contract ERC20 is Context, IERC20, IERC20Metadata, Ownable {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) private _liquidityHolders;
    mapping (address => bool) private _isBlacklisted;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    uint256 private startingSupply = 1_000_000;
    uint256 private _total = startingSupply * 10**18;

    // UNI ROUTER
    address private _routerAddress = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;

    address public burnAddress = 0x000000000000000000000000000000000000dEaD;

    IUniswapV2Router02 public dexRouter;
    address private lpPair;

    // Max TX amount is 1% of the total supply.
    uint256 private maxTxPercent = 1; // Less fields to edit
    uint256 private maxTxDivisor = 100;
    uint256 private _maxTxAmount = (_total * maxTxPercent) / maxTxDivisor;
    uint256 private _previousMaxTxAmount = _maxTxAmount;
    uint256 public maxTxAmountUI = (startingSupply * maxTxPercent) / maxTxDivisor; // Actual amount for UI's
    // Maximum wallet size is 2% of the total supply.
    uint256 private maxWalletPercent = 2; // Less fields to edit
    uint256 private maxWalletDivisor = 100;
    uint256 private _maxWalletSize = (_total * maxWalletPercent) / maxWalletDivisor;
    uint256 private _previousMaxWalletSize = _maxWalletSize;
    uint256 public maxWalletSizeUI = (startingSupply * maxWalletPercent) / maxWalletDivisor; // Actual amount for UI's

    bool private sniperProtection = true;
    bool public _hasLiqBeenAdded = false;
    uint256 private _liqAddBlock = 0;
    uint256 private _liqAddStamp = 0;
    uint256 public snipeBlockAmt;
    uint256 public snipersCaught = 0;

    event SniperCaught(address sniperAddress);


    /**
     * @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_, uint256 initialSupply, address owner, uint256 _snipeBlockAmt) {
        _name = name_;
        _symbol = symbol_;
        _liquidityHolders[msg.sender] = true;
        snipeBlockAmt = _snipeBlockAmt;

        IUniswapV2Router02 _dexRouter = IUniswapV2Router02(_routerAddress);
        lpPair = IUniswapV2Factory(_dexRouter.factory())
            .createPair(address(this), _dexRouter.WETH());

        _totalSupply += initialSupply;
        _balances[owner] += initialSupply;
        emit Transfer(address(0), owner, initialSupply);
    }

    /**
     * @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;
    }

    function _hasLimits(address from, address to) private view returns (bool) {
        return !_liquidityHolders[to]
            && !_liquidityHolders[from]
            && to != burnAddress
            && to != address(0);
    }

    function _checkLiquidityAdd(address from, address to) private {
        require(!_hasLiqBeenAdded, "Liquidity already added and marked.");
        if (!_hasLimits(from, to) && to == lpPair) {
            _hasLiqBeenAdded = true;
            _liqAddBlock = block.number;
        }
    }

    /**
     * @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");
        if(_hasLimits(sender, recipient))
            require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount.");
        if(_hasLimits(sender, recipient)
            && recipient != _routerAddress 
            && recipient != lpPair
        ) {
            uint256 contractBalanceRecepient = balanceOf(recipient);
            require(contractBalanceRecepient + amount <= _maxWalletSize, "Transfer amount exceeds the maxWalletSize.");
        }

        _beforeTokenTransfer(sender, recipient);

        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 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));

        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);
    }

    function isBlacklisted(address account) public view returns (bool) {
        return _isBlacklisted[account];
    }

    function setBlacklist(address account, bool enabled) external onlyOwner() {
        require(_isBlacklisted[account] != enabled);
        _isBlacklisted[account] = enabled;
    }

    function setSniperProtectionEnabled(bool enabled) external onlyOwner() {
        require(enabled != sniperProtection, "Already set.");
        sniperProtection = enabled;
    }

    /**
     * @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 sender, address recipient) internal virtual { 
        // Failsafe, disable the whole system if needed.
        if (sniperProtection){
            // If sender is a sniper address, reject the transfer.
            if (isBlacklisted(sender) || isBlacklisted(recipient)) {
                revert("Sniper rejected.");
            }

            // Check if this is the liquidity adding tx to startup.
            if (!_hasLiqBeenAdded) {
                _checkLiquidityAdd(sender, recipient);
                    if (!_hasLiqBeenAdded && _hasLimits(sender, recipient)) {
                        revert("Only owner can transfer at this time.");
                    }
            } else {
                if (_liqAddBlock > 0 
                    && sender == lpPair 
                    && _hasLimits(sender, recipient)
                ) {
                    if (block.number - _liqAddBlock < snipeBlockAmt) {
                        _isBlacklisted[recipient] = true;
                        snipersCaught ++;
                        emit SniperCaught(recipient);
                    }
                }
            }
        }
    }

    function setMaxTxPercent(uint256 percent, uint256 divisor) external onlyOwner() {
        require(divisor <= 10000); // Cannot set lower than 0.01%
        _maxTxAmount = _total.mul(percent).div(
            divisor // Division by divisor, makes it mutable.
        );
        maxTxAmountUI = startingSupply.mul(percent).div(divisor);
    }

    function setMaxWalletSize(uint256 percent, uint256 divisor) external onlyOwner() {
        require(divisor <= 1000); // Cannot set lower than 0.1%
        _maxWalletSize = _total.mul(percent).div(
            divisor // Division by divisor, makes it mutable.
        );
        maxWalletSizeUI = startingSupply.mul(percent).div(divisor);
    }
}
/**
 * @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 guidelines: functions revert instead
 * of 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}.
 */
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 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`.
 */