// SPDX-License-Identifier: MIT
pragma solidity ^0.6.12;

    abstract contract Context {
        function _msgSender() internal view virtual returns (address payable) {
            return msg.sender;
        }

        function _msgData() internal view virtual returns (bytes memory) {
            this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
            return msg.data;
        }
    }

    interface IERC20 {
        /**
        * @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 `recipient`.
        *
        * Returns a boolean value indicating whether the operation succeeded.
        *
        * Emits a {Transfer} event.
        */
        function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);

        /**
        * @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);
    }

    library SafeMath {
        /**
        * @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) {
            uint256 c = a + b;
            require(c >= a, "SafeMath: addition overflow");

            return c;
        }

        /**
        * @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 sub(a, b, "SafeMath: subtraction overflow");
        }

        /**
        * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
        * overflow (when the result is negative).
        *
        * Counterpart to Solidity's `-` operator.
        *
        * Requirements:
        *
        * - Subtraction cannot overflow.
        */
        function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
            require(b <= a, errorMessage);
            uint256 c = a - b;

            return c;
        }

        /**
        * @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) {
            // 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 0;
            }

            uint256 c = a * b;
            require(c / a == b, "SafeMath: multiplication overflow");

            return c;
        }

        /**
        * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
            return div(a, b, "SafeMath: division by zero");
        }

        /**
        * @dev Returns the integer division of two unsigned integers. Reverts 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) {
            require(b > 0, errorMessage);
            uint256 c = a / b;
            // assert(a == b * c + a % b); // There is no case in which this doesn't hold

            return c;
        }

        /**
        * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
        * Reverts 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 mod(a, b, "SafeMath: modulo by zero");
        }

        /**
        * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
        * Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
            require(b != 0, errorMessage);
            return a % b;
        }
    }

    library Address {
        /**
        * @dev Returns true if `account` is a contract.
        *
        * [IMPORTANT]
        * ====
        * It is unsafe to assume that an address for which this function returns
        * false is an externally-owned account (EOA) and not a contract.
        *
        * Among others, `isContract` will return false for the following
        * types of addresses:
        *
        *  - an externally-owned account
        *  - a contract in construction
        *  - an address where a contract will be created
        *  - an address where a contract lived, but was destroyed
        * ====
        */
        function isContract(address account) internal view returns (bool) {
            // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
            // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
            // for accounts without code, i.e. `keccak256('')`
            bytes32 codehash;
            bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
            // solhint-disable-next-line no-inline-assembly
            assembly { codehash := extcodehash(account) }
            return (codehash != accountHash && codehash != 0x0);
        }

        /**
        * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
        * `recipient`, forwarding all available gas and reverting on errors.
        *
        * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
        * of certain opcodes, possibly making contracts go over the 2300 gas limit
        * imposed by `transfer`, making them unable to receive funds via
        * `transfer`. {sendValue} removes this limitation.
        *
        * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
        *
        * IMPORTANT: because control is transferred to `recipient`, care must be
        * taken to not create reentrancy vulnerabilities. Consider using
        * {ReentrancyGuard} or the
        * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
        */
        function sendValue(address payable recipient, uint256 amount) internal {
            require(address(this).balance >= amount, "Address: insufficient balance");

            // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
            (bool success, ) = recipient.call{ value: amount }("");
            require(success, "Address: unable to send value, recipient may have reverted");
        }

        /**
        * @dev Performs a Solidity function call using a low level `call`. A
        * plain`call` is an unsafe replacement for a function call: use this
        * function instead.
        *
        * If `target` reverts with a revert reason, it is bubbled up by this
        * function (like regular Solidity function calls).
        *
        * Returns the raw returned data. To convert to the expected return value,
        * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
        *
        * Requirements:
        *
        * - `target` must be a contract.
        * - calling `target` with `data` must not revert.
        *
        * _Available since v3.1._
        */
        function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
        }

        /**
        * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
        * `errorMessage` as a fallback revert reason when `target` reverts.
        *
        * _Available since v3.1._
        */
        function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
            return _functionCallWithValue(target, data, 0, errorMessage);
        }

        /**
        * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
        * but also transferring `value` wei to `target`.
        *
        * Requirements:
        *
        * - the calling contract must have an ETH balance of at least `value`.
        * - the called Solidity function must be `payable`.
        *
        * _Available since v3.1._
        */
        function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
            return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
        }

