Presenter.swift

protocol Presenter {
    /// Present the given content to the user.
    func present(title: String, description: String)
}

class ContentHandler {
    /// The presenter used to present content.
    private let presenter: Presenter
    
    init(presenter: Presenter) {
        self.presenter = presenter
    }
    
    /// Handles the input and present the corresponding content to the user.
    func handleInput(_ input: Int) {
        let title: String
        let description: String
        
        switch input {
        case Int.min...0:
            title = "Negative"
            description = "Less than zero"
        case 0...10:
            title = "Positive"
            description = "Great input"
        default:
            title = "Too high"
            description = "...Way too high"
        }
        presenter.present(title: title, description: description)
    }
}