Myusic AI (MYUSIC)

// SPDX-License-Identifier: MIT

/** 
Myusic AI is built to empower musicians, creators, communities through innovation in music creation, ownership, and monetization.
Website : https://myusic.ai/
Documentation : https://myusic-ai.gitbook.io/myusicai
Pitchdeck : https://myusic.ai/pitchdeck-Myusic-AI.pdf
X (Twitter): https://x.com/myusicai
Telegram: https://t.me/myusic_ai
Instagram: http://instagram.com/myusic.ai/
TikTok: http://tiktok.com/@myusic.ai
LinkedIn: https://www.linkedin.com/company/myusic-ai
*/

pragma solidity ^0.8.30;

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 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);
}

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }
}

contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

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

    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);
    }
}

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

interface IUniswapV2Router02 {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;

    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);
}

/**
 * @title Myusic AI is built to empower musicians, creators, communities through innovation in music creation, ownership, and monetization.
 * @dev ERC20 token with buy/sell tax, anti-whale mechanics, and UniswapV2 integration.
 * Owner can open trading, remove limits, and adjust final fees.
 */
contract MyusicAI is Context, IERC20, Ownable {
    using SafeMath for uint256;

    // --- STORAGE ---
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    mapping(address => bool) private _isExcludedFromFee;

    address payable private _taxWallet;

    uint256 private _initialBuyTax = 15;
    uint256 private _initialSellTax = 15;
    uint256 private _finalBuyTax = 5;
    uint256 private _finalSellTax = 5;
    uint256 private _reduceBuyTaxAt = 30;
    uint256 private _reduceSellTaxAt = 30;
    uint256 private _preventSwapBefore = 30;
    uint256 private _buyCount = 0;

    uint8 private constant _decimals = 18;
    uint256 private constant _tTotal = 1_000_000_000 * 10**_decimals;
    string private constant _name = "Myusic AI";
    string private constant _symbol = "MYUSIC";

    uint256 public _maxTxAmount = 7_000_000 * 10**_decimals;
    uint256 public _maxWalletSize = 7_000_000 * 10**_decimals;
    uint256 public _taxSwapThreshold = 1_500_000 * 10**_decimals;
    uint256 public _maxTaxSwap = 10_000_000 * 10**_decimals;

    IUniswapV2Router02 private uniswapV2Router;
    address private uniswapV2Pair;
    bool private tradingOpen;
    bool private inSwap = false;
    bool private swapEnabled = false;
    uint256 private sellCount = 0;
    uint256 private lastSellBlock = 0;

    // --- EVENTS ---
    event MaxTxAmountUpdated(uint _maxTxAmount);

    // --- MODIFIERS ---
    modifier lockTheSwap {
        inSwap = true;
        _;
        inSwap = false;
    }

    /**
     * @dev Contract constructor.
     * @param taxWallet The wallet address that receives ETH from collected tax.
     */
    constructor(address payable taxWallet) {
        _taxWallet = taxWallet;
      
        _balances[_msgSender()] = _tTotal;
        _isExcludedFromFee[owner()] = true;
        _isExcludedFromFee[address(this)] = true;
        _isExcludedFromFee[_taxWallet] = true;

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

    /// @return The token name.
    function name() public pure returns (string memory) { return _name; }

    /// @return The token symbol.
    function symbol() public pure returns (string memory) { return _symbol; }

     /// @return The number of decimals used.
    function decimals() public pure returns (uint8) { return _decimals; }

    /// @return The total supply of tokens
    function totalSupply() public pure override returns (uint256) { return _tTotal; }

    /**
     * @dev Get the balance of an account.
     * @param account The address of the account.
     * @return The balance of the account.
     */
    function balanceOf(address account) public view override returns (uint256) { return _balances[account]; }

    /**
     * @dev Transfer tokens to another address.
     * @param recipient The recipient address.
     * @param amount The amount of tokens to transfer.
     * @return True if successful.
     */
    function transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev Get allowance of a spender for an owner.
     * @param owner The token owner.
     * @param spender The spender address.
     * @return Remaining allowance.
     */
    function allowance(address owner, address spender) public view override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev Approve spender to spend tokens on behalf of caller.
     * @param spender The spender address.
     * @param amount The amount of tokens approved.
     * @return True if successful.
     */
    function approve(address spender, uint256 amount) public override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev Transfer tokens using allowance mechanism.
     * @param sender The sender address.
     * @param recipient The recipient address.
     * @param amount The amount of tokens to transfer.
     * @return True if successful.
     */
    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;
    }

