Working on

Giveaway Contract

BNBRewardNiubi contract (stake NIU get BNB)

Address: 0x...

Similar functionality as Pancakeswap’s Smartchef contract (0x92E8CeB7eAeD69fB6E4d9dA43F605D2610214E68). Stake NIU (Niubi Token) tokens, and get reward in native BNB (not WBNB). Hence few changes and additions are made.

depositBNBRewards is an external payable function. Anyone can send BNB to the contract and increase the contract’s BNB balance.

rewardBalance is a public view function which returns the BNB balance of the contract.

safeTransferBNB is an internal function used to transfer native BNB to an address. The external call to transfer is done with a gas limit of 23000.

The contract owner is able to withdraw an arbitrary amount of BNB, up to a maximum of the contract’s balance, from the contract using emergencyRewardWithdraw.

contracts/BNBRewardNiubi.sol
/**
 *Submitted for verification at BscScan.com on 2021-03-XX
*/

// File: @pancakeswap/pancake-swap-lib/contracts/math/SafeMath.sol

// SPDX-License-Identifier: MIT

pragma solidity >=0.4.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
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.
     */
    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.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        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.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }

    function min(uint256 x, uint256 y) internal pure returns (uint256 z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint256 y) internal pure returns (uint256 z) {
        if (y > 3) {
            z = y;
            uint256 x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: @pancakeswap/pancake-swap-lib/contracts/token/BEP20/IBEP20.sol

// License-Identifier: GPL-3.0-or-later

pragma solidity >=0.4.0;

interface IBEP20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the token decimals.
     */
    function decimals() external view returns (uint8);

    /**
     * @dev Returns the token symbol.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the token name.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the bep token owner.
     */
    function getOwner() external view returns (address);

    /**
     * @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);
}

// File: @pancakeswap/pancake-swap-lib/contracts/utils/Address.sol

// License-Identifier: MIT

pragma solidity ^0.6.2;

/**
 * @dev Collection of functions related to the address type
 */
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 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].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, 'Address: insufficient balance');

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

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, 'Address: low-level call failed');
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, 'Address: low-level call with value failed');
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, 'Address: insufficient balance for call');
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 weiValue,
        string memory errorMessage
    ) private returns (bytes memory) {
        require(isContract(target), 'Address: call to non-contract');

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{value: weiValue}(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @pancakeswap/pancake-swap-lib/contracts/token/BEP20/SafeBEP20.sol

// License-Identifier: MIT

pragma solidity ^0.6.0;




/**
 * @title SafeBEP20
 * @dev Wrappers around BEP20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeBEP20 for IBEP20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeBEP20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(
        IBEP20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IBEP20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IBEP20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IBEP20 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),
            'SafeBEP20: approve from non-zero to non-zero allowance'
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IBEP20 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(
        IBEP20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(
            value,
            'SafeBEP20: 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(IBEP20 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. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, 'SafeBEP20: low-level call failed');
        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), 'SafeBEP20: BEP20 operation did not succeed');
        }
    }
}

// File: @pancakeswap/pancake-swap-lib/contracts/GSN/Context.sol

// License-Identifier: GPL-3.0-or-later

pragma solidity >=0.4.0;

/*
 * @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 GSN 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.
 */
contract Context {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.
    constructor() internal {}

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @pancakeswap/pancake-swap-lib/contracts/access/Ownable.sol

// License-Identifier: GPL-3.0-or-later

pragma solidity >=0.4.0;


/**
 * @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.
 */
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() internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        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 onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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 onlyOwner {
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     */
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0), 'Ownable: new owner is the zero address');
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: contracts/BNBRewardNiubi.sol

pragma solidity 0.6.12;

/*
 * Niubiswap
 * App:             https://www.niubiswap.com 
 * Twitter:         https://twitter.com/officialniubi 
 * Telegram:        https://t.me/niubiswap
 */






contract BNBRewardNiubi is Ownable {
    using SafeMath for uint256;
    using SafeBEP20 for IBEP20;

