Break the lock. Take the loot.BREAK THE LOCK.TAKE THE LOOT.

export function qualifies(trade: Trade, rules: Rules): boolean {
  return (
    trade.side === "buy" &&
    trade.lamports >= rules.minBuyLamports &&
    !rules.excluded.has(trade.wallet)
  );
}

export function applyTrade(round: Round, trade: Trade, rules: Rules): Step {
  // Every trade, buy or sell, pays its creator fee into the vault.
  const vault = round.vaultLamports + trade.feeLamports;
  const full = vault >= rules.thresholdLamports;
  const crackedNow = full && !round.cracked;

  // The first qualifying buy once the vault is full breaks the lock.
  if (full && qualifies(trade, rules)) {
    const breaker = splitShare(vault, rules.breakerBps);
    return {
      round: startRound(round.lock + 1),
      cracked: crackedNow,
      broke: {
        lock: round.lock,
        winner: trade.wallet,
        sig: trade.sig,
        winnerTokens: trade.tokens,
        lootLamports: vault,
        breakerLamports: breaker,
        burnLamports: vault - breaker, // bought back and burned
        ts: trade.ts,
      },
    };
  }

  // A sell or a small buy can fill it: the lock cracks and waits.
  return {
    round: { ...round, vaultLamports: vault, cracked: full, trades: round.trades + 1 },
    cracked: crackedNow,
  };
}