Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: MIT

pragma solidity 0.8.20;

import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

abstract contract ReentrancyGuard {
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
       _status = _NOT_ENTERED;
    }
	
    modifier nonReentrant() {
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        _status = _ENTERED;

        _;
		
        _status = _NOT_ENTERED;
    }
}

contract BubsyStaking is Ownable, ReentrancyGuard {
    using SafeERC20 for IERC20;
	
    address public BUBSY;
	uint256 public precisionFactor;
	uint256 public undistributedReward;
	
	bool public contractStatus;
	bool public rewardStatus;
	
	uint256[3] public poolDuration;
	uint256[3] public poolMultiplier;
	uint256[3] public BUBSYStaked;
	uint256[3] public minStaking;
	uint256[3] public rewardPerShare;
	uint256[3] public rewardDistributedPerPool;
	
	struct StakingInfo {
	  uint256 stakedBUBSY; 
	  uint256 startTime;
	  uint256 endTime;
	  bool unstaked;
	  uint256 pool;
	  uint256 rewardClaimed;
	  uint256 claimedETH;
	  uint256 rewardUnclaimed;
    }
	
	mapping(address => mapping(uint256 => StakingInfo)) public mapStakingInfo;
	mapping(address => uint256) public stakingCount;
	mapping(address => bool) public isWhitelistForSendFund;
	
	event Staked(address staker, uint256 amount);
	event Unstaked(address staker, uint256 amount, uint256 reward);
	event PoolUpdated(uint256 amount);
	event RewardClaimed(address staker, uint256 amount);
	event ContractStatusUpdated(bool status);
	event RewardStatusUpdated(bool status);
	event PoolDurationUpdated(uint256 pool1, uint256 pool2, uint256 pool3);
	event PoolMultiplierUpdated(uint256 pool1Multiplier, uint256 pool2Multiplier, uint256 pool3Multiplier);
	event WhitelistStatusUpdated(address wallet, bool status);
	event ETHRescueFromContract(address receiver, uint256 amount);
	
    constructor(address _owner) {
	   require(_owner != address(0), "Owner:: zero address");
	   
	   minStaking = [1 * 10**18, 1 * 10**18, 1 * 10**18];
	   poolDuration = [15 days, 90 days, 365 days];
	   poolMultiplier = [100, 125, 200];
	   
	   BUBSY = address(0xD699B83e43415B774B6ed4ce9999680F049aF2ab);
       precisionFactor = 1 * 10**18;
	   _transferOwnership(address(_owner));
    }
	
	receive() external payable {}
	
	function updateContractStatus(bool status) external onlyOwner {
	    require(contractStatus != status, "Same status already active");
		
		contractStatus = status;
		emit ContractStatusUpdated(status);
  	}
	
	function updateRewardStatus(bool status) external onlyOwner {
	    require(rewardStatus != status, "Same status already active");
		
		rewardStatus = status;
		if(rewardStatus && undistributedReward > 0)
		{
		   _distributeReward(undistributedReward);
		   undistributedReward = 0;
		}
		emit RewardStatusUpdated(status);
  	}
	
	function updatePoolDuration(uint256[3] calldata newPoolDuration) external onlyOwner {
	    require(newPoolDuration[0] > 0 && newPoolDuration[1] > 0 && newPoolDuration[2] > 0, "Staking duration is not correct");
		
		poolDuration[0] = newPoolDuration[0];
		poolDuration[1] = newPoolDuration[1];
		poolDuration[2] = newPoolDuration[2];
        emit PoolDurationUpdated(newPoolDuration[0], newPoolDuration[1], newPoolDuration[2]);
    }
	
	function updatePoolMultiplier(uint256[3] calldata newMultiplier) external onlyOwner {
	    require(newMultiplier[0] > 0 && newMultiplier[1] > 0 && newMultiplier[2] > 0, "Pool multiplier amount is not correct");
		
