Merge pull request #278 from stabilitydao/276-sial-support-swapx-flashloan

276 sial support swapx flashloan

Author: a17

src/integrations/algebrav4/callback/IAlgebraFlashCallback.sol

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.23;
+
+/// @title Callback for IAlgebraPoolActions#flash
+/// @notice Any contract that calls IAlgebraPoolActions#flash must implement this interface
+/// @dev Credit to Uniswap Labs under GPL-2.0-or-later license:
+/// https://github.com/Uniswap/v3-core/tree/main/contracts/interfaces
+interface IAlgebraFlashCallback {
+  /// @notice Called to `msg.sender` after transferring to the recipient from IAlgebraPool#flash.
+  /// @dev In the implementation you must repay the pool the tokens sent by flash plus the computed fee amounts.
+  /// The caller of this method _must_ be checked to be a AlgebraPool deployed by the canonical AlgebraFactory.
+  /// @param fee0 The fee amount in token0 due to the pool by the end of the flash
+  /// @param fee1 The fee amount in token1 due to the pool by the end of the flash
+  /// @param data Any data passed through by the caller via the IAlgebraPoolActions#flash call
+  function algebraFlashCallback(uint256 fee0, uint256 fee1, bytes calldata data) external;
+}

src/interfaces/IControllable.sol

@@ -25,6 +25,7 @@ interface IControllable {
     error IncorrectInitParams();
     error InsufficientBalance();
     error IncorrectLtv(uint ltv);
+    error TooLowValue(uint value);
     //endregion -- Custom Errors -----
 
     event ContractInitialized(address platform, uint ts, uint block);

src/interfaces/ILeverageLendingStrategy.sol

@@ -93,7 +93,8 @@ interface ILeverageLendingStrategy {
         /// @notice Balancer V2
         Default_0,
         BalancerV3_1,
-        UniswapV3_2
+        UniswapV3_2,
+        AlgebraV4_3
     }
 
     /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/

src/strategies/SiloAdvancedLeverageStrategy.sol

@@ -18,6 +18,7 @@ import {ISilo} from "../integrations/silo/ISilo.sol";
 import {IStrategy} from "../interfaces/IStrategy.sol";
 import {IVaultMainV3} from "../integrations/balancerv3/IVaultMainV3.sol";
 import {IUniswapV3FlashCallback} from "../integrations/uniswapv3/IUniswapV3FlashCallback.sol";
+import {IAlgebraFlashCallback} from "../integrations/algebrav4/callback/IAlgebraFlashCallback.sol";
 import {IBalancerV3FlashCallback} from "../integrations/balancerv3/IBalancerV3FlashCallback.sol";
 import {LeverageLendingBase} from "./base/LeverageLendingBase.sol";
 import {Math} from "@openzeppelin/contracts/utils/math/Math.sol";
@@ -30,6 +31,12 @@ import {XStaking} from "../tokenomics/XStaking.sol";
 
 /// @title Silo V2 advanced leverage strategy
 /// Changelog:
+///   2.1.0:
+///     + support of algebra-v4 flash loan #276
+///     * reduce amount of swap in withdraw
+///     * use withdrawParam0 in deposit to fit result leverage
+///     * check ltv on exit of deposit
+///     * use LeverageLendingBase 1.2.1 #277
 ///   2.0.0:
 ///     * bug: decreasing LTV on exits #254
 ///     * bug: deposit logic must use oracle price #247
@@ -45,7 +52,8 @@ contract SiloAdvancedLeverageStrategy is
     LeverageLendingBase,
     IFlashLoanRecipient,
     IUniswapV3FlashCallback,
-    IBalancerV3FlashCallback
+    IBalancerV3FlashCallback,
+    IAlgebraFlashCallback
 {
     using SafeERC20 for IERC20;
 
@@ -54,7 +62,7 @@ contract SiloAdvancedLeverageStrategy is
     /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
 
     /// @inheritdoc IControllable
-    string public constant VERSION = "2.0.0";
+    string public constant VERSION = "2.1.0";
 
