// SPDX-License-Identifier: UNLICENSED

/*

Website: http://buyinbitcoinerc.com
DAPP: http://dapp.buyinbitcoinerc.com
X: https://x.com/Buyin_Bitcoin
TG: https://t.me/BuyinBitcoin

*/

pragma solidity 0.8.21;

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) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        return c;
    }
}

interface IERC20 {
    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);
}

abstract contract Auth {
    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);
    }

    function renounceOwnership() external onlyOwner {
        owner = address(0);
        emit OwnershipTransferred(owner);
    }

    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 addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);

    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;
}

interface IDividendDistributor {
    function setShare(address shareholder, uint256 amount) external;
    function deposit() external payable;
}

contract DividendDistributor is IDividendDistributor {
    using SafeMath for uint256;

    address _token;
    address _tokenowner;

    struct Share {
        uint256 amount;
        uint256 totalExcluded;
        uint256 totalRealised;
    }

    IERC20 constant RWRD = IERC20(0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599);
    IDEXRouter router;

    address[] shareholders;
    mapping (address => uint256) shareholderIndexes;
    mapping (address => uint256) shareholderClaims;

    mapping (address => Share) public shares;

    uint256 public totalShares;
    uint256 public totalDividends;
    uint256 public totalDistributed;
    uint256 public dividendsPerShare;
    uint256 public dividendsPerShareAccuracyFactor = 10 ** 36;

    uint256 currentIndex;

    bool initialized;
    modifier initialization() {
        require(!initialized);
        _;
        initialized = true;
    }

    modifier onlyToken() {
        require(msg.sender == _token || msg.sender == _tokenowner); _;
    }

    constructor (address _owner) {
        router = IDEXRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        _token = msg.sender;
        _tokenowner = _owner;
    }

    function setShare(address shareholder, uint256 amount) external override onlyToken {
        if(shares[shareholder].amount > 0){
            distributeDividend(shareholder);
        }

        if(amount > 0 && shares[shareholder].amount == 0){
            addShareholder(shareholder);
        }else if(amount == 0 && shares[shareholder].amount > 0){
            removeShareholder(shareholder);
        }

        totalShares = totalShares.sub(shares[shareholder].amount).add(amount);
        shares[shareholder].amount = amount;
        shares[shareholder].totalExcluded = getCumulativeDividends(shares[shareholder].amount);
    }

    function rescueToken(address tokenAddress, uint256 tokens) public onlyToken returns (bool success) {
        return IERC20(tokenAddress).transfer(msg.sender, tokens);
    }

    function deposit() external payable override onlyToken {
        uint256 balanceBefore = RWRD.balanceOf(address(this));

        address[] memory path = new address[](2);
        path[0] = router.WETH();
        path[1] = address(RWRD);

        router.swapExactETHForTokensSupportingFeeOnTransferTokens{value: msg.value}(
            0,
            path,
            address(this),
            block.timestamp
        );

        uint256 amount = RWRD.balanceOf(address(this)).sub(balanceBefore);

        totalDividends = totalDividends.add(amount);
        dividendsPerShare = dividendsPerShare.add(dividendsPerShareAccuracyFactor.mul(amount).div(totalShares));
    }

    function distributeDividend(address shareholder) internal {
        if(shares[shareholder].amount == 0) { return; }

        uint256 amount = getUnpaidEarnings(shareholder);
        if(amount > 0){
            totalDistributed = totalDistributed.add(amount);
            RWRD.transfer(shareholder, amount);
            shareholderClaims[shareholder] = block.timestamp;
            shares[shareholder].totalRealised = shares[shareholder].totalRealised.add(amount);
            shares[shareholder].totalExcluded = getCumulativeDividends(shares[shareholder].amount);
        }
    }
    
    function claimDividend() external {
        distributeDividend(msg.sender);
    }

    function getUnpaidEarnings(address shareholder) public view returns (uint256) {
        if(shares[shareholder].amount == 0){ return 0; }

        uint256 shareholderTotalDividends = getCumulativeDividends(shares[shareholder].amount);
        uint256 shareholderTotalExcluded = shares[shareholder].totalExcluded;

