//SPDX-License-Identifier: MIT

//safesurge

pragma solidity 0.8.17;

abstract contract ReentrancyGuard {
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    modifier nonReentrant() {
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        _status = _ENTERED;
        _;
        _status = _NOT_ENTERED;
    }
}

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
    );

    function decimals() external view returns (uint8);
}

interface ISRG {
    function calculatePrice() external view returns (uint256);

    function getBNBPrice() external view returns (uint256);
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return payable(msg.sender);
    }
}

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() public 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;
    }
}

contract SAFESURGE is IERC20, Context, Ownable, ReentrancyGuard {
    event Bought(
        address indexed from,
        address indexed to,
        uint256 tokens,
        uint256 beans,
        uint256 dollarBuy
    );
    event Sold(
        address indexed from,
        address indexed to,
        uint256 tokens,
        uint256 beans,
        uint256 dollarSell
    );
    event FeesMulChanged(uint256 newBuyMul, uint256 newSellMul);
    event StablePairChanged(address newStablePair, address newStableToken);
    event MaxBagChanged(uint256 newMaxBag);

    // token data
    string private constant _name = "SAFESURGE";
    string private constant _symbol = "SAFESURGE";
    uint8 private constant _decimals = 9;
    uint256 private constant _DECMULTIPLIER = 10**_decimals;

    //SRG pair data
    address private constant SRG = 0xcD682EF09d07668d49A8103ddD65Ff54AebFbfDe; //change this according to chain
    ISRG private constant SRGI = ISRG(SRG); //interface to interact with SRG
    IERC20 private constant SRGIE = IERC20(SRG); //interace to interact with SRG

    uint256 private _srgDecimals = SRGIE.decimals();

    // Total Supply
    uint256 public constant _totalSupply = 10**8 * _DECMULTIPLIER;

    // balances
    mapping(address => uint256) public _balances;
    mapping(address => mapping(address => uint256)) internal _allowances;

    //Fees
    mapping(address => bool) public isFeeExempt;
    uint256 public sellMul = 96;
    uint256 public buyMul = 96;
    uint256 public constant DIVISOR = 100;

    //Max bag requirements
    mapping(address => bool) public isTxLimitExempt;
    uint256 public maxBag = _totalSupply / 50;

    //Tax collection
    uint256 public taxBalance = 0;

    //Tax wallets
    address public teamWallet = 0x1E43881d582B5f9a7FDDc38Ed842FC653e3b054c;
    address public treasuryWallet = 0x45b9EE4F4eaa7df7afaDcECEf77D3C80fe75154D;

    // Tax Split
    uint256 public teamShare = 50;
    uint256 public treasuryShare = 50;
    uint256 public constant SHAREDIVISOR = 100;

    //Known Wallets
    address private constant DEAD = 0x000000000000000000000000000000000000dEaD;

    //trading parameters
    uint256 public liquidity = 15**5 * 10**_srgDecimals;
    uint256 public liqConst = liquidity * _totalSupply;
    uint256 public constant TRADE_OPEN_TIME = 1673866156;

    //volume trackers
    mapping(address => uint256) public indVol;
    mapping(uint256 => uint256) public tVol;
    uint256 public totalVolume = 0;

    //candlestick data
    uint256 public constant PADDING = 10**18;
    uint256 public totalTx;
    mapping(uint256 => uint256) public txTimeStamp;

    struct candleStick {
        uint256 time;
        uint256 open;
        uint256 close;
        uint256 high;
        uint256 low;
    }

    mapping(uint256 => candleStick) public candleStickData;

    //Frontrun Guard
    mapping(address => uint256) private _lastBuyBlock;

    // initialize supply
    constructor() {
        _balances[address(this)] = _totalSupply;

        isFeeExempt[msg.sender] = true;

        isTxLimitExempt[msg.sender] = true;
        isTxLimitExempt[address(this)] = true;
        isTxLimitExempt[DEAD] = true;
        isTxLimitExempt[address(0)] = true;
        //burn to be added here if needed

        emit Transfer(address(0), address(this), _totalSupply);
    }

    function totalSupply() external pure override returns (uint256) {
        return _totalSupply;
    }

