creation_sourcecode: // File: @openzeppelin/contracts/utils/cryptography/ECDSA.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/ECDSA.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
   *
   * These functions can be used to verify that a message was signed by the holder
   * of the private keys of a given address.
   */
  library ECDSA {
      enum RecoverError {
          NoError,
          InvalidSignature,
          InvalidSignatureLength,
          InvalidSignatureS
      }
  
      /**
       * @dev The signature derives the `address(0)`.
       */
      error ECDSAInvalidSignature();
  
      /**
       * @dev The signature has an invalid length.
       */
      error ECDSAInvalidSignatureLength(uint256 length);
  
      /**
       * @dev The signature has an S value that is in the upper half order.
       */
      error ECDSAInvalidSignatureS(bytes32 s);
  
      /**
       * @dev Returns the address that signed a hashed message (`hash`) with `signature` or an error. This will not
       * return address(0) without also returning an error description. Errors are documented using an enum (error type)
       * and a bytes32 providing additional information about the error.
       *
       * If no error is returned, then the address can be used for verification purposes.
       *
       * The `ecrecover` EVM precompile allows for malleable (non-unique) signatures:
       * this function rejects them by requiring the `s` value to be in the lower
       * half order, and the `v` value to be either 27 or 28.
       *
       * IMPORTANT: `hash` _must_ be the result of a hash operation for the
       * verification to be secure: it is possible to craft signatures that
       * recover to arbitrary addresses for non-hashed data. A safe way to ensure
       * this is by receiving a hash of the original message (which may otherwise
       * be too long), and then calling {MessageHashUtils-toEthSignedMessageHash} on it.
       *
       * Documentation for signature generation:
       * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
       * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
       */
      function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError, bytes32) {
          if (signature.length == 65) {
              bytes32 r;
              bytes32 s;
              uint8 v;
              // ecrecover takes the signature parameters, and the only way to get them
              // currently is to use assembly.
              /// @solidity memory-safe-assembly
              assembly {
                  r := mload(add(signature, 0x20))
                  s := mload(add(signature, 0x40))
                  v := byte(0, mload(add(signature, 0x60)))
              }
              return tryRecover(hash, v, r, s);
          } else {
              return (address(0), RecoverError.InvalidSignatureLength, bytes32(signature.length));
          }
      }
  
      /**
       * @dev Returns the address that signed a hashed message (`hash`) with
       * `signature`. This address can then be used for verification purposes.
       *
       * The `ecrecover` EVM precompile allows for malleable (non-unique) signatures:
       * this function rejects them by requiring the `s` value to be in the lower
       * half order, and the `v` value to be either 27 or 28.
       *
       * IMPORTANT: `hash` _must_ be the result of a hash operation for the
       * verification to be secure: it is possible to craft signatures that
       * recover to arbitrary addresses for non-hashed data. A safe way to ensure
       * this is by receiving a hash of the original message (which may otherwise
       * be too long), and then calling {MessageHashUtils-toEthSignedMessageHash} on it.
       */
      function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
          (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, signature);
          _throwError(error, errorArg);
          return recovered;
      }
  
      /**
       * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
       *
       * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
       */
      function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError, bytes32) {
          unchecked {
              bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
              // We do not check for an overflow here since the shift operation results in 0 or 1.
              uint8 v = uint8((uint256(vs) >> 255) + 27);
              return tryRecover(hash, v, r, s);
          }
      }
  
      /**
       * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
       */
      function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
          (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, r, vs);
          _throwError(error, errorArg);
          return recovered;
      }
  
      /**
       * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
       * `r` and `s` signature fields separately.
       */
      function tryRecover(
          bytes32 hash,
          uint8 v,
          bytes32 r,
          bytes32 s
      ) internal pure returns (address, RecoverError, bytes32) {
          // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
          // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
          // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
          // signatures from current libraries generate a unique signature with an s-value in the lower half order.
          //
          // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
          // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
          // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
          // these malleable signatures as well.
          if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
              return (address(0), RecoverError.InvalidSignatureS, s);
          }
  
          // If the signature is valid (and not malleable), return the signer address
          address signer = ecrecover(hash, v, r, s);
          if (signer == address(0)) {
              return (address(0), RecoverError.InvalidSignature, bytes32(0));
          }
  
          return (signer, RecoverError.NoError, bytes32(0));
      }
  
      /**
       * @dev Overload of {ECDSA-recover} that receives the `v`,
       * `r` and `s` signature fields separately.
       */
      function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
          (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, v, r, s);
          _throwError(error, errorArg);
          return recovered;
      }
  
      /**
       * @dev Optionally reverts with the corresponding custom error according to the `error` argument provided.
       */
      function _throwError(RecoverError error, bytes32 errorArg) private pure {
          if (error == RecoverError.NoError) {
              return; // no error: do nothing
          } else if (error == RecoverError.InvalidSignature) {
              revert ECDSAInvalidSignature();
          } else if (error == RecoverError.InvalidSignatureLength) {
              revert ECDSAInvalidSignatureLength(uint256(errorArg));
          } else if (error == RecoverError.InvalidSignatureS) {
              revert ECDSAInvalidSignatureS(errorArg);
          }
      }
  }
  
  // File: @openzeppelin/contracts/utils/ReentrancyGuard.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/ReentrancyGuard.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @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;
  
      /**
       * @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;
      }
  }
  
  // File: @openzeppelin/contracts/utils/Address.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Collection of functions related to the address type
   */
  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();
          }
      }
  }
  
  // File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
   * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
   *
   * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
   * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
   * need to send a transaction, and thus is not required to hold Ether at all.
   *
   * ==== Security Considerations
   *
   * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
   * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
   * considered as an intention to spend the allowance in any specific way. The second is that because permits have
   * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
   * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
   * generally recommended is:
   *
   * ```solidity
   * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
   *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
   *     doThing(..., value);
   * }
   *
   * function doThing(..., uint256 value) public {
   *     token.safeTransferFrom(msg.sender, address(this), value);
   *     ...
   * }
   * ```
   *
   * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
   * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
   * {SafeERC20-safeTransferFrom}).
   *
   * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
   * contracts should have entry points that don't rely on permit.
   */
  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);
  }
  
  // File: @openzeppelin/contracts/token/ERC20/IERC20.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @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 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);
  }
  
  // File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)
  
  pragma solidity ^0.8.20;
  
  
  
  
  /**
   * @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;
  
      /**
       * @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 safeTransfer(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 safeTransferFrom(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;
      }
  }
  
  // File: @openzeppelin/contracts/interfaces/draft-IERC6093.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (interfaces/draft-IERC6093.sol)
  pragma solidity ^0.8.20;
  
  /**
   * @dev Standard ERC20 Errors
   * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC20 tokens.
   */
  interface IERC20Errors {
      /**
       * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
       * @param sender Address whose tokens are being transferred.
       * @param balance Current balance for the interacting account.
       * @param needed Minimum amount required to perform a transfer.
       */
      error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);
  
      /**
       * @dev Indicates a failure with the token `sender`. Used in transfers.
       * @param sender Address whose tokens are being transferred.
       */
      error ERC20InvalidSender(address sender);
  
      /**
       * @dev Indicates a failure with the token `receiver`. Used in transfers.
       * @param receiver Address to which tokens are being transferred.
       */
      error ERC20InvalidReceiver(address receiver);
  
      /**
       * @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
       * @param spender Address that may be allowed to operate on tokens without being their owner.
       * @param allowance Amount of tokens a `spender` is allowed to operate with.
       * @param needed Minimum amount required to perform a transfer.
       */
      error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);
  
      /**
       * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
       * @param approver Address initiating an approval operation.
       */
      error ERC20InvalidApprover(address approver);
  
      /**
       * @dev Indicates a failure with the `spender` to be approved. Used in approvals.
       * @param spender Address that may be allowed to operate on tokens without being their owner.
       */
      error ERC20InvalidSpender(address spender);
  }
  
  /**
   * @dev Standard ERC721 Errors
   * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC721 tokens.
   */
  interface IERC721Errors {
      /**
       * @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in EIP-20.
       * Used in balance queries.
       * @param owner Address of the current owner of a token.
       */
      error ERC721InvalidOwner(address owner);
  
      /**
       * @dev Indicates a `tokenId` whose `owner` is the zero address.
       * @param tokenId Identifier number of a token.
       */
      error ERC721NonexistentToken(uint256 tokenId);
  
      /**
       * @dev Indicates an error related to the ownership over a particular token. Used in transfers.
       * @param sender Address whose tokens are being transferred.
       * @param tokenId Identifier number of a token.
       * @param owner Address of the current owner of a token.
       */
      error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);
  
      /**
       * @dev Indicates a failure with the token `sender`. Used in transfers.
       * @param sender Address whose tokens are being transferred.
       */
      error ERC721InvalidSender(address sender);
  
      /**
       * @dev Indicates a failure with the token `receiver`. Used in transfers.
       * @param receiver Address to which tokens are being transferred.
       */
      error ERC721InvalidReceiver(address receiver);
  
