/**
 *Submitted for verification at Etherscan.io on 2020-11-13
*/

pragma solidity 0.5.17;


library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute
        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
    }
}

interface IERC20 {
    /**
     * @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 `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @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 Optional functions from the ERC20 standard.
 */
contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
     * these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view 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.
     *
     * 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 returns (uint8) {
        return _decimals;
    }
}


library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following 
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @dev Converts an `address` into `address payable`. Note that this is
     * simply a type cast: the actual underlying value is not changed.
     *
     * _Available since v2.4.0._
     */
    function toPayable(address account) internal pure returns (address payable) {
        return address(uint160(account));
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     *
     * _Available since v2.4.0._
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-call-value
        (bool success, ) = recipient.call.value(amount)("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}

library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     *
     * _Available since v2.4.0._
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     *
     * _Available since v2.4.0._
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     *
     * _Available since v2.4.0._
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}


contract ReentrancyGuard {
    bool private _notEntered;

    constructor () internal {
        // Storing an initial non-zero value makes deployment a bit more
        // expensive, but in exchange the refund on every call to nonReentrant
        // will be lower in amount. Since refunds are capped to a percetange of
        // the total transaction's gas, it is best to keep them low in cases
        // like this one, to increase the likelihood of the full refund coming
        // into effect.
        _notEntered = true;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_notEntered, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _notEntered = false;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _notEntered = true;
    }
}

contract Ownable {
    address public owner;
    address public newOwner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor() public {
        owner = msg.sender;
        newOwner = address(0);
    }

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    modifier onlyNewOwner() {
        require(msg.sender != address(0));
        require(msg.sender == newOwner);
        _;
    }
    
    function isOwner(address account) public view returns (bool) {
        if(account == owner) {
            return true;
        }
        else {
            return false;
        }
    }

    function transferOwnership(address _newOwner) public onlyOwner {
        require(_newOwner != address(0));
        newOwner = _newOwner;
    }

    function acceptOwnership() public onlyNewOwner {
        emit OwnershipTransferred(owner, newOwner);        
        owner = newOwner;
        newOwner = address(0);
    }
}

contract Pausable is Ownable {
    event Paused(address account);
    event Unpaused(address account);

    bool private _paused;

    constructor () public {
        _paused = false;
    }    

    modifier whenNotPaused() {
        require(!_paused);
        _;
    }

    modifier whenPaused() {
        require(_paused);
        _;
    }

    function paused() public view returns (bool) {
        return _paused;
    }

    function pause() public onlyOwner whenNotPaused {
        _paused = true;
        emit Paused(msg.sender);
    }

    function unpause() public onlyOwner whenPaused {
        _paused = false;
        emit Unpaused(msg.sender);
    }
}


contract StakingDextoken is ReentrancyGuard, Pausable {
    using SafeERC20 for IERC20;
    using SafeMath for uint;

    event Freeze(address indexed account);
    event Unfreeze(address indexed account);
    event TokenDeposit(address account, uint amount);
    event TokenWithdraw(address account, uint amount);
    event TokenClaim(address account, uint amount);
    event RewardAdded(uint reward);

    uint public periodFinish = 0;
    uint public rewardRate = 0;
    uint public lastUpdateTime;
    uint public rewardPerTokenStored = 0;
    uint public rewardRounds = 0;
    uint public rewardsDuration = 0;
    bool public inStaking = true;

    // BAL beneficial address
    address public beneficial = address(this);

    // User award balance
    mapping(address => uint) public rewards;
    mapping(address => uint) public userRewardPerTokenPaid;

    uint private _start;
    uint private _end;

    /// Staking token
    IERC20 private _token0;

    /// Reward token
    IERC20 private _token1;

    /// Total rewards
    uint private _rewards;
    uint private _remainingRewards;

    /// Total amount of user staking tokens
    uint private _totalSupply;

    mapping(address => bool) public frozenAccount;

    /// The staking users
    mapping(address => bool) public stakeHolders;

    /// The amount of tokens staked
    mapping(address => uint) private _balances;

