Online store with barcode scanner

It is necessary to develop an online store with the functionality of collecting an order using a bar code scanner. The order gets into the admin, the administrator accepts this order and begins its collection, scanning the bar codes, while summing up the total weight of the order (weight goods, vegetables / fruits) and the total amount of the order. Based on the total weight of the order, the cost of sending by mail to the Russian tarifficator is calculated. I have a more detailed TK, I will send it to interested candidates.