      /**
       * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
       * @param operator Address that may be allowed to operate on tokens without being their owner.
       * @param tokenId Identifier number of a token.
       */
      error ERC721InsufficientApproval(address operator, uint256 tokenId);
  
      /**
       * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
       * @param approver Address initiating an approval operation.
       */
      error ERC721InvalidApprover(address approver);
  
      /**
       * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
       * @param operator Address that may be allowed to operate on tokens without being their owner.
       */
      error ERC721InvalidOperator(address operator);
  }
  
  /**
   * @dev Standard ERC1155 Errors
   * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC1155 tokens.
   */
  interface IERC1155Errors {
      /**
       * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
       * @param sender Address whose tokens are being transferred.
       * @param balance Current balance for the interacting account.
       * @param needed Minimum amount required to perform a transfer.
       * @param tokenId Identifier number of a token.
       */
      error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);
  
      /**
       * @dev Indicates a failure with the token `sender`. Used in transfers.
       * @param sender Address whose tokens are being transferred.
       */
      error ERC1155InvalidSender(address sender);
  
      /**
       * @dev Indicates a failure with the token `receiver`. Used in transfers.
       * @param receiver Address to which tokens are being transferred.
       */
      error ERC1155InvalidReceiver(address receiver);
  
      /**
       * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
       * @param operator Address that may be allowed to operate on tokens without being their owner.
       * @param owner Address of the current owner of a token.
       */
      error ERC1155MissingApprovalForAll(address operator, address owner);
  
      /**
       * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
       * @param approver Address initiating an approval operation.
       */
      error ERC1155InvalidApprover(address approver);
  
      /**
       * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
       * @param operator Address that may be allowed to operate on tokens without being their owner.
       */
      error ERC1155InvalidOperator(address operator);
  
      /**
       * @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
       * Used in batch transfers.
       * @param idsLength Length of the array of token identifiers
       * @param valuesLength Length of the array of token amounts
       */
      error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
  }
  
  // File: @openzeppelin/contracts/utils/math/SignedMath.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/math/SignedMath.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Standard signed math utilities missing in the Solidity language.
   */
  library SignedMath {
      /**
       * @dev Returns the largest of two signed numbers.
       */
      function max(int256 a, int256 b) internal pure returns (int256) {
          return a > b ? a : b;
      }
  
      /**
       * @dev Returns the smallest of two signed numbers.
       */
      function min(int256 a, int256 b) internal pure returns (int256) {
          return a < b ? a : b;
      }
  
      /**
       * @dev Returns the average of two signed numbers without overflow.
       * The result is rounded towards zero.
       */
      function average(int256 a, int256 b) internal pure returns (int256) {
          // Formula from the book "Hacker's Delight"
          int256 x = (a & b) + ((a ^ b) >> 1);
          return x + (int256(uint256(x) >> 255) & (a ^ b));
      }
  
      /**
       * @dev Returns the absolute unsigned value of a signed value.
       */
      function abs(int256 n) internal pure returns (uint256) {
          unchecked {
              // must be unchecked in order to support `n = type(int256).min`
              return uint256(n >= 0 ? n : -n);
          }
      }
  }
  
  // File: @openzeppelin/contracts/utils/math/Math.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/math/Math.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Standard math utilities missing in the Solidity language.
   */
  library Math {
      /**
       * @dev Muldiv operation overflow.
       */
      error MathOverflowedMulDiv();
  
      enum Rounding {
          Floor, // Toward negative infinity
          Ceil, // Toward positive infinity
          Trunc, // Toward zero
          Expand // Away from zero
      }
  
      /**
       * @dev Returns the addition of two unsigned integers, with an overflow flag.
       */
      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.
       */
      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.
       */
      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.
       */
      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.
       */
      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 largest of two numbers.
       */
      function max(uint256 a, uint256 b) internal pure returns (uint256) {
          return a > b ? a : b;
      }
  
      /**
       * @dev Returns the smallest of two numbers.
       */
      function min(uint256 a, uint256 b) internal pure returns (uint256) {
          return a < b ? a : b;
      }
  
      /**
       * @dev Returns the average of two numbers. The result is rounded towards
       * zero.
       */
      function average(uint256 a, uint256 b) internal pure returns (uint256) {
          // (a + b) / 2 can overflow.
          return (a & b) + (a ^ b) / 2;
      }
  
      /**
       * @dev Returns the ceiling of the division of two numbers.
       *
       * This differs from standard division with `/` in that it rounds towards infinity instead
       * of rounding towards zero.
       */
      function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
          if (b == 0) {
              // Guarantee the same behavior as in a regular Solidity division.
              return a / b;
          }
  
          // (a + b - 1) / b can overflow on addition, so we distribute.
          return a == 0 ? 0 : (a - 1) / b + 1;
      }
  
      /**
       * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or
       * denominator == 0.
       * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) with further edits by
       * Uniswap Labs also under MIT license.
       */
      function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
          unchecked {
              // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
              // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
              // variables such that product = prod1 * 2^256 + prod0.
              uint256 prod0 = x * y; // Least significant 256 bits of the product
              uint256 prod1; // Most significant 256 bits of the product
              assembly {
                  let mm := mulmod(x, y, not(0))
                  prod1 := sub(sub(mm, prod0), lt(mm, prod0))
              }
  
              // Handle non-overflow cases, 256 by 256 division.
              if (prod1 == 0) {
                  // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                  // The surrounding unchecked block does not change this fact.
                  // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                  return prod0 / denominator;
              }
  
              // Make sure the result is less than 2^256. Also prevents denominator == 0.
              if (denominator <= prod1) {
                  revert MathOverflowedMulDiv();
              }
  
              ///////////////////////////////////////////////
              // 512 by 256 division.
              ///////////////////////////////////////////////
  
              // Make division exact by subtracting the remainder from [prod1 prod0].
              uint256 remainder;
              assembly {
                  // Compute remainder using mulmod.
                  remainder := mulmod(x, y, denominator)
  
                  // Subtract 256 bit number from 512 bit number.
                  prod1 := sub(prod1, gt(remainder, prod0))
                  prod0 := sub(prod0, remainder)
              }
  
              // Factor powers of two out of denominator and compute largest power of two divisor of denominator.
              // Always >= 1. See https://cs.stackexchange.com/q/138556/92363.
  
              uint256 twos = denominator & (0 - denominator);
              assembly {
                  // Divide denominator by twos.
                  denominator := div(denominator, twos)
  
                  // Divide [prod1 prod0] by twos.
                  prod0 := div(prod0, twos)
  
                  // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                  twos := add(div(sub(0, twos), twos), 1)
              }
  
              // Shift in bits from prod1 into prod0.
              prod0 |= prod1 * twos;
  
              // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
              // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
              // four bits. That is, denominator * inv = 1 mod 2^4.
              uint256 inverse = (3 * denominator) ^ 2;
  
              // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also
              // works in modular arithmetic, doubling the correct bits in each step.
              inverse *= 2 - denominator * inverse; // inverse mod 2^8
              inverse *= 2 - denominator * inverse; // inverse mod 2^16
              inverse *= 2 - denominator * inverse; // inverse mod 2^32
              inverse *= 2 - denominator * inverse; // inverse mod 2^64
              inverse *= 2 - denominator * inverse; // inverse mod 2^128
              inverse *= 2 - denominator * inverse; // inverse mod 2^256
  
              // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
              // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
              // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
              // is no longer required.
              result = prod0 * inverse;
              return result;
          }
      }
  
      /**
       * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
       */
      function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
          uint256 result = mulDiv(x, y, denominator);
          if (unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0) {
              result += 1;
          }
          return result;
      }
  
      /**
       * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
       * towards zero.
       *
       * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
       */
      function sqrt(uint256 a) internal pure returns (uint256) {
          if (a == 0) {
              return 0;
          }
  
          // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
          //
          // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
          // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
          //
          // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
          // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
          // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
          //
          // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
          uint256 result = 1 << (log2(a) >> 1);
  
          // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
          // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
          // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
          // into the expected uint128 result.
          unchecked {
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              return min(result, a / result);
          }
      }
  
