views.py

__copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
__license__ = "AGPL v3"


from django.contrib import messages
from django.contrib.auth.mixins import LoginRequiredMixin, UserPassesTestMixin
from django.contrib.contenttypes.models import ContentType
from django.shortcuts import get_object_or_404, redirect
from django.urls import reverse_lazy
from django.utils import timezone
from django.views.generic.detail import DetailView
from django.views.generic.edit import CreateView, UpdateView, DeleteView
from django.views.generic.list import ListView

from guardian.mixins import PermissionRequiredMixin
from guardian.shortcuts import get_groups_with_perms, get_objects_for_user, remove_perm
from scipost.mixins import PermissionsMixin

from .constants import (
    TICKET_STATUS_UNASSIGNED, TICKET_STATUS_ASSIGNED,
    TICKET_STATUS_PICKEDUP, TICKET_STATUS_PASSED_ON,
    TICKET_STATUS_AWAITING_RESPONSE_ASSIGNEE, TICKET_STATUS_AWAITING_RESPONSE_USER,
    TICKET_STATUS_RESOLVED, TICKET_STATUS_CLOSED,
    TICKET_FOLLOWUP_ACTION_UPDATE, TICKET_FOLLOWUP_ACTION_RESPONDED_TO_USER,
    TICKET_FOLLOWUP_ACTION_USER_RESPONDED,
    TICKET_FOLLOWUP_ACTION_MARK_RESOLVED, TICKET_FOLLOWUP_ACTION_MARK_CLOSED)
from .models import Queue, Ticket, Followup
from .forms import QueueForm, TicketForm, TicketAssignForm, FollowupForm


class HelpdeskView(ListView):
    model = Queue
    template_name = 'helpdesk/helpdesk.html'

    def get_queryset(self):
        return get_objects_for_user(self.request.user, 'helpdesk.can_view_queue').anchors()


class QueueCreateView(PermissionsMixin, CreateView):
    """
    Add a new Queue. Accessible to users with permission: can_add_queue.
    """
    permission_required = 'helpdesk.add_queue'
    model = Queue
    form_class= QueueForm
    template_name = 'helpdesk/queue_form.html'

    def get_initial(self, *args, **kwargs):
        initial = super().get_initial(*args, **kwargs)
        try:
            parent_slug = self.kwargs.get('parent_slug')
            parent_queue = get_object_or_404(Queue, slug=parent_slug)
            initial.update({
                'managing_group': parent_queue.managing_group,
                'response_groups': parent_queue.response_groups.all(),
                'parent_queue': parent_queue,
            })
        except KeyError:
            pass
        return initial


class QueueUpdateView(PermissionRequiredMixin, UpdateView):
    permission_required = 'helpdesk.update_queue'
    model = Queue
    form_class= QueueForm
    template_name = 'helpdesk/queue_form.html'


class QueueDeleteView(PermissionRequiredMixin, DeleteView):
    permission_required = 'helpdesk.delete_queue'
    model = Queue
    success_url = reverse_lazy('helpdesk:helpdesk')

    def delete(self, request, *args, **kwargs):
        """
        A Queue can only be deleted if it has no descendant Queues.
        Upon deletion, all object-level permissions associated to the
        Queue are explicitly removed, to avoid orphaned permissions.
        """
        queue = get_object_or_404(Queue, slug=self.kwargs.get('slug'))
        groups_perms_dict = get_groups_with_perms(queue, attach_perms=True)
        if queue.sub_queues.all().count() > 0:
            messages.warning(request, 'A Queue with sub-queues cannot be deleted.')
            return redirect(queue.get_absolute_url())
        for group, perms_list in groups_perms_dict.items():
            for perm in perms_list:
                remove_perm(perm, group, queue)
        return super().delete(request, *args, **kwargs)


class QueueDetailView(PermissionRequiredMixin, DetailView):
    permission_required = 'helpdesk.can_view_queue'
    model = Queue
    template_name = 'helpdesk/queue_detail.html'


class TicketCreateView(LoginRequiredMixin, CreateView):
    model = Ticket
    form_class = TicketForm
    template_name = 'helpdesk/ticket_form.html'

    def get_context_data(self, *args, **kwargs):
        context = super().get_context_data(*args, **kwargs)
        concerning_type_id = self.kwargs.get('concerning_type_id')
        concerning_object_id = self.kwargs.get('concerning_object_id')
        if concerning_type_id and concerning_object_id:
            concerning_object_type = ContentType.objects.get_for_id(concerning_type_id)
            concerning_object = concerning_object_type.get_object_for_this_type(pk=concerning_object_id)
            context['concerning_object'] = concerning_object
        return context

