Contract Address Details

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

import {IERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import {SafeERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import {MathUpgradeable} from "@openzeppelin/contracts-upgradeable/utils/math/MathUpgradeable.sol";
import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import {ReentrancyGuardUpgradeable} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";

import {IVestedFX} from "./interfaces/IVestedFX.sol";
import {IRewardDistributor} from "./interfaces/IRewardDistributor.sol";
import {IWFX} from "./interfaces/IWFX.sol";
import {BaseVault} from "./vaults/BaseVault.sol";
import {PrecompileStaking} from "./imp/PrecompileStaking.sol";

contract StakeFXVaultV3 is
    Initializable,
    UUPSUpgradeable,
    PrecompileStaking,
    ReentrancyGuardUpgradeable,
    BaseVault
{
    using SafeERC20Upgradeable for IERC20Upgradeable;
    using MathUpgradeable for uint256;

    uint256 internal constant BIPS_DIVISOR = 10000;
    uint256 internal constant PRECISION = 1e30;
    address constant WFX = 0x80b5a32E4F032B2a058b4F29EC95EEfEEB87aDcd;  // WFX mainnet: 0x80b5a32E4F032B2a058b4F29EC95EEfEEB87aDcd; WFX testnet: 0x3452e23F9c4cC62c70B7ADAd699B264AF3549C19

    uint256 public pendingFxReward;             // FX delegation rewards inside the contract pending for compound
    uint256 public feeOnReward;                 // Compound reward protocol fee
    uint256 public feeOnCompounder;             // Compound reward compounder fee
    uint256 public feeOnWithdrawal;             // Withdrawal fee
    address public vestedFX;                    // Contract that stored user's withdrawal info
    address public feeTreasury;                 // Contract that keep compound reward fee
    address public distributor;                 // Reward token distributor

    uint256 private MIN_COMPOUND_AMOUNT;        // Minimum reward amount to compound when stake happen
    uint256 private CAP_STAKE_FX_TARGET;        // Cap amount of stFX
    uint256 private STAKE_FX_TARGET;            // Target stake amount to do whole validator list delegate(Deprecated)
    uint256 private UNSTAKE_FX_TARGET;          // Target unstake amount to split undelegate(Deprecated)
    
    VaultInfo public vaultInfo;                     // Vault Info
    mapping(uint256 => ValInfo) public valInfo;     // Validator info
    mapping(address => UserInfo) public userInfo;   // User info
    mapping(string => bool) public addedValidator;  // True if validator is added

    struct VaultInfo {
        uint256 stakeId;
        uint256 unstakeId;
        uint256 length;
        uint256 totalAllocPoint;
        uint256 cumulativeRewardPerToken;
    }

    struct ValInfo {
        uint256 allocPoint;
        string validator;
    }

    struct UserInfo {
        uint256 claimableReward;
        uint256 previousCumulatedRewardPerToken;
    }

    event Stake(address indexed user, uint256 amount, uint256 shares);
    event Unstake(address indexed user, uint256 amount, uint256 shares);
    event Compound(address indexed user, uint256 compoundAmount);
    event Claim(address receiver, uint256 amount);
    event ValidatorAdded(string val, uint256 newAllocPoint);
    event ValidatorRemoved(string val);
    event ValidatorUpdated(string val, uint256 newAllocPoint);
    event VestedFXChanged(address newAddress);
    event FeeTreasuryChanged(address newAddress);
    event DistributorChanged(address newAddress);
    event ValidatorRedelegated(string srcVal, string dstVal, uint256 sharesAmount, uint256 redelegatedShares); // last 2 arguments changed to FxAmount in staking V2

    receive() external payable {}

    modifier onlyVestedFX() {
        require(msg.sender == vestedFX, "Only VestedFX can call");
        _;
    }

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    /****************************************** Core External Functions ******************************************/
    /**
     * @notice user stake FX/WFX to this contract
     * @param amount stake amount
     * @param native stake FX or WFX token
     */
    function stake(uint256 amount, bool native) external payable nonReentrant whenNotPaused {
        require(amount > 0, "Stake: 0 amount");
        require(msg.value == (native == true ? amount : 0), "!valid");
        require(amount + totalAssets() <= CAP_STAKE_FX_TARGET, "Stake: > Cap");

        // Skip check delegation reward to save gas
        _compound();
        _claim(msg.sender, msg.sender);
        
        if(native == false) {
            IWFX(WFX).transferFrom(msg.sender, address(this), amount); 
            IWFX(WFX).withdraw(payable(address(this)), amount);
        }

        uint256 shares = previewDeposit(amount);
        _mint(msg.sender, shares);

        _stake(amount);

        emit Stake(msg.sender, amount, shares);
    }

    /**
     * @notice user unstake(request undelegate FX)
     * @param amount User's fx-LP receipt tokens
     */
    function unstake(uint256 amount) external nonReentrant whenNotPaused {
        require(amount > 0, "Unstake: 0 amount");
        uint256 sharesBalance = balanceOf(msg.sender);
        require(sharesBalance >= amount, "Amount > stake");

        _compound();
        _claim(msg.sender, msg.sender);

        uint256 undelegateAmount = previewRedeem(amount);
        uint256 undelegateAmountAfterFee = undelegateAmount * (BIPS_DIVISOR - feeOnWithdrawal) / BIPS_DIVISOR;

        _burn(msg.sender, amount);
        if (undelegateAmountAfterFee > 0) {
            _unstake(undelegateAmountAfterFee);
        }
     
        emit Unstake(msg.sender, undelegateAmountAfterFee, amount);
    }

    /**
     * @notice transfer user delegation shares to this contract
     * @param val validator address
     * @param amount Amount of user's delegate shares transferred to this contract
     */
    function entrustDelegatedShare(string memory val, uint256 amount) external nonReentrant whenNotPaused {
        require(amount > 0, "Entrust: 0 share");

        (uint256 sharesAmount, uint256 delegationAmount) = _delegation(val, msg.sender);
        require(sharesAmount >= amount, "Not enough share");

        _compound();
        _claim(msg.sender, msg.sender);
        
        uint256 totalAsset = totalAssets();
        uint256 estimateDelegateAmount = amount / sharesAmount * delegationAmount;
        require(estimateDelegateAmount + totalAsset <= CAP_STAKE_FX_TARGET, "Stake: > Cap");

        uint256 supply = totalSupply();
        (uint256 fxAmountToTransfer, uint256 returnReward) = _transferFromShares(val, msg.sender, address(this), amount);

        pendingFxReward += returnReward;

        uint256 shares = (fxAmountToTransfer == 0 || supply == 0)
                ? _initialConvertToShares(fxAmountToTransfer, MathUpgradeable.Rounding.Down)
                : fxAmountToTransfer.mulDiv(supply, totalAsset, MathUpgradeable.Rounding.Down);

        _mint(msg.sender, shares);

        emit Stake(msg.sender, fxAmountToTransfer, shares); 
    }

    function claim(address receiver) external nonReentrant returns (uint256) {
        return _claim(msg.sender, receiver);
    }

    /**
     * @notice compound delegation rewards
     */
    function compound() external nonReentrant whenNotPaused {
        _compound();
    }

    function updateRewards() external nonReentrant {
        _updateRewards(address(0));
    }

    function sendVestedFX(
        uint256 safeAmount
    ) external onlyVestedFX {
        address recipient = payable(msg.sender);
        (bool success, ) = recipient.call{value: safeAmount}("");
        require(success, "Failed to send FX");
    }

    /**************************************** Internal and Private Functions ****************************************/
    /**
    * @dev Helper function to delegate FX amount to validators.
    * @param  amount  The amount: FX delegate to validators.
    */
    function _stake(uint256 amount) internal {
        VaultInfo memory vault = vaultInfo;
        uint256 totalAllocPoint = vault.totalAllocPoint;
        uint256 index = vault.stakeId;

        uint256 valLength = getValLength();
        uint256 _totalAssets = totalAssets();
        uint256 numValidators = _calculateNumberofValidators(amount);
        uint256 amountPerValidator = amount / numValidators;
        uint256 remainingAmount = amount;
        uint256 delegateAmount;

        while (remainingAmount != 0) {
            ValInfo memory val = valInfo[index];
            uint256 allocPoint = val.allocPoint;
            index = (index + 1) % valLength;

            if (allocPoint == 0) {
                continue;
            }
            
            if (_totalAssets >= CAP_STAKE_FX_TARGET) {
                delegateAmount = remainingAmount;
            } else {
                (, uint256 delegationAmount) = _delegation(val.validator, address(this));
                uint256 maxValSize = allocPoint * CAP_STAKE_FX_TARGET / totalAllocPoint;

                if (delegationAmount >= maxValSize) {
                    continue;
                }

                if (remainingAmount <= amountPerValidator) {
                    delegateAmount = remainingAmount;
                } else {
                    delegateAmount = amountPerValidator;
                }
            }

            bool result = _delegateV2(val.validator, delegateAmount);
            require(result == true, "delegate fail");
            _totalAssets += delegateAmount;
            remainingAmount -= delegateAmount;
        }

        vaultInfo.stakeId = index;
    }

    /**
    * @dev Helper function to undelegate FX amount from validators.
    * @param  amount  The amount: FX to unstake from the vault.
    */
    function _unstake(uint256 amount) internal {
        VaultInfo memory vault = vaultInfo;
        uint256 index = vault.unstakeId;
        uint256 valLength = getValLength();

        uint256 remainingAmount = amount;
        uint256 totalReward;        
        uint256 returnUndelegatedAmount;
        uint256 returnReward;
         
        // If contract byte size exceed limit, divide to half part can be removed
        if (amount >= UNSTAKE_FX_TARGET) {
            uint256 halfOfUndelegateAmount = amount / 2; 
            (returnUndelegatedAmount) = _toUndelegate(index, halfOfUndelegateAmount);
                
            remainingAmount -= returnUndelegatedAmount;
            index = (index + 1) % valLength;
            totalReward += returnReward;
        }

        while (remainingAmount != 0) {
            (returnUndelegatedAmount) = _toUndelegate(index, remainingAmount);
            
            remainingAmount -= returnUndelegatedAmount;
            index = (index + 1) % valLength;
            totalReward += returnReward;
        }

        IVestedFX(vestedFX).lockWithEndTime(
            msg.sender,            
            amount,
            block.timestamp + 21 days
        );

        vaultInfo.unstakeId = index;
        pendingFxReward += totalReward;
    }

    /**
    * @dev Helper function to undelegate FX amount from validators.
    * @param  index Validator ID in validator list.
    * @param  remainingAmount Amount to undelegate from validators.
    */
    function _toUndelegate(uint256 index, uint256 remainingAmount) internal returns(uint256) {
        (, uint256 delegationAmount) = _delegation(valInfo[index].validator, address(this));

        uint256 amountToUndelegate;

        if (delegationAmount > 0) {
            if (delegationAmount >= remainingAmount) {
                amountToUndelegate = remainingAmount;
            } else {
                amountToUndelegate = delegationAmount;
            }

            bool result = _undelegateV2(valInfo[index].validator, amountToUndelegate);
            require(result == true, "delegate fail");
        }

        return amountToUndelegate;
    }

    /**
    * @dev Helper function to compound FX amount from validators.
    */
    function _compound() internal {
        _withdrawReward();
        uint256 delegateReward = pendingFxReward;
        pendingFxReward = 0;

        uint256 feeProtocol = (delegateReward * feeOnReward) / BIPS_DIVISOR;
        uint256 feeCompounder = (delegateReward * feeOnCompounder) / BIPS_DIVISOR;

        delegateReward = delegateReward - feeProtocol - feeCompounder;
        _stake(delegateReward);

        address treasury = payable(feeTreasury);
        address user = payable(msg.sender);
        (bool successTreasury, ) = treasury.call{value: feeProtocol}("");
        (bool successUser, ) = user.call{value: feeCompounder}("");
        require(successTreasury && successUser, "Failed to send FX");

        emit Compound(msg.sender, delegateReward);
    }

    /**
    * @dev Helper function to withdraw delegation fx rewards from all validators.
    */
    function _withdrawReward() internal {
        uint256 reward = 0;
        uint256 valLength = getValLength();

        for (uint256 i; i < valLength; i++) {
            string memory validator = valInfo[i].validator;
            uint256 delegationReward = _delegationRewards(validator, address(this));
            if(delegationReward > 0) {
                uint256 returnReward = _withdraw(validator);
                reward += returnReward;
            }
        }

        pendingFxReward += reward;
    }

    /**
    * @dev Helper function to help to calculate number of validator to delegate based on Log10 input amount.
    * @param delegateAmount Fx Amount to stake.
    * @return Number of validators to delegate.
    */
    function _calculateNumberofValidators(
        uint256 delegateAmount
    ) internal view returns (uint256) {
        uint256 numValidators;
        uint256 delegateAmountInEther = delegateAmount / 10**18;

        uint256 valLength = getValLength();
        while (delegateAmountInEther >= 10) {
            delegateAmountInEther /= 10;
            numValidators++;
        }

        return (numValidators == 0) ? 1 : (numValidators > valLength
                ? valLength
                : numValidators);
    }