    // Info of each user.
    struct UserInfo {
        uint256 amount;     // How many LP tokens the user has provided.
        uint256 rewardDebt; // Reward debt. See explanation below.
    }

    // Info of each pool.
    struct PoolInfo {
        IBEP20 lpToken;           // Address of LP token contract.
        uint256 allocPoint;       // How many allocation points assigned to this pool. Rewards to distribute per block.
        uint256 lastRewardBlock;  // Last block number that Rewards distribution occurs.
        uint256 accRewardTokenPerShare; // Accumulated Rewards per share, times 1e12. See below.
    }

    // The stake TOKEN!
    IBEP20 public stakeToken;

    // Reward tokens created per block.
    uint256 public rewardPerBlock;


    // Info of each pool.
    PoolInfo[] public poolInfo;
    // Info of each user that stakes LP tokens.
    mapping (address => UserInfo) public userInfo;
    // Total allocation poitns. Must be the sum of all allocation points in all pools.
    uint256 private totalAllocPoint = 0;
    // The block number when Reward mining starts.
    uint256 public startBlock;
	// The block number when mining ends.	
    uint256 public bonusEndBlock;

    event Deposit(address indexed user, uint256 amount);
    event DepositBNBRewards(uint256 amount);
    event Withdraw(address indexed user, uint256 amount);
    event EmergencyWithdraw(address indexed user, uint256 amount);
    event EmergencyRewardWithdraw(address indexed user, uint256 amount);

    constructor(
        IBEP20 _stakeToken,
        uint256 _rewardPerBlock,
        uint256 _startBlock,
        uint256 _bonusEndBlock
    ) public {
        stakeToken = _stakeToken;
        rewardPerBlock = _rewardPerBlock;
        startBlock = _startBlock;
        bonusEndBlock = _bonusEndBlock;

        // staking pool
        poolInfo.push(PoolInfo({
            lpToken: _stakeToken,
            allocPoint: 1000,
            lastRewardBlock: startBlock,
            accRewardTokenPerShare: 0
        }));

        totalAllocPoint = 1000;

    }

    // Return reward multiplier over the given _from to _to block.
    function getMultiplier(uint256 _from, uint256 _to) public view returns (uint256) {
        if (_to <= bonusEndBlock) {
            return _to.sub(_from);
        } else if (_from >= bonusEndBlock) {
            return 0;
        } else {
            return bonusEndBlock.sub(_from);
        }
    }

    // View function to see pending Reward on frontend.
    function pendingReward(address _user) external view returns (uint256) {
        PoolInfo storage pool = poolInfo[0];
        UserInfo storage user = userInfo[_user];
        uint256 accRewardTokenPerShare = pool.accRewardTokenPerShare;
        uint256 lpSupply = pool.lpToken.balanceOf(address(this));
        if (block.number > pool.lastRewardBlock && lpSupply != 0) {
            uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
            uint256 tokenReward = multiplier.mul(rewardPerBlock).mul(pool.allocPoint).div(totalAllocPoint);
            accRewardTokenPerShare = accRewardTokenPerShare.add(tokenReward.mul(1e12).div(lpSupply));
        }
        return user.amount.mul(accRewardTokenPerShare).div(1e12).sub(user.rewardDebt);
    }

    // Update reward variables of the given pool to be up-to-date.
    function updatePool(uint256 _pid) public {
        PoolInfo storage pool = poolInfo[_pid];
        if (block.number <= pool.lastRewardBlock) {
            return;
        }
        uint256 lpSupply = pool.lpToken.balanceOf(address(this));
        if (lpSupply == 0) {
            pool.lastRewardBlock = block.number;
            return;
        }
        uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
        uint256 tokenReward = multiplier.mul(rewardPerBlock).mul(pool.allocPoint).div(totalAllocPoint);
        pool.accRewardTokenPerShare = pool.accRewardTokenPerShare.add(tokenReward.mul(1e12).div(lpSupply));
        pool.lastRewardBlock = block.number;
    }

    // Update reward variables for all pools. Be careful of gas spending!
    function massUpdatePools() public {
        uint256 length = poolInfo.length;
        for (uint256 pid = 0; pid < length; ++pid) {
            updatePool(pid);
        }
    }


