refactor

admin_panel/models/products.py

@@ -0,0 +1,148 @@
+from django.db import models, transaction, connection
+from django.db.models import Sum
+
+
+class ProductCategory(models.Model):
+    category_name = models.CharField(max_length=50)
+
+    def __str__(self):
+        return self.category_name
+
+
+class Product(models.Model):
+    class Meta:
+        permissions = [
+            ("ViewProduct", "ViewProduct"),
+        ]
+    ProductCategory = models.ForeignKey(ProductCategory, on_delete=models.CASCADE)
+    product_name = models.CharField(max_length=50)
+    product_price = models.IntegerField()
+    year = models.IntegerField(default=1400)
+    createdDT = models.DateTimeField(auto_now_add=True)
+    changeDT = models.DateTimeField(auto_now=True)
+
+    def __str__(self):
+        return self.product_name
+
+
+class ProductInStore(models.Model):
+    class Meta:
+        permissions = [
+            ("ViewProductInStore", "ViewProductInStore"),
+            ("EditProductInStore", "EditProductInStore"),
+            ("OnlyAnbar", "OnlyAnbar"),
+        ]
+    class MovementType(models.TextChoices):
+        SALE = 'SALE', 'فروش عادی'
+        WARRANTY = 'WARRANTY', 'گارانتی'
+        PROMOTION = 'PROMOTION', 'اشانتیون'
+        TRANSFER = 'TRANSFER', 'انتقال'
+        INITIAL = 'INITIAL', 'موجودی اولیه'
+        DIRECT_IN = 'DIRECT_IN', 'ورود دستی'
+        DIRECT_OUT = 'DIRECT_OUT', 'خروج دستی'
+        RETURN = 'RETURN', 'برگشت از فروش'
+        ERROR_CORRECTION = 'ERROR_CORRECTION', 'اصلاح خطای ثبت'
+
+    StoreRoom = models.ForeignKey('StoreRoom', on_delete=models.CASCADE)
+    Product = models.ForeignKey(Product, on_delete=models.CASCADE)
+    s_in = models.IntegerField(default=0)
+    s_out = models.IntegerField(default=0)
+    current_stock_at_time = models.IntegerField(default=0, help_text="موجودی انبار در لحظه این تراکنش")
+    desc = models.CharField(max_length=50, default='')
+    year = models.IntegerField(default=1400)
+    createdDT = models.DateTimeField(auto_now_add=True)
+    changeDT = models.DateTimeField(auto_now=True)
+
+    # تغییر بسیار مهم استراتژیک: تبدیل CASCADE به PROTECT
+    # هیچکس نمی‌تواند فاکتوری که کالا از انبار خارج کرده را از دیتابیس پاک کند!
+    factor = models.ForeignKey('Factor', on_delete=models.PROTECT, null=True, blank=True)
+
+    movement_type = models.CharField(
+        max_length=20,
+        choices=MovementType.choices,
+        db_index=True,
+        null=True,
+        blank=True
+    )
+
+    def __str__(self):
+        return f"{self.Product.product_name} - In: {self.s_in} Out: {self.s_out}"
+
+    # متدهای save و delete دقیقاً همان کدهای بی‌نقص و پرسرعتی هستند که در پیام قبل تایید کردیم
+    def save(self, *args, **kwargs):
+        from .store import ProductStockHistory
+
+        try:
+            self.s_in = int(self.s_in or 0)
+            self.s_out = int(self.s_out or 0)
+        except (ValueError, TypeError):
+            self.s_in, self.s_out = 0, 0
+
+        is_created = self.pk is None
+
+        with transaction.atomic():
+            qs_lock = ProductInStore.objects.filter(StoreRoom=self.StoreRoom, Product=self.Product)
+            if connection.features.has_select_for_update:
+                qs_lock = qs_lock.select_for_update()
+            list(qs_lock)
+
+            if not is_created:
+                old_instance = ProductInStore.objects.get(pk=self.pk)
+                old_balance = old_instance.s_in - old_instance.s_out
+                new_balance = self.s_in - self.s_out
+                change_amount = new_balance - old_balance
+                description = self.desc or f"ویرایش تراکنش: {self.desc}"
+            else:
+                change_amount = self.s_in - self.s_out
+                description = self.desc or "ثبت تراکنش جدید انبار"
+
+            super().save(*args, **kwargs)
+
+            totals = ProductInStore.objects.filter(StoreRoom=self.StoreRoom, Product=self.Product).aggregate(
+                total_in=Sum('s_in'),
+                total_out=Sum('s_out')
+            )
+            total_in = totals['total_in'] or 0
+            total_out = totals['total_out'] or 0
+            current_stock = total_in - total_out
+
+            ProductInStore.objects.filter(pk=self.pk).update(current_stock_at_time=current_stock)
+            self.current_stock_at_time = current_stock
+
+            ProductStockHistory.objects.create(
+                store_room=self.StoreRoom,
+                product=self.Product,
+                quantity_changed=change_amount,
+                current_stock=current_stock,
+                desc=description
+            )
+
+    def delete(self, *args, **kwargs):
+        from .store import ProductStockHistory
+
+        store_room = self.StoreRoom
+        product = self.Product
+        change_amount = -(int(self.s_in or 0) - int(self.s_out or 0))
+        description = f"حذف دستی تراکنش انبار: {self.desc}"
+
+        with transaction.atomic():
+            qs_lock = ProductInStore.objects.filter(StoreRoom=store_room, Product=product)
+            if connection.features.has_select_for_update:
+                qs_lock = qs_lock.select_for_update()
+            list(qs_lock)
+
+            super().delete(*args, **kwargs)
+
+            totals = ProductInStore.objects.filter(StoreRoom=store_room, Product=product).aggregate(
+                total_in=Sum('s_in'),
+                total_out=Sum('s_out')
+            )
+            current_stock = (totals['total_in'] or 0) - (totals['total_out'] or 0)
+
+            ProductStockHistory.objects.create(
+                store_room=store_room,
+                product=product,
+                quantity_changed=change_amount,
+                current_stock=current_stock,
+                desc=description
+            )