Cryo Explorer Ethereum Mainnet

// Sources flattened with hardhat v2.27.1 https://hardhat.org

// SPDX-License-Identifier: MIT

// File @openzeppelin/contracts/utils/[email protected]

// Original license: SPDX_License_Identifier: MIT
// 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/[email protected]

// Original license: SPDX_License_Identifier: MIT
// 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/utils/introspection/[email protected]

// Original license: SPDX_License_Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (utils/introspection/IERC165.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[ERC].
 *
 * 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[ERC 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/[email protected]

// Original license: SPDX_License_Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC165.sol)

pragma solidity >=0.4.16;


// File @openzeppelin/contracts/token/ERC20/[email protected]

// Original license: SPDX_License_Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/IERC20.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
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/interfaces/[email protected]

// Original license: SPDX_License_Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC20.sol)

pragma solidity >=0.4.16;


// File @openzeppelin/contracts/interfaces/[email protected]

// Original license: SPDX_License_Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC1363.sol)

pragma solidity >=0.6.2;


/**
 * @title IERC1363
 * @dev Interface of the ERC-1363 standard as defined in the https://eips.ethereum.org/EIPS/eip-1363[ERC-1363].
 *
 * Defines an extension interface for ERC-20 tokens that supports executing code on a recipient contract
 * after `transfer` or `transferFrom`, or code on a spender contract after `approve`, in a single transaction.
 */
interface IERC1363 is IERC20, IERC165 {
    /*
     * Note: the ERC-165 identifier for this interface is 0xb0202a11.
     * 0xb0202a11 ===
     *   bytes4(keccak256('transferAndCall(address,uint256)')) ^
     *   bytes4(keccak256('transferAndCall(address,uint256,bytes)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256,bytes)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256,bytes)'))
     */

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @param data Additional data with no specified format, sent in call to `spender`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value, bytes calldata data) external returns (bool);
}


// File @openzeppelin/contracts/token/ERC20/utils/[email protected]

// Original license: SPDX_License_Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;


/**
 * @title SafeERC20
 * @dev Wrappers around ERC-20 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 {
    /**
     * @dev An operation with an ERC-20 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 Variant of {safeTransfer} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransfer(IERC20 token, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Variant of {safeTransferFrom} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransferFrom(IERC20 token, address from, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(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.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    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.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    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.
     *
     * NOTE: If the token implements ERC-7674, this function will not modify any temporary allowance. This function
     * only sets the "standard" allowance. Any temporary allowance will remain active, in addition to the value being
     * set here.
     */
    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 Performs an {ERC1363} transferAndCall, with a fallback to the simple {ERC20} transfer if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            safeTransfer(token, to, value);
        } else if (!token.transferAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} transferFromAndCall, with a fallback to the simple {ERC20} transferFrom if the target
     * has no code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferFromAndCallRelaxed(
        IERC1363 token,
        address from,
        address to,
        uint256 value,
        bytes memory data
    ) internal {
        if (to.code.length == 0) {
            safeTransferFrom(token, from, to, value);
        } else if (!token.transferFromAndCall(from, to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} approveAndCall, with a fallback to the simple {ERC20} approve if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * NOTE: When the recipient address (`to`) has no code (i.e. is an EOA), this function behaves as {forceApprove}.
     * Opposedly, when the recipient address (`to`) has code, this function only attempts to call {ERC1363-approveAndCall}
     * once without retrying, and relies on the returned value to be true.
     *
     * Reverts if the returned value is other than `true`.
     */
    function approveAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            forceApprove(token, to, value);
        } else if (!token.approveAndCall(to, value, data)) {
            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 {_callOptionalReturnBool} that reverts if call fails to meet the requirements.
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            let success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            // bubble errors
            if iszero(success) {
                let ptr := mload(0x40)
                returndatacopy(ptr, 0, returndatasize())
                revert(ptr, returndatasize())
            }
            returnSize := returndatasize()
            returnValue := mload(0)
        }

        if (returnSize == 0 ? address(token).code.length == 0 : returnValue != 1) {
            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 silently catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        bool success;
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            returnSize := returndatasize()
            returnValue := mload(0)
        }
        return success && (returnSize == 0 ? address(token).code.length > 0 : returnValue == 1);
    }
}


