payment gateways and plans billing and signup pages refactored

backend/igny8_core/business/billing/models.py

@@ -487,6 +487,7 @@ class Payment(AccountBaseModel):
     manual_reference = models.CharField(
         max_length=255,
         blank=True,
+        null=True,
         help_text="Bank transfer reference, wallet transaction ID, etc."
     )
     manual_notes = models.TextField(blank=True, help_text="Admin notes for manual payments")
@@ -526,9 +527,24 @@ class Payment(AccountBaseModel):
             models.Index(fields=['account', 'payment_method']),
             models.Index(fields=['invoice', 'status']),
         ]
+        constraints = [
+            # Ensure manual_reference is unique when not null/empty
+            # This prevents duplicate bank transfer references
+            models.UniqueConstraint(
+                fields=['manual_reference'],
+                name='unique_manual_reference_when_not_null',
+                condition=models.Q(manual_reference__isnull=False) & ~models.Q(manual_reference='')
+            ),
+        ]
     
     def __str__(self):
         return f"Payment {self.id} - {self.get_payment_method_display()} - {self.amount} {self.currency}"
+    
+    def save(self, *args, **kwargs):
+        """Normalize empty manual_reference to NULL for proper uniqueness handling"""
+        if self.manual_reference == '':
+            self.manual_reference = None
+        super().save(*args, **kwargs)
 
 
 class CreditPackage(models.Model):
@@ -854,3 +870,115 @@ class AIModelConfig(models.Model):
             model_type='image', 
             is_active=True
         ).order_by('quality_tier', 'model_name')
+
+
+class WebhookEvent(models.Model):
+    """
+    Store all incoming webhook events for audit and replay capability.
+    
+    This model provides:
+    - Audit trail of all webhook events
+    - Idempotency verification (via event_id)
+    - Ability to replay failed events
+    - Debugging and monitoring
+    """
+    PROVIDER_CHOICES = [
+        ('stripe', 'Stripe'),
+        ('paypal', 'PayPal'),
+    ]
+    
+    # Unique identifier from the payment provider
+    event_id = models.CharField(
+        max_length=255,
+        unique=True,
+        db_index=True,
+        help_text="Unique event ID from the payment provider"
+    )
+    
+    # Payment provider
+    provider = models.CharField(
+        max_length=20,
+        choices=PROVIDER_CHOICES,
+        db_index=True,
+        help_text="Payment provider (stripe or paypal)"
+    )
+    
+    # Event type (e.g., 'checkout.session.completed', 'PAYMENT.CAPTURE.COMPLETED')
+    event_type = models.CharField(
+        max_length=100,
+        db_index=True,
+        help_text="Event type from the provider"
+    )
+    
+    # Full payload for debugging and replay
+    payload = models.JSONField(
+        help_text="Full webhook payload"
+    )
+    
+    # Processing status
+    processed = models.BooleanField(
+        default=False,
+        db_index=True,
+        help_text="Whether this event has been successfully processed"
+    )
+    processed_at = models.DateTimeField(
+        null=True,
+        blank=True,
+        help_text="When the event was processed"
+    )
+    
+    # Error tracking
+    error_message = models.TextField(
+        blank=True,
+        help_text="Error message if processing failed"
+    )
+    retry_count = models.IntegerField(
+        default=0,
+        help_text="Number of processing attempts"
+    )
+    
+    # Timestamps
+    created_at = models.DateTimeField(auto_now_add=True)
+    
+    class Meta:
+        app_label = 'billing'
+        db_table = 'igny8_webhook_events'
+        verbose_name = 'Webhook Event'
+        verbose_name_plural = 'Webhook Events'
+        ordering = ['-created_at']
+        indexes = [
+            models.Index(fields=['provider', 'event_type']),
+            models.Index(fields=['processed', 'created_at']),
+            models.Index(fields=['provider', 'processed']),
+        ]
+    
+    def __str__(self):
+        return f"{self.provider}:{self.event_type} - {self.event_id[:20]}..."
+    
+    @classmethod
+    def record_event(cls, event_id: str, provider: str, event_type: str, payload: dict):
+        """
+        Record a webhook event. Returns (event, created) tuple.
+        If the event already exists, returns the existing event.
+        """
+        return cls.objects.get_or_create(
+            event_id=event_id,
+            defaults={
+                'provider': provider,
+                'event_type': event_type,
+                'payload': payload,
+            }
+        )
+    
+    def mark_processed(self):
+        """Mark the event as successfully processed"""
+        from django.utils import timezone
+        self.processed = True
+        self.processed_at = timezone.now()
+        self.save(update_fields=['processed', 'processed_at'])
+    
+    def mark_failed(self, error_message: str):
+        """Mark the event as failed with error message"""
+        self.error_message = error_message
+        self.retry_count += 1
+        self.save(update_fields=['error_message', 'retry_count'])