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, just a fake feedback about the payment has been completed.
• The discounts can change in the future, depending on the year season we apply different ones.
• There is no need for a user login screen.
• We would like to show users what discounts have been applied in their purchase.
• You should get the list of products from here.

Bonus

• The app should work also offline, and all that this implies.

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Tech-stack

Min API level is set to 21, so the presented approach is suitable for over 85% of devices running Android. This project takes advantage of latest popular libraries and tools of the Android ecosystem

• Tech-stack
  • Kotlin + Coroutines - perform background operations
  • Koin - dependency injection
  • Retrofit - networking
  • Jetpack
    • Navigation - deal with whole in-app navigation
    • LiveData - lets the components in your app, usually the UI, observe LiveData objects for changes.
    • Lifecycle - perform action when lifecycle state changes
    • ViewModel - store and manage UI-related data in a lifecycle conscious way
    • Room - create a cache of your app's data on a device that's running your app
  • Glide - image loading library
• Architecture
  • Clean Architecture
  • MVVM + Data Binding (presentation layer)
  • Android Architecture components (ViewModel, LiveData, Navigation)
• Tests
  • Unit Tests (JUnit)
  • Mockk
  • Espresso (UI)