PULL THE LEVER_

// the entire casino, distilled
function afterSwap(
  address sender,
  PoolKey calldata key,
  IPoolManager.SwapParams calldata p,
  BalanceDelta delta
) external override returns (bytes4) {

  // 1. only count buys (eth → u777)
  if (p.zeroForOne) {
      uint256 fee = _feeOf(delta);
      // 2. divert 10% of fee → jackpot vault
      jackpot[currentEpoch] += fee / 10;

      // 3. mint a weighted lottery ticket
      uint256 weight = _rollTier(sender, fee);
      tickets.mint(sender, currentEpoch, weight);
  }

  // 4. is it draw time?
  if (block.timestamp >= drawAt) {
      address winner = _pickWinner(currentEpoch);
      _payout(winner, jackpot[currentEpoch]);
      _rollEpoch();
  }

  return BaseHook.afterSwap.selector;
}