    /**
    * @dev Helper function to help to query total FX delegation.
    */
    function _getUnderlyingFX() internal view returns (uint256) {
        uint256 totalAmount;
        uint256 valLength = getValLength();
        for (uint256 i; i < valLength; i++) {
            string memory validator = valInfo[i].validator;
            (, uint256 delegationAmount) = _delegation(validator, address(this));
            totalAmount += delegationAmount;
        }
        return totalAmount;
    }

    function _claim(address account, address receiver) private returns (uint256) {
        _updateRewards(account);
        UserInfo storage user = userInfo[account];
        uint256 tokenAmount = user.claimableReward;
        user.claimableReward = 0;

        if (tokenAmount > 0) {
            IERC20Upgradeable(rewardToken()).safeTransfer(receiver, tokenAmount);
            emit Claim(account, tokenAmount);
        }

        return tokenAmount;
    }

    function _updateRewards(address account) private {
        uint256 blockReward = IRewardDistributor(distributor).distribute();

        uint256 supply = totalSupply();
        uint256 _cumulativeRewardPerToken = vaultInfo.cumulativeRewardPerToken;
        if (supply > 0 && blockReward > 0) {
            _cumulativeRewardPerToken = _cumulativeRewardPerToken + (blockReward * (PRECISION) / (supply));
            vaultInfo.cumulativeRewardPerToken = _cumulativeRewardPerToken;
        }

        // cumulativeRewardPerToken can only increase
        // so if cumulativeRewardPerToken is zero, it means there are no rewards yet
        if (_cumulativeRewardPerToken == 0) {
            return;
        }

        if (account != address(0)) {
            UserInfo storage user = userInfo[account];
            uint256 stakedAmount = balanceOf(account);
            uint256 accountReward = stakedAmount * (_cumulativeRewardPerToken - (user.previousCumulatedRewardPerToken)) / (PRECISION);
            uint256 _claimableReward = user.claimableReward + (accountReward);

            user.claimableReward = _claimableReward;
            user.previousCumulatedRewardPerToken = _cumulativeRewardPerToken;
        }
    }

    function _beforeTokenTransfer(address from, address to, uint256 amount)
        internal
        whenNotPaused
        override
    {
        _updateRewards(from);
        _updateRewards(to);

        super._beforeTokenTransfer(from, to, amount);
    }

    function _authorizeUpgrade(
        address
    ) internal override onlyRole(OWNER_ROLE) {} 


    /**************************************** Public/External View Functions ****************************************/

    /**
     * @notice Return total asset(FX) deposited
     * @return Amount of asset(FX) deposited
     */
    function totalAssets() public view override returns (uint256) {
        uint256 underlying = _getUnderlyingFX();
        return underlying;
    }

    function getValLength() public view returns (uint256) {
        return vaultInfo.length;
    }

    /**
     * @notice Return validator address and allocPoint
     */
    function getValInfo(uint256 index) public view returns (uint256, string memory) {
        return (valInfo[index].allocPoint, valInfo[index].validator);
    }

    /**
     * @notice Return total delegation reward
     */
    function getTotalDelegationRewards() public view returns (uint256) {
        uint256 totalAmount;
        uint256 valLength = getValLength();
        for (uint256 i; i < valLength; i++) {
            string memory validator = valInfo[i].validator;
            uint256 delegationReward = _delegationRewards(validator, address(this));
            totalAmount += delegationReward;
        }
        return totalAmount + pendingFxReward;
    }

    /**
     * @notice Return vault config(remove STAKE_FX_TARGET)
     */
    function getVaultConfigs() public view returns (uint256, uint256, uint256) {
        return (MIN_COMPOUND_AMOUNT, CAP_STAKE_FX_TARGET, UNSTAKE_FX_TARGET);
    }

    function rewardToken() public view returns (address) {
        return IRewardDistributor(distributor).rewardToken();
    }

    function claimable(address account) public view returns (uint256) {
        UserInfo memory user = userInfo[account];
        uint256 stakedAmount = balanceOf(account);
        if (stakedAmount == 0) {
            return user.claimableReward;
        }
        uint256 supply = totalSupply();
        uint256 pendingRewards = IRewardDistributor(distributor).pendingRewards() * (PRECISION);
        uint256 nextCumulativeRewardPerToken = vaultInfo.cumulativeRewardPerToken + (pendingRewards / (supply));
        return user.claimableReward + (
            stakedAmount * (nextCumulativeRewardPerToken - (user.previousCumulatedRewardPerToken)) / (PRECISION));
    }

    /**************************************** Only Governor Functions ****************************************/

    function redelegateValidator(
        uint256 srcId,
        uint256 dstId,
        uint256 redelegateAmount
    ) external onlyRole(GOVERNOR_ROLE) {
        require(srcId < vaultInfo.length && dstId < vaultInfo.length, "Invalid ID");
        ValInfo memory srcVal = valInfo[srcId];
        ValInfo memory dstVal = valInfo[dstId];
        (, uint256 delegationAmount) = _delegation(srcVal.validator, address(this));
        require(redelegateAmount <= delegationAmount, "!Amount");

        _compound();
        bool result = _redelegateV2(srcVal.validator, dstVal.validator, redelegateAmount);
        require(result == true, "delegate fail");

        emit ValidatorRedelegated(srcVal.validator, dstVal.validator, redelegateAmount, redelegateAmount);
    }

    function addValidator(
        string memory _validator,
        uint256 _allocPoint
    ) external onlyRole(GOVERNOR_ROLE) {
        require(addedValidator[_validator] == false, "addedVal");
        valInfo[vaultInfo.length].validator = _validator;
        valInfo[vaultInfo.length].allocPoint = _allocPoint;

        vaultInfo.length++;
        vaultInfo.totalAllocPoint += _allocPoint;

        addedValidator[_validator]=true;

        emit ValidatorAdded(_validator, _allocPoint);
    }

    /**
     * @notice remove validators which has 0 allocPoint and 0 delegation in the list 
     */
    function removeValidator() external onlyRole(GOVERNOR_ROLE) {
        uint256 valLength = getValLength();

        for (uint256 i = 0; i < valLength;) {
            if (valInfo[i].allocPoint == 0) {
                string memory val = valInfo[i].validator;
                (uint256 sharesAmount, ) = _delegation(val, address(this));

                if (sharesAmount == 0) {
                    addedValidator[val] = false;
                    uint256 lastIndex = valLength - 1;
                    valInfo[i] = valInfo[lastIndex];
                    delete valInfo[lastIndex];

                    emit ValidatorRemoved(val);
                    valLength--;
                    // Skip if i == 0 to prevent underflow
                    if (i == 0) {
                        continue;
                    } else {
                        --i;
                    }
                }
            }
            unchecked {
                ++i;
            }
        }
        // Reset stakeID, unstakeID, validator length
        vaultInfo.stakeId = 0;
        vaultInfo.unstakeId = 0;
        vaultInfo.length = valLength;
    }

    function updateValidator(
        uint256 id,
        uint256 newAllocPoint
    ) external onlyRole(GOVERNOR_ROLE) {
        require(id < vaultInfo.length, "Invalid ID");
        uint256 oldAllocPoint = valInfo[id].allocPoint;

        vaultInfo.totalAllocPoint = vaultInfo.totalAllocPoint + newAllocPoint - oldAllocPoint;
        valInfo[id].allocPoint = newAllocPoint;

        emit ValidatorUpdated(valInfo[id].validator, newAllocPoint);
    }

    /**
     * @notice Update vault config(remove STAKE_FX_TARGET)
     */
    function updateConfigs(uint256 newMinCompound, uint256 newCapStakeFxTarget, uint256 newUnstakeFxTarget) external onlyRole(GOVERNOR_ROLE) {
        MIN_COMPOUND_AMOUNT = newMinCompound;
        CAP_STAKE_FX_TARGET = newCapStakeFxTarget;
        UNSTAKE_FX_TARGET = newUnstakeFxTarget;
    }

    /**
     * @notice Update compounding fee percentage for protocol and compounder and user withdrawal percentage
     * require(newFeeOnReward + newFeeOnCompounder) <= BIPS_DIVISOR && newFeeOnWithdrawal <= BIPS_DIVISOR)
     */
    function updateFees(uint256 newFeeOnReward, uint256 newFeeOnCompounder, uint256 newFeeOnWithdrawal) external onlyRole(GOVERNOR_ROLE) {
        feeOnReward = newFeeOnReward;
        feeOnCompounder = newFeeOnCompounder;
        feeOnWithdrawal = newFeeOnWithdrawal;
    }

    /**************************************** Only Owner Functions ****************************************/

    function updateVestedFX(address newAddress) external onlyRole(OWNER_ROLE) {
        vestedFX = newAddress;
        emit VestedFXChanged(newAddress);
    }

    function updateFeeTreasury(address newAddress) external onlyRole(OWNER_ROLE) {
        feeTreasury = newAddress;
        emit FeeTreasuryChanged(newAddress);
    }
    
    function updateDistributor(address newAddress) external onlyRole(OWNER_ROLE) {
        distributor = newAddress;
        emit DistributorChanged(newAddress);
    }

    function recoverToken(
        address token,
        uint256 amount,
        address _recipient
    ) external onlyRole(OWNER_ROLE) {
        require(_recipient != address(0), "Send to zero address");
        if(token != address(0)) {
            IERC20Upgradeable(token).safeTransfer(_recipient, amount);
        } else {
            address recipient = payable(_recipient);
            (bool success, ) = recipient.call{value: amount}("");
            require(success, "Failed to send FX");
        }
    }

    /**************************************************************
     * @dev Initialize the states
     *************************************************************/

    function initialize(
        address _asset,
        address _owner,
        address _governor
    ) public initializer {
        __BaseVaultInit(
            _asset,
            "Staked FX Token",
            "StFX",
            _owner,
            _governor
        );
        // __Governable_init(_owner, _governor);    redundant code
        __UUPSUpgradeable_init();
    }
}
        

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard signed math utilities missing in the Solidity language.
 */
library SignedMathUpgradeable {
    /**
     * @dev Returns the largest of two signed numbers.
     */
    function max(int256 a, int256 b) internal pure returns (int256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two signed numbers.
     */
    function min(int256 a, int256 b) internal pure returns (int256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two signed numbers without overflow.
     * The result is rounded towards zero.
     */
    function average(int256 a, int256 b) internal pure returns (int256) {
        // Formula from the book "Hacker's Delight"
        int256 x = (a & b) + ((a ^ b) >> 1);
        return x + (int256(uint256(x) >> 255) & (a ^ b));
    }

    /**
     * @dev Returns the absolute unsigned value of a signed value.
     */
    function abs(int256 n) internal pure returns (uint256) {
        unchecked {
            // must be unchecked in order to support `n = type(int256).min`
            return uint256(n >= 0 ? n : -n);
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (proxy/ERC1967/ERC1967Upgrade.sol)

pragma solidity ^0.8.2;

import "../beacon/IBeaconUpgradeable.sol";
import "../../interfaces/IERC1967Upgradeable.sol";
import "../../interfaces/draft-IERC1822Upgradeable.sol";
import "../../utils/AddressUpgradeable.sol";
import "../../utils/StorageSlotUpgradeable.sol";
import "../utils/Initializable.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._
 */
abstract contract ERC1967UpgradeUpgradeable is Initializable, IERC1967Upgradeable {
    function __ERC1967Upgrade_init() internal onlyInitializing {
    }

    function __ERC1967Upgrade_init_unchained() internal onlyInitializing {
    }
    // 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 Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(AddressUpgradeable.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlotUpgradeable.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) {
            AddressUpgradeable.functionDelegateCall(newImplementation, data);
        }
    }

    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallUUPS(address newImplementation, bytes memory data, bool forceCall) internal {
        // Upgrades from old implementations will perform a rollback test. This test requires the new
        // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
        // this special case will break upgrade paths from old UUPS implementation to new ones.
        if (StorageSlotUpgradeable.getBooleanSlot(_ROLLBACK_SLOT).value) {
            _setImplementation(newImplementation);
        } else {
            try IERC1822ProxiableUpgradeable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
            } catch {
                revert("ERC1967Upgrade: new implementation is not UUPS");
            }
            _upgradeToAndCall(newImplementation, data, forceCall);
        }
    }

    /**
     * @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 Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlotUpgradeable.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");
        StorageSlotUpgradeable.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 Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value;
    }

    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(AddressUpgradeable.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            AddressUpgradeable.isContract(IBeaconUpgradeable(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlotUpgradeable.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) {
            AddressUpgradeable.functionDelegateCall(IBeaconUpgradeable(newBeacon).implementation(), 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 (last updated v4.9.0) (proxy/utils/UUPSUpgradeable.sol)

pragma solidity ^0.8.0;

import "../../interfaces/draft-IERC1822Upgradeable.sol";
import "../ERC1967/ERC1967UpgradeUpgradeable.sol";
import "./Initializable.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 Initializable, IERC1822ProxiableUpgradeable, ERC1967UpgradeUpgradeable {
    function __UUPSUpgradeable_init() internal onlyInitializing {
    }

    function __UUPSUpgradeable_init_unchained() internal onlyInitializing {
    }
    /// @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 Check that the execution is not being performed through a delegate call. This allows a function to be
     * callable on the implementing contract but not through proxies.
     */
    modifier notDelegated() {
        require(address(this) == __self, "UUPSUpgradeable: must not be called through delegatecall");
        _;
    }