      /**
       * @notice Calculates sqrt(a), following the selected rounding direction.
       */
      function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = sqrt(a);
              return result + (unsignedRoundsUp(rounding) && result * result < a ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 2 of a positive value rounded towards zero.
       * Returns 0 if given 0.
       */
      function log2(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >> 128 > 0) {
                  value >>= 128;
                  result += 128;
              }
              if (value >> 64 > 0) {
                  value >>= 64;
                  result += 64;
              }
              if (value >> 32 > 0) {
                  value >>= 32;
                  result += 32;
              }
              if (value >> 16 > 0) {
                  value >>= 16;
                  result += 16;
              }
              if (value >> 8 > 0) {
                  value >>= 8;
                  result += 8;
              }
              if (value >> 4 > 0) {
                  value >>= 4;
                  result += 4;
              }
              if (value >> 2 > 0) {
                  value >>= 2;
                  result += 2;
              }
              if (value >> 1 > 0) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log2(value);
              return result + (unsignedRoundsUp(rounding) && 1 << result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 10 of a positive value rounded towards zero.
       * Returns 0 if given 0.
       */
      function log10(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >= 10 ** 64) {
                  value /= 10 ** 64;
                  result += 64;
              }
              if (value >= 10 ** 32) {
                  value /= 10 ** 32;
                  result += 32;
              }
              if (value >= 10 ** 16) {
                  value /= 10 ** 16;
                  result += 16;
              }
              if (value >= 10 ** 8) {
                  value /= 10 ** 8;
                  result += 8;
              }
              if (value >= 10 ** 4) {
                  value /= 10 ** 4;
                  result += 4;
              }
              if (value >= 10 ** 2) {
                  value /= 10 ** 2;
                  result += 2;
              }
              if (value >= 10 ** 1) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log10(value);
              return result + (unsignedRoundsUp(rounding) && 10 ** result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 256 of a positive value rounded towards zero.
       * Returns 0 if given 0.
       *
       * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
       */
      function log256(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >> 128 > 0) {
                  value >>= 128;
                  result += 16;
              }
              if (value >> 64 > 0) {
                  value >>= 64;
                  result += 8;
              }
              if (value >> 32 > 0) {
                  value >>= 32;
                  result += 4;
              }
              if (value >> 16 > 0) {
                  value >>= 16;
                  result += 2;
              }
              if (value >> 8 > 0) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log256(value);
              return result + (unsignedRoundsUp(rounding) && 1 << (result << 3) < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
       */
      function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
          return uint8(rounding) % 2 == 1;
      }
  }
  
  // File: @openzeppelin/contracts/utils/Strings.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/Strings.sol)
  
  pragma solidity ^0.8.20;
  
  
  
  /**
   * @dev String operations.
   */
  library Strings {
      bytes16 private constant HEX_DIGITS = "0123456789abcdef";
      uint8 private constant ADDRESS_LENGTH = 20;
  
      /**
       * @dev The `value` string doesn't fit in the specified `length`.
       */
      error StringsInsufficientHexLength(uint256 value, uint256 length);
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` decimal representation.
       */
      function toString(uint256 value) internal pure returns (string memory) {
          unchecked {
              uint256 length = Math.log10(value) + 1;
              string memory buffer = new string(length);
              uint256 ptr;
              /// @solidity memory-safe-assembly
              assembly {
                  ptr := add(buffer, add(32, length))
              }
              while (true) {
                  ptr--;
                  /// @solidity memory-safe-assembly
                  assembly {
                      mstore8(ptr, byte(mod(value, 10), HEX_DIGITS))
                  }
                  value /= 10;
                  if (value == 0) break;
              }
              return buffer;
          }
      }
  
      /**
       * @dev Converts a `int256` to its ASCII `string` decimal representation.
       */
      function toStringSigned(int256 value) internal pure returns (string memory) {
          return string.concat(value < 0 ? "-" : "", toString(SignedMath.abs(value)));
      }
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
       */
      function toHexString(uint256 value) internal pure returns (string memory) {
          unchecked {
              return toHexString(value, Math.log256(value) + 1);
          }
      }
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
       */
      function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
          uint256 localValue = value;
          bytes memory buffer = new bytes(2 * length + 2);
          buffer[0] = "0";
          buffer[1] = "x";
          for (uint256 i = 2 * length + 1; i > 1; --i) {
              buffer[i] = HEX_DIGITS[localValue & 0xf];
              localValue >>= 4;
          }
          if (localValue != 0) {
              revert StringsInsufficientHexLength(value, length);
          }
          return string(buffer);
      }
  
      /**
       * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal
       * representation.
       */
      function toHexString(address addr) internal pure returns (string memory) {
          return toHexString(uint256(uint160(addr)), ADDRESS_LENGTH);
      }
  
      /**
       * @dev Returns true if the two strings are equal.
       */
      function equal(string memory a, string memory b) internal pure returns (bool) {
          return bytes(a).length == bytes(b).length && keccak256(bytes(a)) == keccak256(bytes(b));
      }
  }
  
  // File: @openzeppelin/contracts/utils/cryptography/MessageHashUtils.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/MessageHashUtils.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @dev Signature message hash utilities for producing digests to be consumed by {ECDSA} recovery or signing.
   *
   * The library provides methods for generating a hash of a message that conforms to the
   * https://eips.ethereum.org/EIPS/eip-191[EIP 191] and https://eips.ethereum.org/EIPS/eip-712[EIP 712]
   * specifications.
   */
  library MessageHashUtils {
      /**
       * @dev Returns the keccak256 digest of an EIP-191 signed data with version
       * `0x45` (`personal_sign` messages).
       *
       * The digest is calculated by prefixing a bytes32 `messageHash` with
       * `"\x19Ethereum Signed Message:\n32"` and hashing the result. It corresponds with the
       * hash signed when using the https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`] JSON-RPC method.
       *
       * NOTE: The `messageHash` parameter is intended to be the result of hashing a raw message with
       * keccak256, although any bytes32 value can be safely used because the final digest will
       * be re-hashed.
       *
       * See {ECDSA-recover}.
       */
      function toEthSignedMessageHash(bytes32 messageHash) internal pure returns (bytes32 digest) {
          /// @solidity memory-safe-assembly
          assembly {
              mstore(0x00, "\x19Ethereum Signed Message:\n32") // 32 is the bytes-length of messageHash
              mstore(0x1c, messageHash) // 0x1c (28) is the length of the prefix
              digest := keccak256(0x00, 0x3c) // 0x3c is the length of the prefix (0x1c) + messageHash (0x20)
          }
      }
  
      /**
       * @dev Returns the keccak256 digest of an EIP-191 signed data with version
       * `0x45` (`personal_sign` messages).
       *
       * The digest is calculated by prefixing an arbitrary `message` with
       * `"\x19Ethereum Signed Message:\n" + len(message)` and hashing the result. It corresponds with the
       * hash signed when using the https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`] JSON-RPC method.
       *
       * See {ECDSA-recover}.
       */
      function toEthSignedMessageHash(bytes memory message) internal pure returns (bytes32) {
          return
              keccak256(bytes.concat("\x19Ethereum Signed Message:\n", bytes(Strings.toString(message.length)), message));
      }
  
      /**
       * @dev Returns the keccak256 digest of an EIP-191 signed data with version
       * `0x00` (data with intended validator).
       *
       * The digest is calculated by prefixing an arbitrary `data` with `"\x19\x00"` and the intended
       * `validator` address. Then hashing the result.
       *
       * See {ECDSA-recover}.
       */
      function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
          return keccak256(abi.encodePacked(hex"19_00", validator, data));
      }
  
      /**
       * @dev Returns the keccak256 digest of an EIP-712 typed data (EIP-191 version `0x01`).
       *
       * The digest is calculated from a `domainSeparator` and a `structHash`, by prefixing them with
       * `\x19\x01` and hashing the result. It corresponds to the hash signed by the
       * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] JSON-RPC method as part of EIP-712.
       *
       * See {ECDSA-recover}.
       */
      function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 digest) {
          /// @solidity memory-safe-assembly
          assembly {
              let ptr := mload(0x40)
              mstore(ptr, hex"19_01")
              mstore(add(ptr, 0x02), domainSeparator)
              mstore(add(ptr, 0x22), structHash)
              digest := keccak256(ptr, 0x42)
          }
      }
  }
  
  // File: @openzeppelin/contracts/utils/Context.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @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;
      }
  
      function _contextSuffixLength() internal view virtual returns (uint256) {
          return 0;
      }
  }
  
  // File: @openzeppelin/contracts/access/Ownable.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @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.
   *
   * The initial owner is set to the address provided by the deployer. 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;
  
      /**
       * @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);
      }
  }
  
  // File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/IERC721Receiver.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @title ERC721 token receiver interface
   * @dev Interface for any contract that wants to support safeTransfers
   * from ERC721 asset contracts.
   */
  interface IERC721Receiver {
      /**
       * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
       * by `operator` from `from`, this function is called.
       *
       * It must return its Solidity selector to confirm the token transfer.
       * If any other value is returned or the interface is not implemented by the recipient, the transfer will be
       * reverted.
       *
       * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
       */
      function onERC721Received(
          address operator,
          address from,
          uint256 tokenId,
          bytes calldata data
      ) external returns (bytes4);
  }
  
  // File: @openzeppelin/contracts/utils/introspection/IERC165.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/IERC165.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Interface of the ERC165 standard, as defined in the
   * https://eips.ethereum.org/EIPS/eip-165[EIP].
   *
   * Implementers can declare support of contract interfaces, which can then be
   * queried by others ({ERC165Checker}).
   *
   * For an implementation, see {ERC165}.
   */
  interface IERC165 {
      /**
       * @dev Returns true if this contract implements the interface defined by
       * `interfaceId`. See the corresponding
       * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
       * to learn more about how these ids are created.
       *
       * This function call must use less than 30 000 gas.
       */
      function supportsInterface(bytes4 interfaceId) external view returns (bool);
  }
  
