feat: add Products form to admin

purchase/migrations/0002_purchasableproduct.py

@@ -0,0 +1,26 @@
+# Generated by Django 6.0.4 on 2026-05-18 14:14
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('purchase', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='PurchasableProduct',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=255)),
+                ('description', models.TextField(blank=True)),
+                ('price_cents', models.PositiveIntegerField(help_text='Price in cents')),
+                ('currency', models.CharField(default='usd', max_length=10)),
+                ('stripe_product_id', models.CharField(blank=True, max_length=255, null=True)),
+                ('stripe_price_id', models.CharField(blank=True, max_length=255, null=True)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+            ],
+        ),
+    ]

purchase/migrations/0003_alter_purchasableproduct_currency.py

@@ -0,0 +1,18 @@
+# Generated by Django 6.0.4 on 2026-05-18 14:54
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('purchase', '0002_purchasableproduct'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='purchasableproduct',
+            name='currency',
+            field=models.CharField(default='pln', max_length=10),
+        ),
+    ]

purchase/migrations/0004_purchasableproduct_course.py

@@ -0,0 +1,21 @@
+# Generated by Django 6.0.4 on 2026-05-18 15:05
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('home', '0023_eventindexpage'),
+        ('purchase', '0003_alter_purchasableproduct_currency'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='purchasableproduct',
+            name='course',
+            field=models.OneToOneField(default=0, on_delete=django.db.models.deletion.CASCADE, related_name='purchasable_product', to='home.coursepage'),
+            preserve_default=False,
+        ),
+    ]

purchase/models.py

@@ -2,9 +2,11 @@ import logging as lg
 import os
 
 import requests
+import stripe
 from django.conf import settings
 from django.contrib.auth.models import Group
 from django.db import models
+from wagtail.admin.panels import FieldPanel
 
