ETH Price: $2,178.87 (-9.87%)

Transaction Decoder

Block:
18563090 at Nov-13-2023 12:49:59 PM +UTC
Transaction Fee:
0.002301633971694458 ETH $5.01
Gas Used:
60,479 Gas / 38.056746502 Gwei

Emitted Events:

363 MeldBankSignup.BankSignupCodeRedeemed( code=0AA6468E8224AEC5623073CB83BA0449049D5A1AAE03211AF0A75DB0EBF65589, userAddress=[Sender] 0x9c614af87740b110a9e428fbcb93b49c4db61a40 )

Account State Difference:

  Address   Before After State Difference Code
1.900616875582664754 Eth1.90062247722288063 Eth0.000005601640215876
0x33300033...3e23e1BB0
0x9C614AF8...C4Db61A40
0.01605725087761018 Eth
Nonce: 76
0.013155616905915722 Eth
Nonce: 77
0.002901633971694458
0xdada7C9c...6867cDa8B 1.011323940317703439 Eth1.011923940317703439 Eth0.0006

Execution Trace

ETH 0.0006 MeldBankSignup.redeemCodeNative( _code=0AA6468E8224AEC5623073CB83BA0449049D5A1AAE03211AF0A75DB0EBF65589 )
  • ETH 0.0006 0xdada7c9cf46b95e68800bced46b9aaf6867cda8b.CALL( )
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.8.0) (access/AccessControl.sol)
    pragma solidity ^0.8.0;
    import "./IAccessControl.sol";
    import "../utils/Context.sol";
    import "../utils/Strings.sol";
    import "../utils/introspection/ERC165.sol";
    /**
     * @dev Contract module that allows children to implement role-based access
     * control mechanisms. This is a lightweight version that doesn't allow enumerating role
     * members except through off-chain means by accessing the contract event logs. Some
     * applications may benefit from on-chain enumerability, for those cases see
     * {AccessControlEnumerable}.
     *
     * Roles are referred to by their `bytes32` identifier. These should be exposed
     * in the external API and be unique. The best way to achieve this is by
     * using `public constant` hash digests:
     *
     * ```
     * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
     * ```
     *
     * Roles can be used to represent a set of permissions. To restrict access to a
     * function call, use {hasRole}:
     *
     * ```
     * function foo() public {
     *     require(hasRole(MY_ROLE, msg.sender));
     *     ...
     * }
     * ```
     *
     * Roles can be granted and revoked dynamically via the {grantRole} and
     * {revokeRole} functions. Each role has an associated admin role, and only
     * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
     *
     * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
     * that only accounts with this role will be able to grant or revoke other
     * roles. More complex role relationships can be created by using
     * {_setRoleAdmin}.
     *
     * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
     * grant and revoke this role. Extra precautions should be taken to secure
     * accounts that have been granted it.
     */
    abstract contract AccessControl is Context, IAccessControl, ERC165 {
        struct RoleData {
            mapping(address => bool) members;
            bytes32 adminRole;
        }
        mapping(bytes32 => RoleData) private _roles;
        bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
        /**
         * @dev Modifier that checks that an account has a specific role. Reverts
         * with a standardized message including the required role.
         *
         * The format of the revert reason is given by the following regular expression:
         *
         *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
         *
         * _Available since v4.1._
         */
        modifier onlyRole(bytes32 role) {
            _checkRole(role);
            _;
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
        }
        /**
         * @dev Returns `true` if `account` has been granted `role`.
         */
        function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
            return _roles[role].members[account];
        }
        /**
         * @dev Revert with a standard message if `_msgSender()` is missing `role`.
         * Overriding this function changes the behavior of the {onlyRole} modifier.
         *
         * Format of the revert message is described in {_checkRole}.
         *
         * _Available since v4.6._
         */
        function _checkRole(bytes32 role) internal view virtual {
            _checkRole(role, _msgSender());
        }
        /**
         * @dev Revert with a standard message if `account` is missing `role`.
