Instructions

What’s included in this repository?

This repository contains a Spring Boot application with the following structure:

• The domain includes three entities: Brand, Vehicle, and Sale.
  • A Brand can have multiple Vehicles.
  • A Sale is associated with a Vehicle, a Brand, and a date.
• The application exposes a REST API that allows basic CRUD operations.
• Each entity is handled through its own Controller, Service, and Repository.
• The application uses Spring Data JPA to interact with the database.
• It uses an H2 in-memory database, preloaded with sample data, and is configured to run on port 8080.

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What do you need to implement?

1. Implement Spring Security:

   • All GET endpoints must remain public (no authentication required).
   • All POST, PUT, and DELETE endpoints must require authentication and authorization.

2. Add the following endpoints to the SalesController:

   • GET /api/sales/brands/{brandId} → Return all sales for a given brand.
   • GET /api/sales/vehicles/{vehicleId} → Return all sales for a given vehicle.
   • Modify the existing GET /api/sales endpoint and add pagination to it.
     • Each response must return 10 items per page.
     • The page number must be accepted as an optional query parameter.
     • If the page number is not provided, the API should return the first page by default.

3. Implement a new endpoint in SalesController:

   • GET /api/sales/vehicles/bestSelling → Return the top 5 best-selling vehicles.
   • Allow optional filtering by start date and end date.
   • You must retrieve all sales from the database (as currently implemented).
     • Do not use SQL-level sorting, Collections.sort(), or any built-in sort utilities.
     • Implement your own sorting logic using Java code, considering performance (imagine millions of records).
     • You may create additional models or helper classes as needed.

4. Create a custom filter or interceptor using Spring:

   • It must log all incoming API requests and outgoing responses to a file.
   • The log must include:
     • Request date and time
     • HTTP method
     • Request URL
     • Response status code
     • Processing time (in milliseconds)

5. Implement a caching system for the GET endpoints of Brand

   • Check if the data exists in the cache and has not expired.
   • If it does not exist or has expired, call the supplier.
   • Update the cache with the new value.
   • Handle concurrency properly.

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Additional Information

• You must use Java 21.
• Do not use any external libraries — all code must be implemented by you.
• If there’s something you’re not sure how to do, don’t worry — just give it your best effort.
• We will carefully review your code and provide feedback as soon as possible.