 GITEA_ORG_NAME = "Studio77"
 logger = lg.getLogger(__name__)
@@ -132,3 +134,195 @@ class CoursePurchase(models.Model):
                 f"Adding user {self.user} to group {group_name} for course {self.course.title}"
             )
             self.add_to_gitea_team()
+
+
+class PurchasableProduct(models.Model):
+    """A product that can be purchased. When created it will create a Stripe Product and Price.
+
+    On delete it will try to deactivate the Price and delete the Product in Stripe.
+    The code is defensive: if STRIPE_API_KEY is not configured the model will still work locally.
+    """
+
+    name = models.CharField(max_length=255)
+    description = models.TextField(blank=True)
+    price_cents = models.PositiveIntegerField(help_text="Price in cents")
+    currency = models.CharField(
+        max_length=10, default=getattr(settings, "STRIPE_DEFAULT_CURRENCY", "pln")
+    )
+    stripe_product_id = models.CharField(max_length=255, blank=True, null=True)
+    stripe_price_id = models.CharField(max_length=255, blank=True, null=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    panels = [
+        FieldPanel("price_cents"),
+        FieldPanel("currency"),
+    ]
+
+    def __str__(self):
+        return f"{self.name} ({self.price_cents / 100:.2f} {self.currency.upper()})"
+
+    def save(self, *args, **kwargs):
+        """Save locally first to ensure we have a PK, then create or update Stripe product/price if needed.
+
+        Behavior:
+        - On create: create Stripe Product and Price (if STRIPE_SECRET_KEY is set).
+        - On update:
+            - If name or description changed -> update Stripe Product.
+            - If price_cents or currency changed -> create a new Stripe Price and deactivate the old one, then update stripe_price_id.
+        - If STRIPE_SECRET_KEY is not configured the model will still work locally.
+        """
+        # Capture whether this is a new object and the previous state (if any)
+        is_new = self.pk is None
+        previous = None
+        if not is_new:
+            try:
+                previous = self.__class__.objects.get(pk=self.pk)
+            except self.__class__.DoesNotExist:
+                previous = None
+
+        # Persist local changes first so we have an id
+        super().save(*args, **kwargs)
+
+        stripe_api_key = getattr(
+            settings, "STRIPE_SECRET_KEY", os.getenv("STRIPE_SECRET_KEY")
+        )
+        if not stripe_api_key:
+            logger.debug(
+                "STRIPE_SECRET_KEY not set, skipping Stripe product/price creation/update"
+            )
+            return
+
+        stripe.api_key = stripe_api_key
+        try:
+            changed_fields = []
+
+            # Create Stripe Product if missing
+            if not self.stripe_product_id:
+                prod = stripe.Product.create(
+                    name=self.name,
+                    description=self.description or None,
+                    metadata={"local_id": str(self.id)},
+                )
+                self.stripe_product_id = prod.id
+                changed_fields.append("stripe_product_id")
+                logger.info(
+                    f"Created Stripe product {self.stripe_product_id} for PurchasableProduct {self.id}"
+                )
+
+            # If we don't have a price id, create one
+            if not self.stripe_price_id:
+                price = stripe.Price.create(
+                    product=self.stripe_product_id,
+                    unit_amount=self.price_cents,
+                    currency=self.currency.lower(),
+                )
+                self.stripe_price_id = price.id
+                changed_fields.append("stripe_price_id")
+                logger.info(
+                    f"Created Stripe price {self.stripe_price_id} for PurchasableProduct {self.id}"
+                )
+
+            # If this is an update (we had previous state) perform updates
+            if previous:
+                # Update product metadata/name/description if they changed
+                try:
+                    if (previous.name != self.name) or (
+                        previous.description != self.description
+                    ):
+                        stripe.Product.modify(
+                            self.stripe_product_id,
+                            name=self.name,
+                            description=self.description or None,
+                        )
+                        logger.info(
+                            f"Updated Stripe product {self.stripe_product_id} for PurchasableProduct {self.id}"
+                        )
+                except Exception:
+                    logger.exception(
+                        f"Failed to update Stripe product {self.stripe_product_id} for PurchasableProduct {self.id}"
+                    )
+
+                # If price or currency changed, create a new Price and deactivate the old one
+                try:
+                    prev_currency = (previous.currency or "").lower()
+                    curr_currency = (self.currency or "").lower()
+                    if (previous.price_cents != self.price_cents) or (
+                        prev_currency != curr_currency
+                    ):
+                        # Create new price for the same product
+                        new_price = stripe.Price.create(
+                            product=self.stripe_product_id,
+                            unit_amount=self.price_cents,
+                            currency=self.currency.lower(),
+                        )
+                        # Attempt to deactivate the old price, but don't fail the whole operation if it fails
+                        try:
+                            if self.stripe_price_id:
+                                stripe.Price.modify(self.stripe_price_id, active=False)
+                                logger.info(
+                                    f"Deactivated old Stripe price {self.stripe_price_id} for PurchasableProduct {self.id}"
+                                )
+                        except Exception:
+                            logger.exception(
+                                f"Failed to deactivate old Stripe price {self.stripe_price_id} for PurchasableProduct {self.id}"
+                            )
+
+                        # Switch to the new price id and persist it
+                        self.stripe_price_id = new_price.id
+                        if "stripe_price_id" not in changed_fields:
+                            changed_fields.append("stripe_price_id")
+
+                        logger.info(
+                            f"Created new Stripe price {self.stripe_price_id} for PurchasableProduct {self.id}"
+                        )
+                except Exception:
+                    logger.exception(
+                        f"Failed to create or switch Stripe price for PurchasableProduct {self.id}"
+                    )
+
+            # Persist any changed stripe ids without triggering further Stripe operations
+            if changed_fields:
+                super().save(update_fields=changed_fields)
+
+        except Exception as e:
+            logger.exception(
+                f"Failed to create/update Stripe product/price for PurchasableProduct {self.id}: {e}"
+            )
+
+    def delete(self, *args, **kwargs):
+        """Try to clean up Stripe resources when the product is deleted locally."""
+        stripe_api_key = getattr(
+            settings, "STRIPE_SECRET_KEY", os.getenv("STRIPE_SECRET_KEY")
+        )
+
+        if not stripe_api_key:
+            logger.debug(
+                "STRIPE_SECRET_KEY not set, skipping Stripe product/price cleanup"
+            )
+            return super().delete(*args, **kwargs)
+
+        stripe.api_key = stripe_api_key
+        # Attempt to deactivate price and delete product. Be tolerant of failures.
+        if self.stripe_price_id:
+            try:
+                stripe.Price.modify(self.stripe_price_id, active=False)
+                logger.info(
+                    f"Deactivated Stripe price {self.stripe_price_id} for PurchasableProduct {self.id}"
+                )
+            except Exception:
+                logger.exception(
+                    f"Failed to deactivate Stripe price {self.stripe_price_id} for PurchasableProduct {self.id}"
+                )
+
+        if self.stripe_product_id:
+            try:
+                stripe.Product.modify(self.stripe_product_id, active=False)
+                logger.info(
+                    f"Deactivated Stripe product {self.stripe_product_id} for PurchasableProduct {self.id}"
+                )
+            except Exception:
+                logger.exception(
+                    f"Failed to deactivate Stripe product {self.stripe_product_id} for PurchasableProduct {self.id}"
+                )
+
+        return super().delete(*args, **kwargs)