// File: contracts/AURAStaking.sol



// SPDX-License-Identifier: MIT
// Author: Sobi (Ciphers)

pragma solidity ^0.8.4;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/security/Pausable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/Address.sol"; //library
import "./AURAStakingInterfaces.sol";

error InsufficientBalance();
error InsufficientRewardsInPool();
error ActiveUser(uint256);
error TimeIncorrect();
error ContractAddressInvalid();
error AlreadyStaked();
error StakeYourAmount();
error InsufficientStakes();
error AlreadyUnstaked();
error NotExpiredYet();
error UnStakeFirst();
error InvalidUser();

contract AURAStaking is
    Ownable,
    Pausable,
    ReentrancyGuard,
    UserStats,
    Reward,
    Staking
{
    using Address for address;

    struct userStats {
        uint256 expiry; //the time of stake (update once withdrawal or stake)
        uint256 since; //The time on which the stakes are gettitng expired
        uint256 currentlyStaked; //Pending Withdrawal (update when stake & withdrawal)
        uint256 totalWithdrawal; //Total Withdraw of staked amount (update when withdrawal)
        uint256 totalPendingReward; //Pending Claim reward
        uint256 totalAccumulatedReward; //Withdrawn claim reward  (update when claimed)
        uint256 lockingPeriod; //Time in Seconds of the locking time
        bool unstake; //once the users has unstaked they can withdraw after 7 days it's all amount
    }

    IERC20 public token;
    uint256 APR;
    uint256 minStakingAmount;
    uint256 allocatedReward;
    uint256 totalStakedInPool;
    uint256 totalDelegates;
    mapping(address => userStats) user;

    constructor(
        IERC20 _token,
        uint256 _APR,
        uint256 _MinStakingAmount
    ) {
        require(address(_token) != address(0), "The address is not correct");
        token = _token;
        APR = _APR;
        minStakingAmount = _MinStakingAmount;
    }

    function pause() public onlyOwner {
        _pause();
    }

    function unPause() public onlyOwner {
        _unpause();
    }

    function CurrentAPR() public view override returns (uint256) {
        return APR;
    }

    function ChangeAPR(uint256 _APR) public override onlyOwner returns (bool) {
        APR = _APR;
        return true;
    }

    function ChangeMinStakingAmount(uint256 _MinAmount)
        public
        override
        onlyOwner
        returns (bool)
    {
        minStakingAmount = _MinAmount;
        return true;
    }

    function MinStakingAmount() public view override returns (uint256) {
        return minStakingAmount;
    }

    //The total rewards remaining in the pool. These rewards are reserved for the new users that are going to stake into the pool.
    function AllocationOfRewards() public view override returns (uint256) {
        return allocatedReward;
    }

    function IncreaseAllocationReward(uint256 _amount)
        public
        override
        onlyOwner
        returns (bool)
    {
        allocatedReward += _amount;
        token.transferFrom(msg.sender, address(this), _amount);
        return true;
    }

    function DecreaseAllocationReward(uint256 _amount)
        public
        override
        onlyOwner
        returns (bool)
    {
        allocatedReward -= _amount;
        token.transfer(msg.sender, _amount);
        return true;
    }

    function TransferAllocatedRewardFromContractToOwner(uint256 _amount)
        public
        override
        onlyOwner
        returns (bool)
    {
        token.transfer(msg.sender, _amount);
        return true;
    }

    //If someone sends Ethers mistakenly
    function withdrawEther() public onlyOwner nonReentrant returns (bool) {
        (bool success, ) = msg.sender.call{value: address(this).balance}("");
        return success;
    }

    function checkContractValidity() public view returns (bool) {
        return address(this).isContract();
    }

    //Re-Fund scenario
    function EmergencyWithdrawal(address _user, uint256 _amount)
        public
        override
        onlyOwner
        returns (bool)
    {
        token.transfer(_user, _amount);
        return true;
    }

    function TotalWithdrawal(address _user)
        public
        view
        override
        returns (uint256)
    {
        return user[_user].totalWithdrawal;
    }

    function TotalPendingReward(address _user)
        public
        view
        override
        returns (uint256)
    {
        return user[_user].totalPendingReward;
    }

    function TotalAccumulatedReward(address _user)
        public
        view
        override
        returns (uint256)
    {
        return user[_user].totalAccumulatedReward;
    }

    function CalculateReward(uint256 _amount, uint256 _time)
        public
        view
        override
        returns (uint256)
    {
        return ((_time * _amount * APR) / 365 days) / 100;
    }