         *
         * The format of the revert reason is given by the following regular expression:
         *
         *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
         */
        function _checkRole(bytes32 role, address account) internal view virtual {
            if (!hasRole(role, account)) {
                revert(
                    string(
                        abi.encodePacked(
                            "AccessControl: account ",
                            Strings.toHexString(account),
                            " is missing role ",
                            Strings.toHexString(uint256(role), 32)
                        )
                    )
                );
            }
        }
        /**
         * @dev Returns the admin role that controls `role`. See {grantRole} and
         * {revokeRole}.
         *
         * To change a role's admin, use {_setRoleAdmin}.
         */
        function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
            return _roles[role].adminRole;
        }
        /**
         * @dev Grants `role` to `account`.
         *
         * If `account` had not been already granted `role`, emits a {RoleGranted}
         * event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         *
         * May emit a {RoleGranted} event.
         */
        function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
            _grantRole(role, account);
        }
        /**
         * @dev Revokes `role` from `account`.
         *
         * If `account` had been granted `role`, emits a {RoleRevoked} event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         *
         * May emit a {RoleRevoked} event.
         */
        function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
            _revokeRole(role, account);
        }
        /**
         * @dev Revokes `role` from the calling account.
         *
         * Roles are often managed via {grantRole} and {revokeRole}: this function's
         * purpose is to provide a mechanism for accounts to lose their privileges
         * if they are compromised (such as when a trusted device is misplaced).
         *
         * If the calling account had been revoked `role`, emits a {RoleRevoked}
         * event.
         *
         * Requirements:
         *
         * - the caller must be `account`.
         *
         * May emit a {RoleRevoked} event.
         */
        function renounceRole(bytes32 role, address account) public virtual override {
            require(account == _msgSender(), "AccessControl: can only renounce roles for self");
            _revokeRole(role, account);
        }
        /**
         * @dev Grants `role` to `account`.
         *
         * If `account` had not been already granted `role`, emits a {RoleGranted}
         * event. Note that unlike {grantRole}, this function doesn't perform any
         * checks on the calling account.
         *
         * May emit a {RoleGranted} event.
         *
         * [WARNING]
         * ====
         * This function should only be called from the constructor when setting
         * up the initial roles for the system.
         *
         * Using this function in any other way is effectively circumventing the admin
         * system imposed by {AccessControl}.
         * ====
         *
         * NOTE: This function is deprecated in favor of {_grantRole}.
         */
        function _setupRole(bytes32 role, address account) internal virtual {
            _grantRole(role, account);
        }
        /**
         * @dev Sets `adminRole` as ``role``'s admin role.
         *
         * Emits a {RoleAdminChanged} event.
         */
        function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
            bytes32 previousAdminRole = getRoleAdmin(role);
            _roles[role].adminRole = adminRole;
            emit RoleAdminChanged(role, previousAdminRole, adminRole);
        }
        /**
         * @dev Grants `role` to `account`.
         *
         * Internal function without access restriction.
         *
         * May emit a {RoleGranted} event.
         */
        function _grantRole(bytes32 role, address account) internal virtual {
            if (!hasRole(role, account)) {
                _roles[role].members[account] = true;
                emit RoleGranted(role, account, _msgSender());
            }
        }
        /**
         * @dev Revokes `role` from `account`.
         *
         * Internal function without access restriction.
         *
         * May emit a {RoleRevoked} event.
         */
        function _revokeRole(bytes32 role, address account) internal virtual {
            if (hasRole(role, account)) {
                _roles[role].members[account] = false;
                emit RoleRevoked(role, account, _msgSender());
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev External interface of AccessControl declared to support ERC165 detection.
     */
    interface IAccessControl {
        /**
         * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
         *
         * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
         * {RoleAdminChanged} not being emitted signaling this.
         *
         * _Available since v3.1._
         */
        event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
        /**
         * @dev Emitted when `account` is granted `role`.
         *
         * `sender` is the account that originated the contract call, an admin role
         * bearer except when using {AccessControl-_setupRole}.
         */
        event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
        /**
         * @dev Emitted when `account` is revoked `role`.
