota_set.select_related().all()

    @policies.setter

    def policies(self, policies):

        for p in policies:

            p.setdefault('resource', '')

            p.setdefault('capacity', 0)

            p.setdefault('quantity', 0)

            p.setdefault('update', True)

            self.add_resource_policy(**p)

    def add_resource_policy(

            self, resource, capacity,

            update=True):

        """Raises ObjectDoesNotExist, IntegrityError"""

        s, sep, r = resource.partition(RESOURCE_SEPARATOR)

        resource = Resource.objects.get(service__name=s, name=r)

        if update:

            AstakosUserQuota.objects.update_or_create(

                user=self, resource=resource, defaults={

                    'capacity':capacity,

                    })

        else:

            q = self.astakosuserquota_set

            q.create(

                resource=resource, capacity=capacity, quanity=quantity,

                )

    def get_resource_policy(self, resource):

        s, sep, r = resource.partition(RESOURCE_SEPARATOR)

        resource = Resource.objects.get(service__name=s, name=r)

        default_capacity = resource.uplimit

        try:

            policy = AstakosUserQuota.objects.get(user=self, resource=resource)

            return policy, default_capacity

        except AstakosUserQuota.DoesNotExist:

            return None, default_capacity

    def remove_resource_policy(self, service, resource):

        """Raises ObjectDoesNotExist, IntegrityError"""

        resource = Resource.objects.get(service__name=service, name=resource)

        q = self.policies.get(resource=resource).delete()

    def update_uuid(self):

        while not self.uuid:

            uuid_val =  str(uuid.uuid4())

            try:

                AstakosUser.objects.get(uuid=uuid_val)

            except AstakosUser.DoesNotExist, e:

                self.uuid = uuid_val

        return self.uuid

    def save(self, update_timestamps=True, **kwargs):

        if update_timestamps:

            if not self.id:

                self.date_joined = datetime.now()

            self.updated = datetime.now()

        # update date_signed_terms if necessary

        if self.__has_signed_terms != self.has_signed_terms:

            self.date_signed_terms = datetime.now()

        self.update_uuid()

        if self.username != self.email.lower():

            # set username

            self.username = self.email.lower()

        super(AstakosUser, self).save(**kwargs)

    def renew_token(self, flush_sessions=False, current_key=None):

        md5 = hashlib.md5()

        md5.update(settings.SECRET_KEY)

        md5.update(self.username)

        md5.update(self.realname.encode('ascii', 'ignore'))

        md5.update(asctime())

        self.auth_token = b64encode(md5.digest())

        self.auth_token_created = datetime.now()

        self.auth_token_expires = self.auth_token_created + \

                                  timedelta(hours=AUTH_TOKEN_DURATION)

        if flush_sessions:

            self.flush_sessions(current_key)

        msg = 'Token renewed for %s' % self.email

        logger.log(LOGGING_LEVEL, msg)

    def flush_sessions(self, current_key=None):

        q = self.sessions

        if current_key:

            q = q.exclude(session_key=current_key)

        keys = q.values_list('session_key', flat=True)

        if keys:

            msg = 'Flushing sessions: %s' % ','.join(keys)

            logger.log(LOGGING_LEVEL, msg, [])

        engine = import_module(settings.SESSION_ENGINE)

        for k in keys:

            s = engine.SessionStore(k)

            s.flush()

    def __unicode__(self):

        return '%s (%s)' % (self.realname, self.email)

    def conflicting_email(self):

        q = AstakosUser.objects.exclude(username=self.username)

        q = q.filter(email__iexact=self.email)

        if q.count() != 0:

            return True

        return False

    def email_change_is_pending(self):

        return self.emailchanges.count() > 0

    @property

    def signed_terms(self):

        term = get_latest_terms()

        if not term:

            return True

        if not self.has_signed_terms:

            return False

        if not self.date_signed_terms:

            return False

        if self.date_signed_terms < term.date:

            self.has_signed_terms = False

            self.date_signed_terms = None

            self.save()

            return False

        return True

    def set_invitations_level(self):

