_distributeExcessIdle overhaul

contracts/src/external/HyperdriveTarget0.sol

@@ -12,7 +12,7 @@ import { HyperdriveShort } from "../internal/HyperdriveShort.sol";
 import { HyperdriveStorage } from "../internal/HyperdriveStorage.sol";
 import { AssetId } from "../libraries/AssetId.sol";
 import { FixedPointMath } from "../libraries/FixedPointMath.sol";
-import { HyperdriveMath } from "../libraries/HyperdriveMath.sol";
+import { LPMath } from "../libraries/LPMath.sol";
 
 /// @author DELV
 /// @title HyperdriveTarget0
@@ -267,7 +267,7 @@ abstract contract HyperdriveTarget0 is
             _totalSupply[AssetId._WITHDRAWAL_SHARE_ASSET_ID] -
             _withdrawPool.readyToWithdraw;
         uint256 presentValue = sharePrice > 0
-            ? HyperdriveMath
+            ? LPMath
                 .calculatePresentValue(_getPresentValueParams(sharePrice))
                 .mulDown(sharePrice)
             : 0;

contracts/src/internal/HyperdriveBase.sol

@@ -6,6 +6,7 @@ import { IHyperdrive } from "../interfaces/IHyperdrive.sol";
 import { AssetId } from "../libraries/AssetId.sol";
 import { FixedPointMath, ONE } from "../libraries/FixedPointMath.sol";
 import { HyperdriveMath } from "../libraries/HyperdriveMath.sol";
+import { LPMath } from "../libraries/LPMath.sol";
 import { SafeCast } from "../libraries/SafeCast.sol";
 import { HyperdriveStorage } from "./HyperdriveStorage.sol";
 
@@ -258,17 +259,49 @@ abstract contract HyperdriveBase is HyperdriveStorage {
             );
     }
 
+    /// @dev Gets the distribute excess idle parameters from the current state.
+    /// @param _sharePrice The current share price.
+    /// @return params The distribute excess idle parameters.
+    function _getDistributeExcessIdleParams(
+        uint256 _idle,
+        uint256 _withdrawalSharesTotalSupply,
+        uint256 _sharePrice
+    ) internal view returns (LPMath.DistributeExcessIdleParams memory params) {
+        LPMath.PresentValueParams
+            memory presentValueParams = _getPresentValueParams(_sharePrice);
+        uint256 startingPresentValue = LPMath.calculatePresentValue(
+            presentValueParams
+        );
+        int256 netCurveTrade = int256(
+            presentValueParams.longsOutstanding.mulDown(
+                presentValueParams.longAverageTimeRemaining
+            )
+        ) -
+            int256(
+                presentValueParams.shortsOutstanding.mulDown(
+                    presentValueParams.shortAverageTimeRemaining
+                )
+            );
+        params = LPMath.DistributeExcessIdleParams({
+            presentValueParams: presentValueParams,
+            startingPresentValue: startingPresentValue,
+            activeLpTotalSupply: _totalSupply[AssetId._LP_ASSET_ID],
+            withdrawalSharesTotalSupply: _withdrawalSharesTotalSupply,
+            idle: _idle,
+            netCurveTrade: netCurveTrade,
+            originalShareReserves: presentValueParams.shareReserves,
+            originalShareAdjustment: presentValueParams.shareAdjustment,
+            originalBondReserves: presentValueParams.bondReserves
+        });
+    }
+
     /// @dev Gets the present value parameters from the current state.
     /// @param _sharePrice The current share price.
-    /// @return presentValue The present value parameters.
+    /// @return params The present value parameters.
     function _getPresentValueParams(
         uint256 _sharePrice
-    )
-        internal
-        view
-        returns (HyperdriveMath.PresentValueParams memory presentValue)
-    {
-        presentValue = HyperdriveMath.PresentValueParams({
+    ) internal view returns (LPMath.PresentValueParams memory params) {
+        params = LPMath.PresentValueParams({
             shareReserves: _marketState.shareReserves,
             shareAdjustment: _marketState.shareAdjustment,
             bondReserves: _marketState.bondReserves,
@@ -364,6 +397,8 @@ abstract contract HyperdriveBase is HyperdriveStorage {
     /// @dev Calculates the number of share reserves that are not reserved by
     ///      open positions.
     /// @param _sharePrice The current share price.
+    /// @return idleShares The amount of shares that are available for LPs to
+    ///         withdraw.
     function _calculateIdleShareReserves(
         uint256 _sharePrice
     ) internal view returns (uint256 idleShares) {
@@ -379,6 +414,26 @@ abstract contract HyperdriveBase is HyperdriveStorage {
         return idleShares;
     }
 
