path: root/internal/casino/craps_projection.go

package casino

import (
	"fmt"
	"sort"
	"strings"
)

// crapsReturn is the pure payout math shared by settlement and by the
// player-facing "what could win on the next roll" projection, so the two can
// never disagree. It mirrors the money path of crapsTable.pay exactly.
func crapsReturn(b *crapsBet, profit, den, oddsProfit int, refundOdds bool) int {
	payout := 0
	if profit >= 0 {
		payout = b.stake.Total + b.stake.Total/den*profit
		if b.kind == "buy" || b.kind == "lay" {
			base := payout - b.stake.Total
			if b.kind == "buy" {
				base = b.stake.Total
			}
			// Removals (zero profit) return the full stake without commission.
			if profit > 0 {
				payout -= (base + 19) / 20
			}
		}
	}
	if b.odds.Total > 0 {
		if refundOdds {
			payout += b.odds.Total
		} else if oddsProfit >= 0 {
			x, y := crapsTrueOdds(b.number)
			if strings.HasPrefix(b.kind, "dont") {
				x, y = y, x
			}
			payout += b.odds.Total + b.odds.Total/y*x
		}
	}
	return payout
}

// crapsNet returns settlement profit: returns (stake included) less commit.
func crapsNet(b *crapsBet, profit, den, oddsProfit int, refundOdds bool) int {
	return crapsReturn(b, profit, den, oddsProfit, refundOdds) - (b.stake.Total + b.odds.Total)
}

// crapsRefundOdds mirrors come bets' come-out refundOdds policy.
func crapsRefundOdds(b *crapsBet, point int) bool { return point == 0 && b.kind == "come" }

// crapsRollView is one possible dice pair: its total, the pair shown, and the
// player's combined settlement profit if it rolled next.
type CrapsRollView struct {
	Total int
	Rolls string
	Net   int
}

// projectionFor evaluates one player's live bets as if the listed pair rolled
// with the current table point, via the same rules engine used for settlement.
func (t *crapsTable) projectionFor(p *crapsPlayer) []CrapsRollView {
	var rows []CrapsRollView
	for total := 2; total <= 12; total++ {
		for a := 1; a <= 6; a++ {
			b := total - a
			if b < 1 || b > 6 || a > b {
				continue
			}
			net := 0
			for _, bet := range p.bets {
				done, x, y := crapsOutcome(bet.kind, bet.number, a, b, t.point, t.Config.Craps.Field12)
				if !done {
					// An unresolved contract keeps its stake; only bonuses
					// can complete within a single non-settling roll.
					if bet.kind == "fire" {
						x = crapsFireProfit(len(t.made))
					} else if bet.kind == "small" || bet.kind == "tall" || bet.kind == "all" {
						lo, hi := 2, 12
						if bet.kind == "small" {
							hi = 6
						}
						if bet.kind == "tall" {
							lo = 8
						}
						if crapsBonusComplete(lo, hi, t.seen, a+b) {
							x = 34
							if bet.kind == "all" {
								x = 175
							}
						} else {
							continue
						}
					} else {
						continue
					}
				}
				net += crapsNet(bet, x, y, x, crapsRefundOdds(bet, t.point))
			}
			rows = append(rows, CrapsRollView{total, fmt.Sprintf("%d+%d", a, b), net})
		}
	}
	return rows
}

func crapsFireProfit(made int) int {
	switch made {
	case 4:
		return 24
	case 5:
		return 249
	case 6:
		return 999
	}
	return 0
}

func crapsBonusComplete(lo, hi int, seen map[int]bool, next int) bool {
	for n := lo; n <= hi; n++ {
		if n != 7 && !seen[n] && n != next {
			return false
		}
	}
	return true
}

// crapsRollLabel names the roll result a bet cares about: hardways and hop
// bets distinguish their exact pair ("4+4"); every other bet reads by total.
func crapsRollLabel(bet *crapsBet, a, b int) string {
	s := a + b
	switch bet.kind {
	case "hard":
		if a == b {
			return fmt.Sprintf("%d+%d", a, b)
		}
		if s == 7 {
			return "7"
		}
		return fmt.Sprintf("easy %d", s)
	case "hop":
		if bet.number == a*10+b || bet.number == b*10+a {
			return fmt.Sprintf("%d+%d", a, b)
		}
		return "any other"
	}
	return fmt.Sprint(s)
}

// rollTable lists each roll result and its combined payout across the
// player's bets, one row per roll. Dice-distinguishing bets (hardways, hop)
// name their pair; everything else reads by total. Pairs that share a
// label and outcome collapse; across bets, same-roll payouts add. Tags
// stay single-level: the tag expander does not nest.
func (t *crapsTable) rollTable(p *crapsPlayer) string {
	agg := map[string]int{}
	for _, bet := range p.bets {
		perLabel := map[string]int{}
		for a := 1; a <= 6; a++ {
			for b := a; b <= 6; b++ {
				done, x, y := crapsOutcome(bet.kind, bet.number, a, b, t.point, t.Config.Craps.Field12)
				if !done {
					// Unresolved contracts stay put; only bonuses can
					// complete within a single non-settling roll.
					switch bet.kind {
					case "fire":
						x = crapsFireProfit(len(t.made))
					case "small", "tall", "all":
						lo, hi := 2, 12
						if bet.kind == "small" {
							hi = 6
						}
						if bet.kind == "tall" {
							lo = 8
						}
						if !crapsBonusComplete(lo, hi, t.seen, a+b) {
							continue
						}
						x = 34
						if bet.kind == "all" {
							x = 175
						}
					default:
						continue
					}
				}
				net := crapsNet(bet, x, y, x, crapsRefundOdds(bet, t.point))
				if net != 0 {
					perLabel[crapsRollLabel(bet, a, b)] = net
				}
			}
		}
		for label, net := range perLabel {
			agg[label] += net
		}
	}
	if len(agg) == 0 {
		if len(p.bets) == 0 {
			return "No open wagers."
		}
		return "{casino_action}Your place, buy and hardway bets are OFF on the come-out — nothing pays until a point is set.{/}"
	}
	labels := []string{}
	for label := range agg {
		labels = append(labels, label)
	}
	sort.Slice(labels, func(i, j int) bool {
		ni, nj := agg[labels[i]], agg[labels[j]]
		if (ni > 0) != (nj > 0) {
			return ni > 0
		}
		if ni != nj {
			return ni > nj
		}
		return labels[i] < labels[j]
	})
	var sb strings.Builder
	sb.WriteString("{casino_emphasis}ROLL RESULTS ON YOUR BETS{/}\n")
	for _, label := range labels {
		net := agg[label]
		tag, amount := "casino_result_loss", fmt.Sprint(net)
		if net > 0 {
			tag, amount = "casino_result_win", "+"+amount
		}
		fmt.Fprintf(&sb, "  {casino_payout}%s{/}%s {%s}%s{/}\n", label, strings.Repeat(" ", max(1, 10-len(label))), tag, amount)
	}
	sb.WriteString("{casino_action}Hardways and hops name their pair; totals cover both orders.{/}")
	return sb.String()
}