// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IERC20 {
    /**
     * @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 contracts/IERC20Mintable.sol

pragma solidity ^0.8.0;
interface IERC20Mintable is IERC20 {
    function mint(address to, uint256 amount) external;
    function transferOwnership(address newOwner) external;
}


// File @openzeppelin/contracts/utils/math/SafeMath.sol@v4.4.0
// OpenZeppelin Contracts v4.4.0 (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
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) {
        unchecked {
            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) {
        unchecked {
            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) {
        unchecked {
            // 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) {
        unchecked {
            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) {
        unchecked {
            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) {
        return a + b;
    }

    /**
     * @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 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) {
        return a * b;
    }

    /**
     * @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.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        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) {
        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) {
        unchecked {
            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.
     *
     * 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) {
        unchecked {
            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) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}


// File @openzeppelin/contracts/utils/Address.sol@v4.4.0

// OpenZeppelin Contracts v4.4.0 (utils/Address.sol)

pragma solidity ^0.8.0;

/**
 * @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;
        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");

        (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");

        (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");

        (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");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal 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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}


// File contracts/SafeERC20.sol

pragma solidity ^0.8.0;
/**
 * @title SafeERC20
 * @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 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: BEP20 operation did not succeed");
        }
    }
}


// File @openzeppelin/contracts/utils/Context.sol@v4.4.0

// OpenZeppelin Contracts v4.4.0 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}


// File @openzeppelin/contracts/access/Ownable.sol@v4.4.0

// OpenZeppelin Contracts v4.4.0 (access/Ownable.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual 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 {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}


// File @openzeppelin/contracts/security/ReentrancyGuard.sol@v4.4.0

// OpenZeppelin Contracts v4.4.0 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @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].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being 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 percentage 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.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @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 making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}


pragma solidity ^0.8.0;
contract Reserve is Ownable {
    function safeTransfer(
        IERC20 rewardToken,
        address _to,
        uint256 _amount
    ) external onlyOwner {
        uint256 tokenBal = rewardToken.balanceOf(address(this));
        if (_amount > tokenBal) {
            rewardToken.transfer(_to, tokenBal);
        } else {
            rewardToken.transfer(_to, _amount);
        }
    }
}

contract Staking is Ownable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    struct WithdrawFeeInterval {
        uint256 day;
        uint256 fee;
    }

    struct UserInfo {
        uint256 amount;
        uint256 rewardDebt;
        uint256 rewardLockedUp;
        uint256 nextHarvestUntil;
        uint256 depositTimestamp;
    }

    struct PoolInfo {
        IERC20 stakedToken;
        IERC20 rewardToken;
        uint256 stakedAmount;
        uint256 rewardSupply;
        uint256 tokenPerBlock;
        uint256 lastRewardBlock;
        uint256 accTokenPerShare;
        uint16 depositFeeBP;
        uint256 minDeposit;
        uint256 harvestInterval;
        bool lockDeposit;
    }

    Reserve public rewardReserve;
    uint256 public constant BONUS_MULTIPLIER = 1;
    uint256 public constant MAXIMUM_HARVEST_INTERVAL = 14 days;

    mapping(address => mapping(address => bool)) internal poolExists;
    mapping(uint256 => uint256) public rewardDistributions;

    PoolInfo[] public poolInfo;
    mapping(uint256 => mapping(address => UserInfo)) public userInfo;
    mapping(uint256 => WithdrawFeeInterval[]) public withdrawFee;
    uint256 public startBlock;
    bool public paused = true;
    bool public initialized = false;

    event Deposit(address indexed user, uint256 indexed pid, uint256 amount);
    event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);
    event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);
    event RewardLockedUp(address indexed user, uint256 indexed pid, uint256 amountLockedUp);
    event PoolUpdated(uint256 tokenPerBlock, uint256 depositFee, uint256 minDeposit, uint256 harvestInterval);
    event RewardTokenDeposited(address depositer, uint256 pid, uint256 amount);
    event AdminEmergencyWithdraw(uint256 pid, uint256 currentRewardBalance, uint256 accTokenPerShare, uint256 tokenPerBlock, uint256 lastRewardBlock);
    event PoolPausedUpdated(bool paused);
    event DepositLocked(uint256 pid, bool depositLocked);