        /**
        * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
        * with `errorMessage` as a fallback revert reason when `target` reverts.
        *
        * _Available since v3.1._
        */
        function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
            require(address(this).balance >= value, "Address: insufficient balance for call");
            return _functionCallWithValue(target, data, value, errorMessage);
        }

        function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
            require(isContract(target), "Address: call to non-contract");

            // solhint-disable-next-line avoid-low-level-calls
            (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
            if (success) {
                return returndata;
            } else {
                // Look for revert reason and bubble it up if present
                if (returndata.length > 0) {
                    // The easiest way to bubble the revert reason is using memory via assembly

                    // solhint-disable-next-line no-inline-assembly
                    assembly {
                        let returndata_size := mload(returndata)
                        revert(add(32, returndata), returndata_size)
                    }
                } else {
                    revert(errorMessage);
                }
            }
        }
    }

    contract Ownable is Context {
        address private _owner;
        address private _previousOwner;
        uint256 private _lockTime;

        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

        /**
        * @dev Initializes the contract setting the deployer as the initial owner.
        */
        constructor () internal {
            address msgSender = _msgSender();
            _owner = msgSender;
            emit OwnershipTransferred(address(0), msgSender);
        }

        /**
        * @dev Returns the address of the current owner.
        */
        function owner() public view returns (address) {
            return _owner;
        }

        /**
        * @dev Throws if called by any account other than the owner.
        */
        modifier onlyOwner() {
            require(_owner == _msgSender(), "Ownable: caller is not the owner");
            _;
        }

        /**
        * @dev Leaves the contract without owner. It will not be possible to call
        * `onlyOwner` functions anymore. Can only be called by the current owner.
        *
        * NOTE: Renouncing ownership will leave the contract without an owner,
        * thereby removing any functionality that is only available to the owner.
        */
        function renounceOwnership() public virtual onlyOwner {
            emit OwnershipTransferred(_owner, address(0));
            _owner = 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");
            emit OwnershipTransferred(_owner, newOwner);
            _owner = newOwner;
        }

        function geUnlockTime() public view returns (uint256) {
            return _lockTime;
        }

        //Locks the contract for owner for the amount of time provided
        function lock(uint256 time) public virtual onlyOwner {
            _previousOwner = _owner;
            _owner = address(0);
            _lockTime = now + time;
            emit OwnershipTransferred(_owner, address(0));
        }
        
        //Unlocks the contract for owner when _lockTime is exceeds
        function unlock() public virtual {
            require(_previousOwner == msg.sender, "You don't have permission to unlock");
            require(now > _lockTime , "Contract is locked until 7 days");
            emit OwnershipTransferred(_owner, _previousOwner);
            _owner = _previousOwner;
        }
    }  

    interface IUniswapV2Factory {
        event PairCreated(address indexed token0, address indexed token1, address pair, uint);

        function feeTo() external view returns (address);
        function feeToSetter() external view returns (address);

        function getPair(address tokenA, address tokenB) external view returns (address pair);
        function allPairs(uint) external view returns (address pair);
        function allPairsLength() external view returns (uint);

        function createPair(address tokenA, address tokenB) external returns (address pair);

        function setFeeTo(address) external;
        function setFeeToSetter(address) external;
    } 

    interface IUniswapV2Pair {
        event Approval(address indexed owner, address indexed spender, uint value);
        event Transfer(address indexed from, address indexed to, uint value);

        function name() external pure returns (string memory);
        function symbol() external pure returns (string memory);
        function decimals() external pure returns (uint8);
        function totalSupply() external view returns (uint);
        function balanceOf(address owner) external view returns (uint);
        function allowance(address owner, address spender) external view returns (uint);

        function approve(address spender, uint value) external returns (bool);
        function transfer(address to, uint value) external returns (bool);
        function transferFrom(address from, address to, uint value) external returns (bool);

        function DOMAIN_SEPARATOR() external view returns (bytes32);
        function PERMIT_TYPEHASH() external pure returns (bytes32);
        function nonces(address owner) external view returns (uint);

        function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

        event Mint(address indexed sender, uint amount0, uint amount1);
        event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
        event Swap(
            address indexed sender,
            uint amount0In,
            uint amount1In,
            uint amount0Out,
            uint amount1Out,
            address indexed to
        );
        event Sync(uint112 reserve0, uint112 reserve1);

        function MINIMUM_LIQUIDITY() external pure returns (uint);
        function factory() external view returns (address);
        function token0() external view returns (address);
        function token1() external view returns (address);
        function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
        function price0CumulativeLast() external view returns (uint);
        function price1CumulativeLast() external view returns (uint);
        function kLast() external view returns (uint);

