//
//  CheckoutView.swift
//  CupcakeCorner
//
//  Created by Nick Lockwood on 28/06/2020.
//  Copyright © 2020 Nick Lockwood. All rights reserved.
//

import SwiftUI

struct CheckoutView: View {
  @ObservedObject var order = Order()

  @State private var confirmationMessage = ""
  @State private var showingConfirmation = false

  var body: some View {
    GeometryReader { geo in
      ScrollView {
        VStack {
          Image("cupcakes")
            .resizable()
            .scaledToFit()
            .frame(width: geo.size.width)

          Text("Your total is $\(self.order.data.cost, specifier: "%.2f")")
            .font(.title)

          Button("Place order", action: self.placeOrder)
            .padding()
        }
      }
    }
    .navigationBarTitle("Check out", displayMode: .inline)
    .alert(isPresented: $showingConfirmation) {
      Alert(title: Text("Thank you!"),
            message: Text(confirmationMessage),
            dismissButton: .default(Text("OK")))
    }
  }

  func placeOrder() {
    guard let encoded = try? JSONEncoder().encode(order) else {
      print("Failed to encode order")
      return
    }

    let url = URL(string: "https://reqres.in/api/cupcakes")!
    var request = URLRequest(url: url)
    request.setValue("application/json", forHTTPHeaderField: "Content-Type")
    request.httpMethod = "POST"
    request.httpBody = encoded

    URLSession.shared.dataTask(with: request) { data, _, error in
      guard let data = data else {
        self.confirmationMessage = "No data in response: \(error?.localizedDescription ?? "Unknown error")."
        self.showingConfirmation = true
        return
      }
      if let decodedOrder = try? JSONDecoder().decode(Order.self, from: data) {
        self.confirmationMessage = "Your order for \(decodedOrder.data.quantity)x \(Order.types[decodedOrder.data.type].lowercased()) cupcakes is on its way!"
      } else {
        self.confirmationMessage = "Invalid response from server"
      }
      self.showingConfirmation = true
    }.resume()
  }
}

struct CheckoutView_Previews: PreviewProvider {
  static var previews: some View {
    CheckoutView(order: Order())
  }
}