1 files changed, 307 insertions, 0 deletions
diff --git a/internal/casino/video_poker_rules.go b/internal/casino/video_poker_rules.go
new file mode 100644
index 0000000..340815d
--- /dev/null
+++ b/internal/casino/video_poker_rules.go
@@ -0,0 +1,307 @@
+package casino
+
+import (
+	"strings"
+	"unicode"
+)
+
+type pokerSchedule struct {
+	name string
+	pays map[string]int
+}
+
+// pokerCategories is the fixed pay-table row order, top payout first.
+var pokerCategories = []string{"Natural royal flush", "Royal flush", "Four deuces", "Five of a kind", "Wild royal flush", "Straight flush", "Four aces with 2-4 kicker", "Four 2s-4s with A-4 kicker", "Four aces", "Four 2s-4s", "Four 5s-Ks", "Four of a kind", "Full house", "Flush", "Straight", "Three of a kind", "Two pair", "Jacks or better", "Kings or better"}
+
+// pokerPayTable resolves the per-coin (five-coin) rates for a resolved
+// game/pay-table pair. Every listed schedule is a published one; see
+// building_guide/video_poker.md for the sources.
+func pokerPayTable(c VideoPokerConfig) (pokerSchedule, bool) {
+	c = c.Normalize()
+	if c.Variant == "" {
+		return pokerSchedule{}, false
+	}
+	p := map[string]int{"Royal flush": 800, "Straight flush": 50, "Four of a kind": 25, "Straight": 4, "Three of a kind": 3, "Two pair": 2, "Jacks or better": 1}
+	name := variantTitle(c.Variant)
+	switch c.Variant {
+	case "jacks_or_better":
+		if !switchTwo(&p, c.PayTable, map[string][2]int{"9/6": {9, 6}, "9/5": {9, 5}, "8/6": {8, 6}, "8/5": {8, 5}, "7/5": {7, 5}}) {
+			return pokerSchedule{}, false
+		}
+	case "bonus_poker":
+		if !switchTwo(&p, c.PayTable, map[string][2]int{"8/5": {8, 5}, "7/5": {7, 5}, "6/5": {6, 5}}) {
+			return pokerSchedule{}, false
+		}
+		p["Four aces"], p["Four 2s-4s"], p["Four 5s-Ks"] = 80, 40, 25
+		delete(p, "Four of a kind")
+	case "bonus_poker_deluxe":
+		if !switchTwo(&p, c.PayTable, map[string][2]int{"9/6": {9, 6}, "9/5": {9, 5}, "8/6": {8, 6}, "8/5": {8, 5}, "7/5": {7, 5}}) {
+			return pokerSchedule{}, false
+		}
+		p["Four of a kind"], p["Two pair"] = 80, 1
+	case "double_bonus", "double_double_bonus":
+		p["Two pair"] = 1
+		delete(p, "Four of a kind")
+		p["Four aces"], p["Four 2s-4s"], p["Four 5s-Ks"] = 160, 80, 50
+		if c.Variant == "double_bonus" {
+			p["Straight"] = 5
+			switch c.PayTable {
+			case "10/7":
+				p["Full house"], p["Flush"] = 10, 7
+			case "9/7":
+				p["Full house"], p["Flush"] = 9, 7
+			case "9/6/5":
+				p["Full house"], p["Flush"] = 9, 6
+			case "9/6/4":
+				p["Full house"], p["Flush"], p["Straight"] = 9, 6, 4
+			case "9/5/4":
+				p["Full house"], p["Flush"], p["Straight"] = 9, 5, 4
+			case "8/5":
+				p["Full house"], p["Flush"], p["Straight"] = 8, 5, 4
+			default:
+				return pokerSchedule{}, false
+			}
+		} else {
+			name = "Double Double Bonus"
+			p["Four aces with 2-4 kicker"], p["Four 2s-4s with A-4 kicker"] = 400, 160
+			switch c.PayTable {
+			case "10/6":
+				p["Full house"], p["Flush"] = 10, 6
+			case "9/6":
+				p["Full house"], p["Flush"] = 9, 6
+			case "9/5":
+				p["Full house"], p["Flush"] = 9, 5
+			case "8/6":
+				p["Full house"], p["Flush"] = 8, 6
+			case "8/5":
+				p["Full house"], p["Flush"] = 8, 5
+			default:
+				return pokerSchedule{}, false
+			}
+		}
+	case "deuces_wild":
+		name = "Deuces Wild"