    /// Deposit staking token into the contract to earn rewards. 
    /// @dev Since this contract needs to be supplied with rewards we are 
    ///  sending the balance of the contract if the pending rewards are higher
    /// @param _amount The amount of staking tokens to deposit
    function deposit(uint256 _amount) public {
        PoolInfo storage pool = poolInfo[0];
        UserInfo storage user = userInfo[msg.sender];
        updatePool(0);
        if (user.amount > 0) {
            uint256 pending = user.amount.mul(pool.accRewardTokenPerShare).div(1e12).sub(user.rewardDebt);
            if(pending > 0) {
                uint256 currentRewardBalance = rewardBalance();
                if(currentRewardBalance > 0) {
                    if(pending > currentRewardBalance) {
                        safeTransferBNB(address(msg.sender), currentRewardBalance);
                    } else {
                        safeTransferBNB(address(msg.sender), pending);
                    }
                }
            }
        }
        if(_amount > 0) {
            pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);
            user.amount = user.amount.add(_amount);
        }
        user.rewardDebt = user.amount.mul(pool.accRewardTokenPerShare).div(1e12);

        emit Deposit(msg.sender, _amount);
    }

    /// Withdraw rewards and/or staked tokens. Pass a 0 amount to withdraw only rewards 
    /// @param _amount The amount of staking tokens to withdraw
    function withdraw(uint256 _amount) public {
        PoolInfo storage pool = poolInfo[0];
        UserInfo storage user = userInfo[msg.sender];
        require(user.amount >= _amount, "withdraw: not good");
        updatePool(0);
        uint256 pending = user.amount.mul(pool.accRewardTokenPerShare).div(1e12).sub(user.rewardDebt);
        if(pending > 0) {
            uint256 currentRewardBalance = rewardBalance();
            if(currentRewardBalance > 0) {
                if(pending > currentRewardBalance) {
                    safeTransferBNB(address(msg.sender), currentRewardBalance);
                } else {
                    safeTransferBNB(address(msg.sender), pending);
                }
            }
        }
        if(_amount > 0) {
            user.amount = user.amount.sub(_amount);
            pool.lpToken.safeTransfer(address(msg.sender), _amount);
        }

        user.rewardDebt = user.amount.mul(pool.accRewardTokenPerShare).div(1e12);

        emit Withdraw(msg.sender, _amount);
    }

    /// Obtain the reward balance of this contract
    /// @return wei balance of contract
    function rewardBalance() public view returns (uint256) {
        return payable(address(this)).balance;
    }

    // Deposit Rewards into contract
    function depositBNBRewards() external payable {
        require(msg.value > 0, 'Message has no BNB value to deposit into contract.');
        emit DepositBNBRewards(msg.value);
    }

    /// @param to address to send BNB to
    /// @param value wei value of BNB to transfer
    function safeTransferBNB(address to, uint256 value) internal {
        // Transfer BNB to address
        (bool success, ) = to.call{gas: 23000, value: value}("");
        require(success, 'TransferHelper: BNB_TRANSFER_FAILED');
    }

    /* Emergency Functions */ 

    // Withdraw without caring about rewards. EMERGENCY ONLY.
    function emergencyWithdraw() external {
        PoolInfo storage pool = poolInfo[0];
        UserInfo storage user = userInfo[msg.sender];
        pool.lpToken.safeTransfer(address(msg.sender), user.amount);
        user.amount = 0;
        user.rewardDebt = 0;
        emit EmergencyWithdraw(msg.sender, user.amount);
    }

    // Withdraw reward. EMERGENCY ONLY.
    function emergencyRewardWithdraw(uint256 _amount) external onlyOwner {
        require(_amount <= rewardBalance(), 'not enough rewards');
        // Withdraw the BNB rewards
        safeTransferBNB(address(msg.sender), _amount);
        emit EmergencyRewardWithdraw(msg.sender, _amount);
    }

}

Contract ABI

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Project status:

Pending verification by Solidity dev (Light audit) (avg 3-7days)

Call for help:

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Last updated