if qs.count() > 1:

            raise Http404()

        schedule = next(iter(qs), None)

        if schedule is None:

            raise Http404()

    else:

        schedule = get_object_or_404(qs, section__slug=slug)

    return schedule

def schedule_conference(request):

    schedules = Schedule.objects.filter(published=True, hidden=False)

    sections = []

    for schedule in schedules:

        days_qs = Day.objects.filter(schedule=schedule)

        days = [TimeTable(day) for day in days_qs]

        sections.append({

            "schedule": schedule,

            "days": days,

        })

    ctx = {

        "sections": sections,

    }

    return render(request, "symposion/schedule/schedule_conference.html", ctx)

def schedule_detail(request, slug=None):

    schedule = fetch_schedule(slug)

    if not schedule.published and not request.user.is_staff:

        raise Http404()

    days_qs = Day.objects.filter(schedule=schedule)

    days = [TimeTable(day) for day in days_qs]

    ctx = {

        "schedule": schedule,

        "days": days,

    }

    return render(request, "symposion/schedule/schedule_detail.html", ctx)

def schedule_list(request, slug=None):

    schedule = fetch_schedule(slug)

    presentations = Presentation.objects.filter(section=schedule.section)

    presentations = presentations.exclude(cancelled=True)

    ctx = {

        "schedule": schedule,

        "presentations": presentations,

    }

    return render(request, "symposion/schedule/schedule_list.html", ctx)

def schedule_list_csv(request, slug=None):

    schedule = fetch_schedule(slug)

    presentations = Presentation.objects.filter(section=schedule.section)

    presentations = presentations.exclude(cancelled=True).order_by("id")

    response = HttpResponse(content_type="text/csv")

    if slug:

        file_slug = slug

    else:

        file_slug = "presentations"

    response["Content-Disposition"] = 'attachment; filename="%s.csv"' % file_slug

    response.write(loader.get_template("symposion/schedule/schedule_list.csv").render(Context({

        "presentations": presentations,

    })))

    return response

@login_required

def schedule_edit(request, slug=None):

    if not request.user.is_staff:

        raise Http404()

    schedule = fetch_schedule(slug)

    if request.method == "POST":

        form = ScheduleSectionForm(

            request.POST, request.FILES, schedule=schedule

        )

        if form.is_valid():

            if 'submit' in form.data:

                msg = form.build_schedule()

            elif 'delete' in form.data:

                msg = form.delete_schedule()

            messages.add_message(request, msg[0], msg[1])

    else:

        form = ScheduleSectionForm(schedule=schedule)

    days_qs = Day.objects.filter(schedule=schedule)

    days = [TimeTable(day) for day in days_qs]

    ctx = {

        "schedule": schedule,

        "days": days,

        "form": form

    }

    return render(request, "symposion/schedule/schedule_edit.html", ctx)

@login_required

def schedule_slot_edit(request, slug, slot_pk):

    if not request.user.is_staff:

        raise Http404()

    slot = get_object_or_404(Slot, day__schedule__section__slug=slug, pk=slot_pk)

    if request.method == "POST":

        form = SlotEditForm(request.POST, slot=slot)

        if form.is_valid():

            save = False

            if "content_override" in form.cleaned_data:

                slot.content_override = form.cleaned_data["content_override"]

                save = True

            if "presentation" in form.cleaned_data:

                presentation = form.cleaned_data["presentation"]

                if presentation is None:

                    slot.unassign()

                else:

                    slot.assign(presentation)

            if save:

                slot.save()

        return redirect("schedule_edit", slug)

    else:

        form = SlotEditForm(slot=slot)

        ctx = {

            "slug": slug,

            "form": form,

            "slot": slot,

        }

        return render(request, "symposion/schedule/_slot_edit.html", ctx)

def schedule_presentation_detail(request, pk):

    presentation = get_object_or_404(Presentation, pk=pk)

    if presentation.slot:

        schedule = presentation.slot.day.schedule

    else:

        schedule = None

    ctx = {

        "presentation": presentation,

        "schedule": schedule,

    }

    return render(request, "symposion/schedule/presentation_detail.html", ctx)

def schedule_json(request):

    slots = Slot.objects.filter(

        day__schedule__published=True,

        day__schedule__hidden=False

    ).order_by("start")

    protocol = request.META.get('HTTP_X_FORWARDED_PROTO', 'http')

    data = []

    for slot in slots:

        slot_data = {

            "room": ", ".join(room["name"] for room in slot.rooms.values()),

            "rooms": [room["name"] for room in slot.rooms.values()],

            "start": slot.start_datetime.isoformat(),

            "end": slot.end_datetime.isoformat(),

            "duration": slot.length_in_minutes,

            "kind": slot.kind.label,

            "section": slot.day.schedule.section.slug,

            "conf_key": slot.pk,

            # TODO: models should be changed.

            # these are model features from other conferences that have forked symposion

            # these have been used almost everywhere and are good candidates for

            # base proposals

            "license": "CC BY",

            "tags": "",

            "released": True,

            "contact": [],

        }

        if hasattr(slot.content, "proposal"):

            slot_data.update({

                "name": slot.content.title,

                "authors": [s.name for s in slot.content.speakers()],

                "contact": [

                    s.email for s in slot.content.speakers()

                ] if request.user.is_staff else ["redacted"],

                "abstract": slot.content.abstract.raw,

                "description": slot.content.description.raw,