+		p = map[string]int{"Natural royal flush": 800, "Four deuces": 200, "Wild royal flush": 25, "Five of a kind": 15, "Straight flush": 9, "Four of a kind": 5, "Full house": 3, "Flush": 2, "Straight": 2, "Three of a kind": 1}
+		switch c.PayTable {
+		case "25/15/9/5/3/2":
+		case "25/15/9/4/4/3":
+			p["Four of a kind"], p["Full house"], p["Flush"] = 4, 4, 3
+		case "25/16/13/4/3/2":
+			p["Five of a kind"], p["Straight flush"], p["Four of a kind"] = 16, 13, 4
+		case "20/12/10/4/4/3":
+			p["Wild royal flush"], p["Five of a kind"], p["Straight flush"], p["Four of a kind"], p["Full house"], p["Flush"] = 20, 12, 10, 4, 4, 3
+		default:
+			return pokerSchedule{}, false
+		}
+	case "joker_poker":
+		if c.PayTable != "50/17/7/5/3" && c.PayTable != "50/16/7/5/3" && c.PayTable != "50/15/7/5/3" {
+			return pokerSchedule{}, false
+		}
+		name = "Joker Poker (Kings or Better)"
+		p = map[string]int{"Natural royal flush": 800, "Five of a kind": 200, "Wild royal flush": 100, "Straight flush": 50, "Four of a kind": 17, "Full house": 7, "Flush": 5, "Straight": 3, "Three of a kind": 2, "Two pair": 1, "Kings or better": 1}
+		if c.PayTable == "50/16/7/5/3" {
+			p["Four of a kind"] = 16
+		}
+		if c.PayTable == "50/15/7/5/3" {
+			p["Four of a kind"] = 15
+		}
+	default:
+		return pokerSchedule{}, false
+	}
+	return pokerSchedule{name + " / " + c.PayTable, p}, true
+}
+
+// switchTwo applies a full-house/flush pair to the schedule map and reports
+// whether the pay-table name was one of the listed editions.
+func switchTwo(p *map[string]int, payTable string, editions map[string][2]int) bool {
+	if edition, ok := editions[payTable]; ok {
+		(*p)["Full house"], (*p)["Flush"] = edition[0], edition[1]
+		return true
+	}
+	return false
+}
+
+func pokerRules(c VideoPokerConfig) string {
+	c = c.Normalize()
+	schedule, ok := pokerPayTable(c)
+	if !ok {
+		return "This cabinet is not configured with a playable game."
+	}
+	lines := []string{c.CabinetLabel() + " / " + schedule.name,
+		"One fresh deck per deal. bet 1-4 loads coins (up to five per hand);",
+		"bet max loads five. Bare bet repeats the previous selection. deal",
+		"charges the full wager and deals; numbers toggle holds; d draws.",
+		"denom 1|10|50 sets credits per coin. paytable shows this box again.",
+		"Payouts are total coins per hand (stake included), not profit odds.",
+		c.PairRule(),
+	}
+	if c.Feature != "" {
+		lines = append(lines, c.FeatureRules())
+	}
+	lines = append(lines, "Only the highest-paying category pays on each line.")
+	return strings.Join(lines, "\n")
+}
+
+// PairRule names the lowest paying hand family of the selected game.
+func (c VideoPokerConfig) PairRule() string {
+	c = c.Normalize()
+	switch c.Variant {
+	case "deuces_wild":
+		return "Every 2 is wild. Three of a kind is the lowest win; only the highest category pays."
+	case "joker_poker":
+		return "One joker is wild. A pair of kings or aces is the lowest win; a wild royal is not a natural royal."
+	case "bonus_poker", "bonus_poker_deluxe", "double_bonus", "double_double_bonus":
+		return "A pair of jacks or better is the lowest win; four of a kind carries bonus rates by rank."
+	}
+	return "A pair of jacks or better is the lowest win."
+}
+
+// ParsePokerDigits accepts the unordered digits of a hold selection: every
+// distinct digit toggles that card once per command; spacing and order do not matter.
