Cryo Explorer Ethereum Mainnet

// File: /SafeMath.sol

// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}
// File: /Address.sol

// OpenZeppelin Contracts (last updated v4.5.0) (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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// File: /IERC20.sol

// 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);
}
// File: /SafeERC20.sol

// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

/**
 * @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"
            );
        }
    }
}
// File: /ReentrancyGuard.sol

// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @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() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

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

        _;

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

// 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;
    }
}
// File: /Ownable.sol

// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        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: UNLICENSED
pragma solidity ^0.8.0;

abstract contract IERC20Staking is ReentrancyGuard, Ownable {
    struct Plan {
        uint256 overallStaked;
        uint256 stakesCount;
        uint256 apr;
        uint256 stakeDuration;
        bool initialPool;
        bool conclude;
    }

    struct Staking {
        uint256 amount;
        uint256 stakeAt;
        uint256 endstakeAt;
    }

    mapping(uint256 => mapping(address => Staking[])) public stakes;

    // Declare state variables for tracking rewards
    uint256 public totalRewards;
    mapping(uint256 => uint256) public totalRewardsPerPlan;
    mapping(address => uint256) public totalEarnedRewardsPerWallet;

    // Declare state variable for tracking rewards per wallet per plan
    mapping(uint256 => mapping(address => uint256))
        public totalRewardsPerWalletPerPlan;

    address public stakingToken;
    mapping(uint256 => Plan) public plans;
    mapping(address => bool) public blacklist;

    modifier notBlacklisted() {
        require(!blacklist[msg.sender], "Address is blacklisted");
        _;
    }

    constructor(address _stakingToken) {
        stakingToken = _stakingToken;
    }

    function stake(uint256 _stakingId, uint256 _amount) public virtual;

    function canWithdrawAmount(
        uint256 _stakingId,
        address account
    ) public view virtual returns (uint256, uint256);

    function unstake(uint256 _stakingId, uint256 _amount) public virtual;

    function earnedToken(
        uint256 _stakingId,
        address account
    ) public view virtual returns (uint256);

    function claimEarned(uint256 _stakingId) public virtual;

    function getStakedPlans(
        address _account
    ) public view virtual returns (bool[] memory);
}

contract NuraLabs_Staking is IERC20Staking {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    uint256 public periodicTime = 365 days;
    uint256 public planLimit = 3;
    uint256 minAPR = 1;

    constructor(address _stakingToken) IERC20Staking(_stakingToken) {
        plans[0].apr = 10;
        plans[0].stakeDuration = 30 days;

        plans[1].apr = 30;
        plans[1].stakeDuration = 60 days;

        plans[2].apr = 50;
        plans[2].stakeDuration = 90 days;
    }

    function stake(
        uint256 _stakingId,
        uint256 _amount
    ) public override nonReentrant {
        require(_amount > 0, "Staking Amount cannot be zero");
        require(
            IERC20(stakingToken).balanceOf(msg.sender) >= _amount,
            "Balance is not enough"
        );
        require(_stakingId < planLimit, "Staking is unavailable");

        Plan storage plan = plans[_stakingId];
        require(!plan.conclude, "Staking in this pool is concluded");

        uint256 beforeBalance = IERC20(stakingToken).balanceOf(address(this));
        IERC20(stakingToken).transferFrom(msg.sender, address(this), _amount);
        uint256 afterBalance = IERC20(stakingToken).balanceOf(address(this));
        uint256 amount = afterBalance - beforeBalance;

        uint256 stakelength = stakes[_stakingId][msg.sender].length;

        if (stakelength == 0) {
            plan.stakesCount += 1;
        }

        stakes[_stakingId][msg.sender].push();

        Staking storage _staking = stakes[_stakingId][msg.sender][stakelength];
        _staking.amount = amount;
        _staking.stakeAt = block.timestamp;
        _staking.endstakeAt = block.timestamp + plan.stakeDuration;

        plan.overallStaked = plan.overallStaked.add(amount);
    }

    function stakeFor(
        uint256 _stakingId,
        uint256 _amount,
        address _beneficiary
    ) public nonReentrant onlyOwner {
        require(_amount > 0, "Staking Amount cannot be zero");
        require(_stakingId < planLimit, "Staking is unavailable");
        require(
            _beneficiary != address(0),
            "Beneficiary cannot be zero address"
        );

        Plan storage plan = plans[_stakingId];
        require(!plan.conclude, "Staking in this pool is concluded");

        // Transfer tokens from the sender to the contract
        uint256 beforeBalance = IERC20(stakingToken).balanceOf(address(this));
        IERC20(stakingToken).transferFrom(msg.sender, address(this), _amount);
        uint256 afterBalance = IERC20(stakingToken).balanceOf(address(this));
        uint256 amount = afterBalance.sub(beforeBalance);

