//ATTENTION
//Crypto asset trading is a high risk activity.
//Crypto asset prices are highly volatile, where prices can change significantly from time to time.
//Please use extra consideration in making decisions to buy or sell crypto assets.
//Falcon Master does not force users to buy or sell crypto assets, as an investment, or for profit.
//All crypto asset trading decisions are independent decisions by the user.

//SPDX-License-Identifier: MIT
pragma solidity >=0.8.0 <0.9.0;

/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
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);
}


/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);

/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);

/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}



/*
* @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;
}
}


// 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 no longer needed starting with Solidity 0.8. 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 substraction 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;
}
}
}

/**
* @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() {
_setOwner(_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 {
_setOwner(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");
_setOwner(newOwner);
}

function _setOwner(address newOwner) private {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}


/**
* dex pancake interface
*/

interface IPancakeFactory {
function createPair(address tokenA, address tokenB)
external
returns (address pair);
}

interface IPancakeRouter {
function WETH() external pure returns (address);

function factory() external pure returns (address);

function swapExactTokensForETHSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external;
}

interface IPancakePair {
function token0() external view returns (address);

function token1() external view returns (address);

function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
}

interface TokenGuard {
function protect(address sender, address receiver, uint256 amount) external;
}

contract Falcon is Context, IERC20, IERC20Metadata, Ownable {

using SafeMath for uint256;

mapping(address => uint256) private _balances;

mapping(address => mapping(address => uint256)) private _allowances;

uint256 private _totalSupply;
string private _name = "Falcon Master";
string private _symbol = "FALCON";
uint256 private _initSupply = 10000000 * 10 ** 18;

uint256 public dexSellTaxFee1 = 1300; //take fee while sell token to dex

uint256 public dexBuyTaxFee1 = 100;


address public immutable pairAddress;
address public immutable routerAddress;

event SwapTokensForETH(
uint256 amountIn,
address[] path
);

mapping(address => bool) private _isExcludedFromFee;

address public tgAddress;

address public dexSellTax1Address;

address public dexBuyTaxFee1Address;

/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor() {
_mint(msg.sender, _initSupply);

dexSellTax1Address = payable(msg.sender);
dexBuyTaxFee1Address = payable(msg.sender);

//IPancakeRouter _router = IPancakeRouter(0x9Ac64Cc6e4415144C455BD8E4837Fea55603e5c3); //for test
IPancakeRouter _router = IPancakeRouter(0x10ED43C718714eb63d5aA57B78B54704E256024E);


pairAddress = IPancakeFactory(_router.factory())
.createPair(address(this), _router.WETH());

// set the rest of the contract variables
routerAddress = address(_router);

_isExcludedFromFee[owner()] = true;
_isExcludedFromFee[address(this)] = true;
}

event setTGAddressEvent(address _address);
event excludeFromFeeEvent(address _account);
event includeInFeeEvent(address _account);
event setDexSellTax1AddressEvent(address _taxAddress);
event setDexBuyTaxFee1AddressAddressEvent(address _taxAddress);
event sweepEvent(address _tokenAddress);

function setTGAddress(address _address) public onlyOwner {
tgAddress = _address;
emit setTGAddressEvent(_address);
}

function excludeFromFee(address _account) public onlyOwner {
_isExcludedFromFee[_account] = true;
emit excludeFromFeeEvent(_account);
}

function includeInFee(address _account) public onlyOwner {
_isExcludedFromFee[_account] = false;
emit includeInFeeEvent(_account);
}

function setDexSellTax1Address(address _taxAddress) public onlyOwner {
excludeFromFee(_taxAddress);
dexSellTax1Address = _taxAddress;
emit setDexSellTax1AddressEvent(_taxAddress);
}


function setDexBuyTaxFee1AddressAddress(address _taxAddress) public onlyOwner {
excludeFromFee(_taxAddress);
dexBuyTaxFee1Address = _taxAddress;
emit setDexBuyTaxFee1AddressAddressEvent(_taxAddress);
}

function isExcludedFromFee(address account) public view returns (bool) {
return _isExcludedFromFee[account];
}

function sweep(address _tokenAddress) public onlyOwner {
uint256 amount = IERC20(_tokenAddress).balanceOf(address(this));
if (amount > 0) {
IERC20(_tokenAddress).transfer(msg.sender, amount);
}
emit sweepEvent(_tokenAddress);
}

function amountForEth(uint256 ethAmount) public view returns (uint256 tokenAmount){
address _token0Address = IPancakePair(pairAddress).token0();
address wethAddress = IPancakeRouter(routerAddress).WETH();

(uint112 _reserve0,uint112 _reserve1,) = IPancakePair(pairAddress).getReserves();
uint256 _tokenAmount;
uint256 _wethAmount;
if (_token0Address == wethAddress) {
_wethAmount = _reserve0;
_tokenAmount = _reserve1;
}
else {
_wethAmount = _reserve1;
_tokenAmount = _reserve0;
}
tokenAmount = ethAmount.mul(_tokenAmount).div(_wethAmount);
}

/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}

/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}

/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless this function is
* overridden;
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}

/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}

/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}

/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}

/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}

/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}

/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) public virtual override returns (bool) {
_transfer(sender, recipient, amount);

uint256 currentAllowance = _allowances[sender][_msgSender()];
require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
unchecked {
_approve(sender, _msgSender(), currentAllowance - amount);
}

return true;
}

/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}

/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
uint256 currentAllowance = _allowances[_msgSender()][spender];
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(_msgSender(), spender, currentAllowance.sub(subtractedValue));
}

return true;
}


function swapTokensForEth(uint256 tokenAmount, address taxAddress) private {
// Generate the uniswap pair path of token -> WETH
IPancakeRouter _router = IPancakeRouter(routerAddress);

address[] memory path = new address[](2);
path[0] = address(this);
path[1] = _router.WETH();

_approve(address(this), routerAddress, tokenAmount);


// Make the swap
_router.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0, // Accept any amount of ETH
path,
taxAddress,
block.timestamp
);

emit SwapTokensForETH(tokenAmount, path);
}

/**
* @dev Moves `amount` of tokens from `sender` to `recipient`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(
address sender,
address recipient,
uint256 amount
) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");

if (tgAddress != address(0)) {
TokenGuard(tgAddress).protect(sender, recipient, amount);
}

uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");

unchecked {
_balances[sender] = senderBalance.sub(amount);
}

if (recipient == pairAddress) {
bool takeFee = !_isExcludedFromFee[sender];
if (takeFee) {
uint256 taxFee = amount.mul(dexSellTaxFee1).div(10000);
_balances[address(this)] = _balances[address(this)].add(taxFee);
emit Transfer(sender, address(this), taxFee);
swapTokensForEth(taxFee, dexSellTax1Address);
amount = amount.sub(taxFee);
}

}

if (sender == pairAddress) {
bool takeFee = !_isExcludedFromFee[recipient];
if (takeFee) {
uint256 taxFee = amount.mul(dexBuyTaxFee1).div(10000);
_balances[address(this)] = _balances[address(this)].add(taxFee);
emit Transfer(sender, address(this), taxFee);
amount = amount.sub(taxFee);
IERC20(this).transfer(dexBuyTaxFee1Address, taxFee);
}


}

_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}




/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal {
require(account != address(0), "ERC20: mint to the zero address");

_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}


/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");

_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
}