Synnefo

# vim: set fileencoding=utf-8 :

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 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('_')

        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

    )

@transaction.commit_on_success

def add_invitation(source, name, email):

    """

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

        invitation count or the target user has not been invited already

    """

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

    if num_inv >= settings.MAX_INVITATIONS:

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

    inv = Invitations()

    inv.source = source

    inv.target = target[0]

    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)