+    /// @dev Calculates the LP share price.
+    /// @param _sharePrice The current share price.
+    /// @return lpSharePrice The LP share price.
+    function _calculateLPSharePrice(
+        uint256 _sharePrice
+    ) internal view returns (uint256 lpSharePrice) {
+        uint256 presentValue = _sharePrice > 0
+            ? LPMath
+                .calculatePresentValue(_getPresentValueParams(_sharePrice))
+                .mulDown(_sharePrice)
+            : 0;
+        uint256 lpTotalSupply = _totalSupply[AssetId._LP_ASSET_ID] +
+            _totalSupply[AssetId._WITHDRAWAL_SHARE_ASSET_ID] -
+            _withdrawPool.readyToWithdraw;
+        lpSharePrice = lpTotalSupply == 0
+            ? 0
+            : presentValue.divDown(lpTotalSupply);
+        return lpSharePrice;
+    }
+
     /// @dev Calculates the fees that go to the LPs and governance.
     /// @param _shareAmount The amount of shares exchanged for bonds.
     /// @param _spotPrice The price without slippage of bonds in terms of base
@@ -496,7 +551,8 @@ abstract contract HyperdriveBase is HyperdriveStorage {
             flatFee.mulDown(_governanceFee);
     }
 
-    /// @dev Converts input to base if necessary according to what is specified in options.
+    /// @dev Converts input to base if necessary according to what is specified
+    ///      in options.
     /// @param _amount The amount to convert.
     /// @param _sharePrice The current share price.
     /// @param _options The options that configure the conversion.

contracts/src/internal/HyperdriveCheckpoint.sol

@@ -5,6 +5,7 @@ import { IHyperdrive } from "../interfaces/IHyperdrive.sol";
 import { AssetId } from "../libraries/AssetId.sol";
 import { FixedPointMath } from "../libraries/FixedPointMath.sol";
 import { HyperdriveMath } from "../libraries/HyperdriveMath.sol";
+import { LPMath } from "../libraries/LPMath.sol";
 import { SafeCast } from "../libraries/SafeCast.sol";
 import { HyperdriveBase } from "./HyperdriveBase.sol";
 import { HyperdriveLong } from "./HyperdriveLong.sol";
@@ -187,23 +188,12 @@ abstract contract HyperdriveCheckpoint is
 
         // Emit an event about the checkpoint creation that includes the LP
         // share price.
-        uint256 presentValue = _sharePrice > 0
-            ? HyperdriveMath
-                .calculatePresentValue(_getPresentValueParams(_sharePrice))
-                .mulDown(_sharePrice)
-            : 0;
-        uint256 lpTotalSupply = _totalSupply[AssetId._LP_ASSET_ID] +
-            _totalSupply[AssetId._WITHDRAWAL_SHARE_ASSET_ID] -
-            _withdrawPool.readyToWithdraw;
-        uint256 lpSharePrice = lpTotalSupply == 0
-            ? 0
-            : presentValue.divDown(lpTotalSupply);
         emit CreateCheckpoint(
             _checkpointTime,
             _sharePrice,
             maturedShortsAmount,
             maturedLongsAmount,
-            lpSharePrice
+            _calculateLPSharePrice(_sharePrice)
         );
 
         return _sharePrice;