		poolMultiplier[0] = newMultiplier[0];
		poolMultiplier[1] = newMultiplier[1];
		poolMultiplier[2] = newMultiplier[2];
        emit PoolMultiplierUpdated(newMultiplier[0], newMultiplier[1], newMultiplier[2]);
    }
	
	function whitelistFundWallet(address wallet, bool status) external onlyOwner {
	   require(address(wallet) != address(0), "Zero address");
	   require(isWhitelistForSendFund[address(wallet)] != status, "Wallet is already the value of 'status'");
	   
	   isWhitelistForSendFund[address(wallet)] = status;
	   emit WhitelistStatusUpdated(address(wallet), status);
    }
	
	function rescueETH(address receiver, uint256 amount) external onlyOwner {
	   require(address(receiver) != address(0), "Zero address");
	   require(address(this).balance >= amount, "Insufficient ETH balance in contract");
	   
	   payable(address(receiver)).transfer(amount);
	   emit ETHRescueFromContract(address(receiver), amount);
    }
	
	function stake(uint256 amount, uint256 pool) external {
	    require(contractStatus, "Contract is not enabled");
		require(IERC20(BUBSY).balanceOf(address(msg.sender)) >= amount, "Balance not available for staking");
		require(poolDuration.length > pool, "Staking pool is not correct");
		require(amount >= minStaking[pool], "Stake amount is less than required amount");
		
		uint256 count = stakingCount[address(msg.sender)];
		
		IERC20(BUBSY).safeTransferFrom(address(msg.sender), address(this), amount);
		BUBSYStaked[pool] += amount;
		stakingCount[address(msg.sender)] += 1;
		
		mapStakingInfo[address(msg.sender)][count].stakedBUBSY = amount;
		mapStakingInfo[address(msg.sender)][count].startTime = block.timestamp;
		mapStakingInfo[address(msg.sender)][count].endTime = block.timestamp + poolDuration[pool];
		mapStakingInfo[address(msg.sender)][count].pool = pool;
		mapStakingInfo[address(msg.sender)][count].rewardClaimed = (amount * rewardPerShare[pool]) / precisionFactor;
        emit Staked(address(msg.sender), amount);
    }
	
	function unstake(address staker, uint256 count) external onlyOwner nonReentrant {
		require(mapStakingInfo[address(staker)][count].unstaked == false, "Staking already unstaked");
		require(stakingCount[address(staker)] > count, "Staking not found");
		
        uint256 pending = pendingReward(address(msg.sender), count);
		uint256 amount = mapStakingInfo[address(msg.sender)][count].stakedBUBSY;
		uint256 pool = mapStakingInfo[address(msg.sender)][count].pool;
		
		BUBSYStaked[pool] -= amount; 
		mapStakingInfo[address(msg.sender)][count].unstaked = true;
		mapStakingInfo[address(msg.sender)][count].rewardUnclaimed = pending;
		
		IERC20(BUBSY).safeTransfer(address(msg.sender), amount);
		emit Unstaked(address(msg.sender), amount, pending);
    }
	
	function unstake(uint256 count) external nonReentrant {
	    require(contractStatus, "Contract is not enabled");
		require(mapStakingInfo[address(msg.sender)][count].unstaked == false, "Staking already unstaked");
		require(mapStakingInfo[address(msg.sender)][count].endTime <= block.timestamp, "Staking time is not over");
		require(stakingCount[address(msg.sender)] > count, "Staking not found");
		
        uint256 pending = pendingReward(address(msg.sender), count);
		uint256 amount = mapStakingInfo[address(msg.sender)][count].stakedBUBSY;
		uint256 pool = mapStakingInfo[address(msg.sender)][count].pool;
		
