Cabify Mobile Challenge

Besides providing exceptional transportation services, Cabify also runs a physical store which sells Products.

Our list of products looks like this:

Code         | Name                |  Price
-------------------------------------------------
VOUCHER      | Cabify Voucher      |   5.00€
TSHIRT       | Cabify T-Shirt      |  20.00€
MUG          | Cabify Coffee Mug   |   7.50€

Various departments have insisted on the following discounts:

• The marketing department believes in 2-for-1 promotions (buy two of the same product, get one free), and would like to have a 2-for-1 special on VOUCHER items.

• The CFO insists that the best way to increase sales is with discounts on bulk purchases (buying x or more of a product, the price of that product is reduced), and demands that if you buy 3 or more TSHIRT items, the price per unit should be 19.00€.

Cabify's checkout process allows for items to be scanned in any order, and should return the total amount to be paid.

Examples:

Items: VOUCHER, TSHIRT, MUG
Total: 32.50€

Items: VOUCHER, TSHIRT, VOUCHER
Total: 25.00€

Items: TSHIRT, TSHIRT, TSHIRT, VOUCHER, TSHIRT
Total: 81.00€

Items: VOUCHER, TSHIRT, VOUCHER, VOUCHER, MUG, TSHIRT, TSHIRT
Total: 74.50€

To do

• Implement an app where a user can pick products from a list and checkout them to get the resulting price. No need to implement any real payment system, but we do need a nice user experience where our customers can understand what items are they purchasing, the price and the discount we are applying.
• You should fetch the list of products from here.

Considerations

• Be aware that the discounts are going to change frequently. So the code should support that.
• There is no need for a user login screen.
• Be written as production-ready code. We would like you to build it in the same way as if you were going to publish to the store.
• Consider explaning the solution and why certain things are included and others are left out.
• Be written either in Swift or Kotlin, preferably in the latest stable version of the language.
• If possible, use the latest stable version (no Betas) of Xcode or Android Studio.