NexaCoin

{{
  "language": "Solidity",
  "sources": {
    "nexaca.sol": {
      "content": "// SPDX-License-Identifier: MIT

pragma solidity 0.8.26;

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) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }
    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) {
        return div(a, b, "SafeMath: division by zero");
    }
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        return c;
    }
}

interface BEP20 {
    function getOwner() external view returns (address);
    function balanceOf(address account) external view returns (uint256);
    function transfer(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);
    function transferFrom(address sender, address recipient, 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);
}

abstract contract Auth {
    address internal owner;
    address internal potentialOwner;
    mapping (address => bool) internal authorizations;

    constructor(address _owner) {
        owner = _owner;
        authorizations[_owner] = true;
    }

    modifier onlyOwner() {
        require(isOwner(msg.sender), "!OWNER"); _;
    }

    modifier authorized() {
        require(isAuthorized(msg.sender), "!AUTHORIZED"); _;
    }

    function authorize(address adr) public onlyOwner {
        authorizations[adr] = true;
    }

    function unauthorize(address adr) public onlyOwner {
        require(adr != owner, "OWNER cant be unauthorized");
        authorizations[adr] = false;
    }

    function isOwner(address account) public view returns (bool) {
        return account == owner;
    }

    function isAuthorized(address adr) public view returns (bool) {
        return authorizations[adr];
    }

    function transferOwnership(address payable adr) external onlyOwner {
        require(adr != owner, "Already the owner");
        require(adr != address(0), "Can not be zero address.");
        potentialOwner = adr;
        emit OwnershipNominated(adr);
    }

    function renounceOwnership() external onlyOwner {
        authorizations[owner] = false;
        authorizations[potentialOwner] = false;
        owner = address(0);
        potentialOwner = address(0);
        emit OwnershipTransferred(owner);
    }

    function acceptOwnership() external {
        require(msg.sender == potentialOwner, "You must be nominated as potential owner before you can accept the role.");
        authorizations[owner] = false;
        authorizations[potentialOwner] = true;
        owner = potentialOwner;
        potentialOwner = address(0);
        emit OwnershipTransferred(owner);
    }

    event OwnershipTransferred(address owner);
    event OwnershipNominated(address potentialOwner);
}

interface IDEXFactory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IDEXRouter {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

contract NexaCoin is BEP20, Auth {
    using SafeMath for uint256;

    address immutable WETH;
    address constant DEAD = 0x000000000000000000000000000000000000dEaD;
    address constant ZERO = 0x0000000000000000000000000000000000000000;

    string public constant name = "NexaCoin";
    string public constant symbol = "NEXA";
    uint8 public constant decimals = 18;

    uint256 public constant totalSupply = 1_000_000_000 * 10**decimals;

    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) _allowances;

    mapping (address => bool) public isFeeExempt;

    uint256 sellFee = 1;
    uint256 buyFee = 3;
    uint256 transferFee = 0;

    address public marketingFeeReceiver;

    IDEXRouter public router;
    address public immutable pair;

    bool public tradingOpen = false;

    bool public swapEnabled = false;
    uint256 public swapThreshold = totalSupply / 50;
    bool inSwap;
    modifier swapping() { inSwap = true; _; inSwap = false; }

    constructor () Auth(msg.sender) {
        router = IDEXRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        WETH = router.WETH();

        pair = IDEXFactory(router.factory()).createPair(WETH, address(this));
        _allowances[address(this)][address(router)] = type(uint256).max;

        marketingFeeReceiver = msg.sender;

        isFeeExempt[msg.sender] = true;

        balanceOf[msg.sender] = totalSupply;
        emit Transfer(address(0), msg.sender, totalSupply);
    }

    receive() external payable { }

    function getOwner() external view override returns (address) { return owner; }
    function allowance(address holder, address spender) external view override returns (uint256) { return _allowances[holder][spender]; }

    function approve(address spender, uint256 amount) public override returns (bool) {
        _allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function approveMax(address spender) external returns (bool) {
        return approve(spender, type(uint256).max);
    }

    function transfer(address recipient, uint256 amount) external override returns (bool) {
        return _transferFrom(msg.sender, recipient, amount);
    }

    function transferFrom(address sender, address recipient, uint256 amount) external override returns (bool) {
        if(_allowances[sender][msg.sender] != type(uint256).max){
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender].sub(amount, "Insufficient Allowance");
        }