         *
         * `sender` is the account that originated the contract call:
         *   - if using `revokeRole`, it is the admin role bearer
         *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
         */
        event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
        /**
         * @dev Returns `true` if `account` has been granted `role`.
         */
        function hasRole(bytes32 role, address account) external view returns (bool);
        /**
         * @dev Returns the admin role that controls `role`. See {grantRole} and
         * {revokeRole}.
         *
         * To change a role's admin, use {AccessControl-_setRoleAdmin}.
         */
        function getRoleAdmin(bytes32 role) external view returns (bytes32);
        /**
         * @dev Grants `role` to `account`.
         *
         * If `account` had not been already granted `role`, emits a {RoleGranted}
         * event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function grantRole(bytes32 role, address account) external;
        /**
         * @dev Revokes `role` from `account`.
         *
         * If `account` had been granted `role`, emits a {RoleRevoked} event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function revokeRole(bytes32 role, address account) external;
        /**
         * @dev Revokes `role` from the calling account.
         *
         * Roles are often managed via {grantRole} and {revokeRole}: this function's
         * purpose is to provide a mechanism for accounts to lose their privileges
         * if they are compromised (such as when a trusted device is misplaced).
         *
         * If the calling account had been granted `role`, emits a {RoleRevoked}
         * event.
         *
         * Requirements:
         *
         * - the caller must be `account`.
         */
        function renounceRole(bytes32 role, address account) external;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
     * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
     *
     * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
     * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
     * need to send a transaction, and thus is not required to hold Ether at all.
     */
    interface IERC20Permit {
        /**
         * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
         * given ``owner``'s signed approval.
         *
         * IMPORTANT: The same issues {IERC20-approve} has related to transaction
         * ordering also apply here.
         *
         * Emits an {Approval} event.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         * - `deadline` must be a timestamp in the future.
         * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
         * over the EIP712-formatted function arguments.
         * - the signature must use ``owner``'s current nonce (see {nonces}).
         *
         * For more information on the signature format, see the
         * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
         * section].
         */
        function permit(
            address owner,
            address spender,
            uint256 value,
            uint256 deadline,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) external;
        /**
         * @dev Returns the current nonce for `owner`. This value must be
         * included whenever a signature is generated for {permit}.
         *
         * Every successful call to {permit} increases ``owner``'s nonce by one. This
         * prevents a signature from being used multiple times.
         */
        function nonces(address owner) external view returns (uint256);
        /**
         * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
         */
        // solhint-disable-next-line func-name-mixedcase
        function DOMAIN_SEPARATOR() external view returns (bytes32);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP.
     */
    interface IERC20 {
        /**
         * @dev Emitted when `value` tokens are moved from one account (`from`) to
         * another (`to`).
         *
         * Note that `value` may be zero.
         */
        event Transfer(address indexed from, address indexed to, uint256 value);
        /**
         * @dev Emitted when the allowance of a `spender` for an `owner` is set by
         * a call to {approve}. `value` is the new allowance.
         */
        event Approval(address indexed owner, address indexed spender, uint256 value);
        /**
         * @dev Returns the amount of tokens in existence.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns the amount of tokens owned by `account`.
         */
        function balanceOf(address account) external view returns (uint256);
        /**
         * @dev Moves `amount` tokens from the caller's account to `to`.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transfer(address to, uint256 amount) external returns (bool);
        /**
         * @dev Returns the remaining number of tokens that `spender` will be
         * allowed to spend on behalf of `owner` through {transferFrom}. This is
         * zero by default.
         *
         * This value changes when {approve} or {transferFrom} are called.
         */
        function allowance(address owner, address spender) external view returns (uint256);
        /**
         * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * IMPORTANT: Beware that changing an allowance with this method brings the risk
         * that someone may use both the old and the new allowance by unfortunate
         * transaction ordering. One possible solution to mitigate this race
         * condition is to first reduce the spender's allowance to 0 and set the
         * desired value afterwards:
         * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
         *
         * Emits an {Approval} event.