  // File: @openzeppelin/contracts/interfaces/IERC165.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC165.sol)
  
  pragma solidity ^0.8.20;
  
  
  // File: @openzeppelin/contracts/utils/introspection/ERC165.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/ERC165.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @dev Implementation of the {IERC165} interface.
   *
   * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
   * for the additional interface id that will be supported. For example:
   *
   * ```solidity
   * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
   *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
   * }
   * ```
   */
  abstract contract ERC165 is IERC165 {
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId) public view virtual returns (bool) {
          return interfaceId == type(IERC165).interfaceId;
      }
  }
  
  // File: @openzeppelin/contracts/token/ERC721/IERC721.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/IERC721.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @dev Required interface of an ERC721 compliant contract.
   */
  interface IERC721 is IERC165 {
      /**
       * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
       */
      event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
  
      /**
       * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
       */
      event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
  
      /**
       * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
       */
      event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
  
      /**
       * @dev Returns the number of tokens in ``owner``'s account.
       */
      function balanceOf(address owner) external view returns (uint256 balance);
  
      /**
       * @dev Returns the owner of the `tokenId` token.
       *
       * Requirements:
       *
       * - `tokenId` must exist.
       */
      function ownerOf(uint256 tokenId) external view returns (address owner);
  
      /**
       * @dev Safely transfers `tokenId` token from `from` to `to`.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must exist and be owned by `from`.
       * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
       * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon
       *   a safe transfer.
       *
       * Emits a {Transfer} event.
       */
      function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
  
      /**
       * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
       * are aware of the ERC721 protocol to prevent tokens from being forever locked.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must exist and be owned by `from`.
       * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or
       *   {setApprovalForAll}.
       * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon
       *   a safe transfer.
       *
       * Emits a {Transfer} event.
       */
      function safeTransferFrom(address from, address to, uint256 tokenId) external;
  
      /**
       * @dev Transfers `tokenId` token from `from` to `to`.
       *
       * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
       * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
       * understand this adds an external call which potentially creates a reentrancy vulnerability.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `tokenId` token must be owned by `from`.
       * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
       *
       * Emits a {Transfer} event.
       */
      function transferFrom(address from, address to, uint256 tokenId) external;
  
      /**
       * @dev Gives permission to `to` to transfer `tokenId` token to another account.
       * The approval is cleared when the token is transferred.
       *
       * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
       *
       * Requirements:
       *
       * - The caller must own the token or be an approved operator.
       * - `tokenId` must exist.
       *
       * Emits an {Approval} event.
       */
      function approve(address to, uint256 tokenId) external;
  
      /**
       * @dev Approve or remove `operator` as an operator for the caller.
       * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
       *
       * Requirements:
       *
       * - The `operator` cannot be the address zero.
       *
       * Emits an {ApprovalForAll} event.
       */
      function setApprovalForAll(address operator, bool approved) external;
  
      /**
       * @dev Returns the account approved for `tokenId` token.
       *
       * Requirements:
       *
       * - `tokenId` must exist.
       */
      function getApproved(uint256 tokenId) external view returns (address operator);
  
      /**
       * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
       *
       * See {setApprovalForAll}
       */
      function isApprovedForAll(address owner, address operator) external view returns (bool);
  }
  
  // File: @openzeppelin/contracts/interfaces/IERC721.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC721.sol)
  
  pragma solidity ^0.8.20;
  
  
  // File: @openzeppelin/contracts/interfaces/IERC4906.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC4906.sol)
  
  pragma solidity ^0.8.20;
  
  
  
  /// @title EIP-721 Metadata Update Extension
  interface IERC4906 is IERC165, IERC721 {
      /// @dev This event emits when the metadata of a token is changed.
      /// So that the third-party platforms such as NFT market could
      /// timely update the images and related attributes of the NFT.
      event MetadataUpdate(uint256 _tokenId);
  
      /// @dev This event emits when the metadata of a range of tokens is changed.
      /// So that the third-party platforms such as NFT market could
      /// timely update the images and related attributes of the NFTs.
      event BatchMetadataUpdate(uint256 _fromTokenId, uint256 _toTokenId);
  }
  
  // File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/extensions/IERC721Enumerable.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
   * @dev See https://eips.ethereum.org/EIPS/eip-721
   */
  interface IERC721Enumerable is IERC721 {
      /**
       * @dev Returns the total amount of tokens stored by the contract.
       */
      function totalSupply() external view returns (uint256);
  
      /**
       * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
       * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
       */
      function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
  
      /**
       * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
       * Use along with {totalSupply} to enumerate all tokens.
       */
      function tokenByIndex(uint256 index) external view returns (uint256);
  }
  
  // File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/extensions/IERC721Metadata.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
   * @dev See https://eips.ethereum.org/EIPS/eip-721
   */
  interface IERC721Metadata is IERC721 {
      /**
       * @dev Returns the token collection name.
       */
      function name() external view returns (string memory);
  
      /**
       * @dev Returns the token collection symbol.
       */
      function symbol() external view returns (string memory);
  
      /**
       * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
       */
      function tokenURI(uint256 tokenId) external view returns (string memory);
  }
  
  // File: @openzeppelin/contracts/token/ERC721/ERC721.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/ERC721.sol)
  
  pragma solidity ^0.8.20;
  
  
  
  
  
  
  
  
  /**
   * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
   * the Metadata extension, but not including the Enumerable extension, which is available separately as
   * {ERC721Enumerable}.
   */
  abstract contract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Errors {
      using Strings for uint256;
  
      // Token name
      string private _name;
  
      // Token symbol
      string private _symbol;
  
      mapping(uint256 tokenId => address) private _owners;
  
      mapping(address owner => uint256) private _balances;
  
      mapping(uint256 tokenId => address) private _tokenApprovals;
  
      mapping(address owner => mapping(address operator => bool)) private _operatorApprovals;
  
      /**
       * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
       */
      constructor(string memory name_, string memory symbol_) {
          _name = name_;
          _symbol = symbol_;
      }
  
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
          return
              interfaceId == type(IERC721).interfaceId ||
              interfaceId == type(IERC721Metadata).interfaceId ||
              super.supportsInterface(interfaceId);
      }
  
      /**
       * @dev See {IERC721-balanceOf}.
       */
      function balanceOf(address owner) public view virtual returns (uint256) {
          if (owner == address(0)) {
              revert ERC721InvalidOwner(address(0));
          }
          return _balances[owner];
      }
  
      /**
       * @dev See {IERC721-ownerOf}.
       */
      function ownerOf(uint256 tokenId) public view virtual returns (address) {
          return _requireOwned(tokenId);
      }
  
      /**
       * @dev See {IERC721Metadata-name}.
       */
      function name() public view virtual returns (string memory) {
          return _name;
      }
  
      /**
       * @dev See {IERC721Metadata-symbol}.
       */
      function symbol() public view virtual returns (string memory) {
          return _symbol;
      }
  
      /**
       * @dev See {IERC721Metadata-tokenURI}.
       */
      function tokenURI(uint256 tokenId) public view virtual returns (string memory) {
          _requireOwned(tokenId);
  
          string memory baseURI = _baseURI();
          return bytes(baseURI).length > 0 ? string.concat(baseURI, tokenId.toString()) : "";
      }
  
      /**
       * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
       * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
       * by default, can be overridden in child contracts.
       */
      function _baseURI() internal view virtual returns (string memory) {
          return "";
      }
  
      /**
       * @dev See {IERC721-approve}.
       */
      function approve(address to, uint256 tokenId) public virtual {
          _approve(to, tokenId, _msgSender());
      }
  
      /**
       * @dev See {IERC721-getApproved}.
       */
      function getApproved(uint256 tokenId) public view virtual returns (address) {
          _requireOwned(tokenId);
  
          return _getApproved(tokenId);
      }
  
      /**
       * @dev See {IERC721-setApprovalForAll}.
       */
      function setApprovalForAll(address operator, bool approved) public virtual {
          _setApprovalForAll(_msgSender(), operator, approved);
      }
  
      /**
       * @dev See {IERC721-isApprovedForAll}.
       */
      function isApprovedForAll(address owner, address operator) public view virtual returns (bool) {
          return _operatorApprovals[owner][operator];
      }
  
      /**
       * @dev See {IERC721-transferFrom}.
       */
      function transferFrom(address from, address to, uint256 tokenId) public virtual {
          if (to == address(0)) {
              revert ERC721InvalidReceiver(address(0));
          }
          // Setting an "auth" arguments enables the `_isAuthorized` check which verifies that the token exists
          // (from != 0). Therefore, it is not needed to verify that the return value is not 0 here.
          address previousOwner = _update(to, tokenId, _msgSender());
          if (previousOwner != from) {
              revert ERC721IncorrectOwner(from, tokenId, previousOwner);
          }
      }
  
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(address from, address to, uint256 tokenId) public {
          safeTransferFrom(from, to, tokenId, "");
      }
  
