Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

/// @notice A library for performing overflow-/underflow-safe math,
/// updated with awesomeness from of DappHub (https://github.com/dapphub/ds-math).
library AuraMath {
    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
        c = a + b;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256 c) {
        c = a - b;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
        c = a * b;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute.
        return (a / 2) + (b / 2) + (((a % 2) + (b % 2)) / 2);
    }

    function to224(uint256 a) internal pure returns (uint224 c) {
        require(a <= type(uint224).max, "AuraMath: uint224 Overflow");
        c = uint224(a);
    }

    function to128(uint256 a) internal pure returns (uint128 c) {
        require(a <= type(uint128).max, "AuraMath: uint128 Overflow");
        c = uint128(a);
    }

    function to112(uint256 a) internal pure returns (uint112 c) {
        require(a <= type(uint112).max, "AuraMath: uint112 Overflow");
        c = uint112(a);
    }

    function to96(uint256 a) internal pure returns (uint96 c) {
        require(a <= type(uint96).max, "AuraMath: uint96 Overflow");
        c = uint96(a);
    }

    function to32(uint256 a) internal pure returns (uint32 c) {
        require(a <= type(uint32).max, "AuraMath: uint32 Overflow");
        c = uint32(a);
    }
}

/// @notice A library for performing overflow-/underflow-safe addition and subtraction on uint32.
library AuraMath32 {
    function sub(uint32 a, uint32 b) internal pure returns (uint32 c) {
        c = a - b;
    }
}

/// @notice A library for performing overflow-/underflow-safe addition and subtraction on uint112.
library AuraMath112 {
    function add(uint112 a, uint112 b) internal pure returns (uint112 c) {
        c = a + b;
    }

    function sub(uint112 a, uint112 b) internal pure returns (uint112 c) {
        c = a - b;
    }
}

/// @notice A library for performing overflow-/underflow-safe addition and subtraction on uint224.
library AuraMath224 {
    function add(uint224 a, uint224 b) internal pure returns (uint224 c) {
        c = a + b;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface IBooster {
    struct FeeDistro {
        address distro;
        address rewards;
        bool active;
    }

    function feeTokens(address _token) external returns (FeeDistro memory);

    function earmarkFees(address _feeToken) external returns (bool);

    struct PoolInfo {
        address lptoken;
        address token;
        address gauge;
        address crvRewards;
        address stash;
        bool shutdown;
    }

    function earmarkRewards(uint256 _pid) external returns (bool);

    function poolLength() external view returns (uint256);

    function lockRewards() external view returns (address);

    function poolInfo(uint256 _pid) external view returns (PoolInfo memory poolInfo);

    function distributeL2Fees(uint256 _amount) external;

    function lockIncentive() external view returns (uint256);

    function stakerIncentive() external view returns (uint256);

    function earmarkIncentive() external view returns (uint256);

    function platformFee() external view returns (uint256);

    function FEE_DENOMINATOR() external view returns (uint256);

    function voteGaugeWeight(address[] calldata _gauge, uint256[] calldata _weight) external returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

import { IERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/utils/SafeERC20.sol";
import { IStashRewardDistro } from "../interfaces/IStashRewardDistro.sol";
import { IVirtualRewards } from "../interfaces/IVirtualRewards.sol";
import { IExtraRewardStash } from "../interfaces/IExtraRewardStash.sol";
import { AuraMath } from "../utils/AuraMath.sol";
import { IBooster } from "../interfaces/IBooster.sol";

interface IBoosterOrBoosterLite is IBooster {
    function earmarkRewards(uint256, address) external;
}

/**
 * @title   StashRewardDistro
 * @author  Aura Finance
 */
contract StashRewardDistro is IStashRewardDistro {
    using AuraMath for uint256;
    using SafeERC20 for IERC20;

    /* -------------------------------------------------------------------
       Storage 
    ------------------------------------------------------------------- */

    // @dev Epoch duration
    uint256 public constant EPOCH_DURATION = 1 weeks;

    // @dev The booster address
    IBoosterOrBoosterLite public immutable booster;

    // @dev Epoch => Pool ID => Token => Amount
    mapping(uint256 => mapping(uint256 => mapping(address => uint256))) public getFunds;

    /* -------------------------------------------------------------------
       Events 
    ------------------------------------------------------------------- */

    event Funded(uint256 epoch, uint256 pid, address token, uint256 amount);
    event Queued(uint256 epoch, uint256 pid, address token, uint256 amount);

    /* -------------------------------------------------------------------
       Constructor 
    ------------------------------------------------------------------- */

    /**
     * @param _booster The booster
     */
    constructor(address _booster) {
        booster = IBoosterOrBoosterLite(_booster);
    }

    /* -------------------------------------------------------------------
       View 
    ------------------------------------------------------------------- */

    /**
     * @dev Get the current epoch
     */
    function getCurrentEpoch() external view returns (uint256) {
        return _getCurrentEpoch();
    }

