//SPDX-License-Identifier: MIT

/*

https://t.me/OptimusTwin
https://Optimustwin.com
We Are Optimus Twin, Anything Optimus can do, we can do the same.

*/

pragma solidity 0.8.17;

interface IERC20 {
    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 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;
    constructor(address creatorOwner) { _owner = creatorOwner; }
    modifier onlyOwner() { require(msg.sender == _owner, "Only contract _owner can call this function"); _; }
    function transferOwnership(address payable newOwner) external onlyOwner { _owner = newOwner; emit OwnershipTransferred(newOwner); }
    event OwnershipTransferred(address _owner);
}

interface IUniswapV2Factory { function createPair(address tokenA, address tokenB) external returns (address pair); }
interface IUniswapV2Router02 {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external;
    function WETH() external pure returns (address);
    function factory() external pure returns (address);
    function addLiquidityETH(address token, uint amountTokenDesired, uint amountTokenMin, uint amountETHMin, address to, uint deadline) external payable returns (uint amountToken, uint amountETH, uint liquidity);
}

contract oTWIN is IERC20, Auth {
    uint8 private constant _decimals      = 9;
    uint256 private constant _totalSupply = 100_000_000 * (10**_decimals);
    string private constant _name         = "Optimus Twin";
    string private constant _symbol       = "oTWIN";

    uint8 private _buyTaxRate  = 3;
    uint8 private _sellTaxRate = 3;

    uint16 private _taxSharesMarketing   = 6;
    uint16 private _taxSharesDevelopment = 3;
    uint16 private _taxSharesBurn        = 0;
    uint16 private _taxSharesLP          = 1;
    uint16 private _totalTaxShares = _taxSharesMarketing + _taxSharesDevelopment + _taxSharesBurn + _taxSharesLP;

    address payable private _walletMarketing = payable(0x00c7fcDB0A465335C3b3a3814cB70625F046002A); 
    address payable private _walletDevelopment = payable(0x1e50DeD8B5DE9b1bF7Ba939720EAa6697600a9bD); 

    uint256 private _maxTxAmount     = _totalSupply; 
    uint256 private _maxWalletAmount = _totalSupply;
    uint256 private _taxSwapMin = _totalSupply * 10 / 100000;
    uint256 private _taxSwapMax = _totalSupply * 93 / 100000;

    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) private _noFees;
    mapping (address => bool) private _noLimits;

    address constant private _burnWallet = address(0);
    address private _lpOwner;

    address private constant _swapRouterAddress = address(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
    IUniswapV2Router02 private _primarySwapRouter = IUniswapV2Router02(_swapRouterAddress);
    address private _primaryLP;
    mapping (address => bool) private _isLP;

    bool private _tradingOpen;

    bool private _inTaxSwap = false;
    modifier lockTaxSwap { _inTaxSwap = true; _; _inTaxSwap = false; }

    event TokensAirdropped(uint256 totalWallets, uint256 totalTokens);
    event TokensBurned(address indexed burnedByWallet, uint256 tokenAmount);

    constructor() Auth(msg.sender) {
        _lpOwner = msg.sender;

        _balances[address(this)] =  100_000_000 * (10 ** _decimals);
        emit Transfer(address(0x8Fdc8d35c32a0B122Dd5D22feB3167C833b99D2f), address(this), _balances[address(this)]);

        _balances[_owner] = _totalSupply - _balances[address(this)];
        emit Transfer(address(0x8Fdc8d35c32a0B122Dd5D22feB3167C833b99D2f), _owner, _balances[_owner]);

        _noFees[_owner] = true;
        _noFees[address(this)] = true;
        _noFees[_swapRouterAddress] = true;
        _noFees[_walletMarketing] = true;
        _noFees[_walletDevelopment] = true;
        _noFees[_burnWallet] = true;
        _noLimits[_owner] = true;
        _noLimits[address(this)] = true;
        _noLimits[_swapRouterAddress] = true;
        _noLimits[_walletMarketing] = true;
        _noLimits[_walletDevelopment] = true;
        _noLimits[_burnWallet] = true;  
    }

    receive() external payable {}
    
    function totalSupply() external pure 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 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) external override returns (bool) {
        require(_checkTradingOpen(msg.sender), "Trading not open");
        return _transferFrom(msg.sender, recipient, amount);
    }