         */
        function approve(address spender, uint256 amount) external returns (bool);
        /**
         * @dev Moves `amount` tokens from `from` to `to` using the
         * allowance mechanism. `amount` is then deducted from the caller's
         * allowance.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(
            address from,
            address to,
            uint256 amount
        ) external returns (bool);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)
    pragma solidity ^0.8.0;
    import "../IERC20.sol";
    import "../extensions/draft-IERC20Permit.sol";
    import "../../../utils/Address.sol";
    /**
     * @title SafeERC20
     * @dev Wrappers around ERC20 operations that throw on failure (when the token
     * contract returns false). Tokens that return no value (and instead revert or
     * throw on failure) are also supported, non-reverting calls are assumed to be
     * successful.
     * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
     * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
     */
    library SafeERC20 {
        using Address for address;
        function safeTransfer(
            IERC20 token,
            address to,
            uint256 value
        ) internal {
            _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
        }
        function safeTransferFrom(
            IERC20 token,
            address from,
            address to,
            uint256 value
        ) internal {
            _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
        }
        /**
         * @dev Deprecated. This function has issues similar to the ones found in
         * {IERC20-approve}, and its usage is discouraged.
         *
         * Whenever possible, use {safeIncreaseAllowance} and
         * {safeDecreaseAllowance} instead.
         */
        function safeApprove(
            IERC20 token,
            address spender,
            uint256 value
        ) internal {
            // safeApprove should only be called when setting an initial allowance,
            // or when resetting it to zero. To increase and decrease it, use
            // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
            require(
                (value == 0) || (token.allowance(address(this), spender) == 0),
                "SafeERC20: approve from non-zero to non-zero allowance"
            );
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
        }
        function safeIncreaseAllowance(
            IERC20 token,
            address spender,
            uint256 value
        ) internal {
            uint256 newAllowance = token.allowance(address(this), spender) + value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
        function safeDecreaseAllowance(
            IERC20 token,
            address spender,
            uint256 value
        ) internal {
            unchecked {
                uint256 oldAllowance = token.allowance(address(this), spender);
                require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                uint256 newAllowance = oldAllowance - value;
                _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
            }
        }
        function safePermit(
            IERC20Permit token,
            address owner,
            address spender,
            uint256 value,
            uint256 deadline,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal {
            uint256 nonceBefore = token.nonces(owner);
            token.permit(owner, spender, value, deadline, v, r, s);
            uint256 nonceAfter = token.nonces(owner);
            require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
        }
        /**
         * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
         * on the return value: the return value is optional (but if data is returned, it must not be false).
         * @param token The token targeted by the call.
         * @param data The call data (encoded using abi.encode or one of its variants).
         */
        function _callOptionalReturn(IERC20 token, bytes memory data) private {
            // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
            // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
            // the target address contains contract code and also asserts for success in the low-level call.
            bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
            if (returndata.length > 0) {
                // Return data is optional
                require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
    pragma solidity ^0.8.1;
    /**
     * @dev Collection of functions related to the address type
     */
    library Address {
        /**
         * @dev Returns true if `account` is a contract.
         *
         * [IMPORTANT]
         * ====
         * It is unsafe to assume that an address for which this function returns
         * false is an externally-owned account (EOA) and not a contract.
         *
         * Among others, `isContract` will return false for the following
         * types of addresses:
         *
         *  - an externally-owned account
         *  - a contract in construction
         *  - an address where a contract will be created
         *  - an address where a contract lived, but was destroyed
         * ====
         *
         * [IMPORTANT]
         * ====
         * You shouldn't rely on `isContract` to protect against flash loan attacks!
         *
         * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
         * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
         * constructor.
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize/address.code.length, which returns 0
            // for contracts in construction, since the code is only stored at the end
            // of the constructor execution.
            return account.code.length > 0;
        }
        /**
         * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
         * `recipient`, forwarding all available gas and reverting on errors.
         *
         * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
         * of certain opcodes, possibly making contracts go over the 2300 gas limit
         * imposed by `transfer`, making them unable to receive funds via
         * `transfer`. {sendValue} removes this limitation.