    //Number of users staked in the Staking Pool
    function TotalDelegates() public view override returns (uint256) {
        return totalDelegates;
    }

    //The user's Current status of the stakes
    function CurrentlyStaked(address _user)
        public
        view
        override
        returns (uint256)
    {
        return user[_user].currentlyStaked;
    }

    //The user's current status of the stakes is whether active?
    function HasStake(address _user) public view override returns (bool) {
        if (user[_user].currentlyStaked == 0) {
            return false;
        }
        return true;
    }

    function userSTATS(address _user) public view onlyOwner() returns(userStats memory){
       return user[_user];
    }


    //Total stakes in the pool status
    function TotalStakedInPool() public view override returns (uint256) {
        return totalStakedInPool;
    }

    //pause it when finished
    function Stake(uint256 amount, uint256 time)
        public
        override
        whenNotPaused
        returns (bool)
    {
        uint256 RewardOFUser = CalculateReward(amount, time);
        if (
            token.balanceOf(_msgSender()) < (amount) ||
            amount < minStakingAmount
        ) revert InsufficientBalance();
        if (time < 1209600 || time > 31536000) revert TimeIncorrect();
        if (user[_msgSender()].currentlyStaked == 0) {
            unchecked {
                ++totalDelegates;
            }
        }
        if (AllocationOfRewards() < RewardOFUser)
            revert InsufficientRewardsInPool();

        if (user[_msgSender()].since > 0) revert AlreadyStaked();
        _stake(amount, time, RewardOFUser);
        totalStakedInPool += amount ;
        emit User_Staked(
            _msgSender(),
            amount,
            user[_msgSender()].lockingPeriod
        );
        return true;
    }

    function _stake(
        uint256 _amount,
        uint256 _time,
        uint256 _reward
    ) internal {
        user[_msgSender()].since = block.timestamp;
        user[_msgSender()].expiry = block.timestamp + _time;
        user[_msgSender()].currentlyStaked += _amount;
        user[_msgSender()].totalPendingReward += _reward;
        user[_msgSender()].lockingPeriod += _time;
        allocatedReward -= _reward;
        token.transferFrom(_msgSender(), address(this), _amount);
    }

    function ReStake(uint256 amount, uint256 time)
        public
        override
        whenNotPaused
        returns (bool)
    {
        uint256 RewardOFUser = 
            CalculateReward(
                (user[_msgSender()].currentlyStaked + amount ),
                time
            );
        if (
            token.balanceOf(_msgSender()) < ( amount) ||
            amount < minStakingAmount
        ) revert InsufficientBalance();
        if (time < 1209600 || time > 31536000) revert TimeIncorrect();
        if (user[_msgSender()].currentlyStaked == 0) {
            unchecked {
                ++totalDelegates;
            }
        }
        if (AllocationOfRewards() < RewardOFUser)
            revert InsufficientRewardsInPool();

        if (user[_msgSender()].since == 0) revert StakeYourAmount();
        _reStake(amount, time, RewardOFUser);
        totalStakedInPool += amount ;
        emit User_ReStaked(
            _msgSender(),
            amount,
            user[_msgSender()].lockingPeriod,
            user[_msgSender()].currentlyStaked
        );
        return true;
    }

    function _reStake(
        uint256 _amount,
        uint256 _time,
        uint256 _reward
    ) internal {
        user[_msgSender()].expiry = (_time + user[_msgSender()].expiry);
        user[_msgSender()].currentlyStaked += _amount;
        user[_msgSender()].totalPendingReward += _reward;
        user[_msgSender()].unstake = false;
        user[_msgSender()].lockingPeriod += _time;
        allocatedReward -= _reward;
        token.transferFrom(_msgSender(), address(this), _amount);
    }

    //A user can withdraw after 7 days of unstaking it's amount.
    function UnStake() public override whenNotPaused returns (bool) {
        if (user[_msgSender()].unstake == true) revert AlreadyUnstaked();
        if (user[_msgSender()].currentlyStaked == 0)
            revert InsufficientStakes();
        if (user[_msgSender()].expiry > block.timestamp) revert NotExpiredYet();
        _unStake();
        emit User_Unstake(
            _msgSender(),
            user[_msgSender()].currentlyStaked,
            user[_msgSender()].expiry
        );
        return true;
    }

    function _unStake() internal {
        user[_msgSender()].expiry += 604800; //7 days
        user[_msgSender()].unstake = true;
        totalDelegates--;
    }

