// 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 */ contract StrategyEmptyWETH { using SafeERC20 for IERC20; using Address for address; using SafeMath for uint256; address constant public want = address(0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2); // WETH uint public withdrawalFee = 50; uint constant public withdrawalMax = 10000; address public governance; address public controller; address public strategist; constructor(address _controller) public { governance = msg.sender; strategist = msg.sender; controller = _controller; } function setStrategist(address _strategist) external { require(msg.sender == governance, "!governance"); strategist = _strategist; } function setWithdrawalFee(uint _withdrawalFee) external { require(msg.sender == governance, "!governance"); withdrawalFee = _withdrawalFee; } function deposit() public { // empty strategy, does nothing } // 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)); uint _fee = _amount.mul(withdrawalFee).div(withdrawalMax); IERC20(want).safeTransfer(Controller(controller).rewards(), _fee); 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.sub(_fee)); } // Withdraw all funds, normally used when migrating strategies function withdrawAll() external returns (uint balance) { require(msg.sender == controller, "!controller"); 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 balanceOfWant() public view returns (uint) { return IERC20(want).balanceOf(address(this)); } function balanceOf() public view returns (uint) { return balanceOfWant(); } function setGovernance(address _governance) external { require(msg.sender == governance, "!governance"); governance = _governance; } function setController(address _controller) external { require(msg.sender == governance, "!governance"); controller = _controller; } }