     /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
     /*                       INITIALIZATION                       */
@@ -151,6 +159,14 @@ contract SiloAdvancedLeverageStrategy is
         LeverageLendingBaseStorage storage $ = _getLeverageLendingBaseStorage();
         SiloAdvancedLib.receiveFlashLoan(platform(), $, token, amount, isToken0 ? fee0 : fee1);
     }
+
+    function algebraFlashCallback(uint fee0, uint fee1, bytes calldata userData) external {
+        // sender is the pool, it's checked inside receiveFlashLoan
+        (address token, uint amount, bool isToken0) = abi.decode(userData, (address, uint, bool));
+
+        LeverageLendingBaseStorage storage $ = _getLeverageLendingBaseStorage();
+        SiloAdvancedLib.receiveFlashLoan(platform(), $, token, amount, isToken0 ? fee0 : fee1);
+    }
     //endregion ----------------------------------- Flash loan
 
     //region ----------------------------------- View
@@ -340,7 +356,7 @@ contract SiloAdvancedLeverageStrategy is
         LeverageLendingBaseStorage storage $ = _getLeverageLendingBaseStorage();
         StrategyBaseStorage storage $base = _getStrategyBaseStorage();
         address[] memory _assets = assets();
-        value = SiloAdvancedLib.depositAssets($, $base, amounts[0], _assets[0]);
+        value = SiloAdvancedLib.depositAssets(platform(), $, $base, amounts[0], _assets[0]);
     }
 
     /// @inheritdoc StrategyBase

src/strategies/base/LeverageLendingBase.sol

@@ -13,6 +13,7 @@ import {IControllable} from "../../interfaces/IControllable.sol";
 
 /// @notice Base strategy for leverage lending
 /// Changelog:
+///   1.2.1: rebalanceDebt reverts if result share price less #277
 ///   1.2.0: feat: return new share price by rebalanceDebt #256; feat: use BeetsV3 OR UniswapV3-like DeX free flash loans #268
 ///   1.1.1: StrategyBase 2.1.3
 ///   1.1.0: targetLeveragePercent setup in strategy initializer; 8 universal configurable params
@@ -62,8 +63,6 @@ abstract contract LeverageLendingBase is StrategyBase, ILeverageLendingStrategy
 
     /// @inheritdoc ILeverageLendingStrategy
     function rebalanceDebt(uint newLtv, uint minSharePrice) external returns (uint resultLtv, uint resultSharePrice) {
-        minSharePrice; // todo use below
-
         IPlatform _platform = IPlatform(platform());
         IHardWorker hardworker = IHardWorker(_platform.hardWorker());
         address rebalancer = _platform.rebalancer();
@@ -76,6 +75,7 @@ abstract contract LeverageLendingBase is StrategyBase, ILeverageLendingStrategy
 
         resultLtv = _rebalanceDebt(newLtv);
         (resultSharePrice,) = _realSharePrice();
+        require(resultSharePrice >= minSharePrice, IControllable.TooLowValue(resultSharePrice));
     }
 
     /// @inheritdoc ILeverageLendingStrategy

src/strategies/libs/SiloAdvancedLib.sol

@@ -124,10 +124,6 @@ library SiloAdvancedLib {
                 collateralAmountTotal -= collateralAmountTotal / 1000;
                 ISilo(lendingVault).withdraw(
                     Math.min(tempCollateralAmount, collateralAmountTotal),
-                    // todo
-                    //                    _estimateCollateralAmountToRepay(
-                    //                        platform, collateralAmountTotal, collateralAsset, token, tempCollateralAmount
-                    //                    ),
                     address(this),
                     address(this),
                     ISilo.CollateralType.Collateral
@@ -139,10 +135,14 @@ library SiloAdvancedLib {
                 platform,
                 collateralAsset,
                 token,
-                Math.min(tempCollateralAmount, StrategyLib.balance(collateralAsset)),
+                _estimateSwapAmount(platform, amount + feeAmount, collateralAsset, token, swapPriceImpactTolerance0),
+                // Math.min(tempCollateralAmount, StrategyLib.balance(collateralAsset)),
                 swapPriceImpactTolerance0
             );
 
