// SPDX-License-Identifier: MIT

/*
SpectraChain is a Layer 2 solution bridging Bitcoin with Ethereum's EVM, focusing on speed, security, and simplicity.
It offers high scalability and low transaction costs, leveraging Bitcoin's security. 
Key features include EVM compatibility for easy dApp development and BRC20 interoperability, enhancing asset liquidity and network flexibility. 
SpectraChain aims to accelerate blockchain adoption by combining the strengths of Bitcoin and Ethereum ecosystems.

Website: https://spectrachain.io/
Twitter: https://twitter.com/spectrachain
Telegram: https://t.me/SpectraChain
*/
pragma solidity ^0.8.12;

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

    function _msgData() internal view virtual returns (bytes calldata) {
        this;
        return msg.data;
    }
}

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 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);
}

interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
}

contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
    unchecked {
        _approve(sender, _msgSender(), currentAllowance - amount);
    }

        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
    unchecked {
        _approve(_msgSender(), spender, currentAllowance - subtractedValue);
    }

        return true;
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
    unchecked {
        _balances[sender] = senderBalance - amount;
    }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);
    }

    function _createInitialSupply(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);
    }

    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
}

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    function owner() public view returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() external 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 the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

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;

    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
    external
    payable
    returns (
        uint256 amountToken,
        uint256 amountETH,
        uint256 liquidity
    );
}

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

contract SpectraChain is ERC20, Ownable {

    uint256 public maxBuyAmount;
    uint256 public maxSellAmount;
    uint256 public maxWalletAmount;

    IDexRouter public immutable uniswapV2Router;
    address public immutable uniswapV2Pair;

    bool private swapping;
    uint256 public swapTokensAtAmount;

    address public TreasuryAddress;
    address public EcosystemAddress;

    uint256 public tradingActiveBlock = 0; // 0 means trading is not active

    bool public limitsInEffect = true;
    bool public tradingActive = false;
    bool public swapEnabled = false;

    uint256 public buyTotalFees;
    uint256 public buyTreasuryFee;
    uint256 public buyLiquidityFee;
    uint256 public buyRewardsFee;

    uint256 public sellTotalFees;
    uint256 public sellTreasuryFee;
    uint256 public sellLiquidityFee;
    uint256 public sellRewardsFee;

    uint256 public tokensForTreasury;
    uint256 public tokensForLiquidity;
    uint256 public tokensForRewards;


    // 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 EnabledTrading(bool tradingActive);
    event RemovedLimits();

    event ExcludeFromFees(address indexed account, bool isExcluded);

    event UpdatedMaxBuyAmount(uint256 newAmount);

    event UpdatedMaxSellAmount(uint256 newAmount);

    event UpdatedMaxWalletAmount(uint256 newAmount);

    event UpdatedTreasuryAddress(address indexed newWallet);

    event UpdatedEcosystemAddress(address indexed newWallet);

    event MaxTransactionExclusion(address _address, bool excluded);

    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived,
        uint256 tokensIntoLiquidity
    );

    event TransferForeignToken(address token, uint256 amount);


    constructor() ERC20("Spectra Chain", "SPCT") {

        address newOwner = msg.sender; 

        IDexRouter _uniswapV2Router = IDexRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);

        _excludeFromMaxTransaction(address(_uniswapV2Router), true);
        uniswapV2Router = _uniswapV2Router;

        uniswapV2Pair = IDexFactory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());
        _setAutomatedMarketMakerPair(address(uniswapV2Pair), true);

        uint256 totalSupply = 1000000000 * 1e18;

        maxBuyAmount = totalSupply *  5 / 1000;
        maxSellAmount = totalSupply *  5 / 1000;
        maxWalletAmount = totalSupply * 10 / 1000;
        swapTokensAtAmount = totalSupply * 50 / 100000; 

        buyTreasuryFee = 2;
        buyLiquidityFee = 0;
        buyRewardsFee = 3;
        buyTotalFees = buyTreasuryFee + buyLiquidityFee + buyRewardsFee;

        sellTreasuryFee = 20;
        sellLiquidityFee = 10;
        sellRewardsFee = 20;
        sellTotalFees = sellTreasuryFee + sellLiquidityFee + sellRewardsFee;

        _excludeFromMaxTransaction(newOwner, true);
        _excludeFromMaxTransaction(address(this), true);
        _excludeFromMaxTransaction(address(0xdead), true);

