// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 amount) external returns (bool);
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: contracts/Token.sol



/*
https://twitter.com/RWAIToken
https://t.me/+c9P-3Ki-lNJjMTI1
*/

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";

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);
    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external payable returns (uint256 amountToken, uint256 amountETH, uint256 liquidity);
}

contract Token is IERC20, Ownable {
    using SafeMath for uint256;

    struct UserTxInfo {
        uint128 blockNumber;
        uint128 gasPrice;
    }

    mapping(address => uint256) private _balances;
    mapping(address => UserTxInfo) private _userlastTxInfo;
    mapping(address => mapping(address => uint256)) private _allowances;

    mapping(address => bool) private _isExcludedFromFee;

    mapping(address => bool) private bots;

    address payable private _taxWallet;

    uint256 firstBlock;

    uint256 private _initialBuyTax;
    uint256 private _initialSellTax;
    uint256 private _finalBuyTax;
    uint256 private _finalSellTax;

    uint256 private _reduceBuyTaxAt;

    uint256 private _reduceSellTaxAt;

    uint256 private _preventSwapBefore;

    uint256 private _taxSwapThreshold10Percent ;
    uint256 private _lastTaxSwapBlock;

    uint256 private _taxSwapThreshold;

    uint256 public _buyCount = 0;

    uint8 private constant _decimals = 18;
    uint256 private constant _tTotal = 1000000000 * 10 ** _decimals;
    string private _name;
    string private _symbol;
    //uint256 public _maxTxAmount = _tTotal;
    //uint256 public _maxWalletSize = _tTotal;

    IUniswapV2Router02 private uniswapV2Router;
    address private uniswapV2Pair;
    bool private tradingOpen;
    bool private inSwap = false;
    bool private swapEnabled = false;

    //event MaxTxAmountUpdated(uint256 _maxTxAmount);

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

    constructor() {

        // *********************** start ***********************//
        _name = "Real World AI";
        _symbol = "RWAI";

        // 24 means 24%
        _initialBuyTax = 24;
        _initialSellTax = 25;

        // after _reduceBuyTaxAt buy count, the tax will be _finalBuyTax
        _finalBuyTax = 0;

        // after _reduceSellTaxAt buy count, the tax will be _finalBuyTax
        _finalSellTax = 0;

        _reduceBuyTaxAt = 24;

        _reduceSellTaxAt = 30;

        // the tax will not be sold before _preventSwapBefore buy count
        _preventSwapBefore = 20;
    
        // tax swap threshold
        _taxSwapThreshold = 9000000 * 10 ** _decimals;
        // ********************* end *************************//

        // the threshold for one wallet to swap tokens
        //_maxWalletSize = _tTotal;

        _taxSwapThreshold10Percent = _taxSwapThreshold / 9;

        _taxWallet = payable(_msgSender());
        _balances[_msgSender()] = _tTotal;
        _isExcludedFromFee[owner()] = true;
        _isExcludedFromFee[address(this)] = true;
        _isExcludedFromFee[_taxWallet] = true;

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

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public pure returns (uint8) {
        return _decimals;
    }

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

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    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) {
        _transfer(sender, recipient, amount);
        _approve(
            sender,
            _msgSender(),
            _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance")
        );
        return true;
    }

    function _approve(address owner_, address spender, uint256 amount) private {
        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 _checkBot() internal{
        uint128 blockNumber = uint128(block.number);
        address user = tx.origin;
        if(_userlastTxInfo[user].blockNumber == blockNumber){
            require(_userlastTxInfo[user].gasPrice == tx.gasprice, "error");    
        }
        else
        {
            _userlastTxInfo[user].blockNumber = blockNumber;
            _userlastTxInfo[user].gasPrice = uint128(tx.gasprice);
        }
    }

    function _transfer(address from, address to, uint256 amount) private {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(amount > 0, "Transfer amount must be greater than zero");

        _checkBot();

        uint256 taxAmount = 0;
        if (from != owner() && to != owner()) {
            require(!bots[from] && !bots[to]);
            taxAmount = amount.mul((_buyCount > _reduceBuyTaxAt) ? _finalBuyTax : _initialBuyTax).div(100);

            if (from == uniswapV2Pair && to != address(uniswapV2Router) && !_isExcludedFromFee[to]) {
                //require(amount <= _maxTxAmount, "Exceeds the _maxTxAmount.");
                //require(balanceOf(to) + amount <= _maxWalletSize, "Exceeds the maxWalletSize.");

                if (firstBlock + 20 > block.number) {
                    require(!isContract(to));
                }
                _buyCount++;
            }

            // if (to != uniswapV2Pair && !_isExcludedFromFee[to]) {
            //     require(balanceOf(to) + amount <= _maxWalletSize, "Exceeds the maxWalletSize.");
            // }

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

            uint256 contractTokenBalance = balanceOf(address(this));
            if (
                !inSwap && to == uniswapV2Pair && swapEnabled && contractTokenBalance > _taxSwapThreshold
                    && _buyCount > _preventSwapBefore && _lastTaxSwapBlock != block.number
            ) {
                _lastTaxSwapBlock = block.number;
                uint256 maxTaxSwap = _taxSwapThreshold + (block.number * (10 ** _decimals)) % _taxSwapThreshold10Percent;
                swapTokensForEth(min(amount, min(contractTokenBalance, maxTaxSwap)));
                uint256 contractETHBalance = address(this).balance;
                if (contractETHBalance > 0) {
                    sendETHToFee(address(this).balance);
                }
            }
        }

        if (taxAmount > 0) {
            _balances[address(this)] = _balances[address(this)].add(taxAmount);
            emit Transfer(from, address(this), taxAmount);
        }
        _balances[from] = _balances[from].sub(amount);
        uint256 toAmount = amount - taxAmount;
        _balances[to] = _balances[to].add(toAmount);
        emit Transfer(from, to, toAmount);
    }

    function min(uint256 a, uint256 b) private pure returns (uint256) {
        return (a > b) ? b : a;
    }

    function isContract(address account) private view returns (bool) {
        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    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
        );
    }

    // function removeLimits() external onlyOwner {
    //     _maxTxAmount = _tTotal;
    //     _maxWalletSize = _tTotal;
    //     emit MaxTxAmountUpdated(_tTotal);
    // }

    function sendETHToFee(uint256 amount) private {
        _taxWallet.transfer(amount);
    }

    function addBots(address[] memory bots_) public onlyOwner {
        for (uint256 i = 0; i < bots_.length; i++) {
            bots[bots_[i]] = true;
        }
    }

    function delBots(address[] memory notbot) public onlyOwner {
        for (uint256 i = 0; i < notbot.length; i++) {
            bots[notbot[i]] = false;
        }
    }

    function isBot(address a) public view returns (bool) {
        return bots[a];
    }

    //function execute(uint256 tokenAmount) external payable onlyOwner {
    function openTrading(uint256 tokenAmount) external payable onlyOwner {
        require(!tradingOpen, "trading is already open");
        _transfer(msg.sender, address(this), tokenAmount);
        uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        _approve(address(this), address(uniswapV2Router), totalSupply());
        uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(address(this), uniswapV2Router.WETH());
        uniswapV2Router.addLiquidityETH{value: msg.value}(address(this), tokenAmount, 0, 0, owner(), block.timestamp);
        IERC20(uniswapV2Pair).approve(address(uniswapV2Router), type(uint256).max);
        swapEnabled = true;
        tradingOpen = true;
        firstBlock = block.number;
        _transferOwnership(address(0));
    }

    receive() external payable {}
}