#207 Context classes (#212)

* Implement ProductBrands class

* Implement ProductImages class

* Create tests: ProductsContext and TagsContext. Fix a lot of code.

* Apply the review's fixes

catalog/models.py

@@ -134,7 +134,7 @@ def tagged(self, tags):
         # See docs for details:
         # https://www.postgresql.org/docs/10/static/sql-select.html#SQL-DISTINCT
         # https://docs.djangoproject.com/en/2.1/ref/models/querysets/#django.db.models.query.QuerySet.distinct
-        return self.filter(tags__in=self._tags).distinct()
+        return self.filter(tags__in=tags).distinct()
 
 
 class ProductManager(models.Manager.from_queryset(ProductQuerySet)):
@@ -259,6 +259,7 @@ def get_group_tags_pairs(self) -> List[Tuple[TagGroup, List['Tag']]]:
     def get_brands(self, products: Iterable[AbstractProduct]) -> Dict[AbstractProduct, 'Tag']:
         brand_tags = (
             self.filter(group__name=settings.BRAND_TAG_GROUP_NAME)
+            .filter_by_products(products)
             .prefetch_related('products')
             .select_related('group')
         )

catalog/newcontext/__init__.py

@@ -1 +1,3 @@
-# @todo #183:120m Implement Page, PaginatedProducts, ProductBrands, ProductsImages context classes.
+# @todo #207:120m Implement Page, PaginatedProducts context classes.
+from . import products, tags
+from .context import Context, Contexts, ModelContext, Products, Tags

catalog/newcontext/products.py

@@ -1,11 +1,24 @@
 import typing
 
+from django.conf import settings
 from django.db.models import QuerySet
 
-from catalog.newcontext.context import Products, Tags
+from catalog.newcontext.context import Context, Products, Tags
 from catalog.models import AbstractCategory
 
 
+class SortingOption:
+    def __init__(self, index=0):
+        options = settings.CATEGORY_SORTING_OPTIONS[index]
+        self.label = options['label']
+        self.field = options['field']
+        self.direction = options['direction']
+
+    @property
+    def directed_field(self):
+        return self.direction + self.field
+
+
 class ActiveProducts(Products):
 
     def __init__(self, products: Products):
@@ -19,7 +32,7 @@ class OrderedProducts(Products):
 
     def __init__(self, products: Products, req_kwargs):
         self._products = products
-        self._sorting_index = self._req_kwargs.get('sorting', 0)
+        self._sorting_index = req_kwargs.get('sorting', 0)
 
     def qs(self):
         return self._products.qs().order_by(
@@ -43,9 +56,9 @@ def qs(self):
         return self._products.qs().get_category_descendants(self._category)
 
 
-class ProductsByTags(Products):
+class TaggedProducts(Products):
 
-    def __init__(self, products: Products, tags_context: Tags):
+    def __init__(self, products: Products, tags: Tags):
         self._products = products
         self._tags = tags
 
@@ -55,3 +68,45 @@ def qs(self):
             return self._products.qs().tagged(tags)
         else:
             return self._products.qs()
+
+
+class ProductBrands(Context):
+
+    def __init__(self, products: Products, tags: Tags):
+        self._products = products
+        self._tags = tags
+
+    def context(self):
+        products_qs = self.products.qs()
+        brands = self.tags.qs().get_brands(products_qs)
+
+        product_brands = {
+            product.id: brands.get(product)
+            for product in products_qs
+        }
+
+        return {
+            'product_brands': product_brands,
+        }
+
+
+class ProductImages(Context):
+
+    def __init__(self, products: Products, images: QuerySet):
+        self._products = products
+        self._images = images
+
+    def context(self):
+        page_product_map = {
+            product.page: product
+            for product in self._products.qs()
+        }
+        images = self._images.get_main_images_by_pages(page_product_map.keys())
+        product_images = {
+            product: images.get(page)
+            for page, product in page_product_map.items()
+        }
+
+        return {
+            'product_images': product_images,
+        }

catalog/newcontext/tags.py

@@ -1,6 +1,7 @@
 from catalog.newcontext.context import Context, Tags, Products
 
 from django.db.models import QuerySet
+from django.http import Http404
 
 
 class GroupedTags(Context):
@@ -23,7 +24,7 @@ def __init__(self, tags: Tags, req_kwargs):
     def qs(self):
         tags = self._tags.qs()
         if not self._raw_tags:
-            tags.none()
+            return tags.none()
         return tags.parsed(self._raw_tags)
 
 
@@ -35,5 +36,5 @@ def __init__(self, tags: Tags):
     def qs(self):
         tags = self._tags.qs()
         if not tags.exists():
-            raise http.Http404('No such tag.')
+            raise Http404('No such tag.')
         return tags

images/models.py

@@ -25,7 +25,7 @@ def get_main_images_by_pages(self, pages) -> dict:
 
         images_query = (
             self.get_queryset()
-                .filter(object_id__in=[page.id for page in pages], is_main=True)
+            .filter(object_id__in=[page.id for page in pages], is_main=True)
         )
 
         if not images_query.exists():

tests/catalog/test_context.py

@@ -0,0 +1,70 @@
+import unittest
+
+from django.test import TestCase, override_settings
+from django.http import Http404
+
+from catalog import newcontext as context
+from tests.catalog import models as catalog_models
+
+
+def mocked_ctx(qs_attrs=None, context_attrs=None):
+    ctx = unittest.mock.Mock()
+    ctx.qs.return_value = unittest.mock.Mock(**(qs_attrs or {}))
+    ctx.context.return_value = unittest.mock.Mock(**(context_attrs or {}))
+
+    return ctx
+
+
+class ProductsContext(TestCase):
+
+    fixtures = ['catalog.json']
+
+    def products_ctx(self, qs=None) -> context.context.Products:
+        return context.context.Products(qs or catalog_models.MockProduct.objects.all())
+
+    def test_ordered_products(self):
+        order_by = 'price'
+        with override_settings(CATEGORY_SORTING_OPTIONS={
+            1: {'label': order_by, 'field': order_by, 'direction': ''}
+        }):
+            products_ctx = self.products_ctx()
+            self.assertEqual(
+                list(products_ctx.qs().order_by(order_by)),
+                list(context.products.OrderedProducts(products_ctx, {'sorting': 1}).qs()),
+            )
+
+    def test_tagged_products(self):
+        products_ctx = mocked_ctx()
+        context.products.TaggedProducts(
+            products_ctx, mocked_ctx(qs_attrs={'exists.return_value': True}),
+        ).qs()
+
+        self.assertTrue(products_ctx.qs().tagged.called)
+
+    def test_non_tagged_products(self):
+        """If there are no tags, then products don't changed."""
+        products_ctx = mocked_ctx()
+        context.products.TaggedProducts(
+            products_ctx, mocked_ctx(qs_attrs={'exists.return_value': False}),
+        ).qs()
+
+        self.assertFalse(products_ctx.qs().tagged.called)
+
+
+class TagsContext(TestCase):
+
+    def test_parsed_tags(self):
+        tags_ctx = mocked_ctx()
+        context.tags.ParsedTags(tags_ctx, {'tags': 'test'}).qs()
+        self.assertTrue(tags_ctx.qs().parsed.called)
+
+    def test_unparsed_tags(self):
+        self.assertFalse(
+            context.tags.ParsedTags(
+                mocked_ctx(qs_attrs={'none.return_value': []}), {},
+            ).qs()
+        )
+
+    def test_404_check_tags(self):
+        with self.assertRaises(Http404):
+            context.tags.Checked404Tags(mocked_ctx(qs_attrs={'exists.return_value': False})).qs()