TokenPreSale

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

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

interface AggregatorV3Interface {
    function latestRoundData()
        external
        view
        returns (
            uint80 roundId,
            int256 answer,
            uint256 startedAt,
            uint256 updatedAt,
            uint80 answeredInRound
        );
}

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

abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    constructor() {
        _owner = _msgSender();
        emit OwnershipTransferred(address(0), _owner);
    }
    function owner() public view virtual returns (address) {
        return _owner;
    }
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }
}

/* Minimal interface to interact with the staking contract */
interface IStaking {
    function stakeFor(address user, uint256 amount) external;
}

contract TokenPreSale is Ownable {
    using SafeMath for uint256;

    IERC20 public token;
    IERC20 public usdt;
    AggregatorV3Interface public priceFeed;

    address public treasuryWallet;
    address public stakingContract; // new

    // Hard cap and soft cap (both in USD value, 18 decimals)
    uint256 public constant HARD_CAP = 7_560_000 * 1e18; // $7,560,000
    uint256 public constant SOFT_CAP = HARD_CAP / 100;  // $75,600

    uint256 public totalETHRaised;
    uint256 public totalUSDTRaised;
    uint256 public totalSold;

    // Token price set to $0.000005 per token
    uint256 public tokenPriceInUSDT = 0.000005 ether;

    bool public saleActive = true;
    bool public claimEnabled = false;

    mapping(address => uint256) public pendingTokens;

    event Sell(address indexed buyer, uint256 tokenAmount, uint256 value, string paymentMethod);
    event SellAndStake(address indexed buyer, uint256 tokenAmount, uint256 value, string paymentMethod);
    event Withdraw(address indexed owner, uint256 amount);
    event ClaimStatusChanged(bool newStatus);
    event TokenPriceUpdated(uint256 newPrice);
    event TokensClaimed(address indexed user, uint256 amount);

    constructor(
        address _token,
        address _usdt,
        address _priceFeed,
        address _treasuryWallet,
        address _stakingContract
    ) {
        require(_token != address(0), "Invalid token address");
        require(_usdt != address(0), "Invalid USDT address");
        require(_priceFeed != address(0), "Invalid price feed address");
        require(_treasuryWallet != address(0), "Invalid treasury address");
        require(_stakingContract != address(0), "Invalid staking address");

        token = IERC20(_token);
        usdt = IERC20(_usdt);
        priceFeed = AggregatorV3Interface(_priceFeed);
        treasuryWallet = _treasuryWallet;
        stakingContract = _stakingContract;
    }

    receive() external payable {
        buyAndStakeWithETH();
    }

    // ==================== PRICE HELPERS ====================
    function getLatestETHPrice() public view returns (uint256) {
        (, int256 price, , , ) = priceFeed.latestRoundData();
        return uint256(price).mul(1e10); // convert from 8 to 18 decimals
    }

    function getTokenPriceInETH() public view returns (uint256) {
        uint256 ethPriceInUSD = getLatestETHPrice();
        return tokenPriceInUSDT.mul(1e18).div(ethPriceInUSD);
    }

    function getTotalRaisedInUSD() public view returns (uint256) {
        uint256 ethUSD = getLatestETHPrice(); // 1 ETH = X USD (18 decimals)
        uint256 totalETHinUSD = totalETHRaised.mul(ethUSD).div(1e18);
        uint256 totalUSDTinUSD = totalUSDTRaised; // USDT already 1:1 USD
        return totalETHinUSD.add(totalUSDTinUSD);
    }

    // ==================== BUY WITH ETH ====================
    function buyWithETH() public payable {
        require(saleActive, "Sale not active");
        require(msg.value > 0, "No ETH sent");

        uint256 ethAmount = msg.value;
        uint256 newRaisedUSD = getTotalRaisedInUSD();
        uint256 ethValueUSD = ethAmount.mul(getLatestETHPrice()).div(1e18);
        require(newRaisedUSD.add(ethValueUSD) <= HARD_CAP, "Hard cap reached");

        uint256 tokenPriceInETH = getTokenPriceInETH();
        uint256 tokenAmount = ethAmount.mul(1e18).div(tokenPriceInETH);
        require(token.balanceOf(address(this)) >= tokenAmount, "Not enough tokens");

        totalETHRaised = totalETHRaised.add(ethAmount);
        pendingTokens[msg.sender] = pendingTokens[msg.sender].add(tokenAmount);