        """

        Update user invitation level

        """

        level = self.invitation.inviter.level + 1

        self.level = level

        self.invitations = INVITATIONS_PER_LEVEL.get(level, 0)

    def can_change_password(self):

        return self.has_auth_provider('local', auth_backend='astakos')

    def can_change_email(self):

        if not self.has_auth_provider('local'):

            return True

        local = self.get_auth_provider('local')._instance

        return local.auth_backend == 'astakos'

    # Auth providers related methods

    def get_auth_provider(self, module=None, identifier=None, **filters):

        if not module:

            return self.auth_providers.active()[0].settings

        params = {'module': module}

        if identifier:

            params['identifier'] = identifier

        params.update(filters)

        return self.auth_providers.active().get(**params).settings

    def has_auth_provider(self, provider, **kwargs):

        return bool(self.auth_providers.active().filter(module=provider,

                                                        **kwargs).count())

    def get_required_providers(self, **kwargs):

        return auth.REQUIRED_PROVIDERS.keys()

    def missing_required_providers(self):

        required = self.get_required_providers()

        missing = []

        for provider in required:

            if not self.has_auth_provider(provider):

                missing.append(auth.get_provider(provider, self))

        return missing

    def get_available_auth_providers(self, **filters):

        """

        Returns a list of providers available for add by the user.

        """

        modules = astakos_settings.IM_MODULES

        providers = []

        for p in modules:

            providers.append(auth.get_provider(p, self))

        available = []

        for p in providers:

            if p.get_add_policy:

                available.append(p)

        return available

    def get_disabled_auth_providers(self, **filters):

        providers = self.get_auth_providers(**filters)

        disabled = []

        for p in providers:

            if not p.get_login_policy:

                disabled.append(p)

        return disabled

    def get_enabled_auth_providers(self, **filters):

        providers = self.get_auth_providers(**filters)

        enabled = []

        for p in providers:

            if p.get_login_policy:

                enabled.append(p)

        return enabled

    def get_auth_providers(self, **filters):

        providers = []

        for provider in self.auth_providers.active(**filters):

            if provider.settings.module_enabled:

                providers.append(provider.settings)

        modules = astakos_settings.IM_MODULES

        def key(p):

            if not p.module in modules:

                return 100

            return modules.index(p.module)

        providers = sorted(providers, key=key)

        return providers

    # URL methods

    @property

    def auth_providers_display(self):

        return ",".join(["%s:%s" % (p.module, p.get_username_msg) for p in

                         self.get_enabled_auth_providers()])

    def add_auth_provider(self, module='local', identifier=None, **params):

        provider = auth.get_provider(module, self, identifier, **params)

        provider.add_to_user()

    def get_resend_activation_url(self):

        return reverse('send_activation', kwargs={'user_id': self.pk})

    def get_activation_url(self, nxt=False):

        url = "%s?auth=%s" % (reverse('astakos.im.views.activate'),

                                 quote(self.auth_token))

        if nxt:

            url += "&next=%s" % quote(nxt)

        return url

    def get_password_reset_url(self, token_generator=default_token_generator):

        return reverse('django.contrib.auth.views.password_reset_confirm',

                          kwargs={'uidb36':int_to_base36(self.id),

                                  'token':token_generator.make_token(self)})

    def get_inactive_message(self, provider_module, identifier=None):

        provider = self.get_auth_provider(provider_module, identifier)

        msg_extra = ''

        message = ''

        msg_inactive = provider.get_account_inactive_msg

        msg_pending = provider.get_pending_activation_msg

        msg_pending_help = _(astakos_messages.ACCOUNT_PENDING_ACTIVATION_HELP)