    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 name() public pure returns (string memory) {
        return _name;
    }

    function symbol() public pure returns (string memory) {
        return _symbol;
    }

    function decimals() public pure returns (uint8) {
        return _decimals;
    }

    function approve(address spender, uint256 amount)
        public
        override
        returns (bool)
    {
        require(spender != address(0), "SRG20: approve to the zero address");
        require(
            msg.sender != address(0),
            "SRG20: approve from the zero address"
        );

        _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 getCirculatingSupply() public view returns (uint256) {
        return _totalSupply - _balances[DEAD];
    }

    function changeWalletLimit(uint256 newLimit) external onlyOwner {
        require(
            newLimit >= _totalSupply / 100,
            "New wallet limit should be at least 1% of total supply"
        );
        maxBag = newLimit;
        emit MaxBagChanged(newLimit);
    }

    function changeIsFeeExempt(address holder, bool exempt) external onlyOwner {
        isFeeExempt[holder] = exempt;
    }

    function changeIsTxLimitExempt(address holder, bool exempt)
        external
        onlyOwner
    {
        isTxLimitExempt[holder] = exempt;
    }

    /** Transfer Function */
    function transfer(address recipient, uint256 amount)
        external
        override
        returns (bool)
    {
        return _transferFrom(msg.sender, recipient, amount);
    }

    /** TransferFrom Function */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external override returns (bool) {
        address spender = msg.sender;
        //check allowance requirement
        _spendAllowance(sender, spender, amount);
        return _transferFrom(sender, recipient, amount);
    }

    /** Internal Transfer */
    function _transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (bool) {
        // make standard checks
        require(
            recipient != address(0) && recipient != address(this),
            "transfer to the zero address or CA"
        );
        require(amount > 0, "Transfer amount must be greater than zero");
        require(
            isTxLimitExempt[recipient] ||
                _balances[recipient] + amount <= maxBag,
            "Max wallet exceeded!"
        );

        // subtract from sender
        _balances[sender] = _balances[sender] - amount;

        // give amount to receiver
        _balances[recipient] = _balances[recipient] + amount;

        // Transfer Event
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "SRG20: burn from the zero address");

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "SRG20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }

        emit Transfer(account, address(0), amount);
    }

    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = _allowances[owner][spender];
        if (currentAllowance != type(uint256).max) {
            require(
                currentAllowance >= amount,
                "SRG20: insufficient allowance"
            );

            unchecked {
                // decrease allowance
                _approve(owner, spender, currentAllowance - 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);
    }

    /** Purchases SURGE Tokens and Deposits Them in Sender's Address*/
    function _buy(
        uint256 buyAmount,
        uint256 minTokenOut,
        uint256 deadline
    ) public nonReentrant returns (bool) {
        // deadline requirement
        require(deadline >= block.timestamp, "Deadline EXPIRED");

        // Frontrun Guard
        _lastBuyBlock[msg.sender] = block.number;

        // liquidity is set
        require(liquidity > 0, "The token has no liquidity");

        // check if trading is open
        require(
            block.timestamp >= TRADE_OPEN_TIME,
            "Trading is not Open"
        );

        //remove the buy tax
        uint256 srgAmount = isFeeExempt[msg.sender]
            ? buyAmount
            : (buyAmount * buyMul) / DIVISOR;

        // how much they should purchase?
        uint256 tokensToSend = _balances[address(this)] -
            (liqConst / (srgAmount + liquidity));

        //revert for max bag
        require(
            _balances[msg.sender] + tokensToSend <= maxBag ||
                isTxLimitExempt[msg.sender],
            "Max wallet exceeded"
        );

        // revert if under 1
        require(tokensToSend > 1, "SRG20: Must Buy more than 1 decimal");

        // revert for slippage
        require(tokensToSend >= minTokenOut, "INSUFFICIENT OUTPUT AMOUNT");
        
        // transfer the SRG from the msg.sender to the CA
        bool s = SRGIE.transferFrom(msg.sender, address(this), buyAmount);

        require(s, "transfer of SRG failed!");

        // transfer the tokens from CA to the buyer
        buy(msg.sender, tokensToSend);

        //update available tax to extract and Liquidity
        uint256 taxAmount = buyAmount - srgAmount;
        taxBalance = taxBalance + taxAmount;
        liquidity = liquidity + srgAmount;