    constructor() {
        startBlock = 0;
        rewardReserve = new Reserve();
        WithdrawFeeInterval[] memory _withdrawFee = new WithdrawFeeInterval[](5);
        _withdrawFee[0] = WithdrawFeeInterval(30 days, 250);
        _withdrawFee[1] = WithdrawFeeInterval(60 days, 200);
        _withdrawFee[2] = WithdrawFeeInterval(74 days, 150);
        _withdrawFee[3] = WithdrawFeeInterval(90 days, 75);
        add(95e15, IERC20(0x1322310635cc6bB6435E70120c563535e3D0CF86), IERC20(0x1322310635cc6bB6435E70120c563535e3D0CF86), 0, 0, 0, _withdrawFee);
    }

    function initialize() external onlyOwner {
        require(!initialized, "STAKING: Staking already started!");
        initialized = true;
        paused = false;
        startBlock = block.number;
        uint256 length = poolInfo.length;
        for (uint256 pid = 0; pid < length; ++pid) {
            poolInfo[pid].lastRewardBlock = startBlock;
        }
    }

    function getWithdrawFeeIntervals(uint256 poolId) external view returns (WithdrawFeeInterval[] memory) {
        return withdrawFee[poolId];
    }

    function poolLength() external view returns (uint256) {
        return poolInfo.length;
    }

    function add(
        uint256 _tokenPerBlock,
        IERC20 _stakedToken,
        IERC20 _rewardToken,
        uint16 _depositFeeBP,
        uint256 _minDeposit,
        uint256 _harvestInterval,
        WithdrawFeeInterval[] memory withdrawFeeIntervals
    ) public onlyOwner {
        require(address(_stakedToken) != address(0), "STAKING: Invalid Staked token address");
        require(address(_rewardToken) != address(0), "STAKING: Invalid Reward token address");
        require(poolInfo.length <= 1000, "STAKING: Pool Length Full!");
        require(!poolExists[address(_stakedToken)][address(_rewardToken)], "STAKING: Pool Already Exists!");
        require(_depositFeeBP <= 10000, "STAKING: invalid deposit fee basis points");
        require(_harvestInterval <= MAXIMUM_HARVEST_INTERVAL, "STAKING: invalid harvest interval");

        uint256 lastRewardBlock = block.number > startBlock ? block.number : startBlock;
        poolInfo.push(
            PoolInfo({
                stakedToken: _stakedToken,
                rewardToken: _rewardToken,
                stakedAmount: 0,
                rewardSupply: 0,
                tokenPerBlock: _tokenPerBlock,
                lastRewardBlock: lastRewardBlock,
                accTokenPerShare: 0,
                depositFeeBP: _depositFeeBP,
                minDeposit: _minDeposit,
                harvestInterval: _harvestInterval,
                lockDeposit: false
            })
        );
        uint256 length = withdrawFeeIntervals.length;
        for (uint256 i = 0; i < length; i++) {
            withdrawFee[poolInfo.length - 1].push(withdrawFeeIntervals[i]);
        }
        poolExists[address(_stakedToken)][address(_rewardToken)] = true;
    }

    function set(
        uint256 _pid,
        uint256 _tokenPerBlock,
        uint16 _depositFeeBP,
        uint256 _minDeposit,
        uint256 _harvestInterval
    ) external onlyOwner {
        require(_depositFeeBP <= 10000, "STAKING: invalid deposit fee basis points");
        require(_harvestInterval <= MAXIMUM_HARVEST_INTERVAL, "STAKING: invalid harvest interval");

        poolInfo[_pid].tokenPerBlock = _tokenPerBlock;
        poolInfo[_pid].depositFeeBP = _depositFeeBP;
        poolInfo[_pid].minDeposit = _minDeposit;
        poolInfo[_pid].harvestInterval = _harvestInterval;

        emit PoolUpdated(_tokenPerBlock, _depositFeeBP, _minDeposit, _harvestInterval);
    }

