Synnefo

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

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import hashlib

import uuid

import logging

import json

from time import asctime

from datetime import datetime, timedelta

from base64 import b64encode

from urlparse import urlparse, urlunparse

from random import randint

from collections import defaultdict

from south.signals import post_migrate

from django.db import models, IntegrityError

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

from django.utils.translation import ugettext as _

from django.core.exceptions import ValidationError

from django.template.loader import render_to_string

from django.core.mail import send_mail

from django.db import transaction

from django.db.models.signals import post_save, post_syncdb

from django.db.models import Q, Count

from astakos.im.settings import DEFAULT_USER_LEVEL, INVITATIONS_PER_LEVEL, \

    AUTH_TOKEN_DURATION, BILLING_FIELDS, QUEUE_CONNECTION, SITENAME, \

    EMAILCHANGE_ACTIVATION_DAYS, LOGGING_LEVEL

QUEUE_CLIENT_ID = 3 # Astakos.

logger = logging.getLogger(__name__)

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)

    def save(self, **kwargs):

        if not self.id:

            self.renew_token()

        self.full_clean()

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

    def renew_token(self):

        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()

        self.auth_token_expires = self.auth_token_created + \

                                  timedelta(hours=AUTH_TOKEN_DURATION)

    def __str__(self):

        return self.name

class ResourceMetadata(models.Model):

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

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

class Resource(models.Model):

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

    meta = models.ManyToManyField(ResourceMetadata)

    service = models.ForeignKey(Service)

    def __str__(self):

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

class GroupKind(models.Model):

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

    def __str__(self):

        return self.name

class AstakosGroup(Group):

    kind = models.ForeignKey(GroupKind)

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

    policy = models.ManyToManyField(Resource, null=True, blank=True, through='AstakosGroupQuota')

    creation_date = models.DateTimeField('Creation date', default=datetime.now())

    issue_date = models.DateTimeField('Issue date', null=True)

    expiration_date = models.DateTimeField('Expiration date', null=True)

    moderation_enabled = models.BooleanField('Moderated membership?', default=True)

    approval_date = models.DateTimeField('Activation date', null=True, blank=True)

    estimated_participants = models.PositiveIntegerField('Estimated #participants', null=True)

    @property

    def is_disabled(self):

        if not self.approval_date:

            return True

        return False

    @property

    def is_enabled(self):

        if self.is_disabled:

            return False

        if not self.issue_date:

            return False

        if not self.expiration_date:

            return True

        now = datetime.now()

        if self.issue_date > now:

            return False

        if now >= self.expiration_date:

            return False

        return True

    @property

    def participants(self):

        return len(self.approved_members)

    def enable(self):

        self.approval_date = datetime.now()

        self.save()

    def disable(self):

        self.approval_date = None

        self.save()

    def approve_member(self, person):

        try:

            self.membership_set.create(person=person, date_joined=datetime.now())

        except IntegrityError:

            m = self.membership_set.get(person=person)

            m.date_joined = datetime.now()

            m.save()

    def disapprove_member(self, person):

        self.membership_set.remove(person=person)

    @property

    def members(self):

        return map(lambda m:m.person, self.membership_set.all())

    @property

    def approved_members(self):

        f = filter(lambda m:m.is_approved, self.membership_set.all())

        return map(lambda m:m.person, f)

    @property

    def quota(self):

        d = {}

        for q in  self.astakosgroupquota_set.all():

            d[q.resource.name] = q.limit

        return d

    @property

    def has_undefined_policies(self):

        # TODO: can avoid query?

        return Resource.objects.filter(~Q(astakosgroup=self)).exists()

class AstakosUser(User):

    """

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

    """

    # Use UserManager to get the create_user method, etc.

    objects = UserManager()

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

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

    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)

    # ex. screen_name for twitter, eppn for shibboleth

    third_party_identifier = models.CharField('Third-party identifier', max_length=255, null=True, blank=True)

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

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

    has_signed_terms = models.BooleanField('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')

    astakos_groups = models.ManyToManyField(AstakosGroup, verbose_name=_('agroups'), blank=True,

        help_text=_("In addition to the permissions manually assigned, this user will also get all permissions granted to each group he/she is in."),

        through='Membership')

    __has_signed_terms = False

    __groupnames = []

    owner = models.ManyToManyField(AstakosGroup, related_name='owner', null=True)

    class Meta:

        unique_together = ("provider", "third_party_identifier")

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

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

        self.__has_signed_terms = self.has_signed_terms

        if self.id:

            self.__groupnames = [g.name for g in self.astakos_groups.all()]

        else:

            self.is_active = False

    @property

    def realname(self):

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

    @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]

    @property

    def invitation(self):

        try:

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

        except Invitation.DoesNotExist:

            return None

    @property

    def quota(self):

        d = defaultdict(int)

        for q in  self.astakosuserquota_set.all():

            d[q.resource.name] += q.limit

        for g in self.astakos_groups.all():

            if not g.is_enabled:

                continue

            for r, limit in g.quota.iteritems():

                d[r] += limit

        # TODO set default for remaining

        return d

    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()

        if not self.id:

            # set username

            while not self.username:

                username =  uuid.uuid4().hex[:30]

                try:

                    AstakosUser.objects.get(username = username)

                except AstakosUser.DoesNotExist, e:

                    self.username = username

            if not self.provider:

                self.provider = 'local'

        report_user_event(self)

        self.validate_unique_email_isactive()

        if self.is_active and self.activation_sent:

            # reset the activation sent

            self.activation_sent = None

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

        # set group if does not exist

        groupname = 'shibboleth' if self.provider == 'shibboleth' else 'default'

        if groupname not in self.__groupnames:

            try:

                group = AstakosGroup.objects.get(name = groupname)

                Membership(group=group, person=self, date_joined=datetime.now()).save()

            except AstakosGroup.DoesNotExist, e:

                logger.exception(e)

    def renew_token(self):

        md5 = hashlib.md5()

        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)

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

        logger._log(LOGGING_LEVEL, msg, [])

    def __unicode__(self):

        return self.username

    def conflicting_email(self):

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

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

        if q.count() != 0:

            return True

        return False

    def validate_unique_email_isactive(self):

        """

        Implements a unique_together constraint for email and is_active fields.