    /**
     * @dev Implementation of the ERC1822 {proxiableUUID} function. This returns the storage slot used by the
     * implementation. It is used to validate the implementation's compatibility when performing an upgrade.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy. This is guaranteed by the `notDelegated` modifier.
     */
    function proxiableUUID() external view virtual override notDelegated returns (bytes32) {
        return _IMPLEMENTATION_SLOT;
    }

    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     *
     * @custom:oz-upgrades-unsafe-allow-reachable delegatecall
     */
    function upgradeTo(address newImplementation) public virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallUUPS(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.
     *
     * @custom:oz-upgrades-unsafe-allow-reachable delegatecall
     */
    function upgradeToAndCall(address newImplementation, bytes memory data) public payable virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallUUPS(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;

    /**
     * @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 (last updated v4.9.0) (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
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [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://consensys.net/diligence/blog/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/v0.8.0/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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}
          

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

interface IMintable {
    function mint(address _account, uint256 _amount) external;
    
    function burn(uint256 _amount) external;
}
          

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

import {IERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import {SafeERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import {MathUpgradeable} from "@openzeppelin/contracts-upgradeable/utils/math/MathUpgradeable.sol";
import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import {ReentrancyGuardUpgradeable} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";

import {IVestedFX} from "./interfaces/IVestedFX.sol";
import {IRewardDistributor} from "./interfaces/IRewardDistributor.sol";
import {IWFX} from "./interfaces/IWFX.sol";
import {BaseVault} from "./vaults/BaseVault.sol";
import {PrecompileStaking} from "./imp/PrecompileStaking.sol";

contract StakeFXVault is
    Initializable,
    UUPSUpgradeable,
    PrecompileStaking,
    ReentrancyGuardUpgradeable,
    BaseVault
{
    using SafeERC20Upgradeable for IERC20Upgradeable;
    using MathUpgradeable for uint256;

    uint256 internal constant BIPS_DIVISOR = 10000;
    uint256 internal constant PRECISION = 1e30;
    address constant WFX = 0x80b5a32E4F032B2a058b4F29EC95EEfEEB87aDcd;  // WFX mainnet: 0x80b5a32E4F032B2a058b4F29EC95EEfEEB87aDcd; WFX testnet: 0x3452e23F9c4cC62c70B7ADAd699B264AF3549C19

    uint256 public pendingFxReward;             // FX delegation rewards inside the contract pending for compound
    uint256 public feeOnReward;                 // Compound reward protocol fee
    uint256 public feeOnCompounder;             // Compound reward compounder fee
    uint256 public feeOnWithdrawal;             // Withdrawal fee
    address public vestedFX;                    // Contract that stored user's withdrawal info
    address public feeTreasury;                 // Contract that keep compound reward fee
    address public distributor;                 // Reward token distributor

    uint256 private MIN_COMPOUND_AMOUNT;        // Minimum reward amount to compound when stake happen
    uint256 private CAP_STAKE_FX_TARGET;        // Cap amount of stFX
    uint256 private STAKE_FX_TARGET;            // Target stake amount to do whole validator list delegate
    uint256 private UNSTAKE_FX_TARGET;          // Target unstake amount to split undelegate
    
    VaultInfo public vaultInfo;                     // Vault Info
    mapping(uint256 => ValInfo) public valInfo;     // Validator info
    mapping(address => UserInfo) public userInfo;   // User info
    mapping(string => bool) public addedValidator;  // True if validator is added

    struct VaultInfo {
        uint256 stakeId;
        uint256 unstakeId;
        uint256 length;        
        uint256 totalAllocPoint;
        uint256 cumulativeRewardPerToken;
    }

    struct ValInfo {
        uint256 allocPoint;
        string validator;
    }

    struct UserInfo {
        uint256 claimableReward;
        uint256 previousCumulatedRewardPerToken;
    }

    event Stake(address indexed user, uint256 amount, uint256 shares);
    event Unstake(address indexed user, uint256 amount, uint256 shares);
    event Compound(address indexed user, uint256 compoundAmount);
    event Claim(address receiver, uint256 amount);
    event ValidatorAdded(string val, uint256 newAllocPoint);
    event ValidatorRemoved(string val);
    event ValidatorUpdated(string val, uint256 newAllocPoint);
    event VestedFXChanged(address newAddress);
    event FeeTreasuryChanged(address newAddress);
    event DistributorChanged(address newAddress);

    receive() external payable {}

    modifier onlyVestedFX() {
        require(msg.sender == vestedFX, "Only VestedFX can call");
        _;
    }

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    /****************************************** Core External Functions ******************************************/
    /**
     * @notice user stake FX to this contract
     */
    function stake() external payable whenNotPaused {
        require(msg.value > 0, "Stake: 0 amount");
        uint256 totalAsset = totalAssets();
        require(msg.value + totalAsset <= CAP_STAKE_FX_TARGET, "Stake: > Cap");

        uint256 delegationReward = getTotalDelegationRewards();
        if(delegationReward >= MIN_COMPOUND_AMOUNT) {
            compound();
        }
        _claim(msg.sender, msg.sender);

        uint256 shares = previewDeposit(msg.value);
        _mint(msg.sender, shares);

        _stake(msg.value);

        emit Stake(msg.sender, msg.value, shares);
    }

    /**
     * @notice user stake WFX to this contract
     */
    function stakeWFX(uint256 amount) external whenNotPaused {
        require(amount > 0, "Stake: 0 amount");
        uint256 totalAsset = totalAssets();
        require(amount + totalAsset <= CAP_STAKE_FX_TARGET, "Stake: > Cap");

        uint256 delegationReward = getTotalDelegationRewards();
        if(delegationReward >= MIN_COMPOUND_AMOUNT) {
            compound();
        }
        _claim(msg.sender, msg.sender);

        IWFX(WFX).transferFrom(msg.sender, address(this), amount); 
        IWFX(WFX).withdraw(payable(address(this)), amount);

        uint256 shares = previewDeposit(amount);
        _mint(msg.sender, shares);

        _stake(amount);

        emit Stake(msg.sender, amount, shares);
    }

    /**
     * @notice user unstake/ request undelegate FX
     * @param amount User's fx-LP receipt tokens
     */
    function unstake(uint256 amount) external whenNotPaused {
        require(amount > 0, "Unstake: 0 amount");
        uint256 sharesBalance = balanceOf(msg.sender);
        require(sharesBalance >= amount, "Amount > stake");

        _claim(msg.sender, msg.sender);

        uint256 undelegateAmount = previewRedeem(amount);
        uint256 undelegateAmountAfterFee = undelegateAmount * (BIPS_DIVISOR - feeOnWithdrawal) / BIPS_DIVISOR;

        _burn(msg.sender, amount);
        if (undelegateAmountAfterFee > 0) {
            _unstake(undelegateAmountAfterFee);
        }
     
        emit Unstake(msg.sender, undelegateAmountAfterFee, amount);
    }

    /**
     * @notice transfer user delegation shares to this contract
     * @param val validator address
     * @param amount Amount of user's delegate shares transferred to this contract
     */
    function entrustDelegatedShare(string memory val, uint256 amount) external whenNotPaused {
        require(amount > 0, "Entrust: 0 share");

        (uint256 sharesAmount, uint256 delegationAmount) = _delegation(val, msg.sender);
        require(sharesAmount >= amount, "Not enough share");

        uint256 delegationReward = getTotalDelegationRewards();
        if(delegationReward >= MIN_COMPOUND_AMOUNT) {
            compound();
        }
        _claim(msg.sender, msg.sender);
        
        uint256 totalAsset = totalAssets();
        uint256 estimateDelegateAmount = amount / sharesAmount * delegationAmount;
        require(estimateDelegateAmount + totalAsset <= CAP_STAKE_FX_TARGET, "Stake: > Cap");

        uint256 supply = totalSupply();
        (uint256 fxAmountToTransfer, uint256 returnRewards) = _transferFromShares(val, msg.sender, address(this), amount);

        pendingFxReward += returnRewards;

        uint256 shares = (fxAmountToTransfer == 0 || supply == 0)
                ? _initialConvertToShares(fxAmountToTransfer, MathUpgradeable.Rounding.Down)
                : fxAmountToTransfer.mulDiv(supply, totalAsset, MathUpgradeable.Rounding.Down);

        _mint(msg.sender, shares);

        emit Stake(msg.sender, fxAmountToTransfer, shares); 
    }

    function claim(address receiver) external nonReentrant returns (uint256) {
        return _claim(msg.sender, receiver);
    }

    /**
     * @notice compound delegation rewards
     */
    function compound() public nonReentrant whenNotPaused {
        uint256 delegateReward = _withdrawReward() + pendingFxReward;
        pendingFxReward = 0;

        uint256 feeProtocol = (delegateReward * feeOnReward) / BIPS_DIVISOR;
        uint256 feeCompounder = (delegateReward * feeOnCompounder) / BIPS_DIVISOR;

        delegateReward = delegateReward - feeProtocol - feeCompounder;
        _stake(delegateReward);

        address treasury = payable(feeTreasury);
        address user = payable(msg.sender);
        (bool successTreasury, ) = treasury.call{value: feeProtocol}("");
        (bool successUser, ) = user.call{value: feeCompounder}("");
        require(successTreasury && successUser, "Failed to send FX");

        emit Compound(msg.sender, delegateReward);
    }

    function sendVestedFX(
        uint256 safeAmount
    ) external onlyVestedFX {
        address recipient = payable(msg.sender);
        (bool success, ) = recipient.call{value: safeAmount}("");
        require(success, "Failed to send FX");
    }

    function updateRewards() external nonReentrant {
        _updateRewards(address(0));
    }

    /**************************************** Internal and Private Functions ****************************************/

    /**
    * @dev Helper function to delegate FX amount to validators.
    * @param  amount  The amount: FX delegate to validators.
    */
    function _stake(uint256 amount) internal {
        VaultInfo memory vault = vaultInfo;
        uint256 totalAllocPoint = vault.totalAllocPoint;
        uint256 index = vault.stakeId;
        uint256 vaultLength = vault.length;
        uint256 totalReturnReward;
        uint256 _totalAssets = totalAssets();

        // After execute removeValidator, stakeId may equal or greater than vaultLength
        if (index >= vaultLength) {
            index = 0;
        }

        if (amount <= STAKE_FX_TARGET) {
            uint256 numValidators = _calculateNumberofValidators(amount);
            uint256 amountPerValidator = amount / numValidators;
            uint256 remainingAmount = amount;
            uint256 delegateAmount;
            
            while (remainingAmount != 0) {
                ValInfo memory val = valInfo[index];
                uint256 allocPoint = val.allocPoint;
                index = (index + 1) % vaultLength;

                if (allocPoint == 0) {
                    continue;
                }
                
                if (_totalAssets >= CAP_STAKE_FX_TARGET) {
                    delegateAmount = remainingAmount;
                } else {
                    (, uint256 delegationAmount) = _delegation(val.validator, address(this));
                    uint256 maxValSize = allocPoint * CAP_STAKE_FX_TARGET / totalAllocPoint;

                    if (delegationAmount >= maxValSize) {
                        continue;
                    }

                    if (remainingAmount <= amountPerValidator) {
                        delegateAmount = remainingAmount;
                    } else {
                        delegateAmount = amountPerValidator;
                    }
                }

                (, uint256 returnReward) = _delegate(val.validator, delegateAmount);
                _totalAssets += delegateAmount;
                totalReturnReward += returnReward;
                remainingAmount -= delegateAmount;
            }
        } else {
            uint256 remainingAmount = amount;
            uint256 delegateAmount;
            
            while (remainingAmount != 0) {
                ValInfo memory val = valInfo[index];
                uint256 allocPoint = val.allocPoint;
                
                index = (index + 1) % vaultLength;

                // Skip validators that has 0 allocPoint
                if (allocPoint == 0) {
                    continue;
                }

                if (_totalAssets >= CAP_STAKE_FX_TARGET) {
                    delegateAmount = remainingAmount;
                } else {
                    (, uint256 delegationAmount) = _delegation(val.validator, address(this));
                    uint256 maxValSize = allocPoint * CAP_STAKE_FX_TARGET / totalAllocPoint;
                    
                    // Skip validators that has reach max of its allocation FX delegation
                    if (delegationAmount >= maxValSize) {
                        continue;
                    }

                    // If remainingAmount more than allocDelegateAmount, only delegate allocDelegateAmount
                    uint256 allocDelegateAmount = amount * allocPoint / totalAllocPoint;

                    if (remainingAmount <= allocDelegateAmount) {
                        delegateAmount = remainingAmount;
                    } else {
                        delegateAmount = allocDelegateAmount;
                    }
                }
                