    function setWithdrawFeeInterval(uint256 poolId, uint256 index, WithdrawFeeInterval memory _withdrawFeeInterval) external onlyOwner {
        if(index < withdrawFee[poolId].length)
            withdrawFee[poolId][index] = _withdrawFeeInterval;
        else
            withdrawFee[poolId].push(_withdrawFeeInterval);
    }

    function getMultiplier(uint256 _from, uint256 _to) public pure returns (uint256) {
        return _to.sub(_from).mul(BONUS_MULTIPLIER);
    }

    function pendingToken(uint256 _pid, address _user) external view returns (uint256) {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][_user];
        uint256 accTokenPerShare = pool.accTokenPerShare;
        if (
            block.number > pool.lastRewardBlock &&
            pool.stakedAmount != 0 &&
            pool.rewardToken.balanceOf(address(this)) > 0
        ) {
            uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
            uint256 tokenReward = multiplier.mul(pool.tokenPerBlock);
            accTokenPerShare = accTokenPerShare.add(tokenReward.mul(1e12).div(pool.stakedAmount));
        }
        return user.amount.mul(accTokenPerShare).div(1e12).sub(user.rewardDebt);
    }

    function canHarvest(uint256 _pid, address _user) public view returns (bool) {
        UserInfo storage user = userInfo[_pid][_user];
        return user.amount != 0 && block.timestamp >= user.nextHarvestUntil;
    }

    function updatePool(uint256 _pid) public {
        PoolInfo storage pool = poolInfo[_pid];
        if (block.number <= pool.lastRewardBlock) {
            return;
        }
        uint256 tokenBalance = pool.stakedAmount;
        if (tokenBalance == 0 || pool.tokenPerBlock == 0) {
            pool.lastRewardBlock = block.number;
            return;
        }

        uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
        uint256 tokenReward = multiplier.mul(pool.tokenPerBlock);
        uint256 rewardTokenSupply = pool.rewardSupply;
        uint256 reward = tokenReward > rewardTokenSupply ? rewardTokenSupply : tokenReward;
        if (reward > 0) {
            pool.rewardSupply -= reward;
            pool.accTokenPerShare = pool.accTokenPerShare.add(reward.mul(1e12).div(tokenBalance));
        }
        pool.lastRewardBlock = block.number;
    }

    function depositRewardToken(uint256 poolId, uint256 amount) external {
        PoolInfo storage _poolInfo = poolInfo[poolId];
        uint256 initialBalance = _poolInfo.rewardToken.balanceOf(address(rewardReserve));
        _poolInfo.rewardToken.safeTransferFrom(msg.sender, address(rewardReserve), amount);
        uint256 finalBalance = _poolInfo.rewardToken.balanceOf(address(rewardReserve));
        _poolInfo.rewardSupply += finalBalance.sub(initialBalance);

        emit RewardTokenDeposited(msg.sender, poolId, amount);
    }

    function deposit(uint256 _pid, uint256 _amount) external {
        require(!paused, "STAKING: Paused!");
        PoolInfo storage pool = poolInfo[_pid];
        require(!pool.lockDeposit, "STAKING: Deposit Locked!");
        UserInfo storage user = userInfo[_pid][msg.sender];
        updatePool(_pid);
        payOrLockupPendingToken(_pid);
        if (_amount > 0) {
            require(_amount >= poolInfo[_pid].minDeposit, "STAKING: Not Enough Required Staking Tokens!");
            user.depositTimestamp = block.timestamp;
            uint256 initialBalance = pool.stakedToken.balanceOf(address(this));
            pool.stakedToken.safeTransferFrom(address(msg.sender), address(this), _amount);
            uint256 finalBalance = pool.stakedToken.balanceOf(address(this));
            uint256 delta = finalBalance.sub(initialBalance);
            if (pool.depositFeeBP > 0) {
                uint256 depositFee = _amount.mul(pool.depositFeeBP).div(10000);
                pool.stakedToken.safeTransfer(owner(), depositFee);
                user.amount = user.amount.add(delta).sub(depositFee);
                pool.stakedAmount = pool.stakedAmount.add(delta).sub(depositFee);
            } else {
                user.amount = user.amount.add(delta);
                pool.stakedAmount = pool.stakedAmount.add(delta);
            }
        }
        user.rewardDebt = user.amount.mul(pool.accTokenPerShare).div(1e12);
        emit Deposit(msg.sender, _pid, _amount);
    }