      /**
       * @dev See {IERC721-safeTransferFrom}.
       */
      function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public virtual {
          transferFrom(from, to, tokenId);
          _checkOnERC721Received(from, to, tokenId, data);
      }
  
      /**
       * @dev Returns the owner of the `tokenId`. Does NOT revert if token doesn't exist
       *
       * IMPORTANT: Any overrides to this function that add ownership of tokens not tracked by the
       * core ERC721 logic MUST be matched with the use of {_increaseBalance} to keep balances
       * consistent with ownership. The invariant to preserve is that for any address `a` the value returned by
       * `balanceOf(a)` must be equal to the number of tokens such that `_ownerOf(tokenId)` is `a`.
       */
      function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
          return _owners[tokenId];
      }
  
      /**
       * @dev Returns the approved address for `tokenId`. Returns 0 if `tokenId` is not minted.
       */
      function _getApproved(uint256 tokenId) internal view virtual returns (address) {
          return _tokenApprovals[tokenId];
      }
  
      /**
       * @dev Returns whether `spender` is allowed to manage `owner`'s tokens, or `tokenId` in
       * particular (ignoring whether it is owned by `owner`).
       *
       * WARNING: This function assumes that `owner` is the actual owner of `tokenId` and does not verify this
       * assumption.
       */
      function _isAuthorized(address owner, address spender, uint256 tokenId) internal view virtual returns (bool) {
          return
              spender != address(0) &&
              (owner == spender || isApprovedForAll(owner, spender) || _getApproved(tokenId) == spender);
      }
  
      /**
       * @dev Checks if `spender` can operate on `tokenId`, assuming the provided `owner` is the actual owner.
       * Reverts if `spender` does not have approval from the provided `owner` for the given token or for all its assets
       * the `spender` for the specific `tokenId`.
       *
       * WARNING: This function assumes that `owner` is the actual owner of `tokenId` and does not verify this
       * assumption.
       */
      function _checkAuthorized(address owner, address spender, uint256 tokenId) internal view virtual {
          if (!_isAuthorized(owner, spender, tokenId)) {
              if (owner == address(0)) {
                  revert ERC721NonexistentToken(tokenId);
              } else {
                  revert ERC721InsufficientApproval(spender, tokenId);
              }
          }
      }
  
      /**
       * @dev Unsafe write access to the balances, used by extensions that "mint" tokens using an {ownerOf} override.
       *
       * NOTE: the value is limited to type(uint128).max. This protect against _balance overflow. It is unrealistic that
       * a uint256 would ever overflow from increments when these increments are bounded to uint128 values.
       *
       * WARNING: Increasing an account's balance using this function tends to be paired with an override of the
       * {_ownerOf} function to resolve the ownership of the corresponding tokens so that balances and ownership
       * remain consistent with one another.
       */
      function _increaseBalance(address account, uint128 value) internal virtual {
          unchecked {
              _balances[account] += value;
          }
      }
  
      /**
       * @dev Transfers `tokenId` from its current owner to `to`, or alternatively mints (or burns) if the current owner
       * (or `to`) is the zero address. Returns the owner of the `tokenId` before the update.
       *
       * The `auth` argument is optional. If the value passed is non 0, then this function will check that
       * `auth` is either the owner of the token, or approved to operate on the token (by the owner).
       *
       * Emits a {Transfer} event.
       *
       * NOTE: If overriding this function in a way that tracks balances, see also {_increaseBalance}.
       */
      function _update(address to, uint256 tokenId, address auth) internal virtual returns (address) {
          address from = _ownerOf(tokenId);
  
          // Perform (optional) operator check
          if (auth != address(0)) {
              _checkAuthorized(from, auth, tokenId);
          }
  
          // Execute the update
          if (from != address(0)) {
              // Clear approval. No need to re-authorize or emit the Approval event
              _approve(address(0), tokenId, address(0), false);
  
              unchecked {
                  _balances[from] -= 1;
              }
          }
  
          if (to != address(0)) {
              unchecked {
                  _balances[to] += 1;
              }
          }
  
          _owners[tokenId] = to;
  
          emit Transfer(from, to, tokenId);
  
          return from;
      }
  
      /**
       * @dev Mints `tokenId` and transfers it to `to`.
       *
       * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
       *
       * Requirements:
       *
       * - `tokenId` must not exist.
       * - `to` cannot be the zero address.
       *
       * Emits a {Transfer} event.
       */
      function _mint(address to, uint256 tokenId) internal {
          if (to == address(0)) {
              revert ERC721InvalidReceiver(address(0));
          }
          address previousOwner = _update(to, tokenId, address(0));
          if (previousOwner != address(0)) {
              revert ERC721InvalidSender(address(0));
          }
      }
  
      /**
       * @dev Mints `tokenId`, transfers it to `to` and checks for `to` acceptance.
       *
       * Requirements:
       *
       * - `tokenId` must not exist.
       * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
       *
       * Emits a {Transfer} event.
       */
      function _safeMint(address to, uint256 tokenId) internal {
          _safeMint(to, tokenId, "");
      }
  
      /**
       * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
       * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
       */
      function _safeMint(address to, uint256 tokenId, bytes memory data) internal virtual {
          _mint(to, tokenId);
          _checkOnERC721Received(address(0), to, tokenId, data);
      }
  
      /**
       * @dev Destroys `tokenId`.
       * The approval is cleared when the token is burned.
       * This is an internal function that does not check if the sender is authorized to operate on the token.
       *
       * Requirements:
       *
       * - `tokenId` must exist.
       *
       * Emits a {Transfer} event.
       */
      function _burn(uint256 tokenId) internal {
          address previousOwner = _update(address(0), tokenId, address(0));
          if (previousOwner == address(0)) {
              revert ERC721NonexistentToken(tokenId);
          }
      }
  
      /**
       * @dev Transfers `tokenId` from `from` to `to`.
       *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - `tokenId` token must be owned by `from`.
       *
       * Emits a {Transfer} event.
       */
      function _transfer(address from, address to, uint256 tokenId) internal {
          if (to == address(0)) {
              revert ERC721InvalidReceiver(address(0));
          }
          address previousOwner = _update(to, tokenId, address(0));
          if (previousOwner == address(0)) {
              revert ERC721NonexistentToken(tokenId);
          } else if (previousOwner != from) {
              revert ERC721IncorrectOwner(from, tokenId, previousOwner);
          }
      }
  
      /**
       * @dev Safely transfers `tokenId` token from `from` to `to`, checking that contract recipients
       * are aware of the ERC721 standard to prevent tokens from being forever locked.
       *
       * `data` is additional data, it has no specified format and it is sent in call to `to`.
       *
       * This internal function is like {safeTransferFrom} in the sense that it invokes
       * {IERC721Receiver-onERC721Received} on the receiver, and can be used to e.g.
       * implement alternative mechanisms to perform token transfer, such as signature-based.
       *
       * Requirements:
       *
       * - `tokenId` token must exist and be owned by `from`.
       * - `to` cannot be the zero address.
       * - `from` cannot be the zero address.
       * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
       *
       * Emits a {Transfer} event.
       */
      function _safeTransfer(address from, address to, uint256 tokenId) internal {
          _safeTransfer(from, to, tokenId, "");
      }
  
      /**
       * @dev Same as {xref-ERC721-_safeTransfer-address-address-uint256-}[`_safeTransfer`], with an additional `data` parameter which is
       * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
       */
      function _safeTransfer(address from, address to, uint256 tokenId, bytes memory data) internal virtual {
          _transfer(from, to, tokenId);
          _checkOnERC721Received(from, to, tokenId, data);
      }
  
      /**
       * @dev Approve `to` to operate on `tokenId`
       *
       * The `auth` argument is optional. If the value passed is non 0, then this function will check that `auth` is
       * either the owner of the token, or approved to operate on all tokens held by this owner.
       *
       * Emits an {Approval} event.
       *
       * Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
       */
      function _approve(address to, uint256 tokenId, address auth) internal {
          _approve(to, tokenId, auth, true);
      }
  
      /**
       * @dev Variant of `_approve` with an optional flag to enable or disable the {Approval} event. The event is not
       * emitted in the context of transfers.
       */
      function _approve(address to, uint256 tokenId, address auth, bool emitEvent) internal virtual {
          // Avoid reading the owner unless necessary
          if (emitEvent || auth != address(0)) {
              address owner = _requireOwned(tokenId);
  
              // We do not use _isAuthorized because single-token approvals should not be able to call approve
              if (auth != address(0) && owner != auth && !isApprovedForAll(owner, auth)) {
                  revert ERC721InvalidApprover(auth);
              }
  
              if (emitEvent) {
                  emit Approval(owner, to, tokenId);
              }
          }
  
          _tokenApprovals[tokenId] = to;
      }
  
      /**
       * @dev Approve `operator` to operate on all of `owner` tokens
       *
       * Requirements:
       * - operator can't be the address zero.
       *
       * Emits an {ApprovalForAll} event.
       */
      function _setApprovalForAll(address owner, address operator, bool approved) internal virtual {
          if (operator == address(0)) {
              revert ERC721InvalidOperator(operator);
          }
          _operatorApprovals[owner][operator] = approved;
          emit ApprovalForAll(owner, operator, approved);
      }
  
