pragma solidity 0.6.6;


/**
 * @title Initializable
 *
 * @dev Helper contract to support initializer functions. To use it, replace
 * the constructor with a function that has the `initializer` modifier.
 * WARNING: Unlike constructors, initializer functions must be manually
 * invoked. This applies both to deploying an Initializable contract, as well
 * as extending an Initializable contract via inheritance.
 * WARNING: When used with inheritance, manual care must be taken to not invoke
 * a parent initializer twice, or ensure that all initializers are idempotent,
 * because this is not dealt with automatically as with constructors.
 */
contract Initializable {

  /**
   * @dev Indicates that the contract has been initialized.
   */
  bool private initialized;

  /**
   * @dev Indicates that the contract is in the process of being initialized.
   */
  bool private initializing;

  /**
   * @dev Modifier to use in the initializer function of a contract.
   */
  modifier initializer() {
    require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");

    bool isTopLevelCall = !initializing;
    if (isTopLevelCall) {
      initializing = true;
      initialized = true;
    }

    _;

    if (isTopLevelCall) {
      initializing = false;
    }
  }

  /// @dev Returns true if and only if the function is running in the constructor
  function isConstructor() private view returns (bool) {
    // extcodesize checks the size of the code stored in an address, and
    // address returns the current address. Since the code is still not
    // deployed when running a constructor, any checks on its code size will
    // yield zero, making it an effective way to detect if a contract is
    // under construction or not.
    address self = address(this);
    uint256 cs;
    assembly { cs := extcodesize(self) }
    return cs == 0;
  }

  // Reserved storage space to allow for layout changes in the future.
  uint256[50] private ______gap;
}

/*
 * @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 ContextUpgradeSafe is Initializable {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.

    function __Context_init() internal initializer {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal initializer {


    }


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

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

    uint256[50] private __gap;
}

/**
 * @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 OwnableUpgradeSafe is Initializable, ContextUpgradeSafe {
    address private _owner;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */

    function __Ownable_init() internal initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal initializer {


        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 virtual 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 virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }

    uint256[49] private __gap;
}

// SPDX-License-Identifier: UNLICENSED
interface ICandyFarmDeployer {
    function createCandyFarm(
        address _feesController,
        address _stakedTokenPop,
        address _rewardToken,
        uint256 _bonusTokenAmount,
        uint256 _bonusEndTime,
        address _owner
    ) external returns(address);
}

// SPDX-License-Identifier: UNLICENSED
interface IProxyDeployer {
    function admin() external returns (address);
    function deployProxy(address _logic) external returns (address);
    function deployProxy(address _logic, bytes calldata _data) external returns (address);
}

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
contract ReentrancyGuardUpgradeSafe is Initializable {
    bool private _notEntered;


    function __ReentrancyGuard_init() internal initializer {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal initializer {


        // 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;
    }

    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
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);
}

// SPDX-License-Identifier: MIT
/**
 * @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, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, 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 (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @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) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @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) {
        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, reverting 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) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting 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) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * 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);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * 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);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * 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;
    }
}

// SPDX-License-Identifier: MIT
/**
 * @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) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @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");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        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);
            }
        }
    }
}

// SPDX-License-Identifier: MIT
/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 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 SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
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));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    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. 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, "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");
        }
    }
}

// SPDX-License-Identifier: UNLICENSED
abstract contract IFeesController {
    function feesTo() public view virtual returns (address);
    function setFeesTo(address) public virtual;

    function feesPpm() public view virtual returns (uint);
    function setFeesPpm(uint) public virtual;

    function candyFarmBurnPpm() public view virtual returns (uint);
    function setCandyFarmBurnPpm(uint) public virtual;
}

// SPDX-License-Identifier: UNLICENSED
abstract contract IBurnable {
     function  burn(uint256 _amount) public virtual;
}

// SPDX-License-Identifier: UNLICENSED
// Adapted from Pancakeswap syrup pools
contract CandyFarm is Initializable, OwnableUpgradeSafe, ReentrancyGuardUpgradeSafe {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    uint256 private constant REWARD_PRECISION = 10**9;

    // The precision factor
    uint256 private constant PRECISION_FACTOR_MUL = uint256(10**24);
    uint256 private constant PRECISION_FACTOR_DIV = PRECISION_FACTOR_MUL * REWARD_PRECISION;

