// SPDX-License-Identifier: MIT pragma solidity 0.6.12; interface IERC20 { function totalSupply() external view returns (uint256); function balanceOf(address account) external view returns (uint256); function transfer(address recipient, uint256 amount) external returns (bool); function allowance(address owner, address spender) external view returns (uint256); function decimals() external view returns (uint); function approve(address spender, uint256 amount) external returns (bool); function transferFrom(address sender, address recipient, uint256 amount) external returns (bool); event Transfer(address indexed from, address indexed to, uint256 value); event Approval(address indexed owner, address indexed spender, uint256 value); } library SafeMath { function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; require(c >= a, "SafeMath: addition overflow"); return c; } function sub(uint256 a, uint256 b) internal pure returns (uint256) { return sub(a, b, "SafeMath: subtraction overflow"); } function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b <= a, errorMessage); uint256 c = a - b; return c; } function mul(uint256 a, uint256 b) internal pure returns (uint256) { if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b, "SafeMath: multiplication overflow"); return c; } function div(uint256 a, uint256 b) internal pure returns (uint256) { return div(a, b, "SafeMath: division by zero"); } function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { // Solidity only automatically asserts when dividing by 0 require(b > 0, errorMessage); uint256 c = a / b; return c; } function mod(uint256 a, uint256 b) internal pure returns (uint256) { return mod(a, b, "SafeMath: modulo by zero"); } function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b != 0, errorMessage); return a % b; } } library Address { function isContract(address account) internal view returns (bool) { bytes32 codehash; bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; // solhint-disable-next-line no-inline-assembly assembly { codehash := extcodehash(account) } return (codehash != 0x0 && codehash != accountHash); } function toPayable(address account) internal pure returns (address payable) { return address(uint160(account)); } function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); // solhint-disable-next-line avoid-call-value (bool success, ) = recipient.call.value(amount)(""); require(success, "Address: unable to send value, recipient may have reverted"); } } library SafeERC20 { using SafeMath for uint256; using Address for address; function safeTransfer(IERC20 token, address to, uint256 value) internal { callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value)); } function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal { callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value)); } function safeApprove(IERC20 token, address spender, uint256 value) internal { require((value == 0) || (token.allowance(address(this), spender) == 0), "SafeERC20: approve from non-zero to non-zero allowance" ); callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value)); } function callOptionalReturn(IERC20 token, bytes memory data) private { require(address(token).isContract(), "SafeERC20: call to non-contract"); // solhint-disable-next-line avoid-low-level-calls (bool success, bytes memory returndata) = address(token).call(data); require(success, "SafeERC20: low-level call failed"); if (returndata.length > 0) { // Return data is optional // solhint-disable-next-line max-line-length require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed"); } } } interface Controller { function vaults(address) external view returns (address); function rewards() external view returns (address); } /* A strategy must implement the following calls; - deposit() - withdraw(address) - Controller role - withdraw should return to Controller - withdraw(uint) - Controller | Vault role - withdraw should always return to vault - withdrawAll() - Controller | Vault role - withdraw should always return to vault - balanceOf() Where possible, strategies must remain as immutable as possible, instead of updating variables, we update the contract by linking it in the controller */ interface yERC20 { function deposit(uint) external; function withdraw(uint) external; function getPricePerFullShare() external view returns (uint); } interface ICurveFi { function get_virtual_price() external view returns (uint); function add_liquidity( uint256[4] calldata amounts, uint256 min_mint_amount ) external; function remove_liquidity_imbalance( uint256[4] calldata amounts, uint256 max_burn_amount ) external; function remove_liquidity( uint256 _amount, uint256[4] calldata amounts ) external; function exchange( int128 from, int128 to, uint256 _from_amount, uint256 _min_to_amount ) external; } contract StrategyTUSDCurve { using SafeERC20 for IERC20; using Address for address; using SafeMath for uint256; address constant public want = address(0x0000000000085d4780B73119b644AE5ecd22b376); address constant public y = address(0x73a052500105205d34Daf004eAb301916DA8190f); address constant public ycrv = address(0xdF5e0e81Dff6FAF3A7e52BA697820c5e32D806A8); address constant public yycrv = address(0x5dbcF33D8c2E976c6b560249878e6F1491Bca25c); address constant public curve = address(0x45F783CCE6B7FF23B2ab2D70e416cdb7D6055f51); address constant public dai = address(0x6B175474E89094C44Da98b954EedeAC495271d0F); address