feat(prices): new stats endpoint

open_prices/api/prices/serializers.py

@@ -50,3 +50,10 @@ class PriceUpdateSerializer(serializers.ModelSerializer):
     class Meta:
         model = Price
         fields = Price.UPDATE_FIELDS
+
+
+class PriceStatsSerializer(serializers.Serializer):
+    price__count = serializers.IntegerField()
+    price__min = serializers.DecimalField(max_digits=10, decimal_places=2)
+    price__max = serializers.DecimalField(max_digits=10, decimal_places=2)
+    price__avg = serializers.DecimalField(max_digits=10, decimal_places=2)

open_prices/api/prices/tests.py

@@ -1,10 +1,13 @@
+from decimal import Decimal
+
 from django.test import TestCase
 from django.urls import reverse
 
 from open_prices.locations.models import Location
 from open_prices.prices import constants as price_constants
 from open_prices.prices.factories import PriceFactory
 from open_prices.prices.models import Price
+from open_prices.products.factories import ProductFactory
 from open_prices.products.models import Product
 from open_prices.proofs import constants as proof_constants
 from open_prices.proofs.factories import ProofFactory
@@ -491,3 +494,42 @@ def test_price_delete(self):
         self.assertEqual(
             Price.objects.filter(owner=self.user_session_1.user.user_id).count(), 0
         )
+
+
+class PriceStatsApiTest(TestCase):
+    @classmethod
+    def setUpTestData(cls):
+        cls.url = reverse("api:prices-stats")
+        cls.product = ProductFactory()
+        PriceFactory(
+            product_code=cls.product.code,
+            price=15,
+            price_is_discounted=True,
+            price_without_discount=20,
+        )
+        PriceFactory(product_code=cls.product.code, price=25)
+        PriceFactory(product_code=cls.product.code, price=30)
+        PriceFactory(
+            product_code=None,
+            category_tag="en:apples",
+            price=2,
+            price_per=price_constants.PRICE_PER_KILOGRAM,
+        )
+
+    def test_price_stats(self):
+        response = self.client.get(self.url)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data["price__count"], 4)
+        self.assertEqual(response.data["price__min"], 2.00)
+        self.assertEqual(response.data["price__max"], 30.00)
+        self.assertEqual(response.data["price__avg"], Decimal(18.00))
+        url = self.url + "?price_is_discounted=False"
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data["price__count"], 3)
+        self.assertEqual(response.data["price__avg"], Decimal(19.00))
+        url = self.url + f"?price_is_discounted=false&product_code={self.product.code}"
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data["price__count"], 2)
+        self.assertEqual(response.data["price__avg"], Decimal(27.50))

open_prices/api/prices/views.py

@@ -1,5 +1,7 @@
 from django_filters.rest_framework import DjangoFilterBackend
+from drf_spectacular.utils import extend_schema
 from rest_framework import filters, mixins, status, viewsets
+from rest_framework.decorators import action
 from rest_framework.permissions import IsAuthenticatedOrReadOnly
 from rest_framework.request import Request
 from rest_framework.response import Response
@@ -8,6 +10,7 @@
 from open_prices.api.prices.serializers import (
     PriceCreateSerializer,
     PriceFullSerializer,
+    PriceStatsSerializer,
     PriceUpdateSerializer,
 )
 from open_prices.common.authentication import CustomAuthentication
@@ -63,3 +66,9 @@ def create(self, request: Request, *args, **kwargs):
         return Response(
             self.serializer_class(price).data, status=status.HTTP_201_CREATED
         )
+
+    @extend_schema(responses=PriceStatsSerializer, filters=True)
+    @action(detail=False, methods=["GET"])
+    def stats(self, request: Request) -> Response:
+        qs = self.filter_queryset(self.get_queryset())
+        return Response(qs.calculate_stats(), status=200)

open_prices/api/views.py

@@ -12,4 +12,4 @@ class StatusView(APIView):
 
     @extend_schema(responses=StatusSerializer, tags=["status"])
     def get(self, request: Request) -> Response:
-        return Response({"status": "running"})
+        return Response({"status": "running"}, status=200)