// File: contracts/MaticX.sol



// 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/IValidatorRegistry.sol";
import "./interfaces/IStakeManager.sol";
import "./interfaces/IMaticX.sol";
import "./interfaces/IFxStateRootTunnel.sol";

contract MaticX is
	IMaticX,
	ERC20Upgradeable,
	AccessControlUpgradeable,
	PausableUpgradeable
{
	using SafeERC20Upgradeable for IERC20Upgradeable;

	address private validatorRegistry;
	address private stakeManager;
	address private polygonERC20;

	address public override treasury;
	string public override version;
	uint8 public override feePercent;

	bytes32 public constant INSTANT_POOL_OWNER = keccak256("IPO");
	address public override instantPoolOwner;
	uint256 public override instantPoolMatic;
	uint256 public override instantPoolMaticX;

	/// @notice Mapping of all user ids with withdraw requests.
	mapping(address => WithdrawalRequest[]) private userWithdrawalRequests;

	bytes32 public constant PREDICATE_ROLE = keccak256("PREDICATE_ROLE");

	address public override fxStateRootTunnel;

	/**
	 * @param _validatorRegistry - Address of the validator registry
	 * @param _stakeManager - Address of the stake manager
	 * @param _polygonERC20 - Address of matic token on Ethereum
	 * @param _manager - Address of the manager
	 * @param _instantPoolOwner - Address of the instant pool owner
	 * @param _treasury - Address of the treasury
	 */
	function initialize(
		address _validatorRegistry,
		address _stakeManager,
		address _polygonERC20,
		address _manager,
		address _instantPoolOwner,
		address _treasury
	) external override initializer {
		__AccessControl_init();
		__Pausable_init();
		__ERC20_init("Liquid Staking Matic", "MaticX");

		_setupRole(DEFAULT_ADMIN_ROLE, _manager);
		_setupRole(INSTANT_POOL_OWNER, _instantPoolOwner);
		instantPoolOwner = _instantPoolOwner;

		validatorRegistry = _validatorRegistry;
		stakeManager = _stakeManager;
		treasury = _treasury;
		polygonERC20 = _polygonERC20;

		feePercent = 5;

		IERC20Upgradeable(polygonERC20).safeApprove(
			stakeManager,
			type(uint256).max
		);
	}

	////////////////////////////////////////////////////////////
	/////                                                    ///
	/////             ***Instant Pool Interactions***        ///
	/////                                                    ///
	////////////////////////////////////////////////////////////

	// Uses instantPoolOwner funds.
	function provideInstantPoolMatic(uint256 _amount)
		external
		override
		whenNotPaused
		onlyRole(INSTANT_POOL_OWNER)
	{
		require(_amount > 0, "Invalid amount");
		IERC20Upgradeable(polygonERC20).safeTransferFrom(
			msg.sender,
			address(this),
			_amount
		);

		instantPoolMatic += _amount;
	}

	function provideInstantPoolMaticX(uint256 _amount)
		external
		override
		whenNotPaused
		onlyRole(INSTANT_POOL_OWNER)
	{
		require(_amount > 0, "Invalid amount");
		IERC20Upgradeable(address(this)).safeTransferFrom(
			msg.sender,
			address(this),
			_amount
		);

		instantPoolMaticX += _amount;
	}

	function withdrawInstantPoolMaticX(uint256 _amount)
		external
		override
		whenNotPaused
		onlyRole(INSTANT_POOL_OWNER)
	{
		require(
			instantPoolMaticX >= _amount,
			"Withdraw amount cannot exceed maticX in instant pool"
		);

		instantPoolMaticX -= _amount;
		IERC20Upgradeable(address(this)).safeTransfer(
			instantPoolOwner,
			_amount
		);
	}

	function withdrawInstantPoolMatic(uint256 _amount)
		external
		override
		whenNotPaused
		onlyRole(INSTANT_POOL_OWNER)
	{
		require(
			instantPoolMatic >= _amount,
			"Withdraw amount cannot exceed matic in instant pool"
		);

		instantPoolMatic -= _amount;
		IERC20Upgradeable(polygonERC20).safeTransfer(instantPoolOwner, _amount);
	}

