# -*- coding: utf-8 -*-
from __future__ import with_statement
from django.contrib.auth.views import redirect_to_login
from django.template.response import TemplateResponse
from cms.apphook_pool import apphook_pool
from cms.appresolver import get_app_urls
from cms.models import Title
from cms.utils import get_template_from_request, get_language_from_request
from cms.utils.i18n import get_fallback_languages, force_language, get_public_languages, get_redirect_on_fallback, \
    get_language_list, is_language_prefix_patterns_used
from cms.utils.page_resolver import get_page_from_request
from cms.test_utils.util.context_managers import SettingsOverride
from django.conf import settings
from django.conf.urls import patterns
from django.core.urlresolvers import resolve, Resolver404, reverse
from django.http import Http404, HttpResponseRedirect
from django.template.context import RequestContext
from django.utils.http import urlquote


def _handle_no_page(request, slug):
    if not slug and settings.DEBUG:
        return TemplateResponse(request, "cms/welcome.html", RequestContext(request))
    raise Http404('CMS: Page not found for "%s"' % slug)


def details(request, slug):
    """
    The main view of the Django-CMS! Takes a request and a slug, renders the
    page.
    """
    # get the right model
    context = RequestContext(request)
    # Get a Page model object from the request
    page = get_page_from_request(request, use_path=slug)
    if not page:
        return _handle_no_page(request, slug)

    current_language = get_language_from_request(request)
    # Check that the current page is available in the desired (current) language
    available_languages = []
    page_languages = list(page.get_languages())
    if hasattr(request, 'user') and request.user.is_staff:
        user_languages = get_language_list()
    else:
        user_languages = get_public_languages()
    for frontend_lang in user_languages:
        if frontend_lang in page_languages:
            available_languages.append(frontend_lang)
    attrs = ''
    if 'edit' in request.GET:
        attrs = '?edit=1'
    elif 'preview' in request.GET:
        attrs = '?preview=1'
        if 'draft' in request.GET:
            attrs += '&draft=1'
        # Check that the language is in FRONTEND_LANGUAGES:
    if not current_language in user_languages:
        #are we on root?
        if not slug:
            #redirect to supported language
            languages = []
            for language in available_languages:
                languages.append((language, language))
            if languages:
                with SettingsOverride(LANGUAGES=languages, LANGUAGE_CODE=languages[0][0]):
                    #get supported language
                    new_language = get_language_from_request(request)
                    if new_language in get_public_languages():
                        with force_language(new_language):
                            pages_root = reverse('pages-root')
                            return HttpResponseRedirect(pages_root + attrs)
            else:
                _handle_no_page(request, slug)
        else:
            return _handle_no_page(request, slug)
    if current_language not in available_languages:
        # If we didn't find the required page in the requested (current)
        # language, let's try to find a fallback
        found = False
        for alt_lang in get_fallback_languages(current_language):
            if alt_lang in available_languages:
                if get_redirect_on_fallback(current_language):
                    with force_language(alt_lang):
                        path = page.get_absolute_url(language=alt_lang, fallback=True)
                        # In the case where the page is not available in the
                    # preferred language, *redirect* to the fallback page. This
                    # is a design decision (instead of rendering in place)).
                    return HttpResponseRedirect(path + attrs)
                else:
                    found = True
        if not found:
            # There is a page object we can't find a proper language to render it
            _handle_no_page(request, slug)

    if apphook_pool.get_apphooks():
        # There are apphooks in the pool. Let's see if there is one for the
        # current page
        # since we always have a page at this point, applications_page_check is
        # pointless
        # page = applications_page_check(request, page, slug)
        # Check for apphooks! This time for real!
        try:
            app_urls = page.get_application_urls(current_language, False)
        except Title.DoesNotExist:
            app_urls = []
        if app_urls:
            app = apphook_pool.get_apphook(app_urls)
            pattern_list = []
            for urlpatterns in get_app_urls(app.urls):
                pattern_list += urlpatterns
            urlpatterns = patterns('', *pattern_list)
            try:
                view, args, kwargs = resolve('/', tuple(urlpatterns))
                return view(request, *args, **kwargs)
            except Resolver404:
                pass
                # Check if the page has a redirect url defined for this language.
    redirect_url = page.get_redirect(language=current_language)
    if redirect_url:
        if (is_language_prefix_patterns_used() and redirect_url[0] == "/"
        and not redirect_url.startswith('/%s/' % current_language)):
            # add language prefix to url
            redirect_url = "/%s/%s" % (current_language, redirect_url.lstrip("/"))
            # prevent redirect to self
        own_urls = [
            'http%s://%s%s' % ('s' if request.is_secure() else '', request.get_host(), request.path),
            '/%s' % request.path,
            request.path,
        ]
        if redirect_url not in own_urls:
            return HttpResponseRedirect(redirect_url + attrs)

    # permission checks
    if page.login_required and not request.user.is_authenticated():
        return redirect_to_login(urlquote(request.get_full_path()), settings.LOGIN_URL)

    template_name = get_template_from_request(request, page, no_current_page=True)
    # fill the context 
    context['lang'] = current_language
    context['current_page'] = page
    context['has_change_permissions'] = page.has_change_permission(request)
    context['has_view_permissions'] = page.has_view_permission(request)

    if not context['has_view_permissions']:
        return _handle_no_page(request, slug)

    return TemplateResponse(request, template_name, context)
