Address Details

contract

// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
import "@openzeppelin/contracts/utils/math/Math.sol";

import "./common/UsingRegistryUpgradeable.sol";
import "./common/UUPSOwnableUpgradeable.sol";
import "./interfaces/IAccount.sol";
import "./interfaces/IStakedCelo.sol";
import "./interfaces/IVote.sol";
import "./interfaces/IGroupHealth.sol";
import "./interfaces/ISpecificGroupStrategy.sol";
import "./interfaces/IDefaultStrategy.sol";
import "./Pausable.sol";
import "./common/Errors.sol";

/**
 * @title Manages the StakedCelo system, by controlling the minting and burning
 * of stCELO and implementing strategies for voting and unvoting of deposited or
 * withdrawn CELO.
 */
contract Manager is Errors, UUPSOwnableUpgradeable, UsingRegistryUpgradeable, Pausable {
    using EnumerableSet for EnumerableSet.AddressSet;

    /**
     * @notice An instance of the StakedCelo contract this Manager manages.
     */
    IStakedCelo internal stakedCelo;

    /**
     * @notice An instance of the Account contract this Manager manages.
     */
    IAccount internal account;

    /**
     * @notice OBSOLETE
     */
    EnumerableSet.AddressSet private activeGroups;

    /**
     * @notice OBSOLETE
     */
    EnumerableSet.AddressSet private deprecatedGroups;

    /**
     * @notice Contract used during Governance voting.
     */
    address public voteContract;

    /**
     * @notice An instance of the GroupHealth contract for the StakedCelo protocol.
     */
    IGroupHealth public groupHealth;

    /**
     * @notice An instance of the SpecificGroupStrategy contract for the StakedCelo protocol.
     */
    ISpecificGroupStrategy public specificGroupStrategy;

    /**
     * @notice An instance of the DefaultStrategy contract for the StakedCelo protocol.
     */
    IDefaultStrategy public defaultStrategy;

    /**
     * @notice address -> strategy used by an address
     * strategy: address(0) = default strategy
     * strategy: !address(0) = vote for the group at that address if allowed
     * by GroupHealth.isGroupValid, otherwise vote according to the default strategy
     */
    mapping(address => address) public strategies;

    /**
     * @notice Emitted when the vote contract is initially set or later modified.
     * @param voteContract The new vote contract address.
     */
    event VoteContractSet(address indexed voteContract);

    /**
     * @notice Emitted when the voting strategy changes.
     * @param group The group's address.
     */
    event StrategyChanged(address indexed group);

    /**
     * @notice Used when attempting to withdraw 0 value.
     */
    error ZeroWithdrawal();

    /**
     * @notice Used when a group does not meet the validator group health requirements.
     * @param group The group's address.
     */
    error GroupNotEligible(address group);

    /**
     * @notice Used when an `onlyStCelo` function is called by a non-stCELO contract.
     * @param caller `msg.sender` that called the function.
     */
    error CallerNotStakedCelo(address caller);

    /**
     * @notice Used when an `onlyStrategy` function
     * is called by a non-strategy contract.
     * @param caller `msg.sender` that called the function.
     */
    error CallerNotStrategy(address caller);

    /**
     * @notice Used when rebalancing to non-active nor specific group.
     * @param group The group's address.
     */
    error InvalidToGroup(address group);

    /**
     * @notice Used when rebalancing and fromGroup doesn't have any extra CELO.
     * @param group The group's address.
     * @param actualCelo The actual CELO value.
     * @param expectedCelo The expected CELO value.
     */
    error RebalanceNoExtraCelo(address group, uint256 actualCelo, uint256 expectedCelo);

    /**
     * @notice Used when rebalancing and toGroup has enough CELO.
     * @param group The group's address.
     * @param actualCelo The actual CELO value.
     * @param expectedCelo The expected CELO value.
     */
    error RebalanceEnoughCelo(address group, uint256 actualCelo, uint256 expectedCelo);

    /**
     * @notice Used when trying to overflow rebalance group that is not overflowing.
     * @param group The group's address.
     */
    error FromGroupNotOverflowing(address group);

    /**
     * @notice Used when trying to rebalance to a group that is overflowing.
     * @param group The group's address.
     */
    error ToGroupOverflowing(address group);

    /**
     * @dev Throws if called by any address other than StakedCelo.
     */
    modifier onlyStakedCelo() {
        if (address(stakedCelo) != msg.sender) {
            revert CallerNotStakedCelo(msg.sender);
        }
        _;
    }

    /**
     * @dev Throws if called by any address other than one of the strategy contracts.
     */
    modifier onlyStrategy() {
        if (
            address(defaultStrategy) != msg.sender && address(specificGroupStrategy) != msg.sender
        ) {
            revert CallerNotStrategy(msg.sender);
        }
        _;
    }

    /**
     * @notice Empty constructor for proxy implementation, `initializer` modifer ensures the
     * implementation gets initialized.
     */
    // solhint-disable-next-line no-empty-blocks
    constructor() initializer {}

    /**
     * @notice Initialize the contract with registry and owner.
     * @param _registry The address of the Celo Registry.
     * @param _owner The address of the contract owner.
     */
    function initialize(address _registry, address _owner) external initializer {
        _transferOwnership(_owner);
        __UsingRegistry_init(_registry);
    }

    /**
     * @notice Set this contract's dependencies in the StakedCelo system.
     * @dev The StakedCelo contracts all reference each other
     * so we need a way of setting these after all contracts are
     * deployed and initialized.
     * @param _stakedCelo the address of the StakedCelo contract.
     * @param _account The address of the Account contract.
     * @param _vote The address of the Vote contract.
     * @param _groupHealth The address of the GroupHealth contract.
     * @param _specificGroupStrategy The address of the SpecificGroupStrategy contract.
     * @param _defaultStrategy The address of the DefaultStrategy contract.
     */
    function setDependencies(
        address _stakedCelo,
        address _account,
        address _vote,
        address _groupHealth,
        address _specificGroupStrategy,
        address _defaultStrategy
    ) external onlyOwner {
        if (
            _stakedCelo == address(0) ||
            _account == address(0) ||
            _vote == address(0) ||
            _groupHealth == address(0) ||
            _specificGroupStrategy == address(0) ||
            _defaultStrategy == address(0)
        ) {
            revert AddressZeroNotAllowed();
        }

        stakedCelo = IStakedCelo(_stakedCelo);
        account = IAccount(_account);
        voteContract = _vote;
        groupHealth = IGroupHealth(_groupHealth);
        specificGroupStrategy = ISpecificGroupStrategy(_specificGroupStrategy);
        defaultStrategy = IDefaultStrategy(_defaultStrategy);
        emit VoteContractSet(_vote);
    }