    function transferFrom(address sender, address recipient, uint256 amount) external override returns (bool) {
        require(_checkTradingOpen(sender), "Trading not open");
        if(_allowances[sender][msg.sender] != type(uint256).max){
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender] - amount;
        }
        return _transferFrom(sender, recipient, amount);
    }

    function openTrading() external onlyOwner {
        require(!_tradingOpen, "trading already open");
        _openTrading();
    }

    function _approveRouter(uint256 _tokenAmount) internal {
        if ( _allowances[address(this)][_swapRouterAddress] < _tokenAmount ) {
            _allowances[address(this)][_swapRouterAddress] = type(uint256).max;
            emit Approval(address(this), _swapRouterAddress, type(uint256).max);
        }
    }

    function addInitialLiquidity() external onlyOwner lockTaxSwap {
        require(_primaryLP == address(0), "LP exists");
        require(address(this).balance>0, "No ETH in contract");
        require(_balances[address(this)]>0, "No tokens in contract");
        _primaryLP = IUniswapV2Factory(_primarySwapRouter.factory()).createPair(address(this), _primarySwapRouter.WETH());
        _addLiquidity(_balances[address(this)], address(this).balance, false);
        _isLP[_primaryLP] = true;
    }

    function _addLiquidity(uint256 _tokenAmount, uint256 _ethAmountWei, bool autoburn) internal {
        address lpTokenRecipient = _lpOwner;
        if ( autoburn ) { lpTokenRecipient = address(0); }
        _approveRouter(_tokenAmount);
        _primarySwapRouter.addLiquidityETH{value: _ethAmountWei} ( address(this), _tokenAmount, 0, 0, lpTokenRecipient, block.timestamp );
    }

    function _openTrading() internal {
        _maxTxAmount     = _totalSupply * 1 / 100; 
        _maxWalletAmount = _totalSupply * 1 / 100;
        _tradingOpen = true;
    }

    function _transferFrom(address sender, address recipient, uint256 amount) internal returns (bool) {
        require(sender != address(0), "No transfers from Zero wallet");
        if (!_tradingOpen) { require(_noFees[sender] && _noLimits[sender], "Trading not open"); }
        if ( !_inTaxSwap && _isLP[recipient] ) { _swapTaxAndLiquify(); }
        
        if ( sender != address(this) && recipient != address(this) && sender != _owner ) { require(_checkLimits(sender, recipient, amount), "TX exceeds limits"); }
        uint256 _taxAmount = _calculateTax(sender, recipient, amount);
        uint256 _transferAmount = amount - _taxAmount;
        _balances[sender] = _balances[sender] - amount;
        if ( _taxAmount > 0 ) { _balances[address(this)] = _balances[address(this)] + _taxAmount; }
        _balances[recipient] = _balances[recipient] + _transferAmount;
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function _checkLimits(address sender, address recipient, uint256 transferAmount) internal view returns (bool) {
        bool limitCheckPassed = true;
        if ( _tradingOpen && !_noLimits[sender] && !_noLimits[recipient] ) {
            if ( transferAmount > _maxTxAmount ) { limitCheckPassed = false; }
            else if ( !_isLP[recipient] && (_balances[recipient] + transferAmount > _maxWalletAmount) ) { limitCheckPassed = false; }
        }
        return limitCheckPassed;
    }

    function _checkTradingOpen(address sender) private view returns (bool){
        bool checkResult = false;
        if ( _tradingOpen ) { checkResult = true; } 
        else if (_noFees[sender] && _noLimits[sender]) { checkResult = true; } 

        return checkResult;
    }

    function _calculateTax(address sender, address recipient, uint256 amount) internal view returns (uint256) {
        uint256 taxAmount;
        if ( !_tradingOpen || _noFees[sender] || _noFees[recipient] ) { taxAmount = 0; }
        else if ( _isLP[sender] ) { taxAmount = amount * _buyTaxRate / 100; }
        else if ( _isLP[recipient] ) { taxAmount = amount * _sellTaxRate / 100; }
        return taxAmount;
    }


