from urllib.parse import urljoin

from django.core.exceptions import PermissionDenied
from django.core.urlresolvers import resolve
from django.http import Http404
from django.shortcuts import redirect
from django.utils.translation import ugettext_lazy as _

from pretix.base.middleware import LocaleMiddleware
from pretix.base.models import Event, EventPermission, Organizer
from pretix.multidomain.urlreverse import get_domain
from pretix.presale.signals import process_request


def _detect_event(request):
    url = resolve(request.path_info)
    try:
        if hasattr(request, 'organizer'):
            # We are on an organizer's custom domain
            if 'organizer' in url.kwargs and url.kwargs['organizer']:
                if url.kwargs['organizer'] != request.organizer.slug:
                    raise Http404(_('The selected event was not found.'))
                path = "/" + request.get_full_path().split("/", 2)[-1]
                return redirect(path)

            request.event = Event.objects\
                .select_related('organizer')\
                .get(
                    slug=url.kwargs['event'],
                    organizer=request.organizer,
                )
            request.organizer = request.event.organizer
        else:
            # We are on our main domain
            if 'event' in url.kwargs and 'organizer' in url.kwargs:
                request.event = Event.objects\
                    .select_related('organizer')\
                    .get(
                        slug=url.kwargs['event'],
                        organizer__slug=url.kwargs['organizer']
                    )
                request.organizer = request.event.organizer
            elif 'organizer' in url.kwargs:
                request.organizer = Organizer.objects.get(
                    slug=url.kwargs['organizer']
                )
            else:
                raise Http404()

            # If this organizer has a custom domain, send the user there
            domain = get_domain(request.organizer)
            if domain:
                if request.port and request.port not in (80, 443):
                    domain = '%s:%d' % (domain, request.port)
                path = request.get_full_path().split("/", 2)[-1]
                return redirect(urljoin('%s://%s' % (request.scheme, domain), path))

        if hasattr(request, 'event'):
            # Restrict locales to the ones available for this event
            LocaleMiddleware().process_request(request)

            if not request.event.live:
                if not request.user.is_authenticated() or not EventPermission.objects.filter(
                        event=request.event, user=request.user).exists():
                    raise PermissionDenied(_('The selected ticket shop is currently not available.'))

            for receiver, response in process_request.send(request.event, request=request):
                if response:
                    return response

    except Event.DoesNotExist:
        raise Http404(_('The selected event was not found.'))
    except Organizer.DoesNotExist:
        raise Http404(_('The selected organizer was not found.'))


def event_view(func):
    def wrap(request, *args, **kwargs):
        ret = _detect_event(request)
        if ret:
            return ret
        else:
            return func(request=request, *args, **kwargs)
    return wrap