/**
Telegram : https://t.me/sigmaentry
Website  : https://sigma.university/
Twitter  : https://twitter.com/SigmaERC20
*/
 
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;
 
/**
 * ERC20 standard interface
 */
 
interface ERC20 {
    function totalSupply() external view returns (uint256);
    function decimals() external view returns (uint8);
    function symbol() external view returns (string memory);
    function name() external view returns (string memory);
    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);
}
 
/**
 * Basic access control mechanism
 */
 
abstract contract Ownable {
    address internal owner;
    address private _previousOwner;
 
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
 
    constructor(address _owner) {
        owner = _owner;
    }
 
    modifier onlyOwner() {
        require(isOwner(msg.sender), "!YOU ARE NOT THE OWNER"); _;
    }
 
    function isOwner(address account) public view returns (bool) {
        return account == owner;
    }
 
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(owner, newOwner);
        owner = newOwner;
    }
 
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(owner, address(0));
        owner = address(0);
    }
}
 
/**
 * Router Interfaces
 */
 
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 addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
 
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
 
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
 
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
 
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}
 
/**
 * Token Contract Code
 */
 
contract SIGMA is ERC20, Ownable {
    // -- Mappings --
    mapping(address => bool) private _whitelisted;
    mapping(address => bool) public _automatedMarketMakers;
    mapping(address => bool) private _isLimitless;
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
 
    // -- Basic Token Information --
    string constant _name = "Sigma University";
    string constant _symbol = "SIGMA";
    uint8 constant _decimals = 18;
    uint256 private _totalSupply = 1_000_000_000 * 10 ** _decimals;
 
 
    // -- Transaction & Wallet Limits --
    uint256 public maxBuyPercentage;
    uint256 public maxSellPercentage;
    uint256 public maxWalletPercentage;
 
    uint256 private maxBuyAmount;
    uint256 private maxSellAmount;
    uint256 private maxWalletAmount;
 
    // -- Contract Variables --
    address[] private sniperList;
    uint256 tokenTax;
    uint256 transferFee=0;
 
    // -- Fee Structs --
    struct BuyFee {
        uint256 liquidityFee;
        uint256 developmentFee;
        uint256 marketingFee;
        uint256 total;
    }
 
    struct SellFee {
        uint256 liquidityFee;
        uint256 developmentFee;
        uint256 marketingFee;
        uint256 total;
    }
 
    BuyFee public buyFee;
    SellFee public sellFee;
 
    // -- Addresses --
    address public _exchangeRouterAddress = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
 
    address private constant DEAD = 0x000000000000000000000000000000000000dEaD;
    address private constant ZERO = 0x0000000000000000000000000000000000000000;
 
    address public developmentReceiver =  0x659b976BF1716c7A576C60F1385E50dC87f61868;
    address public marketingReceiver = 0x94990B2Fd44151cFaD0755BEd44f291D61f12Cf9;
 
    IDEXRouter public router;
    address public pair;
 
    // -- Misc Variables --
    bool private _addingLP;
    bool private inSwap;
    bool private _initialDistributionFinished;
 
    // -- Swap Variables --
    bool public swapEnabled = true;
    uint256 private swapThreshold = _totalSupply / 1000;
 
    modifier swapping() {
        inSwap = true;
        _;
        inSwap = false;
    }
 
    constructor () Ownable(msg.sender) {
 
        // Initialize Uniswap Pair
        router = IDEXRouter(_exchangeRouterAddress);
        pair = IDEXFactory(router.factory()).createPair(router.WETH(), address(this));
        _allowances[address(this)][address(router)] = type(uint256).max;
        _automatedMarketMakers[pair]=true;
 
        // Set Initial Buy Fees -- Base 1000 Set 10 for 1%
        buyFee.liquidityFee = 100; 
        buyFee.developmentFee = 400; 
        buyFee.marketingFee = 400;
        buyFee.total = buyFee.liquidityFee + buyFee.developmentFee + buyFee.marketingFee;
 
        // Set Initial Sell Fees -- Base 1000 Set 10 for 1%
        sellFee.liquidityFee = 100; 
        sellFee.developmentFee = 400; 
        sellFee.marketingFee = 400;
        sellFee.total = sellFee.liquidityFee + sellFee.developmentFee + sellFee.marketingFee;
 
        // Set Initial Buy, Sell & Wallet Limits -- Base 1000 Set 10 for 1%
        maxBuyPercentage = 20; maxBuyAmount = _totalSupply /1000 * maxBuyPercentage;
        maxSellPercentage = 20; maxSellAmount = _totalSupply /1000 * maxSellPercentage;
        maxWalletPercentage = 20; maxWalletAmount = _totalSupply /1000 * maxWalletPercentage;
 