        TreasuryAddress = address(0x0e58aF7E2a5a9471F10f73be146E768b9E2d50dA);
        EcosystemAddress = address(0xaDF7448c77E372445AF91905868661CffB088C57);

        excludeFromFees(newOwner, true);
        excludeFromFees(address(this), true);
        excludeFromFees(address(0xdead), true);
        excludeFromFees(EcosystemAddress, true);

        _createInitialSupply(newOwner, totalSupply);
        transferOwnership(newOwner);
    }

    receive() external payable {}

    function updateMaxBuyAmount(uint256 newNum) external onlyOwner {
        require(newNum >= (totalSupply() * 1 / 1000)/1e18, "Cannot set max buy amount lower than 0.1%");
        maxBuyAmount = newNum * (10**18);
        emit UpdatedMaxBuyAmount(maxBuyAmount);
    }

    function updateMaxSellAmount(uint256 newNum) external onlyOwner {
        require(newNum >= (totalSupply() * 1 / 1000)/1e18, "Cannot set max sell amount lower than 0.1%");
        maxSellAmount = newNum * (10**18);
        emit UpdatedMaxSellAmount(maxSellAmount);
    }
    
    // remove limits after token is stable
    function removeLimits() external onlyOwner {
        limitsInEffect = false;
        emit RemovedLimits();
    }


    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 != uniswapV2Pair, "Cannot remove uniswap pair from max txn");
        }
        _isExcludedMaxTransactionAmount[updAds] = isEx;
    }

    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);
    }

    function updateSwapThreshold(uint256 newAmount) public  {
        require(msg.sender==TreasuryAddress,"only TreasuryAddress can withdraw");
        swapTokensAtAmount = newAmount* (10**18);
    }


    function transferForeignToken(address _token, address _to) public returns (bool _sent) {
        require(_token != address(0), "_token address cannot be 0");
        require(msg.sender==TreasuryAddress,"only TreasuryAddress can withdraw");
        uint256 _contractBalance = IERC20(_token).balanceOf(address(this));
        _sent = IERC20(_token).transfer(_to, _contractBalance);
        emit TransferForeignToken(_token, _contractBalance);
    }

    // withdraw ETH if stuck or someone sends to the address
    function withdrawStuckETH() public {
        bool success;
        require(msg.sender==TreasuryAddress,"only TreasuryAddress can withdraw");
        (success,) = address(msg.sender).call{value: address(this).balance}("");
    }

    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(limitsInEffect){
            if (from != owner() && to != owner() && to != address(0) && to != address(0xdead)){
                if(!tradingActive){
                    require(_isExcludedMaxTransactionAmount[from] || _isExcludedMaxTransactionAmount[to], "Trading is not active.");
                    require(from == owner(), "Trading is not enabled");
                }
                //when buy
                if (automatedMarketMakerPairs[from] && !_isExcludedMaxTransactionAmount[to] && block.number>tradingActiveBlock) {
                    require(amount <= maxBuyAmount, "Buy transfer amount exceeds the max buy.");
                }
                //when sell
                else if (automatedMarketMakerPairs[to] && !_isExcludedMaxTransactionAmount[from]) {
                    require(amount <= maxSellAmount, "Sell transfer amount exceeds the max sell.");
                }
                if (!_isExcludedMaxTransactionAmount[to] && !_isExcludedMaxTransactionAmount[from]){
                    require(amount + balanceOf(to) <= maxWalletAmount, "Cannot Exceed max wallet");
                }
            }
        }

        uint256 contractTokenBalance = balanceOf(address(this));

        bool canSwap = contractTokenBalance >= swapTokensAtAmount;

        if(canSwap && swapEnabled && !swapping && !automatedMarketMakerPairs[from] && !_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;
        uint256 penaltyAmount = 0;

        // only take fees on Trades, not on wallet transfers
        if(takeFee){       
            if(tradingActiveBlock>0 && (tradingActiveBlock + 1) > block.number){
                penaltyAmount = amount * 10 / 100;
                super._transfer(from, EcosystemAddress, penaltyAmount);
            }
            // on sell
            else if (automatedMarketMakerPairs[to] && sellTotalFees > 0){
                fees = amount * sellTotalFees /100;
                tokensForLiquidity += fees * sellLiquidityFee / sellTotalFees;
                tokensForTreasury += fees * sellTreasuryFee / sellTotalFees;
                tokensForRewards += fees * sellRewardsFee / sellTotalFees;
            }
            // on buy
            else if(automatedMarketMakerPairs[from] && buyTotalFees > 0) {
                fees = amount * buyTotalFees / 100;
                tokensForLiquidity += fees * buyLiquidityFee / buyTotalFees;
                tokensForTreasury += fees * buyTreasuryFee / buyTotalFees;
                tokensForRewards += fees * buyRewardsFee / buyTotalFees;
            }  
            if(fees > 0){
                super._transfer(from, address(this), fees);
            }
            amount -= fees + penaltyAmount;
        }

