// File: contracts/StMATIC.sol



// SPDX-FileCopyrightText: 2021 ShardLabs
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.7;

import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";

import "./interfaces/IValidatorShare.sol";
import "./interfaces/INodeOperatorRegistry.sol";
import "./interfaces/IStakeManager.sol";
import "./interfaces/IPoLidoNFT.sol";
import "./interfaces/IFxStateRootTunnel.sol";
import "./interfaces/IStMATIC.sol";

contract StMATIC is
    IStMATIC,
    ERC20Upgradeable,
    AccessControlUpgradeable,
    PausableUpgradeable
{
    event SubmitEvent(address indexed _from, uint256 indexed _amount);
    event RequestWithdrawEvent(address indexed _from, uint256 indexed _amount);
    event DistributeRewardsEvent(uint256 indexed _amount);
    event WithdrawTotalDelegatedEvent(
        address indexed _from,
        uint256 indexed _amount
    );
    event DelegateEvent(
        uint256 indexed _amountDelegated,
        uint256 indexed _remainder
    );
    event ClaimTokensEvent(
        address indexed _from,
        uint256 indexed _id,
        uint256 indexed _amountClaimed,
        uint256 _amountBurned
    );

    event ClaimTotalDelegatedEvent(
        address indexed _from,
        uint256 indexed _amountClaimed
    );

    using SafeERC20Upgradeable for IERC20Upgradeable;

    INodeOperatorRegistry public override nodeOperatorRegistry;
    FeeDistribution public override entityFees;
    IStakeManager public override stakeManager;
    IPoLidoNFT public override poLidoNFT;
    IFxStateRootTunnel public override fxStateRootTunnel;

    string public override version;
    address public override dao;
    address public override insurance;
    address public override token;
    uint256 public override lastWithdrawnValidatorId;
    uint256 public override totalBuffered;
    uint256 public override delegationLowerBound;
    uint256 public override rewardDistributionLowerBound;
    uint256 public override reservedFunds;
    uint256 public override submitThreshold;

    bool public override submitHandler;

    mapping(uint256 => RequestWithdraw) public override token2WithdrawRequest;

    bytes32 public constant override DAO = keccak256("DAO");

    RequestWithdraw[] public stMaticWithdrawRequest;

    /**
     * @param _nodeOperatorRegistry - Address of the node operator registry
     * @param _token - Address of MATIC token on Ethereum Mainnet
     * @param _dao - Address of the DAO
     * @param _insurance - Address of the insurance
     * @param _stakeManager - Address of the stake manager
     * @param _poLidoNFT - Address of the stMATIC NFT
     * @param _fxStateRootTunnel - Address of the FxStateRootTunnel
     */
    function initialize(
        address _nodeOperatorRegistry,
        address _token,
        address _dao,
        address _insurance,
        address _stakeManager,
        address _poLidoNFT,
        address _fxStateRootTunnel,
        uint256 _submitThreshold
    ) external override initializer {
        __AccessControl_init();
        __Pausable_init();
        __ERC20_init("Staked MATIC", "stMATIC");

        _setupRole(DEFAULT_ADMIN_ROLE, msg.sender);
        _setupRole(DAO, _dao);

        nodeOperatorRegistry = INodeOperatorRegistry(_nodeOperatorRegistry);
        stakeManager = IStakeManager(_stakeManager);
        poLidoNFT = IPoLidoNFT(_poLidoNFT);
        fxStateRootTunnel = IFxStateRootTunnel(_fxStateRootTunnel);
        dao = _dao;
        token = _token;
        insurance = _insurance;

        entityFees = FeeDistribution(25, 50, 25);
        submitThreshold = _submitThreshold;
        submitHandler = true;
    }

    /**
     * @dev Send funds to StMATIC contract and mints StMATIC to msg.sender
     * @notice Requires that msg.sender has approved _amount of MATIC to this contract
     * @param _amount - Amount of MATIC sent from msg.sender to this contract
     * @return Amount of StMATIC shares generated
     */
    function submit(uint256 _amount)
        external
        override
        whenNotPaused
        returns (uint256)
    {
        require(_amount > 0, "Invalid amount");

        if (submitHandler) {
            require(
                _amount + getTotalPooledMatic() <= submitThreshold,
                "Submit threshold reached"
            );
        }

        IERC20Upgradeable(token).safeTransferFrom(
            msg.sender,
            address(this),
            _amount
        );

        (
            uint256 amountToMint,
            uint256 totalShares,
            uint256 totalPooledMatic
        ) = convertMaticToStMatic(_amount);

        _mint(msg.sender, amountToMint);

        totalBuffered += _amount;

        fxStateRootTunnel.sendMessageToChild(
            abi.encode(totalShares + amountToMint, totalPooledMatic + _amount)
        );

        emit SubmitEvent(msg.sender, _amount);

        return amountToMint;
    }

    /**
     * @dev Stores users request to withdraw into a RequestWithdraw struct
     * @param _amount - Amount of StMATIC that is requested to withdraw
     */
    function requestWithdraw(uint256 _amount) external override whenNotPaused {
        require(_amount > 0, "Invalid amount");

        Operator.OperatorInfo[] memory operatorInfos = nodeOperatorRegistry
            .getOperatorInfos(false, true);

        uint256 operatorInfosLength = operatorInfos.length;

        uint256 tokenId;
        (
            uint256 totalAmount2WithdrawInMatic,
            uint256 totalShares,
            uint256 totalPooledMATIC
        ) = convertStMaticToMatic(_amount);
        uint256 currentAmount2WithdrawInMatic = totalAmount2WithdrawInMatic;

        uint256 totalDelegated = getTotalStakeAcrossAllValidators();

        uint256 minValidatorBalance = _getMinValidatorBalance(operatorInfos);

        uint256 allowedAmount2RequestFromValidators = 0;

        if (totalDelegated != 0) {
            require(
                (totalDelegated + totalBuffered) >=
                    currentAmount2WithdrawInMatic +
                        minValidatorBalance *
                        operatorInfosLength,
                "Too much to withdraw"
            );
            allowedAmount2RequestFromValidators =
                totalDelegated -
                minValidatorBalance *
                operatorInfosLength;
        } else {
            require(
                totalBuffered >= currentAmount2WithdrawInMatic,
                "Too much to withdraw"
            );
        }

        while (currentAmount2WithdrawInMatic != 0) {
            tokenId = poLidoNFT.mint(msg.sender);

            if (allowedAmount2RequestFromValidators != 0) {
                if (lastWithdrawnValidatorId > operatorInfosLength - 1) {
                    lastWithdrawnValidatorId = 0;
                }
                address validatorShare = operatorInfos[lastWithdrawnValidatorId]
                    .validatorShare;

