Modified quantity logic

StockSeeker/serializers.py

@@ -1,7 +1,7 @@
 from rest_framework import serializers
 from .models import *
 from django.contrib.auth.models import User
-
+from django.db.models import F
 
 class UserSerializer(serializers.ModelSerializer):
     password = serializers.CharField(write_only=True)
@@ -50,38 +50,38 @@ class ProductSerializer(serializers.ModelSerializer):
         model = Product
         fields = ["id", "name", "description", "quantity", "creation_date", "modification_date", "user","stock_limit","alert_enabled","is_stock_low","image","warehouses",]
 
+    #GERER les nombres négatifs impossible #
     def create(self, validated_data):
         warehouses = validated_data.pop('warehouses', [])
         product = Product.objects.create(**validated_data)
         product.warehouses.set(warehouses)
 
         for warehouse in product.warehouses.all():
-            print(f'capacité actuelle {warehouse.actual_capacity}, - {product.quantity}')
-            warehouse.actual_capacity -= product.quantity
-            warehouse.save()
+            warehouse.actual_capacity = F('actual_capacity') - product.quantity
+            warehouse.save(update_fields=['actual_capacity'])
+
         return product
     
     def update(self,instance, validated_data):
-        product = Product.objects.get(id=instance.id)
         instance.name = validated_data.get("name", instance.name)
         instance.description = validated_data.get("description", instance.description)
-        instance.quantity = validated_data.get("quantity", instance.quantity)
-        instance.save()
+        new_quantity = validated_data.get("quantity", instance.quantity)
 
-        for warehouse in product.warehouses.all():
-            warehouse.actual_capacity = warehouse.max_capacity
-            warehouse.actual_capacity -= instance.quantity
-            warehouse.save()
+        quantity_difference = new_quantity - instance.quantity
+        instance.quantity = new_quantity
+        instance.save()
+        instance.refresh_from_db()
+
+        for warehouse in instance.warehouses.all():
+            warehouse.actual_capacity = F('actual_capacity') - quantity_difference
+            warehouse.save(update_fields=['actual_capacity'])
         return instance
     
     def destroy(self, instance):
-        product = Product.objects.get(id=instance.id)
-        
-        for warehouse in product.warehouses.all():
-            warehouse.actual_capacity += instance.quantity
-            warehouse.save()
+        for warehouse in instance.warehouses.all():
+            warehouse.actual_capacity = F('actual_capacity') + instance.quantity
+            warehouse.save(update_fields=['actual_capacity'])
         instance.delete()
-        return instance
     
     def validate_warehouses(self, value):
         if not value:
@@ -96,13 +96,30 @@ class ProductSerializer(serializers.ModelSerializer):
     def get_is_stock_low(self, obj):
         return obj.alert_enabled and obj.stock_limit is not None and obj.quantity < obj.stock_limit
     
+
 class WarehouseSerializer(serializers.ModelSerializer):
     user = serializers.PrimaryKeyRelatedField(read_only=True)
 
+    def update(self, instance, validated_data):
+        old_max_capacity = instance.max_capacity
+        instance.name = validated_data.get("name", instance.name)
+        instance.location = validated_data.get("location", instance.location)
+        new_max_capacity = validated_data.get("max_capacity", instance.max_capacity)
+        capacity_difference = new_max_capacity - old_max_capacity
+
+        instance.actual_capacity = F('actual_capacity') + capacity_difference
+        instance.max_capacity = new_max_capacity
+
+        instance.save()
+        instance.refresh_from_db()
+
+        return instance
+    
     class Meta:
         model = Warehouse
         fields = ["id", "name", "location", "max_capacity","user","actual_capacity"]
     
+    
     def validate_max_capacity(self, value):
         if value < 0:
             raise serializers.ValidationError("La capacité maximale ne peut pas être négative.")

StockSeeker/views.py

@@ -53,6 +53,10 @@ class ProductView(viewsets.ModelViewSet):
     def perform_update(self, serializer):
         serializer.save(user=self.request.user)
 
+    def perform_destroy(self, instance):
+        serializer = self.get_serializer(instance)
+        serializer.destroy(instance)
+        
     def get_queryset(self):
         return Product.objects.filter(user_id=self.request.user)