    /**
     * @notice Sets that address permissioned to pause/unpause this contract to
     * the owner of this contract.
     */
    function setPauser() external onlyOwner {
        _setPauser(owner());
    }

    /**
     * @notice Used to withdraw CELO from the system, in exchange for burning
     * stCELO.
     * @param stCeloAmount The amount of stCELO to burn.
     * @dev Calculates the CELO amount based on the ratio of outstanding stCELO
     * and the total amount of CELO owned and used for voting by Account. See
     * `toCelo`.
     * @dev The funds need to be withdrawn using calls to `Account.withdraw` and
     * `Account.finishPendingWithdrawal`.
     */
    function withdraw(uint256 stCeloAmount) external onlyWhenNotPaused {
        (
            address[] memory groupsWithdrawn,
            uint256[] memory withdrawalsPerGroup
        ) = distributeWithdrawals(stCeloAmount, strategies[msg.sender], false);
        account.scheduleWithdrawals(msg.sender, groupsWithdrawn, withdrawalsPerGroup);

        stakedCelo.burn(msg.sender, stCeloAmount);
    }

    /**
     * @notice Revokes votes on already voted proposal.
     * @param proposalId The ID of the proposal to revoke from.
     * @param index The index of the proposal ID in `dequeued`.
     */
    function revokeVotes(uint256 proposalId, uint256 index) external onlyWhenNotPaused {
        IVote vote = IVote(voteContract);

        (uint256 totalYesVotes, uint256 totalNoVotes, uint256 totalAbstainVotes) = vote.revokeVotes(
            msg.sender,
            proposalId
        );

        account.votePartially(proposalId, index, totalYesVotes, totalNoVotes, totalAbstainVotes);
    }

    /**
     * @notice Unlock balance of vote stCELO and update beneficiary vote history.
     * @param beneficiary The address to be unlocked.
     */
    function updateHistoryAndReturnLockedStCeloInVoting(address beneficiary)
        external
        onlyWhenNotPaused
        returns (uint256)
    {
        IVote vote = IVote(voteContract);
        return vote.updateHistoryAndReturnLockedStCeloInVoting(beneficiary);
    }

    /**
     * @notice Used to deposit CELO into the StakedCelo system. The user will
     * receive an amount of stCELO proportional to their contribution. The CELO
     * will be scheduled to be voted for with the Account contract.
     * The CELO will be distributed based on address strategy.
     */
    function deposit() external payable onlyWhenNotPaused {
        uint256 stCeloAmount = toStakedCelo(msg.value);
        (address[] memory finalGroups, uint256[] memory finalVotes) = distributeVotes(
            msg.value,
            stCeloAmount,
            strategies[msg.sender]
        );

        stakedCelo.mint(msg.sender, stCeloAmount);
        account.scheduleVotes{value: msg.value}(finalGroups, finalVotes);
    }

    /**
     * @notice Returns which strategy an address is using
     * address(0) = default strategy
     * !address(0) = voting for specific validator group.
     * Unhealthy and blocked strategies are reverted to default.
     * @param accountAddress The account address.
     * @return The strategy.
     */
    function getAddressStrategy(address accountAddress) external view returns (address) {
        address strategy = strategies[accountAddress];
        if (
            strategy != address(0) &&
            (specificGroupStrategy.isBlockedGroup(strategy) || !groupHealth.isGroupValid(strategy))
        ) {
            // strategy not allowed revert to default strategy
            return address(0);
        }

        return strategy;
    }

    /**
     * @notice Returns the storage, major, minor, and patch version of the contract.
     * @return Storage version of the contract.
     * @return Major version of the contract.
     * @return Minor version of the contract.
     * @return Patch version of the contract.
     */
    function getVersionNumber()
        external
        pure
        returns (
            uint256,
            uint256,
            uint256,
            uint256
        )
    {
        return (1, 3, 1, 0);
    }

    /**
     * @notice Whenever stCELO is being transferd we will check whether origin and target
     * account use same strategy. If strategy differs we will schedule votes for transfer.
     * @param from The from account.
     * @param to The to account.
     * @param stCeloAmount The stCELO amount.
     */
    function transfer(
        address from,
        address to,
        uint256 stCeloAmount
    ) public onlyStakedCelo {
        _transfer(strategies[from], strategies[to], stCeloAmount);
    }

    /**
     * @notice Allows account to change strategy.
     * address(0) = default strategy
     * !address(0) = voting for allowed validator group. Group needs to be in allowed
     * @param newStrategy The from account.
     */
    function changeStrategy(address newStrategy) public onlyWhenNotPaused {
        if (
            newStrategy != address(0) &&
            (specificGroupStrategy.isBlockedGroup(newStrategy) ||
                !groupHealth.isGroupValid(newStrategy))
        ) {
            revert GroupNotEligible(newStrategy);
        }

        uint256 stCeloAmount = stakedCelo.balanceOf(msg.sender);
        if (stCeloAmount != 0) {
            _transfer(strategies[msg.sender], newStrategy, stCeloAmount);
        }

        strategies[msg.sender] = newStrategy;
        emit StrategyChanged(newStrategy);
    }

    /**
     * @notice Unlock vote balance of stCELO.
     * @param accountAddress The account to be unlocked.
     */
    function unlockBalance(address accountAddress) public {
        stakedCelo.unlockVoteBalance(accountAddress);
    }

    /**
     * @notice Rebalances CELO between groups that have incorrect CELO-stCELO ratio.
     * `fromGroup` is required to have more CELO than it should and `toGroup` needs
     * to have less CELO than it should.
     * @param fromGroup The from group.
     * @param toGroup The to group.
     */
    function rebalance(address fromGroup, address toGroup) public onlyWhenNotPaused {
        if (!defaultStrategy.isActive(toGroup) && specificGroupStrategy.isBlockedGroup(toGroup)) {
            // rebalancing to deactivated/non-existent group is not allowed
            revert InvalidToGroup(toGroup);
        }

        (uint256 expectedFromCelo, uint256 actualFromCelo) = getExpectedAndActualCeloForGroup(
            fromGroup
        );
        if (actualFromCelo <= expectedFromCelo) {
            // fromGroup needs to have more CELO than it should
            revert RebalanceNoExtraCelo(fromGroup, actualFromCelo, expectedFromCelo);
        }