	// Uses instantPoolMatic funds
	function mintMaticXToInstantPool()
		external
		override
		whenNotPaused
		onlyRole(INSTANT_POOL_OWNER)
	{
		require(instantPoolMatic > 0, "Matic amount cannot be 0");

		uint256 maticxMinted = helper_delegate_to_mint(
			address(this),
			instantPoolMatic
		);
		instantPoolMaticX += maticxMinted;
		instantPoolMatic = 0;
	}

	function swapMaticForMaticXViaInstantPool(uint256 _amount)
		external
		override
		whenNotPaused
	{
		require(_amount > 0, "Invalid amount");
		IERC20Upgradeable(polygonERC20).safeTransferFrom(
			msg.sender,
			address(this),
			_amount
		);

		(uint256 amountToMint, , ) = convertMaticToMaticX(_amount);
		require(
			instantPoolMaticX >= amountToMint,
			"Not enough maticX to instant swap"
		);

		IERC20Upgradeable(address(this)).safeTransfer(msg.sender, amountToMint);
		instantPoolMatic += _amount;
		instantPoolMaticX -= amountToMint;
	}

	////////////////////////////////////////////////////////////
	/////                                                    ///
	/////             ***Staking Contract Interactions***    ///
	/////                                                    ///
	////////////////////////////////////////////////////////////

	/**
	 * @dev Send funds to MaticX contract and mints MaticX 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 MaticX shares generated
	 */
	function submit(uint256 _amount)
		external
		override
		whenNotPaused
		returns (uint256)
	{
		require(_amount > 0, "Invalid amount");
		IERC20Upgradeable(polygonERC20).safeTransferFrom(
			msg.sender,
			address(this),
			_amount
		);

		return helper_delegate_to_mint(msg.sender, _amount);
	}

	/**
	 * @dev Stores user's request to withdraw into WithdrawalRequest struct
	 * @param _amount - Amount of maticX that is requested to withdraw
	 */
	function requestWithdraw(uint256 _amount) external override whenNotPaused {
		require(_amount > 0, "Invalid amount");

		(
			uint256 totalAmount2WithdrawInMatic,
			uint256 totalShares,
			uint256 totalPooledMatic
		) = convertMaticXToMatic(_amount);

		_burn(msg.sender, _amount);

		uint256 leftAmount2WithdrawInMatic = totalAmount2WithdrawInMatic;
		uint256 totalDelegated = getTotalStakeAcrossAllValidators();

		require(
			totalDelegated >= totalAmount2WithdrawInMatic,
			"Too much to withdraw"
		);

		uint256[] memory validators = IValidatorRegistry(validatorRegistry)
			.getValidators();
		uint256 preferredValidatorId = IValidatorRegistry(validatorRegistry)
			.preferredWithdrawalValidatorId();
		uint256 currentIdx = 0;
		for (; currentIdx < validators.length; ++currentIdx) {
			if (preferredValidatorId == validators[currentIdx]) break;
		}

		while (leftAmount2WithdrawInMatic > 0) {
			uint256 validatorId = validators[currentIdx];

			address validatorShare = IStakeManager(stakeManager)
				.getValidatorContract(validatorId);
			(uint256 validatorBalance, ) = getTotalStake(
				IValidatorShare(validatorShare)
			);

			uint256 amount2WithdrawFromValidator = (validatorBalance <=
				leftAmount2WithdrawInMatic)
				? validatorBalance
				: leftAmount2WithdrawInMatic;

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

			userWithdrawalRequests[msg.sender].push(
				WithdrawalRequest(
					IValidatorShare(validatorShare).unbondNonces(address(this)),
					IStakeManager(stakeManager).epoch() +
						IStakeManager(stakeManager).withdrawalDelay(),
					validatorShare
				)
			);

			leftAmount2WithdrawInMatic -= amount2WithdrawFromValidator;
			currentIdx = currentIdx + 1 < validators.length
				? currentIdx + 1
				: 0;
		}

