Feat/scoped presentation coupons

shop/admin.py

@@ -6,7 +6,12 @@
 from shop.models import Presenter, Presentation, Participation, Coupon, Payment, PresentationTag
 
 admin.site.register(Presenter)
-admin.site.register(PresentationTag)
+
+
+@admin.register(PresentationTag)
+class PresentationTagAdmin(admin.ModelAdmin):
+    list_display = ('en_name', 'fa_name', 'color')
+    search_fields = ('en_name', 'fa_name')
 
 @admin.register(Payment)
 class PaymentAdmin(admin.ModelAdmin):
@@ -15,12 +20,14 @@ class PaymentAdmin(admin.ModelAdmin):
 @admin.register(Participation)
 class ParticipationAdmin(admin.ModelAdmin):
     search_fields = ['user__phone_number']
-    list_display = ['__str__','payment_state', 'presentation__cost']
+    list_display = ['__str__', 'payment_state', 'is_capacity_exempt', 'presentation__cost']
+    list_filter = ['payment_state', 'is_capacity_exempt']
 
 
 @admin.register(Coupon)
 class CouponAdmin(admin.ModelAdmin):
-    list_display = ('name', 'used')
+    list_display = ('name', 'percentage', 'count', 'preserve_capacity', 'used')
+    filter_horizontal = ('eligible_presentations',)
 
     def used(self, obj):
         return Payment.objects.filter(payment_state="COMPLETED", coupon=obj).count()

shop/migrations/0019_bilingual_presentation_tags.py

@@ -0,0 +1,36 @@
+from django.db import migrations, models
+
+
+def populate_persian_names(apps, schema_editor):
+    PresentationTag = apps.get_model("shop", "PresentationTag")
+    translations = {
+        "Online": "آنلاین",
+        "In-Person": "حضوری",
+        "Beginner": "مبتدی",
+        "Intermediate": "متوسط",
+        "Advanced": "پیشرفته",
+    }
+    for tag in PresentationTag.objects.all():
+        tag.fa_name = translations.get(tag.en_name, tag.en_name)
+        tag.save(update_fields=["fa_name"])
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("shop", "0018_launch_safety_constraints"),
+    ]
+
+    operations = [
+        migrations.RenameField(
+            model_name="presentationtag",
+            old_name="name",
+            new_name="en_name",
+        ),
+        migrations.AddField(
+            model_name="presentationtag",
+            name="fa_name",
+            field=models.CharField(default="", max_length=63),
+            preserve_default=False,
+        ),
+        migrations.RunPython(populate_persian_names, migrations.RunPython.noop),
+    ]

shop/migrations/0020_coupon_eligible_presentations_and_more.py

@@ -0,0 +1,38 @@
+# Generated by Django 5.1.5 on 2026-10-07 05:06
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('shop', '0019_bilingual_presentation_tags'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='coupon',
+            name='eligible_presentations',
+            field=models.ManyToManyField(blank=True, help_text='Leave empty to apply this coupon to the whole cart.', related_name='coupons', to='shop.presentation'),
+        ),
+        migrations.AddField(
+            model_name='coupon',
+            name='preserve_capacity',
+            field=models.BooleanField(default=False, help_text="When enabled, registrations discounted by this coupon do not reduce the selected presentations' remaining capacity."),
+        ),
+        migrations.AddField(
+            model_name='participation',
+            name='is_capacity_exempt',
+            field=models.BooleanField(default=False, help_text='Completed registrations with this flag do not reduce remaining capacity.'),
+        ),
+        migrations.AddField(
+            model_name='payment',
+            name='coupon_participations',
+            field=models.ManyToManyField(blank=True, help_text="Snapshot of participations to which this payment's coupon applied.", related_name='coupon_payments', to='shop.participation'),
+        ),
+        migrations.AddField(
+            model_name='payment',
+            name='coupon_preserves_capacity',
+            field=models.BooleanField(default=False, help_text="Snapshot of the coupon's capacity behavior when checkout started."),
+        ),
+    ]