// File @openzeppelin/contracts/utils/[email protected]

// Original license: SPDX_License_Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (utils/Pausable.sol)

pragma solidity ^0.8.20;

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    bool private _paused;

    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    /**
     * @dev The operation failed because the contract is paused.
     */
    error EnforcedPause();

    /**
     * @dev The operation failed because the contract is not paused.
     */
    error ExpectedPause();

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        if (paused()) {
            revert EnforcedPause();
        }
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        if (!paused()) {
            revert ExpectedPause();
        }
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}


// File @openzeppelin/contracts/utils/[email protected]

// Original license: SPDX_License_Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (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 EIP-1153 (transient storage) is available on the chain you're deploying at,
 * consider using {ReentrancyGuardTransient} instead.
 *
 * 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 ethereum/NocturaPresale.sol

// Original license: SPDX_License_Identifier: MIT
pragma solidity ^0.8.20;





/**
 * @title NocturaPresale
 * @notice Cross-chain presale contract for Noctura (NOC) token on Ethereum
 * @dev This is a proxy contract - actual tokens are on Solana. 
 *      Purchases are recorded here and synced to Solana via the coordinator.
 */
contract NocturaPresale is Ownable, ReentrancyGuard, Pausable {
    using SafeERC20 for IERC20;

    // ==============================================
    // STRUCTS
    // ==============================================

    struct Stage {
        uint256 price;      // Price in USD (6 decimals) per NOC
        uint256 allocation; // NOC allocation for this stage (9 decimals)
        uint256 sold;       // NOC sold in this stage (9 decimals)
    }

    struct UserAllocation {
        uint256 nocAmount;      // Total NOC purchased (9 decimals)
        uint256 usdSpent;       // Total USD spent (6 decimals)
        uint256 ethSpent;       // Total ETH spent (18 decimals)
        address referrer;       // Referrer address
        uint256 referralBonus;  // Referral bonus received (9 decimals)
        bool exists;
    }

    // ==============================================
    // STATE VARIABLES
    // ==============================================

    // Token addresses
    IERC20 public immutable USDT;
    IERC20 public immutable USDC;

    // Coordinator address (for state sync from Solana)
    address public coordinator;

    // Treasury address for receiving funds
    address public treasury;

    // Presale stages (10 stages as per tokenomics)
    Stage[10] public stages;
    uint8 public currentStage;

    // Global tracking
    uint256 public totalSold;        // Total NOC sold (9 decimals)
    uint256 public totalUsdRaised;   // Total USD raised (6 decimals)
    uint256 public remainingSupply;  // Remaining NOC for sale (9 decimals)

    // Price feeds (simplified - in production use Chainlink)
    uint256 public ethPriceUsd;  // ETH price in USD (6 decimals)

    // User allocations
    mapping(address => UserAllocation) public allocations;
    address[] public buyers;

    // Referral tracking
    uint256 public constant REFERRAL_BONUS_PERCENTAGE = 10; // 10%
    mapping(address => uint256) public referralBonuses;
    mapping(address => uint256) public referralCount;
    mapping(address => bool) public hasReceivedReferralBonus; // Track one-time bonus per referrer

    // Constants
    uint256 public constant NOC_DECIMALS = 9;
    uint256 public constant USD_DECIMALS = 6;
    uint256 public constant MIN_PURCHASE_USD = 25 * 10**USD_DECIMALS;  // $25 minimum
    uint256 public constant MAX_PURCHASE_USD = 50000 * 10**USD_DECIMALS; // $50,000 max per transaction
    uint256 public constant MAX_TOTAL_PER_USER_USD = 200000 * 10**USD_DECIMALS; // $200,000 max per user

