NavigationStack_NavigationPath.swift

import SwiftUI

struct ContentView: View {
    
    @State var path = NavigationPath()
        
    var body: some View {
        NavigationStack(path: $path) {
            List {
                Section {
                    ForEach(Fruit.allCases) { fruit in
                        NavigationLink(fruit.name, value: fruit)
                    }
                } header: { Text("Fruits") }
                
                Section {
                    ForEach(Vegetable.allCases) { vegetable in
                        NavigationLink(vegetable.name, value: vegetable)
                    }
                } header: { Text("Vegetables") }
            }
            .navigationTitle("Food")
            .navigationDestination(for: Fruit.self) { fruit in
                FruitView(fruit: fruit){ nextFruit in
                    NavigationLink(value: nextFruit) {
                        Text("Next \(nextFruit.rawValue)")
                    }
                    .buttonStyle(.plain)
                }
                .toolbar {
                    ToolbarItem(placement: .navigationBarTrailing) {
                        Button {
                            nextRandom()
                        } label: {
                            Text("Next Random")
                                .foregroundColor(.black)
                        }

                    }
                }
            }
            .navigationDestination(for: Vegetable.self) { vegetable in
                VegetableView(vegetable: vegetable){ nextVegetable in
                    NavigationLink(value: nextVegetable) {
                        Text("Next \(nextVegetable.rawValue)")
                    }
                    .buttonStyle(.plain)
                }
                .toolbar {
                    ToolbarItem(placement: .navigationBarTrailing) {
                        Button {
                            nextRandom()
                        } label: {
                            Text("Next Random")
                                .foregroundColor(.black)
                        }

                    }
                }
            }
        }
    }

    func nextRandom() {
        let value: any Hashable = Bool.random() ? Fruit.random : Vegetable.random
        path.append(value)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}


enum Fruit: String, Hashable, CaseIterable {
    case banana = "🍌"
    case orange = "🍊"
    case peach = "🍑"
    case apple = "🍎"
    
    static var random: Self {
        Self.allCases.randomElement()!
    }
    
    var color: Color {
        switch self {
        case .banana:
            return .yellow
        case .orange:
            return .orange
        case .peach:
            return .pink
        case .apple:
            return .red
        }
    }
    
    var name: String {
        switch self {
        case .banana:
            return "Banana"
        case .orange:
            return "Orange"
        case .peach:
            return "Peach"
        case .apple:
            return "Apple"
        }
    }
}
extension Fruit: Identifiable {
    var id: String { self.rawValue }
}

enum Vegetable: String, Hashable, CaseIterable {
    case tomato = "🍅"
    case avocado = "🥑"
    case potato = "🥔"
    case broccoli = "🥦"
    
    static var random: Self {
        Self.allCases.randomElement()!
    }
    
    var color: Color {
        switch self {
        case .tomato:
            return .red
        case .avocado:
            return .green
        case .potato:
            return .yellow
        case .broccoli:
            return .green
        }
    }
    
    var name: String {
        switch self {
        case .tomato:
            return "Tomato"
        case .avocado:
            return "Avocado"
        case .potato:
            return "Potato"
        case .broccoli:
            return "Broccoli"
        }
    }
}
extension Vegetable: Identifiable {
    var id: String { self.rawValue }
}

struct FruitView<Link: View>: View {
    let fruit: Fruit
    var nextLink:  ((Fruit) -> Link)? = nil
    
    var body: some View {
        ZStack {
            fruit.color.opacity(0.2).ignoresSafeArea(.all)
            VStack {
                Text(fruit.rawValue)
                    .font(.system(size: 100))
                    .padding()
                nextLink?(Fruit.random)
            }
        }
        .navigationTitle("\(fruit.name)")
    }
}

struct VegetableView<Link: View>: View {
    let vegetable: Vegetable
    var nextLink:  ((Vegetable) -> Link)? = nil
    
    var body: some View {
        ZStack {
            vegetable.color.opacity(0.2).ignoresSafeArea(.all)
            VStack {
                Text(vegetable.rawValue)
                    .font(.system(size: 100))
                    .padding()
                nextLink?(Vegetable.random)
            }
        }
        .navigationTitle("\(vegetable.name)")
    }
}