        (uint256 expectedToCelo, uint256 actualToCelo) = getExpectedAndActualCeloForGroup(toGroup);

        if (actualToCelo >= expectedToCelo) {
            // toGroup needs to have less CELO than it should
            revert RebalanceEnoughCelo(toGroup, actualToCelo, expectedToCelo);
        }

        uint256 receivableVotes = getReceivableVotesForGroup(toGroup);

        if (receivableVotes == 0) {
            revert ToGroupOverflowing(toGroup);
        }

        uint256 toMove = Math.min(
            Math.min(actualFromCelo - expectedFromCelo, expectedToCelo - actualToCelo),
            receivableVotes
        );

        scheduleRebalanceTransfer(fromGroup, toGroup, toMove);
    }

    /**
     * @notice Rebalance according to CELO overflow rather than stCELO ratio.
     * If one of the groups is overflowing and there are still some votes that
     * are scheduled for the group, this function allows to transfer these
     * votes to any active group in protocol that is not overflowing yet.
     * @param fromGroup The group to unschedule votes from.
     * @param toGroup The group to schedule votes to.
     */
    function rebalanceOverflow(address fromGroup, address toGroup) public onlyWhenNotPaused {
        if (!defaultStrategy.isActive(toGroup)) {
            revert InvalidToGroup(toGroup);
        }

        uint256 fromReceivableVotesByElection = getElectionReceivableVotes(fromGroup);

        uint256 scheduledVotesToCancel = account.scheduledRevokeForGroup(fromGroup) +
            account.scheduledWithdrawalsForGroup(fromGroup);
        uint256 scheduledVotes = account.scheduledVotesForGroup(fromGroup);

        uint256 protocolScheduledVotes = scheduledVotes > scheduledVotesToCancel
            ? scheduledVotes - scheduledVotesToCancel
            : 0;

        uint256 overflowingCelo = protocolScheduledVotes > fromReceivableVotesByElection
            ? protocolScheduledVotes - fromReceivableVotesByElection
            : 0;

        if (overflowingCelo == 0) {
            revert FromGroupNotOverflowing(fromGroup);
        }

        uint256 toReceivableVotes = getReceivableVotesForGroup(toGroup);
        if (toReceivableVotes == 0) {
            revert ToGroupOverflowing(toGroup);
        }

        uint256 toMove = Math.min(overflowingCelo, toReceivableVotes);
        scheduleRebalanceTransfer(fromGroup, toGroup, toMove);
    }

    /**
     * @notice Allows strategy to initiate transfer without any checks.
     * This method is supposed to be used for transfers between groups
     * only within strategy
     * @param fromGroups The groups the deposited CELO is intended to be revoked from.
     * @param fromVotes The amount of CELO scheduled to be revoked from each respective group.
     * @param toGroups The groups the transferred CELO is intended to vote for.
     * @param toVotes The amount of CELO to schedule for each respective `toGroups`.
     */
    function scheduleTransferWithinStrategy(
        address[] calldata fromGroups,
        address[] calldata toGroups,
        uint256[] calldata fromVotes,
        uint256[] calldata toVotes
    ) public onlyStrategy {
        account.scheduleTransfer(fromGroups, fromVotes, toGroups, toVotes);
    }

    /**
     * @notice Votes on a proposal in the referendum stage.
     * @param proposalId The ID of the proposal to vote on.
     * @param index The index of the proposal ID in `dequeued`.
     * @param yesVotes The yes votes weight.
     * @param noVotes The no votes weight.
     * @param abstainVotes The abstain votes weight.
     */
    function voteProposal(
        uint256 proposalId,
        uint256 index,
        uint256 yesVotes,
        uint256 noVotes,
        uint256 abstainVotes
    ) public onlyWhenNotPaused {
        IVote vote = IVote(voteContract);

        (
            uint256 stCeloUsedForVoting,
            uint256 totalYesVotes,
            uint256 totalNoVotes,
            uint256 totalAbstainVotes
        ) = vote.voteProposal(msg.sender, proposalId, yesVotes, noVotes, abstainVotes);

        stakedCelo.lockVoteBalance(msg.sender, stCeloUsedForVoting);
        account.votePartially(proposalId, index, totalYesVotes, totalNoVotes, totalAbstainVotes);
    }

    /**
     * @notice Returns expected CELO amount voted for by Account contract
     * vs actual amount voted for by Account contract.
     * @param group The group.
     * @return expectedCelo The CELO which group should have.
     * @return actualCelo The CELO which group has.
     */
    function getExpectedAndActualCeloForGroup(address group)
        public
        view
        returns (uint256 expectedCelo, uint256 actualCelo)
    {
        uint256 celoScheduled = account.votesForGroup(group) +
            account.scheduledVotesForGroup(group);
        uint256 celoToRemove = account.scheduledRevokeForGroup(group) +
            account.scheduledWithdrawalsForGroup(group);
        if (celoToRemove > celoScheduled) {
            return (celoToRemove - celoScheduled, 0);
        }

        actualCelo = celoScheduled - celoToRemove;

        bool isSpecificGroupStrategy = !specificGroupStrategy.isBlockedGroup(group);
        bool isActiveGroup = defaultStrategy.isActive(group);

        uint256 stCeloFromSpecificStrategy;
        uint256 stCeloFromDefaultStrategy;

        if (isSpecificGroupStrategy) {
            uint256 overflow;
            uint256 unhealthy;
            (stCeloFromSpecificStrategy, overflow, unhealthy) = specificGroupStrategy
                .getStCeloInGroup(group);

            uint256 toSubtract = overflow + unhealthy;
            stCeloFromSpecificStrategy -= Math.min(stCeloFromSpecificStrategy, toSubtract);
        }

        if (isActiveGroup) {
            stCeloFromDefaultStrategy = defaultStrategy.stCeloInGroup(group);
        }
        expectedCelo = toCelo(stCeloFromSpecificStrategy + stCeloFromDefaultStrategy);
    }

    /**
     * @notice Computes the amount of stCELO that should be minted for a given
     * amount of CELO deposited.
     * @param celoAmount The amount of CELO deposited.
     * @return The amount of stCELO that should be minted.
     */
    function toStakedCelo(uint256 celoAmount) public view returns (uint256) {
        uint256 stCeloSupply = stakedCelo.totalSupply();
        uint256 celoBalance = account.getTotalCelo();
        if (stCeloSupply == 0 || celoBalance == 0) {
            return celoAmount;
        }

        return (celoAmount * stCeloSupply) / celoBalance;
    }

    /**
     * @notice Computes the amount of CELO that should be withdrawn for a given
     * amount of stCELO burned.
     * @param stCeloAmount The amount of stCELO burned.
     * @return The amount of CELO that should be withdrawn.
     */
    function toCelo(uint256 stCeloAmount) public view returns (uint256) {
        uint256 stCeloSupply = stakedCelo.totalSupply();
        uint256 celoBalance = account.getTotalCelo();