      /**
       * @dev Reverts if the `tokenId` doesn't have a current owner (it hasn't been minted, or it has been burned).
       * Returns the owner.
       *
       * Overrides to ownership logic should be done to {_ownerOf}.
       */
      function _requireOwned(uint256 tokenId) internal view returns (address) {
          address owner = _ownerOf(tokenId);
          if (owner == address(0)) {
              revert ERC721NonexistentToken(tokenId);
          }
          return owner;
      }
  
      /**
       * @dev Private function to invoke {IERC721Receiver-onERC721Received} on a target address. This will revert if the
       * recipient doesn't accept the token transfer. The call is not executed if the target address is not a contract.
       *
       * @param from address representing the previous owner of the given token ID
       * @param to target address that will receive the tokens
       * @param tokenId uint256 ID of the token to be transferred
       * @param data bytes optional data to send along with the call
       */
      function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory data) private {
          if (to.code.length > 0) {
              try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) {
                  if (retval != IERC721Receiver.onERC721Received.selector) {
                      revert ERC721InvalidReceiver(to);
                  }
              } catch (bytes memory reason) {
                  if (reason.length == 0) {
                      revert ERC721InvalidReceiver(to);
                  } else {
                      /// @solidity memory-safe-assembly
                      assembly {
                          revert(add(32, reason), mload(reason))
                      }
                  }
              }
          }
      }
  }
  
  // File: @openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/extensions/ERC721URIStorage.sol)
  
  pragma solidity ^0.8.20;
  
  
  
  
  
  /**
   * @dev ERC721 token with storage based token URI management.
   */
  abstract contract ERC721URIStorage is IERC4906, ERC721 {
      using Strings for uint256;
  
      // Interface ID as defined in ERC-4906. This does not correspond to a traditional interface ID as ERC-4906 only
      // defines events and does not include any external function.
      bytes4 private constant ERC4906_INTERFACE_ID = bytes4(0x49064906);
  
      // Optional mapping for token URIs
      mapping(uint256 tokenId => string) private _tokenURIs;
  
      /**
       * @dev See {IERC165-supportsInterface}
       */
      function supportsInterface(bytes4 interfaceId) public view virtual override(ERC721, IERC165) returns (bool) {
          return interfaceId == ERC4906_INTERFACE_ID || super.supportsInterface(interfaceId);
      }
  
      /**
       * @dev See {IERC721Metadata-tokenURI}.
       */
      function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
          _requireOwned(tokenId);
  
          string memory _tokenURI = _tokenURIs[tokenId];
          string memory base = _baseURI();
  
          // If there is no base URI, return the token URI.
          if (bytes(base).length == 0) {
              return _tokenURI;
          }
          // If both are set, concatenate the baseURI and tokenURI (via string.concat).
          if (bytes(_tokenURI).length > 0) {
              return string.concat(base, _tokenURI);
          }
  
          return super.tokenURI(tokenId);
      }
  
      /**
       * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.
       *
       * Emits {MetadataUpdate}.
       */
      function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
          _tokenURIs[tokenId] = _tokenURI;
          emit MetadataUpdate(tokenId);
      }
  }
  
  // File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/extensions/ERC721Enumerable.sol)
  
  pragma solidity ^0.8.20;
  
  
  
  
  /**
   * @dev This implements an optional extension of {ERC721} defined in the EIP that adds enumerability
   * of all the token ids in the contract as well as all token ids owned by each account.
   *
   * CAUTION: `ERC721` extensions that implement custom `balanceOf` logic, such as `ERC721Consecutive`,
   * interfere with enumerability and should not be used together with `ERC721Enumerable`.
   */
  abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
      mapping(address owner => mapping(uint256 index => uint256)) private _ownedTokens;
      mapping(uint256 tokenId => uint256) private _ownedTokensIndex;
  
      uint256[] private _allTokens;
      mapping(uint256 tokenId => uint256) private _allTokensIndex;
  
      /**
       * @dev An `owner`'s token query was out of bounds for `index`.
       *
       * NOTE: The owner being `address(0)` indicates a global out of bounds index.
       */
      error ERC721OutOfBoundsIndex(address owner, uint256 index);
  
      /**
       * @dev Batch mint is not allowed.
       */
      error ERC721EnumerableForbiddenBatchMint();
  
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
          return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
      }
  
      /**
       * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
       */
      function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual returns (uint256) {
          if (index >= balanceOf(owner)) {
              revert ERC721OutOfBoundsIndex(owner, index);
          }
          return _ownedTokens[owner][index];
      }
  
      /**
       * @dev See {IERC721Enumerable-totalSupply}.
       */
      function totalSupply() public view virtual returns (uint256) {
          return _allTokens.length;
      }
  
      /**
       * @dev See {IERC721Enumerable-tokenByIndex}.
       */
      function tokenByIndex(uint256 index) public view virtual returns (uint256) {
          if (index >= totalSupply()) {
              revert ERC721OutOfBoundsIndex(address(0), index);
          }
          return _allTokens[index];
      }
  
      /**
       * @dev See {ERC721-_update}.
       */
      function _update(address to, uint256 tokenId, address auth) internal virtual override returns (address) {
          address previousOwner = super._update(to, tokenId, auth);
  
          if (previousOwner == address(0)) {
              _addTokenToAllTokensEnumeration(tokenId);
          } else if (previousOwner != to) {
              _removeTokenFromOwnerEnumeration(previousOwner, tokenId);
          }
          if (to == address(0)) {
              _removeTokenFromAllTokensEnumeration(tokenId);
          } else if (previousOwner != to) {
              _addTokenToOwnerEnumeration(to, tokenId);
          }
  
          return previousOwner;
      }
  
      /**
       * @dev Private function to add a token to this extension's ownership-tracking data structures.
       * @param to address representing the new owner of the given token ID
       * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
       */
      function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
          uint256 length = balanceOf(to) - 1;
          _ownedTokens[to][length] = tokenId;
          _ownedTokensIndex[tokenId] = length;
      }
  
      /**
       * @dev Private function to add a token to this extension's token tracking data structures.
       * @param tokenId uint256 ID of the token to be added to the tokens list
       */
      function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
          _allTokensIndex[tokenId] = _allTokens.length;
          _allTokens.push(tokenId);
      }
  
      /**
       * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
       * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
       * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
       * This has O(1) time complexity, but alters the order of the _ownedTokens array.
       * @param from address representing the previous owner of the given token ID
       * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
       */
      function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
          // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
          // then delete the last slot (swap and pop).
  
          uint256 lastTokenIndex = balanceOf(from);
          uint256 tokenIndex = _ownedTokensIndex[tokenId];
  
          // When the token to delete is the last token, the swap operation is unnecessary
          if (tokenIndex != lastTokenIndex) {
              uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
  
              _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
              _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
          }
  
          // This also deletes the contents at the last position of the array
          delete _ownedTokensIndex[tokenId];
          delete _ownedTokens[from][lastTokenIndex];
      }
  
      /**
       * @dev Private function to remove a token from this extension's token tracking data structures.
       * This has O(1) time complexity, but alters the order of the _allTokens array.
       * @param tokenId uint256 ID of the token to be removed from the tokens list
       */
      function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
          // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
          // then delete the last slot (swap and pop).
  
          uint256 lastTokenIndex = _allTokens.length - 1;
          uint256 tokenIndex = _allTokensIndex[tokenId];
  
          // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
          // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
          // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
          uint256 lastTokenId = _allTokens[lastTokenIndex];
  
          _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
          _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
  
          // This also deletes the contents at the last position of the array
          delete _allTokensIndex[tokenId];
          _allTokens.pop();
      }
  
      /**
       * See {ERC721-_increaseBalance}. We need that to account tokens that were minted in batch
       */
      function _increaseBalance(address account, uint128 amount) internal virtual override {
          if (amount > 0) {
              revert ERC721EnumerableForbiddenBatchMint();
          }
          super._increaseBalance(account, amount);
      }
  }
  
  // File: contracts/MetaCraftVnodeEthTest.sol
  
  
  pragma solidity ^0.8.20;
  
  
  
  
  
  
  
  
  
  
  
  
  contract MetaCraftVNode is ERC721, IERC721Receiver,ReentrancyGuard{
      // ERC20 token used for minting NFT
      using ECDSA for bytes32;
      IERC20 public immutable ERC20Token;
      uint256 public immutable tokenDecimals;
      using SafeERC20 for IERC20;
      uint256 public _tokenIds;
      address private immutable owner;
     
      // Mapping to track minted addresses
      mapping(address => bool) public _mintedAddresses;
      //tokenURI
      string public constant nodeTokenURI = "ipfs://QmZ1n7S2UHFmBbiGFzFHYsTJoLwbU29rTDquxPccSNqajg";
      // Price in ERC20 tokens to mint NFT
      uint256 public mintPrice;
      bool public locked = true;
      bool public halted = false;
  
