import re from django conf import settings from django http import Htt

import re
from django.conf import settings
from django.http import Http404, HttpResponsePermanentRedirect
from django.utils import translation
from django.utils.cache import patch_vary_headers
       
class RedirectLanguage(Exception):
    pass

class LocaleURLMiddleware:
    def get_language_from_request(self, request):
        supported = dict(settings.LANGUAGES)
        lang = settings.LANGUAGE_CODE[:2]
        check = re.match(r"^/(\w\w)/.*", request.path)
        changed = False
        if check is not None:
            print 'Found lang'
            url_list = request.path.split('/')
            t = check.group(1)
            if t in url_list and url_list.index(t) == 1:
                del url_list[1]
                request.path = u'/'.join(url_list)
                print request.path
            if t in supported:
                lang = t
                if hasattr(request, 'session'):
                    request.session['django_language'] = lang
                else:
                    response.set_cookie('django_language', lang)
                changed = True
        else:
            raise RedirectLanguage
        if not changed:
            if hasattr(request, 'session'):
                lang = request.session.get('django_language', None)
                if lang in supported and lang is not None:
                    return lang
            else:
                lang = request.COOKIES.get('django_language', None)
                if lang in supported and lang is not None:
                    return lang
        return lang

    def process_request(self, request):
        language = self.get_language_from_request(request)
        if language is None:
            language = settings.LANGUAGE_CODE[:2]
        translation.activate(language)
        request.LANGUAGE_CODE = translation.get_language()

    def process_response(self, request, response):
        patch_vary_headers(response, ('Accept-Language',))
        translation.deactivate()
        return response

    def process_exception(self, request, exception):
        if isinstance(exception,RedirectLanguage):
            redir_url = '/%s%s' % (request.LANGUAGE_CODE, request.path)
            print 'lang not found in url, redirecting to %s' % redir_url
            return HttpResponsePermanentRedirect(redir_url)