        #msg_resend_prompt = _(astakos_messages.ACCOUNT_RESEND_ACTIVATION)

        msg_pending_mod = provider.get_pending_moderation_msg

        msg_resend = _(astakos_messages.ACCOUNT_RESEND_ACTIVATION)

        if self.activation_sent:

            if self.email_verified:

                message = msg_inactive

            else:

                message = msg_pending

                url = self.get_resend_activation_url()

                msg_extra = msg_pending_help + \

                            u' ' + \

                            '<a href="%s">%s?</a>' % (url, msg_resend)

        else:

            if astakos_settings.MODERATION_ENABLED:

                message = msg_pending_mod

            else:

                message = msg_pending

                url = self.get_resend_activation_url()

                msg_extra = '<a href="%s">%s?</a>' % (url, \

                                msg_resend)

        return mark_safe(message + u' '+ msg_extra)

    def owns_application(self, application):

        return application.owner == self

    def owns_project(self, project):

        return project.application.owner == self

    def is_associated(self, project):

        try:

            m = ProjectMembership.objects.get(person=self, project=project)

            return m.state in ProjectMembership.ASSOCIATED_STATES

        except ProjectMembership.DoesNotExist:

            return False

    def get_membership(self, project):

        try:

            return ProjectMembership.objects.get(

                project=project,

                person=self)

        except ProjectMembership.DoesNotExist:

            return None

    def membership_display(self, project):

        m = self.get_membership(project)

        if m is None:

            return _('Not a member')

        else:

            return m.user_friendly_state_display()

    def non_owner_can_view(self, maybe_project):

        if self.is_project_admin():

            return True

        if maybe_project is None:

            return False

        project = maybe_project

        if self.is_associated(project):

            return True

        if project.is_deactivated():

            return False

        return True

    def settings(self):

        return UserSetting.objects.filter(user=self)

    def all_quotas(self):

        quotas = users_quotas([self])

        try:

            return quotas[self.uuid]

        except:

            raise ValueError("could not compute quotas")

def initial_quotas(users):

    initial = {}

    default_quotas = get_default_quota()

    for user in users:

        uuid = user.uuid

        initial[uuid] = dict(default_quotas)

    objs = AstakosUserQuota.objects.select_related()

    orig_quotas = objs.filter(user__in=users)

    for user_quota in orig_quotas:

        uuid = user_quota.user.uuid

        user_init = initial.get(uuid, {})

        resource = user_quota.resource.full_name()

        user_init[resource] = user_quota.capacity

        initial[uuid] = user_init

    return initial

def users_quotas(users, initial=None):

    if initial is None:

        quotas = initial_quotas(users)

    else:

        quotas = copy.deepcopy(initial)

    objs = ProjectMembership.objects.select_related('application', 'person')

    memberships = objs.filter(person__in=users)

    apps = set(m.application for m in memberships if m.application is not None)

    objs = ProjectResourceGrant.objects.select_related()

    grants = objs.filter(project_application__in=apps)

    for membership in memberships:

        uuid = membership.person.uuid

        userquotas = quotas.get(uuid, {})

        application = membership.application

        if application is None:

            continue

        for grant in grants:

            if grant.project_application_id != application.id:

                continue

            resource = grant.resource.full_name()

            prev = userquotas.get(resource, 0)

            new = prev + grant.member_capacity

            userquotas[resource] = new

        quotas[uuid] = userquotas

    return quotas

class AstakosUserAuthProviderManager(models.Manager):

    def active(self, **filters):

        return self.filter(active=True, **filters)

    def remove_unverified_providers(self, provider, **filters):

        try:

            existing = self.filter(module=provider, user__email_verified=False,

                                   **filters)

            for p in existing:

                p.user.delete()

        except:

            pass

    def unverified(self, provider, **filters):

        try:

            return self.get(module=provider, user__email_verified=False,

                            **filters).settings

        except AstakosUserAuthProvider.DoesNotExist:

            return None

    def verified(self, provider, **filters):

        try:

            return self.get(module=provider, user__email_verified=True,

                            **filters).settings

        except AstakosUserAuthProvider.DoesNotExist:

            return None

class AuthProviderPolicyProfileManager(models.Manager):