                (, uint256 returnReward) = _delegate(val.validator, delegateAmount);
                _totalAssets += delegateAmount;
                totalReturnReward += returnReward;
                remainingAmount -= delegateAmount;
            }
        }

        vaultInfo.stakeId = index;
        pendingFxReward += totalReturnReward;
    }
    
    /**
    * @dev Helper function to undelegate FX amount from validators.
    * @param  amount  The amount: FX to unstake from the vault.
    */
    function _unstake(uint256 amount) internal {
        VaultInfo memory vault = vaultInfo;
        uint256 index = vault.unstakeId;
        uint256 vaultLength = vault.length;

        uint256 remainingAmount = amount;
        uint256 totalReward;        
        uint256 returnUndelegatedAmount;
        uint256 returnReward;
        uint256 endTime;
        
        // After execute removeValidator, stakeId may equal or greater than vaultLength
        if (index >= vaultLength) {
            index = 0;
        }   

        if (amount >= UNSTAKE_FX_TARGET) {
            uint256 halfOfUndelegateAmount = amount / 2; 
            (returnUndelegatedAmount, returnReward, endTime) = _toUndelegate(index, halfOfUndelegateAmount);
                
            remainingAmount -= returnUndelegatedAmount;
            index = (index + 1) % vaultLength;
            totalReward += returnReward;
        }

        while (remainingAmount != 0) {
            (returnUndelegatedAmount, returnReward, endTime) = _toUndelegate(index, remainingAmount);
            
            remainingAmount -= returnUndelegatedAmount;
            index = (index + 1) % vaultLength;
            totalReward += returnReward;
        }

        IVestedFX(vestedFX).lockWithEndTime(
            msg.sender,            
            amount,
            endTime
        );

        vaultInfo.unstakeId = index;
        pendingFxReward += totalReward;
    }

    /**
    * @dev Helper function to undelegate FX amount from validators.
    * @param  index Validator ID in validator list.
    * @param  remainingAmount Amount to undelegate from validators.
    */
    function _toUndelegate(uint256 index, uint256 remainingAmount) internal returns(uint256, uint256, uint256) {
        (uint256 sharesAmount, uint256 delegationAmount) = _delegation(valInfo[index].validator, address(this));

        uint256 amountToUndelegate;
        uint256 returnReward;
        uint256 endTime;

        if (delegationAmount > 0) {
            if (delegationAmount >= remainingAmount) {
                amountToUndelegate = remainingAmount;
            } else {
                amountToUndelegate = delegationAmount;
            }

            uint256 shareToWithdraw = (sharesAmount * amountToUndelegate) / delegationAmount;
            if (shareToWithdraw > 0) {
                (amountToUndelegate, returnReward, endTime) = _undelegate(valInfo[index].validator, shareToWithdraw);
            }
        }

        return (amountToUndelegate, returnReward, endTime);
    }

    /**
    * @dev Helper function to withdraw delegation fx rewards from all validators.
    */
    function _withdrawReward() internal returns (uint256) {
        VaultInfo memory vault = vaultInfo;
        uint256 reward = 0;
        
        uint256 vaultLength = vault.length;

        for (uint256 i; i < vaultLength; i++) {
            string memory validator = valInfo[i].validator;
            uint256 delegationReward = _delegationRewards(validator, address(this));
            if(delegationReward > 0) {
                uint256 returnReward = _withdraw(validator);
                reward += returnReward;
            }
        }

        return reward;
    }

    /**
    * @dev Helper function to help to calculate number of validator to delegate based on input amount.
    * @param delegateAmount Fx Amount to stake.
    * @return Number of validators to delegate.
    */
    function _calculateNumberofValidators(
        uint256 delegateAmount
    ) internal view returns (uint256) {
        uint256 numValidators;
        uint256 delegateAmountInEther = delegateAmount / 10**18;

        uint256 valLength = getValLength();
        while (delegateAmountInEther >= 10) {
            delegateAmountInEther /= 10;
            numValidators++;
        }

        return (numValidators == 0) ? 1 : (numValidators > valLength
                ? valLength
                : numValidators);
    }

    /**
    * @dev Helper function to help to query total FX delegation.
    */
    function _getUnderlyingFX() internal view returns (uint256) {
        uint256 totalAmount;
        uint256 valLength = getValLength();
        for (uint256 i; i < valLength; i++) {
            string memory validator = valInfo[i].validator;
            (, uint256 delegationAmount) = _delegation(validator, address(this));
            totalAmount += delegationAmount;
        }
        return totalAmount;
    }

    function _claim(address account, address receiver) private returns (uint256) {
        _updateRewards(account);
        UserInfo storage user = userInfo[account];
        uint256 tokenAmount = user.claimableReward;
        user.claimableReward = 0;

        if (tokenAmount > 0) {
            IERC20Upgradeable(rewardToken()).safeTransfer(receiver, tokenAmount);
            emit Claim(account, tokenAmount);
        }

        return tokenAmount;
    }

    function _updateRewards(address account) private {
        uint256 blockReward = IRewardDistributor(distributor).distribute();

        uint256 supply = totalSupply();
        uint256 _cumulativeRewardPerToken = vaultInfo.cumulativeRewardPerToken;
        if (supply > 0 && blockReward > 0) {
            _cumulativeRewardPerToken = _cumulativeRewardPerToken + (blockReward * (PRECISION) / (supply));
            vaultInfo.cumulativeRewardPerToken = _cumulativeRewardPerToken;
        }

        // cumulativeRewardPerToken can only increase
        // so if cumulativeRewardPerToken is zero, it means there are no rewards yet
        if (_cumulativeRewardPerToken == 0) {
            return;
        }

        if (account != address(0)) {
            UserInfo storage user = userInfo[account];
            uint256 stakedAmount = balanceOf(account);
            uint256 accountReward = stakedAmount * (_cumulativeRewardPerToken - (user.previousCumulatedRewardPerToken)) / (PRECISION);
            uint256 _claimableReward = user.claimableReward + (accountReward);

            user.claimableReward = _claimableReward;
            user.previousCumulatedRewardPerToken = _cumulativeRewardPerToken;
        }
    }

    function _beforeTokenTransfer(address from, address to, uint256 amount)
        internal
        whenNotPaused
        override
    {
        _updateRewards(from);
        _updateRewards(to);

        super._beforeTokenTransfer(from, to, amount);
    }

    function _authorizeUpgrade(
        address
    ) internal override onlyRole(OWNER_ROLE) {} 


    /**************************************** Public/External View Functions ****************************************/

    /**
     * @notice Return total asset(FX) deposited
     * @return Amount of asset(FX) deposited
     */
    function totalAssets() public view override returns (uint256) {
        uint256 underlying = _getUnderlyingFX();
        return underlying;
    }

    function getValLength() public view returns (uint256) {
        return vaultInfo.length;
    }

    /**
     * @notice Return delegation share and fx amount
     */
    function getDelegationInfo(
        uint256 index
    ) external view returns (uint256, uint256) {
        (uint256 sharesAmount, uint256 delegationAmount) = _delegation(valInfo[index].validator, address(this));
        return (sharesAmount, delegationAmount);
    }

    /**
     * @notice Return validator address and allocPoint
     */
    function getValInfo(uint256 index) public view returns (uint256, string memory) {
        return (valInfo[index].allocPoint, valInfo[index].validator);
    }

    /**
     * @notice Return total delegation reward
     */
    function getTotalDelegationRewards() public view returns (uint256) {
        uint256 totalAmount;
        uint256 valLength = getValLength();
        for (uint256 i; i < valLength; i++) {
            string memory validator = valInfo[i].validator;
            uint256 delegationReward = _delegationRewards(validator, address(this));
            totalAmount += delegationReward;
        }
        return totalAmount + pendingFxReward;
    }

    function getVaultConfigs() public view returns (uint256, uint256, uint256, uint256) {
        return (MIN_COMPOUND_AMOUNT, CAP_STAKE_FX_TARGET, UNSTAKE_FX_TARGET, STAKE_FX_TARGET);
    }

    function rewardToken() public view returns (address) {
        return IRewardDistributor(distributor).rewardToken();
    }

    function claimable(address account) public view returns (uint256) {
        UserInfo memory user = userInfo[account];
        uint256 stakedAmount = balanceOf(account);
        if (stakedAmount == 0) {
            return user.claimableReward;
        }
        uint256 supply = totalSupply();
        uint256 pendingRewards = IRewardDistributor(distributor).pendingRewards() * (PRECISION);
        uint256 nextCumulativeRewardPerToken = vaultInfo.cumulativeRewardPerToken + (pendingRewards / (supply));
        return user.claimableReward + (
            stakedAmount * (nextCumulativeRewardPerToken - (user.previousCumulatedRewardPerToken)) / (PRECISION));
    }

    /**************************************** Only Governor Functions ****************************************/

    function addValidator(
        string memory _validator,
        uint256 _allocPoint
    ) external onlyRole(GOVERNOR_ROLE) {
        require(addedValidator[_validator] == false, "addedVal");
        valInfo[vaultInfo.length].validator = _validator;
        valInfo[vaultInfo.length].allocPoint = _allocPoint;

        vaultInfo.length++;
        vaultInfo.totalAllocPoint += _allocPoint;

        addedValidator[_validator]=true;

        emit ValidatorAdded(_validator, _allocPoint);
    }

    /**
     * @notice remove validators which has 0 allocPoint and 0 delegation in the list 
     */
    function removeValidator() external onlyRole(GOVERNOR_ROLE) {
        VaultInfo memory vault = vaultInfo;
        uint256 vaultLength = vault.length;

        for (uint256 i = 0; i < vaultLength; i++) {
            if (valInfo[i].allocPoint == 0) {
                string memory val = valInfo[i].validator;
                (uint256 sharesAmount, ) = _delegation(val, address(this));
                if (sharesAmount == 0) {
                    addedValidator[val] = false;
                    uint256 lastIndex = vaultLength - 1;
                    valInfo[i] = valInfo[lastIndex];
                    delete valInfo[lastIndex];

                    emit ValidatorRemoved(val);
                    vaultLength--;
                    i--;
                }
            }
        }
        vaultInfo.length = vaultLength;
    }

    function updateValidator(
        uint256 id,
        uint256 newAllocPoint
    ) external onlyRole(GOVERNOR_ROLE) {
        require(id < vaultInfo.length, "Invalid ID");
        uint256 oldAllocPoint = valInfo[id].allocPoint;

        vaultInfo.totalAllocPoint = vaultInfo.totalAllocPoint + newAllocPoint - oldAllocPoint;
        valInfo[id].allocPoint = newAllocPoint;

        emit ValidatorUpdated(valInfo[id].validator, newAllocPoint);
    }

    function updateConfigs(uint256 newMinCompound, uint256 newCapStakeFxTarget, uint256 newUnstakeFxTarget, uint256 newStakeFxTarget) external onlyRole(GOVERNOR_ROLE) {
        MIN_COMPOUND_AMOUNT = newMinCompound;
        CAP_STAKE_FX_TARGET = newCapStakeFxTarget;
        UNSTAKE_FX_TARGET = newUnstakeFxTarget;
        STAKE_FX_TARGET = newStakeFxTarget;
    }

    function updateFees(uint256 newFeeOnReward, uint256 newFeeOnCompounder, uint256 newFeeOnWithdrawal) external onlyRole(GOVERNOR_ROLE) {
        feeOnReward = newFeeOnReward;
        feeOnCompounder = newFeeOnCompounder;
        feeOnWithdrawal = newFeeOnWithdrawal;
    }

    /**************************************** Only Owner Functions ****************************************/

    function updateVestedFX(address newAddress) external onlyRole(OWNER_ROLE) {
        vestedFX = newAddress;
        emit VestedFXChanged(newAddress);
    }

    function updateFeeTreasury(address newAddress) external onlyRole(OWNER_ROLE) {
        feeTreasury = newAddress;
        emit FeeTreasuryChanged(newAddress);
    }
    
    function updateDistributor(address newAddress) external onlyRole(OWNER_ROLE) {
        distributor = newAddress;
        emit DistributorChanged(newAddress);
    }

    function recoverToken(
        address token,
        uint256 amount,
        address _recipient
    ) external onlyRole(OWNER_ROLE) {
        require(_recipient != address(0), "Send to zero address");
        IERC20Upgradeable(token).safeTransfer(_recipient, amount);
    }

    function recoverFx(
        uint256 safeAmount,
        address _recipient
    ) external onlyRole(OWNER_ROLE) {
        address recipient = payable(_recipient);
        (bool success, ) = recipient.call{value: safeAmount}("");
        require(success, "Failed to send FX");
    }

    /**************************************************************
     * @dev Initialize the states
     *************************************************************/

    function initialize(
        address _asset,
        address _owner,
        address _governor
    ) public initializer {
        __BaseVaultInit(
            _asset,
            "Staked FX Token",
            "StFX",
            _owner,
            _governor
        );
        __Governable_init(_owner, _governor);
        __UUPSUpgradeable_init();
    }
}
          

