Merge pull request #69 from GenerationSoftware/gen-440-auctions-alloc…

…ate-fees-instead-of-withdrawreserve-c4-92

Auctions allocate fees instead of withdraw reserve

src/PrizePool.sol

@@ -93,6 +93,9 @@ error PrizeIsZero();
 /// @notice Emitted when someone tries to claim a prize, but sets the fee recipient address to the zero address.
 error FeeRecipientZeroAddress();
 
+/// @notice Emitted when a claim is attempted after the claiming period has expired.
+error ClaimPeriodExpired();
+
 /**
  * @notice Constructor Parameters
  * @param prizeToken The token to use for prizes
@@ -165,10 +168,10 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
     uint48 drawStartedAt
   );
 
-  /// @notice Emitted when any amount of the reserve is withdrawn.
-  /// @param to The address the assets are transferred to
-  /// @param amount The amount of assets transferred
-  event WithdrawReserve(address indexed to, uint256 amount);
+  /// @notice Emitted when any amount of the reserve is rewarded to a recipient.
+  /// @param to The recipient of the reward
+  /// @param amount The amount of assets rewarded
+  event AllocateRewardFromReserve(address indexed to, uint256 amount);
 
   /// @notice Emitted when the reserve is manually increased.
   /// @param user The user who increased the reserve
@@ -182,10 +185,11 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
   event ContributePrizeTokens(address indexed vault, uint24 indexed drawId, uint256 amount);
 
   /// @notice Emitted when an address withdraws their prize claim rewards.
+  /// @param account The account that is withdrawing rewards
   /// @param to The address the rewards are sent to
   /// @param amount The amount withdrawn
   /// @param available The total amount that was available to withdraw before the transfer
-  event WithdrawClaimRewards(address indexed to, uint256 amount, uint256 available);
+  event WithdrawRewards(address indexed account, address indexed to, uint256 amount, uint256 available);
 
   /// @notice Emitted when an address receives new prize claim rewards.
   /// @param to The address the rewards are given to
@@ -205,8 +209,8 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
   mapping(address vault => mapping(address account => mapping(uint24 drawId => mapping(uint8 tier => mapping(uint32 prizeIndex => bool claimed)))))
     internal _claimedPrizes;
 
-  /// @notice Tracks the total fees accrued to each claimer.
-  mapping(address claimer => uint256 rewards) internal _claimerRewards;
+  /// @notice Tracks the total rewards accrued for a claimer or draw completer.
+  mapping(address recipient => uint256 rewards) internal _rewards;
 
   /// @notice The degree of POOL contribution smoothing. 0 = no smoothing, ~1 = max smoothing.
   /// @dev Smoothing spreads out vault contribution over multiple draws; the higher the smoothing the more draws.
@@ -335,10 +339,10 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
     return _deltaBalance;
   }
 
-  /// @notice Allows the Manager to withdraw tokens from the reserve.
-  /// @param _to The address to send the tokens to
-  /// @param _amount The amount of tokens to withdraw
-  function withdrawReserve(address _to, uint96 _amount) external onlyDrawManager {
+  /// @notice Allows the Manager to allocate a reward from the reserve to a recipient.
+  /// @param _to The address to allocate the rewards to
+  /// @param _amount The amount of tokens for the reward
+  function allocateRewardFromReserve(address _to, uint96 _amount) external onlyDrawManager {
     if (_amount > _reserve) {
       revert InsufficientReserve(_amount, _reserve);
     }
@@ -347,8 +351,8 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
       _reserve -= _amount;
     }
 
-    _transfer(_to, _amount);
-    emit WithdrawReserve(_to, _amount);
+    _rewards[_to] += _amount;
+    emit AllocateRewardFromReserve(_to, _amount);
   }
 
   /// @notice Allows the Manager to close the current open draw and open the next one.
@@ -425,6 +429,12 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
     uint96 _fee,
     address _feeRecipient
   ) external returns (uint256) {
+    /// @dev Claims cannot occur after the draw auctions have begun for the open draw since a claim might dip into
+    /// the reserve and cause auction results to be inaccurate. By limiting the claim period to 1 period after the
+    /// draw ends, we provide a predictable environment for draw auctions to operate in.
+    if (block.timestamp >= _openDrawEndsAt()) {
+      revert ClaimPeriodExpired();
+    }
     if (_feeRecipient == address(0) && _fee > 0) {
       revert FeeRecipientZeroAddress();
     }
@@ -480,7 +490,7 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
     uint256 amount;
     if (_fee != 0) {
       emit IncreaseClaimRewards(_feeRecipient, _fee);
-      _claimerRewards[_feeRecipient] += _fee;
+      _rewards[_feeRecipient] += _fee;
 
       unchecked {
         amount = tierLiquidity.prizeSize - _fee;
@@ -511,23 +521,23 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
   }
 
   /**
-   * @notice Withdraws the claim fees for the caller.
-   * @param _to The address to transfer the claim fees to.
-   * @param _amount The amount of claim fees to withdraw
+   * @notice Withdraws earned rewards for the caller.
+   * @param _to The address to transfer the rewards to
+   * @param _amount The amount of rewards to withdraw
    */
-  function withdrawClaimRewards(address _to, uint256 _amount) external {
-    uint256 _available = _claimerRewards[msg.sender];
+  function withdrawRewards(address _to, uint256 _amount) external {
+    uint256 _available = _rewards[msg.sender];
 
     if (_amount > _available) {
       revert InsufficientRewardsError(_amount, _available);
     }
 
     unchecked {
-      _claimerRewards[msg.sender] = _available - _amount;
+      _rewards[msg.sender] = _available - _amount;
     }
 
     _transfer(_to, _amount);
-    emit WithdrawClaimRewards(_to, _amount, _available);
+    emit WithdrawRewards(msg.sender, _to, _amount, _available);
   }
 
   /// @notice Allows anyone to deposit directly into the Prize Pool reserve.
@@ -686,12 +696,12 @@ contract PrizePool is TieredLiquidityDistributor, Ownable {
   }
 
   /**
-   * @notice Returns the balance of fees for a given claimer
-   * @param _claimer The claimer to retrieve the fee balance for
-   * @return The balance of fees for the given claimer
+   * @notice Returns the balance of rewards earned for the given address.
+   * @param _recipient The recipient to retrieve the reward balance for
+   * @return The balance of rewards for the given recipient
    */
-  function balanceOfClaimRewards(address _claimer) external view returns (uint256) {
-    return _claimerRewards[_claimer];
+  function rewardBalance(address _recipient) external view returns (uint256) {
+    return _rewards[_recipient];
   }
 
   /**