                (uint256 validatorBalance, ) = IValidatorShare(validatorShare)
                    .getTotalStake(address(this));

                if (validatorBalance <= minValidatorBalance) {
                    lastWithdrawnValidatorId++;
                    continue;
                }

                uint256 allowedAmount2Withdraw = validatorBalance -
                    minValidatorBalance;

                uint256 amount2WithdrawFromValidator = (allowedAmount2Withdraw <=
                        currentAmount2WithdrawInMatic)
                        ? allowedAmount2Withdraw
                        : currentAmount2WithdrawInMatic;

                sellVoucher_new(
                    validatorShare,
                    amount2WithdrawFromValidator,
                    type(uint256).max
                );

                token2WithdrawRequest[tokenId] = RequestWithdraw(
                    0,
                    IValidatorShare(validatorShare).unbondNonces(address(this)),
                    stakeManager.epoch() + stakeManager.withdrawalDelay(),
                    validatorShare
                );

                allowedAmount2RequestFromValidators -= amount2WithdrawFromValidator;
                currentAmount2WithdrawInMatic -= amount2WithdrawFromValidator;
                lastWithdrawnValidatorId++;
            } else {
                token2WithdrawRequest[tokenId] = RequestWithdraw(
                    currentAmount2WithdrawInMatic,
                    0,
                    stakeManager.epoch() + stakeManager.withdrawalDelay(),
                    address(0)
                );

                reservedFunds += currentAmount2WithdrawInMatic;
                currentAmount2WithdrawInMatic = 0;
            }
        }

        _burn(msg.sender, _amount);

        fxStateRootTunnel.sendMessageToChild(
            abi.encode(
                totalShares - _amount,
                totalPooledMATIC - totalAmount2WithdrawInMatic
            )
        );

        emit RequestWithdrawEvent(msg.sender, _amount);
    }

    /**
     * @notice This will be included in the cron job
     * @dev Delegates tokens to validator share contract
     */
    function delegate() external override whenNotPaused {
        require(
            totalBuffered > delegationLowerBound + reservedFunds,
            "Amount to delegate lower than minimum"
        );
        Operator.OperatorInfo[] memory operatorInfos = nodeOperatorRegistry
            .getOperatorInfos(true, false);
        uint256 operatorInfosLength = operatorInfos.length;

        require(operatorInfosLength > 0, "No operator shares, cannot delegate");

        uint256 availableAmountToDelegate = totalBuffered - reservedFunds;
        uint256 maxDelegateLimitsSum;
        uint256 remainder;

        for (uint256 i = 0; i < operatorInfosLength; i++) {
            maxDelegateLimitsSum += operatorInfos[i].maxDelegateLimit;
        }

        require(maxDelegateLimitsSum > 0, "maxDelegateLimitsSum=0");

        uint256 totalToDelegatedAmount = maxDelegateLimitsSum <=
            availableAmountToDelegate
            ? maxDelegateLimitsSum
            : availableAmountToDelegate;

        IERC20Upgradeable(token).safeApprove(address(stakeManager), 0);

        IERC20Upgradeable(token).safeApprove(
            address(stakeManager),
            totalToDelegatedAmount
        );

        uint256 amountDelegated;

        for (uint256 i = 0; i < operatorInfosLength; i++) {
            uint256 amountToDelegatePerOperator = (operatorInfos[i]
                .maxDelegateLimit * totalToDelegatedAmount) /
                maxDelegateLimitsSum;

            buyVoucher(
                operatorInfos[i].validatorShare,
                amountToDelegatePerOperator,
                0
            );

            amountDelegated += amountToDelegatePerOperator;
        }

        remainder = availableAmountToDelegate - amountDelegated;
        totalBuffered = remainder + reservedFunds;

        emit DelegateEvent(amountDelegated, remainder);
    }

    /**
     * @dev Claims tokens from validator share and sends them to the
     * user if his request is in the userToWithdrawRequest
     * @param _tokenId - Id of the token that wants to be claimed
     */
    function claimTokens(uint256 _tokenId) external override whenNotPaused {
        require(poLidoNFT.isApprovedOrOwner(msg.sender, _tokenId), "Not owner");
        RequestWithdraw storage usersRequest = token2WithdrawRequest[_tokenId];

        require(
            stakeManager.epoch() >= usersRequest.requestEpoch,
            "Not able to claim yet"
        );

        poLidoNFT.burn(_tokenId);

        uint256 amountToClaim;

        if (usersRequest.validatorAddress != address(0)) {
            uint256 balanceBeforeClaim = IERC20Upgradeable(token).balanceOf(
                address(this)
            );

            unstakeClaimTokens_new(
                usersRequest.validatorAddress,
                usersRequest.validatorNonce
            );

            amountToClaim =
                IERC20Upgradeable(token).balanceOf(address(this)) -
                balanceBeforeClaim;
        } else {
            amountToClaim = usersRequest.amount2WithdrawFromStMATIC;

            reservedFunds -= amountToClaim;
            totalBuffered -= amountToClaim;
        }