// SPDX-License-Identifier: Apache-2.0

pragma solidity ^0.8.0;

interface IWFX {
    function deposit() external payable;

    function withdraw(address payable to, uint256 value) external;

    function transferFrom(address from, address to, uint256 amount) external;
}
          

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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

import {IERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import {SafeERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import {MathUpgradeable} from "@openzeppelin/contracts-upgradeable/utils/math/MathUpgradeable.sol";
import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import {ReentrancyGuardUpgradeable} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";

import {IVestedFX} from "./interfaces/IVestedFX.sol";
import {IRewardDistributor} from "./interfaces/IRewardDistributor.sol";
import {IWFX} from "./interfaces/IWFX.sol";
import {BaseVault} from "./vaults/BaseVault.sol";
import {PrecompileStaking} from "./imp/PrecompileStaking.sol";

contract StakeFXVaultV2 is
    Initializable,
    UUPSUpgradeable,
    PrecompileStaking,
    ReentrancyGuardUpgradeable,
    BaseVault
{
    using SafeERC20Upgradeable for IERC20Upgradeable;
    using MathUpgradeable for uint256;

    uint256 internal constant BIPS_DIVISOR = 10000;
    uint256 internal constant PRECISION = 1e30;
    address constant WFX = 0x80b5a32E4F032B2a058b4F29EC95EEfEEB87aDcd;  // WFX mainnet: 0x80b5a32E4F032B2a058b4F29EC95EEfEEB87aDcd; WFX testnet: 0x3452e23F9c4cC62c70B7ADAd699B264AF3549C19

    uint256 public pendingFxReward;             // FX delegation rewards inside the contract pending for compound
    uint256 public feeOnReward;                 // Compound reward protocol fee
    uint256 public feeOnCompounder;             // Compound reward compounder fee
    uint256 public feeOnWithdrawal;             // Withdrawal fee
    address public vestedFX;                    // Contract that stored user's withdrawal info
    address public feeTreasury;                 // Contract that keep compound reward fee
    address public distributor;                 // Reward token distributor

    uint256 private MIN_COMPOUND_AMOUNT;        // Minimum reward amount to compound when stake happen
    uint256 private CAP_STAKE_FX_TARGET;        // Cap amount of stFX
    uint256 private STAKE_FX_TARGET;            // Target stake amount to do whole validator list delegate
    uint256 private UNSTAKE_FX_TARGET;          // Target unstake amount to split undelegate
    
    VaultInfo public vaultInfo;                     // Vault Info
    mapping(uint256 => ValInfo) public valInfo;     // Validator info
    mapping(address => UserInfo) public userInfo;   // User info
    mapping(string => bool) public addedValidator;  // True if validator is added

    struct VaultInfo {
        uint256 stakeId;
        uint256 unstakeId;
        uint256 length;
        uint256 totalAllocPoint;
        uint256 cumulativeRewardPerToken;
    }

    struct ValInfo {
        uint256 allocPoint;
        string validator;
    }

    struct UserInfo {
        uint256 claimableReward;
        uint256 previousCumulatedRewardPerToken;
    }

    event Stake(address indexed user, uint256 amount, uint256 shares);
    event Unstake(address indexed user, uint256 amount, uint256 shares);
    event Compound(address indexed user, uint256 compoundAmount);
    event Claim(address receiver, uint256 amount);
    event ValidatorAdded(string val, uint256 newAllocPoint);
    event ValidatorRemoved(string val);
    event ValidatorUpdated(string val, uint256 newAllocPoint);
    event VestedFXChanged(address newAddress);
    event FeeTreasuryChanged(address newAddress);
    event DistributorChanged(address newAddress);
    event ValidatorRedelegated(string srcVal, string dstVal, uint256 sharesAmount, uint256 redelegatedShares);

    receive() external payable {}

    modifier onlyVestedFX() {
        require(msg.sender == vestedFX, "Only VestedFX can call");
        _;
    }

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    /****************************************** Core External Functions ******************************************/
    /**
     * @notice user stake FX to this contract
     */
    function stake() external payable nonReentrant whenNotPaused {
        require(msg.value > 0, "Stake: 0 amount");
        uint256 totalAsset = totalAssets();
        require(msg.value + totalAsset <= CAP_STAKE_FX_TARGET, "Stake: > Cap");

        uint256 delegationReward = getTotalDelegationRewards();
        if(delegationReward >= MIN_COMPOUND_AMOUNT) {
            _compound();
        }
        _claim(msg.sender, msg.sender);

        uint256 shares = previewDeposit(msg.value);
        _mint(msg.sender, shares);

        _stake(msg.value);

        emit Stake(msg.sender, msg.value, shares);
    }

    /**
     * @notice user stake WFX to this contract
     */
    function stakeWFX(uint256 amount) external nonReentrant whenNotPaused {
        require(amount > 0, "Stake: 0 amount");
        uint256 totalAsset = totalAssets();
        require(amount + totalAsset <= CAP_STAKE_FX_TARGET, "Stake: > Cap");

        uint256 delegationReward = getTotalDelegationRewards();
        if(delegationReward >= MIN_COMPOUND_AMOUNT) {
            _compound();
        }
        _claim(msg.sender, msg.sender);

        IWFX(WFX).transferFrom(msg.sender, address(this), amount); 
        IWFX(WFX).withdraw(payable(address(this)), amount);

        uint256 shares = previewDeposit(amount);
        _mint(msg.sender, shares);

        _stake(amount);

        emit Stake(msg.sender, amount, shares);
    }

    /**
     * @notice user unstake/ request undelegate FX
     * @param amount User's fx-LP receipt tokens
     */
    function unstake(uint256 amount) external whenNotPaused {
        require(amount > 0, "Unstake: 0 amount");
        uint256 sharesBalance = balanceOf(msg.sender);
        require(sharesBalance >= amount, "Amount > stake");

        // Add compound if contract size allow
        uint256 delegationReward = getTotalDelegationRewards();
        if(delegationReward >= MIN_COMPOUND_AMOUNT) {
            _compound();
        }
        _claim(msg.sender, msg.sender);

        uint256 undelegateAmount = previewRedeem(amount);
        uint256 undelegateAmountAfterFee = undelegateAmount * (BIPS_DIVISOR - feeOnWithdrawal) / BIPS_DIVISOR;

        _burn(msg.sender, amount);
        if (undelegateAmountAfterFee > 0) {
            _unstake(undelegateAmountAfterFee);
        }
     
        emit Unstake(msg.sender, undelegateAmountAfterFee, amount);
    }

    /**
     * @notice transfer user delegation shares to this contract
     * @param val validator address
     * @param amount Amount of user's delegate shares transferred to this contract
     */
    function entrustDelegatedShare(string memory val, uint256 amount) external nonReentrant whenNotPaused {
        require(amount > 0, "Entrust: 0 share");

        (uint256 sharesAmount, uint256 delegationAmount) = _delegation(val, msg.sender);
        require(sharesAmount >= amount, "Not enough share");

        uint256 delegationReward = getTotalDelegationRewards();
        if(delegationReward >= MIN_COMPOUND_AMOUNT) {
            _compound();
        }
        _claim(msg.sender, msg.sender);
        
        uint256 totalAsset = totalAssets();
        uint256 estimateDelegateAmount = amount / sharesAmount * delegationAmount;
        require(estimateDelegateAmount + totalAsset <= CAP_STAKE_FX_TARGET, "Stake: > Cap");

        uint256 supply = totalSupply();
        (uint256 fxAmountToTransfer, uint256 returnReward) = _transferFromShares(val, msg.sender, address(this), amount);

        pendingFxReward += returnReward;

        uint256 shares = (fxAmountToTransfer == 0 || supply == 0)
                ? _initialConvertToShares(fxAmountToTransfer, MathUpgradeable.Rounding.Down)
                : fxAmountToTransfer.mulDiv(supply, totalAsset, MathUpgradeable.Rounding.Down);

        _mint(msg.sender, shares);

        emit Stake(msg.sender, fxAmountToTransfer, shares); 
    }

    function claim(address receiver) external nonReentrant returns (uint256) {
        return _claim(msg.sender, receiver);
    }

    /**
     * @notice compound delegation rewards
     */
    function compound() external nonReentrant whenNotPaused {
        _compound();
    }

    function sendVestedFX(
        uint256 safeAmount
    ) external onlyVestedFX {
        address recipient = payable(msg.sender);
        (bool success, ) = recipient.call{value: safeAmount}("");
        require(success, "Failed to send FX");
    }

    function updateRewards() external nonReentrant {
        _updateRewards(address(0));
    }

    /**************************************** Internal and Private Functions ****************************************/

    /**
    * @dev Helper function to delegate FX amount to validators.
    * @param  amount  The amount: FX delegate to validators.
    */
    function _stake(uint256 amount) internal {
        VaultInfo memory vault = vaultInfo;
        uint256 totalAllocPoint = vault.totalAllocPoint;
        uint256 index = vault.stakeId;
        uint256 vaultLength = vault.length;
        uint256 totalReturnReward;
        uint256 _totalAssets = totalAssets();

        // After execute removeValidator, stakeId may equal or greater than vaultLength
        if (index >= vaultLength) {
            index = 0;
        }

        uint256 numValidators = _calculateNumberofValidators(amount);
        uint256 amountPerValidator = amount / numValidators;
        uint256 remainingAmount = amount;
        uint256 delegateAmount;
        
        while (remainingAmount != 0) {
            ValInfo memory val = valInfo[index];
            uint256 allocPoint = val.allocPoint;
            index = (index + 1) % vaultLength;

            if (allocPoint == 0) {
                continue;
            }
            
            if (_totalAssets >= CAP_STAKE_FX_TARGET) {
                delegateAmount = remainingAmount;
            } else {
                (, uint256 delegationAmount) = _delegation(val.validator, address(this));
                uint256 maxValSize = allocPoint * CAP_STAKE_FX_TARGET / totalAllocPoint;

                if (delegationAmount >= maxValSize) {
                    continue;
                }

                if (remainingAmount <= amountPerValidator) {
                    delegateAmount = remainingAmount;
                } else {
                    delegateAmount = amountPerValidator;
                }
            }

            (, uint256 returnReward) = _delegate(val.validator, delegateAmount);
            _totalAssets += delegateAmount;
            totalReturnReward += returnReward;
            remainingAmount -= delegateAmount;
        }

        vaultInfo.stakeId = index;
        pendingFxReward += totalReturnReward;
    }
    
    /**
    * @dev Helper function to undelegate FX amount from validators.
    * @param  amount  The amount: FX to unstake from the vault.
    */
    function _unstake(uint256 amount) internal {
        VaultInfo memory vault = vaultInfo;
        uint256 index = vault.unstakeId;
        uint256 vaultLength = vault.length;

        uint256 remainingAmount = amount;
        uint256 totalReward;        
        uint256 returnUndelegatedAmount;
        uint256 returnReward;
        uint256 endTime;
        
        // After execute removeValidator, stakeId may equal or greater than vaultLength
        if (index >= vaultLength) {
            index = 0;
        }   
        // If contract byte size exceed limit, divide to half part can be removed
        if (amount >= UNSTAKE_FX_TARGET) {
            uint256 halfOfUndelegateAmount = amount / 2; 
            (returnUndelegatedAmount, returnReward, endTime) = _toUndelegate(index, halfOfUndelegateAmount);
                
            remainingAmount -= returnUndelegatedAmount;
            index = (index + 1) % vaultLength;
            totalReward += returnReward;
        }

        while (remainingAmount != 0) {
            (returnUndelegatedAmount, returnReward, endTime) = _toUndelegate(index, remainingAmount);
            
            remainingAmount -= returnUndelegatedAmount;
            index = (index + 1) % vaultLength;
            totalReward += returnReward;
        }

        IVestedFX(vestedFX).lockWithEndTime(
            msg.sender,            
            amount,
            endTime
        );

        vaultInfo.unstakeId = index;
        pendingFxReward += totalReward;
    }

    /**
    * @dev Helper function to undelegate FX amount from validators.
    * @param  index Validator ID in validator list.
    * @param  remainingAmount Amount to undelegate from validators.
    */
    function _toUndelegate(uint256 index, uint256 remainingAmount) internal returns(uint256, uint256, uint256) {
        (uint256 sharesAmount, uint256 delegationAmount) = _delegation(valInfo[index].validator, address(this));

        uint256 amountToUndelegate;
        uint256 returnReward;
        uint256 endTime;

        if (delegationAmount > 0) {
            if (delegationAmount >= remainingAmount) {
                amountToUndelegate = remainingAmount;
            } else {
                amountToUndelegate = delegationAmount;
            }

            uint256 shareToWithdraw = (sharesAmount * amountToUndelegate) / delegationAmount;
            if (shareToWithdraw > 0) {
                (amountToUndelegate, returnReward, endTime) = _undelegate(valInfo[index].validator, shareToWithdraw);
            }
        }

        return (amountToUndelegate, returnReward, endTime);
    }

    /**
    * @dev Helper function to compound FX amount from validators.
    */
    function _compound() internal {
        uint256 delegateReward = _withdrawReward() + pendingFxReward;
        pendingFxReward = 0;

        uint256 feeProtocol = (delegateReward * feeOnReward) / BIPS_DIVISOR;
        uint256 feeCompounder = (delegateReward * feeOnCompounder) / BIPS_DIVISOR;

        delegateReward = delegateReward - feeProtocol - feeCompounder;
        _stake(delegateReward);

        address treasury = payable(feeTreasury);
        address user = payable(msg.sender);
        (bool successTreasury, ) = treasury.call{value: feeProtocol}("");
        (bool successUser, ) = user.call{value: feeCompounder}("");
        require(successTreasury && successUser, "Failed to send FX");

        emit Compound(msg.sender, delegateReward);
    }

    /**
    * @dev Helper function to withdraw delegation fx rewards from all validators.
    */
    function _withdrawReward() internal returns (uint256) {
        VaultInfo memory vault = vaultInfo;
        uint256 reward = 0;
        
        uint256 vaultLength = vault.length;

        for (uint256 i; i < vaultLength; i++) {
            string memory validator = valInfo[i].validator;
            uint256 delegationReward = _delegationRewards(validator, address(this));
            if(delegationReward > 0) {
                uint256 returnReward = _withdraw(validator);
                reward += returnReward;
            }
        }

        return reward;
    }

    /**
    * @dev Helper function to help to calculate number of validator to delegate based on Log10 input amount.
    * @param delegateAmount Fx Amount to stake.
    * @return Number of validators to delegate.
    */
    function _calculateNumberofValidators(
        uint256 delegateAmount
    ) internal view returns (uint256) {
        uint256 numValidators;
        uint256 delegateAmountInEther = delegateAmount / 10**18;

        uint256 valLength = getValLength();
        while (delegateAmountInEther >= 10) {
            delegateAmountInEther /= 10;
            numValidators++;
        }

        return (numValidators == 0) ? 1 : (numValidators > valLength
                ? valLength
                : numValidators);
    }