    // Accrued token per share
    uint256 private accTokenPerShare;

    // The time when POP mining ends.
    uint256 public endDate;

    // The time when POP mining starts.
    uint256 public startDate;

    // Total reward token amount
    uint256 public rewardTokenAmount;

    // The time of the last pool update
    uint256 public lastRewardTime;

    // POP tokens created per time multiplied by REWARD_PRECISION
    uint256 public rewardPerTime;

    // The reward token
    IERC20 public rewardToken;

    // The staked token
    IERC20 public stakedTokenPop;

    // Fee controller
    IFeesController public feesController;

    // Info of each user that stakes tokens (stakedTokenPop)
    mapping(address => UserInfo) public userInfo;

    struct UserInfo {
        uint256 amount; // How many staked tokens the user has provided
        uint256 rewardDebt; // Reward debt
    }

    event Deposit(address indexed user, uint256 amount);
    event Withdraw(address indexed user, uint256 amount);
    event ExtendDuration(uint256 newEndDate);
    event RewardTokenAmountIncreased(uint256 newRewardAmount);

    modifier isActive() {
        require(endDate > block.timestamp, "Candy farm not active");
        _;
    }

    /**
     * @notice Initialize the contract
     * @param _feesController: fees controller address
     * @param _stakedTokenPop: staked (POP) token address
     * @param _rewardToken: reward token address
     * @param _rewardTokenAmount: reward token amount
     * @param _endDate: end time
     */
    function initialize(
        address _feesController,
        address _stakedTokenPop,
        address _rewardToken,
        uint256 _rewardTokenAmount,
        uint256 _endDate
    ) external initializer {
        require(_endDate > block.timestamp, "Candy farm must be in the future");
        require(_endDate < block.timestamp + 60*60*24*365*10, "Candy farm must last less than 10 years!");
        OwnableUpgradeSafe.__Ownable_init();
        ReentrancyGuardUpgradeSafe.__ReentrancyGuard_init();

        feesController = IFeesController(_feesController);
        stakedTokenPop = IERC20(_stakedTokenPop);
        rewardToken = IERC20(_rewardToken);
        startDate = block.timestamp;
        endDate = _endDate;
        rewardTokenAmount = _rewardTokenAmount;

        rewardPerTime = _rewardTokenAmount.mul(REWARD_PRECISION).div(_endDate - block.timestamp);

        lastRewardTime = block.timestamp;
    }

    /**
     * @notice Deposit staked tokens and collect reward tokens (if any)
     * @param _amount: amount to withdraw (in rewardToken)
     */
    function deposit(uint256 _amount) external nonReentrant {
        UserInfo storage user = userInfo[msg.sender];

        _updatePool();

        if (user.amount > 0) {
            uint256 pending = _getUserPendingReward(user.amount, user.rewardDebt);
            if (pending > 0) {
                rewardToken.safeTransfer(address(msg.sender), pending);
            }
        }

        if (_amount > 0) {
            stakedTokenPop.safeTransferFrom(address(msg.sender), address(this), _amount);
            uint256 stakedAmount = _burnAndReturnStakedAmount(_amount);
            user.amount = user.amount.add(stakedAmount);

            emit Deposit(msg.sender, stakedAmount);
        }

        user.rewardDebt = user.amount.mul(accTokenPerShare).div(PRECISION_FACTOR_DIV);
    }

    /**
     * @notice Withdraw staked tokens and collect reward tokens. To withdraw only reward tokens set function input _amount to 0.
     * @param _amount: amount to withdraw (in rewardToken)
     */
    function withdraw(uint256 _amount) external nonReentrant {
        UserInfo storage user = userInfo[msg.sender];
        require(user.amount >= _amount, "Amount to withdraw too high");

