# Copyright 2011-2012 GRNET S.A. All rights reserved.
#
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# without modification, are permitted provided that the following
# conditions are met:
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#   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,
# 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
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from django.core.urlresolvers import reverse
from django.utils.translation import ugettext as _
from django.utils.http import urlencode
from django.contrib.auth import authenticate
from django.http import HttpResponse, HttpResponseBadRequest
from django.core.exceptions import ValidationError

from urlparse import urlunsplit, urlsplit, parse_qsl

from astakos.im.settings import COOKIE_NAME, COOKIE_DOMAIN
from astakos.im.util import set_cookie
from astakos.im.functions import login as auth_login, logout

import logging

logger = logging.getLogger(__name__)

def login(request):
    """
    If there is no ``next`` request parameter redirects to astakos index page
    displaying an error message.
    If the request user is authenticated and has signed the approval terms,
    redirects to `next` request parameter. If not, redirects to approval terms
    in order to return back here after agreeing with the terms.
    Otherwise, redirects to login in order to return back here after successful login.
    """
    next = request.GET.get('next')
    if not next:
        return HttpResponseBadRequest(_('No next parameter'))
    force = request.GET.get('force', None)
    response = HttpResponse()
    if force == '':
        logout(request)
        response.delete_cookie(COOKIE_NAME, path='/', domain=COOKIE_DOMAIN)
    if request.user.is_authenticated():
        # if user has not signed the approval terms
        # redirect to approval terms with next the request path
        if not request.user.signed_terms:
            # first build next parameter
            parts = list(urlsplit(request.build_absolute_uri()))
            params = dict(parse_qsl(parts[3], keep_blank_values=True))
            # delete force parameter
            parts[3] = urlencode(params)
            next = urlunsplit(parts)
            
            # build url location
            parts[2] = reverse('latest_terms')
            params = {'next':next}
            parts[3] = urlencode(params)
            url = urlunsplit(parts)
            response['Location'] = url
            response.status_code = 302
            return response
        renew = request.GET.get('renew', None)
        if renew == '':
            request.user.renew_token()
            try:
                request.user.save()
            except ValidationError, e:
                return HttpResponseBadRequest(e)
            # authenticate before login
            user = authenticate(email=request.user.email,
                auth_token=request.user.auth_token
            )
            auth_login(request, user)
            set_cookie(response, user)
            logger.info('Token reset for %s' % request.user.email)
        parts = list(urlsplit(next))
        parts[3] = urlencode({'user': request.user.email,
            'token': request.user.auth_token
            }
        )
        url = urlunsplit(parts)
        response['Location'] = url
        response.status_code = 302
        return response
    else:
        # redirect to login with next the request path
        
        # first build next parameter
        parts = list(urlsplit(request.build_absolute_uri()))
        params = dict(parse_qsl(parts[3], keep_blank_values=True))
        # delete force parameter
        if 'force' in params:
            del params['force']
        parts[3] = urlencode(params)
        next = urlunsplit(parts)
        
        # build url location
        parts[2] = reverse('index')
        params = {'next':next}
        parts[3] = urlencode(params)
        url = urlunsplit(parts)
        response['Location'] = url
        response.status_code = 302
        return response