import SwiftUI
import Combine

class Settings: ObservableObject {
    @Published var hasAgreedToTermsAndConditions: Bool = false
    @Published var hasAgreedToPrivacyPolicy: Bool = false

    @Published var isActive = false
    @Published var isNotActive = true

    private var cancellable: AnyCancellable? = nil

    init() {
        self.cancellable = Publishers.CombineLatest($hasAgreedToPrivacyPolicy, $hasAgreedToTermsAndConditions).map{
            return $0.0 && $0.1
        }.sink{
            self.isActive = $0
            self.isNotActive = !$0
        }
    }
}

struct WelcomeSceneView: View {
    @ObservedObject var settings = Settings()

    var body: some View {
        NavigationView {
            VStack {
                Image(uiImage: welcomeLogo)

                Spacer()

                Text("Welcome friend!".uppercased())
                //.font(.system(size: 55))

                Toggle(isOn: $settings.hasAgreedToTermsAndConditions) {
                    Text("I agree to the Terms and Conditions")
                }.toggleStyle(DefaultToggleStyle())

                Toggle(isOn: $settings.hasAgreedToPrivacyPolicy) {
                    Text("I agree to the Privacy Policy")
                }.toggleStyle(DefaultToggleStyle())


                // This does not compile 'Binding<Bool> is not convertible to Bool', but I cannot figure out how to create a compupted property binding using those 2 states...
                Text("is active: (settings.isActive.description)")
                NavigationLink("Can proceed", destination: SignInScene(), isActive: $settings.isActive)
                .hidden()
                NavigationLink("Can not proceed", destination: PleaseConfirmView(), isActive: $settings.isNotActive)
                .hidden()
            }.padding(30)
        }
    }

    let welcomeLogo = UIImage(systemName: "headphones")!
}

struct SignInScene: View {
    var body: some View {
        Text("Some sign in scene")
    }
}

struct PleaseConfirmView: View {
    var body: some View {
        Text("Please confirm")
    }
}