final class JuiceOrderViewController: UIViewController {
    ...
    private func presentChangeStockViewController() {
        guard let viewController = storyboard?
            .instantiateViewController(identifier: "ChangeStockViewController") as? ChangeStockViewController else { return }
        viewController.delegate = self
        viewController.modalPresentationStyle = .fullScreen
        present(viewController, animated: true)
    }
     ...
}

extension JuiceOrderViewController: StockDelegate {
    func getCurrentStock() -> [Int] {
        return Fruits.allCases.map { fruits in
            juiceMaker.fruitStore.bringQuantity(of: fruits) }
    }
    
    func addStock(quantities: [Int]) {
        for (index, fruit) in Fruits.allCases.enumerated() {
            juiceMaker.fruitStore.addStock(fruit: fruit, quantity: quantities[index])
        }
    }
}

protocol StockDelegate: AnyObject {
    func getCurrentStock() -> [Int]
    func addStock(quantities: [Int])
}

final class ChangeStockViewController: UIViewController {
    ...
    weak var delegate: StockDelegate?
    ... 
    private func initializeStockLabels() {
        guard let currentStock = delegate?.getCurrentStock() else { return }
        initialStock = currentStock
        for (index, label) in stockChangeLabels.enumerated() {
            label.text = "\(initialStock[index])"
        }
    }
    
    @IBAction private func hitDismissButton(_ sender: UIBarButtonItem) {
        delegate?.addStock(quantities: additionalStock)
        dismiss(animated: true)
    }
    ...
}

final class JuiceOrderViewController: UIViewController {
    ...
    private func presentChangeStockViewController() {
        guard let viewController = storyboard?
            .instantiateViewController(identifier: "ChangeStockViewController") as? ChangeStockViewController else { return }
        viewController.getCurrentHandler = self.getCurrentStock
        viewController.addStockHandler = self.addStock
        viewController.modalPresentationStyle = .fullScreen
        present(viewController, animated: true)
    }
    
    private func getCurrentStock() -> [Int] {
        return Fruits.allCases.map { fruits in
            juiceMaker.fruitStore.bringQuantity(of: fruits) }
    }

    private func addStock(_ quantities: [Int]) {
        for (index, fruit) in Fruits.allCases.enumerated() {
            juiceMaker.fruitStore.addStock(fruit: fruit, quantity: quantities[index])
        }
    }
    ...
}

final class ChangeStockViewController: UIViewController {
    ...
    var getCurrentHandler: (() -> [Int])?
    var addStockHandler: ((_ quantities:[Int]) -> Void)?
    ...    
    private func initializeStockLabels() {
        guard let currentStock = getCurrentHandler?() else { return }
        initialStock = currentStock
        for (index, label) in stockChangeLabels.enumerated() {
            label.text = "\(initialStock[index])"
        }
    }
    
    @IBAction private func hitDismissButton(_ sender: UIBarButtonItem) {
        addStockHandler?(additionalStock)
        dismiss(animated: true)
    }
    ...
}

final class JuiceOrderViewController: UIViewController {
    ...
    override func viewDidLoad() {
        super.viewDidLoad()
        NotificationCenter.default.addObserver(self, selector: #selector(addStock(_:)),
                                               name: Notification.Name("changeStock"),
                                               object: nil)
    }
        ...    
    @objc func addStock(_ notification: NSNotification) {
        guard let notifi = notification.userInfo?["additionalStock"] as? [Int] else { return }
        for (index, fruit) in Fruits.allCases.enumerated() {
        juiceMaker.fruitStore.addStock(fruit: fruit, quantity: notifi[index])
        }
    }
}

final class ChangeStockViewController: UIViewController {
		...    
    @IBAction private func hitDismissButton(_ sender: UIBarButtonItem) {
        NotificationCenter.default.post(name: Notification.Name("changeStock"),
                                        object: nil,
                                        userInfo: ["additionalStock": additionalStock])
        dismiss(animated: true)
    }
    ...
}

@IBAction private func hitStrawberryJuiceOrderButton(_ sender: UIButton) {
		placeAnOrder(for: .strawberryJuice)
}

@IBAction private func hitBananaJuiceOrderButton(_ sender: UIButton) {
		placeAnOrder(for: .bananaJuice)
}

...

private func searchJuice(by tag: Int) -> Juice? {
    switch tag {
    case 1:
        return .strawberryJuice
    case 2:
        return .bananaJuice
		...
    default:
        return nil
    }
}