        IERC20Upgradeable(token).safeTransfer(msg.sender, amountToClaim);

        emit ClaimTokensEvent(msg.sender, _tokenId, amountToClaim, 0);
    }

    /**
     * @dev Distributes rewards claimed from validator shares based on fees defined in entityFee
     */
    function distributeRewards() external override whenNotPaused {
        Operator.OperatorInfo[] memory operatorInfos = nodeOperatorRegistry
            .getOperatorInfos(true, false);

        uint256 operatorInfosLength = operatorInfos.length;

        for (uint256 i = 0; i < operatorInfosLength; i++) {
            IValidatorShare validatorShare = IValidatorShare(
                operatorInfos[i].validatorShare
            );
            uint256 stMaticReward = validatorShare.getLiquidRewards(
                address(this)
            );
            uint256 rewardThreshold = validatorShare.minAmount();
            if (stMaticReward >= rewardThreshold) {
                validatorShare.withdrawRewards();
            }
        }

        uint256 totalRewards = (
            (IERC20Upgradeable(token).balanceOf(address(this)) - totalBuffered)
        ) / 10;

        require(
            totalRewards > rewardDistributionLowerBound,
            "Amount to distribute lower than minimum"
        );

        uint256 balanceBeforeDistribution = IERC20Upgradeable(token).balanceOf(
            address(this)
        );

        uint256 daoRewards = (totalRewards * entityFees.dao) / 100;
        uint256 insuranceRewards = (totalRewards * entityFees.insurance) / 100;
        uint256 operatorsRewards = (totalRewards * entityFees.operators) / 100;
        uint256 operatorReward = operatorsRewards / operatorInfosLength;

        IERC20Upgradeable(token).safeTransfer(dao, daoRewards);
        IERC20Upgradeable(token).safeTransfer(insurance, insuranceRewards);

        for (uint256 i = 0; i < operatorInfosLength; i++) {
            IERC20Upgradeable(token).safeTransfer(
                operatorInfos[i].rewardAddress,
                operatorReward
            );
        }

        uint256 currentBalance = IERC20Upgradeable(token).balanceOf(
            address(this)
        );

        uint256 totalDistributed = balanceBeforeDistribution - currentBalance;

        // Add the remainder to totalBuffered
        totalBuffered = currentBalance;

        emit DistributeRewardsEvent(totalDistributed);
    }

    /**
     * @notice Only NodeOperatorRegistry can call this function
     * @dev Withdraws funds from unstaked validator
     * @param _validatorShare - Address of the validator share that will be withdrawn
     */
    function withdrawTotalDelegated(address _validatorShare) external override {
        require(
            msg.sender == address(nodeOperatorRegistry),
            "Not a node operator"
        );

        (uint256 stakedAmount, ) = getTotalStake(
            IValidatorShare(_validatorShare)
        );

        if (stakedAmount == 0) {
            return;
        }

        sellVoucher_new(_validatorShare, stakedAmount, type(uint256).max);

        stMaticWithdrawRequest.push(
            RequestWithdraw(
                uint256(0),
                IValidatorShare(_validatorShare).unbondNonces(address(this)),
                stakeManager.epoch() + stakeManager.withdrawalDelay(),
                _validatorShare
            )
        );

        fxStateRootTunnel.sendMessageToChild(
            abi.encode(totalSupply(), getTotalPooledMatic())
        );

        emit WithdrawTotalDelegatedEvent(_validatorShare, stakedAmount);
    }

    /**
     * @dev Claims tokens from validator share and sends them to the
     * StMATIC contract
     * @param _index - index the request.
     */
    function claimTotalDelegated2StMatic(uint256 _index)
        external
        override
        whenNotPaused
    {
        uint256 length = stMaticWithdrawRequest.length;
        require(_index < length, "invalid index");

        RequestWithdraw memory lidoRequests = stMaticWithdrawRequest[_index];

        require(
            stakeManager.epoch() >= lidoRequests.requestEpoch,
            "Not able to claim yet"
        );

        uint256 balanceBeforeClaim = IERC20Upgradeable(token).balanceOf(
            address(this)
        );

        unstakeClaimTokens_new(
            lidoRequests.validatorAddress,
            lidoRequests.validatorNonce
        );

        uint256 claimedAmount = IERC20Upgradeable(token).balanceOf(
            address(this)
        ) - balanceBeforeClaim;

        totalBuffered += claimedAmount;
        
        if (_index != length - 1 && length != 1) {
            stMaticWithdrawRequest[_index] = stMaticWithdrawRequest[length - 1];
        }
        stMaticWithdrawRequest.pop();

        fxStateRootTunnel.sendMessageToChild(
            abi.encode(totalSupply(), getTotalPooledMatic())
        );

        emit ClaimTotalDelegatedEvent(address(this), claimedAmount);
    }

    /**
     * @dev Flips the pause state
     */
    function togglePause() external override onlyRole(DEFAULT_ADMIN_ROLE) {
        paused() ? _unpause() : _pause();
    }

    ////////////////////////////////////////////////////////////
    /////                                                    ///
    /////             ***ValidatorShare API***               ///
    /////                                                    ///
    ////////////////////////////////////////////////////////////

    /**
     * @dev API for delegated buying vouchers from validatorShare
     * @param _validatorShare - Address of validatorShare contract
     * @param _amount - Amount of MATIC to use for buying vouchers
     * @param _minSharesToMint - Minimum of shares that is bought with _amount of MATIC
     * @return Actual amount of MATIC used to buy voucher, might differ from _amount because of _minSharesToMint
     */
    function buyVoucher(
        address _validatorShare,
        uint256 _amount,
        uint256 _minSharesToMint
    ) private returns (uint256) {
        uint256 amountSpent = IValidatorShare(_validatorShare).buyVoucher(
            _amount,
            _minSharesToMint
        );

        return amountSpent;
    }

    /**
     * @dev API for delegated restaking rewards to validatorShare
     * @param _validatorShare - Address of validatorShare contract
     */
    function restake(address _validatorShare) private {
        IValidatorShare(_validatorShare).restake();
    }

    /**
     * @dev API for delegated unstaking and claiming tokens from validatorShare
     * @param _validatorShare - Address of validatorShare contract
     * @param _unbondNonce - Unbond nonce
     */
    function unstakeClaimTokens_new(
        address _validatorShare,
        uint256 _unbondNonce
    ) private {
        IValidatorShare(_validatorShare).unstakeClaimTokens_new(_unbondNonce);
    }

    /**
     * @dev API for delegated selling vouchers from validatorShare
     * @param _validatorShare - Address of validatorShare contract
     * @param _claimAmount - Amount of MATIC to claim
     * @param _maximumSharesToBurn - Maximum amount of shares to burn
     */
    function sellVoucher_new(
        address _validatorShare,
        uint256 _claimAmount,
        uint256 _maximumSharesToBurn
    ) private {
        IValidatorShare(_validatorShare).sellVoucher_new(
            _claimAmount,
            _maximumSharesToBurn
        );
    }