         *
         * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
         *
         * IMPORTANT: because control is transferred to `recipient`, care must be
         * taken to not create reentrancy vulnerabilities. Consider using
         * {ReentrancyGuard} or the
         * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
         */
        function sendValue(address payable recipient, uint256 amount) internal {
            require(address(this).balance >= amount, "Address: insufficient balance");
            (bool success, ) = recipient.call{value: amount}("");
            require(success, "Address: unable to send value, recipient may have reverted");
        }
        /**
         * @dev Performs a Solidity function call using a low level `call`. A
         * plain `call` is an unsafe replacement for a function call: use this
         * function instead.
         *
         * If `target` reverts with a revert reason, it is bubbled up by this
         * function (like regular Solidity function calls).
         *
         * Returns the raw returned data. To convert to the expected return value,
         * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
         *
         * Requirements:
         *
         * - `target` must be a contract.
         * - calling `target` with `data` must not revert.
         *
         * _Available since v3.1._
         */
        function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionCallWithValue(target, data, 0, "Address: low-level call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
         * `errorMessage` as a fallback revert reason when `target` reverts.
         *
         * _Available since v3.1._
         */
        function functionCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal returns (bytes memory) {
            return functionCallWithValue(target, data, 0, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but also transferring `value` wei to `target`.
         *
         * Requirements:
         *
         * - the calling contract must have an ETH balance of at least `value`.
         * - the called Solidity function must be `payable`.
         *
         * _Available since v3.1._
         */
        function functionCallWithValue(
            address target,
            bytes memory data,
            uint256 value
        ) internal returns (bytes memory) {
            return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
        }
        /**
         * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
         * with `errorMessage` as a fallback revert reason when `target` reverts.
         *
         * _Available since v3.1._
         */
        function functionCallWithValue(
            address target,
            bytes memory data,
            uint256 value,
            string memory errorMessage
        ) internal returns (bytes memory) {
            require(address(this).balance >= value, "Address: insufficient balance for call");
            (bool success, bytes memory returndata) = target.call{value: value}(data);
            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a static call.
         *
         * _Available since v3.3._
         */
        function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
            return functionStaticCall(target, data, "Address: low-level static call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
         * but performing a static call.
         *
         * _Available since v3.3._
         */
        function functionStaticCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal view returns (bytes memory) {
            (bool success, bytes memory returndata) = target.staticcall(data);
            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionDelegateCall(target, data, "Address: low-level delegate call failed");
        }
        /**
         * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
         * but performing a delegate call.
         *
         * _Available since v3.4._
         */
        function functionDelegateCall(
            address target,
            bytes memory data,
            string memory errorMessage
        ) internal returns (bytes memory) {
            (bool success, bytes memory returndata) = target.delegatecall(data);
            return verifyCallResultFromTarget(target, success, returndata, errorMessage);
        }
        /**
         * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
         * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
         *
         * _Available since v4.8._
         */
        function verifyCallResultFromTarget(
            address target,
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal view returns (bytes memory) {
            if (success) {
                if (returndata.length == 0) {
                    // only check isContract if the call was successful and the return data is empty
                    // otherwise we already know that it was a contract
                    require(isContract(target), "Address: call to non-contract");
                }
                return returndata;
            } else {
                _revert(returndata, errorMessage);
            }
        }
        /**
         * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
         * revert reason or using the provided one.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal pure returns (bytes memory) {
            if (success) {
                return returndata;
            } else {
                _revert(returndata, errorMessage);
            }
        }
        function _revert(bytes memory returndata, string memory errorMessage) private pure {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Provides information about the current execution context, including the
     * sender of the transaction and its data. While these are generally available
     * via msg.sender and msg.data, they should not be accessed in such a direct
     * manner, since when dealing with meta-transactions the account sending and
     * paying for execution may not be the actual sender (as far as an application
     * is concerned).
     *
     * This contract is only required for intermediate, library-like contracts.