        if (stCeloSupply == 0 || celoBalance == 0) {
            return stCeloAmount;
        }

        return (stCeloAmount * celoBalance) / stCeloSupply;
    }

    /**
     * Returns votes count that can be received by group through stCELO protocol.
     * @param group The group that can receive votes.
     * @return The amount of CELO that can be received by group though stCELO protocol.
     */
    function getReceivableVotesForGroup(address group) public view returns (uint256) {
        uint256 receivableVotes = getElectionReceivableVotes(group);
        if (receivableVotes == 0) {
            return 0;
        }

        uint256 totalVotesForGroupByAccount = getElection().getTotalVotesForGroupByAccount(
            group,
            address(account)
        );
        uint256 votesForGroupByAccountInProtocol = account.getCeloForGroup(group);

        receivableVotes += totalVotesForGroupByAccount;

        if (receivableVotes < votesForGroupByAccountInProtocol) {
            return 0;
        }

        return receivableVotes - votesForGroupByAccountInProtocol;
    }

    /**
     * @notice Distributes votes according to chosen strategy.
     * @param votes The amount of votes to distribute.
     * @param stCeloAmount The amount of stCELO that was minted.
     * @param strategy The chosen strategy.
     */
    function distributeVotes(
        uint256 votes,
        uint256 stCeloAmount,
        address strategy
    ) private returns (address[] memory finalGroups, uint256[] memory finalVotes) {
        if (strategy != address(0)) {
            (finalGroups, finalVotes) = specificGroupStrategy.generateDepositVoteDistribution(
                strategy,
                votes,
                stCeloAmount
            );
        } else {
            (finalGroups, finalVotes) = defaultStrategy.generateDepositVoteDistribution(
                votes,
                address(0)
            );
        }

        return (finalGroups, finalVotes);
    }

    /**
     * @notice Distributes withdrawals according to chosen strategy.
     * @param stCeloAmount The amount of stCELO to be withdrawn.
     * @param strategy The strategy that will be used for withdrawal distribution.
     * @param isTransfer Whether or not withdrawal is calculated for transfer.
     **/
    function distributeWithdrawals(
        uint256 stCeloAmount,
        address strategy,
        bool isTransfer
    ) private returns (address[] memory, uint256[] memory) {
        uint256 celoAmount = toCelo(stCeloAmount);
        if (celoAmount == 0) {
            revert ZeroWithdrawal();
        }

        address[] memory groupsWithdrawn;
        uint256[] memory withdrawalsPerGroup;

        if (strategy != address(0)) {
            (groupsWithdrawn, withdrawalsPerGroup) = specificGroupStrategy
                .generateWithdrawalVoteDistribution(strategy, celoAmount, stCeloAmount, isTransfer);
        } else {
            (groupsWithdrawn, withdrawalsPerGroup) = defaultStrategy
                .generateWithdrawalVoteDistribution(celoAmount);
        }

        return (groupsWithdrawn, withdrawalsPerGroup);
    }

    /**
     * @notice Schedules transfer of CELO between strategies.
     * @param fromStrategy The from validator group.
     * @param toStrategy The to validator group.
     * @param stCeloAmount The stCELO amount.
     */
    function _transfer(
        address fromStrategy,
        address toStrategy,
        uint256 stCeloAmount
    ) private {
        if (fromStrategy == toStrategy) {
            // either both addresses use default strategy
            // or both addresses use same specific strategy
            return;
        }

        _transferWithoutChecks(fromStrategy, toStrategy, stCeloAmount);
    }

    /**
     * @notice Updates accounting of CELO between strategies.
     * @param fromStrategy The from validator group.
     * @param toStrategy The to validator group.
     * @param stCeloAmount The stCELO amount.
     */
    function _transferWithoutChecks(
        address fromStrategy,
        address toStrategy,
        uint256 stCeloAmount
    ) private {
        distributeWithdrawals(stCeloAmount, fromStrategy, true);
        distributeVotes(toCelo(stCeloAmount), stCeloAmount, toStrategy);
    }

    /**
     * @notice Schedules transfer between 2 groups.
     * @param fromGroup The group the deposited CELO is intended to be revoked from.
     * @param toGroup The group the transferred CELO is intended to vote for.
     * @param votes The amount of CELO to be transfered.
     */
    function scheduleRebalanceTransfer(
        address fromGroup,
        address toGroup,
        uint256 votes
    ) private {
        address[] memory fromGroups = new address[](1);
        address[] memory toGroups = new address[](1);
        uint256[] memory fromVotes = new uint256[](1);
        uint256[] memory toVotes = new uint256[](1);

        fromGroups[0] = fromGroup;
        fromVotes[0] = votes;
        toGroups[0] = toGroup;
        toVotes[0] = fromVotes[0];

        account.scheduleTransfer(fromGroups, fromVotes, toGroups, toVotes);
    }

    /**
     * Returns votes count that can be received by group directly in Election contract.
     * @param group The group that can receive votes.
     */
    function getElectionReceivableVotes(address group) private view returns (uint256) {
        uint256 receivable = getElection().getNumVotesReceivable(group);
        uint256 totalVotes = getElection().getTotalVotesForGroup(group);

        if (receivable < totalVotes) {
            return 0;
        }

        return receivable - totalVotes;
    }
}
        

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

import "./interfaces/IPausable.sol";
import "./common/Errors.sol";

/**
 * @title A helper contract to add pasuing functionality to a contract.
 * @notice Used to prevent/mitigate damage in case an exploit is found in the
 * extending contract.
 */
abstract contract Pausable is Errors, IPausable {
    /**
     * @notice The storage slot under which we store a boolean representing
     * whether or not the contract is currently paused.
     */
    bytes32 public constant PAUSED_POSITION =
        bytes32(uint256(keccak256("staked-celo.pausable.paused")) - 1);
    /**
     * @notice The storage slot under which we store an address representing the
     * address permissioned to pause/unpause this contract.
     */
    bytes32 public constant PAUSER_POSITION =
        bytes32(uint256(keccak256("staked-celo.pausable.pauser")) - 1);

    /**
     * Emitted when this contract is paused.
     */
    event ContractPaused();

    /**
     * Emitted when this contract is unpaused.
     */
    event ContractUnpaused();

    /**
     * @notice Emitted when the address authorized to pause/unpause the contract is
     * changed.
     * @param pauser THe new pauser.
     */
    event PauserSet(address pauser);

    /**
     * @notice Used when an `onlyWhenNotPaused` function is called while the
     * contract is paused.
     */
    error Paused();

    /**
     * @notice Used when an `onlyPauser` function is called with a different
     * address.
     */
    error OnlyPauser();