+            // explicit error for the case when _estimateSwapAmount gives incorrect amount
+            require(IERC20(token).balanceOf(address(this)) >= amount + feeAmount, IControllable.InsufficientBalance());
+
             // pay flash loan
             IERC20(token).safeTransfer(flashLoanVault, amount + feeAmount);
 
@@ -492,8 +492,12 @@ library SiloAdvancedLib {
             );
 
             IVaultMainV3(payable(vault)).unlock(data);
-        } else if (flashLoanKind == ILeverageLendingStrategy.FlashLoanKind.UniswapV3_2) {
-            // ensure that the vault has available amount
+        } else if (
+            // assume here that Algebra uses exactly same API as UniswapV3
+            flashLoanKind == ILeverageLendingStrategy.FlashLoanKind.UniswapV3_2
+                || flashLoanKind == ILeverageLendingStrategy.FlashLoanKind.AlgebraV4_3
+        ) {
+            // ensure that the pool has available amount
             require(
                 IERC20(flashAssets[0]).balanceOf(address(vault)) >= flashAmounts[0], IControllable.InsufficientBalance()
             );
@@ -511,26 +515,31 @@ library SiloAdvancedLib {
         }
     }
 
-    function _estimateCollateralAmountToRepay(
+    /// @notice Estimate amount of collateral to swap to receive {amountToRepay} on balance
+    /// @param priceImpactTolerance Price impact tolerance. Must include fees at least. Denominator is 100_000.
+    function _estimateSwapAmount(
         address platform,
         uint amountToRepay,
         address collateralAsset,
         address token,
-        uint tempCollateralAmount
+        uint priceImpactTolerance
     ) internal view returns (uint) {
         // We have collateral C = C1 + C2 where C1 is amount to withdraw, C2 is amount to swap to B (to repay)
         // We don't need to swap whole C, we can swap only C2 with same addon (i.e. 10%) for safety
 
         ISwapper swapper = ISwapper(IPlatform(platform).swapper());
+        uint requiredAmount = amountToRepay - IERC20(token).balanceOf(address(this));
 
-        // 10% for price impact and slippage
-        uint minCollateralToSwap = swapper.getPrice(token, collateralAsset, amountToRepay) * 110 / 100;
+        // we use higher (x2) price impact then required for safety
+        uint minCollateralToSwap =
+            swapper.getPrice(token, collateralAsset, requiredAmount * (100_000 + 2 * priceImpactTolerance) / 100_000); // priceImpactTolerance has its own denominator
 
-        return Math.min(minCollateralToSwap, Math.min(tempCollateralAmount, StrategyLib.balance(collateralAsset)));
+        return Math.min(minCollateralToSwap, StrategyLib.balance(collateralAsset));
     }
 
     //region ------------------------------------- Deposit
     function depositAssets(
+        address platform,
         ILeverageLendingStrategy.LeverageLendingBaseStorage storage $,
         IStrategy.StrategyBaseStorage storage $base,
         uint amount,
@@ -549,6 +558,10 @@ library SiloAdvancedLib {
         }
 
         $base.total += value;
+
+        // ensure that result LTV doesn't exceed max
+        (uint maxLtv,,) = getLtvData(v.lendingVault, $.targetLeveragePercent);
+        _ensureLtvValid($, platform, maxLtv);
     }
 
     function _deposit(
@@ -574,7 +587,9 @@ library SiloAdvancedLib {
 
         return amountToDeposit * priceCtoB * (10 ** IERC20Metadata(v.borrowAsset).decimals())
             * (targetLeverage - INTERNAL_PRECISION) / INTERNAL_PRECISION / 1e18 // priceCtoB has decimals 1e18
-            / (10 ** IERC20Metadata(v.collateralAsset).decimals());
+            // depositParam0 is used to move result leverage to targetValue.
+            // Otherwise result leverage is higher the target value because of swap losses
+            * $.depositParam0 / INTERNAL_PRECISION / (10 ** IERC20Metadata(v.collateralAsset).decimals());
         // not sure that its right way, but its working
         // flashAmounts[0] = flashAmounts[0] * $.depositParam0 / INTERNAL_PRECISION;
     }
@@ -628,6 +643,9 @@ library SiloAdvancedLib {
                 SiloAdvancedLib._deposit($, v, Math.min(state.withdrawParam1 * value / INTERNAL_PRECISION, balance));
             }
         }
+
+        // ensure that result LTV doesn't exceed max
+        _ensureLtvValid($, platform, state.maxLtv);
     }
 