    def get_initial(self, *args, **kwargs):
        initial = super().get_initial(*args, **kwargs)
        initial.update({
            'defined_on': timezone.now(),
            'defined_by': self.request.user,
            'status': TICKET_STATUS_UNASSIGNED,
        })
        try:
            concerning_type_id = self.kwargs.get('concerning_type_id')
            concerning_object_id = self.kwargs.get('concerning_object_id')
            if concerning_type_id and concerning_object_id:
                concerning_object_type = ContentType.objects.get_for_id(concerning_type_id)
                initial.update({
                    'concerning_object_type': concerning_object_type,
                    'concerning_object_id': concerning_object_id,
                })
        except KeyError:
            pass

        return initial


class TicketUpdateView(UserPassesTestMixin, UpdateView):
    model = Ticket
    form_class = TicketForm
    template_name = 'helpdesk/ticket_form.html'

    def test_func(self):
        ticket = get_object_or_404(Ticket, pk=self.kwargs.get('pk'))
        return self.request.user.groups.filter(name=ticket.queue.managing_group.name).exists()

    def form_valid(self, form):
        ticket = get_object_or_404(Ticket, pk=self.kwargs.get('pk'))
        text = 'Ticket updated by %s' % (self.request.user.get_full_name())
        followup = Followup(ticket=ticket, text=text, by=self.request.user,
                            timestamp=timezone.now(), action=TICKET_FOLLOWUP_ACTION_UPDATE)
        followup.save()
        return super().form_valid(form)


class TicketDeleteView(UserPassesTestMixin, DeleteView):
    model = Ticket
    success_url = reverse_lazy('helpdesk:helpdesk')

    def test_func(self):
        ticket = get_object_or_404(Ticket, pk=self.kwargs.get('pk'))
        return self.request.user.groups.filter(name=ticket.queue.managing_group.name).exists()


class TicketAssignView(UserPassesTestMixin, UpdateView):
    model = Ticket
    form_class = TicketAssignForm
    template_name = 'helpdesk/ticket_assign.html'

    def test_func(self):
        ticket = get_object_or_404(Ticket, pk=self.kwargs.get('pk'))
        return self.request.user.groups.filter(name=ticket.queue.managing_group.name).exists()

    def form_valid(self, form):
        self.object.status = TICKET_STATUS_ASSIGNED
        return super().form_valid(form)


def is_ticket_creator_or_handler(request, pk):
    """Details of a ticket can only be viewed by ticket creator, or handlers."""
    ticket = get_object_or_404(Ticket, pk=pk)
    if request.user == ticket.defined_by:
        return True
    elif request.user.has_perm('can_view_queue', ticket.queue):
        return True
    elif request.user.has_perm('can_view_ticket', ticket):
        return True
    return False


class TicketDetailView(UserPassesTestMixin, DetailView):
    model = Ticket
    template_name = 'helpdesk/ticket_detail.html'

    def test_func(self):
        return is_ticket_creator_or_handler(self.request, self.kwargs.get('pk'))


class TicketFollowupView(UserPassesTestMixin, CreateView):
    model = Followup
    form_class = FollowupForm
    template_name = 'helpdesk/followup_form.html'

    def test_func(self):
        return is_ticket_creator_or_handler(self.request, self.kwargs.get('pk'))

    def get_initial(self):
        initial = super().get_initial()
        ticket = get_object_or_404(Ticket, pk=self.kwargs.get('pk'))
        if self.request.user == ticket.defined_by:
            action = TICKET_FOLLOWUP_ACTION_USER_RESPONDED
        else:
            action = TICKET_FOLLOWUP_ACTION_RESPONDED_TO_USER
        initial.update({
            'ticket': ticket,
            'by': self.request.user,
            'timestamp': timezone.now(),
            'action': action
        })
        return initial

    def form_valid(self, form):
        ticket = form.cleaned_data['ticket']
        if self.request.user == ticket.defined_by:
            ticket.status = TICKET_STATUS_AWAITING_RESPONSE_ASSIGNEE
        else:
            ticket.status = TICKET_STATUS_AWAITING_RESPONSE_USER
        ticket.save()
        return super().form_valid(form)


class TicketMarkResolved(TicketFollowupView):

    def get_initial(self):
        initial = super().get_initial()
        text = '%s %s marked this ticket as Resolved.' % (self.request.user.first_name,
                                                         self.request.user.last_name)
        initial.update({
            'text': text,
            'action': TICKET_FOLLOWUP_ACTION_MARK_RESOLVED})
        return initial

    def form_valid(self, form):
        ticket = form.cleaned_data['ticket']
        ticket.status = TICKET_STATUS_RESOLVED
        ticket.save()
        self.object = form.save()
        return redirect(self.get_success_url())


class TicketMarkClosed(TicketFollowupView):

    def get_initial(self):
        initial = super().get_initial()
        text = '%s %s marked this ticket as Closed.' % (self.request.user.first_name,
                                                       self.request.user.last_name)
        initial.update({
            'text': text,
            'action': TICKET_FOLLOWUP_ACTION_MARK_CLOSED})
        return initial

    def form_valid(self, form):
        ticket = form.cleaned_data['ticket']
        ticket.status = TICKET_STATUS_CLOSED
        ticket.save()
        self.object = form.save()
        return redirect(self.get_success_url())