        function mint(address to) external returns (uint liquidity);
        function burn(address to) external returns (uint amount0, uint amount1);
        function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
        function skim(address to) external;
        function sync() external;

        function initialize(address, address) external;
    }

    interface IUniswapV2Router01 {
        function factory() external pure returns (address);
        function WETH() external pure returns (address);

        function addLiquidity(
            address tokenA,
            address tokenB,
            uint amountADesired,
            uint amountBDesired,
            uint amountAMin,
            uint amountBMin,
            address to,
            uint deadline
        ) external returns (uint amountA, uint amountB, uint liquidity);
        function addLiquidityETH(
            address token,
            uint amountTokenDesired,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline
        ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
        function removeLiquidity(
            address tokenA,
            address tokenB,
            uint liquidity,
            uint amountAMin,
            uint amountBMin,
            address to,
            uint deadline
        ) external returns (uint amountA, uint amountB);
        function removeLiquidityETH(
            address token,
            uint liquidity,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline
        ) external returns (uint amountToken, uint amountETH);
        function removeLiquidityWithPermit(
            address tokenA,
            address tokenB,
            uint liquidity,
            uint amountAMin,
            uint amountBMin,
            address to,
            uint deadline,
            bool approveMax, uint8 v, bytes32 r, bytes32 s
        ) external returns (uint amountA, uint amountB);
        function removeLiquidityETHWithPermit(
            address token,
            uint liquidity,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline,
            bool approveMax, uint8 v, bytes32 r, bytes32 s
        ) external returns (uint amountToken, uint amountETH);
        function swapExactTokensForTokens(
            uint amountIn,
            uint amountOutMin,
            address[] calldata path,
            address to,
            uint deadline
        ) external returns (uint[] memory amounts);
        function swapTokensForExactTokens(
            uint amountOut,
            uint amountInMax,
            address[] calldata path,
            address to,
            uint deadline
        ) external returns (uint[] memory amounts);
        function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
            external
            payable
            returns (uint[] memory amounts);
        function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
            external
            returns (uint[] memory amounts);
        function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
            external
            returns (uint[] memory amounts);
        function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
            external
            payable
            returns (uint[] memory amounts);

        function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
        function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
        function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
        function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
        function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
    }

    interface IUniswapV2Router02 is IUniswapV2Router01 {
        function removeLiquidityETHSupportingFeeOnTransferTokens(
            address token,
            uint liquidity,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline
        ) external returns (uint amountETH);
        function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
            address token,
            uint liquidity,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline,
            bool approveMax, uint8 v, bytes32 r, bytes32 s
        ) external returns (uint amountETH);

        function swapExactTokensForTokensSupportingFeeOnTransferTokens(
            uint amountIn,
            uint amountOutMin,
            address[] calldata path,
            address to,
            uint deadline
        ) external;
        function swapExactETHForTokensSupportingFeeOnTransferTokens(
            uint amountOutMin,
            address[] calldata path,
            address to,
            uint deadline
        ) external payable;
        function swapExactTokensForETHSupportingFeeOnTransferTokens(
            uint amountIn,
            uint amountOutMin,
            address[] calldata path,
            address to,
            uint deadline
        ) external;
    }

    // Contract implementation
    contract KITKAT is Context, IERC20, Ownable {
        using SafeMath for uint256;
        using Address for address;

        mapping (address => uint256) private _rOwned;
        mapping (address => uint256) private _tOwned;
        mapping (address => mapping (address => uint256)) private _allowances;

        mapping (address => bool) private _isExcludedFromFee;

        mapping (address => bool) private _isExcluded;
        address[] private _excluded;
    
        uint256 private constant MAX = ~uint256(0);
        uint256 private _tTotal = 50000000 * 10**9;
        uint256 private _rTotal = (MAX - (MAX % _tTotal));
        uint256 private _tFeeTotal;

        string private _name = 'KITKAT Finance';
        string private _symbol = 'KITKAT';
        uint8 private _decimals = 9;
        
        // Tax and charity fees will start at 0 so we don't have a big impact when deploying to Uniswap
        // Charity wallet address is null but the method to set the address is exposed
        uint256 private _taxFee = 10; 
        uint256 private _charityFee = 10;
        uint256 private _previousTaxFee = _taxFee;
        uint256 private _previousCharityFee = _charityFee;

        address payable public _charityWalletAddress;
        address payable public _marketingWalletAddress;
        
