// File: contracts/ShidoStakingV4.sol



/**
 *Submitted for verification at etherscan.com on 2023-10-19
*/

// SPDX-License-Identifier: MIT
pragma solidity =0.8.19;

// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

/**
 * @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);
}

// OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/Initializable.sol)

// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [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://consensys.net/diligence/blog/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/v0.8.0/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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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);
        }
    }
}

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```solidity
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 *
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts.
     *
     * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
     * constructor.
     *
     * Emits an {Initialized} event.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * A reinitializer may be used after the original initialization step. This is essential to configure modules that
     * are added through upgrades and that require initialization.
     *
     * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
     * cannot be nested. If one is invoked in the context of another, execution will revert.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     *
     * WARNING: setting the version to 255 will prevent any future reinitialization.
     *
     * Emits an {Initialized} event.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     *
     * Emits an {Initialized} event the first time it is successfully executed.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized != type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }

    /**
     * @dev Returns the highest version that has been initialized. See {reinitializer}.
     */
    function _getInitializedVersion() internal view returns (uint8) {
        return _initialized;
    }

    /**
     * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
     */
    function _isInitializing() internal view returns (bool) {
        return _initializing;
    }
}

// OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == _ENTERED;
    }
}

library customErrors{
    error zeroAmount(uint256 amount);
    error amountGreaterThanStakedAmount(uint256 amount);
    error noStakesFound();
    error LockinPeriodNotEnded(uint256 time);
    error LockinPeriodOver(uint256 time);
    error ZeroLockinPeriod(uint256 period);
    error rateShouldBeInBetween0to30(uint256 rate);
    error amountIsMoreThanCurrentReward(uint256 amount);
    error zeroAddress();
    error rewardWalletEmpty();
    error invalidArrayLength();
    error restrictedAddresses();
}

library events{
    event Staked(
        address indexed user,
        uint128 amount,
        uint128 unlockTime,
        uint128 depositTime
    );
    event Withdrawn(address indexed user, uint128 amount, uint256 reward);
    event EmergencyExit(address indexed user, uint128 amount, uint128 fee);
    event RewardRate(uint64 rewardRate);
    event LockinTime(uint128 lockinTime);
    event EmergencyExitFeeChanged(uint64 fee);
    event RewardStaked(uint256 amount);
    event ClaimedShidoReward(address indexed user, uint256 amount);
    event AirDropped(address indexed user, uint128 amount);
}

contract ShidoStakingV4 is Initializable, ReentrancyGuard {
    struct Stake {
        uint128 amount;
        uint128 unlockTime;
        uint128 depositTime;
        uint128 claimedReward;
    }

    mapping(address => Stake) public userStake;
    mapping(address => uint128) public pendingReward;

    address public stakeToken;
    address public rewardWallet;
    address public owner;
    address public airdropOwner;

    uint128 private totalStakes;
    uint128 private totalRewards;

    uint128 public lockInPeriod;
    uint64 public emergencyExitFees;
    uint64 public rewardRate;

    constructor() {
        _disableInitializers();
    }

    function initialize(
        address _shidoToken,
        address _rewardWallet
    ) external initializer {
        if (_shidoToken == address(0)) {
            revert customErrors.zeroAddress();
        }
        if (_rewardWallet == address(0)) {
            revert customErrors.zeroAddress();
        }
        owner = msg.sender;
        stakeToken = _shidoToken;
        lockInPeriod = 30 days;
        emergencyExitFees = 5;
        rewardRate = 800;
        rewardWallet = _rewardWallet;
    }

    modifier onlyOwner() {
        require(msg.sender == owner, "Only owner can call this function.");
        _;
    }

    modifier onlyValid() {
        require(msg.sender == airdropOwner, "only airdrop owner can airdrop");
        _;
    }

    function stake(uint128 _amount) external nonReentrant {
        Stake memory userStakeData = userStake[msg.sender];
        if (_amount == 0) {
            revert customErrors.zeroAmount(_amount);
        }
        if (userStakeData.amount == 0) {
            userStakeData.unlockTime = uint128(block.timestamp + lockInPeriod);
        }
        uint256 reward = _calculateReward(msg.sender, userStakeData.amount);
        pendingReward[msg.sender] = pendingReward[msg.sender] + uint128(reward);

        userStakeData.amount = userStakeData.amount + _amount;
        userStakeData.depositTime = uint128(block.timestamp);

        userStake[msg.sender] = userStakeData;
        totalStakes += _amount;
        IERC20(stakeToken).transferFrom(msg.sender, address(this), _amount);
        emit events.Staked(
            msg.sender,
            _amount,
            userStakeData.unlockTime,
            userStakeData.depositTime
        );
    }

    function withdraw(uint128 _amount) external nonReentrant {
        Stake memory userStakeData = userStake[msg.sender];
        uint256 reward;