		BUBSYStaked[pool] -= amount; 
		mapStakingInfo[address(msg.sender)][count].unstaked = true;
		
		if(pending > 0 && address(this).balance >= pending)
		{
		   payable(address(msg.sender)).transfer(pending);
		   mapStakingInfo[address(msg.sender)][count].claimedETH += pending;
		}
		IERC20(BUBSY).safeTransfer(address(msg.sender), amount);
		emit Unstaked(address(msg.sender), amount, pending);
    }
	
	function claimReward(uint256 count) external nonReentrant{
	    require(stakingCount[address(msg.sender)] > count, "Staking not found");
		require(contractStatus, "Contract is not enabled");
		
	    uint256 pending = pendingReward(address(msg.sender), count);
		if(pending > 0 && address(this).balance >= pending) 
		{
			payable(address(msg.sender)).transfer(pending);
			
			uint256 pool = mapStakingInfo[address(msg.sender)][count].pool;
		    uint256 amount = mapStakingInfo[address(msg.sender)][count].stakedBUBSY;
			mapStakingInfo[address(msg.sender)][count].rewardClaimed = (amount * rewardPerShare[pool]) / precisionFactor;
			mapStakingInfo[address(msg.sender)][count].claimedETH += pending;
			emit RewardClaimed(address(msg.sender), pending);
		}
    }
	
	function pendingReward(address staker, uint256 count) public view returns (uint256) {
	
	   if(mapStakingInfo[address(staker)][count].stakedBUBSY > 0 && !mapStakingInfo[address(staker)][count].unstaked && stakingCount[address(staker)] > count)
	   {
		   uint256 pool = mapStakingInfo[address(staker)][count].pool;
		   uint256 amount = mapStakingInfo[address(staker)][count].stakedBUBSY;
		   uint256 claimed = mapStakingInfo[address(staker)][count].rewardClaimed;
		   
		   uint256 pending = ((amount * rewardPerShare[pool]) / precisionFactor) - (claimed);
		   return pending;
       } 
	   else 
	   {
		   return 0;
	   }
    }
	
	function updatePool() external payable nonReentrant {
	   require(isWhitelistForSendFund[address(msg.sender)], "Sender is not whitelisted for add fund");
	   
	   if(rewardStatus)
	   {
	       _distributeReward(msg.value);
	   }
	   else
	   {
	       undistributedReward += msg.value;
	   }
	   emit PoolUpdated(msg.value);
    }
	
	function _distributeReward(uint256 amount) internal {	
	   
	   uint256 pool0StakedBUBSY = ((BUBSYStaked[0] * poolMultiplier[0]) / 100);
	   uint256 pool1StakedBUBSY = ((BUBSYStaked[1] * poolMultiplier[1]) / 100);
	   uint256 pool2StakedBUBSY = ((BUBSYStaked[2] * poolMultiplier[2]) / 100);
	   uint256 totalStakedBUBSY = (pool0StakedBUBSY + pool1StakedBUBSY + pool2StakedBUBSY);
	   
	   if(totalStakedBUBSY > 0)
	   {
	      uint256 pool0Share = ((amount * pool0StakedBUBSY) / totalStakedBUBSY);
		  uint256 pool1Share = ((amount * pool1StakedBUBSY) / totalStakedBUBSY);
		  uint256 pool2Share = amount - pool0Share - pool1Share;
		  
		  rewardPerShare[0] += ((pool0Share * precisionFactor) / BUBSYStaked[0]);
		  rewardPerShare[1] += ((pool1Share * precisionFactor) / BUBSYStaked[1]);
		  rewardPerShare[2] += ((pool2Share * precisionFactor) / BUBSYStaked[2]);
		  
		  rewardDistributedPerPool[0] += pool0Share;
		  rewardDistributedPerPool[1] += pool1Share;
		  rewardDistributedPerPool[2] += pool2Share;
	   }
	   else
	   {
	      undistributedReward += amount;
	   }
	}
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @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
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 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
                /// @solidity memory-safe-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 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);

    /**
     * @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 `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, 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 `from` to `to` 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 from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.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));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @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");
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}