# -*- coding: utf-8 -*-
# Copyright (c) 2013, First Party Software
# All rights reserved.

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# 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.

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# this list of conditions and the following disclaimer in the documentation 
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import pytz
from re import compile
from django.conf import settings
from django.utils import timezone
from django.http import HttpResponseRedirect


if hasattr(settings, 'LOGIN_EXEMPT_URLS'):
    EXEMPT_URLS = [compile(expr) for expr in settings.LOGIN_EXEMPT_URLS]


class LoginRequiredMiddleware(object):
    """
    Middleware that requires a user to be authenticated to view any page other
    than LOGIN_URL. Exemptions to this requirement can optionally be specified
    in settings via a list of regular expressions in LOGIN_EXEMPT_URLS (which
    you can copy from your urls.py).

    Requires authentication middleware and template context processors to be
    loaded. You'll get an error if they aren't.
    """
    def process_request(self, request):
        assert hasattr(request, 'user'), "The Login Required middleware\
 requires authentication middleware to be installed. Edit your\
 MIDDLEWARE_CLASSES setting to insert\
 'django.contrib.auth.middlware.AuthenticationMiddleware'. If that doesn't\
 work, ensure your TEMPLATE_CONTEXT_PROCESSORS setting includes\
 'django.core.context_processors.auth'."
        if not request.user.is_authenticated():
            path = request.path_info.lstrip('/')
            if not any(m.match(path) for m in EXEMPT_URLS):
                return HttpResponseRedirect(settings.LOGIN_URL)


class TimezoneMiddleware(object):
    def process_request(self, request):
        tzname = request.session.get('django_timezone')
        if tzname:
            timezone.activate(pytz.timezone(tzname))
        else:
            timezone.deactivate()