Synnefo

# vim: set fileencoding=utf-8 :

# 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 THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS 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.

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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.

from datetime import timedelta

import base64

import time

import urllib

from django.conf import settings

from django.core.exceptions import ValidationError

from django.db import transaction

from django.http import HttpResponse, HttpResponseRedirect

from django.template.context import RequestContext

from django.template.loader import render_to_string

from django.core.validators import validate_email

from django.views.decorators.csrf import csrf_protect

from synnefo.logic.email_send import send_async

from synnefo.api.common import method_not_allowed

from synnefo.db.models import Invitations, SynnefoUser

from synnefo.logic import users

from Crypto.Cipher import AES

def process_form(request):

    errors = []

    valid_inv = filter(lambda x: x.startswith("name_"), request.POST.keys())

    for inv in valid_inv:

        (name, inv_id) = inv.split('_')

        email = ""

        name = ""

        try:

            email = request.POST['email_' + inv_id]

            name = request.POST[inv]

            validate_name(name)

            validate_email(email)

            inv = add_invitation(request.user, name, email)

            send_invitation(inv)

        except Exception as e:

            try :

                errors += ["Invitation to %s <%s> not sent. Reason: %s" %

                           (name, email, e.messages[0])]

            except:

                errors += ["Invitation to %s <%s> not sent. Reason: %s" %

                           (name, email, e.message)]

    respose = None

    if errors:

        data = render_to_string('invitations.html',

                                {'invitations': invitations_for_user(request),

                                 'errors': errors},

                                context_instance=RequestContext(request))

        response =  HttpResponse(data)

    else:

        response = HttpResponseRedirect("/invitations/")

    return response

def validate_name(name):

    if name is None or name.strip() == '' :

        raise ValidationError("Name is empty")

    if name.find(' ') is -1:

        raise ValidationError("Name must contain at least one space")

    return True

def invitations_for_user(request):

    invitations = []

    for inv in Invitations.objects.filter(source = request.user):

        invitation = {}

        invitation['sourcename'] = inv.source.realname

        invitation['source'] = inv.source.uniq

        invitation['targetname'] = inv.target.realname

        invitation['target'] = inv.target.uniq

        invitation['accepted'] = inv.accepted

        invitation['sent'] = inv.created

        invitations.append(invitation)

    return invitations

@csrf_protect

def inv_demux(request):

    if request.method == 'GET':

        data = render_to_string('invitations.html',

                                {'invitations': invitations_for_user(request)},

                                context_instance=RequestContext(request))

        return  HttpResponse(data)

    elif request.method == 'POST':

        return process_form(request)

    else:

        method_not_allowed(request)

def login(request):

    if not request.method == 'GET':

        method_not_allowed(request)

    key = request.GET['key']

    if key is None:

        return render_login_error("10", "Required key is missing")

    PADDING = '{'

    try :

        DecodeAES = lambda c, e: c.decrypt(base64.b64decode(e)).rstrip(PADDING)

        cipher = AES.new(settings.INVITATION_ENCR_KEY)

        decoded = DecodeAES(cipher, key)

    except Exception:

        return render_login_error("20", "Required key is invalid")

    users = SynnefoUser.objects.filter(auth_token = decoded)

    if users.count() is 0:

        return render_login_error("20", "Required key is invalid")

    user = users[0]

    invitations = Invitations.objects.filter(target = user)

    if invitations.count() is 0:

        return render_login_error("30", "Non-existent invitation")

    inv = invitations[0]

    valid = timedelta(days = settings.INVITATION_VALID_DAYS)

    valid_until = inv.created + valid

    if (time.time() -

        time.mktime(inv.created.timetuple()) -

        settings.INVITATION_VALID_DAYS * 3600) > 0:

        return render_login_error("40",

                                  "Invitation expired (was valid until %s)"%

                                  valid_until.strftime('%A, %d %B %Y'))

    #if inv.accepted == False:

    #    return render_login_error("60", "Invitation already accepted")

    inv.accepted = True

    inv.save()

    data = dict()

    data['user'] = user.realname

    data['url'] = settings.APP_INSTALL_URL

    welcome = render_to_string('welcome.html', {'data': data})

    response = HttpResponse(welcome)

    response.set_cookie('X-Auth-Token', value=user.auth_token,

                        expires = valid_until.strftime('%a, %d-%b-%Y %H:%M:%S %Z'),

                        path='/')

    response['X-Auth-Token'] = user.auth_token

    return response

def render_login_error(code, text):

    error = dict()

    error['id'] = code

    error['text'] = text

    data = render_to_string('error.html', {'error': error})

    response = HttpResponse(data)

    return response

def send_invitation(invitation):

    email = {}

    email['invitee'] = invitation.target.realname

    email['inviter'] = invitation.source.realname

    valid = timedelta(days = settings.INVITATION_VALID_DAYS)

    valid_until = invitation.created + valid

    email['valid_until'] = valid_until.strftime('%A, %d %B %Y')

    PADDING = '{'

    pad = lambda s: s + (32 - len(s) % 32) * PADDING

    EncodeAES = lambda c, s: base64.b64encode(c.encrypt(pad(s)))

    cipher = AES.new(settings.INVITATION_ENCR_KEY)

    encoded = EncodeAES(cipher, invitation.target.auth_token)

    url_safe = urllib.urlencode({'key': encoded})

    email['url'] = settings.APP_INSTALL_URL + "/invitations/login?" + url_safe

    data = render_to_string('invitation.txt', {'email': email})

    print data

    send_async(

        frm = "%s <%s>"%(invitation.source.realname,invitation.source.uniq),

        to = "%s <%s>"%(invitation.target.realname,invitation.target.uniq),

        subject = u'Πρόσκληση για την υπηρεσία Ωκεανός',

        body = data

    )

def get_invitee_level(source):

    return get_user_inv_level(source) + 1

def get_user_inv_level(u):

    inv = Invitations.objects.filter(target = u)

    if inv is None:

        raise Exception("User without invitation", u)

    return inv[0].level

@transaction.commit_on_success

def add_invitation(source, name, email):

    """

        Adds an invitation, if the source user has not gone over his/her

        invitation limit or the target user has not been invited already

    """

    num_inv = Invitations.objects.filter(source = source).count()

    if num_inv >= source.max_invitations:

        raise TooManyInvitations("User invitation limit (%d) exhausted" %

                                 source.max_invitations)

    target = SynnefoUser.objects.filter(uniq = email)

    if target.count() is not 0:

        raise AlreadyInvited("User with email %s already invited" % (email))

    users.register_user(name, email)

    target = SynnefoUser.objects.filter(uniq = email)

    r = list(target[:1])

    if not r:

        raise Exception("Invited user cannot be added")

    u = target[0]

    invitee_level = get_invitee_level(source)

    u.max_invitations = settings.INVITATIONS_PER_LEVEL[invitee_level]

    u.save()

    inv = Invitations()

    inv.source = source

    inv.target = u

    inv.level = invitee_level

    inv.save()

    return inv

@transaction.commit_on_success

def invitation_accepted(invitation):

    """

        Mark an invitation as accepted

    """

    invitation.accepted = True

    invitation.save()

class TooManyInvitations(Exception):

    messages = []

    def __init__(self, msg):

        self.messages.append(msg)

class AlreadyInvited(Exception):

    messages = []

    def __init__(self, msg):

        self.messages.append(msg)