add cancel functionality to shift reservations

shiftregister/app/models.py

@@ -1,6 +1,8 @@
 from django.db import models
 import secrets
 from django.shortcuts import reverse
+from datetime import timedelta
+from django.utils import timezone
 
 class Room(models.Model):
     name = models.CharField(max_length=200, primary_key=True)
@@ -37,6 +39,8 @@ class ShiftRegistration(models.Model):
     # use restrict for now as Model.delete is not called
     shift = models.ForeignKey(Shift, on_delete=models.RESTRICT)
     helper = models.ForeignKey(Helper, on_delete=models.CASCADE)
+    def can_cancel(self):
+        return self.shift.start_at>(timezone.now()+timedelta(hours=4))
 
 class Message(models.Model):
     # remove limit and send long messages in multiple messages?

shiftregister/app/templates/shift.html

@@ -15,4 +15,15 @@ Dauer: {{shift.duration}}<br>
 <input type="submit" value="Anmelden">
 </form>
 {%endif%}
+{% if is_registered%}
+{% if can_cancel %}
+<form action="{%url 'cancel' shift.pk%}" method="post">
+    {% csrf_token %}
+{{shift_form.as_p}}
+<input type="submit" value="Abmelden">
+</form>
+{%else%}
+Bitte wende dich an den Infopoint falls du es nicht zu deiner Schicht schaffst.
+{%endif%}
+{% endif %}
 {% endblock %}

shiftregister/app/urls.py

@@ -8,4 +8,5 @@ urlpatterns = [
     path('logout', views.logout, name='token_logout'),
     path('register', views.register, name='register'),
     path('shift/<int:shiftid>', views.shift, name='shift'),
+    path('shift/<int:shiftid>/cancel', views.cancel, name='cancel'),
 ]

shiftregister/app/views.py

@@ -61,6 +61,7 @@ def shift(request, shiftid):
     helper = None
     context = {  'can_register':False,
                         'is_registered':False,
+                        'can_cancel': False,
                         'shift':shift,
                         'shift_form': EmptyForm,
                     }
@@ -71,9 +72,12 @@ def shift(request, shiftid):
     if request.session.get('token'):
         helper = LoginToken.objects.get(pk=request.session['token']).helper
         context['helper'] =helper
-        if ShiftRegistration.objects.filter(shift=shift, helper=helper).count()!=0:
+        reg =  ShiftRegistration.objects.filter(shift=shift, helper=helper)
+        if reg:
             context['is_registered']=True
             context['can_register']=False
+            if reg[0].can_cancel():
+                context['can_cancel'] = True
     if request.method=='POST':
         if EmptyForm(request.POST).is_valid():
             if not helper:
@@ -84,4 +88,18 @@ def shift(request, shiftid):
                 s.save()
                 # redirect so page can be reloaded without resending post data
                 return redirect('shift', shiftid=shift.pk)
-    return render(request, 'shift.html', context)
+    return render(request, 'shift.html', context)
+
+def cancel(request, shiftid):
+    if request.method!='POST':
+         return redirect('shift', shiftid=shiftid)
+    if not EmptyForm(request.POST).is_valid():
+        return redirect('shift', shiftid=shiftid)
+    if not request.session.get('token'):
+        return redirect('shift', shiftid=shiftid)
+    helper = LoginToken.objects.get(pk=request.session['token']).helper
+    shift = get_object_or_404(Shift, pk=shiftid)
+    reg = get_object_or_404(ShiftRegistration, helper=helper, shift=shift)
+    if reg.can_cancel():
+        reg.delete()
+    return redirect('shift', shiftid=shiftid)

shiftregister/settings.py

@@ -106,7 +106,7 @@ AUTH_PASSWORD_VALIDATORS = [
 
 LANGUAGE_CODE = 'en-us'
 
-TIME_ZONE = 'UTC'
+TIME_ZONE = 'Europe/Berlin'
 
 USE_I18N = True