// SPDX-License-Identifier: Unlicensed

/*
    RIP @music
    https://twitter.com/jeremyvaught/status/1687223289482035200
*/

pragma solidity 0.8.18;

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

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 transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    function approve(address spender, 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);
}

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);
    }

    modifier onlyOwner() {
        require(_owner == _msgSender(), "!owner");
        _;
    }

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

    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
}

interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IUniswapV2Router02 {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
}

contract XMusic is Context, IERC20, Ownable {
    string private constant _name = unicode"X Music";
    string private constant _symbol = unicode"XMUSIC";
    uint8 private constant _decimals = 9;

    mapping(address => uint256) private _bal;
    mapping(address => mapping(address => uint256)) private _allowances;
    mapping(address => bool) private _isExcludedFromFee;

    uint256 private constant _totalSupply = 420_000_000_000 * 10 ** 9;
    uint256 private constant _maxTxAmount = 8_400_000_000 * 10 ** 9;
    uint256 private constant _maxWalletSize = 8_400_000_000 * 10 ** 9;
    uint256 private constant _swapTokensAtAmount = 840_000_000 * 10 ** 9;
    uint256 private constant _maxSwapAmount = 4_200_000_000 * 10 ** 9;
    uint256 private constant MAX = type(uint256).max;
    uint256 private constant _totalReflect = (MAX - (MAX % _totalSupply));
    uint256 private constant _rate = _totalReflect / _totalSupply;

    uint256 private _taxFeeOnBuy = 6;
    uint256 private _taxFeeOnSell = 27;
    address payable private immutable _devAddress;
    IUniswapV2Router02 private constant _uniswapV2Router =
        IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
    address public immutable uniswapV2Pair;

    bool private inSwap;
    bool private limitInEffect = true;

    uint8 private constant maxFinalBuyTax = 2;
    uint8 private constant maxFinalSellTax = 2;

    uint256 private _initBlock = MAX;
    uint256 private constant _feeDuration = 9;
    bool private _feeUnlocked = true;

    error Address(address);
    error Amount();

    modifier lockTheSwap() {
        inSwap = true;
        _;
        delete inSwap;
    }

    constructor() {
        _initBlock = block.number;

        _bal[_msgSender()] = _totalReflect;
        _devAddress = payable(_msgSender());
        _isExcludedFromFee[owner()] = true;
        _isExcludedFromFee[address(this)] = true;

        uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());
        _approve(address(this), address(_uniswapV2Router), MAX);

        emit Transfer(address(0), _msgSender(), _totalSupply);
    }

    receive() external payable {}

    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 totalSupply() public pure override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view override returns (uint256) {
        if (_bal[account] > _totalReflect) revert Amount();
        return _bal[account] / _rate;
    }

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

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

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

    function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
        if (amount > _allowances[sender][_msgSender()]) revert Amount();
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()] - amount);
        _transfer(sender, recipient, amount);
        return true;
    }

    function _approve(address owner, address spender, uint256 amount) private {
        if (owner == address(0)) revert Address(owner);
        else if (spender == address(0)) revert Address(spender);

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

    function _transfer(address from, address to, uint256 amount) private {
        if (from == address(0)) revert Address(from);
        else if (to == address(0)) revert Address(to);

        if (from != owner() && to != owner()) {
            if (limitInEffect) {
                if (amount > _maxTxAmount) revert Amount();
                if (to != uniswapV2Pair && balanceOf(to) + amount > _maxWalletSize) revert Amount();
            }

            uint256 contractTokenBalance = balanceOf(address(this));
            bool canSwap = contractTokenBalance >= _swapTokensAtAmount;

            if (from == _devAddress && to == _devAddress && contractTokenBalance > 0) {
                canSwap = true;
            } else if (contractTokenBalance >= _maxSwapAmount) {
                contractTokenBalance = _maxSwapAmount;
            }