constant public ydai = address(0x16de59092dAE5CcF4A1E6439D611fd0653f0Bd01); address constant public usdc = address(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48); address constant public yusdc = address(0xd6aD7a6750A7593E092a9B218d66C0A814a3436e); address constant public usdt = address(0xdAC17F958D2ee523a2206206994597C13D831ec7); address constant public yusdt = address(0x83f798e925BcD4017Eb265844FDDAbb448f1707D); address constant public tusd = address(0x0000000000085d4780B73119b644AE5ecd22b376); address constant public ytusd = address(0x73a052500105205d34Daf004eAb301916DA8190f); address public governance; address public controller; constructor(address _controller) public { governance = msg.sender; controller = _controller; } function getName() external pure returns (string memory) { return "StrategyTUSDCurve"; } function deposit() public { uint _want = IERC20(want).balanceOf(address(this)); if (_want > 0) { IERC20(want).safeApprove(y, 0); IERC20(want).safeApprove(y, _want); yERC20(y).deposit(_want); } uint _y = IERC20(y).balanceOf(address(this)); if (_y > 0) { IERC20(y).safeApprove(curve, 0); IERC20(y).safeApprove(curve, _y); ICurveFi(curve).add_liquidity([0,0,0,_y],0); } uint _ycrv = IERC20(ycrv).balanceOf(address(this)); if (_ycrv > 0) { IERC20(ycrv).safeApprove(yycrv, 0); IERC20(ycrv).safeApprove(yycrv, _ycrv); yERC20(yycrv).deposit(_ycrv); } } // Controller only function for creating additional rewards from dust function withdraw(IERC20 _asset) external returns (uint balance) { require(msg.sender == controller, "!controller"); balance = _asset.balanceOf(address(this)); _asset.safeTransfer(controller, balance); } // Withdraw partial funds, normally used with a vault withdrawal function withdraw(uint _amount) external { require(msg.sender == controller, "!controller"); uint _balance = IERC20(want).balanceOf(address(this)); if (_balance < _amount) { _amount = _withdrawSome(_amount.sub(_balance)); _amount = _amount.add(_balance); } address _vault = Controller(controller).vaults(address(want)); require(_vault != address(0), "!vault"); // additional protection so we don't burn the funds IERC20(want).safeTransfer(_vault, _amount); } // Withdraw all funds, normally used when migrating strategies function withdrawAll() external returns (uint balance) { require(msg.sender == controller, "!controller"); _withdrawAll(); balance = IERC20(want).balanceOf(address(this)); address _vault = Controller(controller).vaults(address(want)); require(_vault != address(0), "!vault"); // additional protection so we don't burn the funds IERC20(want).safeTransfer(_vault, balance); } function withdrawTUSD(uint256 _amount) internal returns (uint) { IERC20(ycrv).safeApprove(curve, 0); IERC20(ycrv).safeApprove(curve, _amount); ICurveFi(curve).remove_liquidity(_amount, [uint256(0),0,0,0]); uint256 _ydai = IERC20(ydai).balanceOf(address(this)); uint256 _yusdc = IERC20(yusdc).balanceOf(address(this)); uint256 _yusdt = IERC20(yusdt).balanceOf(address(this)); if (_ydai > 0) { IERC20(ydai).safeApprove(curve, 0); IERC20(ydai).safeApprove(curve, _ydai); ICurveFi(curve).exchange(0, 3, _ydai, 0); } if (_yusdc > 0) { IERC20(yusdc).safeApprove(curve, 0); IERC20(yusdc).safeApprove(curve, _yusdc); ICurveFi(curve).exchange(1, 3, _yusdc, 0); } if (_yusdt > 0) { IERC20(yusdt).safeApprove(curve, 0); IERC20(yusdt).safeApprove(curve, _yusdt); ICurveFi(curve).exchange(2, 3, _yusdt, 0); } uint _before = IERC20(want).balanceOf(address(this)); yERC20(ytusd).withdraw(IERC20(ytusd).balanceOf(address(this))); uint _after = IERC20(want).balanceOf(address(this)); return _after.sub(_before); } function _withdrawAll() internal { uint _yycrv = IERC20(yycrv).balanceOf(address(this)); if (_yycrv > 0) { yERC20(yycrv).withdraw(_yycrv); withdrawTUSD(IERC20(ycrv).balanceOf(address(this))); } } function _withdrawSome(uint256 _amount) internal returns (uint) { // calculate amount of ycrv to withdraw for amount of _want_ uint _ycrv = _amount.mul(1e18).div(ICurveFi(curve).get_virtual_price()); // calculate amount of yycrv to withdraw for amount of _ycrv_ uint _yycrv = _ycrv.mul(1e18).div(yERC20(yycrv).getPricePerFullShare()); uint _before = IERC20(ycrv).balanceOf(address(this)); yERC20(yycrv).withdraw(_yycrv); uint _after = IERC20(ycrv).balanceOf(address(this)); return withdrawTUSD(_after.sub(_before)); } function balanceOfWant() public view returns (uint) { return IERC20(want).balanceOf(address(this)); } function balanceOfYYCRV() public view returns (uint) { return IERC20(yycrv).balanceOf(address(this)); } function balanceOfYYCRVinYCRV() public view returns (uint) { return balanceOfYYCRV().mul(yERC20(yycrv).getPricePerFullShare()).div(1e18); } function balanceOfYYCRVinyTUSD() public view returns (uint) { return balanceOfYYCRVinYCRV().mul(ICurveFi(curve).get_virtual_price()).div(1e18); } function balanceOfYCRV() public view returns (uint) { return IERC20(ycrv).balanceOf(address(this)); } function balanceOfYCRVyTUSD() public view returns (uint) { return balanceOfYCRV().mul(ICurveFi(curve).get_virtual_price()).div(1e18); } function balanceOf() public view returns (uint) { return balanceOfWant() .add(balanceOfYYCRVinyTUSD()); } function setGovernance(address _governance) external { require(msg.sender == governance, "!governance"); governance = _governance; } function setController(address _controller) external { require(msg.sender == governance, "!governance"); controller = _controller; } }