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

		emit RequestWithdraw(msg.sender, _amount, totalAmount2WithdrawInMatic);
	}

	/**
	 * @dev Claims tokens from validator share and sends them to the
	 * address if the request is in the userWithdrawalRequests
	 * @param _idx - User withdrawal request array index
	 */
	function claimWithdrawal(uint256 _idx) external override whenNotPaused {
		_claimWithdrawal(msg.sender, _idx);
	}

	function withdrawRewards(uint256 _validatorId)
		public
		override
		whenNotPaused
		returns (uint256)
	{
		address validatorShare = IStakeManager(stakeManager)
			.getValidatorContract(_validatorId);

		uint256 balanceBeforeRewards = IERC20Upgradeable(polygonERC20)
			.balanceOf(address(this));
		IValidatorShare(validatorShare).withdrawRewards();
		uint256 rewards = IERC20Upgradeable(polygonERC20).balanceOf(
			address(this)
		) - balanceBeforeRewards;

		emit WithdrawRewards(_validatorId, rewards);
		return rewards;
	}

	function stakeRewardsAndDistributeFees(uint256 _validatorId)
		external
		override
		whenNotPaused
		onlyRole(DEFAULT_ADMIN_ROLE)
	{
		require(
			IValidatorRegistry(validatorRegistry).validatorIdExists(
				_validatorId
			),
			"Doesn't exist in validator registry"
		);

		address validatorShare = IStakeManager(stakeManager)
			.getValidatorContract(_validatorId);

		uint256 rewards = IERC20Upgradeable(polygonERC20).balanceOf(
			address(this)
		) - instantPoolMatic;

		require(rewards > 0, "Reward is zero");

		uint256 treasuryFees = (rewards * feePercent) / 100;

		if (treasuryFees > 0) {
			IERC20Upgradeable(polygonERC20).safeTransfer(
				treasury,
				treasuryFees
			);
			emit DistributeFees(treasury, treasuryFees);
		}

		uint256 amountStaked = rewards - treasuryFees;
		IValidatorShare(validatorShare).buyVoucher(amountStaked, 0);

		uint256 totalShares = totalSupply();
		uint256 totalPooledMatic = getTotalPooledMatic();

		IFxStateRootTunnel(fxStateRootTunnel).sendMessageToChild(
			abi.encode(totalShares, totalPooledMatic)
		);

		emit StakeRewards(_validatorId, amountStaked);
	}

	/**
	 * @dev Migrate the staked tokens to another validaor
	 */
	function migrateDelegation(
		uint256 _fromValidatorId,
		uint256 _toValidatorId,
		uint256 _amount
	) external override whenNotPaused onlyRole(DEFAULT_ADMIN_ROLE) {
		require(
			IValidatorRegistry(validatorRegistry).validatorIdExists(
				_fromValidatorId
			),
			"From validator id does not exist in our registry"
		);
		require(
			IValidatorRegistry(validatorRegistry).validatorIdExists(
				_toValidatorId
			),
			"To validator id does not exist in our registry"
		);

		IStakeManager(stakeManager).migrateDelegation(
			_fromValidatorId,
			_toValidatorId,
			_amount
		);

		emit MigrateDelegation(_fromValidatorId, _toValidatorId, _amount);
	}

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

	/**
	 * @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));
	}

	////////////////////////////////////////////////////////////
	/////                                                    ///
	/////            ***Helpers & Utilities***               ///
	/////                                                    ///
	////////////////////////////////////////////////////////////

	function helper_delegate_to_mint(address deposit_sender, uint256 _amount)
		internal
		whenNotPaused
		returns (uint256)
	{
		(
			uint256 amountToMint,
			uint256 totalShares,
			uint256 totalPooledMatic
		) = convertMaticToMaticX(_amount);

		_mint(deposit_sender, amountToMint);
		emit Submit(deposit_sender, _amount);

		uint256 preferredValidatorId = IValidatorRegistry(validatorRegistry)
			.preferredDepositValidatorId();
		address validatorShare = IStakeManager(stakeManager)
			.getValidatorContract(preferredValidatorId);
		IValidatorShare(validatorShare).buyVoucher(_amount, 0);

