import Foundation

enum Suit {
    case hearts
    case spades
    case diamonds
    case clubs
}

extension Suit {
    var shape: String {
        switch self {
        case .hearts: return "♥️"
        case .spades: return "♠️"
        case .diamonds: return "♦️"
        case .clubs: return "♣️"
        }
    }
}

struct Card {
    let suit: Suit
    let rank: Int
}

extension Card: CustomStringConvertible {

    var description: String {
        return
        """
        \(rank) of \(suit.shape)
        """
    }
}

struct Deck {
    var cards: [Card] = []

    init() {
        cards.append(contentsOf: cards(for: .hearts))
        cards.append(contentsOf: cards(for: .spades))
        cards.append(contentsOf: cards(for: .diamonds))
        cards.append(contentsOf: cards(for: .clubs))
    }

    private func cards(for suit: Suit) -> [Card] {
        return Array(1...13).map{ Card(suit: suit, rank: $0) }
    }

    func draw() -> Card? {
        let rand = Int(arc4random_uniform(UInt32(cards.count-1)))
        return cards[rand]
    }
}

// Tests
let deck = Deck()

if deck.cards.count == 52 {
    print("Pass: 52 cards in deck")
}

if let card = deck.draw() {
    print("Pass: Draw \(card)")
}