feat(invoice): enhance invoice update validation and payload construction

backend/api/v1/modules/a76/invoices/services.py

@@ -201,11 +201,40 @@ class InvoiceService:
         invoice_data: schemas.InvoiceHeaderUpdate,
         company_id: int,
     ) -> Optional[models.InvoiceHeader]:
-        # ... (El resto de tu código update se queda igual) ...
-        # (Te recomiendo implementar clean_dict aquí también si tienes problemas al editar)
+        """Update an existing invoice with validation"""
+        
+        # Validaciones con ErrorCollector
+        errors = ErrorCollector()
+        
+        # Obtener la factura existente
         invoice = InvoiceService.get_by_id(db, invoice_id, tenant_id, company_id)
         if not invoice:
             return None
+        
+        # Si se cambió el número de factura, validar que no exista otra con ese número
+        if invoice_data.invoice_number and invoice_data.invoice_number != invoice.invoice_number:
+            # Verificar que no exista otra factura con el nuevo número
+            existing_invoice = (
+                db.query(models.InvoiceHeader.id)
+                .filter(
+                    models.InvoiceHeader.invoice_number == invoice_data.invoice_number,
+                    models.InvoiceHeader.tenant_id == tenant_id,
+                    models.InvoiceHeader.company_id == company_id,
+                    models.InvoiceHeader.id != invoice_id,  # Excluir la factura actual
+                )
+                .first()
+            )
+            
+            if existing_invoice:
+                errors.add_duplicate_error(
+                    "invoice_number",
+                    invoice_data.invoice_number,
+                    f"Ya existe otra factura con el número '{invoice_data.invoice_number}'",
+                )
+        validate_update(invoice_data, invoice, errors)
+        
+        # Si hay errores, lanzar excepción ANTES de actualizar
+        errors.raise_if_errors("Error al actualizar la factura")
 
         # Update main invoice header fields
         update_dict = invoice_data.model_dump(