     */
    abstract contract Context {
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
    pragma solidity ^0.8.0;
    import "./IERC165.sol";
    /**
     * @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);
     * }
     * ```
     *
     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
     */
    abstract contract ERC165 is IERC165 {
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165).interfaceId;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
    pragma solidity ^0.8.0;
    /**
     * @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);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Standard math utilities missing in the Solidity language.
     */
    library Math {
        enum Rounding {
            Down, // Toward negative infinity
            Up, // Toward infinity
            Zero // Toward zero
        }
        /**
         * @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 up instead
         * of rounding down.
         */
        function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
            // (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; // Least significant 256 bits of the product
                uint256 prod1; // Most significant 256 bits of the product
                assembly {
                    let mm := mulmod(x, y, not(0))
                    prod0 := mul(x, y)
                    prod1 := sub(sub(mm, prod0), lt(mm, prod0))
                }
                // Handle non-overflow cases, 256 by 256 division.
                if (prod1 == 0) {
                    return prod0 / denominator;
                }
                // Make sure the result is less than 2^256. Also prevents denominator == 0.
                require(denominator > prod1);
                ///////////////////////////////////////////////
                // 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.
                // Does not overflow because the denominator cannot be zero at this stage in the function.
                uint256 twos = denominator & (~denominator + 1);
                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 (rounding == Rounding.Up && 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 down.
         *
         * 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 + (rounding == Rounding.Up && result * result < a ? 1 : 0);
            }
        }
        /**
         * @dev Return the log in base 2, rounded down, of a positive value.
         * 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 + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
            }
        }
        /**
         * @dev Return the log in base 10, rounded down, of a positive value.
         * 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 + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
            }
        }
        /**
         * @dev Return the log in base 256, rounded down, of a positive value.
         * 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 10, 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 + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol)
    pragma solidity ^0.8.0;
    import "./math/Math.sol";
    /**
     * @dev String operations.
     */
    library Strings {
        bytes16 private constant _SYMBOLS = "0123456789abcdef";
        uint8 private constant _ADDRESS_LENGTH = 20;
        /**
         * @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), _SYMBOLS))
                    }
                    value /= 10;
                    if (value == 0) break;
                }
                return buffer;
            }
        }
        /**
         * @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) {
            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] = _SYMBOLS[value & 0xf];
                value >>= 4;
            }
            require(value == 0, "Strings: hex length insufficient");
            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);
        }
    }
    // SPDX-License-Identifier: UNLICENSED
    pragma solidity 0.8.19;
    import "@openzeppelin/contracts/access/AccessControl.sol";
    import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
    import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
    /// @author MELD team
    /// @title MeldBankSignup
    /// @notice MeldBankSignup is a contract that allows users to redeem bank signup codes for 1$ worth of tokens
    contract MeldBankSignup is AccessControl {
        using SafeERC20 for IERC20;
        /// @dev Address to identify native token
        address public constant NATIVE_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
        /// @dev Error messages
        string public constant ERR_ADMIN_ZERO_ADDRESS =
            "MeldBankSignup: Default admin cannot be the zero address";
        string public constant ERR_FEE_RECEIVER_ZERO_ADDRESS =
            "MeldBankSignup: Fee Receiver cannot be the zero address";
        string public constant ERR_TOKEN_ZERO_ADDRESS =
            "MeldBankSignup: Token address cannot be the zero address";
        string public constant ERR_TOKEN_NOT_SUPPORTED = "MeldBankSignup: Token not supported";
        string public constant ERR_NATIVE_TOKEN_NOT_SUPPORTED =
            "MeldBankSignup: Native token not supported";
        string public constant ERR_ARRAY_LENGTHS =
            "MeldBankSignup: Token addresses and fees lengths mismatch";
        string public constant ERR_NATIVE_TOKEN_AMOUNT =
            "MeldBankSignup: Incorrect native token amount";
        string public constant ERR_NATIVE_TOKEN_TRANSFER =
            "MeldBankSignup: Failed to send native token fee";
        string public constant ERR_CODE_USED = "MeldBankSignup: Code already used";
        /// @dev The fee for redeeming a bank signup code, every token has a fee that is $1 worth of that token approx.