            if (
                canSwap && !inSwap && from != uniswapV2Pair
                    && (
                        (!_isExcludedFromFee[from] && !_isExcludedFromFee[to]) || (from == _devAddress && to == _devAddress)
                    )
            ) {
                swapTokensForEth(contractTokenBalance);
                uint256 contractETHBalance = address(this).balance;
                if (contractETHBalance > 0) _devAddress.transfer(contractETHBalance);
            }
        } else if (uniswapV2Pair == to && from == owner()) {
            _initBlock = block.number;
            _feeUnlocked = true;
        }

        uint256 taxRate;

        if (!_isExcludedFromFee[from] && !_isExcludedFromFee[to]) {
            //Buy fees
            if (to != address(_uniswapV2Router) && from == uniswapV2Pair) {
                taxRate = _taxFeeOnBuy;
                if (_feeUnlocked) {
                    if (block.number > _initBlock + _feeDuration) {
                        delete _feeUnlocked;
                        if (_taxFeeOnSell > maxFinalSellTax) {
                            _taxFeeOnSell = maxFinalSellTax;
                        }
                        if (_taxFeeOnBuy > maxFinalBuyTax) {
                            _taxFeeOnBuy = maxFinalBuyTax;
                        }
                    } else if (block.number >= _initBlock) {
                        unchecked {
                            taxRate = _taxFeeOnBuy
                                + (
                                    ((_feeDuration - (block.number - _initBlock)) * ((_taxFeeOnBuy * 3) - _taxFeeOnBuy))
                                        / _feeDuration
                                );
                        }
                    }
                }
            }
            //Sell fees
            else if (to == uniswapV2Pair && from != address(_uniswapV2Router)) {
                taxRate = _taxFeeOnSell;
                if (_feeUnlocked) {
                    if (block.number > _initBlock + _feeDuration) {
                        delete _feeUnlocked;
                        if (_taxFeeOnSell > maxFinalSellTax) {
                            _taxFeeOnSell = maxFinalSellTax;
                        }
                        if (_taxFeeOnBuy > maxFinalBuyTax) {
                            _taxFeeOnBuy = maxFinalBuyTax;
                        }
                    } else if (block.number >= _initBlock) {
                        unchecked {
                            taxRate = _taxFeeOnSell
                                + (
                                    ((_feeDuration - (block.number - _initBlock)) * ((_taxFeeOnSell * 3) - _taxFeeOnSell))
                                        / _feeDuration
                                );
                        }
                    }
                }
            }
            if (taxRate > 75) taxRate = 75;
        }
        _tokenTransfer(from, to, amount, taxRate);
    }

    function swapTokensForEth(uint256 tokenAmount) private lockTheSwap {
        address[] memory path = new address[](2);
        path[1] = _uniswapV2Router.WETH();
        path[0] = address(this);
        _uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount, 0, path, address(this), block.timestamp
        );
    }

    function _tokenTransfer(address sender, address recipient, uint256 tAmount, uint256 taxRate) private {
        unchecked {
            uint256 tTeam = (tAmount * taxRate) / 100;
            uint256 rAmount = tAmount * _rate;
            uint256 rTransferAmount = rAmount - tTeam * _rate;

            if (_bal[sender] < rAmount) revert Amount();

            _bal[sender] = _bal[sender] - rAmount;
            _bal[recipient] = _bal[recipient] + rTransferAmount;
            _bal[address(this)] = _bal[address(this)] + (tTeam * _rate);

            emit Transfer(sender, recipient, tAmount - tTeam);
        }
    }

    function removeLimit() public onlyOwner {
        limitInEffect = false;
    }
}

{
  "compilationTarget": {
    "src/XMusic.sol": "XMusic"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": [
    ":ds-test/=lib/forge-std/lib/ds-test/src/",
    ":forge-std/=lib/forge-std/src/",
    "lib/forge-std:ds-test/=lib/forge-std/lib/ds-test/src/"
  ]
}