pragma solidity ^0.6.0;

interface IERC20 {
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
}

/**
 * @dev A token holder contract that will allow a beneficiary to extract the tokens after a given release time.
 *
 * Useful for simple vesting schedules like "advisors get all of their tokens after 2 years".
 */
contract TokenTimelock {
    // ERC20 basic token contract being held
    IERC20 public token;

    // beneficiary of tokens after they are released
    address public beneficiary;

    // timestamp when token release is enabled
    uint256 public releaseTime;

    constructor () public {
        token = IERC20(0x309013d55fB0E8C17363bcC79F25d92f711A5802); // SBTC
        beneficiary = 0x579Ab04AC79849576e7a49202D925e3335049162; // SBTC Foundation
        releaseTime = block.timestamp + 730 days;
    }

    /**
     * @notice Transfers tokens held by timelock to beneficiary.
     */
    function release() public virtual {
        require(block.timestamp >= releaseTime, "TokenTimelock: current time is before release time");

        uint256 amount = token.balanceOf(address(this));
        require(amount > 0, "TokenTimelock: no tokens to release");

        token.transfer(beneficiary, amount);
    }
}