from django.conf import settings
from django.contrib.auth.decorators import login_required
from django.core.exceptions import PermissionDenied
from django.shortcuts import get_object_or_404, redirect
from django.urls import reverse
from django.utils import timezone
from django.views.decorators.cache import never_cache
from django.views.decorators.http import require_GET

from apps.accounts.models import User
from .models import StaffTicketShortLink
from .policies import TicketPolicy


def append_supervisor_ticket_link(ticket, message):
    unit = ticket.owning_unit
    if not unit or not unit.supervisor_sms_ticket_link_enabled:
        return message
    link, _ = StaffTicketShortLink.objects.get_or_create(ticket=ticket)
    if link.expires_at <= timezone.now():
        return message
    url = settings.PUBLIC_BASE_URL.rstrip("/") + reverse("staff_ticket_short_link", args=[link.token])
    return f"{message}\nمشاهده و پاسخ: {url}"


@never_cache
@require_GET
@login_required(login_url="/staff/login/")
def open_staff_ticket_link(request, token):
    if not request.user.is_active or request.user.account_type != User.AccountType.STAFF:
        raise PermissionDenied
    link = get_object_or_404(
        StaffTicketShortLink.objects.select_related("ticket"),
        token=token, expires_at__gt=timezone.now(),
    )
    if not TicketPolicy.can_view(request.user, link.ticket):
        raise PermissionDenied
    return redirect("staff_tickets:detail", public_id=link.ticket.public_id)