        """

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

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

        q = q.filter(is_active = self.is_active)

        if q.count() != 0:

            raise ValidationError({'__all__':[_('Another account with the same email & is_active combination found.')]})

    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

class Membership(models.Model):

    person = models.ForeignKey(AstakosUser)

    group = models.ForeignKey(AstakosGroup)

    date_requested = models.DateField(default=datetime.now(), blank=True)

    date_joined = models.DateField(null=True, db_index=True, blank=True)

    class Meta:

        unique_together = ("person", "group")

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

        if not self.id:

            if not self.group.moderation_enabled:

                self.date_joined = datetime.now()

        super(Membership, self).save(*args, **kwargs)

    @property

    def is_approved(self):

        if self.date_joined:

            return True

        return False

    def approve(self):

        self.date_joined = datetime.now()

        self.save()

    def disapprove(self):

        self.delete()

class AstakosGroupQuota(models.Model):

    limit = models.PositiveIntegerField('Limit')

    resource = models.ForeignKey(Resource)

    group = models.ForeignKey(AstakosGroup, blank=True)

    class Meta:

        unique_together = ("resource", "group")

class AstakosUserQuota(models.Model):

    limit = models.PositiveIntegerField('Limit')

    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, default=datetime.now())

    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)

def report_user_event(user):

    def should_send(user):

        # report event incase of new user instance

        # or if specific fields are modified

        if not user.id:

            return True

        try:

            db_instance = AstakosUser.objects.get(id = user.id)

        except AstakosUser.DoesNotExist:

            return True

        for f in BILLING_FIELDS:

            if (db_instance.__getattribute__(f) != user.__getattribute__(f)):

                return True

        return False

    if QUEUE_CONNECTION and should_send(user):

        from astakos.im.queue.userevent import UserEvent

        from synnefo.lib.queue import exchange_connect, exchange_send, \

                exchange_close

        eventType = 'create' if not user.id else 'modify'

        body = UserEvent(QUEUE_CLIENT_ID, user, eventType, {}).format()

        conn = exchange_connect(QUEUE_CONNECTION)

        parts = urlparse(QUEUE_CONNECTION)

        exchange = parts.path[1:]

        routing_key = '%s.user' % exchange

        exchange_send(conn, routing_key, body)

        exchange_close(conn)

def _generate_invitation_code():

    while True:

        code = randint(1, 2L**63 - 1)

        try:

            Invitation.objects.get(code=code)

            # An invitation with this code already exists, try again

        except Invitation.DoesNotExist:

            return code

def get_latest_terms():

    try:

        term = ApprovalTerms.objects.order_by('-id')[0]

        return term

    except IndexError:

        pass

    return None

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,

        return ``None``.

        After successful email change the activation record is deleted.

        Throws ValueError if there is already

        """

        try:

            email_change = self.model.objects.get(activation_key=activation_key)

            if email_change.activation_key_expired():

                email_change.delete()

                raise EmailChange.DoesNotExist

            # is there an active user with this address?

            try:

                AstakosUser.objects.get(email=email_change.new_email_address)

            except AstakosUser.DoesNotExist:

                pass

            else:

                raise ValueError(_('The new email address is reserved.'))

            # update user

            user = AstakosUser.objects.get(pk=email_change.user_id)

            user.email = email_change.new_email_address

            user.save()

            email_change.delete()

            return user

        except EmailChange.DoesNotExist:

            raise ValueError(_('Invalid activation key'))

class EmailChange(models.Model):

    new_email_address = models.EmailField(_(u'new e-mail address'), help_text=_(u'Your old email address will be used until you verify your new one.'))

    user = models.ForeignKey(AstakosUser, unique=True, related_name='emailchange_user')

    requested_at = models.DateTimeField(default=datetime.now())

    activation_key = models.CharField(max_length=40, unique=True, db_index=True)

    objects = EmailChangeManager()

    def activation_key_expired(self):

        expiration_date = timedelta(days=EMAILCHANGE_ACTIVATION_DAYS)

        return self.requested_at + expiration_date < datetime.now()

class AdditionalMail(models.Model):

    """

    Model for registring invitations

    """

    owner = models.ForeignKey(AstakosUser)

    email = models.EmailField()

def create_astakos_user(u):

    try:

        AstakosUser.objects.get(user_ptr=u.pk)

    except AstakosUser.DoesNotExist:

        extended_user = AstakosUser(user_ptr_id=u.pk)

        extended_user.__dict__.update(u.__dict__)

        extended_user.renew_token()

        extended_user.save()

    except:

        pass

def superuser_post_syncdb(sender, **kwargs):

    # if there was created a superuser

    # associate it with an AstakosUser

    admins = User.objects.filter(is_superuser=True)

    for u in admins:

        create_astakos_user(u)

post_syncdb.connect(superuser_post_syncdb)

def superuser_post_save(sender, instance, **kwargs):

    if instance.is_superuser:

        create_astakos_user(instance)

post_save.connect(superuser_post_save, sender=User)