        IUniswapV2Router02 public immutable uniswapV2Router;
        address public immutable uniswapV2Pair;

        bool inSwap = false;
        bool public swapEnabled = true;

        uint256 private _maxTxAmount = 50000000e9;
        // We will set a minimum amount of tokens to be swaped => 5M
        uint256 private _numOfTokensToExchangeForCharity = 10 * 10**9;

        event MinTokensBeforeSwapUpdated(uint256 minTokensBeforeSwap);
        event SwapEnabledUpdated(bool enabled);

        modifier lockTheSwap {
            inSwap = true;
            _;
            inSwap = false;
        }

        constructor (address payable charityWalletAddress) public {
            _charityWalletAddress = charityWalletAddress;
            _rOwned[_msgSender()] = _rTotal;

            IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D); // UniswapV2 for Ethereum network
            // Create a uniswap pair for this new token
            uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory())
                .createPair(address(this), _uniswapV2Router.WETH());

            // set the rest of the contract variables
            uniswapV2Router = _uniswapV2Router;

            // Exclude owner and this contract from fee
            _isExcludedFromFee[owner()] = true;
            _isExcludedFromFee[address(this)] = 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 view returns (uint8) {
            return _decimals;
        }

        function totalSupply() public view override returns (uint256) {
            return _tTotal;
        }

        function balanceOf(address account) public view override returns (uint256) {
            if (_isExcluded[account]) return _tOwned[account];
            return tokenFromReflection(_rOwned[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 increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
            _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
            return true;
        }

        function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
            _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
            return true;
        }

        function isExcluded(address account) public view returns (bool) {
            return _isExcluded[account];
        }

        function setExcludeFromFee(address account, bool excluded) external onlyOwner() {
            _isExcludedFromFee[account] = excluded;
        }

        function totalFees() public view returns (uint256) {
            return _tFeeTotal;
        }

        function deliver(uint256 tAmount) public {
            address sender = _msgSender();
            require(!_isExcluded[sender], "Excluded addresses cannot call this function");
            (uint256 rAmount,,,,,) = _getValues(tAmount);
            _rOwned[sender] = _rOwned[sender].sub(rAmount);
            _rTotal = _rTotal.sub(rAmount);
            _tFeeTotal = _tFeeTotal.add(tAmount);
        }

        function reflectionFromToken(uint256 tAmount, bool deductTransferFee) public view returns(uint256) {
            require(tAmount <= _tTotal, "Amount must be less than supply");
            if (!deductTransferFee) {
                (uint256 rAmount,,,,,) = _getValues(tAmount);
                return rAmount;
            } else {
                (,uint256 rTransferAmount,,,,) = _getValues(tAmount);
                return rTransferAmount;
            }
        }

        function tokenFromReflection(uint256 rAmount) public view returns(uint256) {
            require(rAmount <= _rTotal, "Amount must be less than total reflections");
            uint256 currentRate =  _getRate();
            return rAmount.div(currentRate);
        }

        function excludeAccount(address account) external onlyOwner() {
            require(account != 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D, 'We can not exclude Uniswap router.');
            require(!_isExcluded[account], "Account is already excluded");
            if(_rOwned[account] > 0) {
                _tOwned[account] = tokenFromReflection(_rOwned[account]);
            }
            _isExcluded[account] = true;
            _excluded.push(account);
        }

        function includeAccount(address account) external onlyOwner() {
            require(_isExcluded[account], "Account is already excluded");
            for (uint256 i = 0; i < _excluded.length; i++) {
                if (_excluded[i] == account) {
                    _excluded[i] = _excluded[_excluded.length - 1];
                    _tOwned[account] = 0;
                    _isExcluded[account] = false;
                    _excluded.pop();
                    break;
                }
            }
        }

        function removeAllFee() private {
            if(_taxFee == 0 && _charityFee == 0) return;
            
            _previousTaxFee = _taxFee;
            _previousCharityFee = _charityFee;
            
            _taxFee = 0;
            _charityFee = 0;
        }
    
        function restoreAllFee() private {
            _taxFee = _previousTaxFee;
            _charityFee = _previousCharityFee;
        }
    
        function isExcludedFromFee(address account) public view returns(bool) {
            return _isExcludedFromFee[account];
        }