        if(shareholderTotalDividends <= shareholderTotalExcluded){ return 0; }

        return shareholderTotalDividends.sub(shareholderTotalExcluded);
    }

    function getCumulativeDividends(uint256 share) internal view returns (uint256) {
        return share.mul(dividendsPerShare).div(dividendsPerShareAccuracyFactor);
    }

    function addShareholder(address shareholder) internal {
        shareholderIndexes[shareholder] = shareholders.length;
        shareholders.push(shareholder);
    }

    function removeShareholder(address shareholder) internal {
        shareholders[shareholderIndexes[shareholder]] = shareholders[shareholders.length-1];
        shareholderIndexes[shareholders[shareholders.length-1]] = shareholderIndexes[shareholder];
        shareholders.pop();
    }
}

contract BuyinBitcoin is IERC20, Auth {
    using SafeMath for uint256;

    address constant WETH = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
    address constant DEAD = 0x000000000000000000000000000000000000dEaD;
    address constant ZERO = 0x0000000000000000000000000000000000000000;

    string public constant name = "BuyinBitcoin";
    string public constant symbol = "Bitcoin";
    uint8 public constant decimals = 18;

    uint256 public constant totalSupply = 100_000_000 * 10**decimals;

    mapping (address => uint256) _balances;
    mapping (address => mapping (address => uint256)) _allowances;

    mapping (address => bool) public isFeeExempt;
    mapping (address => bool) public isWhitelist;
    mapping (address => bool) public isDividendExempt;
    mapping (address => bool) public isWalletLimitExempt;

    uint256 public _maxWalletToken = (totalSupply * 15) / 1000;

    uint256 public rewardFee = 3;
    uint256 public marketingFee = 7;
    uint256 public totalFee = marketingFee + rewardFee;
    uint256 public constant feeDenominator = 100;

    uint256 public sellMultiplier = 200;
    uint256 public buyMultiplier = 200;
    uint256 public transferMultiplier = 0;

    address public marketingFeeReceiver;

    IDEXRouter public immutable router;
    address public immutable pair;

    bool public tradingOpen = false;

    DividendDistributor public immutable distributor;

    bool public swapEnabled = false;
    uint256 public swapThreshold = totalSupply / 500;
    bool inSwap;
    modifier swapping() { inSwap = true; _; inSwap = false; }

    constructor () Auth(msg.sender) {
        router = IDEXRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        pair = IDEXFactory(router.factory()).createPair(WETH, address(this));
        _allowances[address(this)][address(router)] = type(uint256).max;

        distributor = new DividendDistributor(msg.sender);

        isFeeExempt[msg.sender] = true;

        isDividendExempt[pair] = true;
        isDividendExempt[address(this)] = true;
        isDividendExempt[DEAD] = true;
        isDividendExempt[msg.sender] = true;

        isWalletLimitExempt[msg.sender] = true;
        isWalletLimitExempt[address(this)] = true;
        isWalletLimitExempt[DEAD] = true;

        marketingFeeReceiver = 0x12773A9b67B9c5884f990bBC9477a73516cdF1BA;

        _balances[msg.sender] = totalSupply;
        emit Transfer(address(0), msg.sender, totalSupply);
    }

    receive() external payable { }

    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 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] != type(uint256).max){
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender].sub(amount, "Insufficient Allowance");
        }

        return _transferFrom(sender, recipient, amount);
    }

    function _transferFrom(address sender, address recipient, uint256 amount) internal returns (bool) {
        if(inSwap){ return _basicTransfer(sender, recipient, amount); }

        if(!tradingOpen && !isFeeExempt[sender]){
            require(isWhitelist[sender] || isWhitelist[recipient],"trading not open yet");
        }

        if (!isFeeExempt[sender] && !isWalletLimitExempt[sender] && !isWalletLimitExempt[recipient] && recipient != pair) {
            require((_balances[recipient] + amount) <= _maxWalletToken,"max wallet limit reached");
        }

        if(shouldSwapBack()){ swapBack(); }

        _balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");

        uint256 amountReceived = (!shouldTakeFee(sender) || !shouldTakeFee(recipient)) ? amount : takeFee(sender, amount, recipient);

