allow for events to be cancelled

ephios/core/forms/events.py

@@ -300,3 +300,26 @@ def clean(self):
         ):
             raise ValidationError(_("You cannot send an empty mail."))
         return super().clean()
+
+
+class EventCancellationForm(forms.Form):
+    explanation = forms.CharField(
+        required=False,
+        widget=forms.Textarea,
+        label=_("Explanation"),
+        help_text=_(
+            "All participants will be notified about the cancellation and this message will be included."
+        ),
+    )
+
+    def __init__(self, *args, **kwargs):
+        self.event = kwargs.pop("event")
+        super().__init__(*args, **kwargs)
+        self.helper = FormHelper(self)
+        self.helper.layout = Layout(
+            Field("explanation"),
+            FormActions(
+                Submit("submit", _("Cancel event"), css_class="float-end"),
+                AbortLink(href=self.event.get_absolute_url()),
+            ),
+        )

ephios/core/services/notifications/types.py

@@ -1,4 +1,4 @@
-from typing import List
+from typing import List, Optional
 from urllib.parse import urljoin
 
 from django.conf import settings
@@ -497,6 +497,48 @@ def as_plaintext(cls, notification):
         return notification.data.get("content")
 
 
+class EventCancellationNotification(AbstractNotificationHandler):
+    slug = "ephios_event_cancellation"
+    title = _("An event has been cancelled")
+    unsubscribe_allowed = False
+
+    @classmethod
+    def send(cls, event: Event, explanation: Optional[str]):
+        participants = set()
+        for shift in event.shifts.all():
+            participants.update(shift.get_participants())
+        notifications = []
+        for participant in participants:
+            notifications.append(
+                Notification(
+                    slug=cls.slug,
+                    data={
+                        "email": participant.email,
+                        "event_title": event.title,
+                        "start_time": date_format(event.get_start_time(), "SHORT_DATETIME_FORMAT"),
+                        "end_time": date_format(event.get_start_time(), "SHORT_DATETIME_FORMAT"),
+                        "explanation": explanation,
+                    },
+                )
+            )
+        Notification.objects.bulk_create(notifications)
+
+    @classmethod
+    def get_subject(cls, notification):
+        return _("{title} has been cancelled").format(title=notification.data.get("event_title"))
+
+    @classmethod
+    def as_plaintext(cls, notification):
+        result = _("{title} ({start_time} - {end_time}) has been cancelled.").format(
+            title=notification.data.get("event_title"),
+            start_time=notification.data.get("start_time"),
+            end_time=notification.data.get("end_time"),
+        )
+        if explanation := notification.data.get("explanation"):
+            result += _(" Further information:\n{explanation}").format(explanation=explanation)
+        return result
+
+
 class ConsequenceApprovedNotification(AbstractNotificationHandler):
     slug = "ephios_consequence_approved"
     title = _("Your request has been approved")
@@ -549,6 +591,7 @@ def as_plaintext(cls, notification):
     NewEventNotification,
     EventReminderNotification,
     CustomEventParticipantNotification,
+    EventCancellationNotification,
     ConsequenceApprovedNotification,
     ConsequenceDeniedNotification,
 ]

ephios/core/templates/core/event_cancellation.html

@@ -0,0 +1,12 @@
+{% extends "base.html" %}
+{% load crispy_forms_tags %}
+{% load i18n %}
+
+{% block title %}
+    {% translate "Cancel event" %}
+{% endblock %}
+
+{% block content %}
+    <h1 class="page-header">{% blocktranslate %}Cancel event "{{ event }}"{% endblocktranslate %}</h1>
+    {% crispy form %}
+{% endblock %}

ephios/core/templates/core/event_detail.html

@@ -56,6 +56,12 @@ <h1 class="card-title fw-bold fs-1">
                                 <span class="fas fa-plus"></span>
                                 {% trans "Add another shift" %}
                             </a></li>
+                            <li><a class="dropdown-item"
+                                       href="{% url "core:event_cancel" event.pk %}">
+                                    <span class="fas fa-ban"></span>
+                                    {% translate "Cancel event" %}
+                                </a>
+                                </li>
                             <li><a class="dropdown-item"
                                    href="{% url "core:event_delete" event.pk %}">
                                 <span class="fas fa-trash-alt"></span>

ephios/core/urls.py

@@ -22,6 +22,7 @@
 from ephios.core.views.consequences import ConsequenceUpdateView
 from ephios.core.views.event import (
     EventActivateView,
+    EventCancellationView,
     EventCopyView,
     EventCreateView,
     EventDeleteView,
@@ -99,6 +100,7 @@
         name="event_notifications",
     ),
     path("events/<int:pk>/pdf/", pdf.EventDetailPDFView.as_view(), name="event_detail_pdf"),
+    path("events/<int:pk>/cancel/", EventCancellationView.as_view(), name="event_cancel"),
     path(
         "events/<int:pk>/copy/",
         EventCopyView.as_view(),

ephios/core/views/event.py

@@ -33,10 +33,16 @@
 from recurrence.forms import RecurrenceField
 
 from ephios.core.calendar import ShiftCalendar
-from ephios.core.forms.events import EventDuplicationForm, EventForm, EventNotificationForm
+from ephios.core.forms.events import (
+    EventCancellationForm,
+    EventDuplicationForm,
+    EventForm,
+    EventNotificationForm,
+)
 from ephios.core.models import AbstractParticipation, Event, EventType, Shift
 from ephios.core.services.notifications.types import (
     CustomEventParticipantNotification,
+    EventCancellationNotification,
     EventReminderNotification,
     NewEventNotification,
 )
@@ -509,3 +515,26 @@ def form_valid(self, form):
             CustomEventParticipantNotification.send(self.object, form.cleaned_data["mail_content"])
         messages.success(self.request, _("Notifications sent succesfully."))
         return redirect(self.object.get_absolute_url())
+
+
+class EventCancellationView(CustomPermissionRequiredMixin, SingleObjectMixin, FormView):
+    model = Event
+    permission_required = "core.change_event"
+    template_name = "core/event_cancellation.html"
+    form_class = EventCancellationForm
+
+    def get_form_kwargs(self):
+        return {**super().get_form_kwargs(), "event": self.object}
+
+    def setup(self, request, *args, **kwargs):
+        super().setup(request, *args, **kwargs)
+        self.object = self.get_object()
+
+    def form_valid(self, form):
+        EventCancellationNotification.send(self.object, form.cleaned_data["explanation"])
+        event_title = self.object.title
+        self.object.delete()
+        messages.info(
+            self.request, _("Event {title} has been cancelled.").format(title=event_title)
+        )
+        return redirect(reverse("core:event_list"))