        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 _transfer(address sender, address recipient, uint256 amount) private {
            require(sender != address(0), "ERC20: transfer from the zero address");
            require(recipient != address(0), "ERC20: transfer to the zero address");
            require(amount > 0, "Transfer amount must be greater than zero");
            
            if(sender != owner() && recipient != owner())
                require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount.");

            // is the token balance of this contract address over the min number of
            // tokens that we need to initiate a swap?
            // also, don't get caught in a circular charity event.
            // also, don't swap if sender is uniswap pair.
            uint256 contractTokenBalance = balanceOf(address(this));
            
            if(contractTokenBalance >= _maxTxAmount)
            {
                contractTokenBalance = _maxTxAmount;
            }
            
            bool overMinTokenBalance = contractTokenBalance >= _numOfTokensToExchangeForCharity;
            if (!inSwap && swapEnabled && overMinTokenBalance && sender != uniswapV2Pair) {
                // We need to swap the current tokens to ETH and send to the charity wallet
                swapTokensForEth(contractTokenBalance);
                
                uint256 contractETHBalance = address(this).balance;
                if(contractETHBalance > 0) {
                    sendETHToCharity(address(this).balance);
                }
            }
            
            //indicates if fee should be deducted from transfer
            bool takeFee = true;
            
            //if any account belongs to _isExcludedFromFee account then remove the fee
            if(_isExcludedFromFee[sender] || _isExcludedFromFee[recipient]){
                takeFee = false;
            }
            
            //transfer amount, it will take tax and charity fee
            _tokenTransfer(sender,recipient,amount,takeFee);
        }

        function swapTokensForEth(uint256 tokenAmount) private lockTheSwap{
            // generate the uniswap pair path of token -> weth
            address[] memory path = new address[](2);
            path[0] = address(this);
            path[1] = uniswapV2Router.WETH();

            _approve(address(this), address(uniswapV2Router), tokenAmount);

            // make the swap
            uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
                tokenAmount,
                0, // accept any amount of ETH
                path,
                address(this),
                block.timestamp
            );
        }
        
        function sendETHToCharity(uint256 amount) private {
            _charityWalletAddress.transfer(amount);
        }
        
        // We are exposing these functions to be able to manual swap and send
        // in case the token is highly valued and 5M becomes too much
        function manualSwap() external onlyOwner() {
            uint256 contractBalance = balanceOf(address(this));
            swapTokensForEth(contractBalance);
        }
        
        function manualSend() external onlyOwner() {
            uint256 contractETHBalance = address(this).balance;
            sendETHToCharity(contractETHBalance);
        }

        function setSwapEnabled(bool enabled) external onlyOwner(){
            swapEnabled = enabled;
        }
        
        function _tokenTransfer(address sender, address recipient, uint256 amount, bool takeFee) private {
            if(!takeFee)
                removeAllFee();

            if (_isExcluded[sender] && !_isExcluded[recipient]) {
                _transferFromExcluded(sender, recipient, amount);
            } else if (!_isExcluded[sender] && _isExcluded[recipient]) {
                _transferToExcluded(sender, recipient, amount);
            } else if (!_isExcluded[sender] && !_isExcluded[recipient]) {
                _transferStandard(sender, recipient, amount);
            } else if (_isExcluded[sender] && _isExcluded[recipient]) {
                _transferBothExcluded(sender, recipient, amount);
            } else {
                _transferStandard(sender, recipient, amount);
            }

            if(!takeFee)
                restoreAllFee();
        }

        function _transferStandard(address sender, address recipient, uint256 tAmount) private {
            (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tCharity) = _getValues(tAmount);
            _rOwned[sender] = _rOwned[sender].sub(rAmount);
            _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); 
            _takeCharity(tCharity); 
            _reflectFee(rFee, tFee);
            emit Transfer(sender, recipient, tTransferAmount);
        }

        function _transferToExcluded(address sender, address recipient, uint256 tAmount) private {
            (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tCharity) = _getValues(tAmount);
            _rOwned[sender] = _rOwned[sender].sub(rAmount);
            _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
            _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);    
            _takeCharity(tCharity);           
            _reflectFee(rFee, tFee);
            emit Transfer(sender, recipient, tTransferAmount);
        }

        function _transferFromExcluded(address sender, address recipient, uint256 tAmount) private {
            (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tCharity) = _getValues(tAmount);
            _tOwned[sender] = _tOwned[sender].sub(tAmount);
            _rOwned[sender] = _rOwned[sender].sub(rAmount);
            _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); 
            _takeCharity(tCharity);   
            _reflectFee(rFee, tFee);
            emit Transfer(sender, recipient, tTransferAmount);
        }

