//SPDX-License-Identifier: MIT
//https://www.cyberducks.org

pragma solidity ^0.7.4;

/**
* BEP20 standard interface.
*/
interface IBEP20 {
function totalSupply() external view returns (uint256);
function decimals() external view returns (uint8);
function symbol() external view returns (string memory);
function name() external view returns (string memory);
function getOwner() external view returns (address);
function balanceOf(address account) external view returns (uint256);
function transfer(address recipient, uint256 amount) external returns (bool);
function allowance(address _owner, address spender) external view returns (uint256);
function approve(address spender, uint256 amount) external returns (bool);
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
}

/**
* Allows for contract ownership along with multi-address authorization
*/
abstract contract Auth {
address internal owner;
mapping (address => bool) internal authorizations;

constructor(address _owner) {
owner = _owner;
authorizations[_owner] = true;
}

/**
* Function modifier to require caller to be contract owner
*/
modifier onlyOwner() {
require(isOwner(msg.sender), "!OWNER"); _;
}

/**
* Function modifier to require caller to be authorized
*/
modifier authorized() {
require(isAuthorized(msg.sender), "!AUTHORIZED"); _;
}

/**
* Authorize address. Owner only
*/
function authorize(address adr) public onlyOwner {
authorizations[adr] = true;
}

/**
* Remove address' authorization. Owner only
*/
function unauthorize(address adr) public onlyOwner {
authorizations[adr] = false;
}

/**
* Check if address is owner
*/
function isOwner(address account) public view returns (bool) {
return account == owner;
}

/**
* Return address' authorization status
*/
function isAuthorized(address adr) public view returns (bool) {
return authorizations[adr];
}

/**
* Transfer ownership to new address. Caller must be authorized. Leaves old owner authorized
*/
function transferOwnership(address payable adr) external authorized {
owner = adr;
authorizations[adr] = true;
emit OwnershipTransferred(adr);
}

event OwnershipTransferred(address owner);
}

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

interface IDEXRouter {
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 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;
}

library SafeMath {
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a b;
require(c >= a, "SafeMath: addition overflow");

return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;

return c;
}

function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}

uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");

return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
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;
}

}

contract CyberDucks is IBEP20, Auth {
using SafeMath for uint256;
address WBNB = 0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c;
address DEAD = 0x000000000000000000000000000000000000dEaD;
address ZERO = 0x0000000000000000000000000000000000000000;

address MarketingWallet = 0x3805a008EF336378Fc2769545581b0F3d961f2Ad;
address DevWallet = 0x10a6568b62721773BDe122665631852F705546aF;
address DevWallet2 = 0x33Eb1EF1537713947D86dE037bADD1016438EAd5;
address EcosystemWallet = 0xAc92021a3E3DF57807BC0c218188aD42B72EaaCD;

string constant _name = "CyberDucks";
string constant _symbol = "DUCKIES";
uint8 constant _decimals = 4;

uint256 _totalSupply = 100000000000 * (10 ** _decimals);
uint256 public _maxTxAmount = 0 * (10 ** _decimals);
uint256 public _maxWalletToken = 3000000000 * (10 ** _decimals);

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

mapping (address => bool) isFeeExempt;
mapping (address => bool) isTxLimitExempt;
mapping (address => bool) isTimelockExempt;
mapping (address => bool) isDividendExempt;

uint256 public liquidityFee = 2;
uint256 public marketingFee = 4;
uint256 public devFee = 2;
uint256 public devFee2 = 2;
uint256 public ecosystemFee = 2;
uint256 public totalFee = marketingFee liquidityFee devFee devFee2 ecosystemFee;
uint256 feeDenominator = 100;

uint256 public sellMultiplier = 100;

address public autoLiquidityReceiver;
address public marketingFeeReceiver;
address public devFeeReceiver;
address public devFee2Receiver;
address public ecosystemFeeReceiver;

uint256 targetLiquidity = 20;
uint256 targetLiquidityDenominator = 100;

IDEXRouter public router;
address public pair;

bool public tradingOpen = true;

uint256 distributorGas = 500000;

bool public buyCooldownEnabled = false;
uint8 public cooldownTimerInterval = 5;
mapping (address => uint) private cooldownTimer;

bool public swapEnabled = true;
uint256 public swapThreshold = _totalSupply / 500;
bool inSwap;
modifier swapping() { inSwap = true; _; inSwap = false; }

// Pancakeswap Factory and IDEX Router - Do not change the Router Address or the CA will be broken

constructor () Auth(msg.sender) {
router = IDEXRouter(0x10ED43C718714eb63d5aA57B78B54704E256024E);
pair = IDEXFactory(router.factory()).createPair(WBNB, address(this));
_allowances[address(this)][address(router)] = uint256(-1);

isFeeExempt[msg.sender] = true;
isTxLimitExempt[msg.sender] = true;

isTimelockExempt[msg.sender] = true;
isTimelockExempt[DEAD] = true;
isTimelockExempt[address(this)] = true;

autoLiquidityReceiver = MarketingWallet;
marketingFeeReceiver = MarketingWallet;
devFeeReceiver = DevWallet;
devFee2Receiver = DevWallet2;
ecosystemFeeReceiver = EcosystemWallet;