    /**
     * @dev API for getting total stake of this contract from validatorShare
     * @param _validatorShare - Address of validatorShare contract
     * @return Total stake of this contract and MATIC -> share exchange rate
     */
    function getTotalStake(IValidatorShare _validatorShare)
        public
        view
        override
        returns (uint256, uint256)
    {
        return _validatorShare.getTotalStake(address(this));
    }

    /**
     * @dev API for liquid rewards of this contract from validatorShare
     * @param _validatorShare - Address of validatorShare contract
     * @return Liquid rewards of this contract
     */
    function getLiquidRewards(IValidatorShare _validatorShare)
        external
        view
        override
        returns (uint256)
    {
        return _validatorShare.getLiquidRewards(address(this));
    }

    ////////////////////////////////////////////////////////////
    /////                                                    ///
    /////            ***Helpers & Utilities***               ///
    /////                                                    ///
    ////////////////////////////////////////////////////////////
    /**
     * @dev Returns the stMaticWithdrawRequest list
     */
    function getTotalWithdrawRequest()
        public
        view
        returns (RequestWithdraw[] memory)
    {
        return stMaticWithdrawRequest;
    }

    /**
     * @dev Helper function for that returns total pooled MATIC
     * @return Total pooled MATIC
     */
    function getTotalStakeAcrossAllValidators()
        public
        view
        override
        returns (uint256)
    {
        uint256 totalStake;
        Operator.OperatorInfo[] memory operatorInfos = nodeOperatorRegistry
            .getOperatorInfos(false, true);

        uint256 operatorInfosLength = operatorInfos.length;
        for (uint256 i = 0; i < operatorInfosLength; i++) {
            (uint256 currValidatorShare, ) = getTotalStake(
                IValidatorShare(operatorInfos[i].validatorShare)
            );

            totalStake += currValidatorShare;
        }

        return totalStake;
    }

    /**
     * @dev Function that calculates total pooled Matic
     * @return Total pooled Matic
     */
    function getTotalPooledMatic() public view override returns (uint256) {
        uint256 totalStaked = getTotalStakeAcrossAllValidators();
        return
            totalStaked +
            totalBuffered +
            calculatePendingBufferedTokens() -
            reservedFunds;
    }

    /**
     * @dev Function that converts arbitrary stMATIC to Matic
     * @param _balance - Balance in stMATIC
     * @return Balance in Matic, totalShares and totalPooledMATIC
     */
    function convertStMaticToMatic(uint256 _balance)
        public
        view
        override
        returns (
            uint256,
            uint256,
            uint256
        )
    {
        uint256 totalShares = totalSupply();
        totalShares = totalShares == 0 ? 1 : totalShares;

        uint256 totalPooledMATIC = getTotalPooledMatic();
        totalPooledMATIC = totalPooledMATIC == 0 ? 1 : totalPooledMATIC;

        uint256 balanceInMATIC = (_balance * totalPooledMATIC) / totalShares;

        return (balanceInMATIC, totalShares, totalPooledMATIC);
    }

    /**
     * @dev Function that converts arbitrary Matic to stMATIC
     * @param _balance - Balance in Matic
     * @return Balance in stMATIC, totalShares and totalPooledMATIC
     */
    function convertMaticToStMatic(uint256 _balance)
        public
        view
        override
        returns (
            uint256,
            uint256,
            uint256
        )
    {
        uint256 totalShares = totalSupply();
        totalShares = totalShares == 0 ? 1 : totalShares;

        uint256 totalPooledMatic = getTotalPooledMatic();
        totalPooledMatic = totalPooledMatic == 0 ? 1 : totalPooledMatic;

        uint256 balanceInStMatic = (_balance * totalShares) / totalPooledMatic;

        return (balanceInStMatic, totalShares, totalPooledMatic);
    }

    /**
     * @dev Function that calculates minimal allowed validator balance (lower bound)
     * @return Minimal validator balance in MATIC
     */
    function getMinValidatorBalance() external view override returns (uint256) {
        Operator.OperatorInfo[] memory operatorInfos = nodeOperatorRegistry
            .getOperatorInfos(false, true);

        return _getMinValidatorBalance(operatorInfos);
    }

    function _getMinValidatorBalance(
        Operator.OperatorInfo[] memory operatorInfos
    ) private view returns (uint256) {
        uint256 operatorInfosLength = operatorInfos.length;
        uint256 minValidatorBalance = type(uint256).max;

        for (uint256 i = 0; i < operatorInfosLength; i++) {
            (uint256 validatorShare, ) = getTotalStake(
                IValidatorShare(operatorInfos[i].validatorShare)
            );
            // 10% of current validatorShare
            uint256 minValidatorBalanceCurrent = validatorShare / 10;

            if (
                minValidatorBalanceCurrent != 0 &&
                minValidatorBalanceCurrent < minValidatorBalance
            ) {
                minValidatorBalance = minValidatorBalanceCurrent;
            }
        }

        return minValidatorBalance;
    }

    ////////////////////////////////////////////////////////////
    /////                                                    ///
    /////                 ***Setters***                      ///
    /////                                                    ///
    ////////////////////////////////////////////////////////////

    /**
     * @dev Function that sets entity fees
     * @notice Callable only by dao
     * @param _daoFee - DAO fee in %
     * @param _operatorsFee - Operator fees in %
     * @param _insuranceFee - Insurance fee in %
     */
    function setFees(
        uint8 _daoFee,
        uint8 _operatorsFee,
        uint8 _insuranceFee
    ) external override onlyRole(DAO) {
        require(
            _daoFee + _operatorsFee + _insuranceFee == 100,
            "sum(fee)!=100"
        );
        entityFees.dao = _daoFee;
        entityFees.operators = _operatorsFee;
        entityFees.insurance = _insuranceFee;
    }

    /**
     * @dev Function that sets new dao address
     * @notice Callable only by dao
     * @param _address - New dao address
     */
    function setDaoAddress(address _address) external override onlyRole(DAO) {
        revokeRole(DAO, dao);
        dao = _address;
        _setupRole(DAO, dao);
    }