    // ==============================================
    // EVENTS
    // ==============================================

    event PurchaseRecorded(
        address indexed buyer,
        uint256 paymentAmount,
        string paymentToken,
        uint256 nocAmount,
        uint256 usdValue,
        uint8 stage,
        address referrer
    );

    event ReferralBonusRecorded(
        address indexed referrer,
        address indexed referee,
        uint256 bonusAmount
    );

    event PresalePaused(bool paused);
    event StageAdvanced(uint8 newStage);
    event StateSynced(uint256 totalSold, uint256 remainingSupply, uint8 currentStage);
    event CoordinatorUpdated(address newCoordinator);
    event EthPriceUpdated(uint256 newPrice);

    // ==============================================
    // MODIFIERS
    // ==============================================

    modifier onlyCoordinator() {
        require(msg.sender == coordinator, "Only coordinator");
        _;
    }

    // ==============================================
    // CONSTRUCTOR
    // ==============================================

    constructor(
        address _usdt,
        address _usdc,
        address _coordinator,
        address _treasury,
        uint256 _initialEthPrice
    ) Ownable(msg.sender) {
        require(_usdt != address(0), "Invalid USDT address");
        require(_usdc != address(0), "Invalid USDC address");
        require(_coordinator != address(0), "Invalid coordinator address");
        require(_treasury != address(0), "Invalid treasury address");

        USDT = IERC20(_usdt);
        USDC = IERC20(_usdc);
        coordinator = _coordinator;
        treasury = _treasury;
        ethPriceUsd = _initialEthPrice;

        // Initialize presale stages (prices in USD with 6 decimals)
        // Total allocation: 102,400,000 NOC (40% of 256M)
        stages[0] = Stage(150100, 10240000 * 10**NOC_DECIMALS, 0);   // $0.1501, 10.24M
        stages[1] = Stage(172300, 10240000 * 10**NOC_DECIMALS, 0);   // $0.1723
        stages[2] = Stage(194500, 10240000 * 10**NOC_DECIMALS, 0);   // $0.1945
        stages[3] = Stage(216700, 10240000 * 10**NOC_DECIMALS, 0);   // $0.2167
        stages[4] = Stage(238900, 10240000 * 10**NOC_DECIMALS, 0);   // $0.2389
        stages[5] = Stage(261100, 10240000 * 10**NOC_DECIMALS, 0);   // $0.2611
        stages[6] = Stage(283300, 10240000 * 10**NOC_DECIMALS, 0);   // $0.2833
        stages[7] = Stage(305500, 10240000 * 10**NOC_DECIMALS, 0);   // $0.3055
        stages[8] = Stage(327700, 10240000 * 10**NOC_DECIMALS, 0);   // $0.3277
        stages[9] = Stage(349900, 10240000 * 10**NOC_DECIMALS, 0);   // $0.3499

        remainingSupply = 102400000 * 10**NOC_DECIMALS;
        currentStage = 0;
    }

    // ==============================================
    // PURCHASE FUNCTIONS
    // ==============================================

    /**
     * @notice Purchase NOC tokens with ETH
     * @param referrer Optional referrer address
     */
    function buyWithETH(address referrer) external payable nonReentrant whenNotPaused {
        require(msg.value > 0, "Must send ETH");
        
        // Calculate USD value
        uint256 usdValue = (msg.value * ethPriceUsd) / 10**18;
        require(usdValue >= MIN_PURCHASE_USD, "Below minimum purchase");
        require(usdValue <= MAX_PURCHASE_USD, "Exceeds maximum per transaction");
        
        // Check user total limit ($200,000 max per user)
        require(
            allocations[msg.sender].usdSpent + usdValue <= MAX_TOTAL_PER_USER_USD,
            "Exceeds maximum per user ($200,000)"
        );

        // Calculate NOC amount
        uint256 nocAmount = calculateNocAmount(usdValue);
        require(nocAmount > 0, "Invalid NOC amount");
        require(nocAmount <= remainingSupply, "Exceeds remaining supply");

        // Process purchase
        _processPurchase(msg.sender, nocAmount, usdValue, referrer);