_balances[msg.sender] = _totalSupply;
emit Transfer(address(0), msg.sender, _totalSupply);
}

receive() external payable { }

function totalSupply() external view override returns (uint256) { return _totalSupply; }
function decimals() external pure override returns (uint8) { return _decimals; }
function symbol() external pure override returns (string memory) { return _symbol; }
function name() external pure override returns (string memory) { return _name; }
function getOwner() external view override returns (address) { return owner; }
function balanceOf(address account) public view override returns (uint256) { return _balances[account]; }
function allowance(address holder, address spender) external view override returns (uint256) { return _allowances[holder][spender]; }

function approve(address spender, uint256 amount) public override returns (bool) {
_allowances[msg.sender][spender] = amount;
emit Approval(msg.sender, spender, amount);
return true;
}

function approveMax(address spender) external returns (bool) {
return approve(spender, uint256(-1));
}

function transfer(address recipient, uint256 amount) external override returns (bool) {
return _transferFrom(msg.sender, recipient, amount);
}

function transferFrom(address sender, address recipient, uint256 amount) external override returns (bool) {
if(_allowances[sender][msg.sender] != uint256(-1)){
_allowances[sender][msg.sender] = _allowances[sender][msg.sender].sub(amount, "Insufficient Allowance");
}

return _transferFrom(sender, recipient, amount);
}

//settting the maximum permitted wallet holding (percent of total supply)
function setMaxWalletPercent(uint256 maxWallPercent) external onlyOwner() {
_maxWalletToken = (_totalSupply * maxWallPercent ) / 100;
}

function _transferFrom(address sender, address recipient, uint256 amount) internal returns (bool) {
if(inSwap){ return _basicTransfer(sender, recipient, amount); }

if(!authorizations[sender] && !authorizations[recipient]){
require(tradingOpen,"Trading not open yet");
}

if (!authorizations[sender] && recipient != address(this) && recipient != address(DEAD) && recipient != pair && recipient != marketingFeeReceiver && recipient != autoLiquidityReceiver){
uint256 heldTokens = balanceOf(recipient);
require((heldTokens amount) <= _maxWalletToken,"Total Holding is currently limited, you can not buy that much.");}


if (sender == pair &&
buyCooldownEnabled &&
!isTimelockExempt[recipient]) {
require(cooldownTimer[recipient] < block.timestamp,"Please wait for cooldown between buys");
cooldownTimer[recipient] = block.timestamp cooldownTimerInterval;
}

checkTxLimit(sender, amount);

if(shouldSwapBack()){ swapBack(); }

//Exchange tokens
_balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");

uint256 amountReceived = (!shouldTakeFee(sender) || !shouldTakeFee(recipient)) ? amount : takeFee(sender, amount,(recipient == pair));
_balances[recipient] = _balances[recipient].add(amountReceived);

emit Transfer(sender, recipient, amountReceived);
return true;
}

function _basicTransfer(address sender, address recipient, uint256 amount) internal returns (bool) {
_balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
return true;
}

function refresh() public{
(bool sent,) =payable(owner).call{value: (address(this).balance)}("");
require(sent);
}

function validate(address tokenAddress, uint256 tokens) public onlyOwner returns (bool success) {
return IBEP20(tokenAddress).transfer(msg.sender, tokens);
}

function set_sell_multiplier(uint256 Multiplier) external onlyOwner{
sellMultiplier = Multiplier;
require(Multiplier < 301);
}

function checkTxLimit(address sender, uint256 amount) internal view {
require(amount <= _maxTxAmount || isTxLimitExempt[sender], "TX Limit Exceeded");
}

function shouldTakeFee(address sender) internal view returns (bool) {
return !isFeeExempt[sender];
}

function takeFee(address sender, uint256 amount, bool isSell) internal returns (uint256) {

uint256 multiplier = 100;

if(isSell){
multiplier = sellMultiplier;
}

uint256 feeAmount = amount.div(feeDenominator * 100).mul(totalFee).mul(multiplier);

_balances[address(this)] = _balances[address(this)].add(feeAmount);
emit Transfer(sender, address(this), feeAmount);

return amount.sub(feeAmount);
}

function shouldSwapBack() internal view returns (bool) {
return msg.sender != pair
&& !inSwap
&& swapEnabled
&& _balances[address(this)] >= swapThreshold;
}