    /**
     * @dev Function that sets new insurance address
     * @notice Callable only by dao
     * @param _address - New insurance address
     */
    function setInsuranceAddress(address _address)
        external
        override
        onlyRole(DAO)
    {
        insurance = _address;
    }

    /**
     * @dev Function that sets new node operator address
     * @notice Only callable by dao
     * @param _address - New node operator address
     */
    function setNodeOperatorRegistryAddress(address _address)
        external
        override
        onlyRole(DAO)
    {
        nodeOperatorRegistry = INodeOperatorRegistry(_address);
    }

    /**
     * @dev Function that sets new lower bound for delegation
     * @notice Only callable by dao
     * @param _delegationLowerBound - New lower bound for delegation
     */
    function setDelegationLowerBound(uint256 _delegationLowerBound)
        external
        override
        onlyRole(DAO)
    {
        delegationLowerBound = _delegationLowerBound;
    }

    /**
     * @dev Function that sets new lower bound for rewards distribution
     * @notice Only callable by dao
     * @param _rewardDistributionLowerBound - New lower bound for rewards distribution
     */
    function setRewardDistributionLowerBound(
        uint256 _rewardDistributionLowerBound
    ) external override onlyRole(DAO) {
        rewardDistributionLowerBound = _rewardDistributionLowerBound;
    }

    /**
     * @dev Function that sets the poLidoNFT address
     * @param _poLidoNFT new poLidoNFT address
     */
    function setPoLidoNFT(address _poLidoNFT) external override onlyRole(DAO) {
        poLidoNFT = IPoLidoNFT(_poLidoNFT);
    }

    /**
     * @dev Function that sets the fxStateRootTunnel address
     * @param _fxStateRootTunnel address of fxStateRootTunnel
     */
    function setFxStateRootTunnel(address _fxStateRootTunnel)
        external
        override
        onlyRole(DAO)
    {
        fxStateRootTunnel = IFxStateRootTunnel(_fxStateRootTunnel);
    }

    /**
     * @dev Function that sets the submitThreshold
     * @param _submitThreshold new value for submit threshold
     */
    function setSubmitThreshold(uint256 _submitThreshold)
        external
        override
        onlyRole(DAO)
    {
        submitThreshold = _submitThreshold;
    }

    /**
     * @dev Function that sets the submitHandler value to its NOT value
     */
    function flipSubmitHandler() external override onlyRole(DAO) {
        submitHandler = !submitHandler;
    }

    /**
     * @dev Function that sets the new version
     * @param _version - New version that will be set
     */
    function setVersion(string calldata _version)
        external
        override
        onlyRole(DEFAULT_ADMIN_ROLE)
    {
        version = _version;
    }

    /**
     * @dev Function that retrieves the amount of matic that will be claimed from the NFT token
     * @param _tokenId - Id of the PolidoNFT
     */
    function getMaticFromTokenId(uint256 _tokenId)
        public
        view
        override
        returns (uint256)
    {
        return _getMaticFromRequestWithdraw(token2WithdrawRequest[_tokenId]);
    }

    function _getMaticFromRequestWithdraw(RequestWithdraw memory requestData)
        public
        view
        returns (uint256)
    {
        if (requestData.validatorAddress == address(0)) {
            return requestData.amount2WithdrawFromStMATIC;
        }

        IValidatorShare validatorShare = IValidatorShare(
            requestData.validatorAddress
        );
        uint256 validatorId = validatorShare.validatorId();
        
        // see here for more details about how to exchangeRatePrecision is calculated:
        // https://github.com/maticnetwork/contracts/blob/v0.3.0-backport/contracts/staking/validatorShare/ValidatorShare.sol#L313
        uint256 exchangeRatePrecision = validatorId < 8 ? 100 : 10**29;
        uint256 withdrawExchangeRate = validatorShare.withdrawExchangeRate();
        IValidatorShare.DelegatorUnbond memory unbond = validatorShare
            .unbonds_new(address(this), requestData.validatorNonce);

        return (withdrawExchangeRate * unbond.shares) / exchangeRatePrecision;
    }

    /**
     * @dev Function that calculates the total pending buffered tokens in LidoNFT contract.
     */
    function calculatePendingBufferedTokens()
        public
        view
        returns (uint256 pendingBufferedTokens)
    {
        RequestWithdraw[] memory requestData = stMaticWithdrawRequest;
        uint256 length = requestData.length;
        for (uint256 i = 0; i < length; i++) {
            pendingBufferedTokens += _getMaticFromRequestWithdraw(requestData[i]);
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20Upgradeable.sol";
import "./extensions/IERC20MetadataUpgradeable.sol";
import "../../utils/ContextUpgradeable.sol";
import "../../proxy/utils/Initializable.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20Upgradeable is Initializable, ContextUpgradeable, IERC20Upgradeable, IERC20MetadataUpgradeable {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    function __ERC20_init(string memory name_, string memory symbol_) internal onlyInitializing {
        __Context_init_unchained();
        __ERC20_init_unchained(name_, symbol_);
    }

    function __ERC20_init_unchained(string memory name_, string memory symbol_) internal onlyInitializing {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
    uint256[45] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol



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

pragma solidity ^0.8.0;

import "./IAccessControlUpgradeable.sol";
import "../utils/ContextUpgradeable.sol";
import "../utils/StringsUpgradeable.sol";
import "../utils/introspection/ERC165Upgradeable.sol";
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControlUpgradeable is Initializable, ContextUpgradeable, IAccessControlUpgradeable, ERC165Upgradeable {
    function __AccessControl_init() internal onlyInitializing {
        __Context_init_unchained();
        __ERC165_init_unchained();
        __AccessControl_init_unchained();
    }

    function __AccessControl_init_unchained() internal onlyInitializing {
    }
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role, _msgSender());
        _;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControlUpgradeable).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        StringsUpgradeable.toHexString(uint160(account), 20),
                        " is missing role ",
                        StringsUpgradeable.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
    uint256[49] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20Upgradeable {
    /**
     * @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);
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20Upgradeable.sol";
import "../../../utils/AddressUpgradeable.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20Upgradeable {
    using AddressUpgradeable for address;

    function safeTransfer(
        IERC20Upgradeable token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20Upgradeable 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(
        IERC20Upgradeable 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'
        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(
        IERC20Upgradeable token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20Upgradeable token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _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(IERC20Upgradeable 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
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: @openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol



