/**
//
OCTOPUS
Telegram: https://t.me/OctopusBsc
Twitter: https://twitter.com/OctopusBsc
Website:https://www.octopus.com.de

*/


// SPDX-License-Identifier: MIT



pragma solidity ^0.8.4;

abstract contract Context {
function _msgSender() internal view virtual returns (address payable) {
return payable(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 {

function totalSupply() external view returns (uint256);
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);


}


library Address {

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);
}

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");
}


function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}

function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
return _functionCallWithValue(target, data, 0, errorMessage);
}

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");
}

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");

(bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
if (success) {
return returndata;
} else {

if (returndata.length > 0) {
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}

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);
}

contract ERC20 is Context, IERC20, IERC20Metadata {
mapping (address => uint256) private _balances;

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

uint256 private _totalSupply;

string private _name;
string private _symbol;

/**
* @dev Sets the values for {name} and {symbol}.
*
* The defaut 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 (string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}

/**
* @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");
_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] 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");
_approve(_msgSender(), spender, currentAllowance - subtractedValue);

return true;
}

/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is 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");

_beforeTokenTransfer(sender, recipient, amount);

uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
_balances[sender] = senderBalance - amount;
_balances[recipient] = 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:
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");

_beforeTokenTransfer(address(0), account, amount);

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

/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");

_beforeTokenTransfer(account, address(0), amount);

uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
_balances[account] = accountBalance - amount;
_totalSupply -= amount;

emit Transfer(account, address(0), 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);
}

/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be to transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}

contract Ownable is Context {
address private _owner;


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

constructor () {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}

function owner() public view returns (address) {
return _owner;
}

modifier onlyOwner() {
require(_owner == _msgSender(), "Ownable: caller is not the owner");
_;
}

function renounceOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}

function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}

}

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

interface IRouter {
function factory() external pure returns (address);
function WETH() external pure returns (address);
function addLiquidityETH(
address token,
uint amountTokenDesired,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external payable returns (uint amountToken, uint amountETH, uint liquidity);

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


contract Octopus is ERC20, Ownable {
using Address for address;


IRouter public router;
address public pair;

bool private _liquidityMutex = false;
uint256 public _tokenLiquidityThreshold = 1000e18;
bool public ProvidingLiquidity = false;

uint16 public feeliq;
uint16 public feeliq_buy = 6;
uint16 public feeliq_sell = 6;
uint16 constant internal DIV = 100;

mapping (address => bool) public exemptFee;

event LiquidityProvided(uint256 tokenAmount, uint256 nativeAmount, uint256 exchangeAmount);
event LiquidityProvisionStateChanged(bool newState);
event LiquidityThresholdUpdated(uint256 newThreshold);


modifier mutexLock() {
if (!_liquidityMutex) {
_liquidityMutex = true;
_;
_liquidityMutex = false;
}
}

constructor() ERC20("Octopus", "$OCTO") {
_mint(msg.sender, 1e9 * 10 ** decimals());
exemptFee[msg.sender] = true;

IRouter _router = IRouter(0x10ED43C718714eb63d5aA57B78B54704E256024E);
// Create a koffeeSwap pair for this new token
address _pair = IFactory(_router.factory())
.createPair(address(this), _router.WETH());

router = _router;
pair = _pair;

exemptFee[address(this)] = true;
}


function _transfer(address sender, address recipient, uint256 amount) internal override {

//calculate fee
if(recipient == pair){
feeliq = feeliq_sell;
}
else{
feeliq = feeliq_buy;
}
uint256 fee = amount * feeliq / DIV;

//set fee to zero if fees in contract are handled or exempted
if (_liquidityMutex || exemptFee[sender] || exemptFee[recipient]) fee = 0;

//send fees if threshold has been reached
//don't do this on buys, breaks swap
if (ProvidingLiquidity && sender != pair) handle_fees();

//rest to recipient
super._transfer(sender, recipient, amount - fee);

//send the fee to the contract
if (fee > 0) {
super._transfer(sender, address(this), fee);
}

}

function handle_fees() private mutexLock {
uint256 contractBalance = balanceOf(address(this));
if (contractBalance >= _tokenLiquidityThreshold) {

//calculate how many tokens we need to exchange
uint256 exchange = contractBalance / 2;
uint256 exchangeOtherHalf = exchange;

uint256 initBalance = address(this).balance;
swapTokensForBNB(exchange);
uint256 bnbBalance = address(this).balance - initBalance;

addLiquidity(exchangeOtherHalf, bnbBalance);
}
}


function swapTokensForBNB(uint256 tokenAmount) private {
// generate the uniswap pair path of token -> weth
address[] memory path = new address[](2);
path[0] = address(this);
path[1] = router.WETH();

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

// make the swap
router.swapExactTokensForETHSupportingFeeOnTransferTokens(tokenAmount, 0, path, address(this), block.timestamp);

}

function addLiquidity(uint256 tokenAmount, uint256 bnbAmount) private {
// approve token transfer to cover all possible scenarios
_approve(address(this), address(router), tokenAmount);

// add the liquidity
router.addLiquidityETH{value: bnbAmount}(
address(this),
tokenAmount,
0, // slippage is unavoidable
0, // slippage is unavoidable
address(0),
block.timestamp
);
}

function changeLiquidityProvide(bool state) external onlyOwner {
//change liquidity providing state
ProvidingLiquidity = state;
emit LiquidityProvisionStateChanged(state);
}

function changeLiquidityTreshhold(uint256 new_amount) external onlyOwner {
//change the treshhold
_tokenLiquidityThreshold = new_amount;
emit LiquidityThresholdUpdated(new_amount);
}

function changeFees(uint16 _feeliq_buy, uint16 _feeliq_sell) external onlyOwner{
feeliq_buy = _feeliq_buy;
feeliq_sell = _feeliq_sell;
}


function updateExemptFee(address _address, bool state) external onlyOwner returns (bool) {
exemptFee[_address] = state;
return true;
}


// fallbacks
receive() external payable {}

}