    def active(self):

        return self.filter(active=True)

    def for_user(self, user, provider):

        policies = {}

        exclusive_q1 = Q(provider=provider) & Q(is_exclusive=False)

        exclusive_q2 = ~Q(provider=provider) & Q(is_exclusive=True)

        exclusive_q = exclusive_q1 | exclusive_q2

        for profile in user.authpolicy_profiles.active().filter(exclusive_q):

            policies.update(profile.policies)

        user_groups = user.groups.all().values('pk')

        for profile in self.active().filter(groups__in=user_groups).filter(

                exclusive_q):

            policies.update(profile.policies)

        return policies

    def add_policy(self, name, provider, group_or_user, exclusive=False,

                   **policies):

        is_group = isinstance(group_or_user, Group)

        profile, created = self.get_or_create(name=name, provider=provider,

                                              is_exclusive=exclusive)

        profile.is_exclusive = exclusive

        profile.save()

        if is_group:

            profile.groups.add(group_or_user)

        else:

            profile.users.add(group_or_user)

        profile.set_policies(policies)

        profile.save()

        return profile

class AuthProviderPolicyProfile(models.Model):

    name = models.CharField(_('Name'), max_length=255, blank=False,

                            null=False, db_index=True)

    provider = models.CharField(_('Provider'), max_length=255, blank=False,

                                null=False)

    # apply policies to all providers excluding the one set in provider field

    is_exclusive = models.BooleanField(default=False)

    policy_add = models.NullBooleanField(null=True, default=None)

    policy_remove = models.NullBooleanField(null=True, default=None)

    policy_create = models.NullBooleanField(null=True, default=None)

    policy_login = models.NullBooleanField(null=True, default=None)

    policy_limit = models.IntegerField(null=True, default=None)

    policy_required = models.NullBooleanField(null=True, default=None)

    policy_automoderate = models.NullBooleanField(null=True, default=None)

    policy_switch = models.NullBooleanField(null=True, default=None)

    POLICY_FIELDS = ('add', 'remove', 'create', 'login', 'limit', 'required',

                     'automoderate')

    priority = models.IntegerField(null=False, default=1)

    groups = models.ManyToManyField(Group, related_name='authpolicy_profiles')

    users = models.ManyToManyField(AstakosUser,

                                   related_name='authpolicy_profiles')

    active = models.BooleanField(default=True)

    objects = AuthProviderPolicyProfileManager()

    class Meta:

        ordering = ['priority']

    @property

    def policies(self):

        policies = {}

        for pkey in self.POLICY_FIELDS:

            value = getattr(self, 'policy_%s' % pkey, None)

            if value is None:

                continue

            policies[pkey] = value

        return policies

    def set_policies(self, policies_dict):

        for key, value in policies_dict.iteritems():

            if key in self.POLICY_FIELDS:

                setattr(self, 'policy_%s' % key, value)

        return self.policies

class AstakosUserAuthProvider(models.Model):

    """

    Available user authentication methods.

    """

    affiliation = models.CharField(_('Affiliation'), max_length=255, blank=True,

                                   null=True, default=None)

    user = models.ForeignKey(AstakosUser, related_name='auth_providers')

    module = models.CharField(_('Provider'), max_length=255, blank=False,

                                default='local')

    identifier = models.CharField(_('Third-party identifier'),

                                              max_length=255, null=True,

                                              blank=True)

    active = models.BooleanField(default=True)

    auth_backend = models.CharField(_('Backend'), max_length=255, blank=False,

                                   default='astakos')

    info_data = models.TextField(default="", null=True, blank=True)

    created = models.DateTimeField('Creation date', auto_now_add=True)

    objects = AstakosUserAuthProviderManager()

    class Meta:

        unique_together = (('identifier', 'module', 'user'), )

        ordering = ('module', 'created')

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

        super(AstakosUserAuthProvider, self).__init__(*args, **kwargs)

        try:

            self.info = json.loads(self.info_data)

            if not self.info:

                self.info = {}

        except Exception, e:

            self.info = {}

        for key,value in self.info.iteritems():

            setattr(self, 'info_%s' % key, value)

