go-fish/internal/game/cards.go

package game

import "math/rand"

type Rank int

const (
	RankAce Rank = iota
	Rank2
	Rank3
	Rank4
	Rank5
	Rank6
	Rank7
	Rank8
	Rank9
	Rank10
	RankJack
	RankQueen
	RankKing
)

func (r Rank) String() string {
	switch r {
	case RankAce:
		return "A"
	case Rank2:
		return "2"
	case Rank3:
		return "3"
	case Rank4:
		return "4"
	case Rank5:
		return "5"
	case Rank6:
		return "6"
	case Rank7:
		return "7"
	case Rank8:
		return "8"
	case Rank9:
		return "9"
	case Rank10:
		return "10"
	case RankJack:
		return "J"
	case RankQueen:
		return "Q"
	case RankKing:
		return "K"
	}
	return "?"
}

type Suit int

const (
	SuitClubs Suit = iota
	SuitDiamonds
	SuitHearts
	SuitSpades
)

func (s Suit) String() string {
	switch s {
	case SuitClubs:
		return "♣"
	case SuitDiamonds:
		return "♦"
	case SuitHearts:
		return "♥"
	case SuitSpades:
		return "♠"
	}
	return "?"
}

type Card struct {
	Rank Rank
	Suit Suit
}

func NewDeck() []Card {
	var deck []Card
	for suit := SuitClubs; suit <= SuitSpades; suit++ {
		for rank := RankAce; rank <= RankKing; rank++ {
			deck = append(deck, Card{Rank: rank, Suit: suit})
		}
	}
	return deck
}

func Shuffle(deck []Card) []Card {
	result := make([]Card, len(deck))
	copy(result, deck)
	for i := len(result) - 1; i > 0; i-- {
		j := rand.Intn(i + 1)
		result[i], result[j] = result[j], result[i]
	}
	return result
}

var faceCards = map[Rank]bool{
	RankJack:  true,
	RankQueen: true,
	RankKing:  true,
}

func IsFaceCard(r Rank) bool {
	return faceCards[r]
}