ETH Price: $1,977.52 (-4.67%)

Transaction Decoder

Block:
20027436 at Jun-05-2024 06:31:59 PM +UTC
Transaction Fee:
0.000583668743494122 ETH $1.15
Gas Used:
29,007 Gas / 20.121651446 Gwei

Emitted Events:

259 Staking.OwnershipTransferred( previousOwner=[Sender] 0x8f369c8ffb7fd886a0820bbc017dc7da67b84971, newOwner=0x792B90ce...27dfa79dA )

Account State Difference:

  Address   Before After State Difference Code
(Titan Builder)
8.031449065836751509 Eth8.031451966536751509 Eth0.0000029007
0x8F369c8F...a67B84971
0.00879771685386449 Eth
Nonce: 5
0.008214048110370368 Eth
Nonce: 6
0.000583668743494122
0xF0BA817b...E3e703D5B

Execution Trace

Staking.transferOwnership( newOwner=0x792B90ce41548dFC3fB88E6Af5a6f3C27dfa79dA )
/**
 *Submitted for verification at Etherscan.io on 2023-12-18
*/

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.23;


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 value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` 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 value) external returns (bool);
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

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].
     *
     * CAUTION: See Security Considerations above.
     */
    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);
}
library Address {
    /**
     * @dev The ETH balance of the account is not enough to perform the operation.
     */
    error AddressInsufficientBalance(address account);

    /**
     * @dev There's no code at `target` (it is not a contract).
     */
    error AddressEmptyCode(address target);

    /**
     * @dev A call to an address target failed. The target may have reverted.
     */
    error FailedInnerCall();

    /**
     * @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/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        if (address(this).balance < amount) {
            revert AddressInsufficientBalance(address(this));
        }

        (bool success, ) = recipient.call{value: amount}("");
        if (!success) {
            revert FailedInnerCall();
        }
    }

    /**
     * @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 or custom error, it is bubbled
     * up by this function (like regular Solidity function calls). However, if
     * the call reverted with no returned reason, this function reverts with a
     * {FailedInnerCall} error.
     *
     * 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.
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    /**
     * @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`.
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        if (address(this).balance < value) {
            revert AddressInsufficientBalance(address(this));
        }
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
     * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
     * unsuccessful call.
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata
    ) internal view returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            // only check if target is a contract if the call was successful and the return data is empty
            // otherwise we already know that it was a contract
            if (returndata.length == 0 && target.code.length == 0) {
                revert AddressEmptyCode(target);
            }
            return returndata;
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
     * revert reason or with a default {FailedInnerCall} error.
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            return returndata;
        }
    }

    /**
     * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
     */
    function _revert(bytes memory returndata) 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 FailedInnerCall();
        }
    }
}
// library SafeERC20 {
//     using Address for address;

//     /**
//      * @dev An operation with an ERC20 token failed.
//      */
//     error SafeERC20FailedOperation(address token);

//     /**
//      * @dev Indicates a failed `decreaseAllowance` request.
//      */
//     error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

//     /**
//      * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
//     //  * non-reverting calls are assumed to be successful.
//     //  */
//     // function transfer(IERC20 token, address to, uint256 value) internal {
//     //     _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
//     // }

//     /**
//      * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
//      * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
//      */
//     // function transferFrom(IERC20 token, address from, address to, uint256 value) internal {
//     //     _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
//     // }

//     /**
//      * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
//      * non-reverting calls are assumed to be successful.
//      */
//     function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
//         uint256 oldAllowance = token.allowance(address(this), spender);
//         forceApprove(token, spender, oldAllowance + value);
//     }

//     /**
//      * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
//      * value, non-reverting calls are assumed to be successful.
//      */
//     function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
//         unchecked {
//             uint256 currentAllowance = token.allowance(address(this), spender);
//             if (currentAllowance < requestedDecrease) {
//                 revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
//             }
//             forceApprove(token, spender, currentAllowance - requestedDecrease);
//         }
//     }

//     /**
//      * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
//      * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
//      * to be set to zero before setting it to a non-zero value, such as USDT.
//      */
//     function forceApprove(IERC20 token, address spender, uint256 value) internal {
//         bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));

//         if (!_callOptionalReturnBool(token, approvalCall)) {
//             _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
//             _callOptionalReturn(token, approvalCall);
//         }
//     }

//     /**
//      * @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);
//         if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
//             revert SafeERC20FailedOperation(address(token));
//         }
//     }

//     /**
//      * @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).
//      *
//      * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
//      */
//     function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
//         // 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 cannot use {Address-functionCall} here since this should return false
//         // and not revert is the subcall reverts.