        //update volume
        uint256 cTime = block.timestamp;
        uint256 dollarBuy = buyAmount * getSRGPrice();
        totalVolume += dollarBuy;
        indVol[msg.sender] += dollarBuy;
        tVol[cTime] += dollarBuy;

        //update candleStickData
        totalTx += 1;
        txTimeStamp[totalTx] = cTime;
        uint256 cPrice = calculatePrice() * getSRGPrice();
        candleStickData[cTime].time = cTime;
        if (candleStickData[cTime].open == 0) {
            if (totalTx == 1) {
                candleStickData[cTime].open =
                    ((liquidity - srgAmount) / (_totalSupply)) *
                    getSRGPrice();
            } else {
                candleStickData[cTime].open = candleStickData[
                    txTimeStamp[totalTx - 1]
                ].close;
            }
        }
        candleStickData[cTime].close = cPrice;

        if (
            candleStickData[cTime].high < cPrice ||
            candleStickData[cTime].high == 0
        ) {
            candleStickData[cTime].high = cPrice;
        }

        if (
            candleStickData[cTime].low > cPrice ||
            candleStickData[cTime].low == 0
        ) {
            candleStickData[cTime].low = cPrice;
        }

        //emit transfer and buy events
        emit Transfer(address(this), msg.sender, tokensToSend);
        emit Bought(
            msg.sender,
            address(this),
            tokensToSend,
            buyAmount,
            srgAmount * getSRGPrice()
        );
        return true;
    }

    /** Sends Tokens to the buyer Address */
    function buy(address receiver, uint256 amount) internal {
        _balances[receiver] = _balances[receiver] + amount;
        _balances[address(this)] = _balances[address(this)] - amount;
    }

    /** Sells SURGE Tokens And Deposits the BNB into Seller's Address */
    function _sell(
        uint256 tokenAmount,
        uint256 deadline,
        uint256 minBNBOut
    ) public nonReentrant returns (bool) {
        // deadline requirement
        require(deadline >= block.timestamp, "Deadline EXPIRED");

        //Frontrun Guard
        require(
            _lastBuyBlock[msg.sender] != block.number,
            "Buying and selling in the same block is not allowed!"
        );

        address seller = msg.sender;

        // make sure seller has this balance
        require(
            _balances[seller] >= tokenAmount,
            "cannot sell above token amount"
        );

        // get how much beans are the tokens worth
        uint256 amountSRG = liquidity -
            (liqConst / (_balances[address(this)] + tokenAmount));
        uint256 amountTax = (amountSRG * (DIVISOR - sellMul)) / DIVISOR;
        uint256 SRGtoSend = amountSRG - amountTax;

        //slippage revert
        require(amountSRG >= minBNBOut, "INSUFFICIENT OUTPUT AMOUNT");

        // send SRG to Seller

        bool successful = isFeeExempt[msg.sender]
            ? SRGIE.transfer(msg.sender, amountSRG)
            : SRGIE.transfer(msg.sender, SRGtoSend);
        require(successful, "SRG transfer failed");

        // subtract full amount from sender
        _balances[seller] = _balances[seller] - tokenAmount;

        //add tax allowance to be withdrawn and remove from liq the amount of beans taken by the seller
        taxBalance = isFeeExempt[msg.sender]
            ? taxBalance
            : taxBalance + amountTax;
        liquidity = liquidity - amountSRG;

        // add tokens back into the contract
        _balances[address(this)] = _balances[address(this)] + tokenAmount;

        //update volume
        uint256 cTime = block.timestamp;
        uint256 dollarSell = amountSRG * getSRGPrice();
        totalVolume += dollarSell;
        indVol[msg.sender] += dollarSell;
        tVol[cTime] += dollarSell;

        //update candleStickData
        totalTx += 1;
        txTimeStamp[totalTx] = cTime;
        uint256 cPrice = calculatePrice() * getSRGPrice();
        candleStickData[cTime].time = cTime;
        if (candleStickData[cTime].open == 0) {
            candleStickData[cTime].open = candleStickData[
                txTimeStamp[totalTx - 1]
            ].close;
        }
        candleStickData[cTime].close = cPrice;

        if (
            candleStickData[cTime].high < cPrice ||
            candleStickData[cTime].high == 0
        ) {
            candleStickData[cTime].high = cPrice;
        }

        if (
            candleStickData[cTime].low > cPrice ||
            candleStickData[cTime].low == 0
        ) {
            candleStickData[cTime].low = cPrice;
        }