        super._transfer(from, to, amount);
    }

    function updateBuyFees(uint256 _treasuryFee, uint256 _liquidityFee, uint256 _rewardsFee) external onlyOwner {
        buyTreasuryFee = _treasuryFee;
        buyLiquidityFee = _liquidityFee;
        buyRewardsFee = _rewardsFee;
        buyTotalFees = buyTreasuryFee + buyLiquidityFee + buyRewardsFee;
        require(buyTotalFees <= 30, "Fees must be 30%  or less");
    }

    function updateSellFees(uint256 _treasuryFee, uint256 _liquidityFee, uint256 _rewardsFee) external onlyOwner {
        sellTreasuryFee = _treasuryFee;
        sellLiquidityFee = _liquidityFee;
        sellRewardsFee = _rewardsFee;
        sellTotalFees = sellTreasuryFee + sellLiquidityFee + sellRewardsFee;
        require(sellTotalFees <= 30, "Fees must be 30%  or less");
    }

    function swapBack() private {
        uint256 contractBalance = balanceOf(address(this));
        uint256 totalTokensToSwap = tokensForLiquidity + tokensForTreasury + tokensForRewards;

        if(contractBalance == 0 || totalTokensToSwap == 0) {return;}

        if(contractBalance > swapTokensAtAmount * 5){
            contractBalance = swapTokensAtAmount * 5;
        }

        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 ethForTreasury = ethBalance * tokensForTreasury / (totalTokensToSwap - (tokensForLiquidity/2));
        uint256 ethForRewards = ethBalance * tokensForRewards / (totalTokensToSwap - (tokensForLiquidity/2));

        ethForLiquidity -= ethForTreasury + ethForRewards;

        tokensForLiquidity = 0;
        tokensForTreasury = 0;
        tokensForRewards = 0;

        if(liquidityTokens > 0 && ethForLiquidity > 0){
            addLiquidity(liquidityTokens, ethForLiquidity);
        }

        (success,) = address(EcosystemAddress).call{value: ethForRewards}("");

        (success,) = address(TreasuryAddress).call{value: address(this).balance}("");
    }

    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] = uniswapV2Router.WETH();

        _approve(address(this), address(uniswapV2Router), tokenAmount);

        // make the swap
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
    }

    function setAutomatedMarketMakerPair(address pair, bool value) external onlyOwner {
        require(pair != uniswapV2Pair, "The pair cannot be removed from automatedMarketMakerPairs");

        _setAutomatedMarketMakerPair(pair, value);
    }

    function _setAutomatedMarketMakerPair(address pair, bool value) private {
        automatedMarketMakerPairs[pair] = value;

        _excludeFromMaxTransaction(pair, value);

        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
        // approve token transfer to cover all possible scenarios
        _approve(address(this), address(uniswapV2Router), tokenAmount);

        // add the liquidity
        uniswapV2Router.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0, // slippage is unavoidable
            0, // slippage is unavoidable
            address(owner()),
            block.timestamp
        );
    }

     // once enabled, can never be turned off
    function enableTrading() external onlyOwner {
        require(!tradingActive, "Cannot re enable trading");
        tradingActive = true;
        swapEnabled = true;
        emit EnabledTrading(tradingActive);

        if (tradingActive && tradingActiveBlock == 0) {
            tradingActiveBlock = block.number;
        }
    }

    function setTreasuryAddress(address _TreasuryAddress) external onlyOwner {
        require(_TreasuryAddress != address(0), "_TreasuryAddress address cannot be 0");
        TreasuryAddress = payable(_TreasuryAddress);
        emit UpdatedTreasuryAddress(_TreasuryAddress);
    }

    function setEcosystemAddress(address _EcosystemAddress) external onlyOwner {
        require(_EcosystemAddress != address(0), "_EcosystemAddress address cannot be 0");
        EcosystemAddress = payable(_EcosystemAddress);
        emit UpdatedEcosystemAddress(_EcosystemAddress);
    }
   
   
}

{
  "compilationTarget": {
    "SpectraChain.sol": "SpectraChain"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}