//         (bool success, bytes memory returndata) = address(token).call(data);
//         return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
//     }
// }

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
abstract contract Ownable is Context {
    address private _owner;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @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 {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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 {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _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);
    }
}
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;

    /**
     * @dev Unauthorized reentrant call.
     */
    error ReentrancyGuardReentrantCall();

    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
        if (_status == ENTERED) {
            revert ReentrancyGuardReentrantCall();
        }

        // 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 EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position is the index of the value in the `values` array plus 1.
        // Position 0 is used to mean a value is not in the set.
        mapping(bytes32 value => uint256) _positions;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._positions[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We cache the value's position to prevent multiple reads from the same storage slot
        uint256 position = set._positions[value];

        if (position != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 valueIndex = position - 1;
            uint256 lastIndex = set._values.length - 1;

            if (valueIndex != lastIndex) {
                bytes32 lastValue = set._values[lastIndex];

                // Move the lastValue to the index where the value to delete is
                set._values[valueIndex] = lastValue;
                // Update the tracked position of the lastValue (that was just moved)
                set._positions[lastValue] = position;
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the tracked position for the deleted slot
            delete set._positions[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._positions[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        bytes32[] memory store = _values(set._inner);
        bytes32[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}
contract Staking is Ownable, ReentrancyGuard {
    // using SafeERC20 for IERC20;
    using EnumerableSet for EnumerableSet.UintSet;

    struct StakeInfo {
        uint256 id;
        uint256 amount;
        uint256 stakeDate;
        uint256 lastClaimDate;
        uint256 startPeriod;
        uint256 finishPeriod;
    }

    uint256 public startDate;
    uint256 public finishDate;
    uint256 public totalStaked;
    uint256 public totalPenalty;
    uint256 public stakeCount;
    uint256 public penaltyPercentage;
    uint256 public rewardCounter;

    IERC20 public stakingToken;
    IERC20 public rewardToken;

    mapping(address wallet => uint256) public stakeIdCount;
    mapping(address wallet => EnumerableSet.UintSet) private _stakeIdsPerWallet;
    mapping(address wallet => mapping(uint256 id => StakeInfo)) public stakeInfo;

    event Stake(address indexed user, uint256 indexed amount, uint256 indexed stakeId);
    event Unstake(address indexed user, uint256 indexed amount, uint256 indexed stakeId);
    event Claim(address indexed user, uint256 indexed reward, uint256 indexed stakeId);
    event SetPeriod(uint256 indexed startDate, uint256 indexed finishDate);
    
    constructor(address _stakingToken, address _rewardToken, uint256 _penaltyPercentage) Ownable(msg.sender) {
        stakingToken = IERC20(_stakingToken);
        rewardToken = IERC20(_rewardToken);
        penaltyPercentage = _penaltyPercentage;
    }

    modifier isStakeIdExist(address _user, uint256 _stakeId) {
        bool isExist = _stakeIdsPerWallet[_user].contains(_stakeId);
        require(isExist, "You don't have stake with this stake id");
        _;
    }

    function stake(uint256 _amount) external nonReentrant {
        require(block.timestamp >= startDate && block.timestamp < finishDate, "Cannot stake outside staking period");

        stakingToken.transferFrom(msg.sender, address(this), _amount);
        totalStaked += _amount;
        stakeCount++;

        uint256 stakeId = stakeIdCount[msg.sender];
        _stakeIdsPerWallet[msg.sender].add(stakeId);
        stakeInfo[msg.sender][stakeId] = StakeInfo(stakeId, _amount, block.timestamp, 0, startDate, finishDate);
        stakeIdCount[msg.sender]++;

        emit Stake(msg.sender, _amount, stakeId);
    }

    function unstake(uint256 _id) external nonReentrant isStakeIdExist(msg.sender, _id) {
        uint256 penaltyAmount;
        uint256 amount = stakeInfo[msg.sender][_id].amount;
        uint256 _finishDate = stakeInfo[msg.sender][_id].finishPeriod;
        
        if (block.timestamp < _finishDate) {
            penaltyAmount = amount * penaltyPercentage / 100;
            amount -= penaltyAmount;
            totalPenalty += penaltyAmount;
        }

