NumberGuessingGameView.swift

import SwiftUI

struct NumberGuessingGameView: View {

  private var gameViewModel: NumberGuessingGame

  @State private var guessLabel = "Guess the number!"
  @State private var guess = ""
  @State private var showAlert = false

  public init(gameViewModel: NumberGuessingGame) {
    self.gameViewModel = gameViewModel
  }

  var body: some View {
    VStack {
      Text(guessLabel)
      TextField(
        "Type a number",
        text: $guess
      )
      .keyboardType(.numberPad)
      .textFieldStyle(RoundedBorderTextFieldStyle())
      .multilineTextAlignment(.center)

      Button(
        "Enter guess",
        action: {
          if let userGuess = Int(self.guess) {
            self.gameViewModel.makeGuess(withNumber: userGuess)
            self.guessLabel =
              self.gameViewModel.status == .playing ? "Try again!" : "Guess the Number!"
            self.showAlert = self.gameViewModel.status == .won || self.gameViewModel.status == .lost
          }
          self.guess = ""
        }
      )
      .alert(isPresented: $showAlert) {
        let title = gameViewModel.status == .won ? "You won! 🥳" : "You lost! 😢"
        return Alert(
          title: Text(title),
          message: nil,
          dismissButton: .default(Text("Start new game"), action: {
            self.gameViewModel.reset()
          })
        )
      }
    }.padding()
  }
}