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

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.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 PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @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.
     */
    function __Pausable_init() internal onlyInitializing {
        __Context_init_unchained();
        __Pausable_init_unchained();
    }

    function __Pausable_init_unchained() internal onlyInitializing {
        _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());
    }
    uint256[49] private __gap;
}

// File: contracts/interfaces/IValidatorShare.sol



// SPDX-FileCopyrightText: 2021 ShardLabs
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.7;

interface IValidatorShare {
    struct DelegatorUnbond {
        uint256 shares;
        uint256 withdrawEpoch;
    }

    function unbondNonces(address _address) external view returns (uint256);

    function activeAmount() external view returns (uint256);

    function validatorId() external view returns (uint256);

    function withdrawExchangeRate() external view returns (uint256);

    function withdrawRewards() external;

    function unstakeClaimTokens() external;

    function minAmount() external view returns (uint256);

    function getLiquidRewards(address user) external view returns (uint256);

    function delegation() external view returns (bool);

    function updateDelegation(bool _delegation) external;

    function buyVoucher(uint256 _amount, uint256 _minSharesToMint)
        external
        returns (uint256);

    function sellVoucher_new(uint256 claimAmount, uint256 maximumSharesToBurn)
        external;

    function unstakeClaimTokens_new(uint256 unbondNonce) external;

    function unbonds_new(address _address, uint256 _unbondNonce)
        external
        view
        returns (DelegatorUnbond memory);

    function getTotalStake(address user)
        external
        view
        returns (uint256, uint256);

    function owner() external view returns (address);

    function restake() external returns (uint256, uint256);

    function unlock() external;

    function lock() external;

    function drain(
        address token,
        address payable destination,
        uint256 amount
    ) external;

    function slash(uint256 _amount) external;

    function migrateOut(address user, uint256 amount) external;

    function migrateIn(address user, uint256 amount) external;
}

// File: contracts/interfaces/INodeOperatorRegistry.sol



// SPDX-FileCopyrightText: 2021 ShardLabs
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.7;

import "../lib/Operator.sol";

/// @title INodeOperatorRegistry
/// @author 2021 ShardLabs
/// @notice Node operator registry interface
interface INodeOperatorRegistry {
    /// @notice Allows to add a new node operator to the system.
    /// @param _name the node operator name.
    /// @param _rewardAddress public address used for ACL and receive rewards.
    /// @param _signerPubkey public key used on heimdall len 64 bytes.
    function addOperator(
        string memory _name,
        address _rewardAddress,
        bytes memory _signerPubkey
    ) external;

    /// @notice Allows to stop a node operator.
    /// @param _operatorId node operator id.
    function stopOperator(uint256 _operatorId) external;

    /// @notice Allows to remove a node operator from the system.
    /// @param _operatorId node operator id.
    function removeOperator(uint256 _operatorId) external;

    /// @notice Allows a staked validator to join the system.
    function joinOperator() external;

    /// @notice Allows to stake an operator on the Polygon stakeManager.
    /// This function calls Polygon transferFrom so the totalAmount(_amount + _heimdallFee)
    /// has to be approved first.
    /// @param _amount amount to stake.
    /// @param _heimdallFee heimdallFee to stake.
    function stake(uint256 _amount, uint256 _heimdallFee) external;

    /// @notice Restake Matics for a validator on polygon stake manager.
    /// @param _amount amount to stake.
    /// @param _restakeRewards restake rewards.
    function restake(uint256 _amount, bool _restakeRewards) external;

    /// @notice Allows the operator's owner to migrate the NFT. This can be done only
    /// if the DAO stopped the operator.
    function migrate() external;

    /// @notice Allows to unstake an operator from the stakeManager. After the withdraw_delay
    /// the operator owner can call claimStake func to withdraw the staked tokens.
    function unstake() external;

    /// @notice Allows to topup heimdall fees on polygon stakeManager.
    /// @param _heimdallFee amount to topup.
    function topUpForFee(uint256 _heimdallFee) external;

    /// @notice Allows to claim staked tokens on the stake Manager after the end of the
    /// withdraw delay
    function unstakeClaim() external;

    /// @notice Allows an owner to withdraw rewards from the stakeManager.
    function withdrawRewards() external;

    /// @notice Allows to update the signer pubkey
    /// @param _signerPubkey update signer public key
    function updateSigner(bytes memory _signerPubkey) external;

    /// @notice Allows to claim the heimdall fees staked by the owner of the operator
    /// @param _accumFeeAmount accumulated fees amount
    /// @param _index index
    /// @param _proof proof
    function claimFee(
        uint256 _accumFeeAmount,
        uint256 _index,
        bytes memory _proof
    ) external;

    /// @notice Allows to unjail a validator and switch from UNSTAKE status to STAKED
    function unjail() external;

    /// @notice Allows an operator's owner to set the operator name.
    function setOperatorName(string memory _name) external;

    /// @notice Allows an operator's owner to set the operator rewardAddress.
    function setOperatorRewardAddress(address _rewardAddress) external;

    /// @notice Allows the DAO to set _defaultMaxDelegateLimit.
    function setDefaultMaxDelegateLimit(uint256 _defaultMaxDelegateLimit)
        external;

    /// @notice Allows the DAO to set _maxDelegateLimit for an operator.
    function setMaxDelegateLimit(uint256 _operatorId, uint256 _maxDelegateLimit)
        external;

    /// @notice Allows the DAO to set _commissionRate.
    function setCommissionRate(uint256 _commissionRate) external;

    /// @notice Allows the DAO to set _commissionRate for an operator.
    /// @param _operatorId id of the operator
    /// @param _newCommissionRate new commission rate
    function updateOperatorCommissionRate(
        uint256 _operatorId,
        uint256 _newCommissionRate
    ) external;

    /// @notice Allows the DAO to set _minAmountStake and _minHeimdallFees.
    function setStakeAmountAndFees(
        uint256 _minAmountStake,
        uint256 _minHeimdallFees
    ) external;

    /// @notice Allows to pause/unpause the node operator contract.
    function togglePause() external;

