Generate item barcode via server script

ERPNext Stock/Inventory
1

I am not yet familiar with server scripts syntax. I tried to write a script that creates a barcode for a new item at insert and i failed. here is what I tried:

def before_insert(doc, method):
try:

    if not doc.barcodes:
        doc.barcodes = []

    # Get the parent item group to help in generating barcodes
    parent_item_group = doc.get("parent_item_group")

   
    last_barcode = get_last_barcode(parent_item_group) if parent_item_group else None

    if last_barcode:
        try:
            # Increment the last barcode by 1 for sequential barcodes
            new_barcode_numeric = int(last_barcode) + 1
            new_barcode = str(new_barcode_numeric)
        except ValueError:
    
            new_barcode = generate_unique_barcode()
    else:
    
        new_barcode = generate_unique_barcode()

  
    doc.append("barcodes", {"barcode": new_barcode})

  
    barcode_doc = {
        "doctype": "Item Barcode",
        "item": doc.name,  # Link to the created Item
        "barcode": new_barcode
    }
    try:
        frappe.get_doc(barcode_doc).insert()
    except Exception as e:
        raise Exception(f"Error while creating Item Barcode: {str(e)}")
except Exception as e:
    raise Exception(f"Error in before_insert: {str(e)}")

I want to optimize this script to successfully automatically create a barcode entry that is a random 11 digits number for every item i create, whether it is a variant or not. How can I do that?