# BaseYearnV3Strategy ## Overview The BaseYearnV3Strategy contract is the base implementation for strategies interacting with Yearn v3 vaults in the MaxAPY ecosystem. It handles deposits into Yearn vaults, manages share calculations, and provides core functionality for vault interactions. ## Constants No internal constants defined in this contract. ## Errors ```solidity error NotEnoughFundsToInvest(); // Insufficient funds for investment error InvalidZeroAddress(); // Zero address provided ``` ## Events ```solidity event Invested(address indexed strategy, uint256 amountInvested); event Divested(address indexed strategy, uint256 requestedShares, uint256 amountDivested); event MaxSingleTradeUpdated(uint256 maxSingleTrade); event MinSingleTradeUpdated(uint256 minSingleTrade); ``` ## State Variables ```solidity IYVaultV3 public yVault; // Yearn vault reference uint256 public maxSingleTrade; // Maximum trade size uint256 public minSingleTrade; // Minimum trade size ``` ## Functions ### Initialization Functions #### constructor ```solidity constructor() initializer ``` Empty constructor marked as initializer. #### initialize ```solidity function initialize( IMaxApyVault _vault, address[] calldata _keepers, bytes32 _strategyName, address _strategist, IYVaultV3 _yVault ) public virtual initializer ``` Initializes the strategy with Yearn components. Parameters: * `_vault`: MaxApy vault address * `_keepers`: Array of keeper addresses * `_strategyName`: Name of the strategy * `_strategist`: Strategist address * `_yVault`: Yearn vault address ### Core Functions #### liquidateExact ```solidity function liquidateExact(uint256 amountNeeded) external returns (uint256 loss) ``` Withdraws exactly amountNeeded to vault. Can only be called by vault. #### Parameters: * `amountNeeded`: Amount of underlying asset to withdraw #### Returns: * `loss`: Amount of loss realized during withdrawal ### Configuration Functions #### setMaxSingleTrade ```solidity function setMaxSingleTrade(uint256 _maxSingleTrade) external checkRoles(ADMIN_ROLE) ``` Sets the maximum amount allowed for a single trade. Parameters: * `_maxSingleTrade`: New maximum trade size #### setMinSingleTrade ```solidity function setMinSingleTrade(uint256 _minSingleTrade) external checkRoles(ADMIN_ROLE) ``` Sets the minimum amount required for a single trade. Parameters: * `_minSingleTrade`: New minimum trade size ### View Functions #### previewLiquidate ```solidity function previewLiquidate(uint256 requestedAmount) public view virtual override returns (uint256 liquidatedAmount) ``` Simulates withdrawal including potential losses. Parameters: * `requestedAmount`: Amount requested to withdraw Returns: * `liquidatedAmount`: Expected output amount after losses #### previewLiquidateExact ```solidity function previewLiquidateExact(uint256 liquidatedAmount) public view virtual override returns (uint256 requestedAmount) ``` Calculates input amount needed for exact output. Parameters: * `liquidatedAmount`: Desired output amount Returns: * `requestedAmount`: Required input amount #### maxLiquidate ```solidity function maxLiquidate() public view virtual override returns (uint256) ``` Returns maximum withdrawable amount considering potential losses. Returns: * Maximum amount that can be withdrawn #### maxLiquidateExact ```solidity function maxLiquidateExact() public view virtual override returns (uint256) ``` Returns maximum withdrawable amount before considering losses. Returns: * Maximum amount that can be withdrawn before losses ### Internal Functions #### \_prepareReturn ```solidity function _prepareReturn( uint256 debtOutstanding, uint256 minExpectedBalance ) internal virtual override returns (uint256 unrealizedProfit, uint256 loss, uint256 debtPayment) ``` Prepares strategy returns and handles debt repayment. Parameters: * `debtOutstanding`: Amount of debt that needs to be repaid * `minExpectedBalance`: Minimum balance expected after operation Returns: * `unrealizedProfit`: Amount of profit generated * `loss`: Amount of losses incurred * `debtPayment`: Amount of debt repaid #### \_adjustPosition ```solidity function _adjustPosition(uint256, uint256 minOutputAfterInvestment) internal virtual override ``` Adjusts strategy positions based on available capital. Parameters: * `minOutputAfterInvestment`: Minimum expected output after investment #### \_invest ```solidity function _invest( uint256 amount, uint256 minOutputAfterInvestment ) internal virtual returns (uint256 depositedAmount) ``` Deposits assets into Yearn vault. Parameters: * `amount`: Amount to invest * `minOutputAfterInvestment`: Minimum expected shares Returns: * `depositedAmount`: Amount of tokens successfully invested #### \_divest ```solidity function _divest(uint256 shares) internal virtual returns (uint256 withdrawn) ``` Withdraws assets from Yearn vault. Parameters: * `shares`: Amount of shares to withdraw Returns: * `withdrawn`: Amount of assets received #### \_liquidatePosition ```solidity function _liquidatePosition(uint256 amountNeeded) internal virtual override returns (uint256 liquidatedAmount, uint256 loss) ``` Liquidates position up to requested amount. Parameters: * `amountNeeded`: Amount needed to liquidate Returns: * `liquidatedAmount`: Amount actually liquidated * `loss`: Amount of losses incurred #### \_liquidateAllPositions ```solidity function _liquidateAllPositions() internal virtual override returns (uint256 amountFreed) ``` Liquidates all positions, used during emergency exit. Returns: * `amountFreed`: Total amount freed from positions ### Internal View Functions #### \_shareValue ```solidity function _shareValue(uint256 shares) internal view virtual returns (uint256 _assets) ``` Calculates the underlying value of shares. Parameters: * `shares`: Amount of shares to value Returns: * `_assets`: Value in underlying asset terms #### \_sharesForAmount ```solidity function _sharesForAmount(uint256 amount) internal view virtual returns (uint256 _shares) ``` Calculates shares needed for a given amount of assets. Parameters: * `amount`: Amount of assets Returns: * `_shares`: Required number of shares #### \_shareBalance ```solidity function _shareBalance() internal view virtual returns (uint256 _balance) ``` Returns the strategy's current Yearn vault share balance. Returns: * `_balance`: Current share balance #### \_estimatedTotalAssets ```solidity function _estimatedTotalAssets() internal view virtual override returns (uint256) ``` Calculates total value of all assets under management. Returns: * Total value of assets in underlying terms #### \_simulateHarvest ```solidity function _simulateHarvest() public override ``` Simulates a harvest operation and reverts with simulation data. Used for testing and verification.