How to implement functionality considering the principles of clean architecture, where the application performs network requests and processes certain operations?

For implementing network requests and processing operations in an application following clean architecture principles, code should be divided into layers:

• Domain (Business Logic Layer) — contains business logic and repository interfaces.
• Data Layer — implements repository interfaces, performs network requests, database operations, etc.
• Presentation Layer — UI and user interaction.

For example, a network request is implemented in the Data layer through a repository, which is injected into the domain layer. The domain layer describes a use case that calls repository methods and processes data.

Example of a repository interface in the domain layer:

interface UserRepository {
    suspend fun fetchUser(userId: String): User
}

Implementation in the Data layer:

class UserRepositoryImpl(private val apiService: ApiService) : UserRepository {
    override suspend fun fetchUser(userId: String): User {
        return apiService.getUser(userId)
    }
}

Use case in the domain layer:

class GetUserUseCase(private val userRepository: UserRepository) {
    suspend operator fun invoke(userId: String): User {
        return userRepository.fetchUser(userId)
    }
}

Thus, the presentation layer calls the use case, which interacts with the repository, and the repository performs network operations. This ensures loose coupling and ease of testing.