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

		emit Delegate(preferredValidatorId, _amount);
		return amountToMint;
	}

	/**
	 * @dev Claims tokens from validator share and sends them to the
	 * address if the request is in the userWithdrawalRequests
	 * @param _to - Address of the withdrawal request owner
	 * @param _idx - User withdrawal request array index
	 */
	function _claimWithdrawal(address _to, uint256 _idx)
		internal
		returns (uint256)
	{
		uint256 amountToClaim = 0;
		uint256 balanceBeforeClaim = IERC20Upgradeable(polygonERC20).balanceOf(
			address(this)
		);
		WithdrawalRequest[] storage userRequests = userWithdrawalRequests[_to];
		WithdrawalRequest memory userRequest = userRequests[_idx];
		require(
			IStakeManager(stakeManager).epoch() >= userRequest.requestEpoch,
			"Not able to claim yet"
		);

		IValidatorShare(userRequest.validatorAddress).unstakeClaimTokens_new(
			userRequest.validatorNonce
		);

		// swap with the last item and pop it.
		userRequests[_idx] = userRequests[userRequests.length - 1];
		userRequests.pop();

		amountToClaim =
			IERC20Upgradeable(polygonERC20).balanceOf(address(this)) -
			balanceBeforeClaim;

		IERC20Upgradeable(polygonERC20).safeTransfer(_to, amountToClaim);

		emit ClaimWithdrawal(_to, _idx, amountToClaim);
		return amountToClaim;
	}

	/**
	 * @dev Function that converts arbitrary maticX to Matic
	 * @param _balance - Balance in maticX
	 * @return Balance in Matic, totalShares and totalPooledMATIC
	 */
	function convertMaticXToMatic(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 maticX
	 * @param _balance - Balance in Matic
	 * @return Balance in maticX, totalShares and totalPooledMATIC
	 */
	function convertMaticToMaticX(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 balanceInMaticX = (_balance * totalShares) / totalPooledMatic;

		return (balanceInMaticX, totalShares, totalPooledMatic);
	}

	// TODO: Add logic and enable it in V2
	function mint(address _user, uint256 _amount)
		external
		override
		whenNotPaused
		onlyRole(PREDICATE_ROLE)
	{
		emit MintFromPolygon(_user, _amount);
	}

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

	/**
	 * @dev Function that sets fee percent
	 * @notice Callable only by manager
	 * @param _feePercent - Fee percent (10 = 10%)
	 */
	function setFeePercent(uint8 _feePercent)
		external
		override
		onlyRole(DEFAULT_ADMIN_ROLE)
	{
		require(_feePercent <= 100, "_feePercent must not exceed 100");

		feePercent = _feePercent;

		emit SetFeePercent(_feePercent);
	}

	function setInstantPoolOwner(address _address)
		external
		override
		onlyRole(DEFAULT_ADMIN_ROLE)
	{
		require(instantPoolOwner != _address, "Old address == new address");

		_revokeRole(INSTANT_POOL_OWNER, instantPoolOwner);
		instantPoolOwner = _address;
		_setupRole(INSTANT_POOL_OWNER, _address);

		emit SetInstantPoolOwner(_address);
	}

	function setTreasury(address _address)
		external
		override
		onlyRole(DEFAULT_ADMIN_ROLE)
	{
		treasury = _address;

		emit SetTreasury(_address);
	}

	function setValidatorRegistry(address _address)
		external
		override
		onlyRole(DEFAULT_ADMIN_ROLE)
	{
		validatorRegistry = _address;

		emit SetValidatorRegistry(_address);
	}

	function setFxStateRootTunnel(address _address)
		external
		override
		onlyRole(DEFAULT_ADMIN_ROLE)
	{
		fxStateRootTunnel = _address;

		emit SetFxStateRootTunnel(_address);
	}

	/**
	 * @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;

		emit SetVersion(_version);
	}

	////////////////////////////////////////////////////////////
	/////                                                    ///
	/////                 ***Getters***                      ///
	/////                                                    ///
	////////////////////////////////////////////////////////////

	/**
	 * @dev Helper function for that returns total pooled MATIC
	 * @return Total pooled MATIC
	 */
	function getTotalStakeAcrossAllValidators()
		public
		view
		override
		returns (uint256)
	{
		uint256 totalStake;
		uint256[] memory validators = IValidatorRegistry(validatorRegistry)
			.getValidators();
		for (uint256 i = 0; i < validators.length; ++i) {
			address validatorShare = IStakeManager(stakeManager)
				.getValidatorContract(validators[i]);
			(uint256 currValidatorShare, ) = getTotalStake(
				IValidatorShare(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;
	}

