// File: contracts/lib/IERC20.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.7.1;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: contracts/RedeemRSFI.sol


pragma solidity ^0.7.1;


contract RedeemRSFI {
  IERC20 public constant SFI = IERC20(address(0xb753428af26E81097e7fD17f40c88aaA3E04902c));
  IERC20 public constant rSFI = IERC20(address(0x5dB451f9913C57dC103c6B9dF46FF9be42C28510));
  address public constant burn_address = address(0x000000000000000000000000000000000000dEaD);
  address public constant multisig = address(0xAA394e08C74e2B2f76fF000AdEB25f20423CFe2A);

  event RedeemSFI(address addr, uint256 amount);
  function redeem_SFI(uint256 amount) external {
    require(amount != 0, "can't redeem 0");
    require(rSFI.balanceOf(msg.sender) >= amount, "insufficient rSFI tokens to redeem SFI");
    rSFI.transferFrom(msg.sender, address(burn_address), amount);
    SFI.transfer(msg.sender, amount);
    emit RedeemSFI(msg.sender, amount);
  }

  event ErcSwept(address who, address to, address token, uint256 amount);
  function erc_sweep(address _token, address _to) public {
    require(msg.sender == multisig, "must be multisig");

    IERC20 tkn = IERC20(_token);
    uint256 tBal = tkn.balanceOf(address(this));
    tkn.transfer(_to, tBal);

    emit ErcSwept(msg.sender, _to, _token, tBal);
  }
}