    function Withdraw() public override whenNotPaused returns (bool) {
        if (user[_msgSender()].unstake == false) revert UnStakeFirst();
        if (user[_msgSender()].expiry > block.timestamp) revert NotExpiredYet();
        if (user[_msgSender()].currentlyStaked <= 0) revert NotExpiredYet();
        _withdraw();
        emit User_Withdraw(_msgSender(), user[_msgSender()].totalWithdrawal);
        return true;
    }

    function _withdraw() internal {
        user[_msgSender()].totalWithdrawal = user[_msgSender()].currentlyStaked;
        token.transfer(msg.sender, user[_msgSender()].currentlyStaked);
        user[_msgSender()].since = 0;
        user[_msgSender()].currentlyStaked = 0;
        if (
            user[_msgSender()].totalPendingReward == 0 &&
            user[_msgSender()].currentlyStaked == 0
        ) {
            delete user[_msgSender()];
        }
    }

    function Claim() public override returns (bool) {
        if (user[_msgSender()].totalPendingReward == 0) revert InvalidUser();
        _claim();
        return true;
    }

    function _claim() internal {
        uint256 rewardPerSecond = (user[_msgSender()].totalPendingReward /
            user[_msgSender()].lockingPeriod);
        uint256 rewardTillToday = block.timestamp - user[_msgSender()].since;
        uint256 claim = rewardPerSecond * rewardTillToday;

        if (block.timestamp >= user[_msgSender()].expiry) {
            token.transfer(msg.sender, user[_msgSender()].totalPendingReward);
            emit User_Claim(
                _msgSender(),
                user[_msgSender()].totalPendingReward,
                0
            );
            user[_msgSender()].totalAccumulatedReward += user[_msgSender()]
                .totalPendingReward;
            user[_msgSender()].totalPendingReward = 0;
        } else {
            token.transfer(msg.sender, claim);
            user[_msgSender()].totalAccumulatedReward += claim;
            user[_msgSender()].totalPendingReward -= claim;
            emit User_Claim(
                _msgSender(),
                claim,
                user[_msgSender()].totalPendingReward
            );
        }

        if (
            user[_msgSender()].totalPendingReward == 0 &&
            user[_msgSender()].currentlyStaked == 0
        ) {
            delete user[_msgSender()];
        }
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @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/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

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

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @openzeppelin/contracts/security/Pausable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// File: @openzeppelin/contracts/security/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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;
    }
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @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
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 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/AURAStakingInterfaces.sol



// SPDX-License-Identifier: MIT
// Author: Sobi (Ciphers)

pragma solidity ^0.8.0;

interface UserStats {
    function TotalDelegates() external view returns (uint256);

    function CurrentlyStaked(address) external view returns (uint256);

    function TotalWithdrawal(address) external view returns (uint256);

    function TotalPendingReward(address) external view returns (uint256);

    function TotalAccumulatedReward(address) external view returns (uint256);

    function HasStake(address) external view returns (bool);
}

interface Reward {
    function CurrentAPR() external view returns (uint256);

    function TotalStakedInPool() external view returns (uint256);

    function MinStakingAmount() external view returns (uint256);

    function IncreaseAllocationReward(uint256) external returns (bool);

    function DecreaseAllocationReward(uint256) external returns (bool);

    function TransferAllocatedRewardFromContractToOwner(uint256 amount)
        external
        returns (bool);

    function AllocationOfRewards() external view returns (uint256); //Current status of rewrads to give remaining in the pool

    function ChangeAPR(uint256) external returns (bool);

    function ChangeMinStakingAmount(uint256) external returns (bool);
}

interface Staking {
    function CalculateReward(uint256, uint256) external view returns (uint256);

    function Stake(uint256, uint256) external returns (bool);

    function ReStake(uint256, uint256) external returns (bool);

    function UnStake() external returns (bool);

    function Withdraw() external returns (bool);

    function Claim() external returns (bool);

    function EmergencyWithdrawal(address _user, uint256 _amount)
        external
        returns (bool);

    event User_Staked(
        address indexed userAddress,
        uint256 indexed amount,
        uint256 indexed lockingPeriod
    );
    event User_ReStaked(
        address indexed userAddress,
        uint256 indexed amount,
        uint256 indexed lockingPeriod,
        uint256 totalStakedStatus
    );
    event User_Withdraw(
        address indexed userAddress,
        uint256 indexed withdrawaAmount
    );
    event User_Unstake(
        address indexed userAddress,
        uint256 indexed amount,
        uint256 indexed withdrawalTime
    );
    event User_Claim(
        address indexed userAddress,
        uint256 indexed claimAmount,
        uint256 pendingReward
    );
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}