        (bool success, ) = treasuryWallet.call{value: ethAmount}("");
        require(success, "ETH transfer failed");

        emit Sell(msg.sender, tokenAmount, ethAmount, "ETH");
    }

    // ==================== BUY WITH USDT ====================
    function buyWithUSDT(uint256 usdtAmount) public {
        require(saleActive, "Sale not active");
        require(usdtAmount > 0, "Invalid USDT amount");

        uint256 newRaisedUSD = getTotalRaisedInUSD();
        require(newRaisedUSD.add(usdtAmount) <= HARD_CAP, "Hard cap reached");

        uint256 tokenAmount = usdtAmount.mul(1e18).div(tokenPriceInUSDT);
        require(token.balanceOf(address(this)) >= tokenAmount, "Not enough tokens");

        totalUSDTRaised = totalUSDTRaised.add(usdtAmount);
        pendingTokens[msg.sender] = pendingTokens[msg.sender].add(tokenAmount);

        require(usdt.transferFrom(msg.sender, treasuryWallet, usdtAmount), "USDT transfer failed");

        emit Sell(msg.sender, tokenAmount, usdtAmount, "USDT");
    }

    // ==================== NEW: BUY AND STAKE WITH ETH ====================
    function buyAndStakeWithETH() public payable {
        require(saleActive, "Sale not active");
        require(msg.value > 0, "No ETH sent");
        require(stakingContract != address(0), "Staking not set");

        uint256 ethAmount = msg.value;
        uint256 newRaisedUSD = getTotalRaisedInUSD();
        uint256 ethValueUSD = ethAmount.mul(getLatestETHPrice()).div(1e18);
        require(newRaisedUSD.add(ethValueUSD) <= HARD_CAP, "Hard cap reached");

        uint256 tokenPriceInETH = getTokenPriceInETH();
        uint256 tokenAmount = ethAmount.mul(1e18).div(tokenPriceInETH);
        require(token.balanceOf(address(this)) >= tokenAmount, "Not enough tokens in presale");

        totalETHRaised = totalETHRaised.add(ethAmount);

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

        // Transfer tokens from presale contract to staking contract
        require(token.transfer(stakingContract, tokenAmount), "Token transfer to staking failed");

        // Call staking contract to record the stake on behalf of buyer
        IStaking(stakingContract).stakeFor(msg.sender, tokenAmount);

        emit SellAndStake(msg.sender, tokenAmount, ethAmount, "ETH");
    }

    // ==================== NEW: BUY AND STAKE WITH USDT ====================
    function buyAndStakeWithUSDT(uint256 usdtAmount) public {
        require(saleActive, "Sale not active");
        require(usdtAmount > 0, "Invalid USDT amount");
        require(stakingContract != address(0), "Staking not set");

        uint256 newRaisedUSD = getTotalRaisedInUSD();
        require(newRaisedUSD.add(usdtAmount) <= HARD_CAP, "Hard cap reached");

        uint256 tokenAmount = usdtAmount.mul(1e18).div(tokenPriceInUSDT);
        require(token.balanceOf(address(this)) >= tokenAmount, "Not enough tokens in presale");

        totalUSDTRaised = totalUSDTRaised.add(usdtAmount);

        // Transfer USDT to treasury
        require(usdt.transferFrom(msg.sender, treasuryWallet, usdtAmount), "USDT transfer failed");

        // Transfer tokens from presale contract to staking contract
        require(token.transfer(stakingContract, tokenAmount), "Token transfer to staking failed");

        // Call staking contract to record the stake on behalf of buyer
        IStaking(stakingContract).stakeFor(msg.sender, tokenAmount);

        emit SellAndStake(msg.sender, tokenAmount, usdtAmount, "USDT");
    }

    // ==================== CLAIM TOKENS ====================
    function claimTokens() public {
        require(claimEnabled, "Claim not enabled");
        uint256 amount = pendingTokens[msg.sender];
        require(amount > 0, "No tokens to claim");

        pendingTokens[msg.sender] = 0;
        require(token.transfer(msg.sender, amount), "Token transfer failed");

        emit TokensClaimed(msg.sender, amount);
    }

    // ==================== ADMIN FUNCTIONS ====================
    function setClaimEnabled(bool _enabled) external onlyOwner {
        claimEnabled = _enabled;
        emit ClaimStatusChanged(_enabled);
    }

    function withdraw() public onlyOwner {
        uint256 balance = address(this).balance;
        require(balance > 0, "No ETH to withdraw");
        payable(msg.sender).transfer(balance);
        emit Withdraw(msg.sender, balance);
    }

    function setSaleStatus(bool _status) external onlyOwner {
        saleActive = _status;
    }

    function endSale() public onlyOwner {
        uint256 remaining = token.balanceOf(address(this));
        if (remaining > 0) token.transfer(msg.sender, remaining);
        saleActive = false;
    }

    function updateTokenPriceInUSDT(uint256 _newPrice) external onlyOwner {
        require(_newPrice > 0, "Invalid price");
        tokenPriceInUSDT = _newPrice;
        emit TokenPriceUpdated(_newPrice);
    }

    function emergencyWithdrawTokens() external onlyOwner {
        uint256 remaining = token.balanceOf(address(this));
        require(token.transfer(msg.sender, remaining), "Token transfer failed");
    }

    function setStakingContract(address _staking) external onlyOwner {
        require(_staking != address(0), "Invalid staking");
        stakingContract = _staking;
    }
}