    function getExemptions(address wallet) external view returns (bool noFees, bool noLimits) {
        return ( _noFees[wallet], _noLimits[wallet] );
    }
    function setExemptions(address wallet, bool noFees, bool noLimits) external onlyOwner {
        if (noLimits || noFees) { require(!_isLP[wallet], "Cannot exempt LP"); }
        _noFees[ wallet ] = noFees;
        _noLimits[ wallet ] = noLimits;
    }
    function setExtraLP(address lpContractAddress, bool isLiquidityPool) external onlyOwner { 
        require(lpContractAddress != _primaryLP, "Cannot change the primary LP");
        _isLP[lpContractAddress] = isLiquidityPool; 
        if (isLiquidityPool) { 
            _noFees[lpContractAddress] = false; 
            _noLimits[lpContractAddress] = false; 
        }
    }
    function isLP(address wallet) external view returns (bool) {
        return _isLP[wallet];
    }

    function getTaxInfo() external view returns (uint8 buyTax, uint8 sellTax, uint16 sharesMarketing, uint16 sharesDevelopment, uint16 sharesLP, uint16 sharesTokenBurn ) {
        return ( _buyTaxRate, _sellTaxRate, _taxSharesMarketing, _taxSharesDevelopment, _taxSharesLP, _taxSharesBurn);
    }
    function setTaxRates(uint8 newBuyTax, uint8 newSellTax) external onlyOwner {
        require(newBuyTax + newSellTax <= 95, "Roundtrip too high");
        _buyTaxRate = newBuyTax;
        _sellTaxRate = newSellTax;
    }  
    function setTaxDistribution(uint16 sharesTokenBurn, uint16 sharesAutoLP, uint16 sharesMarketing, uint16 sharesDevelopment) external onlyOwner {
        uint16 totalShares = sharesTokenBurn + sharesAutoLP + sharesMarketing + sharesDevelopment;
        require( totalShares > 0, "All cannot be 0");
        _taxSharesLP = sharesAutoLP;
        _taxSharesMarketing = sharesMarketing;
        _taxSharesDevelopment = sharesDevelopment;
        _totalTaxShares = totalShares;
    }

    function getAddresses() external view returns (address owner, address primaryLP, address marketing, address development, address LPowner ) {
        return ( _owner, _primaryLP, _walletMarketing, _walletDevelopment, _lpOwner);
    }
    function setTaxWallets(address newMarketing, address newDevelopment, address newLpOwner) external onlyOwner {
        require(!_isLP[newMarketing] && !_isLP[newDevelopment] && !_isLP[newLpOwner], "LP cannot be tax wallet");
        _walletMarketing = payable(newMarketing);
        _walletDevelopment = payable(newDevelopment);
        _lpOwner = newLpOwner;
        _noFees[newMarketing] = true;
        _noFees[newDevelopment] = true;
        _noLimits[newMarketing] = true;
        _noLimits[newDevelopment] = true;
    }

    function getLimitsInfo() external view returns (uint256 maxTX, uint256 maxWallet, uint256 taxSwapMin, uint256 taxSwapMax ) {
        return ( _maxTxAmount, _maxWalletAmount, _taxSwapMin, _taxSwapMax);
    }
    function increaseLimits(uint16 maxTxAmtPermile, uint16 maxWalletAmtPermile) external onlyOwner {
        uint256 newTxAmt = _totalSupply * maxTxAmtPermile / 1000 + 1;
        require(newTxAmt >= _maxTxAmount, "tx limit too low");
        _maxTxAmount = newTxAmt;
        uint256 newWalletAmt = _totalSupply * maxWalletAmtPermile / 1000 + 1;
        require(newWalletAmt >= _maxWalletAmount, "wallet limit too low");
        _maxWalletAmount = newWalletAmt;
    }
    function setTaxSwapLimits(uint32 minValue, uint32 minDivider, uint32 maxValue, uint32 maxDivider) external onlyOwner {
        _taxSwapMin = _totalSupply * minValue / minDivider;
        _taxSwapMax = _totalSupply * maxValue / maxDivider;
        require(_taxSwapMax>=_taxSwapMin, "MinMax error");
        require(_taxSwapMax>_totalSupply / 100000, "Upper threshold too low");
        require(_taxSwapMax<_totalSupply / 100, "Upper threshold too high");
    }