    /// The remaining withdrawals of staked tokens
    mapping(address => uint) internal withdrawalOf;  

    /// The remaining withdrawals of reward tokens
    mapping(address => uint) internal claimOf;

    constructor (address token0, address token1) public {
        require(token0 != address(0), "DEXToken: zero address");
        require(token1 != address(0), "DEXToken: zero address");

        _token0 = IERC20(token0);
        _token1 = IERC20(token1);
    }

    modifier notFrozen(address _account) {
        require(!frozenAccount[_account]);
        _;
    }

    modifier updateReward(address account) {
        rewardPerTokenStored = rewardPerToken();
        lastUpdateTime = lastTimeRewardApplicable();
        if (account != address(0)) {
            rewards[account] = earned(account);
            userRewardPerTokenPaid[account] = rewardPerTokenStored;
        }
        _;
    }

    function setBeneficial(address _beneficial) onlyOwner external {
        require(_beneficial != address(this), "setBeneficial: can not send to self");
        require(_beneficial != address(0), "setBeneficial: can not burn tokens");
        beneficial = _beneficial;
    }

    /// Capture BAL tokens or any other tokens
    function capture(address _token, uint amount) onlyOwner external {
        require(_token != address(_token0), "capture: can not capture staking tokens");
        require(_token != address(_token1), "capture: can not capture reward tokens");
        require(beneficial != address(this), "capture: can not send to self");
        require(beneficial != address(0), "capture: can not burn tokens");
        IERC20(_token).safeTransfer(beneficial, amount);
    }  

    function lastTimeRewardApplicable() public view returns (uint) {
        return Math.min(block.timestamp, periodFinish);
    }

    function rewardPerToken() public view returns (uint) {
        if (getTotalStakes() == 0) {
            return rewardPerTokenStored;
        }
        return
            rewardPerTokenStored.add(
                lastTimeRewardApplicable()
                    .sub(lastUpdateTime)
                    .mul(rewardRate)
                    .mul(1e18)
                    .div(getTotalStakes())
            );
    }

    function earned(address account) public view returns (uint) {
        return
            balanceOf(account)
                .mul(rewardPerToken().sub(userRewardPerTokenPaid[account]))
                .div(1e18)
                .add(rewards[account]);
    }

    /// setup the staking round
    function setRewardRound(uint round, uint reward, uint start, uint end) 
        external
        onlyOwner    
    {
        require(block.timestamp > periodFinish, "setRewardRound: previous rewards period not complete");
        require(rewardRounds < round, "setRewardRound: this round completed");

        rewardRounds = round;
        _rewards = reward;
        _start = start;
        _end = end;
        rewardsDuration = _end.sub(_start);

        inStaking = false;
    }

    /// launch the staking round
    function notifyRewards()
        external
        onlyOwner
        updateReward(address(0))
    {
        // staking started
        if (inStaking == true) {
            return;
        }

        if (block.timestamp >= periodFinish) {
            rewardRate = _rewards.div(rewardsDuration);
        } else {
            uint remaining = periodFinish.sub(block.timestamp);
            uint leftover = remaining.mul(rewardRate);
            rewardRate = _rewards.add(leftover).div(rewardsDuration);
            _remainingRewards = leftover;
        }

        // Ensure the provided reward amount is not more than the balance in the contract.
        // This keeps the reward rate in the right range, preventing overflows due to
        // very high values of rewardRate in the earned and rewardsPerToken functions;
        // Reward + leftover must be less than 2^256 / 10^18 to avoid overflow.
        uint balance = _token1.balanceOf(address(this));
        require(rewardRate <= balance.div(rewardsDuration), "notifyRewards: provided reward too high");

        inStaking = true;
        lastUpdateTime = block.timestamp;
        periodFinish = block.timestamp.add(rewardsDuration);
        emit RewardAdded(_rewards);
    }

    function addStakeholder(address _stakeholder) internal {
        stakeHolders[_stakeholder] = true;
    }

    function removeStakeholder(address _stakeholder) internal {
        stakeHolders[_stakeholder] = false;
    }