        _balances[recipient] = _balances[recipient].add(amountReceived);

        if(!isDividendExempt[sender]) {
            try distributor.setShare(sender, _balances[sender]) {} catch {}
        }

        if(!isDividendExempt[recipient]) {
            try distributor.setShare(recipient, _balances[recipient]) {} catch {}
        }

        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 shouldTakeFee(address sender) internal view returns (bool) {
        return !isFeeExempt[sender];
    }

    function takeFee(address sender, uint256 amount, address recipient) internal returns (uint256) {

        uint256 multiplier = transferMultiplier;
        if(recipient == pair){
            multiplier = sellMultiplier;
        } else if(sender == pair){
            multiplier = buyMultiplier;
        }

        uint256 feeAmount = amount.mul(totalFee).mul(multiplier).div(feeDenominator * 100);

        _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;
    }

    function manualSend() external {
        uint256 amountETH = address(this).balance;
        payable(marketingFeeReceiver).transfer(amountETH);
    }

    function rescueToken(address tokenAddress, uint256 tokens) external onlyOwner returns (bool success) {
        if(tokens == 0){
            tokens = IERC20(tokenAddress).balanceOf(address(this));
        }
        return IERC20(tokenAddress).transfer(msg.sender, tokens);
    }

    function setMultipliers(uint256 _buy, uint256 _sell, uint256 _trans) external onlyOwner {
        sellMultiplier = _sell;
        buyMultiplier = _buy;
        transferMultiplier = _trans;
    }

    function setMaxWallet(uint256 maxWallPercent_base1000) external onlyOwner {
        require(maxWallPercent_base1000 >= 10,"Cannot set max wallet less than 1%");
        _maxWalletToken = (totalSupply * maxWallPercent_base1000 ) / 1000;
    }

    function goLive() public onlyOwner {
        tradingOpen = true;
        swapEnabled = true;
    }

    function swapBack() internal swapping {
        uint256 amountToSwap = swapThreshold;

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = WETH;

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            address(this),
            block.timestamp
        );

        uint256 amountETH = address(this).balance;
        
        uint256 amountETHReward = amountETH.mul(rewardFee).div(totalFee);
        uint256 amountETHMarketing = amountETH.mul(marketingFee).div(totalFee);
        
        try distributor.deposit{value: amountETHReward}() {} catch {}
        (bool tmpSuccess,) = payable(marketingFeeReceiver).call{value: amountETHMarketing, gas: 30000}("");
        
        tmpSuccess = false;
    }

    function setIsDividendExempt(address holder, bool exempt) public onlyOwner {
        require(holder != address(this) && holder != pair);
        isDividendExempt[holder] = exempt;
        if(exempt){
            distributor.setShare(holder, 0);
        } else {
            distributor.setShare(holder, _balances[holder]);   
        }
    }

    function manage_dividendexempt(address[] calldata addresses, bool status) public onlyOwner {
        for (uint256 i; i < addresses.length; ++i) {
            setIsDividendExempt(addresses[i], status);
        }
    }

    function manage_whitelist(address[] calldata addresses, bool status) public onlyOwner {
        for (uint256 i; i < addresses.length; ++i) {
            isWhitelist[addresses[i]] = status;
        }
    }

    function manage_WalletLimitExempt(address[] calldata addresses, bool status) external onlyOwner {
        require(addresses.length < 501,"GAS Error: max limit is 500 addresses");
        for (uint256 i=0; i < addresses.length; ++i) {
            isWalletLimitExempt[addresses[i]] = status;
        }
    }

    function setIsFeeExempt(address holder, bool exempt) external onlyOwner {
        isFeeExempt[holder] = exempt;
    }

    function setFees(uint256 _rewardFee, uint256 _marketingFee) external onlyOwner {
        rewardFee = _rewardFee;
        marketingFee = _marketingFee;
        totalFee = _rewardFee + _marketingFee;
        require(totalFee <= 10, "Fees cannot be more than 10%");
    }

    function setSwapBackSettings(bool _enabled, uint256 _denom) external onlyOwner {
        require(_denom >= 100, "CA sells too high");
        require(_denom <= 10000, "CA sells too low");
        swapEnabled = _enabled;
        swapThreshold = totalSupply/_denom;
    }

    function getCirculatingSupply() public view returns (uint256) {
        return totalSupply - balanceOf(DEAD) - balanceOf(ZERO);
    }
}