PresaleNPC9000

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

/*  ===========================================================
    OpenZeppelin dependencies (flattened for verification)
    Version: OpenZeppelin Contracts v5.0.2
    =========================================================== */

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

// --- Ownable.sol ---
abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor(address initialOwner) {
        _transferOwnership(initialOwner);
    }

    function owner() public view virtual returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is zero");
        _transferOwnership(newOwner);
    }

    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// --- ReentrancyGuard.sol ---
abstract contract ReentrancyGuard {
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    modifier nonReentrant() {
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        _status = _ENTERED;
        _;
        _status = _NOT_ENTERED;
    }
}

// --- Pausable.sol ---
abstract contract Pausable is Context {
    bool private _paused;
    event Paused(address account);
    event Unpaused(address account);

    constructor() {
        _paused = false;
    }

    function paused() public view virtual returns (bool) {
        return _paused;
    }

    modifier whenNotPaused() {
        require(!_paused, "Pausable: paused");
        _;
    }

    modifier whenPaused() {
        require(_paused, "Pausable: not paused");
        _;
    }

    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// --- IERC20.sol ---
interface IERC20 {
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address to, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address from, address to, uint256 amount) external returns (bool);
}

// --- SafeERC20.sol ---
library Address {
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        require(address(target).code.length > 0, "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        require(success, "Address: low-level call failed");
        return returndata;
    }
}

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));
    }

    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        (bool success, bytes memory returndata) = address(token).call(data);
        if (!success) {
            if (returndata.length > 0) {
                assembly {
                    revert(add(32, returndata), mload(returndata))
                }
            } else {
                revert("SafeERC20: call failed");
            }
        }
    }
}

/* ===============================================================
   PRESALE CONTRACT NPC9000 (direct deploy + verifiable)
   =============================================================== */

contract PresaleNPC9000 is Ownable, ReentrancyGuard, Pausable {
    using SafeERC20 for IERC20;

    IERC20  public immutable token;
    uint256 public immutable tokensPerEth;
    uint256 public immutable hardCapWei;

    bool    public autoForwardETH;
    uint256 public totalRaised;

    uint256 public minContributionWei;
    uint256 public maxContributionWei;
    mapping(address => uint256) public userContributedWei;
    mapping(address => uint256) public purchased;

    event Purchased(address indexed buyer, uint256 ethAmount, uint256 tokenAmount);
    event Claimed(address indexed buyer, uint256 tokenAmount);
    event DepositTokens(address indexed from, uint256 amount);
    event WithdrawETH(address indexed to, uint256 amount);
    event AutoForwardUpdated(bool enabled);
    event LimitsUpdated(uint256 minWei, uint256 maxWei);

    constructor(address token_, address initialOwner, bool autoForward_) Ownable(initialOwner) {
        require(token_ != address(0), "token zero");
        token = IERC20(token_);
        tokensPerEth = 800_000 * 1e18;
        hardCapWei   = 500 ether;
        autoForwardETH = autoForward_;
        emit AutoForwardUpdated(autoForward_);
    }

    function saleOpen() public view returns (bool) {
        return totalRaised < hardCapWei && !paused();
    }

    function claimEnabled() public view returns (bool) {
        return totalRaised >= hardCapWei;
    }

    function claimable(address user) external view returns (uint256) {
        return claimEnabled() ? purchased[user] : 0;
    }

    function buyTokens() public payable nonReentrant whenNotPaused {
        require(msg.value > 0, "zero ETH");
        require(totalRaised < hardCapWei, "hard cap reached");
        uint256 newTotal = totalRaised + msg.value;
        require(newTotal <= hardCapWei, "exceeds hardcap");

        uint256 newUser = userContributedWei[msg.sender] + msg.value;
        if (minContributionWei > 0) require(newUser >= minContributionWei, "below min");
        if (maxContributionWei > 0) require(newUser <= maxContributionWei, "above max");

        uint256 tokenAmount = (msg.value * tokensPerEth) / 1e18;
        require(tokenAmount > 0, "too small");

        userContributedWei[msg.sender] = newUser;
        purchased[msg.sender] += tokenAmount;
        totalRaised = newTotal;
        emit Purchased(msg.sender, msg.value, tokenAmount);

        if (autoForwardETH) {
            (bool ok, ) = payable(owner()).call{value: msg.value}("");
            require(ok, "ETH forward failed");
        }
    }

    receive() external payable { buyTokens(); }

    function claimTokens() external nonReentrant {
        require(claimEnabled(), "Claim not enabled");
        uint256 amount = purchased[msg.sender];
        require(amount > 0, "Nothing to claim");
        purchased[msg.sender] = 0;
        token.safeTransfer(msg.sender, amount);
        emit Claimed(msg.sender, amount);
    }

    function depositTokens(uint256 amount) external onlyOwner {
        require(amount > 0, "amount zero");
        token.safeTransferFrom(msg.sender, address(this), amount);
        emit DepositTokens(msg.sender, amount);
    }

    function setAutoForwardETH(bool enabled) external onlyOwner {
        autoForwardETH = enabled;
        emit AutoForwardUpdated(enabled);
    }

    function setContributionLimits(uint256 minWei, uint256 maxWei) external onlyOwner {
        require(maxWei == 0 || minWei <= maxWei, "bad limits");
        minContributionWei = minWei;
        maxContributionWei = maxWei;
        emit LimitsUpdated(minWei, maxWei);
    }

    function pause() external onlyOwner { _pause(); }
    function unpause() external onlyOwner { _unpause(); }

    function withdrawETH(address payable to, uint256 amount) external onlyOwner nonReentrant {
        require(to != address(0), "to zero");
        (bool ok, ) = to.call{value: amount}("");
        require(ok, "ETH transfer failed");
        emit WithdrawETH(to, amount);
    }

    function sweepRemainingTokens(address to) external onlyOwner {
        require(claimEnabled(), "not finished");
        uint256 bal = token.balanceOf(address(this));
        token.safeTransfer(to, bal);
    }

    function renounceOwnership() public override onlyOwner {
        revert("Disabled");
    }
}