	/**
	 * @dev Retrieves all withdrawal requests initiated by the given address
	 * @param _address - Address of an user
	 * @return userWithdrawalRequests array of user withdrawal requests
	 */
	function getUserWithdrawalRequests(address _address)
		external
		view
		override
		returns (WithdrawalRequest[] memory)
	{
		return userWithdrawalRequests[_address];
	}

	/**
	 * @dev Retrieves shares amount of a given withdrawal request
	 * @param _address - Address of an user
	 * @return _idx index of the withdrawal request
	 */
	function getSharesAmountOfUserWithdrawalRequest(
		address _address,
		uint256 _idx
	) external view override returns (uint256) {
		WithdrawalRequest memory userRequest = userWithdrawalRequests[_address][
			_idx
		];
		IValidatorShare validatorShare = IValidatorShare(
			userRequest.validatorAddress
		);
		IValidatorShare.DelegatorUnbond memory unbond = validatorShare
			.unbonds_new(address(this), userRequest.validatorNonce);

		return unbond.shares;
	}

	function getContracts()
		external
		view
		override
		returns (
			address _stakeManager,
			address _polygonERC20,
			address _validatorRegistry
		)
	{
		_stakeManager = stakeManager;
		_polygonERC20 = polygonERC20;
		_validatorRegistry = validatorRegistry;
	}
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (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 {
        __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:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, 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}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, 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}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, 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) {
        address owner = _msgSender();
        _approve(owner, spender, _allowances[owner][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) {
        address owner = _msgSender();
        uint256 currentAllowance = _allowances[owner][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, 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:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, 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 Spend `amount` form the allowance of `owner` toward `spender`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - 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 {}

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[45] private __gap;
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (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 {
    }

    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 virtual 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 virtual {
        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 virtual 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());
        }
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (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 `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

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

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

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

    /**
     * @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 {
        __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());
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// File: contracts/interfaces/IValidatorShare.sol



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

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

	function minAmount() external view returns (uint256);

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

	function validatorId() external view returns (uint256);

	function delegation() external view returns (bool);

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

	function sellVoucher_new(uint256 claimAmount, uint256 maximumSharesToBurn)
		external;

	function unstakeClaimTokens_new(uint256 unbondNonce) external;

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

	function withdrawRewards() external;

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

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

// File: contracts/interfaces/IValidatorRegistry.sol



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

/// @title IValidatorRegistry
/// @notice Node validator registry interface
interface IValidatorRegistry {
	function addValidator(uint256 _validatorId) external;

	function removeValidator(uint256 _validatorId) external;

	function setPreferredDepositValidatorId(uint256 _validatorId) external;

	function setPreferredWithdrawalValidatorId(uint256 _validatorId) external;

	function setMaticX(address _maticX) external;

	function setVersion(string memory _version) external;

	function togglePause() external;

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

	function preferredDepositValidatorId() external view returns (uint256);

	function preferredWithdrawalValidatorId() external view returns (uint256);

	function validatorIdExists(uint256 _validatorId)
		external
		view
		returns (bool);

	function getContracts()
		external
		view
		returns (
			address _stakeManager,
			address _polygonERC20,
			address _maticX
		);

	function getValidatorId(uint256 _index) external view returns (uint256);

	function getValidators() external view returns (uint256[] memory);

	event AddValidator(uint256 indexed _validatorId);
	event RemoveValidator(uint256 indexed _validatorId);
	event SetPreferredDepositValidatorId(uint256 indexed _validatorId);
	event SetPreferredWithdrawalValidatorId(uint256 indexed _validatorId);
	event SetMaticX(address _address);
	event SetVersion(string _version);
}

// File: contracts/interfaces/IStakeManager.sol



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

/// @title polygon stake manager interface.
/// @notice User to interact with the polygon stake manager.
interface IStakeManager {
	/// @notice Request unstake a validator.
	/// @param validatorId validator id.
	function unstake(uint256 validatorId) 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 migrate the staked tokens to another validator.
	/// @param fromValidatorId From validator id.
	/// @param toValidatorId To validator id.
	/// @param amount amount in Matic.
	function migrateDelegation(
		uint256 fromValidatorId,
		uint256 toValidatorId,
		uint256 amount
	) 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);

