# Celery Tasks

All tasks are defined in `subscriptions.tasks` and are designed to run via Celery Beat (periodic scheduling).

## Setup

Run the management command to register periodic tasks in Django Celery Beat:

```bash
python manage.py setup_periodic_tasks
```

Start the Celery worker and beat scheduler:

```bash
# Worker
celery -A config worker -l info

# Beat (periodic scheduler)
celery -A config beat -l info --scheduler django_celery_beat.schedulers:DatabaseScheduler
```

## Task Reference

### `process_due_subscriptions`

**Schedule:** Every hour  
**Retries:** 3 (60s delay)

Processes all subscriptions due for billing. Creates a charge via Midtrans for each due subscription. Skips native Midtrans subscriptions (they handle billing internally). Expires subscriptions that have reached `max_cycles`.

### `process_expired_subscriptions`

**Schedule:** Every 6 hours

Finds subscriptions marked as `cancel_at_period_end=True` whose period has ended, and cancels them.

### `process_past_due_expiration`

**Schedule:** Every 6 hours

Expires subscriptions that have been `past_due` beyond the grace period (`GRACE_PERIOD_DAYS`).

### `retry_failed_payments`

**Schedule:** Every 3 hours

Retries failed payments for past-due subscriptions. Respects:
- `AUTO_RETRY_FAILED_PAYMENTS` — Enable/disable
- `MAX_RETRY_ATTEMPTS` — Maximum retries (default: 3)
- `RETRY_INTERVAL_DAYS` — Days between retries (default: 1)

### `mark_overdue_invoices`

**Schedule:** Daily at midnight

Marks invoices past their `due_date` as overdue and creates notification log entries.

### `send_expiry_reminders`

**Schedule:** Daily at 9:00 AM

Sends reminder notifications for subscriptions expiring within `EXPIRY_REMINDER_DAYS` (default: 7, 3, and 1 days). Prevents duplicate reminders for the same day.

### `sync_midtrans_subscriptions`

**Schedule:** Every 6 hours

Syncs subscription status from Midtrans API for all subscriptions with a `midtrans_subscription_id`. Ensures local state matches Midtrans.

### `process_wallet_billing`

**Schedule:** Every hour  
**Retries:** 3 (60s delay)

Processes billing for wallet-paid subscriptions. Debits the user's wallet for due subscriptions. If insufficient balance, marks the subscription as `past_due`.

### `check_pending_payment_status`

**Schedule:** On-demand (not periodic)

Checks the status of a specific pending payment from Midtrans. Useful when webhook notifications are missed.

```python
from subscriptions.tasks import check_pending_payment_status

check_pending_payment_status.delay(str(payment.id))
```

### `send_pending_email_notifications`

**Schedule:** Every 5 minutes

Processes queued email notifications and sends them via Django's `send_mail()`. Batches up to 100 notifications per run.

## Task Summary Table

| Task | Schedule | Description |
|------|----------|-------------|
| `process_due_subscriptions` | Every hour | Bill due subscriptions |
| `process_expired_subscriptions` | Every 6 hours | Cancel subscriptions at period end |
| `process_past_due_expiration` | Every 6 hours | Expire past-due beyond grace period |
| `retry_failed_payments` | Every 3 hours | Retry failed charges |
| `mark_overdue_invoices` | Daily midnight | Mark overdue invoices |
| `send_expiry_reminders` | Daily 9 AM | Send expiry reminders |
| `sync_midtrans_subscriptions` | Every 6 hours | Sync with Midtrans API |
| `process_wallet_billing` | Every hour | Bill wallet subscriptions |
| `send_pending_email_notifications` | Every 5 min | Send queued emails |

## Customizing Schedules

After `setup_periodic_tasks`, you can modify schedules in the Django admin under "Periodic Tasks" (Celery section).

You can also override the setup command or add custom tasks by subclassing the management command.