      
      // Optional mapping for token URIs
      //mapping (uint256 => string) private _tokenURIs;
      // address's parent
      mapping (address=>address) public parent;
      // tokenOwner
      mapping (uint256=>address) public tokenOwner;
      mapping (address => NodeInfo) public nodes;
  
      uint256 constant public PRICE_INCREMENT = 1;//500
      uint256 constant public ID_INCREMENT = 5; //500
      uint256 constant public MAX_ID = 50000;
  
      address public publicKey = address(0xEe8b45a0c599e8E6512297f99687BF5FE3359147);
      address payable  public feeAddress = payable(address(0x498d09597e35f00ECaB97f5A10F6369aDde00364));
      // Event emitted when an NFT is minted
  
      event NodeStatusChange(address owner, address parent, uint256  tokenId, string status, uint256 timestamp);
      //event TransactionCreated(address withdrawAddress,  uint256 timestamp, uint256 transactionId);
      //event TransactionCompleted(address withdrawAddress,  uint256 timestamp, uint256 transactionId);
      event TransactionSigned(address by, uint transactionId);
  
      event NodeEvents(
          uint256 timeStamp,
          address eventSender,          
          string  eventName
      );
  
      struct TokenInfo {
          uint256 tokenId;
          address tokenOwner;
          uint256 tokenPrice;
          uint256 mintTimestamp;
      }
      struct NodeInfo {
          address nodeAddress;
          address nodeParent;
          uint256 stakeYears;
          TokenInfo tokenInfo;
      }
      enum TransactionType {
          AddOwner,
          RemoveOwner,
          SetParameter,
          SetSalesAddress
      }
      struct SetTransaction {
          TransactionType txType;
          bytes data;
          uint8 signatureCount;
          uint256 timestamp;
          uint256 readyForExecutionTimestamp; 
          bool executed;
      }
  
      mapping(uint => SetTransaction) private _settransactions;
  
      uint[] private _pendingTransactions;
  
      mapping(uint => mapping(address => bool)) private signatures;
  
  
      modifier notExecuted(uint transactionId) {
          SetTransaction memory transaction = _settransactions[transactionId];
          require(transaction.timestamp > 0, "transaction not exist!");
          require(!_settransactions[transactionId].executed, "Transaction already executed");
          _;
      }
  
      mapping(address => uint8) private _validOwners;
      //mapping ( uint=>mapping(address => uint8)) signatures;
      //mapping (uint => Transaction) private _transactions;
      //uint[] private _pendingTransactions;
      uint256 public constant observationPeriod = 24 hours; //hours
      uint256 public constant maxPendingTime = 96 hours; // hours
  
      uint constant MIN_SIGNATURES = 3;
      address[] public validOwners;
      uint private _transactionIdx;
  
      constructor(
          string memory _name,
          string memory _symbol,
          address _erc20Token,
          uint256 _decimals
          //uint256 _mintPrice
      ) ERC721(_name, _symbol) {
          ERC20Token = IERC20(_erc20Token);
          tokenDecimals = _decimals;
          owner = msg.sender;
         
  
         _validOwners[address(0x486d3D3e599985B00547783E447c2d799d7d2eE5)] = 1;
         _validOwners[address(0x498d09597e35f00ECaB97f5A10F6369aDde00364)] = 1;
         _validOwners[address(0xa1813Fb2A6882E8248CD4d4C789480F50CAf7ca4)] = 1;
  
         validOwners.push(address(0x486d3D3e599985B00547783E447c2d799d7d2eE5));
         validOwners.push(address(0x498d09597e35f00ECaB97f5A10F6369aDde00364));
         validOwners.push(address(0x498d09597e35f00ECaB97f5A10F6369aDde00364));
  
      }
  
      function onERC721Received(address, address, uint256, bytes calldata)
      external 
      override
      pure
      returns(bytes4)
      {
          //tokenOwner[tokenId] = from;
          return this.onERC721Received.selector;
      }
  
      modifier onlySelf() {
          require(msg.sender == address(this), "Unauthorized: can only be called by the contract itself");
          _;
      }
  
      modifier validOwner() {
          require(_validOwners[msg.sender] == 1, "not Authorized Mulsig User !");
          _;
      }
  
      function addOwner(address _owner)
          public 
          {
              
              require(msg.sender==owner,"Only owner can set Parameters");
              require(_validOwners[_owner]!=1,"This Owner Already a Valid Owner!");
              require(_owner != address(0),"Zero Address Error!");
             
              TransactionType txType = TransactionType.AddOwner;
              bytes memory data = abi.encodeWithSelector(this.setOwner.selector, _owner, 1);
              addSetTransaction(txType, data);
              
              emit NodeEvents(block.timestamp,msg.sender, "AddValieOwner");
      }
  
      function removeOwner(address _owner)
          public {
              require(msg.sender==owner,"Only owner can set Parameters");
              require(_validOwners[_owner]==1,"This Owner Not a Valid Owner!");
              require(_owner != address(0),"Zero Address Error!");
              
              TransactionType txType = TransactionType.RemoveOwner;
              bytes memory data = abi.encodeWithSelector(this.setOwner.selector, _owner, 0);
              addSetTransaction(txType, data);
              
             
              emit NodeEvents(block.timestamp,msg.sender, "RemoveValieOwner");
      }
      
     
      function setParameters ( bool isLock_, bool isHalt_)
      public
      {
          require(msg.sender==owner,"Only owner can set Parameters");
         
      
          TransactionType txType = TransactionType.SetParameter;
          bytes memory data = abi.encodeWithSelector(this.setLockHalt.selector, isLock_, isHalt_);
          addSetTransaction(txType, data);
  
          emit NodeEvents(block.timestamp,msg.sender, "setParamters");
      }
  
      function setSalesAddress ( address _feeAddress)
      public
      {
          require(msg.sender==owner,"Only owner can set Parameters");
         
          //deleteMaxPendingTx();
          TransactionType txType = TransactionType.SetSalesAddress;
          bytes memory data = abi.encodeWithSelector(this.setFeeAddress.selector, _feeAddress);
          addSetTransaction(txType, data);
  
          emit NodeEvents(block.timestamp,msg.sender, "setSalesAddress");
      }
  
     function isValidFunctionSelector(TransactionType _type, bytes4 selector) private pure returns (bool) {
          if (_type == TransactionType.AddOwner && selector == this.setOwner.selector) return true;
          if (_type == TransactionType.RemoveOwner && selector == this.setOwner.selector) return true;
          if (_type == TransactionType.SetParameter && selector == this.setLockHalt.selector) return true;
          if (_type == TransactionType.SetSalesAddress && selector == this.setFeeAddress.selector) return true;
          return false;
      }
      function  deleteMaxPendingTx()
  
      private 
      {
           require(_pendingTransactions.length <= 1,"has pending txs! Please sign them first");   
           
           if(_pendingTransactions.length == 1 ){
                  uint txId = _pendingTransactions[0];
                  
                  SetTransaction storage pendingsetTx = _settransactions[txId];
                                 
                  //for set param Txs
                  if (pendingsetTx.timestamp > 0 ){
                      if (block.timestamp - pendingsetTx.timestamp > maxPendingTime){
                          deleteSetTx(txId);
                      }else revert("has pending txs yet! Please sign them first"); 
                  }
  
              }
      }
  
      function setOwner(address _owner, uint8 _status) public onlySelf {
          _validOwners[_owner] = _status;
  
          if(_status == 0){
               uint256 ownerLength = validOwners.length;
              for (uint256 i = 0; i < ownerLength; i++) {
                  if (validOwners[i] == _owner) { 
                      validOwners[i] = validOwners[ownerLength - 1];
                      validOwners.pop();
                      break;
                  }
              }
          }else if(_status == 1) {
              validOwners.push(_owner);
          }
          
      }
      function setLockHalt(bool isLock_, bool isHalt_ ) public onlySelf{
          locked=isLock_;
          halted = isHalt_;
      }
      function setFeeAddress(address _feeAddress) public onlySelf{
          feeAddress = payable(_feeAddress);
      }
  
      function addSetTransaction(TransactionType _type, bytes memory _data) private {
          require(msg.sender == owner,"Only owner can set Parameters");
          require(_data.length >= 4, "Data too short for a valid function selector");
          require(isValidFunctionSelector(_type, bytes4(_data)), "Invalid function selector for transaction type");
          
          deleteMaxPendingTx();
  
          uint256 transactionId = _transactionIdx++;
  
          _settransactions[transactionId] = SetTransaction({
              txType: _type,
              data: _data,
              signatureCount: 0,
              timestamp: block.timestamp,
              readyForExecutionTimestamp:block.timestamp,
              executed: false
          });
          _pendingTransactions.push(transactionId);
          