        // emit transfer and sell events
        emit Transfer(seller, address(this), tokenAmount);
        if (isFeeExempt[msg.sender]) {
            emit Sold(
                address(this),
                msg.sender,
                tokenAmount,
                amountSRG,
                dollarSell
            );
        } else {
            emit Sold(
                address(this),
                msg.sender,
                tokenAmount,
                SRGtoSend,
                SRGtoSend * getSRGPrice()
            );
        }
        return true;
    }

    /** Amount of liquidity in Contract */
    function getLiquidity() public view returns (uint256) {
        return liquidity;
    }

    /** Returns the value of your holdings before the sell fee */
    function getValueOfHoldings(address holder) public view returns (uint256) {
        return
            ((_balances[holder] * liquidity) / _balances[address(this)]) *
            getSRGPrice();
    }

    function changeFees(uint256 newBuyMul, uint256 newSellMul)
        external
        onlyOwner
    {
        require(
            newBuyMul >= 90 &&
                newSellMul >= 90 &&
                newBuyMul <= 100 &&
                newSellMul <= 100,
            "Fees are too high"
        );

        buyMul = newBuyMul;
        sellMul = newSellMul;

        emit FeesMulChanged(newBuyMul, newSellMul);
    }

    function changeTaxDistribution(
        uint256 newteamShare,
        uint256 newtreasuryShare
    ) external onlyOwner {
        require(
            newteamShare + newtreasuryShare == SHAREDIVISOR,
            "Sum of shares must be 100"
        );

        teamShare = newteamShare;
        treasuryShare = newtreasuryShare;
    }

    function changeFeeReceivers(
        address newTeamWallet,
        address newTreasuryWallet
    ) external onlyOwner {
        require(
            newTeamWallet != address(0) && newTreasuryWallet != address(0),
            "New wallets must not be the ZERO address"
        );

        teamWallet = newTeamWallet;
        treasuryWallet = newTreasuryWallet;
    }

    function withdrawTaxBalance() external nonReentrant onlyOwner {
        bool temp1 = SRGIE.transfer(
            teamWallet,
            (taxBalance * teamShare) / SHAREDIVISOR
        );
        bool temp2 = SRGIE.transfer(
            treasuryWallet,
            (taxBalance * treasuryShare) / SHAREDIVISOR
        );
        assert(temp1 && temp2);
        taxBalance = 0;
    }

    function getTokenAmountOut(uint256 amountSRGIn)
        external
        view
        returns (uint256)
    {
        uint256 amountAfter = liqConst / (liquidity - amountSRGIn);
        uint256 amountBefore = liqConst / liquidity;
        return amountAfter - amountBefore;
    }

    function getsrgAmountOut(uint256 amountIn) public view returns (uint256) {
        uint256 srgBefore = liqConst / _balances[address(this)];
        uint256 srgAfter = liqConst / (_balances[address(this)] + amountIn);
        return srgBefore - srgAfter;
    }

    function addLiquidity(uint256 amountSRGLiq) external onlyOwner {
        uint256 tokensToAdd = (_balances[address(this)] * amountSRGLiq) /
            liquidity;
        require(_balances[msg.sender] >= tokensToAdd, "Not enough tokens!");

        bool sLiq = SRGIE.transfer(address(this), amountSRGLiq);
        require(sLiq, "SRG transfer was unsuccesful!");

        uint256 oldLiq = liquidity;
        liquidity = liquidity + amountSRGLiq;
        _balances[address(this)] += tokensToAdd;
        _balances[msg.sender] -= tokensToAdd;
        liqConst = (liqConst * liquidity) / oldLiq;

        emit Transfer(msg.sender, address(this), tokensToAdd);
    }

    function getMarketCap() external view returns (uint256) {
        return (getCirculatingSupply() * calculatePrice() * getSRGPrice());
    }

    // calculate price based on pair SRG price
    function getSRGPrice() public view returns (uint256) {
        return (SRGI.calculatePrice() * SRGI.getBNBPrice()); // return amount of token0 needed to buy token1
    }

    // Returns the Current Price of the Token in SRG
    function calculatePrice() public view returns (uint256) {
        require(liquidity > 0, "No Liquidity");
        return liquidity * PADDING / _balances[address(this)];
    }
}