        _claimReward(msg.sender, _id);
        stakingToken.transfer(msg.sender, amount);
        stakeInfo[msg.sender][_id] = StakeInfo(0, 0, 0, 0, 0, 0);
        _stakeIdsPerWallet[msg.sender].remove(_id);
        totalStaked = totalStaked - (amount + penaltyAmount);
        stakeCount--;

        emit Unstake(msg.sender, amount + penaltyAmount, _id);
    }

    function claimReward(uint _id) public nonReentrant isStakeIdExist(msg.sender, _id) {
        _claimReward(msg.sender, _id);
    }

    function _claimReward(address _user, uint256 _id) private {
        uint256 rewards = calculateReward(_user, _id);
        rewardToken.transfer(_user, rewards);

        stakeInfo[_user][_id].lastClaimDate = block.timestamp > stakeInfo[_user][_id].finishPeriod ? stakeInfo[_user][_id].finishPeriod : block.timestamp;

        emit Claim(_user, rewards, _id);
    }

    function calculateReward(address _user, uint256 _stakeId) public isStakeIdExist(_user, _stakeId) view returns(uint256 rewards) {
        uint256 totalReward = getTotalReward();
        uint256 stakingTokenDecimals = stakingToken.decimals();
        uint256 rewardTokenDecimals = rewardToken.decimals();
        uint256 decimalsDifference = stakingTokenDecimals > rewardTokenDecimals ? stakingTokenDecimals - rewardTokenDecimals : rewardTokenDecimals - stakingTokenDecimals;
        StakeInfo memory _stakeInfo = stakeInfo[_user][_stakeId];
        uint256 convertedAmount = stakingTokenDecimals > rewardTokenDecimals ? _stakeInfo.amount / 10**decimalsDifference : _stakeInfo.amount * 10**decimalsDifference;
        uint256 convertedTotalStaked = stakingTokenDecimals > rewardTokenDecimals ? totalStaked / 10**decimalsDifference : totalStaked * 10**decimalsDifference;
        uint256 lastClaim = _stakeInfo.lastClaimDate > _stakeInfo.stakeDate ? _stakeInfo.lastClaimDate : _stakeInfo.stakeDate;
        uint256 claimTime = block.timestamp > _stakeInfo.finishPeriod ? _stakeInfo.finishPeriod : block.timestamp;
        uint256 stakeDuration = claimTime - lastClaim;
        uint256 stakePeriod = _stakeInfo.finishPeriod - _stakeInfo.startPeriod;
        rewards = (convertedAmount * stakeDuration * totalReward / convertedTotalStaked / stakePeriod);
    }

    function getTotalReward() public view returns(uint256) {
        return rewardCounter;
    }

    function rewardBalance() public view returns (uint256) {
        return  rewardToken.balanceOf(address(this));
    } 

    function getStakeIdList(address _user) public view returns(uint256[] memory stakeIds) {
        stakeIds = _stakeIdsPerWallet[_user].values();
    }

    function getStakeList(address _user) public view returns(StakeInfo[] memory stakeList) {
        uint256[] memory stakeIds = _stakeIdsPerWallet[_user].values();
        stakeList = new StakeInfo[](stakeIds.length);

        for (uint256 i; i < stakeIds.length; i++) 
        {
            stakeList[i] = stakeInfo[_user][stakeIds[i]];
        }
    }

    function setPenaltyPercentage(uint256 _percentage) external onlyOwner {
        penaltyPercentage = _percentage;
    }

    function setStakingRewardToken(address _stakingToken, address _rewardToken) external onlyOwner {
        stakingToken = IERC20(_stakingToken);
        rewardToken = IERC20(_rewardToken);
    }

    function setPeriod(uint256 _startDate, uint256 _finishDate) external onlyOwner {
        require(_startDate > block.timestamp, "Start date staking period must be greater than now");
        require(_finishDate > _startDate, "Finish date must be greater than start date");
        startDate = _startDate;
        finishDate = _finishDate;

        emit SetPeriod(_startDate, _finishDate);
    }

    function depositReward(uint256 _amount) external onlyOwner {
        rewardToken.transferFrom(msg.sender, address(this), _amount);
        rewardCounter += _amount;
    }

    function withdrawReward(uint256 _amount) external onlyOwner {
        rewardToken.transfer(msg.sender, _amount);
    }

    function withdrawPenalty() external onlyOwner {
        uint256 penalty = totalPenalty;
        stakingToken.transfer(address(stakingToken), penalty);
        totalPenalty -= penalty;
    }
}