    /* -------------------------------------------------------------------
       Core
    ------------------------------------------------------------------- */

    /**
     * @dev  Fund a pool for the next epoch. Epochs are 1 week in length and run
     *       Thursday to Thursday
     * @param _pid Pool ID
     * @param _token Token address
     * @param _amount Amount of the token to fund in total
     * @param _periods Number of periods to fund
     *                 _amount is split evenly between the number of periods
     */
    function fundPool(
        uint256 _pid,
        address _token,
        uint256 _amount,
        uint256 _periods
    ) external {
        // Keep 1 wei of the reward token for each period to faciliate
        // processing idle rewards if needed
        uint256 rewardAmount = _amount - _periods;

        // Loop through n periods and assign rewards to each epoch
        // Add 1 to the epoch so it can only be queued for the next epoch which
        // will be the next thursday. The process will be
        // fundPool is called on tuesday and adds rewards to the next epoch which
        // will start on thursday
        uint256 epoch = _getCurrentEpoch().add(1);
        uint256 epochAmount = rewardAmount.div(_periods);
        for (uint256 i = 0; i < _periods; i++) {
            getFunds[epoch][_pid][_token] = getFunds[epoch][_pid][_token].add(epochAmount);
            emit Funded(epoch, _pid, _token, epochAmount);
            epoch++;
        }

        IERC20(_token).safeTransferFrom(msg.sender, address(this), _amount);
    }

    /**
     * @notice Queue the current epoch's rewards to the pid's stash and calls earmark rewards
     * @param _pid  The pool id to queue rewards.
     * @param _token The reward token.
     */
    function queueRewards(uint256 _pid, address _token) external {
        _queueRewards(_getCurrentEpoch(), _pid, _token);
    }

    /**
     * @notice Queue rewards to the pid's stash and calls earmark rewards
     *  It can only queue past or current epoch's rewards
     * @param _pid  The pool id to queue rewards.
     * @param _token The reward token.
     * @param _epoch The epoch to process.
     */
    function queueRewards(
        uint256 _pid,
        address _token,
        uint256 _epoch
    ) external {
        require(_epoch <= _getCurrentEpoch(), "!epoch");
        _queueRewards(_epoch, _pid, _token);
    }

    /**
     * @notice Processes queued rewards in isolation, providing the period has finished.
     *      It sends 1 wei to the stash and call earmark rewards on the booster
     * @param _pid  The pool id to process idle rewards.
     * @param _token The reward token.
     */
    function processIdleRewards(uint256 _pid, address _token) external {
        // Get the stash and the extra rewards contract
        IBoosterOrBoosterLite.PoolInfo memory poolInfo = booster.poolInfo(_pid);
        IExtraRewardStash stash = IExtraRewardStash(poolInfo.stash);
        (, address rewards, ) = stash.tokenInfo(_token);

        // Check that the period finish has passed and there are queued
        // rewards that need processing
        uint256 periodFinish = IVirtualRewards(rewards).periodFinish();
        uint256 queuedRewards = IVirtualRewards(rewards).queuedRewards();
        require(block.timestamp > periodFinish, "!periodFinish");
        require(queuedRewards != 0, "!queueRewards");

        // Transfer 1 wei to the stash and call earmark to force a new
        // queue of rewards to start
        IERC20(_token).safeTransfer(address(stash), 1);
        _earmarkRewards(_pid);
    }

    /* -------------------------------------------------------------------
       Internal 
    ------------------------------------------------------------------- */

    function _queueRewards(
        uint256 _epoch,
        uint256 _pid,
        address _token
    ) internal {
        uint256 amount = getFunds[_epoch][_pid][_token];
        require(amount != 0, "!amount");
        getFunds[_epoch][_pid][_token] = 0;

        IBoosterOrBoosterLite.PoolInfo memory poolInfo = booster.poolInfo(_pid);
        IERC20(_token).safeTransfer(poolInfo.stash, amount);
        emit Queued(_epoch, _pid, _token, amount);
    }

    function _getCurrentEpoch() internal view returns (uint256) {
        return block.timestamp.div(EPOCH_DURATION);
    }

    function _earmarkRewards(uint256 pid) internal virtual {
        booster.earmarkRewards(pid);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface IVirtualRewardFactory {
    function createVirtualReward(
        address,
        address,
        address
    ) external returns (address);
}

interface IVirtualRewards {
    function periodFinish() external view returns (uint256);

    function queuedRewards() external view returns (uint256);

    function queueNewRewards(uint256) external;

    function rewardToken() external view returns (address);

    function getReward() external;
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface IExtraRewardStash {
    function tokenInfo(address)
        external
        view
        returns (
            address,
            address,
            address
        );
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

interface IStashRewardDistro {
    function fundPool(
        uint256 pid,
        address token,
        uint256 amount,
        uint256 period
    ) external;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity ^0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    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));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        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 safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}