Contract Address Details

// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;
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) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        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) {
        // 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) {
        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) {
        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) {
        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) {
        require(b <= a, "SafeMath: subtraction overflow");
        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) {
        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, reverting 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) {
        require(b > 0, "SafeMath: division by zero");
        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) {
        require(b > 0, "SafeMath: modulo by zero");
        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) {
        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.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * 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);
        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) {
        require(b > 0, errorMessage);
        return a % b;
    }
}
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;
    }
}
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 () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

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

contract Operator is Context, Ownable {
    address private _operator;

    event OperatorTransferred(address indexed previousOperator, address indexed newOperator);

    constructor() internal {
        _operator = _msgSender();
        emit OperatorTransferred(address(0), _operator);
    }

    function operator() public view returns (address) {
        return _operator;
    }

    modifier onlyOperator() {
        require(_operator == msg.sender, "operator: caller is not the operator");
        _;
    }

    function isOperator() public view returns (bool) {
        return _msgSender() == _operator;
    }

    function transferOperator(address newOperator_) public onlyOwner {
        _transferOperator(newOperator_);
    }

    function _transferOperator(address newOperator_) internal {
        require(newOperator_ != address(0), "operator: zero address given for new operator");
        emit OperatorTransferred(address(0), newOperator_);
        _operator = newOperator_;
    }
}
interface ITaxable {
    function setTaxTiersTwap(uint8 _index, uint256 _value) external returns (bool);

    function setTaxTiersRate(uint8 _index, uint256 _value) external returns (bool);

    function enableAutoCalculateTax() external;

    function disableAutoCalculateTax() external;

    function setTaxCollectorAddress(address _taxCollectorAddress) external;

    function isAddressExcluded(address _address) external returns (bool);

    function setTaxRate(uint256 _taxRate) external;

    function setBurnThreshold(uint256 _burnThreshold) external;

    function excludeAddress(address _address) external returns (bool);

    function includeAddress(address _address) external returns (bool);

    function setNavaOracle(address _navaOracle) external;

    function setTaxOffice(address _taxOffice) external;

    function taxRate() external view returns (uint256);
}
interface IUniswapV2Router {
    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);

    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;
}
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);
}

contract TaxOfficeV2 is Operator {
    using SafeMath for uint256;

    address public nava = address(0x46D741b89102815710efeA3051291E64Ff49C228);
    address public wftm = address(0x2545AF3D8b11e295bB7aEdD5826021AB54F71630);
    address public uniRouter = address(0x1EEF778fC06C427ded93560aF37EfDc534C9c854);

    mapping(address => bool) public taxExclusionEnabled;

    function setTaxTiersTwap(uint8 _index, uint256 _value) public onlyOperator returns (bool) {
        return ITaxable(nava).setTaxTiersTwap(_index, _value);
    }

    function setTaxTiersRate(uint8 _index, uint256 _value) public onlyOperator returns (bool) {
        return ITaxable(nava).setTaxTiersRate(_index, _value);
    }

    function enableAutoCalculateTax() public onlyOperator {
        ITaxable(nava).enableAutoCalculateTax();
    }

    function disableAutoCalculateTax() public onlyOperator {
        ITaxable(nava).disableAutoCalculateTax();
    }

    function setTaxRate(uint256 _taxRate) public onlyOperator {
        ITaxable(nava).setTaxRate(_taxRate);
    }

    function setBurnThreshold(uint256 _burnThreshold) public onlyOperator {
        ITaxable(nava).setBurnThreshold(_burnThreshold);
    }

    function setTaxCollectorAddress(address _taxCollectorAddress) public onlyOperator {
        ITaxable(nava).setTaxCollectorAddress(_taxCollectorAddress);
    }

    function excludeAddressFromTax(address _address) external onlyOperator returns (bool) {
        return _excludeAddressFromTax(_address);
    }

    function _excludeAddressFromTax(address _address) private returns (bool) {
        if (!ITaxable(nava).isAddressExcluded(_address)) {
            return ITaxable(nava).excludeAddress(_address);
        }
    }

