// SPDX-License-Identifier: UNLICENSED

/*

Why? Because while his name, and even his initials, were blocked by the government, the image got through the country’s censors. The spreading of the meme has been called “guerrilla activism.”

https://freecgc.com
https://twitter.com/freecgcerc20
https://t.me/FreeCGC

*/

pragma solidity 0.8.17;

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);
        uint256 c = a - b;

        return c;
    }
    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);
        uint256 c = a / b;
        return c;
    }
}

interface ERC20 {
    function getOwner() external view returns (address);
    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 Auth {
    address internal owner;

    constructor(address _owner) {
        owner = _owner;
    }

    modifier onlyOwner() {
        require(isOwner(msg.sender), "!OWNER"); _;
    }

    function isOwner(address account) public view returns (bool) {
        return account == owner;
    }

    function renounceOwnership() external onlyOwner {
        owner = address(0);
    }

}

interface IDEXFactory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

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;
}

contract ERC20FREECGC is ERC20, Auth {
    using SafeMath for uint256;

    address immutable WETH;
    address constant DEAD = 0x000000000000000000000000000000000000dEaD;
    address constant ZERO = 0x0000000000000000000000000000000000000000;

    string public constant name = "FreeCGC";
    string public constant symbol = unicode"免费CGC";
    uint8 public constant decimals = 18;
    
    uint256 public constant totalSupply = 10 * 10**9 * 10**decimals;

    uint256 public _maxWalletToken = totalSupply / 100;

    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) _allowances;

    mapping (address => bool) public isFeeExempt;
    mapping (address => bool) public isWalletLimitExempt;

    uint256 public totalFee = 10;
    uint256 public constant feeDenominator = 100;
    
    uint256 buyMultiplier = 200;
    uint256 sellMultiplier = 200;
    uint256 transferMultiplier = 0;


    IDEXRouter public router;
    address public immutable pair;

    bool public swapEnabled = true;
    uint256 swapThreshold = totalSupply / 100;
    bool inSwap;
    modifier swapping() { inSwap = true; _; inSwap = false; }

    constructor () Auth(msg.sender) {
        router = IDEXRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        WETH = router.WETH();

        pair = IDEXFactory(router.factory()).createPair(WETH, address(this));
        _allowances[address(this)][address(router)] = type(uint256).max;

        isFeeExempt[msg.sender] = true;

        isWalletLimitExempt[msg.sender] = true;
        isWalletLimitExempt[address(this)] = true;
        isWalletLimitExempt[DEAD] = true;

        balanceOf[msg.sender] = totalSupply;
        emit Transfer(address(0), msg.sender, totalSupply);
    }

    receive() external payable { }

    function getOwner() external view override returns (address) { return owner; }
    function allowance(address holder, address spender) external view override returns (uint256) { return _allowances[holder][spender]; }

    function approve(address spender, uint256 amount) public override returns (bool) {
        _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 transfer(address recipient, uint256 amount) external override returns (bool) {
        return _transferFrom(msg.sender, recipient, amount);
    }

    function transferFrom(address sender, address recipient, uint256 amount) external override returns (bool) {
        if(_allowances[sender][msg.sender] != type(uint256).max){
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender].sub(amount, "Insufficient Allowance");
        }

        return _transferFrom(sender, recipient, amount);
    }

    function setMaxWalletPercent_base1000(uint256 maxWallPercent_base1000) external onlyOwner {
        _maxWalletToken = (totalSupply * maxWallPercent_base1000 ) / 1000;
    }


    function _transferFrom(address sender, address recipient, uint256 amount) internal returns (bool) {
        if(inSwap){ return _basicTransfer(sender, recipient, amount); }

        if (!isWalletLimitExempt[sender] && !isWalletLimitExempt[recipient] && recipient != pair) {
            require((balanceOf[recipient] + amount) <= _maxWalletToken,"max wallet limit reached");
        }
    
        if(shouldSwapBack()){ swapBack(); }

        balanceOf[sender] = balanceOf[sender].sub(amount, "Insufficient Balance");

        uint256 amountReceived = (isFeeExempt[sender] || isFeeExempt[recipient]) ? amount : takeFee(sender, amount, recipient);

        balanceOf[recipient] = balanceOf[recipient].add(amountReceived);

        emit Transfer(sender, recipient, amountReceived);
        return true;
    }
    
    function _basicTransfer(address sender, address recipient, uint256 amount) internal returns (bool) {
        balanceOf[sender] = balanceOf[sender].sub(amount, "Insufficient Balance");
        balanceOf[recipient] = balanceOf[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function takeFee(address sender, uint256 amount, address recipient) internal returns (uint256) {
        if(amount == 0 || totalFee == 0){
            return amount;
        }

        uint256 multiplier = transferMultiplier;

        if(recipient == pair) {
            multiplier = sellMultiplier;
        } else if(sender == pair) {
            multiplier = buyMultiplier;
        }

        uint256 feeAmount = amount.mul(totalFee).mul(multiplier).div(feeDenominator * 100);

        if(feeAmount > 0){
            balanceOf[address(this)] = balanceOf[address(this)].add(feeAmount);
            emit Transfer(sender, address(this), feeAmount);
        }

        return amount.sub(feeAmount);
    }

    function shouldSwapBack() internal view returns (bool) {
        return msg.sender != pair
        && !inSwap
        && swapEnabled
        && balanceOf[address(this)] >= swapThreshold;
    }

    function clearStuckBalance(uint256 amountPercentage) external onlyOwner {
        uint256 amountETH = address(this).balance;
        uint256 amountToClear = ( amountETH * amountPercentage ) / 100;
        payable(msg.sender).transfer(amountToClear);
    }

    function clearStuckToken(address tokenAddress, uint256 tokens) external onlyOwner returns (bool success) {
        if(tokens == 0){
            tokens = ERC20(tokenAddress).balanceOf(address(this));
        }
        return ERC20(tokenAddress).transfer(msg.sender, tokens);
    }

    function swapBack() internal swapping {

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = WETH;

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            swapThreshold,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    function setMultipliers(uint256 _buy, uint256 _sell) external onlyOwner {
        sellMultiplier = _sell;
        buyMultiplier = _buy;
    }

    function setSwapBackSettings(bool _enabled, uint256 _denominator) external onlyOwner {
        swapEnabled = _enabled;
        swapThreshold = totalSupply / _denominator;
    }

    function getCirculatingSupply() public view returns (uint256) {
        return (totalSupply - balanceOf[DEAD] - balanceOf[ZERO]);
    }
}