        _updatePool();

        uint256 pending = _getUserPendingReward(user.amount, user.rewardDebt);

        if (_amount > 0) {
            user.amount = user.amount.sub(_amount);
            stakedTokenPop.safeTransfer(address(msg.sender), _amount);
        }

        if (pending > 0) {
            rewardToken.safeTransfer(address(msg.sender), pending);
        }

        user.rewardDebt = user.amount.mul(accTokenPerShare).div(PRECISION_FACTOR_DIV);

        emit Withdraw(msg.sender, _amount);
    }

    /**
     * @notice extend pool duration
     * @param _newEndDate: new end date
     * @return Amount new reward tokens added to keep the same reward rate
     */
    function extendPool(uint256 _newEndDate) external isActive returns(uint256) {
        uint256 newRewardAmount = _extendPoolInternal(_newEndDate);
        rewardToken.safeTransferFrom(msg.sender, address(this), newRewardAmount);
        return newRewardAmount;
    }

    /**
     * @notice extend pool duration
     * @param _newEndDate: new end date
     * @return Amount new reward tokens added to keep the same reward rate
     */
    function _extendPoolInternal(uint256 _newEndDate) internal returns(uint256) {
        require(_newEndDate < block.timestamp + 60*60*24*365*10, "Candy farm must last less than 10 years!");
        uint256 additionalRewardAmount = getAdditionalTokensRequiredToExtend(_newEndDate);

        endDate = _newEndDate;
        rewardTokenAmount = rewardTokenAmount.add(additionalRewardAmount);

        emit ExtendDuration(_newEndDate);
        emit RewardTokenAmountIncreased(rewardTokenAmount);

        return additionalRewardAmount;
    }

    /**
     * @notice Calculate additional amount of tokens needed to extend 
     * @param _newEndDate: new end date
     * @return Additional amount of tokens needed
     */
    function getAdditionalTokensRequiredToExtend(uint256 _newEndDate) public view returns(uint256) {
        uint256 timeDiff = _newEndDate.sub(endDate, "New end date must be larger than before");
        return timeDiff.mul(rewardPerTime).div(REWARD_PRECISION).add(1);
    }

    /**
     * @notice increase reward per time based on new reward tokens added to the pool
     * @param _additionalAmount: additional reward token amount
     */
    function increaseReward(uint256 _additionalAmount) external isActive {
        _increaseRewardInternal(_additionalAmount);
        rewardToken.safeTransferFrom(msg.sender, address(this), _additionalAmount);
    }

    /**
     * @notice increase reward per time based on new reward tokens added to the pool
     * @param _additionalAmount: additional reward token amount
     */
    function _increaseRewardInternal(uint256 _additionalAmount) internal {
        _updatePool();
        
        uint256 additionalRewardPerTime = _additionalAmount.mul(REWARD_PRECISION).div(endDate - block.timestamp);

        rewardPerTime = rewardPerTime.add(additionalRewardPerTime);
        rewardTokenAmount = rewardTokenAmount.add(_additionalAmount);

        emit RewardTokenAmountIncreased(rewardTokenAmount);
    }

    /**
     * @notice increase end date and reward amont
     * @param _newEndDate: new end date
     * @param _additionalAmount: additional reward token amount
     */
    function increaseRewardAndDuration(uint256 _newEndDate, uint256 _additionalAmount) external isActive {
        uint256 extendAmount = _extendPoolInternal(_newEndDate);

        require(_additionalAmount >= extendAmount, "_additionalAmount less than extendAmount");

        uint256 increaseRewardAmount = _additionalAmount.sub(extendAmount);
        _increaseRewardInternal(increaseRewardAmount);

        rewardToken.safeTransferFrom(msg.sender, address(this), _additionalAmount);
    }

    /**
     * @notice Stop rewards
     * @dev Only callable by owner
     */
    function stopReward() external onlyOwner {
        endDate = block.timestamp;
    }

    function resumeReward(uint256 _bonusEndTime) external onlyOwner {
        require(endDate <= block.timestamp, "endDate in the future");
        endDate = _bonusEndTime;
    }