    /// Deposit staking tokens
    function deposit(uint amount) 
        external 
        nonReentrant
        whenNotPaused 
        notFrozen(msg.sender) 
        updateReward(msg.sender)
    {
        require(amount > 0, "deposit: cannot stake 0");
        require(msg.sender != address(0), "withdraw: zero address");
        require(_token0.balanceOf(msg.sender) >= amount, "deposit: insufficient balance");
        _totalSupply = _totalSupply.add(amount);          
        _balances[msg.sender] = _balances[msg.sender].add(amount);
        addStakeholder(msg.sender);
        _token0.safeTransferFrom(msg.sender, address(this), amount);
        emit TokenDeposit(msg.sender, amount);
    }

    /// Withdraw staked tokens
    function withdraw(uint amount) 
        external 
        nonReentrant
        whenNotPaused 
        notFrozen(msg.sender) 
        updateReward(msg.sender)
    {
        require(amount > 0, "withdraw: amount invalid");
        require(msg.sender != address(0), "withdraw: zero address");
        /// Not overflow
        require(_balances[msg.sender] >= amount);
        _totalSupply = _totalSupply.sub(amount);                
        _balances[msg.sender] = _balances[msg.sender].sub(amount);
        /// Keep track user withdraws
        withdrawalOf[msg.sender] = withdrawalOf[msg.sender].add(amount);  
        if (_balances[msg.sender] == 0) {
            removeStakeholder(msg.sender);   
        }
        _token0.safeTransfer(msg.sender, amount);
        emit TokenWithdraw(msg.sender, amount);
    }

    /// Claim reward tokens
    function claim() 
        external 
        nonReentrant
        whenNotPaused 
        notFrozen(msg.sender) 
        updateReward(msg.sender)
    {
        require(msg.sender != address(0), "claim: zero address");        
        require(block.timestamp > getEndTimestamp(), "claim: claim not open");   
        require(block.timestamp > periodFinish, "claim: current staking period not complete");

        uint reward = earned(msg.sender);
        /// Not overflow        
        require(_token1.balanceOf(address(this)) >= reward, "claim: insufficient balance");        
        require(reward > 0, "claim: zero rewards");                

        rewards[msg.sender] = 0;
        claimOf[msg.sender] = reward;
        _token1.safeTransfer(msg.sender, reward);
        emit TokenClaim(msg.sender, reward);
    }

    function freezeAccount(address account) external onlyOwner returns (bool) {
        require(!frozenAccount[account], "ERC20: account frozen");
        frozenAccount[account] = true;
        emit Freeze(account);
        return true;
    }

    function unfreezeAccount(address account) external onlyOwner returns (bool) {
        require(frozenAccount[account], "ERC20: account not frozen");
        frozenAccount[account] = false;
        emit Unfreeze(account);
        return true;
    }

    function getWithdrawalOf(address _stakeholder) external view returns (uint) {
        return withdrawalOf[_stakeholder];
    }

    function getClaimOf(address _stakeholder) external view returns (uint) {
        return claimOf[_stakeholder];
    }

    /// Get remaining rewards of the time period
    function remainingRewards() external view returns(uint) {
        return _remainingRewards;
    }

    /// Retrieve the stake for a stakeholder
    function stakeOf(address _stakeholder) external view returns (uint) {
        return _balances[_stakeholder];
    }

    /// Retrieve the stake for a stakeholder
    function rewardOf(address _stakeholder) external view returns (uint) {
        return earned(_stakeholder);
    }

    /// Get total original rewards
    function totalRewards() external view returns (uint) {
        return _rewards;
    }  

    function getStartTimestamp() public view returns (uint) {
        return _start;
    }

    function getEndTimestamp() public view returns (uint) {
        return _end;
    }

    /// The total supply of all staked tokens
    function getTotalStakes() public view returns (uint) {
        return _totalSupply;
    }

    function balanceOf(address account) public view returns (uint) {
        return _balances[account];
    }    
}

{
  "compilationTarget": {
    "StakingDextoken.sol": "StakingDextoken"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}