    function withdraw(uint256 _pid, uint256 _amount) external {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][msg.sender];
        require(user.amount >= _amount, "STAKING: withdraw not good");
        updatePool(_pid);
        payOrLockupPendingToken(_pid);
        uint256 amountToTransfer = _amount;
        if (_amount > 0) {
            user.amount = user.amount.sub(_amount);
            uint256 _withdrawFee = getWithdrawFee(_pid, user.depositTimestamp);
            uint256 feeAmount = _amount.mul(_withdrawFee).div(1000);
            amountToTransfer = _amount.sub(feeAmount);
            pool.stakedAmount = pool.stakedAmount.sub(_amount);
            pool.stakedToken.safeTransfer(owner(), feeAmount);
            pool.stakedToken.safeTransfer(address(msg.sender), amountToTransfer);
        }
        user.rewardDebt = user.amount.mul(pool.accTokenPerShare).div(1e12);
        emit Withdraw(msg.sender, _pid, amountToTransfer);
    }

    function payOrLockupPendingToken(uint256 _pid) internal {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][msg.sender];

        if (user.nextHarvestUntil == 0) {
            user.nextHarvestUntil = block.timestamp.add(pool.harvestInterval);
        }

        uint256 pending = user.amount.mul(pool.accTokenPerShare).div(1e12).sub(user.rewardDebt);
        if (canHarvest(_pid, msg.sender)) {
            if (pending > 0 || user.rewardLockedUp > 0) {
                uint256 totalRewards = pending.add(user.rewardLockedUp);

                user.rewardLockedUp = 0;
                user.nextHarvestUntil = block.timestamp.add(pool.harvestInterval);

                rewardReserve.safeTransfer(pool.rewardToken, msg.sender, totalRewards);
                rewardDistributions[_pid] = rewardDistributions[_pid].add(totalRewards);
            }
        } else if (pending > 0) {
            user.rewardLockedUp = user.rewardLockedUp.add(pending);
            emit RewardLockedUp(msg.sender, _pid, pending);
        }
    }

    function getWithdrawFee(uint256 poolId, uint256 stakedTime) public view returns (uint256) {
        uint256 depositTime = block.timestamp.sub(stakedTime);
        WithdrawFeeInterval[] storage _withdrawFee = withdrawFee[poolId];
        uint256 length = _withdrawFee.length;
        for (uint256 i = 0; i < length; i++) {
            if (depositTime <= _withdrawFee[i].day) return _withdrawFee[i].fee;
        }
        return 0;
    }

    function emergencyWithdraw(uint256 _pid) external {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][msg.sender];
        uint256 amount = user.amount;
        require(amount != 0, "STAKING: Not enought staked tokens!");
        pool.stakedToken.safeTransfer(address(msg.sender), amount);
        emit EmergencyWithdraw(msg.sender, _pid, amount);
        delete userInfo[_pid][msg.sender];
    }

    function emergencyAdminWithdraw(uint256 _pid) external onlyOwner {
        PoolInfo storage pool = poolInfo[_pid];
        uint256 balanceToWithdraw = pool.rewardToken.balanceOf(address(this));
        require(balanceToWithdraw != 0, "STAKING: Not enough balance to withdraw!");
        pool.rewardToken.transfer(owner(), balanceToWithdraw);
        rewardReserve.safeTransfer(pool.rewardToken, owner(), pool.rewardToken.balanceOf(address(rewardReserve)));
        emit AdminEmergencyWithdraw(_pid, pool.rewardToken.balanceOf(address(this)), pool.accTokenPerShare, pool.tokenPerBlock, pool.lastRewardBlock);
        delete poolInfo[_pid];
    }

    function updatePaused(bool _value) external onlyOwner {
        paused = _value;
        emit PoolPausedUpdated(_value);
    }

    function setLockDeposit(uint256 pid, bool locked) external onlyOwner {
        poolInfo[pid].lockDeposit = locked;
        emit DepositLocked(pid, locked);
    }
}