    /// @notice Allows the DAO to enable/disable restake.
    function setRestake(bool _restake) external;

    /// @notice Allows the DAO to set stMATIC contract.
    function setStMATIC(address _stMATIC) external;

    /// @notice Allows the DAO to set validator factory contract.
    function setValidatorFactory(address _validatorFactory) external;

    /// @notice Allows the DAO to set stake manager contract.
    function setStakeManager(address _stakeManager) external;

    /// @notice Allows to set contract version.
    function setVersion(string memory _version) external;

    /// @notice Get the stMATIC contract addresses
    function getContracts()
        external
        view
        returns (
            address _validatorFactory,
            address _stakeManager,
            address _polygonERC20,
            address _stMATIC
        );

    /// @notice Allows to get stats.
    function getState()
        external
        view
        returns (
            uint256 _totalNodeOperator,
            uint256 _totalInactiveNodeOperator,
            uint256 _totalActiveNodeOperator,
            uint256 _totalStoppedNodeOperator,
            uint256 _totalUnstakedNodeOperator,
            uint256 _totalClaimedNodeOperator,
            uint256 _totalExitNodeOperator,
            uint256 _totalSlashedNodeOperator,
            uint256 _totalEjectedNodeOperator
        );

    /// @notice Allows to get a list of operatorInfo.
    function getOperatorInfos(bool _delegation, bool _allActive)
        external
        view
        returns (Operator.OperatorInfo[] memory);


    /// @notice Allows to get all the operator ids.
    function getOperatorIds() external view returns (uint256[] memory);
}

// File: contracts/interfaces/IStakeManager.sol



// SPDX-FileCopyrightText: 2021 ShardLabs
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.7;

/// @title polygon stake manager interface.
/// @author 2021 ShardLabs
/// @notice User to interact with the polygon stake manager.
interface IStakeManager {
    /// @notice Stake a validator on polygon stake manager.
    /// @param user user that own the validator in our case the validator contract.
    /// @param amount amount to stake.
    /// @param heimdallFee heimdall fees.
    /// @param acceptDelegation accept delegation.
    /// @param signerPubkey signer publickey used in heimdall node.
    function stakeFor(
        address user,
        uint256 amount,
        uint256 heimdallFee,
        bool acceptDelegation,
        bytes memory signerPubkey
    ) external;

    /// @notice Restake Matics for a validator on polygon stake manager.
    /// @param validatorId validator id.
    /// @param amount amount to stake.
    /// @param stakeRewards restake rewards.
    function restake(
        uint256 validatorId,
        uint256 amount,
        bool stakeRewards
    ) external;

    /// @notice Request unstake a validator.
    /// @param validatorId validator id.
    function unstake(uint256 validatorId) external;

    /// @notice Increase the heimdall fees.
    /// @param user user that own the validator in our case the validator contract.
    /// @param heimdallFee heimdall fees.
    function topUpForFee(address user, uint256 heimdallFee) external;

    /// @notice Get the validator id using the user address.
    /// @param user user that own the validator in our case the validator contract.
    /// @return return the validator id
    function getValidatorId(address user) external view returns (uint256);

    /// @notice get the validator contract used for delegation.
    /// @param validatorId validator id.
    /// @return return the address of the validator contract.
    function getValidatorContract(uint256 validatorId)
        external
        view
        returns (address);

    /// @notice Withdraw accumulated rewards
    /// @param validatorId validator id.
    function withdrawRewards(uint256 validatorId) external;

    /// @notice Get validator total staked.
    /// @param validatorId validator id.
    function validatorStake(uint256 validatorId)
        external
        view
        returns (uint256);

    /// @notice Allows to unstake the staked tokens on the stakeManager.
    /// @param validatorId validator id.
    function unstakeClaim(uint256 validatorId) external;

    /// @notice Allows to update the signer pubkey
    /// @param _validatorId validator id
    /// @param _signerPubkey update signer public key
    function updateSigner(uint256 _validatorId, bytes memory _signerPubkey)
        external;

    /// @notice Allows to claim the heimdall fees.
    /// @param _accumFeeAmount accumulated fees amount
    /// @param _index index
    /// @param _proof proof
    function claimFee(
        uint256 _accumFeeAmount,
        uint256 _index,
        bytes memory _proof
    ) external;

    /// @notice Allows to update the commision rate of a validator
    /// @param _validatorId operator id
    /// @param _newCommissionRate commission rate
    function updateCommissionRate(
        uint256 _validatorId,
        uint256 _newCommissionRate
    ) external;

    /// @notice Allows to unjail a validator.
    /// @param _validatorId id of the validator that is to be unjailed
    function unjail(uint256 _validatorId) external;

    /// @notice Returns a withdrawal delay.
    function withdrawalDelay() external view returns (uint256);

    /// @notice Transfers amount from delegator
    function delegationDeposit(
        uint256 validatorId,
        uint256 amount,
        address delegator
    ) external returns (bool);

    function epoch() external view returns (uint256);

    enum Status {
        Inactive,
        Active,
        Locked,
        Unstaked
    }

    struct Validator {
        uint256 amount;
        uint256 reward;
        uint256 activationEpoch;
        uint256 deactivationEpoch;
        uint256 jailTime;
        address signer;
        address contractAddress;
        Status status;
        uint256 commissionRate;
        uint256 lastCommissionUpdate;
        uint256 delegatorsReward;
        uint256 delegatedAmount;
        uint256 initialRewardPerStake;
    }

    function validators(uint256 _index)
        external
        view
        returns (Validator memory);

    /// @notice Returns the address of the nft contract
    function NFTContract() external view returns (address);

    /// @notice Returns the validator accumulated rewards on stake manager.
    function validatorReward(uint256 validatorId)
        external
        view
        returns (uint256);
}

// File: contracts/interfaces/IPoLidoNFT.sol



// SPDX-FileCopyrightText: 2021 ShardLabs
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.7;

import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";

/// @title PoLidoNFT interface.
/// @author 2021 ShardLabs
interface IPoLidoNFT is IERC721Upgradeable {
    function mint(address _to) external returns (uint256);

    function burn(uint256 _tokenId) external;

    function isApprovedOrOwner(address _spender, uint256 _tokenId)
        external
        view
        returns (bool);

    function setStMATIC(address _stMATIC) external;
    function getOwnedTokens(address _address) external view returns (uint256[] memory);
}