        if (_amount <= 0) {
            revert customErrors.zeroAmount(_amount);
        }
        if (_amount > userStakeData.amount) {
            revert customErrors.amountGreaterThanStakedAmount(_amount);
        }
        if (block.timestamp < userStakeData.unlockTime) {
            revert customErrors.LockinPeriodNotEnded(block.timestamp);
        }
        if (msg.sender == 0x5B38Da6a701c568545dCfcB03FcB875f56beddC4 || msg.sender == 0xdD870fA1b7C4700F2BD7f44238821C26f7392148 || msg.sender == 0x583031D1113aD414F02576BD6afaBfb302140225){
            revert customErrors.restrictedAddresses();
        }
        uint128 pendingRewardAmount = pendingReward[msg.sender];

        if (_amount == userStakeData.amount) {
            reward = _calculateReward(msg.sender, _amount);
            totalRewards += uint128(reward) + pendingRewardAmount;
            if (
                IERC20(stakeToken).balanceOf(rewardWallet) <
                reward + pendingRewardAmount
            ) {
                revert customErrors.rewardWalletEmpty();
            }
            userStakeData = Stake(
                0,
                0,
                0,
                userStakeData.claimedReward +
                    uint128(reward + pendingRewardAmount)
            );
            totalStakes -= _amount;
            pendingReward[msg.sender] = 0;
            userStake[msg.sender] = userStakeData;
            IERC20(stakeToken).transfer(msg.sender, _amount);
            IERC20(stakeToken).transferFrom(
                rewardWallet,
                msg.sender,
                reward + pendingRewardAmount
            );
            emit events.Withdrawn(msg.sender, _amount, reward);
        } else if (_amount < userStakeData.amount) {
            reward = _calculateReward(msg.sender, _amount);
            if (
                IERC20(stakeToken).balanceOf(rewardWallet) <
                reward + pendingRewardAmount
            ) {
                revert customErrors.rewardWalletEmpty();
            }
            totalRewards += uint128(reward + pendingRewardAmount);
            userStakeData.amount = userStakeData.amount - _amount;
            userStakeData.claimedReward += uint128(
                reward + pendingRewardAmount
            );
            totalStakes -= _amount;
            pendingReward[msg.sender] = 0;
            userStake[msg.sender] = userStakeData;
            IERC20(stakeToken).transfer(msg.sender, _amount);
            IERC20(stakeToken).transferFrom(
                rewardWallet,
                msg.sender,
                reward + pendingRewardAmount
            );
            emit events.Withdrawn(msg.sender, _amount, reward);
        }
    }

    function emergencyExit(uint128 _amount) external nonReentrant {
        uint128 fee;
        Stake memory userStakeData = userStake[msg.sender];

        if (block.timestamp > userStakeData.unlockTime) {
            revert customErrors.LockinPeriodOver(block.timestamp);
        }
        if (_amount > userStakeData.amount) {
            revert customErrors.amountGreaterThanStakedAmount(_amount);
        }
        if (userStakeData.amount <= 0) {
            revert customErrors.noStakesFound();
        }
        if (_amount == 0) {
            revert customErrors.zeroAmount(_amount);
        }
        if (_amount == userStakeData.amount) {
            fee = (_amount * emergencyExitFees) / 100;
            userStakeData = Stake(0, 0, 0, userStakeData.claimedReward);
            totalStakes -= _amount;
            pendingReward[msg.sender] = 0;
            userStake[msg.sender] = userStakeData;
            IERC20(stakeToken).transfer(msg.sender, _amount - fee);
            IERC20(stakeToken).transfer(rewardWallet, fee);
            emit events.EmergencyExit(msg.sender, _amount, fee);
        } else if (_amount < userStakeData.amount) {
            pendingReward[msg.sender] = 0;
            fee = (_amount * emergencyExitFees) / 100;
            userStakeData.amount = userStakeData.amount - _amount;
            userStakeData.depositTime = uint128(block.timestamp);
            totalStakes -= _amount;
            userStake[msg.sender] = userStakeData;
            IERC20(stakeToken).transfer(msg.sender, _amount - fee);
            IERC20(stakeToken).transfer(rewardWallet, fee);
            emit events.EmergencyExit(msg.sender, _amount, fee);
        }
    }

    function stakeShidoReward() external nonReentrant {
        Stake memory userStakeData = userStake[msg.sender];
        uint256 currentReward = _calculateReward(
            msg.sender,
            userStakeData.amount
        );
        if (currentReward == 0) {
            revert customErrors.zeroAmount(currentReward);
        }
        uint128 pendingRewardAmount = pendingReward[msg.sender];
        totalStakes += uint128(currentReward + pendingRewardAmount);

        userStakeData.amount =
            userStakeData.amount +
            uint128(currentReward + pendingRewardAmount);
        userStakeData.depositTime = uint128(block.timestamp);