    /**
    * @dev Helper function to help to query total FX delegation.
    */
    function _getUnderlyingFX() internal view returns (uint256) {
        uint256 totalAmount;
        uint256 valLength = getValLength();
        for (uint256 i; i < valLength; i++) {
            string memory validator = valInfo[i].validator;
            (, uint256 delegationAmount) = _delegation(validator, address(this));
            totalAmount += delegationAmount;
        }
        return totalAmount;
    }

    function _claim(address account, address receiver) private returns (uint256) {
        _updateRewards(account);
        UserInfo storage user = userInfo[account];
        uint256 tokenAmount = user.claimableReward;
        user.claimableReward = 0;

        if (tokenAmount > 0) {
            IERC20Upgradeable(rewardToken()).safeTransfer(receiver, tokenAmount);
            emit Claim(account, tokenAmount);
        }

        return tokenAmount;
    }

    function _updateRewards(address account) private {
        uint256 blockReward = IRewardDistributor(distributor).distribute();

        uint256 supply = totalSupply();
        uint256 _cumulativeRewardPerToken = vaultInfo.cumulativeRewardPerToken;
        if (supply > 0 && blockReward > 0) {
            _cumulativeRewardPerToken = _cumulativeRewardPerToken + (blockReward * (PRECISION) / (supply));
            vaultInfo.cumulativeRewardPerToken = _cumulativeRewardPerToken;
        }

        // cumulativeRewardPerToken can only increase
        // so if cumulativeRewardPerToken is zero, it means there are no rewards yet
        if (_cumulativeRewardPerToken == 0) {
            return;
        }

        if (account != address(0)) {
            UserInfo storage user = userInfo[account];
            uint256 stakedAmount = balanceOf(account);
            uint256 accountReward = stakedAmount * (_cumulativeRewardPerToken - (user.previousCumulatedRewardPerToken)) / (PRECISION);
            uint256 _claimableReward = user.claimableReward + (accountReward);

            user.claimableReward = _claimableReward;
            user.previousCumulatedRewardPerToken = _cumulativeRewardPerToken;
        }
    }

    function _beforeTokenTransfer(address from, address to, uint256 amount)
        internal
        whenNotPaused
        override
    {
        _updateRewards(from);
        _updateRewards(to);

        super._beforeTokenTransfer(from, to, amount);
    }

    function _authorizeUpgrade(
        address
    ) internal override onlyRole(OWNER_ROLE) {} 


    /**************************************** Public/External View Functions ****************************************/

    /**
     * @notice Return total asset(FX) deposited
     * @return Amount of asset(FX) deposited
     */
    function totalAssets() public view override returns (uint256) {
        uint256 underlying = _getUnderlyingFX();
        return underlying;
    }

    function getValLength() public view returns (uint256) {
        return vaultInfo.length;
    }

    /**
     * @notice Return validator address and allocPoint
     */
    function getValInfo(uint256 index) public view returns (uint256, string memory) {
        return (valInfo[index].allocPoint, valInfo[index].validator);
    }

    /**
     * @notice Return total delegation reward
     */
    function getTotalDelegationRewards() public view returns (uint256) {
        uint256 totalAmount;
        uint256 valLength = getValLength();
        for (uint256 i; i < valLength; i++) {
            string memory validator = valInfo[i].validator;
            uint256 delegationReward = _delegationRewards(validator, address(this));
            totalAmount += delegationReward;
        }
        return totalAmount + pendingFxReward;
    }

    function getVaultConfigs() public view returns (uint256, uint256, uint256, uint256) {
        return (MIN_COMPOUND_AMOUNT, CAP_STAKE_FX_TARGET, UNSTAKE_FX_TARGET, STAKE_FX_TARGET);
    }

    function rewardToken() public view returns (address) {
        return IRewardDistributor(distributor).rewardToken();
    }

    function claimable(address account) public view returns (uint256) {
        UserInfo memory user = userInfo[account];
        uint256 stakedAmount = balanceOf(account);
        if (stakedAmount == 0) {
            return user.claimableReward;
        }
        uint256 supply = totalSupply();
        uint256 pendingRewards = IRewardDistributor(distributor).pendingRewards() * (PRECISION);
        uint256 nextCumulativeRewardPerToken = vaultInfo.cumulativeRewardPerToken + (pendingRewards / (supply));
        return user.claimableReward + (
            stakedAmount * (nextCumulativeRewardPerToken - (user.previousCumulatedRewardPerToken)) / (PRECISION));
    }

    /**************************************** Only Governor Functions ****************************************/

    function addValidator(
        string memory _validator,
        uint256 _allocPoint
    ) external onlyRole(GOVERNOR_ROLE) {
        require(addedValidator[_validator] == false, "addedVal");
        valInfo[vaultInfo.length].validator = _validator;
        valInfo[vaultInfo.length].allocPoint = _allocPoint;

        vaultInfo.length++;
        vaultInfo.totalAllocPoint += _allocPoint;

        addedValidator[_validator]=true;

        emit ValidatorAdded(_validator, _allocPoint);
    }

    /**
     * @notice remove validators which has 0 allocPoint and 0 delegation in the list 
     */
    function removeValidator() external onlyRole(GOVERNOR_ROLE) {
        VaultInfo memory vault = vaultInfo;
        uint256 vaultLength = vault.length;

        for (uint256 i = 0; i < vaultLength;) {
            if (valInfo[i].allocPoint == 0) {
                string memory val = valInfo[i].validator;
                (uint256 sharesAmount, ) = _delegation(val, address(this));

                if (sharesAmount == 0) {
                    addedValidator[val] = false;
                    uint256 lastIndex = vaultLength - 1;
                    valInfo[i] = valInfo[lastIndex];
                    delete valInfo[lastIndex];

                    emit ValidatorRemoved(val);
                    vaultLength--;
                    // Skip if i == 0 to prevent underflow
                    if (i == 0) {
                        continue;
                    } else {
                        --i;
                    }
                }
            }
            unchecked {
                ++i;
            }
        }
        vaultInfo.length = vaultLength;
    }

    function redelegateValidator(
        uint256 srcId,
        uint256 dstId,
        uint256 redelegateAmount
    ) external onlyRole(GOVERNOR_ROLE) {
        require(srcId < vaultInfo.length && dstId < vaultInfo.length, "Invalid ID");
        ValInfo memory srcVal = valInfo[srcId];
        ValInfo memory dstVal = valInfo[dstId];
        (uint256 sharesAmount,) = _delegation(srcVal.validator, address(this));

        uint256 returnReward;
        uint256 redelegatedShares;        

        require(redelegateAmount <= sharesAmount, "!Amount");
        (redelegatedShares, returnReward, ) = _redelegate(srcVal.validator, dstVal.validator, redelegateAmount);

        pendingFxReward += returnReward;

        emit ValidatorRedelegated(srcVal.validator, dstVal.validator, sharesAmount, redelegatedShares);
    }

    function updateValidator(
        uint256 id,
        uint256 newAllocPoint
    ) external onlyRole(GOVERNOR_ROLE) {
        require(id < vaultInfo.length, "Invalid ID");
        uint256 oldAllocPoint = valInfo[id].allocPoint;

        vaultInfo.totalAllocPoint = vaultInfo.totalAllocPoint + newAllocPoint - oldAllocPoint;
        valInfo[id].allocPoint = newAllocPoint;

        emit ValidatorUpdated(valInfo[id].validator, newAllocPoint);
    }

    function updateConfigs(uint256 newMinCompound, uint256 newCapStakeFxTarget, uint256 newUnstakeFxTarget, uint256 newStakeFxTarget) external onlyRole(GOVERNOR_ROLE) {
        MIN_COMPOUND_AMOUNT = newMinCompound;
        CAP_STAKE_FX_TARGET = newCapStakeFxTarget;
        UNSTAKE_FX_TARGET = newUnstakeFxTarget;
        STAKE_FX_TARGET = newStakeFxTarget;
    }

    /**
     * @notice Update compounding fee percentage for protocol and compounder and user withdrawal percentage
     * require(newFeeOnReward + newFeeOnCompounder) <= BIPS_DIVISOR && newFeeOnWithdrawal <= BIPS_DIVISOR)
     */
    function updateFees(uint256 newFeeOnReward, uint256 newFeeOnCompounder, uint256 newFeeOnWithdrawal) external onlyRole(GOVERNOR_ROLE) {
        feeOnReward = newFeeOnReward;
        feeOnCompounder = newFeeOnCompounder;
        feeOnWithdrawal = newFeeOnWithdrawal;
    }

    /**************************************** Only Owner Functions ****************************************/

    function updateVestedFX(address newAddress) external onlyRole(OWNER_ROLE) {
        vestedFX = newAddress;
        emit VestedFXChanged(newAddress);
    }

    function updateFeeTreasury(address newAddress) external onlyRole(OWNER_ROLE) {
        feeTreasury = newAddress;
        emit FeeTreasuryChanged(newAddress);
    }
    
    function updateDistributor(address newAddress) external onlyRole(OWNER_ROLE) {
        distributor = newAddress;
        emit DistributorChanged(newAddress);
    }

    function recoverToken(
        address token,
        uint256 amount,
        address _recipient
    ) external onlyRole(OWNER_ROLE) {
        require(_recipient != address(0), "Send to zero address");
        if(token != address(0)) {
            IERC20Upgradeable(token).safeTransfer(_recipient, amount);
        } else {
            address recipient = payable(_recipient);
            (bool success, ) = recipient.call{value: amount}("");
            require(success, "Failed to send FX");
        }
    }

    /**************************************************************
     * @dev Initialize the states
     *************************************************************/

    function initialize(
        address _asset,
        address _owner,
        address _governor
    ) public initializer {
        __BaseVaultInit(
            _asset,
            "Staked FX Token",
            "StFX",
            _owner,
            _governor
        );
        // __Governable_init(_owner, _governor);    redundant code
        __UUPSUpgradeable_init();
    }
}
          

// 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 IBeaconUpgradeable {
    /**
     * @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: UNLICENSED

pragma solidity ^0.8.10;

/**
 * @title IPrecompileStaking
 *
 * @dev Interface to interact to network precompile staking contract functions.
 */
interface IPrecompileStaking {

    function delegate(string memory _val) external payable returns (uint256, uint256);

    function undelegate(string memory _val, uint256 _shares) external returns (uint256, uint256, uint256);

    function withdraw(string memory _val) external returns (uint256);

    function transferFromShares(string memory _val, address _from, address _to, uint256 _shares) external returns (uint256, uint256);

    function delegation(string memory _val, address _del) external view returns (uint256, uint256);

    function delegationRewards(string memory _val, address _del) external view returns (uint256);

    function delegateV2(
        string memory _val,
        uint256 _amount
    ) external payable returns (bool _result);

    function undelegateV2(
        string memory _val,
        uint256 _amount
    ) external returns (bool _result);

    function redelegateV2(
        string memory _valSrc,
        string memory _valDst,
        uint256 _amount
    ) external returns (bool _result);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/StorageSlot.sol)
// This file was procedurally generated from scripts/generate/templates/StorageSlot.js.