    /**
     * @notice Reverts if the contract is paused.
     */
    modifier onlyWhenNotPaused() {
        if (isPaused()) {
            revert Paused();
        }

        _;
    }

    /**
     * @notice Reverts if the caller is not the pauser.
     */
    modifier onlyPauser() {
        if (msg.sender != pauser()) {
            revert OnlyPauser();
        }

        _;
    }

    /**
     * @notice Pauses the contract.
     */
    function pause() public onlyPauser {
        _setPaused(true);
        emit ContractPaused();
    }

    /**
     * @notice Unpauses the contract.
     */
    function unpause() public onlyPauser {
        _setPaused(false);
        emit ContractUnpaused();
    }

    /**
     * @notice Returns whether or not the contract is paused.
     * @return `true` if the contract is paused, `false` otherwise.
     */
    function isPaused() public view returns (bool) {
        bool paused;
        bytes32 pausedPosition = PAUSED_POSITION;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            paused := sload(pausedPosition)
        }
        return paused;
    }

    /**
     * @notice Returns the address permissioned to pause/unpause this contract.
     */
    function pauser() public view returns (address) {
        address pauserAddress;
        bytes32 pauserPosition = PAUSER_POSITION;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            pauserAddress := sload(pauserPosition)
        }
        return pauserAddress;
    }

    /**
     * @notice Sets the contract's paused state.
     * @param paused `true` for paused, `false` for unpaused.
     */
    function _setPaused(bool paused) internal {
        bytes32 pausedPosition = PAUSED_POSITION;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(pausedPosition, paused)
        }
    }

    /**
     * @notice Sets the address permissioned to pause this contract.
     * @param _pauser The new pauser.
     * @dev This should be wrapped by the inheriting contract, likely in a
     * permissioned function like `onlyOwner`.
     */
    function _setPauser(address _pauser) internal {
        if (_pauser == address(0)) {
            revert AddressZeroNotAllowed();
        }
        bytes32 pauserPosition = PAUSER_POSITION;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(pauserPosition, _pauser)
        }
        emit PauserSet(_pauser);
    }
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

/**
 * @title Provides some common general errors.
 */
abstract contract Errors {
    /**
     * @notice Used when attempting to pass in address zero where not allowed.
     */
    error AddressZeroNotAllowed();
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IVote {
    function updateHistoryAndReturnLockedStCeloInVoting(address beneficiary)
        external
        returns (uint256);

    function voteProposal(
        address accountVoter,
        uint256 proposalId,
        uint256 yesVotes,
        uint256 noVotes,
        uint256 abstainVotes
    )
        external
        returns (
            uint256 stCeloUsedForVoting,
            uint256 totalYesVotes,
            uint256 totalNoVotes,
            uint256 totalAbstainVotes
        );

    function revokeVotes(address accountVoter, uint256 proposalId)
        external
        returns (
            uint256 totalYesVotes,
            uint256 totalNoVotes,
            uint256 totalAbstainVotes
        );
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IAccount {
    function scheduleVotes(address[] calldata group, uint256[] calldata votes) external payable;

    function scheduleTransfer(
        address[] calldata fromGroups,
        uint256[] calldata fromVotes,
        address[] calldata toGroups,
        uint256[] calldata toVotess
    ) external;

    function scheduleWithdrawals(
        address beneficiary,
        address[] calldata group,
        uint256[] calldata withdrawals
    ) external;

    function votePartially(
        uint256 proposalId,
        uint256 index,
        uint256 yesVotes,
        uint256 noVotes,
        uint256 abstainVotes
    ) external;

    function getTotalCelo() external view returns (uint256);

    function getCeloForGroup(address) external view returns (uint256);

    function scheduledVotesForGroup(address group) external view returns (uint256);

    function scheduledRevokeForGroup(address group) external view returns (uint256);

    function scheduledWithdrawalsForGroup(address group) external view returns (uint256);

    function votesForGroup(address group) external view returns (uint256);
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IAccounts {
    function isAccount(address) external view returns (bool);

    function voteSignerToAccount(address) external view returns (address);

    function validatorSignerToAccount(address) external view returns (address);

    function attestationSignerToAccount(address) external view returns (address);

    function signerToAccount(address) external view returns (address);

    function getAttestationSigner(address) external view returns (address);

    function getValidatorSigner(address) external view returns (address);

    function getVoteSigner(address) external view returns (address);

    function hasAuthorizedVoteSigner(address) external view returns (bool);

    function hasAuthorizedValidatorSigner(address) external view returns (bool);

    function hasAuthorizedAttestationSigner(address) external view returns (bool);

    function setAccountDataEncryptionKey(bytes calldata) external;

    function setMetadataURL(string calldata) external;

    function setName(string calldata) external;

    function setWalletAddress(
        address,
        uint8,
        bytes32,
        bytes32
    ) external;

    function setAccount(
        string calldata,
        bytes calldata,
        address,
        uint8,
        bytes32,
        bytes32
    ) external;

    function getDataEncryptionKey(address) external view returns (bytes memory);

    function getWalletAddress(address) external view returns (address);

    function getMetadataURL(address) external view returns (string memory);

    function batchGetMetadataURL(address[] calldata)
        external
        view
        returns (uint256[] memory, bytes memory);

    function getName(address) external view returns (string memory);

    function authorizeVoteSigner(
        address,
        uint8,
        bytes32,
        bytes32
    ) external;

    function authorizeValidatorSigner(
        address,
        uint8,
        bytes32,
        bytes32
    ) external;

    function authorizeValidatorSignerWithPublicKey(
        address,
        uint8,
        bytes32,
        bytes32,
        bytes calldata
    ) external;

    function authorizeValidatorSignerWithKeys(
        address,
        uint8,
        bytes32,
        bytes32,
        bytes calldata,
        bytes calldata,
        bytes calldata
    ) external;

    function authorizeAttestationSigner(
        address,
        uint8,
        bytes32,
        bytes32
    ) external;

    function createAccount() external returns (bool);
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IElection {
    function vote(
        address,
        uint256,
        address,
        address
    ) external returns (bool);

    function activate(address) external returns (bool);

    function activateForAccount(address, address) external returns (bool);

    function revokeActive(
        address,
        uint256,
        address,
        address,
        uint256
    ) external returns (bool);

    function revokeAllActive(
        address,
        address,
        address,
        uint256
    ) external returns (bool);

    function revokePending(
        address,
        uint256,
        address,
        address,
        uint256
    ) external returns (bool);

    function markGroupIneligible(address) external;

    function markGroupEligible(
        address,
        address,
        address
    ) external;

    function forceDecrementVotes(
        address,
        uint256,
        address[] calldata,
        address[] calldata,
        uint256[] calldata
    ) external returns (uint256);

