Fixed #133 -- Transparent quota calculation

src/pretix/base/models/items.py

@@ -488,15 +488,11 @@ class Quota(LoggedModel):
             return Quota.AVAILABILITY_OK, None
 
         # TODO: Test for interference with old versions of Item-Quota-relations, etc.
-        # TODO: Prevent corner-cases like people having ordered an item before it got
+        size_left -= self.count_paid_orders()
-        # its first variationsadde
-        paid, pending = self.count_orders()
-
-        size_left -= paid
         if size_left <= 0:
             return Quota.AVAILABILITY_GONE, 0
 
-        size_left -= pending
+        size_left -= self.count_pending_orders()
         if size_left <= 0:
             return Quota.AVAILABILITY_ORDERED, 0
 
@@ -527,17 +523,20 @@ class Quota(LoggedModel):
             self._position_lookup
         ).distinct().count()
 
-    def count_orders(self) -> dict:
+    def count_pending_orders(self) -> dict:
         from pretix.base.models import Order, OrderPosition
 
-        paid = OrderPosition.objects.filter(
+        return OrderPosition.objects.filter(
-            self._position_lookup, order__status=Order.STATUS_PAID
-        ).distinct().count()
-        pending = OrderPosition.objects.filter(
             self._position_lookup, order__status=Order.STATUS_PENDING,
             order__expires__gte=now()
         ).distinct().count()
-        return paid, pending
+
+    def count_paid_orders(self):
+        from pretix.base.models import Order, OrderPosition
+
+        return OrderPosition.objects.filter(
+            self._position_lookup, order__status=Order.STATUS_PAID
+        ).distinct().count()
 
     @cached_property
     def _position_lookup(self) -> Q:

src/pretix/control/templates/pretixcontrol/items/quota.html

@@ -4,6 +4,8 @@
 {% block title %}{% trans "Quota" %}{% endblock %}
 {% block inside %}
     <h1>{% trans "Quota" %}</h1>
+    <div class="row">
+        <div class="col-xs-12 {% if quota.pk and quota.size != None %}col-lg-9{% else %}col-lg-12{% endif %}">
             <form action="" method="post" class="form-horizontal">
                 {% csrf_token %}
                 {% bootstrap_form_errors form %}
@@ -15,7 +17,8 @@
                     <p>
                         {% blocktrans trimmed %}
                             Please select the products or product variations this quota should be applied to. If you apply two
-                    quotas to the same product, it will only be available if <strong>both</strong> quotas have capacity
+                            quotas to the same product, it will only be available if
+                            <strong>both</strong> quotas have capacity
                             left.
                         {% endblocktrans %}
                     </p>
@@ -41,10 +44,43 @@
                         {% endfor %}
                     </div>
                 </fieldset>
+            </form>
+        </div>
+        {% if quota.pk and quota.size != None %}
+            <div class="col-xs-12 col-lg-3">
+                <fieldset>
+                    <legend>{% trans "Availability calculation" %}</legend>
+                    <div class="row">
+                        <div class="col-xs-9">{% trans "Total quota" %}</div>
+                        <div class="col-xs-3 text-right">{{ quota.size }}</div>
+                    </div>
+                    <div class="row">
+                        <div class="col-xs-9">{% trans "Paid orders" %}</div>
+                        <div class="col-xs-3 text-right"> – {{ quota.count_paid_orders }}</div>
+                    </div>
+                    <div class="row">
+                        <div class="col-xs-9">{% trans "Pending orders" %}</div>
+                        <div class="col-xs-3 text-right"> – {{ quota.count_pending_orders }}</div>
+                    </div>
+                    <div class="row">
+                        <div class="col-xs-9">{% trans "Vouchers" %}</div>
+                        <div class="col-xs-3 text-right"> – {{ quota.count_blocking_vouchers }}</div>
+                    </div>
+                    <div class="row">
+                        <div class="col-xs-9">{% trans "Current user's carts" %}</div>
+                        <div class="col-xs-3 text-right"> – {{ quota.count_in_cart }}</div>
+                    </div>
+                    <div class="row">
+                        <div class="col-xs-9"><strong>{% trans "Current availability" %}</strong></div>
+                        <div class="col-xs-3 text-right"><strong>{{ quota.availability.1 }}</strong></div>
+                    </div>
+                </fieldset>
+            </div>
+        {% endif %}
+    </div>
     <div class="form-group submit-group">
         <button type="submit" class="btn btn-primary btn-save">
             {% trans "Save" %}
         </button>
     </div>
-	</form>
 {% endblock %}