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:
 * ```solidity
 * 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`, `uint256`._
 * _Available since v4.9 for `string`, `bytes`._
 */
library StorageSlotUpgradeable {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    struct StringSlot {
        string value;
    }

    struct BytesSlot {
        bytes value;
    }

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

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

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

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

    /**
     * @dev Returns an `StringSlot` with member `value` located at `slot`.
     */
    function getStringSlot(bytes32 slot) internal pure returns (StringSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `StringSlot` representation of the string storage pointer `store`.
     */
    function getStringSlot(string storage store) internal pure returns (StringSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := store.slot
        }
    }

    /**
     * @dev Returns an `BytesSlot` with member `value` located at `slot`.
     */
    function getBytesSlot(bytes32 slot) internal pure returns (BytesSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BytesSlot` representation of the bytes storage pointer `store`.
     */
    function getBytesSlot(bytes storage store) internal pure returns (BytesSlot storage r) {
        /// @solidity memory-safe-assembly
        assembly {
            r.slot := store.slot
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

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.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```solidity
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 *
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * 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 prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

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

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts.
     *
     * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
     * constructor.
     *
     * Emits an {Initialized} event.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * A reinitializer may be used after the original initialization step. This is essential to configure modules that
     * are added through upgrades and that require initialization.
     *
     * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
     * cannot be nested. If one is invoked in the context of another, execution will revert.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     *
     * WARNING: setting the version to 255 will prevent any future reinitialization.
     *
     * Emits an {Initialized} event.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

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

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     *
     * Emits an {Initialized} event the first time it is successfully executed.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized != type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }

    /**
     * @dev Returns the highest version that has been initialized. See {reinitializer}.
     */
    function _getInitializedVersion() internal view returns (uint8) {
        return _initialized;
    }

    /**
     * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
     */
    function _isInitializing() internal view returns (bool) {
        return _initializing;
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

import "./math/MathUpgradeable.sol";
import "./math/SignedMathUpgradeable.sol";

/**
 * @dev String operations.
 */
library StringsUpgradeable {
    bytes16 private constant _SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        unchecked {
            uint256 length = MathUpgradeable.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @dev Converts a `int256` to its ASCII `string` decimal representation.
     */
    function toString(int256 value) internal pure returns (string memory) {
        return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMathUpgradeable.abs(value))));
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, MathUpgradeable.log256(value) + 1);
        }
    }

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

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }

    /**
     * @dev Returns true if the two strings are equal.
     */
    function equal(string memory a, string memory b) internal pure returns (bool) {
        return keccak256(bytes(a)) == keccak256(bytes(b));
    }
}
          

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

pragma solidity ^0.8.0;

import "../IERC20Upgradeable.sol";

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

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

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

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

pragma solidity ^0.8.0;

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20Upgradeable {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

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

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

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

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

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)

pragma solidity ^0.8.0;

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

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

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

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal onlyInitializing {
        __Pausable_init_unchained();
    }

    function __Pausable_init_unchained() internal onlyInitializing {
        _paused = false;
    }

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

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

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

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

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

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20Upgradeable is Initializable, ContextUpgradeable, IERC20Upgradeable, IERC20MetadataUpgradeable {
    mapping(address => uint256) private _balances;

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

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    function __ERC20_init(string memory name_, string memory symbol_) internal onlyInitializing {
        __ERC20_init_unchained(name_, symbol_);
    }

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

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

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

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

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

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

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

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

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

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

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

        return true;
    }

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

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

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

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

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

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

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

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

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

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

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

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

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

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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 Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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: Apache-2.0

pragma solidity ^0.8.0;

interface IVestedFX {
    
    struct VestingSchedule {
        uint64 startTime;
        uint64 endTime;
        uint256 quantity;
        uint256 vestedQuantity;
    }

    function lockWithEndTime(address account, uint256 quantity, uint256 endTime) external;

    function getVestingSchedules(address account) external view returns (VestingSchedule[] memory);

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20Upgradeable.sol";
import "../extensions/IERC20PermitUpgradeable.sol";
import "../../../utils/AddressUpgradeable.sol";

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

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20Upgradeable token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20Upgradeable token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20Upgradeable token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20Upgradeable token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20Upgradeable token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
     * 0 before setting it to a non-zero value.
     */
    function forceApprove(IERC20Upgradeable token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    function safePermit(
        IERC20PermitUpgradeable token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20Upgradeable token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20Upgradeable token, bytes memory data) private returns (bool) {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return
            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && AddressUpgradeable.isContract(address(token));
    }
}
          

// 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 (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/IERC20Permit.sol";
import "../../../utils/Address.sol";

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

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
     * 0 before setting it to a non-zero value.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return
            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library MathUpgradeable {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @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 == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                // The surrounding unchecked block does not change this fact.
                // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1, "Math: mulDiv overflow");

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10 ** 64) {
                value /= 10 ** 64;
                result += 64;
            }
            if (value >= 10 ** 32) {
                value /= 10 ** 32;
                result += 32;
            }
            if (value >= 10 ** 16) {
                value /= 10 ** 16;
                result += 16;
            }
            if (value >= 10 ** 8) {
                value /= 10 ** 8;
                result += 8;
            }
            if (value >= 10 ** 4) {
                value /= 10 ** 4;
                result += 4;
            }
            if (value >= 10 ** 2) {
                value /= 10 ** 2;
                result += 2;
            }
            if (value >= 10 ** 1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
        }
    }
}
          

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {ReentrancyGuardUpgradeable} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";

import {Governable} from "./common/Governable.sol";
import "./interfaces/IMintable.sol";

contract Vester is IERC20, Initializable, UUPSUpgradeable, ReentrancyGuardUpgradeable, Governable {
    using SafeERC20 for IERC20;

    string public name;
    string public symbol;
    uint8 public constant decimals = 18;

    uint256 public vestingDuration;

    address public esToken;
    address public claimableToken;

    uint256 public override totalSupply;

    mapping (address => uint256) public balances;
    mapping (address => uint256) public cumulativeClaimAmounts;
    mapping (address => uint256) public claimedAmounts;
    mapping (address => uint256) public lastVestingTimes;

    mapping (address => bool) public isHandler;

    event Claim(address receiver, uint256 amount);
    event Deposit(address account, uint256 amount);
    event Withdraw(address account, uint256 claimedAmount, uint256 balance);

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }


    /**************************************************************
     * Core user functions 
     *************************************************************/
     
    function deposit(uint256 _amount) external nonReentrant {
        _deposit(msg.sender, _amount);
    }

    function depositForAccount(address _account, uint256 _amount) external nonReentrant {
        _validateHandler();
        _deposit(_account, _amount);
    }

    function withdraw() external nonReentrant {
        address account = msg.sender;
        address _receiver = account;
        _claim(account, _receiver);

        uint256 claimedAmount = cumulativeClaimAmounts[account];
        uint256 balance = balances[account];
        uint256 totalVested = balance + (claimedAmount);
        require(totalVested > 0, "Vester: vested amount is zero");

        IERC20(esToken).safeTransfer(_receiver, balance);
        _burn(account, balance);

        delete cumulativeClaimAmounts[account];
        delete claimedAmounts[account];
        delete lastVestingTimes[account];

        emit Withdraw(account, claimedAmount, balance);
    }

    function claim() external nonReentrant returns (uint256) {
        return _claim(msg.sender, msg.sender);
    }

    function claimForAccount(address _account, address _receiver) external nonReentrant returns (uint256) {
        _validateHandler();
        return _claim(_account, _receiver);
    }

    /**************************************************************
     * View functions 
     *************************************************************/

    function claimable(address _account) public view returns (uint256) {
        uint256 amount = cumulativeClaimAmounts[_account] - (claimedAmounts[_account]);
        uint256 nextClaimable = _getNextClaimableAmount(_account);
        return amount + (nextClaimable);
    }

    function getTotalVested(address _account) public view returns (uint256) {
        return balances[_account] + (cumulativeClaimAmounts[_account]);
    }

    function balanceOf(address _account) public view override returns (uint256) {
        return balances[_account];
    }

    function getVestedAmount(address _account) public view returns (uint256) {
        uint256 balance = balances[_account];
        uint256 cumulativeClaimAmount = cumulativeClaimAmounts[_account];
        return balance + (cumulativeClaimAmount);
    }

    /**************************************************************
     * Internal functions 
     *************************************************************/

    function _mint(address _account, uint256 _amount) private {
        require(_account != address(0), "Vester: mint to the zero address");

        totalSupply = totalSupply + (_amount);
        balances[_account] = balances[_account] + (_amount);

        emit Transfer(address(0), _account, _amount);
    }

    function _burn(address _account, uint256 _amount) private {
        require(_account != address(0), "Vester: burn from the zero address");

        balances[_account] = balances[_account] - (_amount);  // "Vester: burn amount exceeds balance"
        totalSupply = totalSupply - (_amount);

        emit Transfer(_account, address(0), _amount);
    }

    function _deposit(address _account, uint256 _amount) private {
        require(_amount > 0, "Vester: invalid _amount");

        _claim(_account, _account);

        IERC20(esToken).safeTransferFrom(_account, address(this), _amount);

        _mint(_account, _amount);

        emit Deposit(_account, _amount);
    }

    function _claim(address _account, address _receiver) private returns (uint256) {
        _updateVesting(_account);
        uint256 amount = claimable(_account);
        claimedAmounts[_account] = claimedAmounts[_account] + (amount);
        IERC20(claimableToken).safeTransfer(_receiver, amount);
        emit Claim(_account, amount);
        return amount;
    }

    function _updateVesting(address _account) private {
        uint256 amount = _getNextClaimableAmount(_account);
        lastVestingTimes[_account] = block.timestamp;

        if (amount == 0) {
            return;
        }

        // transfer claimableAmount from balances to cumulativeClaimAmounts
        _burn(_account, amount);
        cumulativeClaimAmounts[_account] = cumulativeClaimAmounts[_account] + (amount);

        IMintable(esToken).burn(amount);
    }

    function _getNextClaimableAmount(address _account) internal view returns (uint256) {
        uint256 balance = balances[_account];
        if (balance == 0) { return 0; }

        uint256 timeDiff = block.timestamp - (lastVestingTimes[_account]);

        uint256 vestedAmount = getVestedAmount(_account);
        uint256 claimableAmount = vestedAmount * (timeDiff) / (vestingDuration);

        if (claimableAmount < balance) {
            return claimableAmount;
        }

        return balance;
    }

    function _validateHandler() private view {
        require(isHandler[msg.sender], "Vester: forbidden");
    }

    /**************************************************************
     * Empty ERC20 implementation functions 
     *************************************************************/

    // empty implementation, tokens are non-transferrable
    function transfer(address /* recipient */, uint256 /* amount */) public override returns (bool) {
        revert("Vester: non-transferrable");
    }

    // empty implementation, tokens are non-transferrable
    function allowance(address /* owner */, address /* spender */) public view virtual override returns (uint256) {
        return 0;
    }

    // empty implementation, tokens are non-transferrable
    function approve(address /* spender */, uint256 /* amount */) public virtual override returns (bool) {
        revert("Vester: non-transferrable");
    }

    // empty implementation, tokens are non-transferrable
    function transferFrom(address /* sender */, address /* recipient */, uint256 /* amount */) public virtual override returns (bool) {
        revert("Vester: non-transferrable");
    }

    /**************************************************************
     * Only Owner functions 
     *************************************************************/
    function _authorizeUpgrade(address) internal override onlyRole(OWNER_ROLE) {}

    // to help users who accidentally send their tokens to this contract
    function recoverToken(address _token, address _account, uint256 _amount) external onlyRole(OWNER_ROLE) {
        IERC20(_token).safeTransfer(_account, _amount);
    }

    function setHandler(address _handler, bool _isActive) external onlyRole(OWNER_ROLE) {
        isHandler[_handler] = _isActive;
    }

    function mintEsToken(uint256 _amount) external nonReentrant onlyRole(OWNER_ROLE){
        IERC20(claimableToken).transferFrom(msg.sender, address(this), _amount);
        IMintable(esToken).mint(msg.sender, _amount);
    }

    /**************************************************************
     * @dev Initialize smart contract functions - only called once
     *************************************************************/
