Update admin. Fix some more tests. Add stock info to template.

src/shop/admin.py

@@ -90,6 +90,15 @@ def available_to(product):
 available_to.short_description = 'Available to'
 
 
+def stock_info(product):
+    if product.stock_amount:
+        return "{} / {}".format(
+            product.left_in_stock,
+            product.stock_amount
+        )
+    return "N/A"
+
+
 @admin.register(Product)
 class ProductAdmin(admin.ModelAdmin):
     list_display = [
@@ -98,6 +107,7 @@ class ProductAdmin(admin.ModelAdmin):
         'ticket_type',
         'price',
         'description',
+        stock_info,
         available_from,
         available_to
     ]

src/shop/models.py

@@ -349,10 +349,16 @@ class Product(CreatedUpdatedModel, UUIDModel):
         - Whether now is in the self.available_in
         - If a stock is defined, that there are items left
         """
+        predicates = [self.is_time_available]
+        if self.stock_amount:
+            predicates.append(self.is_stock_available)
+        return all(predicates)
+
+    @property
+    def is_time_available(self):
         now = timezone.now()
         time_available = now in self.available_in
-        stock_available = self.left_in_stock() > 0
-        return time_available and stock_available
+        return time_available
 
     def is_old(self):
         now = timezone.now()
@@ -364,16 +370,26 @@ class Product(CreatedUpdatedModel, UUIDModel):
         now = timezone.now()
         return self.available_in.lower > now
 
+    @property
     def left_in_stock(self):
-        sold = OrderProductRelation.objects.filter(
-            product=self,
-            order__paid=True,
-        ).aggregate(Sum('quantity'))['quantity__sum']
+        if self.stock_amount:
+            sold = OrderProductRelation.objects.filter(
+                product=self,
+                order__paid=True,
+            ).aggregate(Sum('quantity'))['quantity__sum']
 
-        total_left = self.stock_amount - (sold or 0)
+            total_left = self.stock_amount - (sold or 0)
 
-        return total_left
+            return total_left
+        return None
 
+    @property
+    def is_stock_available(self):
+        if self.stock_amount:
+            stock_available = self.left_in_stock > 0
+            return stock_available
+        # If there is no stock defined the product is generally available.
+        return True
 
 class OrderProductRelation(CreatedUpdatedModel):
     order = models.ForeignKey('shop.Order', on_delete=models.PROTECT)

src/shop/templates/product_detail.html

@@ -25,15 +25,21 @@
 
     <hr />
 
-    {% if product.stock_amount %}
+    {% if product.stock_amount and product.is_time_available %}
     <h3>
       <small>Availability</small><br />
+      {% if product.left_in_stock > 0 %}
       <bold>{{ product.left_in_stock }}</bold> available<br />
+      {% else %}
+      <bold>Sold out.</bold>
+      {% endif %}
     </h3>
 
     <hr />
     {% endif %}
 
+    {% if product.is_stock_available %}
+
     <h3>Add to order</h3>
 
     {% if user.is_authenticated %}
@@ -67,6 +73,8 @@
     to order this product
     {% endif %}
 
+    {% endif %}
+
   </div>
 
 </div>

src/shop/templates/shop_index.html

@@ -47,7 +47,6 @@ Shop | {{ block.super }}
               </a>
             </strong>
           </td>
-          </td>
         </tr>
         {% endifchanged %}
 
@@ -56,6 +55,11 @@ Shop | {{ block.super }}
             <a href="{% url 'shop:product_detail' slug=product.slug %}">
             {{ product.name }}
             </a>
+            {% if product.stock_amount and product.left_in_stock <= 10 %}
+            <div class="label label-danger">
+            Only {{ product.left_in_stock }} left!
+            </div>
+            {% endif %}
           </td>
           <td>
             <div class="pull-right">

src/shop/tests.py

@@ -1,4 +1,7 @@
 from django.test import TestCase
+from django.utils import timezone
+
+from psycopg2.extras import DateTimeTZRange
 
 from .factories import (
     ProductFactory,
@@ -13,8 +16,8 @@ class ProductAvailabilityTest(TestCase):
     def test_product_available_by_stock(self):
         """ If no orders have been made, the product is still available. """
         product = ProductFactory(stock_amount=10)
-        self.assertEqual(product.left_in_stock(), 10)
-        self.assertTrue(product.is_available)
+        self.assertEqual(product.left_in_stock, 10)
+        self.assertTrue(product.is_available())
 
     def test_product_not_available_by_stock(self):
         """ If max orders have been made, the product is NOT available. """
@@ -26,5 +29,48 @@ class ProductAvailabilityTest(TestCase):
             order.paid = True
             order.save()
 
-        self.assertEqual(product.left_in_stock(), 0)
+        self.assertEqual(product.left_in_stock, 0)
+        self.assertFalse(product.is_stock_available)
         self.assertFalse(product.is_available())
+
+    def test_product_available_by_time(self):
+        """ The product is available if now is in the right timeframe. """
+        product = ProductFactory()
+        # The factory defines the timeframe as now and 31 days forward.
+        self.assertTrue(product.is_time_available)
+        self.assertTrue(product.is_available())
+
+    def test_product_not_available_by_time(self):
+        """ The product is not available if now is outside the timeframe. """
+        available_in = DateTimeTZRange(
+            lower=timezone.now() - timezone.timedelta(5),
+            upper=timezone.now() - timezone.timedelta(1)
+        )
+        product = ProductFactory(available_in=available_in)
+        # The factory defines the timeframe as now and 31 days forward.
+        self.assertFalse(product.is_time_available)
+        self.assertFalse(product.is_available())
+
+    def test_product_is_not_available_yet(self):
+        """ The product is not available because we are before lower bound. """
+        available_in = DateTimeTZRange(
+            lower=timezone.now() + timezone.timedelta(5)
+        )
+        product = ProductFactory(available_in=available_in)
+        # Make sure there is no upper - just in case.
+        self.assertEqual(product.available_in.upper, None)
+        # The factory defines the timeframe as now and 31 days forward.
+        self.assertFalse(product.is_time_available)
+        self.assertFalse(product.is_available())
+
+    def test_product_is_available_from_now_on(self):
+        """ The product is available because we are after lower bound. """
+        available_in = DateTimeTZRange(
+            lower=timezone.now() - timezone.timedelta(1)
+        )
+        product = ProductFactory(available_in=available_in)
+        # Make sure there is no upper - just in case.
+        self.assertEqual(product.available_in.upper, None)
+        # The factory defines the timeframe as now and 31 days forward.
+        self.assertTrue(product.is_time_available)
+        self.assertTrue(product.is_available())