+func ParsePokerDigits(input string) ([]int, bool) {
+	var digits []int
+	var seen [5]bool
+	for _, r := range input {
+		if unicode.IsSpace(r) {
+			continue
+		}
+		if r < '1' || r > '5' {
+			return nil, false
+		}
+		i := int(r - '1')
+		if !seen[i] {
+			digits = append(digits, i)
+			seen[i] = true
+		}
+	}
+	return digits, len(digits) > 0
+}
+
+func pokerRank(c card) int {
+	switch c.rank {
+	case "A":
+		return 14
+	case "K":
+		return 13
+	case "Q":
+		return 12
+	case "J":
+		return 11
+	}
+	return c.blackjackValue()
+}
+
+// evaluatePoker scores one five-card line against the resolved schedule. Wild
+// evaluation uses rank deficits instead of enumerating wild-card assignments.
+func evaluatePoker(cards [5]card, cfg VideoPokerConfig) (string, int) {
+	cfg = cfg.Normalize()
+	schedule, ok := pokerPayTable(cfg)
+	if !ok {
+		return "No win", 0
+	}
+	counts := [15]int{}
+	wild := 0
+	suit := ""
+	flush := true
+	for _, c := range cards {
+		r := pokerRank(c)
+		if cfg.Variant == "deuces_wild" && r == 2 || cfg.Variant == "joker_poker" && c.rank == "JK" {
+			wild++
+			continue
+		}
+		counts[r]++
+		if suit == "" {
+			suit = c.suit
+		} else if suit != c.suit {
+			flush = false
+		}
+	}
+	straight, royal := false, false
+	for high := 5; high <= 14; high++ {
+		fits := true
+		for r := 2; r <= 14; r++ {
+			if counts[r] == 0 {
+				continue
+			}
+			in := r >= high-4 && r <= high
+			if high == 5 && r == 14 {
+				in = true
+			}
+			if !in || counts[r] > 1 {
+				fits = false
+				break
+			}
+		}
+		if fits {
+			straight = true
+			if high == 14 {
+				royal = true
+			}
+		}
+	}
+	maxCount, quad, kicker, pairs := 0, 0, 0, 0
+	for r := 2; r <= 14; r++ {
+		if counts[r] > maxCount {
+			maxCount = counts[r]
+		}
+		if counts[r] == 4 {
+			quad = r
+		}
+		if counts[r] == 1 {
+			kicker = r
+		}
+		if counts[r] == 2 {
+			pairs++
+		}
+	}
+	var candidates []string
+	add := func(ok bool, k string) {
+		if ok {
+			candidates = append(candidates, k)
+		}
+	}
+	if cfg.Variant == "deuces_wild" || cfg.Variant == "joker_poker" {
+		add(flush && royal && wild == 0, "Natural royal flush")
+		add(cfg.Variant == "deuces_wild" && wild == 4, "Four deuces")
+		add(flush && royal && wild > 0, "Wild royal flush")
+		add(maxCount+wild >= 5, "Five of a kind")
+		add(maxCount+wild >= 4, "Four of a kind")
+		if cfg.Variant == "joker_poker" {
+			add(pairs == 2 || pairs == 1 && wild == 1, "Two pair")
+			add(counts[13]+wild >= 2 || counts[14]+wild >= 2, "Kings or better")
+		}
+	} else {
+		add(flush && royal, "Royal flush")
+		add(quad > 0, "Four of a kind")
+		add(quad == 14, "Four aces")
+		add(quad >= 2 && quad <= 4, "Four 2s-4s")
+		add(quad >= 5 && quad <= 13, "Four 5s-Ks")
+		add(quad == 14 && kicker >= 2 && kicker <= 4, "Four aces with 2-4 kicker")
+		add(quad >= 2 && quad <= 4 && (kicker == 14 || kicker >= 2 && kicker <= 4), "Four 2s-4s with A-4 kicker")
+		add(pairs == 2, "Two pair")
+		add(counts[11] == 2 || counts[12] == 2 || counts[13] == 2 || counts[14] == 2, "Jacks or better")
+	}
+	full := false
+	for a := 2; a <= 14; a++ {
+		for b := 2; b <= 14; b++ {
+			if a == b || counts[a] > 3 || counts[b] > 2 {
+				continue
+			}
+			if counts[a]+counts[b]+wild == 5 {
+				full = true
+			}
+		}
+	}
+	add(flush && straight, "Straight flush")
+	add(full, "Full house")
+	add(flush, "Flush")
+	add(straight, "Straight")
+	add(maxCount+wild >= 3, "Three of a kind")
+	best, pay := "No win", 0
+	for _, k := range candidates {
+		if schedule.pays[k] > pay {
+			best, pay = k, schedule.pays[k]
+		}
+	}
+	return best, pay
+}