shopify eshop json api from metals-api.com

I have developed a shopify based bullion eshop (gold-silver coins and bars) already filled with 100-150 [login to view URL] project i am looking to develop is a custom app to take api from "[login to view URL]" and automatically bulk change the 100-150 products prices every hour/ 24 api calls per day. There will be α equation that will work like that: (api price) x (weight of product) + (% premium) 1)api price -the spot price of the metal of the product:gold,silver,palladium,platinum.Metals-api gives the prices per troy ounce so it must divided with 31.1034768 to take the price per gram. The price will be in EUR currency. 2)weight - is stable and unchangeable for every product and get it from the weight field of shopify product page 3)% premium - it will be a number (x) at the barcode field of shopify product page that it will used to add (x)% on the price like if the number is 8 then it comes x1.08 Products will have 2 letters at the start of SKU code: AU for gold, AG for silver,PT for platinum and PD for palladium to determine their metal. There must be a script that will use these fields to generate the price of every product and refresh their prices at shopify. The same custom app will use the same api to display the 4 metals prices and the day percent change in a head flexible [login to view URL] display in an inner page historical price charts of the 4 metals giving my clients the ability to choose the timeframe they want to see.