    // only owner
    function setElectableValidators(uint256, uint256) external returns (bool);

    function setMaxNumGroupsVotedFor(uint256) external returns (bool);

    function setElectabilityThreshold(uint256) external returns (bool);

    // only VM
    function distributeEpochRewards(
        address,
        uint256,
        address,
        address
    ) external;

    function allowedToVoteOverMaxNumberOfGroups(address) external returns (bool);

    function setAllowedToVoteOverMaxNumberOfGroups(bool flag) external;

    // view functions
    function electValidatorSigners() external view returns (address[] memory);

    function electNValidatorSigners(uint256, uint256) external view returns (address[] memory);

    function getElectableValidators() external view returns (uint256, uint256);

    function getElectabilityThreshold() external view returns (uint256);

    function getNumVotesReceivable(address) external view returns (uint256);

    function getTotalVotes() external view returns (uint256);

    function getActiveVotes() external view returns (uint256);

    function getTotalVotesByAccount(address) external view returns (uint256);

    function getPendingVotesForGroupByAccount(address, address) external view returns (uint256);

    function getActiveVotesForGroupByAccount(address, address) external view returns (uint256);

    function getTotalVotesForGroupByAccount(address, address) external view returns (uint256);

    function getActiveVoteUnitsForGroupByAccount(address, address) external view returns (uint256);

    function getTotalVotesForGroup(address) external view returns (uint256);

    function getActiveVotesForGroup(address) external view returns (uint256);

    function getPendingVotesForGroup(address) external view returns (uint256);

    function getGroupEligibility(address) external view returns (bool);

    function getGroupEpochRewards(
        address,
        uint256,
        uint256[] calldata
    ) external view returns (uint256);

    function getGroupsVotedForByAccount(address) external view returns (address[] memory);

    function getEligibleValidatorGroups() external view returns (address[] memory);

    function getTotalVotesForEligibleValidatorGroups()
        external
        view
        returns (address[] memory, uint256[] memory);

    function getCurrentValidatorSigners() external view returns (address[] memory);

    function canReceiveVotes(address, uint256) external view returns (bool);

    function hasActivatablePendingVotes(address, address) external view returns (bool);

    function maxNumGroupsVotedFor() external view returns (uint256);

    function validatorSignerAddressFromCurrentSet(uint256 index) external view returns (address);

    function numberValidatorsInCurrentSet() external view returns (uint256);

    function getEpochNumber() external view returns (uint256);
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IPausable {
    function pause() external;

    function unpause() external;

    function isPaused() external returns (bool);
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IRegistry {
    function setAddressFor(string calldata, address) external;

    function getAddressForOrDie(bytes32) external view returns (address);

    function getAddressFor(bytes32) external view returns (address);

    function getAddressForStringOrDie(string calldata identifier) external view returns (address);

    function getAddressForString(string calldata identifier) external view returns (address);

    function isOneOf(bytes32[] calldata, address) external view returns (bool);
}
          

// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IGoldToken {
    function transfer(address to, uint256 value) external returns (bool);

    function transferWithComment(
        address to,
        uint256 value,
        string calldata comment
    ) external returns (bool);

    function approve(address spender, uint256 value) external returns (bool);

    function increaseAllowance(address spender, uint256 value) external returns (bool);

    function decreaseAllowance(address spender, uint256 value) external returns (bool);

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);

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

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

    function decimals() external view returns (uint8);

    function totalSupply() external view returns (uint256);

    function allowance(address owner, address spender) external view returns (uint256);

    function balanceOf(address owner) external view returns (uint256);
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IGovernance {
    function votePartially(
        uint256 proposalId,
        uint256 index,
        uint256 yesVotes,
        uint256 noVotes,
        uint256 abstainVotes
    ) external returns (bool);

    function getProposal(uint256 proposalId)
        external
        view
        returns (
            address,
            uint256,
            uint256,
            uint256,
            string memory
        );

    function getReferendumStageDuration() external view returns (uint256);
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface ILockedGold {
    function lock() external payable;

    function incrementNonvotingAccountBalance(address, uint256) external;

    function unlock(uint256) external;

    function relock(uint256, uint256) external;

    function withdraw(uint256) external;

    function slash(
        address account,
        uint256 penalty,
        address reporter,
        uint256 reward,
        address[] calldata lessers,
        address[] calldata greaters,
        uint256[] calldata indices
    ) external;

    function decrementNonvotingAccountBalance(address, uint256) external;

    function unlockingPeriod() external view returns (uint256);

    function getAccountTotalLockedGold(address) external view returns (uint256);

    function getTotalLockedGold() external view returns (uint256);

    function getPendingWithdrawal(address, uint256) external view returns (uint256, uint256);

    function getSlashingWhitelist() external view returns (bytes32[] memory);

    function getPendingWithdrawals(address)
        external
        view
        returns (uint256[] memory, uint256[] memory);

    function getTotalPendingWithdrawals(address) external view returns (uint256);

    function isSlasher(address) external view returns (bool);

    function owner() external view returns (address);

    function getAccountNonvotingLockedGold(address account) external view returns (uint256);
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IStakedCelo {
    function totalSupply() external view returns (uint256);

    function mint(address, uint256) external;

    function burn(address, uint256) external;

    function transfer(address, uint256) external returns (bool);

    function transferFrom(
        address,
        address,
        uint256
    ) external returns (bool);

    function balanceOf(address account) external view returns (uint256);

    function lockVoteBalance(address account, uint256 amount) external;

    function unlockVoteBalance(address account) external;

    function lockedVoteBalanceOf(address account) external view returns (uint256);
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity ^0.8.11;

interface IValidators {
    function registerValidator(
        bytes calldata,
        bytes calldata,
        bytes calldata
    ) external returns (bool);

    function deregisterValidator(uint256) external returns (bool);

    function affiliate(address) external returns (bool);

    function deaffiliate() external returns (bool);

    function updateBlsPublicKey(bytes calldata, bytes calldata) external returns (bool);

    function registerValidatorGroup(uint256) external returns (bool);

    function deregisterValidatorGroup(uint256) external returns (bool);

    function addMember(address) external returns (bool);

    function addFirstMember(
        address,
        address,
        address
    ) external returns (bool);

    function removeMember(address) external returns (bool);

    function reorderMember(
        address,
        address,
        address
    ) external returns (bool);

    function updateCommission() external;

    function setNextCommissionUpdate(uint256) external;

    function resetSlashingMultiplier() external;