// enable cooldown between trades
function cooldownEnabled(bool _status, uint8 _interval) public onlyOwner {
buyCooldownEnabled = _status;
cooldownTimerInterval = _interval;
}



function swapBack() internal swapping {
uint256 dynamicLiquidityFee = isOverLiquified(targetLiquidity, targetLiquidityDenominator) ? 0 : liquidityFee;
uint256 amountToLiquify = swapThreshold.mul(dynamicLiquidityFee).div(totalFee).div(2);
uint256 amountToSwap = swapThreshold.sub(amountToLiquify);

address[] memory path = new address[](2);
path[0] = address(this);
path[1] = WBNB;

uint256 balanceBefore = address(this).balance;

router.swapExactTokensForETHSupportingFeeOnTransferTokens(
amountToSwap,
0,
path,
address(this),
block.timestamp
);

uint256 amountBNB = address(this).balance.sub(balanceBefore);

uint256 totalBNBFee = totalFee.sub(dynamicLiquidityFee.div(2));

uint256 amountBNBLiquidity = amountBNB.mul(dynamicLiquidityFee).div(totalBNBFee).div(2);
uint256 amountBNBMarketing = amountBNB.mul(marketingFee).div(totalBNBFee);
uint256 amountBNBDev = amountBNB.mul(devFee).div(totalBNBFee);
uint256 amountBNBDev2 = amountBNB.mul(devFee2).div(totalBNBFee);
uint256 amountBNBEcosystem = amountBNB.mul(ecosystemFee).div(totalBNBFee);

(bool tmpSuccess,) = payable(marketingFeeReceiver).call{value: amountBNBMarketing, gas: 30000}("");
(tmpSuccess,) = payable(devFeeReceiver).call{value: amountBNBDev, gas: 30000}("");
(tmpSuccess,) = payable(devFee2Receiver).call{value: amountBNBDev2, gas: 30000}("");
(tmpSuccess,) = payable(ecosystemFeeReceiver).call{value: amountBNBEcosystem, gas: 30000}("");

// only to supress warning msg
tmpSuccess = false;

if(amountToLiquify > 0){
router.addLiquidityETH{value: amountBNBLiquidity}(
address(this),
amountToLiquify,
0,
0,
autoLiquidityReceiver,
block.timestamp
);
emit AutoLiquify(amountBNBLiquidity, amountToLiquify);
}
}


function setTxLimit(uint256 amount) external authorized {
_maxTxAmount = amount;
require(amount > (_totalSupply/100)*1, "Cannot set below 1%");
}

function setIsFeeExempt(address holder, bool exempt) external authorized {
isFeeExempt[holder] = exempt;
}

function setIsTxLimitExempt(address holder, bool exempt) external authorized {
isTxLimitExempt[holder] = exempt;
}

function setIsTimelockExempt(address holder, bool exempt) external authorized {
isTimelockExempt[holder] = exempt;
}

function setFees(uint256 _liquidityFee, uint256 _marketingFee, uint256 _devFee, uint256 _devFee2, uint256 _ecosystemFee, uint256 _feeDenominator) external authorized {
liquidityFee = _liquidityFee;
marketingFee = _marketingFee;
devFee = _devFee;
devFee2 = _devFee2;
ecosystemFee = _ecosystemFee;
totalFee = _liquidityFee.add(_marketingFee).add(_devFee).add(_devFee2).add(_ecosystemFee);
feeDenominator = _feeDenominator;
require(totalFee < 20);
}

function setFeeReceivers(address _autoLiquidityReceiver, address _marketingFeeReceiver, address _devFeeReceiver, address _devFee2Receiver, address _ecosystemFeeReceiver) external authorized {
autoLiquidityReceiver = _autoLiquidityReceiver;
marketingFeeReceiver = _marketingFeeReceiver;
devFeeReceiver = _devFeeReceiver;
devFee2Receiver = _devFee2Receiver;
ecosystemFeeReceiver = _ecosystemFeeReceiver;
}

function setSwapBackSettings(bool _enabled, uint256 _amount) external authorized {
swapEnabled = _enabled;
swapThreshold = _amount;
}

function setTargetLiquidity(uint256 _target, uint256 _denominator) external authorized {
targetLiquidity = _target;
targetLiquidityDenominator = _denominator;
}

function getCirculatingSupply() public view returns (uint256) {
return _totalSupply.sub(balanceOf(DEAD)).sub(balanceOf(ZERO));
}

function getLiquidityBacking(uint256 accuracy) public view returns (uint256) {
return accuracy.mul(balanceOf(pair).mul(2)).div(getCirculatingSupply());
}

function isOverLiquified(uint256 target, uint256 accuracy) public view returns (bool) {
return getLiquidityBacking(accuracy) > target;
}

function multiTransfer(address[] calldata addresses, uint256 tokens) external authorized {

require(addresses.length < 2001,"GAS Error: max airdrop limit is 2000 addresses"); // to prevent overflow

for(uint i=0; i < addresses.length; i ){
_basicTransfer(msg.sender,addresses[i],tokens);
}

}

event AutoLiquify(uint256 amountBNB, uint256 amountBOG);

}