    function includeAddressInTax(address _address) external onlyOperator returns (bool) {
        return _includeAddressInTax(_address);
    }

    function _includeAddressInTax(address _address) private returns (bool) {
        if (ITaxable(nava).isAddressExcluded(_address)) {
            return ITaxable(nava).includeAddress(_address);
        }
    }

    function taxRate() external view returns (uint256) {
        return ITaxable(nava).taxRate();
    }

    function addLiquidityTaxFree(
        address token,
        uint256 amtNava,
        uint256 amtToken,
        uint256 amtNavaMin,
        uint256 amtTokenMin
    )
        external
        returns (
            uint256,
            uint256,
            uint256
        )
    {
        require(amtNava != 0 && amtToken != 0, "amounts can't be 0");
        _excludeAddressFromTax(msg.sender);

        IERC20(nava).transferFrom(msg.sender, address(this), amtNava);
        IERC20(token).transferFrom(msg.sender, address(this), amtToken);
        _approveTokenIfNeeded(nava, uniRouter);
        _approveTokenIfNeeded(token, uniRouter);

        _includeAddressInTax(msg.sender);

        uint256 resultAmtNava;
        uint256 resultAmtToken;
        uint256 liquidity;
        (resultAmtNava, resultAmtToken, liquidity) = IUniswapV2Router(uniRouter).addLiquidity(
            nava,
            token,
            amtNava,
            amtToken,
            amtNavaMin,
            amtTokenMin,
            msg.sender,
            block.timestamp
        );

        if(amtNava.sub(resultAmtNava) > 0) {
            IERC20(nava).transfer(msg.sender, amtNava.sub(resultAmtNava));
        }
        if(amtToken.sub(resultAmtToken) > 0) {
            IERC20(token).transfer(msg.sender, amtToken.sub(resultAmtToken));
        }
        return (resultAmtNava, resultAmtToken, liquidity);
    }

    function addLiquidityETHTaxFree(
        uint256 amtNava,
        uint256 amtNavaMin,
        uint256 amtFtmMin
    )
        external
        payable
        returns (
            uint256,
            uint256,
            uint256
        )
    {
        require(amtNava != 0 && msg.value != 0, "amounts can't be 0");
        _excludeAddressFromTax(msg.sender);

        IERC20(nava).transferFrom(msg.sender, address(this), amtNava);
        _approveTokenIfNeeded(nava, uniRouter);

        _includeAddressInTax(msg.sender);

        uint256 resultAmtNava;
        uint256 resultAmtFtm;
        uint256 liquidity;
        (resultAmtNava, resultAmtFtm, liquidity) = IUniswapV2Router(uniRouter).addLiquidityETH{value: msg.value}(
            nava,
            amtNava,
            amtNavaMin,
            amtFtmMin,
            msg.sender,
            block.timestamp
        );

        if(amtNava.sub(resultAmtNava) > 0) {
            IERC20(nava).transfer(msg.sender, amtNava.sub(resultAmtNava));
        }
        return (resultAmtNava, resultAmtFtm, liquidity);
    }

    function setTaxableNavaOracle(address _navaOracle) external onlyOperator {
        ITaxable(nava).setNavaOracle(_navaOracle);
    }

    function transferTaxOffice(address _newTaxOffice) external onlyOperator {
        ITaxable(nava).setTaxOffice(_newTaxOffice);
    }

    function taxFreeTransferFrom(
        address _sender,
        address _recipient,
        uint256 _amt
    ) external {
        require(taxExclusionEnabled[msg.sender], "Address not approved for tax free transfers");
        _excludeAddressFromTax(_sender);
        IERC20(nava).transferFrom(_sender, _recipient, _amt);
        _includeAddressInTax(_sender);
    }

    function setTaxExclusionForAddress(address _address, bool _excluded) external onlyOperator {
        taxExclusionEnabled[_address] = _excluded;
    }

    function _approveTokenIfNeeded(address _token, address _router) private {
        if (IERC20(_token).allowance(address(this), _router) == 0) {
            IERC20(_token).approve(_router, type(uint256).max);
        }
    }
}