        // Transfer ETH to treasury
        (bool success, ) = treasury.call{value: msg.value}("");
        require(success, "ETH transfer failed");

        // Update user ETH spent
        allocations[msg.sender].ethSpent += msg.value;

        emit PurchaseRecorded(
            msg.sender,
            msg.value,
            "ETH",
            nocAmount,
            usdValue,
            currentStage,
            referrer
        );
    }

    /**
     * @notice Purchase NOC tokens with USDT
     * @param amount USDT amount (6 decimals)
     * @param referrer Optional referrer address
     */
    function buyWithUSDT(uint256 amount, address referrer) external nonReentrant whenNotPaused {
        require(amount >= MIN_PURCHASE_USD, "Below minimum purchase");
        require(amount <= MAX_PURCHASE_USD, "Exceeds maximum per transaction");
        
        // Check user total limit ($200,000 max per user)
        require(
            allocations[msg.sender].usdSpent + amount <= MAX_TOTAL_PER_USER_USD,
            "Exceeds maximum per user ($200,000)"
        );

        // Calculate NOC amount
        uint256 nocAmount = calculateNocAmount(amount);
        require(nocAmount > 0, "Invalid NOC amount");
        require(nocAmount <= remainingSupply, "Exceeds remaining supply");

        // Transfer USDT from user
        USDT.safeTransferFrom(msg.sender, treasury, amount);

        // Process purchase
        _processPurchase(msg.sender, nocAmount, amount, referrer);

        emit PurchaseRecorded(
            msg.sender,
            amount,
            "USDT",
            nocAmount,
            amount,
            currentStage,
            referrer
        );
    }

    /**
     * @notice Purchase NOC tokens with USDC
     * @param amount USDC amount (6 decimals)
     * @param referrer Optional referrer address
     */
    function buyWithUSDC(uint256 amount, address referrer) external nonReentrant whenNotPaused {
        require(amount >= MIN_PURCHASE_USD, "Below minimum purchase");
        require(amount <= MAX_PURCHASE_USD, "Exceeds maximum per transaction");
        
        // Check user total limit ($200,000 max per user)
        require(
            allocations[msg.sender].usdSpent + amount <= MAX_TOTAL_PER_USER_USD,
            "Exceeds maximum per user ($200,000)"
        );

        // Calculate NOC amount
        uint256 nocAmount = calculateNocAmount(amount);
        require(nocAmount > 0, "Invalid NOC amount");
        require(nocAmount <= remainingSupply, "Exceeds remaining supply");

        // Transfer USDC from user
        USDC.safeTransferFrom(msg.sender, treasury, amount);

        // Process purchase
        _processPurchase(msg.sender, nocAmount, amount, referrer);

        emit PurchaseRecorded(
            msg.sender,
            amount,
            "USDC",
            nocAmount,
            amount,
            currentStage,
            referrer
        );
    }

    // ==============================================
    // INTERNAL FUNCTIONS
    // ==============================================

    function _processPurchase(
        address buyer,
        uint256 nocAmount,
        uint256 usdValue,
        address referrer
    ) internal {
        // Initialize user if first purchase
        if (!allocations[buyer].exists) {
            allocations[buyer].exists = true;
            buyers.push(buyer);
        }

        // Update user allocation
        allocations[buyer].nocAmount += nocAmount;
        allocations[buyer].usdSpent += usdValue;

        // Process referral - ONE-TIME ONLY (same as Solana contract)
        // Referral bonus only given on FIRST purchase by the referee
        if (referrer != address(0) && referrer != buyer && allocations[referrer].exists) {
            // Only set referrer if not already set
            if (allocations[buyer].referrer == address(0)) {
                allocations[buyer].referrer = referrer;
            }
            
            // Only award bonus if this is the first purchase (nocAmount was 0 before)
            // Check if buyer has received referral bonus before
            if (!hasReceivedReferralBonus[buyer]) {
                uint256 referralBonus = (nocAmount * REFERRAL_BONUS_PERCENTAGE) / 100;
                referralBonuses[referrer] += referralBonus;
                referralCount[referrer] += 1;
                hasReceivedReferralBonus[buyer] = true;
                
                emit ReferralBonusRecorded(referrer, buyer, referralBonus);
            }
        }

