feat: single-owner game state, transactional lifecycle, durable money on server stop

1 files changed, 57 insertions, 10 deletions

diff --git a/internal/game/casino.go b/internal/game/casino.go
index eb6fa4a..7442178 100644
--- a/internal/game/casino.go
+++ b/internal/game/casino.go
@@ -18,29 +18,76 @@ type casinoWallet struct {
 	p *player.Player
 }
 
-func (w casinoWallet) Wager(amount int) (casino.Wager, bool) {
+// Wager debits the stake durably. Order of operations: durable journal
+// record FIRST (with balance checkpoints), then the in-memory mutation,
+// then the character save, then the settlement marker. A failed save
+// reverts the in-memory mutation and voids the record: no charge is kept
+// in memory, and the error distinguishes persistence failure from
+// insufficient funds.
+func (w casinoWallet) Wager(amount int) (casino.Wager, error) {
 	if amount <= 0 {
-		return casino.Wager{}, false
+		return casino.Wager{}, casino.ErrInsufficientFunds
 	}
-	chips := countChips(w.p)
+	creditsBefore := w.p.Credits
+	chipsBefore := countChips(w.p)
+	chips := chipsBefore
 	if chips > amount {
 		chips = amount
 	}
 	credits := amount - chips
-	if w.p.Credits < credits {
-		return casino.Wager{}, false
+	if creditsBefore < credits {
+		return casino.Wager{}, casino.ErrInsufficientFunds
+	}
+	rec, err := w.g.Economy.start("wager", w.p, chips, credits,
+		creditsBefore, creditsBefore-credits, chipsBefore, chipsBefore-chips)
+	if err != nil {
+		return casino.Wager{}, casino.ErrWalletPersistence
 	}
 	if chips > 0 {
 		w.p.RemoveItem("chips", chips)
 	}
 	w.p.Credits -= credits
-	w.g.AccountStore.SaveCharacter(w.p)
-	return casino.Wager{Total: amount, Chips: chips, Credits: credits}, true
+	if err := w.g.AccountStore.SaveCharacter(w.p); err != nil {
+		// Revert the in-memory mutation: the play must not proceed on a
+		// stake that could not be made durable.
+		if chips > 0 {
+			w.g.giveChips(w.p, chips)
+		}
+		w.p.Credits += credits
+		w.g.Economy.void(rec)
+		return casino.Wager{}, casino.ErrWalletPersistence
+	}
+	w.g.Economy.settle(rec)
+	return casino.Wager{Total: amount, Chips: chips, Credits: credits}, nil
 }
 
-func (w casinoWallet) PayCredits(amount int) {
-	w.p.Credits += amount
-	w.g.AccountStore.SaveCharacter(w.p)
+// PayCredits applies a payout durably. The journal record is written first;
+// if the save fails, the record stays open and startup recovery re-pays it
+// (the player is owed the settlement).
+func (w casinoWallet) PayCredits(amount int) error {
+	if amount <= 0 {
+		return nil
+	}
+	creditsBefore := w.p.Credits
+	chipsBefore := countChips(w.p)
+	creditsAfter, err := addCreditsChecked(creditsBefore, amount)
+	if err != nil {
+		return err
+	}
+	rec, err := w.g.Economy.start("payout", w.p, 0, amount,
+		creditsBefore, creditsAfter, chipsBefore, chipsBefore)
+	if err != nil {
+		return casino.ErrWalletPersistence
+	}
+	w.p.Credits = creditsAfter
+	if err := w.g.AccountStore.SaveCharacter(w.p); err != nil {
+		w.p.Credits = creditsBefore
+		// Keep the record open: recovery re-pays on next startup, since a
+		// reported win must be durable.
+		return casino.ErrWalletPersistence
+	}
+	w.g.Economy.settle(rec)
+	return nil
 }
 
 // casinoAffordable is the most a player can wager: chips are spent first,