How can I offer gifts based on product metafields in the cart?

[rohit-world]

Hey I wanted to implement a feature where I added meta-fields in product section called PV integer value in every product.  now In the cart I wanted to give a gift to the customers if he added some products and reached the certain PV value,  please suggest me any or other things because current I can set the gift basis on certain amount , but I wanted to change it to PV