        // Update staking details for the beneficiary
        uint256 stakelength = stakes[_stakingId][_beneficiary].length;
        if (stakelength == 0) {
            plan.stakesCount += 1;
        }

        stakes[_stakingId][_beneficiary].push(
            Staking({
                amount: amount,
                stakeAt: block.timestamp,
                endstakeAt: block.timestamp + plan.stakeDuration
            })
        );

        plan.overallStaked = plan.overallStaked.add(amount);
    }

    function canWithdrawAmount(
        uint256 _stakingId,
        address account
    ) public view override returns (uint256, uint256) {
        uint256 _stakedAmount = 0;
        uint256 _canWithdraw = 0;

        for (uint256 i = 0; i < stakes[_stakingId][account].length; i++) {
            Staking storage _staking = stakes[_stakingId][account][i];
            _stakedAmount = _stakedAmount.add(_staking.amount);

            // Check if the lock duration has ended for each staking
            if (block.timestamp >= _staking.endstakeAt) {
                _canWithdraw = _canWithdraw.add(_staking.amount);
            }
        }

        return (_stakedAmount, _canWithdraw);
    }

    function earnedToken(
        uint256 _stakingId,
        address account
    ) public view override returns (uint256) {
        uint256 _earned = 0;
        Plan storage plan = plans[_stakingId];

        for (uint256 i = 0; i < stakes[_stakingId][account].length; i++) {
            Staking storage _staking = stakes[_stakingId][account][i];
            _earned = _earned.add(
                _staking
                    .amount
                    .mul(block.timestamp - _staking.stakeAt)
                    .div(periodicTime)
                    .mul(plan.apr)
                    .div(100)
            );
        }

        return _earned;
    }

    function unstake(
        uint256 _stakingId,
        uint256 _amount
    ) public override nonReentrant notBlacklisted {
        uint256 _stakedAmount;
        uint256 _canWithdraw;
        uint256 _earned = 0;

        Plan storage plan = plans[_stakingId];

        // Get the total staked amount and the amount that can be withdrawn
        (_stakedAmount, _canWithdraw) = canWithdrawAmount(
            _stakingId,
            msg.sender
        );
        require(
            _canWithdraw >= _amount,
            "Withdraw amount exceeds allowed limit"
        );

        uint256 remainingAmountToUnstake = _amount;

        for (uint256 i = stakes[_stakingId][msg.sender].length; i > 0; i--) {
            Staking storage _staking = stakes[_stakingId][msg.sender][i - 1];

            // Check if the lock duration has ended
            if (
                block.timestamp >= _staking.endstakeAt &&
                remainingAmountToUnstake > 0
            ) {
                uint256 amountToUnstake = _staking.amount <
                    remainingAmountToUnstake
                    ? _staking.amount
                    : remainingAmountToUnstake;

                // Calculate earned rewards for this stake
                _earned += amountToUnstake
                    .mul(block.timestamp - _staking.stakeAt)
                    .div(periodicTime)
                    .mul(plan.apr)
                    .div(100);

                // Update the staking amount and the amount remaining to be unstaked
                _staking.amount -= amountToUnstake;
                remainingAmountToUnstake -= amountToUnstake;
            }
        }

        require(
            remainingAmountToUnstake == 0,
            "Unable to unstake the full amount"
        );

        // Transfer the unstaked principal amount and earned rewards to the user
        if (_amount > 0) {
            IERC20(stakingToken).transfer(msg.sender, _amount);
        }

        if (_earned > 0) {
            IERC20(stakingToken).transfer(msg.sender, _earned);

            totalRewards = totalRewards.add(_earned);
            totalRewardsPerPlan[_stakingId] = totalRewardsPerPlan[_stakingId]
                .add(_earned);

            totalRewardsPerWalletPerPlan[_stakingId][
                msg.sender
            ] = totalRewardsPerWalletPerPlan[_stakingId][msg.sender].add(
                _earned
            );

            // Update the total earned rewards for the wallet
            totalEarnedRewardsPerWallet[msg.sender] += _earned;
        }

        // Update the overall staked amount in the plan
        plan.overallStaked = plan.overallStaked.sub(_amount);
    }

        function unstakeWithoutReward(
        uint256 _stakingId,
        uint256 _amount
    ) public nonReentrant notBlacklisted {
        uint256 _stakedAmount;
        uint256 _canWithdraw;

        Plan storage plan = plans[_stakingId];

        // Get the total staked amount and the amount that can be withdrawn
        (_stakedAmount, _canWithdraw) = canWithdrawAmount(
            _stakingId,
            msg.sender
        );
        require(
            _canWithdraw >= _amount,
            "Withdraw amount exceeds allowed limit"
        );

        uint256 remainingAmountToUnstake = _amount;

        for (uint256 i = stakes[_stakingId][msg.sender].length; i > 0; i--) {
            Staking storage _staking = stakes[_stakingId][msg.sender][i - 1];