      }
      // Function for authorized owners to sign pending transactions
      function signSetTransaction(uint transactionId) public validOwner notExecuted(transactionId) {
          SetTransaction memory transaction = _settransactions[transactionId];
          require(transaction.timestamp > 0, "transaction not exist!");
          require(!transaction.executed, "Transaction already executed");
  
          require(!signatures[transactionId][msg.sender], "Signature already provided");
  
          if (transaction.txType == TransactionType.SetSalesAddress){
             require(block.timestamp - transaction.timestamp >= 24 hours,"Time Lockin for 24 Hours for each signers !"); //hours
          }
  
          signatures[transactionId][msg.sender] = true;
          _settransactions[transactionId].signatureCount++;
          _settransactions[transactionId].timestamp = block.timestamp;
          uint ownerCount =  validOwners.length;
          uint signCount = ownerCount>=3?MIN_SIGNATURES:ownerCount;
          if (_settransactions[transactionId].signatureCount == signCount) {
                  if (transaction.txType == TransactionType.SetSalesAddress){
                _settransactions[transactionId].readyForExecutionTimestamp = block.timestamp + observationPeriod;  
             }
             else{
                _settransactions[transactionId].readyForExecutionTimestamp = block.timestamp;
                executeSetTransaction(transactionId);
             }
              
          }
          emit TransactionSigned(msg.sender, transactionId);
  
      }
  
     function executeSetTransaction(uint transactionId) 
      validOwner
      public  {
          SetTransaction storage transaction = _settransactions[transactionId];
          require(transaction.signatureCount >= MIN_SIGNATURES,"Signs Not Satisfied");
          require(transaction.readyForExecutionTimestamp>0,"Transaction is not ready for execution");
          require(block.timestamp >= transaction.readyForExecutionTimestamp, "Transaction is not ready for execution");
  
          (bool success,) = address(this).call(transaction.data);
          require(success, "Transaction execution failed");
  
          transaction.executed = true;
          deleteSetTx(transactionId);
      }
  
      function deleteSetTx(uint transactionId)
          
          private {
              SetTransaction memory transaction = _settransactions[transactionId];
              require(transaction.timestamp > 0, "transaction not exist!");
             
              uint256 txLength = _pendingTransactions.length;
              for (uint256 i = 0; i < txLength; i++) {
                  if (_pendingTransactions[i] == transactionId) {
                      
                      _pendingTransactions[i] = _pendingTransactions[txLength - 1];
                     
                      _pendingTransactions.pop();
                      break;
                  }
              }
              delete _settransactions[transactionId];
      }
  
      function getPendingTransactions()
        view
        public
        returns (uint[] memory) {
        return _pendingTransactions;
      }
      function getPendingTransaction(uint transactionId)
        view
        public
        returns ( SetTransaction memory) {
          //Transaction storage pendingwithdrawTx = _transactions[transactionId];
          SetTransaction memory pendingsetTx = _settransactions[transactionId];
          return pendingsetTx;
      }
      function  getValidOwner(address _owner)  view public returns (uint,address[] memory){
  
          return (_validOwners[_owner],validOwners);
      }
  
      
      /*****************************************************/
  
  
      function tokenURI(uint256 tokenId) public view virtual 
      override(ERC721) 
      returns (string memory) {
          require(tokenId <= _tokenIds, "ERC721Metadata: URI query for nonexistent token");
  
          // string memory _tokenURI = _tokenURIs[tokenId];
         
          return nodeTokenURI;
          
      }
  
      function buyNode(
          uint256 timestamp,
          bytes32 nonce,
          //bytes32 message,
          bytes calldata signature,
          address parentAddress,
          uint256 maxPrice,
          uint256 stakeYear
      ) 
      nonReentrant 
      notContract
      external  
      returns (uint256){
          require(!halted, "Node Halted!");
          
          bytes32 challenge = getChallenge(timestamp, nonce, parentAddress, msg.sender);
          //require(message == challenge,"message not correct!");
          bool isVerified = verified(publicKey,challenge, signature);
          require(isVerified, "Verify Error!");
          //require(_to == msg.sender, "User Address Error!");
          require(!_mintedAddresses[msg.sender], "Address already minted an NFT");
          if(parentAddress!=address(0)){
              require(_mintedAddresses[parentAddress],"parent Not Minted Already");
              if(parent[msg.sender]==address(0)) parent[msg.sender] = parentAddress;
              else require(parent[msg.sender] == parentAddress, "parentAddress Error!");
          }else if(parentAddress==address(0)){
              parent[msg.sender] = address(0);
          }
          
          
          uint256 newItemId =++_tokenIds;
  
          mintPrice = calculatePrice(newItemId);
          require(mintPrice <= maxPrice, "price overflow");
          
          ERC20Token.safeTransferFrom(msg.sender, feeAddress, mintPrice);
  
          _mint(address(this), newItemId);
          
          tokenOwner[newItemId] = msg.sender;
  
          _mintedAddresses[msg.sender]=true;
          
          TokenInfo memory token = TokenInfo({
              tokenId: newItemId,
              tokenOwner: msg.sender,
              tokenPrice: mintPrice,
              mintTimestamp: block.timestamp
          });
          NodeInfo memory node = NodeInfo({
              nodeAddress:msg.sender,
              nodeParent: parent[msg.sender],
              stakeYears: stakeYear,
              tokenInfo: token
          });
  
          nodes[msg.sender] = node;
  
          emit NodeStatusChange(msg.sender,parent[msg.sender],newItemId, "Mint", block.timestamp);    
  
          return newItemId;
      }
  
  
      function userFetchToken(
          uint256 tokenId,
          address receiver
      )
      public 
      nonReentrant 
      notContract
      {
          require(tokenOwner[tokenId]== msg.sender,"Token Owner not Correct!");
          //require(tokenOwner[tokenId] == receiver, "Token receiver not Correct!");
          require(!locked, "Token Can not be fetch currently!");
          ERC721(this).safeTransferFrom(address(this), receiver, tokenId);
          emit NodeStatusChange(msg.sender,parent[msg.sender],tokenId, "Fetch", block.timestamp);    
      }
  
  
      function getTokenOwner(uint256 tokenId) public view returns (address) {
          return tokenOwner[tokenId];
      }
      function ownerOf(uint256 tokenId) public override view returns (address) {
          address currentOwner = super.ownerOf(tokenId);
          if(currentOwner == address(this)) return tokenOwner[tokenId];
          else return super.ownerOf(tokenId);
      }
      
      function getAddressInfo(address userAddress) public view returns(NodeInfo memory  ){
          return nodes[userAddress];
      }
      function AddressMinted(address userAddress) public view returns ( bool) {
          return _mintedAddresses[userAddress];
      }
  
      function getNodesInfo()public view returns(uint256,uint256,uint256,uint256)
      {
          uint256 currentTokenId = _tokenIds;
          uint256 nextPrice = calculatePrice(currentTokenId+1);
          return (nextPrice, currentTokenId+1, currentTokenId,mintPrice);
      }
      function uint256ToString(uint256 value) public pure returns (string memory) {
              if (value == 0) {
                  return "0";
              }
              uint256 temp = value;
              uint256 digits;
              while (temp != 0) {
                  temp /= 10;
                  digits++;
              }
              bytes memory buffer = new bytes(digits);
              while (value != 0) {
                  digits -= 1;
                  buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                  value /= 10;
              }
              return string(buffer);
      }
       //get Challenge
      function getChallenge(uint256 timestamp,
                                bytes32 nonce, 
                              address parentAddress,
                                address userAddress
                               ) public pure returns (bytes32){
          
          bytes32 challenge = keccak256(abi.encodePacked( userAddress, timestamp, nonce, parentAddress));
         
          return challenge;   
      }
       function verified(
          address expectedSigner,
          bytes32 messageHash,
          bytes memory signature
      ) public pure returns (bool) {
          // Compute the message hash that was originally signed, prefixed according to the Ethereum standard.
          bytes32 ethSignedMessageHash = MessageHashUtils.toEthSignedMessageHash(messageHash);
          //bytes32 ethSignedMessageHash = getEthSignedMessageHash(messageHash);
          
          // Recover the signer address from the signature using the ECDSA library.
          address recoveredSigner = ethSignedMessageHash.recover(signature);
  
          // Return true if the recovered signer matches the expected signer, otherwise false.
          return (recoveredSigner == expectedSigner);
      }
  
     
      function getEthSignedMessageHash(bytes32 _messageHash) private  pure returns (bytes32) {
        
          return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", _messageHash));
      }
  
  
      //not contract address
      modifier notContract() {
      require((!_isContract(msg.sender)) && (msg.sender == tx.origin), "contract not allowed");
      _;
      }
  
      function _isContract(address addr) internal view returns (bool) {
          uint256 size;
          assembly {
              size := extcodesize(addr)
          }
          return size > 0;
      }
  
      function calculatePrice(uint256 id) public view   returns (uint256) {
        
          require(id<= MAX_ID,"ID exceeds maximum limit");
  
          uint256 priceLevel = ((id-1) / ID_INCREMENT) + 1;
          return priceLevel * PRICE_INCREMENT * 10** tokenDecimals ;
         
      }
         
  }