    // only owner
    function setCommissionUpdateDelay(uint256) external;

    function setMaxGroupSize(uint256) external returns (bool);

    function setMembershipHistoryLength(uint256) external returns (bool);

    function setValidatorScoreParameters(uint256, uint256) external returns (bool);

    function setGroupLockedGoldRequirements(uint256, uint256) external returns (bool);

    function setValidatorLockedGoldRequirements(uint256, uint256) external returns (bool);

    function setSlashingMultiplierResetPeriod(uint256) external;

    // view functions
    function getMaxGroupSize() external view returns (uint256);

    function getCommissionUpdateDelay() external view returns (uint256);

    function getValidatorScoreParameters() external view returns (uint256, uint256);

    function getMembershipHistory(address)
        external
        view
        returns (
            uint256[] memory,
            address[] memory,
            uint256,
            uint256
        );

    function calculateEpochScore(uint256) external view returns (uint256);

    function calculateGroupEpochScore(uint256[] calldata) external view returns (uint256);

    function getAccountLockedGoldRequirement(address) external view returns (uint256);

    function meetsAccountLockedGoldRequirements(address) external view returns (bool);

    function getValidatorBlsPublicKeyFromSigner(address) external view returns (bytes memory);

    function getValidator(address account)
        external
        view
        returns (
            bytes memory,
            bytes memory,
            address,
            uint256,
            address
        );

    function getValidatorGroup(address)
        external
        view
        returns (
            address[] memory,
            uint256,
            uint256,
            uint256,
            uint256[] memory,
            uint256,
            uint256
        );

    function getGroupNumMembers(address) external view returns (uint256);

    function getTopGroupValidators(address, uint256) external view returns (address[] memory);

    function getGroupsNumMembers(address[] calldata accounts)
        external
        view
        returns (uint256[] memory);

    function getNumRegisteredValidators() external view returns (uint256);

    function groupMembershipInEpoch(
        address,
        uint256,
        uint256
    ) external view returns (address);

    // only registered contract
    function updateEcdsaPublicKey(
        address,
        address,
        bytes calldata
    ) external returns (bool);

    function updatePublicKeys(
        address,
        address,
        bytes calldata,
        bytes calldata,
        bytes calldata
    ) external returns (bool);

    function getValidatorLockedGoldRequirements() external view returns (uint256, uint256);

    function getGroupLockedGoldRequirements() external view returns (uint256, uint256);

    function getRegisteredValidators() external view returns (address[] memory);

    function getRegisteredValidatorSigners() external view returns (address[] memory);

    function getRegisteredValidatorGroups() external view returns (address[] memory);

    function isValidatorGroup(address) external view returns (bool);

    function isValidator(address) external view returns (bool);

    function getValidatorGroupSlashingMultiplier(address) external view returns (uint256);

    function getMembershipInLastEpoch(address) external view returns (address);

    function getMembershipInLastEpochFromSigner(address) external view returns (address);

    // only VM
    function updateValidatorScoreFromSigner(address, uint256) external;

    function distributeEpochPaymentsFromSigner(address, uint256) external returns (uint256);

    // only slasher
    function forceDeaffiliateIfValidator(address) external;

    function halveSlashingMultiplier(address) external;
}
          

// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IGroupHealth {
    function isGroupValid(address group) external view returns (bool);
}
          

// 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 Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

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

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

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

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

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

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

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

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

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

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

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

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
          

// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface IDefaultStrategy {
    function generateDepositVoteDistribution(uint256 celoAmount, address depositGroupToIgnore)
        external
        returns (address[] memory finalGroups, uint256[] memory finalVotes);

    function generateWithdrawalVoteDistribution(uint256 celoAmount)
        external
        returns (address[] memory finalGroups, uint256[] memory finalVotes);

    function activateGroup(address group) external;

    function isActive(address group) external view returns (bool);

    function getNumberOfGroups() external view returns (uint256);

    function stCeloInGroup(address group) external view returns (uint256);
}
          

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

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a / b + (a % b == 0 ? 0 : 1);
    }
}
          

// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

import "@openzeppelin/contracts/proxy/utils/UUPSUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";

/**
 * @title A contract that links UUPSUUpgradeable with OwanbleUpgradeable to gate upgrades.
 */
abstract contract UUPSOwnableUpgradeable is UUPSUpgradeable, OwnableUpgradeable {
    /**
     * @notice Guard method for UUPS (Universal Upgradable Proxy Standard)
     * See: https://docs.openzeppelin.com/contracts/4.x/api/proxy#transparent-vs-uups
     * @dev This methods overrides the virtual one in UUPSUpgradeable and
     * adds the onlyOwner modifer.
     */
    // solhint-disable-next-line no-empty-blocks
    function _authorizeUpgrade(address) internal override onlyOwner {}
}
          

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

pragma solidity ^0.8.0;

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}
          

//SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";

import "../interfaces/IAccounts.sol";
import "../interfaces/IElection.sol";
import "../interfaces/IGoldToken.sol";
import "../interfaces/ILockedGold.sol";
import "../interfaces/IRegistry.sol";
import "../interfaces/IGovernance.sol";
import "../interfaces/IValidators.sol";

/**
 * @title A helper for getting Celo core contracts from the Registry.
 */
abstract contract UsingRegistryUpgradeable is Initializable {
    /// @notice The canonical address of the Registry.
    address internal constant CANONICAL_REGISTRY = 0x000000000000000000000000000000000000ce10;

    /// @notice The registry ID for the Accounts contract.
    bytes32 private constant ACCOUNTS_REGISTRY_ID = keccak256(abi.encodePacked("Accounts"));

    /// @notice The registry ID for the Election contract.
    bytes32 private constant ELECTION_REGISTRY_ID = keccak256(abi.encodePacked("Election"));

    /// @notice The registry ID for the GoldToken contract.
    bytes32 private constant GOLD_TOKEN_REGISTRY_ID = keccak256(abi.encodePacked("GoldToken"));

    /// @notice The registry ID for the LockedGold contract.
    bytes32 private constant LOCKED_GOLD_REGISTRY_ID = keccak256(abi.encodePacked("LockedGold"));

    /// @notice The registry ID for the Governance contract.
    bytes32 private constant GOVERNANCE_REGISTRY_ID = keccak256(abi.encodePacked("Governance"));

    /// @notice The registry ID for the Validator contract.
    bytes32 private constant VALIDATORS_REGISTRY_ID = keccak256(abi.encodePacked("Validators"));

    /// @notice The Registry.
    IRegistry public registry;

    /**
     * @notice Initializes the UsingRegistryUpgradable contract in an upgradable scenario
     * @param _registry The address of the Registry. For convenience, if the zero address is
     * provided, the registry is set to the canonical Registry address, i.e. 0x0...ce10. This
     * parameter should only be a non-zero address when testing.
     */
    // solhint-disable-next-line func-name-mixedcase
    function __UsingRegistry_init(address _registry) internal onlyInitializing {
        if (_registry == address(0)) {
            registry = IRegistry(CANONICAL_REGISTRY);
        } else {
            registry = IRegistry(_registry);
        }
    }