    /**
     * @notice View function to see pending reward on frontend.
     * @param _user: user address
     * @return Pending reward for a given user
     */
    function pendingReward(address _user) external view returns (uint256) {
        UserInfo storage user = userInfo[_user];
        uint256 stakedTokenSupply = stakedTokenPop.balanceOf(address(this));
        if (block.timestamp > lastRewardTime && stakedTokenSupply != 0) {
            uint256 multiplier = _getMultiplier(lastRewardTime, block.timestamp);
            uint256 bonusReward = multiplier.mul(rewardPerTime);
            uint256 adjustedTokenPerShare =
                accTokenPerShare.add(bonusReward.mul(PRECISION_FACTOR_MUL).div(stakedTokenSupply));
            return (user.amount.mul(adjustedTokenPerShare).div(PRECISION_FACTOR_DIV)).sub(user.rewardDebt);
        } else {
            return _getUserPendingReward(user.amount, user.rewardDebt);
        }
    }

    function _getUserPendingReward(uint256 userAmount, uint256 userRewardDebt) private view returns(uint256) {
        return (userAmount.mul(accTokenPerShare).div(PRECISION_FACTOR_DIV)).sub(userRewardDebt);
    }

    /**
     * @notice Update reward variables of the given pool to be up-to-date.
     */
    function _updatePool() internal {
        if (block.timestamp <= lastRewardTime) {
            return;
        }

        uint256 stakedTokenSupply = stakedTokenPop.balanceOf(address(this));

        if (stakedTokenSupply == 0) {
            lastRewardTime = block.timestamp;
            return;
        }

        uint256 multiplier = _getMultiplier(lastRewardTime, block.timestamp);
        uint256 bonusReward = multiplier.mul(rewardPerTime);
        accTokenPerShare = accTokenPerShare.add(bonusReward.mul(PRECISION_FACTOR_MUL).div(stakedTokenSupply));
        lastRewardTime = block.timestamp;
    }

    /**
     * @notice Burn percentage of tokens and return the remainder
     * @param _amount: Amount before burn
     * @return Amount after burn
     */
    function _burnAndReturnStakedAmount(uint256 _amount) private returns(uint256) {
        // Calculate burn amount
        uint256 burnAmount = _amount.mul(feesController.candyFarmBurnPpm()).div(1000);

        // Burn
        IBurnable(address(stakedTokenPop)).burn(burnAmount);

        // Return amount after fees 
        return _amount.sub(burnAmount);
    }

    /**
     * @notice Return reward multiplier over the given _from to _to time.
     * @param _from: time to start
     * @param _to: time to finish
     */
    function _getMultiplier(uint256 _from, uint256 _to) internal view returns (uint256) {
        if (_to <= endDate) {
            return _to.sub(_from);
        } else if (_from >= endDate) {
            return 0;
        } else {
            return endDate.sub(_from);
        }
    }
}

// SPDX-License-Identifier: UNLICENSED
contract CandyFarmDeployer is ICandyFarmDeployer {
    IProxyDeployer public immutable proxyDeployer;
    address public candyFarmImpl;

    modifier isAdmin() {
        require(msg.sender == proxyDeployer.admin(), "isAdmin: Caller not an admin!");
        _;
    }

    constructor(IProxyDeployer _proxyDeployer, address _candyFarmImpl) public {
        require(address(_proxyDeployer) != address(0), "constructor: _proxyDeployer is zero");
        require(_candyFarmImpl != address(0), "constructor: _candyFarmImpl is zero");
        proxyDeployer = _proxyDeployer;
        candyFarmImpl = _candyFarmImpl;
    }

    function createCandyFarm(
        address _feesController,
        address _stakedTokenPop,
        address _rewardToken,
        uint256 _bonusTokenAmount,
        uint256 _bonusEndTime,
        address _owner
    ) external override returns(address) {
        CandyFarm newCandyFarm = deployProxy();

        newCandyFarm.initialize(
            _feesController,
            _stakedTokenPop,
            _rewardToken,
            _bonusTokenAmount,
            _bonusEndTime
        );

        newCandyFarm.transferOwnership(_owner);

        return address(newCandyFarm);
    }

    function deployProxy() private returns(CandyFarm) {
        address mlpProxyAddress = proxyDeployer.deployProxy(candyFarmImpl);
        return CandyFarm(mlpProxyAddress);
    }

    function changeImplementation(address _impl) external isAdmin {
        require(_impl != address(0), "changeImplementation: _impl is zero");
        candyFarmImpl = _impl;
    }
}
{"success": true, "error": null, "results": {"detectors": [{"check": "reentrancy-no-eth", "impact": "Medium", "confidence": "Medium"}, {"check": "incorrect-equality", "impact": "Medium", "confidence": "High"}]}}