import SwiftUI

extension Identifiable where Self: Hashable {
    typealias ID = Self
    var id: Self { self }
}

struct SecondView: View {
    let text: String
    
    init(text: String) {
        self.text = text
        print("SecondView init")
    }
    
    var body: some View {
        VStack {
            Text(text)
        }
        .onAppear {
            print("SecondView onAppear")
        }
        .onDisappear {
            print("SecondView Disappear")
        }
    }
}

struct ThirdView: View {
    var body: some View {
        Text("ThirdView")
    }
}

struct SampleModalPushView: View {
    
    enum Presentation: View, Hashable, Identifiable {
        case second(text: String)
        case third
        var body: some View {
            switch self {
            case .second(let text): return AnyView(SecondView(text: text))
            case .third: return AnyView(ThirdView())
            }
        }
    }

    @State var presentation: Presentation?
    @State var presentationNav: (Bool, Presentation?) = (false, nil)
    
    var body: some View {
        NavigationView {
            ZStack {
                VStack(spacing: 20) {
                    Button(action: {
                        presentation = .second(text: "aaa")
                    }) {
                        Text("モーダル遷移")
                    }
                    
                    Button(action: {
                        presentationNav = (true, .second(text: "test"))
                    }) {
                        Text("プッシュ遷移")
                    }
                }
                
                NavigationLink(
                    destination: presentationNav.1,
                    isActive: $presentationNav.0,
                    label: EmptyView.init
                )
            }
        }
        .sheet(item: $presentation) { $0.body }
    }
}

struct SampleModalPushView_Previews: PreviewProvider {
    static var previews: some View {
        SampleModalPushView()
    }
}