* available_count for Gift

store/migrations/0049_gift_available_count.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.2.2 on 2023-11-22 22:28
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('store', '0048_globalsettings_yuan_rate_commission_and_more'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='gift',
+            name='available_count',
+            field=models.PositiveSmallIntegerField(default=0, verbose_name='Доступное количество'),
+        ),
+    ]

store/models.py

@@ -260,6 +260,7 @@ class Gift(models.Model):
     name = models.CharField('Название', max_length=100)
     image = models.ImageField('Фото', upload_to=Image.TYPE_TO_UPLOAD_PATH[Image.GIFT], null=True, blank=True)
     min_price = models.DecimalField('Минимальная цена в юанях', help_text='от какой суммы доступен подарок', max_digits=10, decimal_places=2, default=0)
+    available_count = models.PositiveSmallIntegerField('Доступное количество', default=0)
 
     def __str__(self):
         return self.name
@@ -636,6 +637,18 @@ class Checklist(models.Model):
             if not self.preview_image:
                 self.generate_preview()
 
+            # Update available gifts count
+            if self.gift != old_obj.gift:
+                # Decrement new gift
+                if self.gift:
+                    self.gift.available_count = max(self.gift.available_count - 1, 0)
+                    self.gift.save()
+
+                # Increment new gift
+                if old_obj.gift:
+                    old_obj.gift.available_count = max(old_obj.gift.available_count + 1, 0)
+                    old_obj.gift.save()
+
         # Save price details to snapshot
         if self.price_snapshot_id:
             # Status updated from other statuses back to DRAFT

store/serializers.py

@@ -200,8 +200,13 @@ class AnonymousUserChecklistSerializer(ChecklistSerializer):
 
     def validate(self, attrs):
         gift = attrs.get('gift')
-        if gift is not None and self.instance.price_yuan < gift.min_price:
-            raise CRMException("Can't add gift: price of order < min_price of gift")
+        if gift is not None:
+            if self.instance.price_yuan < gift.min_price:
+                raise CRMException("Can't add gift: price of order < min_price of gift")
+
+            if gift.available_count == 0:
+                raise CRMException("Gift is not available")
+
         return attrs