// File: @openzeppelin/contracts/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @openzeppelin/contracts/utils/Context.sol


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: contracts/TAXHAVENINU_Staking.sol


pragma solidity ^0.8.7;



contract TAXHAVENINU_STAKING is Ownable {
    IERC20 public TOKEN;
    
    struct Share {
        uint256 amount;
        uint256 excluded;
        uint256 rewardConfirmed;
        uint256 rewardClaimed;
    }

    address[] public shareholders;
    mapping(address => uint256) public shareholderIndexes;
    
    mapping(address => Share) public shares;

    uint256 public totalShares;
    uint256 public totalDividends;
    uint256 public totalDistributed;
    uint256 public dividendsPerShare;
    uint256 public dividendsPerShareAccuracyFactor;
    
    constructor() {
        dividendsPerShareAccuracyFactor = 10**36;
    }

    function getTotalStakersAmount() public view returns (uint256) {
        return shareholders.length;
    }

    function stake(uint256 tokenAmount) external {
        if (shares[msg.sender].amount > 0) {
            distributeDividend(msg.sender);
        }

        if (tokenAmount > 0) {
            if (shares[msg.sender].amount == 0) addShareholder(msg.sender);
            TOKEN.transferFrom(msg.sender, address(this), tokenAmount);
            totalShares = totalShares + tokenAmount;
        }

        shares[msg.sender].amount = shares[msg.sender].amount + tokenAmount;
        shares[msg.sender].excluded = getCumulativeDividends(shares[msg.sender].amount);
    }

    function unstake(uint256 tokenAmount) external {
        if (shares[msg.sender].amount > 0) {
            distributeDividend(msg.sender);
        }

        if (shares[msg.sender].amount <= tokenAmount) {
            removeShareholder(msg.sender);
            TOKEN.transfer(msg.sender, shares[msg.sender].amount);
            totalShares = totalShares - shares[msg.sender].amount;
            shares[msg.sender].amount = 0;
        } else {
            TOKEN.transfer(msg.sender, tokenAmount);
            totalShares = totalShares - tokenAmount;
            shares[msg.sender].amount = shares[msg.sender].amount - tokenAmount;
        }

        shares[msg.sender].excluded = getCumulativeDividends(shares[msg.sender].amount);
    }

    function getCumulativeDividends(uint256 share) internal view returns (uint256) {
        return share * dividendsPerShare / 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();
    }

    function distributeDividend(address shareholder) internal {
        if (shares[shareholder].amount == 0) return;

        uint256 amount = getUnpaidEarnings(shareholder);
        if (amount > 0) {
            totalDistributed = totalDistributed + amount;
            shares[shareholder].rewardConfirmed = shares[shareholder].rewardConfirmed + amount;
            shares[shareholder].excluded = getCumulativeDividends(shares[shareholder].amount);
        }
    }

    function getUnpaidEarnings(address shareholder) internal view returns (uint256) {
        if (shares[shareholder].amount == 0) return 0;

        uint256 shareholderTotalDividends = getCumulativeDividends(shares[shareholder].amount);

        uint256 shareholderTotalExcluded = shares[shareholder].excluded;

        if (shareholderTotalDividends <= shareholderTotalExcluded) return 0;

        return shareholderTotalDividends - shareholderTotalExcluded;
    }

    function getUnclaimedRewards(address shareholder) public view returns (uint256) {
        return shares[shareholder].rewardConfirmed + getUnpaidEarnings(shareholder);
    }

    function getClaimedRewards(address shareholder) public view returns (uint256) {
        return shares[shareholder].rewardClaimed;
    }

    receive() external payable {
        totalDividends = totalDividends + msg.value;
        dividendsPerShare = totalDividends / totalShares;
    }

    function claimRewards() external {
        distributeDividend(msg.sender);
        require(shares[msg.sender].rewardConfirmed > 0, "Nothing Rewards");

        payable(msg.sender).transfer(shares[msg.sender].rewardConfirmed);
        shares[msg.sender].rewardClaimed = shares[msg.sender].rewardClaimed + shares[msg.sender].rewardConfirmed;
        shares[msg.sender].rewardConfirmed = 0;
    }

    function withdrawETH(address _addr) external onlyOwner {
        uint256 balance = address(this).balance;
        payable(_addr).transfer(balance);
        totalDividends = totalDividends - balance;
        dividendsPerShare = totalDividends / totalShares;
    }
}