pokercore/examples/montecarlo/main.go

package main

import (
	"fmt"
	"time"

	"git.eeqj.de/sneak/pokercore"
	"github.com/rcrowley/go-metrics"
	"github.com/schollz/progressbar/v3"
)

var gameCount = 50_000
var playerCount = 2

type Player struct {
	Hand       pokercore.Cards
	ScoredHand *pokercore.PokerHand
	Position   int
}

type Game struct {
	Deck      *pokercore.Deck
	Players   []*Player
	Community pokercore.Cards
	Street    int
}

func NewGame() *Game {
	g := &Game{}
	g.Street = 0
	g.Deck = pokercore.NewDeck()
	g.Deck.ShuffleRandomly()
	return g
}

func (g *Game) StreetAsString() string {
	switch g.Street {
	case 0:
		return "pre-flop"
	case 1:
		return "flop"
	case 2:
		return "turn"
	case 3:
		return "river"
	}
	return "unknown"
}

func (g *Game) DealPlayersIn() {
	for i := 0; i < playerCount; i++ {
		p := Player{Hand: g.Deck.Deal(2), Position: i + 1}
		g.Players = append(g.Players, &p)
	}
}

func (g *Game) DealFlop() {
	g.Community = g.Deck.Deal(3)
	g.Street = 1
}

func (g *Game) DealTurn() {
	g.Community = append(g.Community, g.Deck.Deal(1)...)
	g.Street = 2
}

func (g *Game) DealRiver() {
	g.Community = append(g.Community, g.Deck.Deal(1)...)
	g.Street = 3
}

func (g *Game) ShowWinner() int {
	var winner *Player
	var winningHand *pokercore.PokerHand
	for _, p := range g.Players {
		if p != nil {
			ac := append(p.Hand, g.Community...)
			ph, err := ac.PokerHand()
			if err != nil {
				panic(err)
			}
			if winner == nil {
				winner = p
				winningHand = ph
			} else {
				if ph.Score > winningHand.Score {
					winner = p
					winningHand = ph
				}
			}
		}
	}
	return winner.Position
}

func main() {
	oneWins := 0
	twoWins := 0

	registry := metrics.NewRegistry()
	timer := metrics.NewTimer()
	registry.Register("pokerGame", timer)

	bar := progressbar.NewOptions(gameCount,
		progressbar.OptionSetDescription("Gambling..."),
		progressbar.OptionShowCount(),
		progressbar.OptionShowIts(),
		progressbar.OptionSetPredictTime(true),
		progressbar.OptionClearOnFinish(),
		progressbar.OptionThrottle(100*time.Millisecond), // Update every 100ms
	)

	for i := 0; i < gameCount; i++ {
		start := time.Now()
		w := runFlip()
		duration := time.Since(start)
		timer.Update(duration)
		bar.Add(1)
		if w == 1 {
			oneWins++
		} else {
			twoWins++
		}
	}

	fmt.Printf("%d games played\n", gameCount)
	fmt.Printf("Min: %d ns\n", timer.Min())
	fmt.Printf("Max: %d ns\n", timer.Max())
	fmt.Printf("Mean: %0.2f ns\n", timer.Mean())
	fmt.Printf("StdDev: %0.2f ns\n", timer.StdDev())
	fmt.Printf("Percentiles: 50%%: %0.2f ns, 75%%: %0.2f ns, 95%%: %0.2f ns, 99%%: %0.2f ns\n",
		timer.Percentile(0.50),
		timer.Percentile(0.75),
		timer.Percentile(0.95),
		timer.Percentile(0.99))
	oneWinPercentage := float64(oneWins) / float64(gameCount) * 100
	twoWinPercentage := float64(twoWins) / float64(gameCount) * 100
	fmt.Printf("Player 1 won: %d (%0.2f%%)\n", oneWins, oneWinPercentage)
	fmt.Printf("Player 2 won: %d (%0.2f%%)\n", twoWins, twoWinPercentage)
}

func runFlip() int {
	g := NewGame()
	g.DealPlayersIn()
	g.DealFlop()
	g.DealTurn()
	g.DealRiver()
	winnerPosition := g.ShowWinner()
	return winnerPosition
}