// Contract: ENOStaking
// Target function: function stakeToken(uint _amount, address _referralAddress) external nonReentrant
 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);
    }

    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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

/**
 * @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 make 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;
    }
}


/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface ERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

/*
 * @dev 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) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

/**
 * @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() {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), 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 {
        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;
    }
}



contract ENOStaking is Ownable, ReentrancyGuard {
    using SafeMath for uint;
    using SafeMath for uint256;
    using SafeMath for uint8;



    struct Stake{
        uint deposit_amount;        //Deposited Amount
        uint stake_creation_time;   //The time when the stake was created
        bool returned;              //Specifies if the funds were withdrawed
        uint alreadyWithdrawedAmount;   //TODO Correct Lint
    }


    struct Account{
        address referral;
        uint referralAlreadyWithdrawed;
    }


    //---------------------------------------------------------------------
    //-------------------------- EVENTS -----------------------------------
    //---------------------------------------------------------------------


    /**
    *   @dev Emitted when the pot value changes
     */
    event PotUpdated(
        uint newPot
    );


    /**
    *   @dev Emitted when a customer tries to withdraw an amount
    *       of token greater than the one in the pot
     */
    event PotExhausted(

    );


    /**
    *   @dev Emitted when a new stake is issued
     */
    event NewStake(
        uint stakeAmount,
        address from
    );

    /**
    *   @dev Emitted when a new stake is withdrawed
     */
    event StakeWithdraw(
        uint stakeID,
        uint amount
    );

    /**
    *   @dev Emitted when a referral reward is sent
     */
    event referralRewardSent(
        address account,
        uint reward
    );

    event rewardWithdrawed(
        address account
    );


    /**
    *   @dev Emitted when the machine is stopped (500.000 tokens)
     */
    event machineStopped(
    );

    /**
    *   @dev Emitted when the subscription is stopped (400.000 tokens)
     */
    event subscriptionStopped(
    );



    //--------------------------------------------------------------------
    //-------------------------- GLOBALS -----------------------------------
    //--------------------------------------------------------------------

    mapping (address => Stake[]) private stake; /// @dev Map that contains account's stakes

    address private tokenAddress;

    ERC20 private ERC20Interface;

    uint private pot;    //The pot where token are taken

    uint256 private amount_supplied;    //Store the remaining token to be supplied

    uint private pauseTime;     //Time when the machine paused
    uint private stopTime;      //Time when the machine stopped




    // @dev Mapping the referrals
    mapping (address => address[]) private referral;    //Store account that used the referral

    mapping (address => Account) private account_referral;  //Store the setted account referral


    address[] private activeAccounts;   //Store both staker and referer address


    uint256 private constant _DECIMALS = 18;

    uint256 private constant _INTEREST_PERIOD = 1 days;    //One Month
    uint256 private constant _INTEREST_VALUE = 333;    //0.333% per day

    uint256 private constant _PENALTY_VALUE = 20;    //20% of the total stake



    uint256 private constant _MIN_STAKE_AMOUNT = 100 * (10**_DECIMALS);

    uint256 private constant _MAX_STAKE_AMOUNT = 100000 * (10**_DECIMALS);

    uint private constant _REFERALL_REWARD = 333; //0.333% per day

    uint256 private constant _MAX_TOKEN_SUPPLY_LIMIT =     50000000 * (10**_DECIMALS);
    uint256 private constant _MIDTERM_TOKEN_SUPPLY_LIMIT = 40000000 * (10**_DECIMALS);


    constructor() {
        pot = 0;
        amount_supplied = _MAX_TOKEN_SUPPLY_LIMIT;    //The total amount of token released
        tokenAddress = address(0);
    }

    //--------------------------------------------------------------------
    //-------------------------- TOKEN ADDRESS -----------------------------------
    //--------------------------------------------------------------------


    function setTokenAddress(address _tokenAddress) external onlyOwner {
        require(Address.isContract(_tokenAddress), "The address does not point to a contract");

        tokenAddress = _tokenAddress;
        ERC20Interface = ERC20(tokenAddress);
    }

    function isTokenSet() external view returns (bool) {
        if(tokenAddress == address(0))
            return false;
        return true;
    }

    function getTokenAddress() external view returns (address){
        return tokenAddress;
    }

    //--------------------------------------------------------------------
    //-------------------------- ONLY OWNER -----------------------------------
    //--------------------------------------------------------------------


    function depositPot(uint _amount) external onlyOwner nonReentrant {
        require(tokenAddress != address(0), "The Token Contract is not specified");

        pot = pot.add(_amount);

        if(ERC20Interface.transferFrom(msg.sender, address(this), _amount)){
            //Emit the event to update the UI
            emit PotUpdated(pot);
        }else{
            revert("Unable to tranfer funds");
        }

    }


    function returnPot(uint _amount) external onlyOwner nonReentrant{
        require(tokenAddress != address(0), "The Token Contract is not specified");
        require(pot.sub(_amount) >= 0, "Not enough token");

        pot = pot.sub(_amount);

        if(ERC20Interface.transfer(msg.sender, _amount)){
            //Emit the event to update the UI
            emit PotUpdated(pot);
        }else{
            revert("Unable to tranfer funds");
        }

    }


    function finalShutdown() external onlyOwner nonReentrant{

        uint machineAmount = getMachineBalance();

        if(!ERC20Interface.transfer(owner(), machineAmount)){
            revert("Unable to transfer funds");
        }
        //Goodbye
    }

    function getAllAccount() external onlyOwner view returns (address[] memory){
        return activeAccounts;
    }

    /**
    *   @dev Check if the pot has enough balance to satisfy the potential withdraw
     */
    function getPotentialWithdrawAmount() external onlyOwner view returns (uint){
        uint accountNumber = activeAccounts.length;

        uint potentialAmount = 0;

        for(uint i = 0; i<accountNumber; i++){

            address currentAccount = activeAccounts[i];

            potentialAmount = potentialAmount.add(calculateTotalRewardReferral(currentAccount));    //Referral

            potentialAmount = potentialAmount.add(calculateTotalRewardToWithdraw(currentAccount));  //Normal Reward
        }

        return potentialAmount;
    }


    //--------------------------------------------------------------------
    //-------------------------- CLIENTS -----------------------------------
    //--------------------------------------------------------------------