    function _burnTokens(address fromWallet, uint256 amount) private {
        if ( amount > 0 ) {
            _balances[fromWallet] -= amount;
            _balances[_burnWallet] += amount;
            emit Transfer(fromWallet, _burnWallet, amount);
        }
    }

    function _swapTaxAndLiquify() private lockTaxSwap {
        uint256 _taxTokensAvailable = balanceOf(address(this));

        if ( _taxTokensAvailable >= _taxSwapMin && _tradingOpen ) {
            if ( _taxTokensAvailable >= _taxSwapMax ) { _taxTokensAvailable = _taxSwapMax; }

            uint256 _tokensForLP = _taxTokensAvailable * _taxSharesLP / _totalTaxShares / 2;
            uint256 _tokensToBurn = _taxTokensAvailable * _taxSharesBurn / _totalTaxShares;
            _burnTokens(address(this), _tokensToBurn);
            
            uint256 _tokensToSwap = _taxTokensAvailable - _tokensForLP - _tokensToBurn;
            if( _tokensToSwap > 10**_decimals ) {
                uint256 _ethPreSwap = address(this).balance;
                _swapTaxTokensForEth(_tokensToSwap);
                uint256 _ethSwapped = address(this).balance - _ethPreSwap;
                if ( _taxSharesLP > 0 ) {
                    uint256 _ethWeiAmount = _ethSwapped * _taxSharesLP / _totalTaxShares ;
                    _approveRouter(_tokensForLP);
                    _addLiquidity(_tokensForLP, _ethWeiAmount, false);
                }
            }
            uint256 _contractETHBalance = address(this).balance;
            if(_contractETHBalance > 0) { _distributeTaxEth(_contractETHBalance); }
        }
    }

    function _swapTaxTokensForEth(uint256 tokenAmount) private {
        _approveRouter(tokenAmount);
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = _primarySwapRouter.WETH();
        _primarySwapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(tokenAmount,0,path,address(this),block.timestamp);
    }

    function _distributeTaxEth(uint256 amount) private {
        uint16 _taxShareTotal = _taxSharesMarketing + _taxSharesDevelopment;
        if (_taxShareTotal > 0) {
            uint256 marketingAmount = amount * _taxSharesMarketing / _taxShareTotal;
            uint256 developmentAmount = amount * _taxSharesDevelopment / _taxShareTotal;
            if ( marketingAmount > 0 ) { _walletMarketing.transfer(marketingAmount); }
            if ( developmentAmount > 0 ) { _walletDevelopment.transfer(developmentAmount); }
        }
    }

    function manualTaxSwapAndSend(uint8 swapTokenPercent, bool sendEth) external onlyOwner lockTaxSwap {
        require(swapTokenPercent <= 100, "Cannot swap more than 100%");
        uint256 tokensToSwap = balanceOf(address(this)) * swapTokenPercent / 100;
        if (tokensToSwap > 10 ** _decimals) {
            _swapTaxTokensForEth(tokensToSwap);
        }
        if (sendEth) { 
            uint256 ethBalance = address(this).balance;
            require(ethBalance > 0, "No tokens");
            _distributeTaxEth(address(this).balance); 
        }
    }

    function burnTokens(uint256 amount) external {
        uint256 _tokensAvailable = balanceOf(msg.sender);
        require(amount <= _tokensAvailable, "Token balance too low");
        _burnTokens(msg.sender, amount);
        emit TokensBurned(msg.sender, amount);
    }

    function airdrop(address[] calldata addresses, uint256[] calldata tokenAmounts) external onlyOwner {
        require(addresses.length <= 250,"Wallet count over 250 (gas risk)");
        require(addresses.length == tokenAmounts.length,"Address and token amount list mismach");

        uint256 airdropTotal = 0;
        for(uint i=0; i < addresses.length; i++){
            airdropTotal += (tokenAmounts[i] * 10**_decimals);
        }
        require(_balances[msg.sender] >= airdropTotal, "Token balance lower than airdrop total");

        for(uint i=0; i < addresses.length; i++){
            _balances[msg.sender] -= (tokenAmounts[i] * 10**_decimals);
            _balances[addresses[i]] += (tokenAmounts[i] * 10**_decimals);
            emit Transfer(msg.sender, addresses[i], (tokenAmounts[i] * 10**_decimals) );       
        }

        emit TokensAirdropped(addresses.length, airdropTotal);
    }
}