    @property

    def settings(self):

        extra_data = {}

        info_data = {}

        if self.info_data:

            info_data = json.loads(self.info_data)

        extra_data['info'] = info_data

        for key in ['active', 'auth_backend', 'created', 'pk', 'affiliation']:

            extra_data[key] = getattr(self, key)

        extra_data['instance'] = self

        return auth.get_provider(self.module, self.user,

                                           self.identifier, **extra_data)

    def __repr__(self):

        return '<AstakosUserAuthProvider %s:%s>' % (self.module, self.identifier)

    def __unicode__(self):

        if self.identifier:

            return "%s:%s" % (self.module, self.identifier)

        if self.auth_backend:

            return "%s:%s" % (self.module, self.auth_backend)

        return self.module

    def save(self, *args, **kwargs):

        self.info_data = json.dumps(self.info)

        return super(AstakosUserAuthProvider, self).save(*args, **kwargs)

class ExtendedManager(models.Manager):

    def _update_or_create(self, **kwargs):

        assert kwargs, \

            'update_or_create() must be passed at least one keyword argument'

        obj, created = self.get_or_create(**kwargs)

        defaults = kwargs.pop('defaults', {})

        if created:

            return obj, True, False

        else:

            try:

                params = dict(

                    [(k, v) for k, v in kwargs.items() if '__' not in k])

                params.update(defaults)

                for attr, val in params.items():

                    if hasattr(obj, attr):

                        setattr(obj, attr, val)

                sid = transaction.savepoint()

                obj.save(force_update=True)

                transaction.savepoint_commit(sid)

                return obj, False, True

            except IntegrityError, e:

                transaction.savepoint_rollback(sid)

                try:

                    return self.get(**kwargs), False, False

                except self.model.DoesNotExist:

                    raise e

    update_or_create = _update_or_create

class AstakosUserQuota(models.Model):

    objects = ExtendedManager()

    capacity = intDecimalField()

    quantity = intDecimalField(default=0)

    export_limit = intDecimalField(default=QH_PRACTICALLY_INFINITE)

    import_limit = intDecimalField(default=QH_PRACTICALLY_INFINITE)

    resource = models.ForeignKey(Resource)

    user = models.ForeignKey(AstakosUser)

    class Meta:

        unique_together = ("resource", "user")

class ApprovalTerms(models.Model):

    """

    Model for approval terms

    """

    date = models.DateTimeField(

        _('Issue date'), db_index=True, auto_now_add=True)

    location = models.CharField(_('Terms location'), max_length=255)

class Invitation(models.Model):

    """

    Model for registring invitations

    """

    inviter = models.ForeignKey(AstakosUser, related_name='invitations_sent',

                                null=True)

    realname = models.CharField(_('Real name'), max_length=255)

    username = models.CharField(_('Unique ID'), max_length=255, unique=True)

    code = models.BigIntegerField(_('Invitation code'), db_index=True)

    is_consumed = models.BooleanField(_('Consumed?'), default=False)

    created = models.DateTimeField(_('Creation date'), auto_now_add=True)

    consumed = models.DateTimeField(_('Consumption date'), null=True, blank=True)

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

        super(Invitation, self).__init__(*args, **kwargs)

        if not self.id:

            self.code = _generate_invitation_code()

    def consume(self):

        self.is_consumed = True

        self.consumed = datetime.now()

        self.save()

    def __unicode__(self):

        return '%s -> %s [%d]' % (self.inviter, self.username, self.code)

class EmailChangeManager(models.Manager):

    @transaction.commit_on_success

    def change_email(self, activation_key):

        """

        Validate an activation key and change the corresponding

        ``User`` if valid.

        If the key is valid and has not expired, return the ``User``

        after activating.

        If the key is not valid or has expired, return ``None``.

        If the key is valid but the ``User`` is already active,