backoffice: add average price across all tickets of the given type to the tickettype stats detail view

src/backoffice/templates/ticket_stats_detail.html

@@ -51,6 +51,7 @@
     </tfoot>
   </table>
   <br>
+  <p class="lead">The average price of the <b>{{ total_units }}</b> tickets with the ticket type <b>{{ product_list.0.ticket_type.name }}</b> is <b>{{ average_price|floatformat:"2" }}</b>&nbsp;DKK.</p>
   <p class="lead">Note: This view only shows tickets, which are generated based on paid orders. Unpaid orders are not included here.</p>
   <a class="btn btn-default" href="{% url 'backoffice:shop_ticket_stats' camp_slug=camp.slug %}"><i class="fas fa-undo"></i> Back to Ticket Types</a>
   </p>

src/backoffice/views/orga.py

@@ -228,4 +228,7 @@ class ShopTicketStatsDetailView(CampViewMixin, OrgaTeamPermissionMixin, ListView
             context["total_income"] += product.total_income
             context["total_cost"] += product.total_cost
             context["total_profit"] += product.total_profit
+        context["average_price"] = round(
+            context["total_income"] / context["total_units"], 2
+        )
         return context

src/tickets/models.py

@@ -138,6 +138,8 @@ class DiscountTicket(BaseTicket):
 
 
 class ShopTicket(BaseTicket):
+    """Why doesn't this have an FK to OrderProductRelation instead of the fk to Order?"""
+
     order = models.ForeignKey(
         "shop.Order", related_name="shoptickets", on_delete=models.PROTECT
     )