	// TODO: Remove it and use stakeFor instead
	function createValidator(uint256 _validatorId) external;
}

// File: contracts/interfaces/IMaticX.sol



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

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

import "./IValidatorShare.sol";
import "./IValidatorRegistry.sol";

/// @title MaticX interface.
interface IMaticX is IERC20Upgradeable {
	struct WithdrawalRequest {
		uint256 validatorNonce;
		uint256 requestEpoch;
		address validatorAddress;
	}

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

	function treasury() external view returns (address);

	function feePercent() external view returns (uint8);

	function instantPoolOwner() external view returns (address);

	function instantPoolMatic() external view returns (uint256);

	function instantPoolMaticX() external view returns (uint256);

	function fxStateRootTunnel() external view returns (address);

	function initialize(
		address _validatorRegistry,
		address _stakeManager,
		address _token,
		address _manager,
		address _instant_pool_manager,
		address _treasury
	) external;

	function provideInstantPoolMatic(uint256 _amount) external;

	function provideInstantPoolMaticX(uint256 _amount) external;

	function withdrawInstantPoolMaticX(uint256 _amount) external;

	function withdrawInstantPoolMatic(uint256 _amount) external;

	function mintMaticXToInstantPool() external;

	function swapMaticForMaticXViaInstantPool(uint256 _amount) external;

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

	function requestWithdraw(uint256 _amount) external;

	function claimWithdrawal(uint256 _idx) external;

	function withdrawRewards(uint256 _validatorId) external returns (uint256);

	function stakeRewardsAndDistributeFees(uint256 _validatorId) external;

	function migrateDelegation(
		uint256 _fromValidatorId,
		uint256 _toValidatorId,
		uint256 _amount
	) external;

	function togglePause() external;

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

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

	function mint(address _user, uint256 _amount) external;

	function setFeePercent(uint8 _feePercent) external;

	function setInstantPoolOwner(address _address) external;

	function setValidatorRegistry(address _address) external;

	function setTreasury(address _address) external;

	function setFxStateRootTunnel(address _address) external;

	function setVersion(string calldata _version) external;

	function getUserWithdrawalRequests(address _address)
		external
		view
		returns (WithdrawalRequest[] memory);

	function getSharesAmountOfUserWithdrawalRequest(
		address _address,
		uint256 _idx
	) external view returns (uint256);

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

	function getTotalStakeAcrossAllValidators() external view returns (uint256);

	function getTotalPooledMatic() external view returns (uint256);

	function getContracts()
		external
		view
		returns (
			address _stakeManager,
			address _polygonERC20,
			address _validatorRegistry
		);

	event Submit(address indexed _from, uint256 _amount);
	event Delegate(uint256 indexed _validatorId, uint256 _amountDelegated);
	event RequestWithdraw(
		address indexed _from,
		uint256 _amountMaticX,
		uint256 _amountMatic
	);
	event ClaimWithdrawal(
		address indexed _from,
		uint256 indexed _idx,
		uint256 _amountClaimed
	);
	event WithdrawRewards(uint256 indexed _validatorId, uint256 _rewards);
	event StakeRewards(uint256 indexed _validatorId, uint256 _amountStaked);
	event DistributeFees(address indexed _address, uint256 _amount);
	event MigrateDelegation(
		uint256 indexed _fromValidatorId,
		uint256 indexed _toValidatorId,
		uint256 _amount
	);
	event MintFromPolygon(address indexed _user, uint256 _amount);
	event SetFeePercent(uint8 _feePercent);
	event SetInstantPoolOwner(address _address);
	event SetTreasury(address _address);
	event SetValidatorRegistry(address _address);
	event SetFxStateRootTunnel(address _address);
	event SetVersion(string _version);
}

// File: contracts/interfaces/IFxStateRootTunnel.sol



// 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 setMaticX(address _maticX) 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 {
    }

    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;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (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 proxied contracts do not make use of 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 (last updated v4.5.0) (utils/Address.sol)

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

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

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

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev 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 {
    }

    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;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    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);
}