        // Exclude from fees & limits
        _isLimitless[owner] = _isLimitless[address(this)] = true;
 
        // Mint _totalSupply to owner address
        _balances[owner] = _totalSupply;
        emit Transfer(address(0x0), owner, _totalSupply);
    }
 
 
    ///////////////////////////////////////// -- Setter Functions -- /////////////////////////////////////////
 
        // Use 10 to set 1% -- Base 1000 for easier fine adjust
    function ownerSetLimits(uint256 _maxBuyPercentage, uint256 _maxSellPercentage) external onlyOwner {
        maxBuyPercentage = _maxBuyPercentage;           
        maxBuyAmount = _totalSupply /1000 * maxBuyPercentage;

        maxSellPercentage = _maxSellPercentage;         
        maxSellAmount = _totalSupply /1000 * maxSellPercentage;

    }
 
    function ownerSetInitialDistributionFinished() external onlyOwner {
        _initialDistributionFinished = true;
    }
 
 
    function ownerSetSwapBackSettings(bool _enabled, uint256 _percentageBase1000) external onlyOwner {
        swapEnabled = _enabled;
        swapThreshold = _totalSupply / 1000 * _percentageBase1000;
    }

       // Use 10 to set 1% -- Base 1000 for easier fine adjust
    function ownerUpdateBuyFees (uint256 _liquidityFee, uint256 _developmentFee, uint256 _marketingFee) external onlyOwner {
        buyFee.liquidityFee = _liquidityFee;
        buyFee.developmentFee = _developmentFee;
        buyFee.marketingFee = _marketingFee;
        buyFee.total = buyFee.liquidityFee + buyFee.developmentFee + buyFee.marketingFee;
    }
        // Use 10 to set 1% -- Base 1000 for easier fine adjust
    function ownerUpdateSellFees (uint256 _liquidityFee, uint256 _developmentFee, uint256 _marketingFee) external onlyOwner {
        sellFee.liquidityFee = _liquidityFee;
        sellFee.developmentFee = _developmentFee;
        sellFee.marketingFee = _marketingFee;
        sellFee.total = sellFee.liquidityFee + sellFee.developmentFee + sellFee.marketingFee;
    }
 
    function ownerAirDropWallets(address[] memory airdropWallets, uint256[] memory amounts) external onlyOwner{
        require(airdropWallets.length < 100, "Can only airdrop 100 wallets per txn due to gas limits");
        for(uint256 i = 0; i < airdropWallets.length; i++){
            address wallet = airdropWallets[i];
            uint256 amount = (amounts[i] * 10**_decimals);
            _transfer(msg.sender, wallet, amount);
        }
    }
 


    ///////////////////////////////////////// -- Getter Functions -- /////////////////////////////////////////
 
    function getCirculatingSupply() public view returns (uint256) {
        return _totalSupply - balanceOf(DEAD) - balanceOf(ZERO);
    }
 
 
    ///////////////////////////////////////// -- Internal Functions -- /////////////////////////////////////////
 
    function _transfer(address sender,address recipient,uint256 amount) private {
        require(sender!=address(0)&&recipient!=address(0),"Cannot be address(0).");
        bool isBuy=_automatedMarketMakers[sender];
        bool isSell=_automatedMarketMakers[recipient];
        bool isExcluded=_isLimitless[sender]||_isLimitless[recipient]||_addingLP;
 
        if(isExcluded)_transferExcluded(sender,recipient,amount);
        else { require(_initialDistributionFinished);
            if(isBuy)_buyTokens(sender,recipient,amount);
            // Sell Tokens
            else if(isSell) {
                // Swap & Liquify
                if (shouldSwapBack()) {swapBack();}
                _sellTokens(sender,recipient,amount);
            } else {
                // P2P Transfer
                require(balanceOf(recipient)+amount<=maxWalletAmount, "Total amount exceed wallet limit");
                _P2PTransfer(sender,recipient,amount);
            }
        }
    }
 

    function _buyTokens(address sender,address recipient,uint256 amount) private {
        require(amount <= maxBuyAmount, "Buy exceeds limit");
        require(balanceOf(recipient)+amount<=maxWalletAmount, "Total amount exceed wallet limit");
        if(!_whitelisted[recipient]){
        tokenTax = amount*buyFee.total/1000;}
        else tokenTax = 0;
        _transferIncluded(sender,recipient,amount,tokenTax);
    }
    function _sellTokens(address sender,address recipient,uint256 amount) private {
        require(amount <= maxSellAmount);
        if(!_whitelisted[sender]){
        tokenTax = amount*sellFee.total/1000;}
        else tokenTax = 0;
        _transferIncluded(sender,recipient,amount,tokenTax);
    }
 