        function _transferBothExcluded(address sender, address recipient, uint256 tAmount) private {
            (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tCharity) = _getValues(tAmount);
            _tOwned[sender] = _tOwned[sender].sub(tAmount);
            _rOwned[sender] = _rOwned[sender].sub(rAmount);
            _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
            _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);   
            _takeCharity(tCharity);         
            _reflectFee(rFee, tFee);
            emit Transfer(sender, recipient, tTransferAmount);
        }

        function _takeCharity(uint256 tCharity) private {
            uint256 currentRate =  _getRate();
            uint256 rCharity = tCharity.mul(currentRate);
            _rOwned[address(this)] = _rOwned[address(this)].add(rCharity);
            if(_isExcluded[address(this)])
                _tOwned[address(this)] = _tOwned[address(this)].add(tCharity);
        }
        
        

        function _reflectFee(uint256 rFee, uint256 tFee) private {
            _rTotal = _rTotal.sub(rFee);
            _tFeeTotal = _tFeeTotal.add(tFee);
        }

         //to recieve ETH from uniswapV2Router when swaping
        receive() external payable {}

        function _getValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256, uint256, uint256) {
            (uint256 tTransferAmount, uint256 tFee, uint256 tCharity) = _getTValues(tAmount, _taxFee, _charityFee);
            uint256 currentRate =  _getRate();
            (uint256 rAmount, uint256 rTransferAmount, uint256 rFee) = _getRValues(tAmount, tFee, currentRate);
            return (rAmount, rTransferAmount, rFee, tTransferAmount, tFee, tCharity);
        }

        function _getTValues(uint256 tAmount, uint256 taxFee, uint256 charityFee) private pure returns (uint256, uint256, uint256) {
            uint256 tFee = tAmount.mul(taxFee).div(100);
            uint256 tCharity = tAmount.mul(charityFee).div(100);
            uint256 tTransferAmount = tAmount.sub(tFee).sub(tCharity);
            return (tTransferAmount, tFee, tCharity);
        }

        function _getRValues(uint256 tAmount, uint256 tFee, uint256 currentRate) private pure returns (uint256, uint256, uint256) {
            uint256 rAmount = tAmount.mul(currentRate);
            uint256 rFee = tFee.mul(currentRate);
            uint256 rTransferAmount = rAmount.sub(rFee);
            return (rAmount, rTransferAmount, rFee);
        }

        function _getRate() private view returns(uint256) {
            (uint256 rSupply, uint256 tSupply) = _getCurrentSupply();
            return rSupply.div(tSupply);
        }

        function _getCurrentSupply() private view returns(uint256, uint256) {
            uint256 rSupply = _rTotal;
            uint256 tSupply = _tTotal;      
            for (uint256 i = 0; i < _excluded.length; i++) {
                if (_rOwned[_excluded[i]] > rSupply || _tOwned[_excluded[i]] > tSupply) return (_rTotal, _tTotal);
                rSupply = rSupply.sub(_rOwned[_excluded[i]]);
                tSupply = tSupply.sub(_tOwned[_excluded[i]]);
            }
            if (rSupply < _rTotal.div(_tTotal)) return (_rTotal, _tTotal);
            return (rSupply, tSupply);
        }
        
        function _getTaxFee() private view returns(uint256) {
            return _taxFee;
        }

        function _getMaxTxAmount() private view returns(uint256) {
            return _maxTxAmount;
        }

        function _getETHBalance() public view returns(uint256 balance) {
            return address(this).balance;
        }
        
        function _setTaxFee(uint256 taxFee) external onlyOwner() {
            require(taxFee >= 1 && taxFee <= 10, 'taxFee should be in 1 - 10');
            _taxFee = taxFee;
        }

        function _setCharityFee(uint256 charityFee) external onlyOwner() {
            require(charityFee >= 1 && charityFee <= 26, 'charityFee should be in 1 - 11');
            _charityFee = charityFee;
        }
        
        function _setCharityWallet(address payable charityWalletAddress) external onlyOwner() {
            _charityWalletAddress = charityWalletAddress;
        }
        
        function _setMaxTxAmount(uint256 maxTxAmount) external onlyOwner() {
            require(maxTxAmount >= 100000000000000e9 , 'maxTxAmount should be greater than 100000000000000e9');
            _maxTxAmount = maxTxAmount;
        }
    }