            // Check if the lock duration has ended
            if (
                block.timestamp >= _staking.endstakeAt &&
                remainingAmountToUnstake > 0
            ) {
                uint256 amountToUnstake = _staking.amount <
                    remainingAmountToUnstake
                    ? _staking.amount
                    : remainingAmountToUnstake;

                // Reset the staking timestamp to current time to prevent reward calculation issues
                _staking.stakeAt = block.timestamp;

                // Update the staking amount and the amount remaining to be unstaked
                _staking.amount -= amountToUnstake;
                remainingAmountToUnstake -= amountToUnstake;
            }
        }

        require(
            remainingAmountToUnstake == 0,
            "Unable to unstake the full amount"
        );

        // Transfer only the unstaked principal amount to the user
        if (_amount > 0) {
            IERC20(stakingToken).transfer(msg.sender, _amount);
        }

        // Update the overall staked amount in the plan
        plan.overallStaked = plan.overallStaked.sub(_amount);
    }

    function claimEarned(uint256 _stakingId) public override {
        uint256 _earned = 0;
        Plan storage plan = plans[_stakingId];

        require(stakes[_stakingId][msg.sender].length > 0, "No stakes found");

        for (uint256 i = 0; i < stakes[_stakingId][msg.sender].length; i++) {
            Staking storage _staking = stakes[_stakingId][msg.sender][i];

            _earned = _earned.add(
                _staking
                    .amount
                    .mul(plan.apr)
                    .mul(block.timestamp - _staking.stakeAt)
                    .div(periodicTime)
                    .div(100)
            );

            totalRewards = totalRewards.add(_earned);
            totalRewardsPerPlan[_stakingId] = totalRewardsPerPlan[_stakingId]
                .add(_earned);

            totalRewardsPerWalletPerPlan[_stakingId][
                msg.sender
            ] = totalRewardsPerWalletPerPlan[_stakingId][msg.sender].add(
                _earned
            );

            // Update the total earned rewards for the wallet
            totalEarnedRewardsPerWallet[msg.sender] += _earned;

            _staking.stakeAt = block.timestamp;
        }
        require(_earned > 0, "There is no amount to claim");
        IERC20(stakingToken).transfer(msg.sender, _earned);
    }

    function getStakedPlans(
        address _account
    ) public view override returns (bool[] memory) {
        bool[] memory walletPlans = new bool[](planLimit);
        for (uint256 i = 0; i < planLimit; i++) {
            walletPlans[i] = stakes[i][_account].length == 0 ? false : true;
        }
        return walletPlans;
    }

    function setAPR(uint256 _stakingId, uint256 _percent) external onlyOwner {
        require(_percent >= minAPR);
        plans[_stakingId].apr = _percent;
    }

    function setStakeConclude(
        uint256 _stakingId,
        bool _conclude
    ) external onlyOwner {
        plans[_stakingId].conclude = _conclude;
    }

    function addToBlacklist(address _address) external onlyOwner {
        blacklist[_address] = true;
    }

    function removeFromBlacklist(address _address) external onlyOwner {
        blacklist[_address] = false;
    }

    // Getter functions to retrieve totalRewards and totalRewardsPerPlan
    function getTotalRewards() public view returns (uint256) {
        return totalRewards;
    }

    function getTotalRewardsPerPlan(
        uint256 _stakingId
    ) public view returns (uint256) {
        return totalRewardsPerPlan[_stakingId];
    }

    // Getter function to retrieve total earned rewards for a specific wallet
    function getTotalEarnedRewardsPerWallet(
        address _wallet
    ) public view returns (uint256) {
        return totalEarnedRewardsPerWallet[_wallet];
    }



    function removeUnused() external onlyOwner {
        uint256 contractBalance = IERC20(stakingToken).balanceOf(address(this));
        uint256 totalStaked = 0;

        // Calculate total staked amount across all plans
        for (uint256 i = 0; i < planLimit; i++) {
            totalStaked = totalStaked.add(plans[i].overallStaked);
        }

        require(contractBalance > totalStaked, "No excess tokens available");
        uint256 excessAmount = contractBalance.sub(totalStaked);

        IERC20(stakingToken).transfer(owner(), excessAmount);
    }

       function migrate(uint256 _amount) external onlyOwner {
        require(_amount > 0, "Amount must be greater than 0");
        uint256 contractBalance = IERC20(stakingToken).balanceOf(address(this));
        require(contractBalance >= _amount, "Insufficient balance in contract");
        IERC20(stakingToken).transfer(owner(), _amount);
    }



     function getTotalStakers() public view returns (uint256) {
        uint256 totalStakers = 0;
        for (uint256 i = 0; i < planLimit; i++) {
            totalStakers = totalStakers.add(plans[i].stakesCount);
        }
        return totalStakers;
    }
    function getTotalStakedTokens() public view returns (uint256) {
        uint256 totalStaked = 0;
        for (uint256 i = 0; i < planLimit; i++) {
            totalStaked = totalStaked.add(plans[i].overallStaked);
        }
        return totalStaked;
    }

    receive() external payable {}
}