        mapping(address tokenAddress => uint256 fee) public tokenFees;
        /// @dev The bank signup codes that have been redeemed
        mapping(bytes32 => bool) public redeemedCodes;
        /// @dev The address that receives the fees
        address public feeReceiver;
        event TokenFeeChanged(address indexed tokenAddress, uint256 fee);
        event FeeReceiverChanged(address indexed oldFeeReceiver, address indexed newFeeReceiver);
        event BankSignupCodeRedeemed(bytes32 indexed code, address indexed userAddress);
        /// @notice Creates the contract and sets the default admin and fee receiver
        /// @param _defaultAdmin The address that will be the default admin
        /// @param _feeReceiver The address that will receive the fees
        constructor(address _defaultAdmin, address _feeReceiver) {
            require(_defaultAdmin != address(0), ERR_ADMIN_ZERO_ADDRESS);
            require(_feeReceiver != address(0), ERR_FEE_RECEIVER_ZERO_ADDRESS);
            _setupRole(DEFAULT_ADMIN_ROLE, _defaultAdmin);
            feeReceiver = _feeReceiver;
        }
        /// @notice Sets the fee for a list of tokens
        /// @dev Only the admin can call this function
        /// @param _tokenAddresses The list of token addresses
        /// @param _tokenFees The list of fees for each token
        function setFees(
            address[] memory _tokenAddresses,
            uint256[] memory _tokenFees
        ) external onlyRole(DEFAULT_ADMIN_ROLE) {
            require(_tokenAddresses.length == _tokenFees.length, ERR_ARRAY_LENGTHS);
            for (uint256 i = 0; i < _tokenAddresses.length; i++) {
                tokenFees[_tokenAddresses[i]] = _tokenFees[i];
                emit TokenFeeChanged(_tokenAddresses[i], _tokenFees[i]);
            }
        }
        /// @notice Sets the fee receiver
        /// @dev Only the admin can call this function
        /// @param _feeReceiver The new fee receiver
        function setFeeReceiver(address _feeReceiver) external onlyRole(DEFAULT_ADMIN_ROLE) {
            require(_feeReceiver != address(0), ERR_FEE_RECEIVER_ZERO_ADDRESS);
            emit FeeReceiverChanged(feeReceiver, _feeReceiver);
            feeReceiver = _feeReceiver;
        }
        /// @notice Redeems a bank signup code paying 1$ worth of the specified token
        /// @dev The user must approve the contract to spend the token
        /// @param _code The bank signup code
        /// @param _tokenAddress The token address
        function redeemCode(bytes32 _code, address _tokenAddress) external {
            require(!redeemedCodes[_code], ERR_CODE_USED);
            require(_tokenAddress != address(0), ERR_TOKEN_ZERO_ADDRESS);
            require(tokenFees[_tokenAddress] > 0, ERR_TOKEN_NOT_SUPPORTED);
            emit BankSignupCodeRedeemed(_code, msg.sender);
            redeemedCodes[_code] = true;
            IERC20(_tokenAddress).safeTransferFrom(msg.sender, feeReceiver, tokenFees[_tokenAddress]);
        }
        /// @notice Redeems a bank signup code paying 1$ worth of the native token
        /// @dev The user must send the native token
        /// @param _code The bank signup code
        function redeemCodeNative(bytes32 _code) external payable {
            require(!redeemedCodes[_code], ERR_CODE_USED);
            require(tokenFees[NATIVE_TOKEN_ADDRESS] > 0, ERR_NATIVE_TOKEN_NOT_SUPPORTED);
            require(msg.value == tokenFees[NATIVE_TOKEN_ADDRESS], ERR_NATIVE_TOKEN_AMOUNT);
            redeemedCodes[_code] = true;
            emit BankSignupCodeRedeemed(_code, msg.sender);
            (bool sent, ) = payable(feeReceiver).call{value: msg.value}("");
            require(sent, ERR_NATIVE_TOKEN_TRANSFER);
        }
    }