@IBAction private func hitJuiceOrderButton(_ sender: UIButton) {
    guard let choosedJuice = searchJuice(by: sender.tag) else { return }
		placeAnOrder(for: choosedJuice)
}

private func searchJuice(by tag: Int) -> Juice? {
    switch tag {
    case 1:
        return .strawberryJuice
    case 2:
        return .bananaJuice
		...
    default:
        return nil
    }
}

@IBAction private func hitJuiceOrderButton(_ sender: UIButton) {
    guard let choosedJuice = searchJuice(by: sender.tag) else { return }
		placeAnOrder(for: choosedJuice)
}

private func searchJuice(by buttonTitle: String) -> Juice? {
    switch buttonTitle {
    case "딸기쥬스 주문":
        return .strawberryJuice
    case "바나나쥬스 주문":
        return .bananaJuice
    ...
    default:
        return nil
    }
}

private enum ButtonTitle {
    static let strawberryJuiceOrder = "딸기쥬스 주문"
    static let bananaJuiceOrder = "바나나쥬스 주문"
    ...
}
    
private func searchJuice(by buttonTitle: String) -> Juice? {
    switch buttonTitle {
    case ButtonTitle.strawberryJuiceOrder:
        return .strawberryJuice
    case ButtonTitle.bananaJuiceOrder:
        return .bananaJuice
		...
    default:
        return nil
    }
}

let initialStock = 10
var fruitStock: [Fruits: Int] = [
    .strawberry: initialStock, 
    .banana: initialStock,
    .pineapple: initialStock, 
    .mango: initialStock,
    .kiwi: initialStock
]	

static let initialStock = 10
var fruitStock: [Fruits: Int] = [
    .strawberry: initialStock, 
    .banana: initialStock,
    .pineapple: initialStock, 
    .mango: initialStock,
    .kiwi: initialStock
]	

private let initialStock = 10
private(set) lazy var fruitStock: [Fruits: Int] = [
    .strawberry: initialStock, 
    .banana: initialStock,
    .pineapple: initialStock, 
    .mango: initialStock,
    .kiwi: initialStock
]	

init(initialStock: Int = 10) {
    self.fruitStock = [.strawberry: initialStock,
                        .banana: initialStock,
                        .pineapple: initialStock,
                        .kiwi: initialStock,
                        .mango: initialStock]
    }

private func checkFruitStock(_ recipe: [Recipe]) -> Result<Bool, JuiceMakerError> {
    for fruit in recipe {
        guard let stock = fruitStore.fruitStock[fruit.name] else { return .failure(JuiceMakerError.notExistFruit) }
        guard stock >= fruit.quantity else { return .failure(JuiceMakerError.ingredientShortage) }
    }
    return .success(true)
}

private func checkFruitStock(_ recipe: [Recipe]) -> Result<Void, JuiceMakerError> {
    for fruit in recipe {
        guard let stock = fruitStore.fruitStock[fruit.name] else { return .failure(JuiceMakerError.notExistFruit) }
        guard stock >= fruit.quantity else { return .failure(JuiceMakerError.ingredientShortage) }
    }
    return .success(())
}

private func checkFruitStock(_ recipe: [(name: Fruits, quantity: Int)]) -> Result<Void, StockError> {}

typealias Recipe = (name: Fruits, quantity: Int)

private func checkFruitStock(_ recipe: [Recipe]) -> Result<Void, StockError> {}

func receiveRecipe() -> [Recipe] {
    switch self {
    case .strawberryJuice:
        return [(.strawberry, 16)]
    case .bananaJuice:
        return [(.banana, 2)]
    case .kiwiJuice:
        return [(.kiwi, 3)]
    case .pineappleJuice:
        return [(.pineapple, 2)]
    case .strawberryBananaJuice:
        return [(.strawberry, 10), (.banana, 1)]
    case .mangoJuice:
        return [(.mango, 3)]
    case .mangoKiwiJuice:
        return [(.mango, 2), (.kiwi, 1)]
    }
}

var recipe: [Recipe] {
    switch self {
    case .strawberryJuice:
        return [(.strawberry, 16)]
    case .bananaJuice:
        return [(.banana, 2)]
    case .kiwiJuice:
        return [(.kiwi, 3)]
    case .pineappleJuice:
        return [(.pineapple, 2)]
    case .strawberryBananaJuice:
        return [(.strawberry, 10), (.banana, 1)]
    case .mangoJuice:
        return [(.mango, 3)]
    case .mangoKiwiJuice:
        return [(.mango, 2), (.kiwi, 1)]
    }
}