        return _transferFrom(sender, recipient, amount);
    }

    function _transferFrom(address sender, address recipient, uint256 amount) internal returns (bool) {
        if(inSwap){ return _basicTransfer(sender, recipient, amount); }

        if(!authorizations[sender] && !authorizations[recipient]){
            require(tradingOpen,"Trading not open yet");
        }

        if(shouldSwapBack()){ swapBack(); }

        balanceOf[sender] = balanceOf[sender].sub(amount, "Insufficient Balance");

        uint256 amountReceived = (isFeeExempt[sender] || isFeeExempt[recipient]) ? amount : takeFee(sender, amount, recipient);

        balanceOf[recipient] = balanceOf[recipient].add(amountReceived);

        emit Transfer(sender, recipient, amountReceived);
        return true;
    }
    
    function _basicTransfer(address sender, address recipient, uint256 amount) internal returns (bool) {
        balanceOf[sender] = balanceOf[sender].sub(amount, "Insufficient Balance");
        balanceOf[recipient] = balanceOf[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function takeFee(address sender, uint256 amount, address recipient) internal returns (uint256) {
        uint256 multiplier = transferFee;

        if(recipient == pair) {
            multiplier = sellFee;
        } else if(sender == pair) {
            multiplier = buyFee;
        }

        if(amount == 0 || multiplier == 0){
            return amount;
        }

        uint256 feeAmount = amount.mul(multiplier).div(100);

        if(feeAmount > 0){
            balanceOf[address(this)] = balanceOf[address(this)].add(feeAmount);
            emit Transfer(sender, address(this), feeAmount);
        }

        return amount.sub(feeAmount);
    }

    function shouldSwapBack() internal view returns (bool) {
        return msg.sender != pair
        && !inSwap
        && swapEnabled
        && balanceOf[address(this)] >= swapThreshold;
    }

    function clearStuckBalance(uint256 amountPercentage) external onlyOwner {
        uint256 amountETH = address(this).balance;
        payable(msg.sender).transfer(amountETH * amountPercentage / 100);
    }

    function clearStuckToken(address tokenAddress, uint256 tokens) external onlyOwner returns (bool success) {
        if(tokens == 0){
            tokens = BEP20(tokenAddress).balanceOf(address(this));
        }
        return BEP20(tokenAddress).transfer(msg.sender, tokens);
    }


    function openTrading() external onlyOwner {
        tradingOpen = true;
    }

    function swapBack() internal swapping {
        uint256 amountToSwap = swapThreshold;

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = WETH;

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            payable(marketingFeeReceiver),
            block.timestamp
        );
    }

    function manage_FeeExempt(address[] calldata addresses, bool status) external onlyOwner {
        require(addresses.length < 501,"GAS Error: max limit is 500 addresses");
        for (uint256 i=0; i < addresses.length; ++i) {
            isFeeExempt[addresses[i]] = status;
        }
    }

    function setMultipliers(uint256 _buy, uint256 _sell, uint256 _trans) external onlyOwner {
        sellFee = _sell;
        buyFee = _buy;
        transferFee = _trans;

        require(buyFee <= 5, "Buy tax cannot be more than 5%");
        require(sellFee <= 5, "Sell tax cannot be more than 5%");
        require(transferFee <= 5, "Transfer Tax cannot be more than 5%");
    }

    function setFeeReceivers(address _marketingFeeReceiver) external onlyOwner {
        require(_marketingFeeReceiver != address(0),"Marketing fee address cannot be zero address");
        marketingFeeReceiver = _marketingFeeReceiver;
    }

    function setSwapBackSettings(bool _enabled, uint256 _amount) external onlyOwner {
        require(_amount < (totalSupply/20), "Amount too high, max allowed in 5%");

        swapEnabled = _enabled;
        swapThreshold = _amount;
    }
    
    function getCirculatingSupply() public view returns (uint256) {
        return (totalSupply - balanceOf[DEAD] - balanceOf[ZERO]);
    }
}"
    }
  },
  "settings": {
    "optimizer": {
      "enabled": false,
      "runs": 200
    },
    "outputSelection": {
      "*": {
        "*": [
          "evm.bytecode",
          "evm.deployedBytecode",
          "devdoc",
          "userdoc",
          "metadata",
          "abi"
        ]
      }
    },
    "remappings": []
  }
}}