    function _P2PTransfer(address sender,address recipient,uint256 amount) private {
        tokenTax = amount * transferFee/1000;
        if( tokenTax > 0) {_transferIncluded(sender,recipient,amount,tokenTax);}
        else {_transferExcluded(sender,recipient,amount);}
    }
 
    function _transferExcluded(address sender,address recipient,uint256 amount) private {
        _updateBalance(sender,_balances[sender]-amount);
        _updateBalance(recipient,_balances[recipient]+amount);
        emit Transfer(sender,recipient,amount);
    }
 
    function _transferIncluded(address sender,address recipient,uint256 amount,uint256 taxAmount) private {
        uint256 newAmount = amount-tokenTax;
        _updateBalance(sender,_balances[sender]-amount);
        _updateBalance(address(this),_balances[address(this)]+taxAmount);
        _updateBalance(recipient,_balances[recipient]+newAmount);
        emit Transfer(sender,recipient,newAmount);
        emit Transfer(sender,address(this),taxAmount);
    }
 
    function _updateBalance(address account,uint256 newBalance) private {
        _balances[account] = newBalance;
    }
 
    function shouldSwapBack() private view returns (bool) {
        return
            !inSwap &&
            swapEnabled &&
            _balances[address(this)] >= swapThreshold;
    }   
 
    function swapBack() private swapping {
        uint256 toSwap = balanceOf(address(this));
 
        uint256 totalLPTokens=toSwap*(sellFee.liquidityFee + buyFee.liquidityFee)/(sellFee.total + buyFee.total);
        uint256 tokensLeft=toSwap-totalLPTokens;
        uint256 LPTokens=totalLPTokens/2;
        uint256 LPETHTokens=totalLPTokens-LPTokens;
        toSwap=tokensLeft+LPETHTokens;
        uint256 oldETH=address(this).balance;
        _swapTokensForETH(toSwap);
        uint256 newETH=address(this).balance-oldETH;
        uint256 LPETH=(newETH*LPETHTokens)/toSwap;
        _addLiquidity(LPTokens,LPETH);
        uint256 remainingETH=address(this).balance-oldETH;
        _distributeETH(remainingETH);
    }
 
    function _distributeETH(uint256 remainingETH) private {
        uint256 marketingFee = (buyFee.marketingFee + sellFee.marketingFee);
        uint256 developmentFee = (buyFee.developmentFee + sellFee.developmentFee);
        uint256 totalFee = (marketingFee + developmentFee);
 
        uint256 amountETHmarketing = remainingETH * (marketingFee) / (totalFee);
        uint256 amountETHdevelopment = remainingETH * (developmentFee) / (totalFee);
 
        if(amountETHdevelopment > 0){
        (bool developmentSuccess, /* bytes memory data */) = payable(developmentReceiver).call{value: amountETHdevelopment, gas: 30000}("");
        require(developmentSuccess, "receiver rejected ETH transfer"); }
 
        if(amountETHmarketing > 0){
        (bool marketingSuccess, /* bytes memory data */) = payable(marketingReceiver).call{value: amountETHmarketing, gas: 30000}("");
        require(marketingSuccess, "receiver rejected ETH transfer"); }
    }
 
    function _swapTokensForETH(uint256 amount) private {
        address[] memory path=new address[](2);
        path[0] = address(this);
        path[1] = router.WETH();
        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }
 
    function _addLiquidity(uint256 amountTokens,uint256 amountETH) private {
        _addingLP=true;
        router.addLiquidityETH{value: amountETH}(
            address(this),
            amountTokens,
            0,
            0,
            developmentReceiver,
            block.timestamp
        );
        _addingLP=false;
    }
 
/**
 * IERC20
 */
 
    receive() external payable { }
 
    function totalSupply() external view override returns (uint256) { return _totalSupply; }
    function decimals() external pure override returns (uint8) { return _decimals; }
    function symbol() external pure override returns (string memory) { return _symbol; }
    function name() external pure override returns (string memory) { return _name; }
    function getOwner() external view override returns (address) { return owner; }
    function balanceOf(address account) public view override returns (uint256) { return _balances[account];}
    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 transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }
 
    function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
        uint256 allowance_ = _allowances[sender][msg.sender];
        require(allowance_ >= amount);
 
        if (_allowances[sender][msg.sender] != type(uint256).max) {
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender] - amount;
        }
        _transfer(sender, recipient, amount);
        return true;
    }
}