    /**
     * @notice Gets the Accounts contract from the Registry.
     * @return The Accounts contract from the Registry.
     */
    function getAccounts() internal view returns (IAccounts) {
        return IAccounts(registry.getAddressForOrDie(ACCOUNTS_REGISTRY_ID));
    }

    /**
     * @notice Gets the Election contract from the Registry.
     * @return The Election contract from the Registry.
     */
    function getElection() internal view returns (IElection) {
        return IElection(registry.getAddressForOrDie(ELECTION_REGISTRY_ID));
    }

    /**
     * @notice Gets the GoldToken contract from the Registry.
     * @return The GoldToken contract from the Registry.
     */
    function getGoldToken() internal view returns (IGoldToken) {
        return IGoldToken(registry.getAddressForOrDie(GOLD_TOKEN_REGISTRY_ID));
    }

    /**
     * @notice Gets the LockedGold contract from the Registry.
     * @return The LockedGold contract from the Registry.
     */
    function getLockedGold() internal view returns (ILockedGold) {
        return ILockedGold(registry.getAddressForOrDie(LOCKED_GOLD_REGISTRY_ID));
    }

    /**
     * @notice Gets the Governance contract from the Registry.
     * @return The Governance contract from the Registry.
     */
    function getGovernance() internal view returns (IGovernance) {
        return IGovernance(registry.getAddressForOrDie(GOVERNANCE_REGISTRY_ID));
    }

    /**
     * @notice Gets the validators contract from the Registry.
     * @return The validators contract from the Registry.
     */
    function getValidators() internal view returns (IValidators) {
        return IValidators(registry.getAddressForOrDie(VALIDATORS_REGISTRY_ID));
    }
}
          

// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity 0.8.11;

interface ISpecificGroupStrategy {
    function generateDepositVoteDistribution(
        address group,
        uint256 votes,
        uint256 stCeloAmount
    ) external returns (address[] memory finalGroups, uint256[] memory finalVotes);

    function generateWithdrawalVoteDistribution(
        address group,
        uint256 celoWithdrawalAmount,
        uint256 stCeloWithdrawalAmount,
        bool isTransfer
    ) external returns (address[] memory groups, uint256[] memory votes);

    function isVotedGroup(address group) external view returns (bool);

    function isBlockedGroup(address group) external view returns (bool);

    function getStCeloInGroup(address group)
        external
        view
        returns (
            uint256 total,
            uint256 overflow,
            uint256 unhealthy
        );

    function totalStCeloLocked() external view returns (uint256);

    function totalStCeloOverflow() external view returns (uint256);

    function getNumberOfVotedGroups() external view returns (uint256);
}
          

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

pragma solidity ^0.8.0;

/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeacon {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}
          

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

pragma solidity ^0.8.0;

import "../ERC1967/ERC1967Upgrade.sol";

/**
 * @dev An upgradeability mechanism designed for UUPS proxies. The functions included here can perform an upgrade of an
 * {ERC1967Proxy}, when this contract is set as the implementation behind such a proxy.
 *
 * A security mechanism ensures that an upgrade does not turn off upgradeability accidentally, although this risk is
 * reinstated if the upgrade retains upgradeability but removes the security mechanism, e.g. by replacing
 * `UUPSUpgradeable` with a custom implementation of upgrades.
 *
 * The {_authorizeUpgrade} function must be overridden to include access restriction to the upgrade mechanism.
 *
 * _Available since v4.1._
 */
abstract contract UUPSUpgradeable is ERC1967Upgrade {
    /// @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
    address private immutable __self = address(this);

    /**
     * @dev Check that the execution is being performed through a delegatecall call and that the execution context is
     * a proxy contract with an implementation (as defined in ERC1967) pointing to self. This should only be the case
     * for UUPS and transparent proxies that are using the current contract as their implementation. Execution of a
     * function through ERC1167 minimal proxies (clones) would not normally pass this test, but is not guaranteed to
     * fail.
     */
    modifier onlyProxy() {
        require(address(this) != __self, "Function must be called through delegatecall");
        require(_getImplementation() == __self, "Function must be called through active proxy");
        _;
    }

    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeTo(address newImplementation) external virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, new bytes(0), false);
    }

    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`, and subsequently execute the function call
     * encoded in `data`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, data, true);
    }

    /**
     * @dev Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
     * {upgradeTo} and {upgradeToAndCall}.
     *
     * Normally, this function will use an xref:access.adoc[access control] modifier such as {Ownable-onlyOwner}.
     *
     * ```solidity
     * function _authorizeUpgrade(address) internal override onlyOwner {}
     * ```
     */
    function _authorizeUpgrade(address newImplementation) internal virtual;
}
          

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

pragma solidity ^0.8.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            if (lastIndex != toDeleteIndex) {
                bytes32 lastvalue = set._values[lastIndex];

                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastvalue;
                // Update the index for the moved value
                set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        return _values(set._inner);
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        assembly {
            result := store
        }

        return result;
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        assembly {
            result := store
        }

        return result;
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/ERC1967/ERC1967Upgrade.sol)

pragma solidity ^0.8.2;

import "../beacon/IBeacon.sol";
import "../../utils/Address.sol";
import "../../utils/StorageSlot.sol";

/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 * @custom:oz-upgrades-unsafe-allow delegatecall
 */
abstract contract ERC1967Upgrade {
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;

    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }

    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        _upgradeTo(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }
    }

    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallSecure(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        address oldImplementation = _getImplementation();

        // Initial upgrade and setup call
        _setImplementation(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }

        // Perform rollback test if not already in progress
        StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
        if (!rollbackTesting.value) {
            // Trigger rollback using upgradeTo from the new implementation
            rollbackTesting.value = true;
            Address.functionDelegateCall(
                newImplementation,
                abi.encodeWithSignature("upgradeTo(address)", oldImplementation)
            );
            rollbackTesting.value = false;
            // Check rollback was effective
            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
            // Finally reset to the new implementation and log the upgrade
            _upgradeTo(newImplementation);
        }
    }

    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);

    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;

    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);

    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
    }

    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            Address.isContract(IBeacon(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }

    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(
        address newBeacon,
        bytes memory data,
        bool forceCall
    ) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
        }
    }
}
          

// 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);
            }
        }
    }
}
          

// 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;
}
          

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

pragma solidity ^0.8.0;

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

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal onlyInitializing {
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }

    /**
     * @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;
}
          

// 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));
    }
}