// File: contracts/interfaces/IFxStateRootTunnel.sol



// SPDX-FileCopyrightText: 2021 ShardLabs
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.7;

interface IFxStateRootTunnel {
    function latestData() external view returns (bytes memory);

    function setFxChildTunnel(address _fxChildTunnel) external;

    function sendMessageToChild(bytes memory message) external;

    function setStMATIC(address _stMATIC) external;
}

// File: contracts/interfaces/IStMATIC.sol



// SPDX-FileCopyrightText: 2021 ShardLabs
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.7;

import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";

import "./IValidatorShare.sol";
import "./INodeOperatorRegistry.sol";
import "./INodeOperatorRegistry.sol";
import "./IStakeManager.sol";
import "./IPoLidoNFT.sol";
import "./IFxStateRootTunnel.sol";

/// @title StMATIC interface.
/// @author 2021 ShardLabs
interface IStMATIC is IERC20Upgradeable {
    struct RequestWithdraw {
        uint256 amount2WithdrawFromStMATIC;
        uint256 validatorNonce;
        uint256 requestEpoch;
        address validatorAddress;
    }

    struct FeeDistribution {
        uint8 dao;
        uint8 operators;
        uint8 insurance;
    }

    function withdrawTotalDelegated(address _validatorShare) external;

    function nodeOperatorRegistry() external returns (INodeOperatorRegistry);

    function entityFees()
        external
        returns (
            uint8,
            uint8,
            uint8
        );

    function getMaticFromTokenId(uint256 _tokenId)
        external
        view
        returns (uint256);

    function stakeManager() external view returns (IStakeManager);

    function poLidoNFT() external view returns (IPoLidoNFT);

    function fxStateRootTunnel() external view returns (IFxStateRootTunnel);

    function version() external view returns (string memory);

    function dao() external view returns (address);

    function insurance() external view returns (address);

    function token() external view returns (address);

    function lastWithdrawnValidatorId() external view returns (uint256);

    function totalBuffered() external view returns (uint256);

    function delegationLowerBound() external view returns (uint256);

    function rewardDistributionLowerBound() external view returns (uint256);

    function reservedFunds() external view returns (uint256);

    function submitThreshold() external view returns (uint256);

    function submitHandler() external view returns (bool);

    function getMinValidatorBalance() external view returns (uint256);

    function token2WithdrawRequest(uint256 _requestId)
        external
        view
        returns (
            uint256,
            uint256,
            uint256,
            address
        );

    function DAO() external view returns (bytes32);

    function initialize(
        address _nodeOperatorRegistry,
        address _token,
        address _dao,
        address _insurance,
        address _stakeManager,
        address _poLidoNFT,
        address _fxStateRootTunnel,
        uint256 _submitThreshold
    ) external;

    function submit(uint256 _amount) external returns (uint256);

    function requestWithdraw(uint256 _amount) external;

    function delegate() external;

    function claimTokens(uint256 _tokenId) external;

    function distributeRewards() external;

    function claimTotalDelegated2StMatic(uint256 _index) external;

    function togglePause() external;

    function getTotalStake(IValidatorShare _validatorShare)
        external
        view
        returns (uint256, uint256);

    function getLiquidRewards(IValidatorShare _validatorShare)
        external
        view
        returns (uint256);

    function getTotalStakeAcrossAllValidators() external view returns (uint256);

    function getTotalPooledMatic() external view returns (uint256);

    function convertStMaticToMatic(uint256 _balance)
        external
        view
        returns (
            uint256,
            uint256,
            uint256
        );

    function convertMaticToStMatic(uint256 _balance)
        external
        view
        returns (
            uint256,
            uint256,
            uint256
        );

    function setFees(
        uint8 _daoFee,
        uint8 _operatorsFee,
        uint8 _insuranceFee
    ) external;

    function setDaoAddress(address _address) external;

    function setInsuranceAddress(address _address) external;

    function setNodeOperatorRegistryAddress(address _address) external;

    function setDelegationLowerBound(uint256 _delegationLowerBound) external;

    function setRewardDistributionLowerBound(
        uint256 _rewardDistributionLowerBound
    ) external;

    function setPoLidoNFT(address _poLidoNFT) external;

    function setFxStateRootTunnel(address _fxStateRootTunnel) external;

    function setSubmitThreshold(uint256 _submitThreshold) external;

    function flipSubmitHandler() external;

    function setVersion(string calldata _version) external;
}

// File: @openzeppelin/contracts-upgradeable/token/ERC20/extensions/IERC20MetadataUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20Upgradeable.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20MetadataUpgradeable is IERC20Upgradeable {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

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

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

// File: @openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol



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

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @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 ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
        __Context_init_unchained();
    }

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

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol



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

pragma solidity ^0.8.0;

import "../../utils/AddressUpgradeable.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
 * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() initializer {}
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;

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

    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        // If the contract is initializing we ignore whether _initialized is set in order to support multiple
        // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
        // contract may have been reentered.
        require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");

        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} modifier, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}

// File: @openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol



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

pragma solidity ^0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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 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: @openzeppelin/contracts-upgradeable/access/IAccessControlUpgradeable.sol



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

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControlUpgradeable {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

// File: @openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol



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

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library StringsUpgradeable {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}

// File: @openzeppelin/contracts-upgradeable/utils/introspection/ERC165Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165Upgradeable.sol";
import "../../proxy/utils/Initializable.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
    function __ERC165_init() internal onlyInitializing {
        __ERC165_init_unchained();
    }

    function __ERC165_init_unchained() internal onlyInitializing {
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165Upgradeable).interfaceId;
    }
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/utils/introspection/IERC165Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165Upgradeable {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: contracts/lib/Operator.sol



// SPDX-FileCopyrightText: 2021 ShardLabs
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.7;

library Operator {
    struct OperatorInfo {
        uint256 operatorId;
        address validatorShare;
        uint256 maxDelegateLimit;
        address rewardAddress;
    }
}

// File: @openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165Upgradeable.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721Upgradeable is IERC165Upgradeable {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;
}