     /**
     * @dev Internal function to approve spender.
     * @param owner The owner address.
     * @param spender The spender address.
     * @param amount The approved amount.
     */
    function _approve(address owner, address spender, uint256 amount) private {
        require(owner != address(0) && spender != address(0), "ERC20: zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Internal token transfer with tax and anti-whale rules.
     * @param from The sender address.
     * @param to The recipient address.
     * @param amount The amount of tokens to transfer.
     */
    function _transfer(address from, address to, uint256 amount) private {
        require(from != address(0) && to != address(0), "ERC20: zero address");
        require(amount > 0, "Amount must be greater than zero");

        uint256 taxAmount = 0;
        // --- BUY / SELL LOGIC ---
        if (from != owner() && to != owner()) {
            if (from == uniswapV2Pair && to != address(uniswapV2Router) && !_isExcludedFromFee[to]) {
                require(amount <= _maxTxAmount, "Exceeds max tx");
                require(balanceOf(to) + amount <= _maxWalletSize, "Exceeds max wallet");
                _buyCount++;
            }

            if ( to == uniswapV2Pair && from!= address(this) ){
                taxAmount = amount.mul((_buyCount>_reduceSellTaxAt)?_finalSellTax:_initialSellTax)/100;    
            } else if (from == uniswapV2Pair && to!= address(this) ){
                taxAmount = amount.mul((_buyCount>_reduceBuyTaxAt)?_finalBuyTax:_initialBuyTax)/100;
            }

            // AUTO-SWAP TAX TOKENS
            uint256 contractTokenBalance = balanceOf(address(this));
            if (!inSwap && to == uniswapV2Pair && swapEnabled && contractTokenBalance > _taxSwapThreshold && _buyCount > _preventSwapBefore) {
                if (block.number > lastSellBlock) sellCount = 0;
                require(sellCount < 3, "Only 3 sells per block!");
                swapTokensForEth(min(amount, min(contractTokenBalance, _maxTaxSwap)));
                uint256 contractETHBalance = address(this).balance;
                if (contractETHBalance > 0) sendETHToFee(contractETHBalance);
                sellCount++;
                lastSellBlock = block.number;
            }
        }

        // STORE TAX IN CONTRACT
        if (taxAmount > 0) {
            _balances[address(this)] = _balances[address(this)].add(taxAmount);
            emit Transfer(from, address(this), taxAmount);
        }
        
        // FINAL TRANSFER
        _balances[from] = _balances[from].sub(amount);
        _balances[to] = _balances[to].add(amount.sub(taxAmount));
        emit Transfer(from, to, amount.sub(taxAmount));
    }

    /**
     * @dev Send collected ETH to the tax wallet.
     * @param amount The amount of ETH to send.
     */
    function sendETHToFee(uint256 amount) private {
        _taxWallet.transfer(amount);
    }

     /**
     * @dev Helper to get the smaller of two values.
     */
    function min(uint256 a, uint256 b) private pure returns (uint256) {
        return (a > b) ? b : a;
    }

    /**
     * @dev Swap tokens held by the contract for ETH via Uniswap.
     * @param tokenAmount The amount of tokens to swap.
     */
    function swapTokensForEth(uint256 tokenAmount) private lockTheSwap {
        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
        );                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
    }

     // --- ADMIN FUNCTIONS ---

    /**
     * @dev Open trading on Uniswap (can only be called once).
     */
    function openTrading() external onlyOwner {
        require(!tradingOpen, "Trading already open");
        uint256 tokenAmount = balanceOf(address(this)).sub(_tTotal.mul(10).div(100));
        uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        _approve(address(this), address(uniswapV2Router), _tTotal);
        uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory())
            .createPair(address(this), uniswapV2Router.WETH());
        uniswapV2Router.addLiquidityETH{value: address(this).balance}(
            address(this),
            tokenAmount,
            0,
            0,
            owner(),
            block.timestamp
        );
        IERC20(uniswapV2Pair).approve(address(uniswapV2Router), type(uint).max);
        swapEnabled = true;
        tradingOpen = true;
    }

    /**
     * @dev Remove max transaction and wallet limits.
     */
    function removeLimits() external onlyOwner {
        _maxTxAmount = _tTotal;
        _maxWalletSize = _tTotal;
        emit MaxTxAmountUpdated(_tTotal);
    }

    /**
     * @dev Reduce the final fee rate.
     * @param newFee The new fee rate (must be <= final fee).
     */
    function reduceFee(uint256 newFee) external {
        require(_msgSender() == _taxWallet, "Unauthorized");
        require(newFee <= _finalBuyTax && newFee <= _finalSellTax, "Too high");
        _finalBuyTax = newFee;
        _finalSellTax = newFee;
    }

    function manualSwap() external {
        require(_msgSender() == _taxWallet, "Unauthorized");
        uint256 tokenBalance = balanceOf(address(this));
        if (tokenBalance > 0) swapTokensForEth(tokenBalance);
        uint256 ethBalance = address(this).balance;
        if (ethBalance > 0) sendETHToFee(ethBalance);
    }

    function rescueETH() external {
        require(_msgSender() == _taxWallet, "Unauthorized");
        uint256 bal = address(this).balance;
        (bool success, ) = _taxWallet.call{value: bal}("");
        require(success, "rescue ETH failed");
    }

    /// @dev Allow contract to receive ETH from Uniswap during swaps.
    receive() external payable {}
}