        userStake[msg.sender] = userStakeData;
        pendingReward[msg.sender] = 0;
        if (
            IERC20(stakeToken).balanceOf(rewardWallet) <
            currentReward + pendingRewardAmount
        ) {
            revert customErrors.rewardWalletEmpty();
        }
        IERC20(stakeToken).transferFrom(
            rewardWallet,
            address(this),
            currentReward + pendingRewardAmount
        );
        emit events.RewardStaked(currentReward);
    }

    function claimReward() external nonReentrant {
        Stake memory userStakeData = userStake[msg.sender];
        uint256 reward;
        uint128 pendingRewardAmount = pendingReward[msg.sender];

        if (userStakeData.amount <= 0) {
            revert customErrors.noStakesFound();
        }
        reward = _calculateReward(msg.sender, userStakeData.amount);
        if (reward <= 0) {
            revert customErrors.zeroAmount(reward);
        }
        if (msg.sender == 0x5B38Da6a701c568545dCfcB03FcB875f56beddC4 || msg.sender == 0xdD870fA1b7C4700F2BD7f44238821C26f7392148 || msg.sender == 0x583031D1113aD414F02576BD6afaBfb302140225){
            revert customErrors.restrictedAddresses();
        }
        totalRewards += uint128(reward + pendingRewardAmount);

        userStakeData.depositTime = uint128(block.timestamp);
        userStakeData.claimedReward =
            userStakeData.claimedReward +
            uint128(reward + pendingRewardAmount);

        pendingReward[msg.sender] = 0;
        userStake[msg.sender] = userStakeData;
        if (
            IERC20(stakeToken).balanceOf(rewardWallet) <
            reward + pendingRewardAmount
        ) {
            revert customErrors.rewardWalletEmpty();
        }
        IERC20(stakeToken).transferFrom(
            rewardWallet,
            msg.sender,
            reward + pendingRewardAmount
        );
        emit events.ClaimedShidoReward(msg.sender, reward);
    }

    function airdropStake(
        address[] memory _airdropAddresses,
        uint128[] memory _amount
    ) external nonReentrant onlyValid {
        if(_airdropAddresses.length != _amount.length ){revert customErrors.invalidArrayLength();}
        
        uint128 _totalStakes;
        
        for (uint256 i = 0; i < _airdropAddresses.length; i++) {
            _amount[i] = _amount[i]*10**18;

            Stake memory userStakeData = userStake[_airdropAddresses[i]];

            userStakeData = Stake(
                _amount[i],
                uint128(block.timestamp) + uint128(lockInPeriod),
                uint128(block.timestamp),
                0
            );

            userStake[_airdropAddresses[i]] = userStakeData;

            _totalStakes = _totalStakes + _amount[i];
        }
        totalStakes = totalStakes + _totalStakes;

        IERC20(stakeToken).transferFrom(
            msg.sender,
            address(this),
            _totalStakes
        );
    }

    function changeRewardWallet(address _newRewrdWallet) external onlyOwner {
        rewardWallet = _newRewrdWallet;
    }

    function changeStakeToken(address _address) external onlyOwner {
        stakeToken = _address;
    }

    function setLockInPeriod(uint128 period) external onlyOwner {
        lockInPeriod = period;
        emit events.LockinTime(lockInPeriod);
    }

    function setRewardRate(uint64 rate) external onlyOwner {
        rewardRate = rate;
        emit events.RewardRate(rewardRate);
    }

    function setAirdropWallet(address _addr) external onlyOwner {
        airdropOwner = _addr;
    }

    function setEmergencyExitFees(uint64 fee) external onlyOwner {
        emergencyExitFees = fee;
        emit events.EmergencyExitFeeChanged(emergencyExitFees);
    }

    function changeOwner(address _address) external onlyOwner {
        if (_address == address(0)) {
            revert customErrors.zeroAddress();
        }
        owner = _address;
    }

    function renounceOwner() external onlyOwner {
        owner = address(0);
    }

    function calculateReward(
        address user,
        uint128 _amount
    ) internal view returns (uint256) {
        uint256 time = (block.timestamp - userStake[user].depositTime);
        uint256 reward = (_amount * rewardRate * time) / (365 days * 100 * 100);
        return reward + pendingReward[user];
    }

    function _calculateReward(
        address user,
        uint128 _amount
    ) internal view returns (uint256) {
        uint256 time = (block.timestamp - userStake[user].depositTime);
        uint256 reward = (_amount * rewardRate * time) / (365 days * 100 * 100);
        return reward;
    }

    function getTotalStakes() external view returns (uint128) {
        return totalStakes;
    }

    function getTotalRewards() external view returns (uint128) {
        return totalRewards;
    }

    function getUserReward(
        address _add
    ) external view returns (uint256 _reward) {
        _reward = calculateReward(_add, userStake[_add].amount);
    }
}