     function withdrawFromLendingVault(
@@ -681,10 +699,6 @@ library SiloAdvancedLib {
                 _withdrawReduceLeverage($, v, state, valueToWithdraw);
             }
         }
-
-        // ensure that result LTV doesn't exceed max
-        (uint ltv,,,,,) = health(platform, $);
-        require(ltv <= state.maxLtv, IControllable.IncorrectLtv(ltv));
     }
 
     function _withdrawReduceLeverage(
@@ -808,6 +822,17 @@ library SiloAdvancedLib {
     //endregion ------------------------------------- Withdraw
 
     //region ------------------------------------- Internal
+
+    /// @notice ensure that result LTV doesn't exceed max
+    function _ensureLtvValid(
+        ILeverageLendingStrategy.LeverageLendingBaseStorage storage $,
+        address platform,
+        uint maxLtv
+    ) internal view {
+        (uint ltv,,,,,) = health(platform, $);
+        require(ltv <= maxLtv, IControllable.IncorrectLtv(ltv));
+    }
+
     function _getFlashLoanAmounts(
         uint borrowAmount,
         address borrowAsset

test/strategies/SiAL.Sonic.sol

@@ -13,7 +13,8 @@ contract SiloAdvancedLeverageStrategyTest is SonicSetup, UniversalTest {
         //vm.rollFork(13119000); // Mar-11-2025 08:29:09 PM +UTC
         // vm.rollFork(18553912); // Apr-01-2025 03:26:51 PM +UTC
         // vm.rollFork(24454255); // May-05-2025 06:57:40 AM +UTC
-        vm.rollFork(25224612); // May-08-2025 10:18:00 AM +UTC
+        // vm.rollFork(25224612); // May-08-2025 10:18:00 AM +UTC
+        vm.rollFork(26428190); // May-13-2025 06:22:27 AM +UTC
         allowZeroApr = true;
         duration1 = 0.1 hours;
         duration2 = 0.1 hours;
@@ -22,9 +23,9 @@ contract SiloAdvancedLeverageStrategyTest is SonicSetup, UniversalTest {
 
     function testSiALSonic() public universalTest {
         //        _addStrategy(SonicConstantsLib.SILO_VAULT_22_wOS, SonicConstantsLib.SILO_VAULT_22_wS, 86_90);
-        //          _addStrategy(SonicConstantsLib.SILO_VAULT_23_wstkscUSD, SonicConstantsLib.SILO_VAULT_23_USDC, 88_00);
-        //         _addStrategy(SonicConstantsLib.SILO_VAULT_26_wstkscETH, SonicConstantsLib.SILO_VAULT_26_wETH, 90_00);
-        //         _addStrategy(SonicConstantsLib.SILO_VAULT_25_wanS, SonicConstantsLib.SILO_VAULT_25_wS, 90_00);
+        //        _addStrategy(SonicConstantsLib.SILO_VAULT_23_wstkscUSD, SonicConstantsLib.SILO_VAULT_23_USDC, 88_00);
+        //                 _addStrategy(SonicConstantsLib.SILO_VAULT_26_wstkscETH, SonicConstantsLib.SILO_VAULT_26_wETH, 90_00);
+        //                 _addStrategy(SonicConstantsLib.SILO_VAULT_25_wanS, SonicConstantsLib.SILO_VAULT_25_wS, 90_00);
         _addStrategy(SonicConstantsLib.SILO_VAULT_46_PT_aUSDC_14AUG, SonicConstantsLib.SILO_VAULT_46_scUSD, 60_00);
         _addStrategy(SonicConstantsLib.SILO_VAULT_40_PT_stS_29MAY, SonicConstantsLib.SILO_VAULT_40_wS, 65_00);
         //        _addStrategy(SonicConstantsLib.SILO_VAULT_37_PT_wstkscUSD_29MAY, SonicConstantsLib.SILO_VAULT_37_frxUSD, 65_00);