        // Update global state
        totalSold += nocAmount;
        totalUsdRaised += usdValue;
        remainingSupply -= nocAmount;

        // Update stage sold
        stages[currentStage].sold += nocAmount;

        // Auto-advance stage if allocation exhausted
        if (stages[currentStage].sold >= stages[currentStage].allocation && currentStage < 9) {
            currentStage++;
            emit StageAdvanced(currentStage);
        }
    }

    function calculateNocAmount(uint256 usdValue) public view returns (uint256) {
        Stage memory stage = stages[currentStage];
        // nocAmount = usdValue * 10^NOC_DECIMALS / price
        return (usdValue * 10**NOC_DECIMALS) / stage.price;
    }

    // ==============================================
    // VIEW FUNCTIONS
    // ==============================================

    function getUserAllocation(address user) external view returns (
        uint256 nocAmount,
        uint256 usdSpent,
        uint256 ethSpent,
        address referrer,
        uint256 referralBonus
    ) {
        UserAllocation memory alloc = allocations[user];
        return (
            alloc.nocAmount,
            alloc.usdSpent,
            alloc.ethSpent,
            alloc.referrer,
            alloc.referralBonus
        );
    }

    function getStageInfo(uint8 stage) external view returns (
        uint256 price,
        uint256 allocation,
        uint256 sold
    ) {
        require(stage < 10, "Invalid stage");
        Stage memory s = stages[stage];
        return (s.price, s.allocation, s.sold);
    }

    function getCurrentPrice() external view returns (uint256) {
        return stages[currentStage].price;
    }

    function getBuyersCount() external view returns (uint256) {
        return buyers.length;
    }

    function isPaused() external view returns (bool) {
        return paused();
    }

    // ==============================================
    // COORDINATOR FUNCTIONS (State Sync from Solana)
    // ==============================================

    /**
     * @notice Sync state from Solana master chain
     * @dev Called by coordinator to keep EVM contracts in sync
     */
    function syncFromSolana(
        uint256 _totalSold,
        uint256 _remainingSupply,
        uint8 _currentStage
    ) external onlyCoordinator {
        totalSold = _totalSold;
        remainingSupply = _remainingSupply;
        
        if (_currentStage != currentStage && _currentStage < 10) {
            currentStage = _currentStage;
            emit StageAdvanced(_currentStage);
        }

        emit StateSynced(_totalSold, _remainingSupply, _currentStage);
    }

    // ==============================================
    // ADMIN FUNCTIONS
    // ==============================================

    function setCoordinator(address _coordinator) external onlyOwner {
        require(_coordinator != address(0), "Invalid address");
        coordinator = _coordinator;
        emit CoordinatorUpdated(_coordinator);
    }

    function setTreasury(address _treasury) external onlyOwner {
        require(_treasury != address(0), "Invalid address");
        treasury = _treasury;
    }

    function setEthPrice(uint256 _price) external onlyCoordinator {
        require(_price > 0, "Invalid price");
        ethPriceUsd = _price;
        emit EthPriceUpdated(_price);
    }

    function pause(bool _paused) external {
        require(msg.sender == owner() || msg.sender == coordinator, "Not authorized");
        if (_paused) {
            _pause();
        } else {
            _unpause();
        }
        emit PresalePaused(_paused);
    }

    // Emergency withdrawal (only owner)
    function emergencyWithdraw(address token) external onlyOwner {
        if (token == address(0)) {
            uint256 balance = address(this).balance;
            (bool success, ) = treasury.call{value: balance}("");
            require(success, "ETH withdrawal failed");
        } else {
            IERC20 erc20 = IERC20(token);
            uint256 balance = erc20.balanceOf(address(this));
            erc20.safeTransfer(treasury, balance);
        }
    }

    // Receive ETH
    receive() external payable {
        revert("Use buyWithETH()");
    }
}