shop/models.py

@@ -36,11 +36,12 @@ def __str__(self):
         return f'{self.last_name} {self.first_name}'
 
 class PresentationTag(models.Model):
-    name = models.CharField(max_length=63)
+    en_name = models.CharField(max_length=63)
+    fa_name = models.CharField(max_length=63)
     color = ColorField(default="#FA175C")
 
     def __str__(self):
-        return self.name
+        return f"{self.fa_name} / {self.en_name}"
 
 
 class Presentation(models.Model):
@@ -76,6 +77,7 @@ def get_remained_capacity(self):
         # seat at the same time.
         committed = Participation.objects.filter(
             presentation=self,
+            is_capacity_exempt=False,
         ).filter(
             models.Q(payment_state="COMPLETED")
             | models.Q(
@@ -98,6 +100,10 @@ class Participation(models.Model):
     user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='participations')
     presentation = models.ForeignKey(Presentation, on_delete=models.CASCADE, related_name='participations')
     payment_state = models.CharField(choices=PAYMENT_STATES, default="PENDING", max_length=10)
+    is_capacity_exempt = models.BooleanField(
+        default=False,
+        help_text="Completed registrations with this flag do not reduce remaining capacity.",
+    )
 
     class Meta:
         constraints = [
@@ -115,6 +121,19 @@ class Coupon(models.Model):
     name = models.CharField(max_length=50, primary_key=True, help_text="Don't use / in the name.")
     count = models.PositiveIntegerField()
     percentage = models.IntegerField(default=0.0, help_text='Enter a number between 0 to 100.')
+    eligible_presentations = models.ManyToManyField(
+        Presentation,
+        blank=True,
+        related_name="coupons",
+        help_text="Leave empty to apply this coupon to the whole cart.",
+    )
+    preserve_capacity = models.BooleanField(
+        default=False,
+        help_text=(
+            "When enabled, registrations discounted by this coupon do not reduce "
+            "the selected presentations' remaining capacity."
+        ),
+    )
 
     def __str__(self):
         return self.name
@@ -143,6 +162,16 @@ class Payment(models.Model):
     created_date = models.DateTimeField(auto_now_add=True)
     verified_date = models.DateTimeField(null=True, blank=True)
     coupon = models.ForeignKey(Coupon, on_delete=models.SET_NULL, default=None, null=True, blank=True)
+    coupon_participations = models.ManyToManyField(
+        Participation,
+        blank=True,
+        related_name="coupon_payments",
+        help_text="Snapshot of participations to which this payment's coupon applied.",
+    )
+    coupon_preserves_capacity = models.BooleanField(
+        default=False,
+        help_text="Snapshot of the coupon's capacity behavior when checkout started.",
+    )
     accessories = models.ManyToManyField(Accessory, "payment_accessories")
     is_competition_payment = models.BooleanField(default=False)
 

shop/serializers.py

@@ -8,9 +8,12 @@ class Meta:
         fields = ['first_name', 'last_name', 'email', 'description', 'avatar', 'linkedin']
 
 class PresentationTagSerializer(serializers.ModelSerializer):
+    # Keep the legacy field until all deployed frontend clients use en_name.
+    name = serializers.CharField(source='en_name', read_only=True)
+
     class Meta:
         model = PresentationTag
-        fields = ['name', 'color']
+        fields = ['name', 'en_name', 'fa_name', 'color']
 
 class PresentationSerializer(serializers.ModelSerializer):
     remained_capacity = serializers.SerializerMethodField()
@@ -51,7 +54,9 @@ class Meta:
 class CouponSerializer(serializers.ModelSerializer):
     is_valid = serializers.SerializerMethodField()
     class Meta:
-        fields = ['percentage', 'is_valid']
+        fields = [
+            'percentage', 'is_valid', 'eligible_presentations', 'preserve_capacity',
+        ]
         model = Coupon
 
     def get_is_valid(self, obj):