    function initialize(
        string memory _name,
        string memory _symbol,
        uint256 _vestingDuration,
        address _esToken,
        address _claimableToken,
        address _owner,
        address _governor
    ) public initializer{
        name = _name;
        symbol = _symbol;

        vestingDuration = _vestingDuration;

        esToken = _esToken;
        claimableToken = _claimableToken;
        __Governable_init(_owner, _governor);
        __UUPSUpgradeable_init();
    }
}
          

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

import {IERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import {SafeERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";

import {IStakeFXVault} from "./interfaces/IStakeFXVault.sol";
import {PrecompileStaking} from "./imp/PrecompileStaking.sol";

contract MultiCall is
    Initializable,
    UUPSUpgradeable,
    OwnableUpgradeable,
    PrecompileStaking
{
    using SafeERC20Upgradeable for IERC20Upgradeable;

    address stFX;

    struct ValidatorDelegationInfo {
        string validator;
        uint256 allocPoint;
        uint256 delegationAmount;
        uint256 delegationReward;
    }

    struct ValidatorUserDelegationInfo {
        string validator;
        uint256 delegationAmount;
        uint256 allowanceShares;
    }

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    /**************************************** Public/External View Functions ****************************************

    /**
    * @dev Get all validator delegation for stFX.
    */
    function getAllValidatorDelegation() external view returns (ValidatorDelegationInfo[] memory validatorDelegations) {
        uint256 validatorsLength = IStakeFXVault(stFX).getValLength();

        validatorDelegations = new ValidatorDelegationInfo[](validatorsLength);
        for (uint256 i = 0; i < validatorsLength; i++) {
            (uint256 valAllocPoint, string memory validatorAddress) = IStakeFXVault(stFX).getValInfo(i);
            (, uint256 delegationAmount) = _delegation(validatorAddress, stFX);
            uint256 delegationReward = _delegationRewards(validatorAddress, stFX);

            validatorDelegations[i] = ValidatorDelegationInfo({
                validator: validatorAddress,
                allocPoint: valAllocPoint,
                delegationAmount: delegationAmount,
                delegationReward: delegationReward
            });
        }
    }

    /**
    * @dev Get All Validator User Delegation
    */
    function getAllValidatorUserDelegation(address user) external view returns (ValidatorUserDelegationInfo[] memory validatorUserDelegations) {
        uint256 validatorsLength = IStakeFXVault(stFX).getValLength();

        validatorUserDelegations = new ValidatorUserDelegationInfo[](validatorsLength);
        for (uint256 i = 0; i < validatorsLength; i++) {
            (, string memory validatorAddress) = IStakeFXVault(stFX).getValInfo(i);
            
            (, uint256 delegationAmount) = _delegation(validatorAddress, user);
            uint256 allowanceShares = _allowanceShares(validatorAddress, user, stFX);

            validatorUserDelegations[i] = ValidatorUserDelegationInfo({
                validator: validatorAddress,
                delegationAmount: delegationAmount,
                allowanceShares: allowanceShares
            });
        }
    }

    /**************************************** Only Owner Functions ****************************************/

    function updateStFX(
        address _stFX
    ) external onlyOwner() {
        require(_stFX != address(0), "Cannot 0 add");
        require(_stFX != stFX, "Cannot same add");
        stFX = _stFX;
    }

    function recoverToken(
        address token,
        uint256 amount,
        address _recipient
    ) external onlyOwner() {
        require(_recipient != address(0), "Send to zero address");
        IERC20Upgradeable(token).safeTransfer(_recipient, amount);
    }

    function _authorizeUpgrade(
        address
    ) internal override onlyOwner() {} 

    /**************************************************************
     * @dev Initialize the states
     *************************************************************/

    function initialize(address _stFX) public initializer {
        stFX = _stFX;
        __Ownable_init();
        __UUPSUpgradeable_init();
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)

pragma solidity ^0.8.0;

/**
 * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
 */
interface IERC1822ProxiableUpgradeable {
    /**
     * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
     * address.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy.
     */
    function proxiableUUID() external view returns (bytes32);
}
          

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

library Decode {
    function delegate(
        bytes memory data
    ) internal pure returns (uint256, uint256) {
        (uint256 shares, uint256 reward) = abi.decode(data, (uint256, uint256));
        return (shares, reward);
    }

    function undelegate(
        bytes memory data
    ) internal pure returns (uint256, uint256, uint256) {
        (uint256 amount, uint256 reward, uint256 endTime) = abi.decode(
            data,
            (uint256, uint256, uint256)
        );
        return (amount, reward, endTime);
    }

    function redelegate(bytes memory data) internal pure returns (uint256, uint256, uint256) {
        (uint256 _amount, uint256 _reward, uint256 _completionTime) = abi.decode(data, (uint256, uint256, uint256));
        return (_amount, _reward, _completionTime);
    }

    function delegateV2(
        bytes memory data
    ) internal pure returns (bool) {
        (bool _result) = abi.decode(data, (bool));
        return (_result);
    }

    function undelegateV2(
        bytes memory data
    ) internal pure returns (bool) {
        (bool _result) = abi.decode(
            data,
            (bool)
        );
        return (_result);
    }

    function redelegateV2(bytes memory data) internal pure returns (bool) {
        (bool _result) = abi.decode(data, (bool));
        return (_result);
    }

    function withdraw(bytes memory data) internal pure returns (uint256) {
        uint256 reward = abi.decode(data, (uint256));
        return reward;
    }

    function transferShares(bytes memory data) internal pure returns (uint256, uint256) {
        (uint256 token, uint256 reward) = abi.decode(data, (uint256, uint256));
        return (token, reward);
    }

    function transferFromShares(bytes memory data) internal pure returns (uint256, uint256) {
        (uint256 token, uint256 reward) = abi.decode(data, (uint256, uint256));
        return (token, reward);
    }

    function delegation(bytes memory data) internal pure returns (uint256, uint256) {
        (uint256 delegateShare, uint256 delegateAmount) = abi.decode(data, (uint256, uint256));
        return (delegateShare, delegateAmount);
    }

    function delegationRewards(bytes memory data) internal pure returns (uint256) {
        uint256 rewardAmount = abi.decode(data, (uint256));
        return rewardAmount;
    }

    function allowanceShares(bytes memory data) internal pure returns (uint256) {
        uint256 allowanceAmount = abi.decode(data, (uint256));
        return allowanceAmount;
    }

    function ok(
        bool _result,
        bytes memory _data,
        string memory _msg
    ) internal pure {
        if (!_result) {
            string memory errMsg = abi.decode(_data, (string));
            if (bytes(_msg).length < 1) {
                revert(errMsg);
            }
            revert(string(abi.encodePacked(_msg, ": ", errMsg)));
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [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://consensys.net/diligence/blog/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/v0.8.0/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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}
          

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

interface IRewardDistributor {
    function rewardToken() external view returns (address);
    function tokensPerInterval() external view returns (uint256);
    function pendingRewards() external view returns (uint256);
    function distribute() external returns (uint256);
}
          

// SPDX-License-Identifier: UNLICENSED

pragma solidity ^0.8.10;

import {PausableUpgradeable} from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import {ERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
import {IERC20MetadataUpgradeable, IERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/IERC20MetadataUpgradeable.sol";
import {ERC4626Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC4626Upgradeable.sol";
import {MathUpgradeable} from "@openzeppelin/contracts-upgradeable/utils/math/MathUpgradeable.sol";

import {Governable} from "../common/Governable.sol";

abstract contract BaseVault is Governable, PausableUpgradeable, ERC4626Upgradeable {
    using MathUpgradeable for uint256;

    function __BaseVaultInit(address _asset, string memory _name, string memory _symbol, address _owner, address _governor) internal{
        __ERC4626_init(IERC20MetadataUpgradeable(_asset));
        __ERC20_init(_name, _symbol);
        __Pausable_init();
        __AccessControl_init();

        __Governable_init(_owner, _governor);
    }

    // ============================= Revert functions ================================ //
    /**
     * @dev See {openzeppelin-IERC4626-deposit}.
     */
    function deposit(uint256 , address )
        public
        override
        returns (uint256)
    {
        revert("disabled");
    }

    /**
     * @dev See {openzeppelin-IERC4626-mint}.
     */
    function mint(uint256 , address )
        public
        override
        returns (uint256)
    {
        revert("disabled");
    }

    /**
     * @dev See {openzeppelin-IERC4626-withdraw}.
     */
    function withdraw(uint256 , address , address )
        public
        override
        returns (uint256)
    {
        revert("disabled");
    }

    /**
     * @dev See {openzeppelin-IERC4626-redeem}.
     */
    function redeem(uint256 , address , address )
        public
        override
        returns (uint256)
    {
        revert("disabled");
    }


    // ============================= Internal functions ================================ //
    /**
     * @dev Internal conversion function (from assets to shares) with support for rounding direction.
     *
     * Will revert if assets > 0, totalSupply > 0 and totalAssets = 0. That corresponds to a case where any asset
     * would represent an infinite amount of shares.
     */
    function _convertToShares(uint256 assets, MathUpgradeable.Rounding rounding) internal view override returns (uint256 shares) {
        uint256 supply = totalSupply();
        return
            (assets == 0 || supply == 0)
                ? _initialConvertToShares(assets, rounding)
                : assets.mulDiv(supply, totalAssets(), rounding);
    }

    /**
     * @dev Internal conversion function (from assets to shares) to apply when the vault is empty.
     *
     * NOTE: Make sure to keep this function consistent with {_initialConvertToAssets} when overriding it.
     */
    function _initialConvertToShares(
        uint256 assets,
        MathUpgradeable.Rounding /*rounding*/
    ) internal view virtual returns (uint256 shares) {
        return assets;
    }

    /**
     * @dev Internal conversion function (from shares to assets) with support for rounding direction.
     */
    function _convertToAssets(uint256 shares, MathUpgradeable.Rounding rounding) internal view override returns (uint256 assets) {
        uint256 supply = totalSupply();
        return
            (supply == 0) ? _initialConvertToAssets(shares, rounding) : shares.mulDiv(totalAssets(), supply, rounding);
    }

    /**
     * @dev Internal conversion function (from shares to assets) to apply when the vault is empty.
     *
     * NOTE: Make sure to keep this function consistent with {_initialConvertToShares} when overriding it.
     */
    function _initialConvertToAssets(
        uint256 shares,
        MathUpgradeable.Rounding /*rounding*/
    ) internal view virtual returns (uint256 assets) {
        return shares;
    }

    // ============================= Governable functions ================================ //

    function pause() public onlyRole(OWNER_ROLE) {
        _pause();
    }

    function unpause() public onlyRole(OWNER_ROLE) {
        _unpause();
    }

    /**
     * @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 v4.9.0) (security/ReentrancyGuard.sol)

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

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    function __ReentrancyGuard_init() internal onlyInitializing {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal onlyInitializing {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == _ENTERED;
    }

    /**
     * @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 v4.9.0) (access/AccessControl.sol)

pragma solidity ^0.8.0;

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

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

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

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

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

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

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

    /**
     * @dev Revert with a standard message if `_msgSender()` is missing `role`.
     * Overriding this function changes the behavior of the {onlyRole} modifier.
     *
     * Format of the revert message is described in {_checkRole}.
     *
     * _Available since v4.6._
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }

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

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

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

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

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

        _revokeRole(role, account);
    }

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

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

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMathUpgradeable {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC4626.sol)

pragma solidity ^0.8.0;

import "../token/ERC20/IERC20Upgradeable.sol";
import "../token/ERC20/extensions/IERC20MetadataUpgradeable.sol";

/**
 * @dev Interface of the ERC4626 "Tokenized Vault Standard", as defined in
 * https://eips.ethereum.org/EIPS/eip-4626[ERC-4626].
 *
 * _Available since v4.7._
 */
interface IERC4626Upgradeable is IERC20Upgradeable, IERC20MetadataUpgradeable {
    event Deposit(address indexed sender, address indexed owner, uint256 assets, uint256 shares);

    event Withdraw(
        address indexed sender,
        address indexed receiver,
        address indexed owner,
        uint256 assets,
        uint256 shares
    );

    /**
     * @dev Returns the address of the underlying token used for the Vault for accounting, depositing, and withdrawing.
     *
     * - MUST be an ERC-20 token contract.
     * - MUST NOT revert.
     */
    function asset() external view returns (address assetTokenAddress);

    /**
     * @dev Returns the total amount of the underlying asset that is “managed” by Vault.
     *
     * - SHOULD include any compounding that occurs from yield.
     * - MUST be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT revert.
     */
    function totalAssets() external view returns (uint256 totalManagedAssets);

    /**
     * @dev Returns the amount of shares that the Vault would exchange for the amount of assets provided, in an ideal
     * scenario where all the conditions are met.
     *
     * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT show any variations depending on the caller.
     * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
     * - MUST NOT revert.
     *
     * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
     * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
     * from.
     */
    function convertToShares(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Returns the amount of assets that the Vault would exchange for the amount of shares provided, in an ideal
     * scenario where all the conditions are met.
     *
     * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
     * - MUST NOT show any variations depending on the caller.
     * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
     * - MUST NOT revert.
     *
     * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
     * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
     * from.
     */
    function convertToAssets(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Returns the maximum amount of the underlying asset that can be deposited into the Vault for the receiver,
     * through a deposit call.
     *
     * - MUST return a limited value if receiver is subject to some deposit limit.
     * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of assets that may be deposited.
     * - MUST NOT revert.
     */
    function maxDeposit(address receiver) external view returns (uint256 maxAssets);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their deposit at the current block, given
     * current on-chain conditions.
     *
     * - MUST return as close to and no more than the exact amount of Vault shares that would be minted in a deposit
     *   call in the same transaction. I.e. deposit should return the same or more shares as previewDeposit if called
     *   in the same transaction.
     * - MUST NOT account for deposit limits like those returned from maxDeposit and should always act as though the
     *   deposit would be accepted, regardless if the user has enough tokens approved, etc.
     * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToShares and previewDeposit SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by depositing.
     */
    function previewDeposit(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens.
     *
     * - MUST emit the Deposit event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   deposit execution, and are accounted for during deposit.
     * - MUST revert if all of assets cannot be deposited (due to deposit limit being reached, slippage, the user not
     *   approving enough underlying tokens to the Vault contract, etc).
     *
     * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
     */
    function deposit(uint256 assets, address receiver) external returns (uint256 shares);

    /**
     * @dev Returns the maximum amount of the Vault shares that can be minted for the receiver, through a mint call.
     * - MUST return a limited value if receiver is subject to some mint limit.
     * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of shares that may be minted.
     * - MUST NOT revert.
     */
    function maxMint(address receiver) external view returns (uint256 maxShares);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their mint at the current block, given
     * current on-chain conditions.
     *
     * - MUST return as close to and no fewer than the exact amount of assets that would be deposited in a mint call
     *   in the same transaction. I.e. mint should return the same or fewer assets as previewMint if called in the
     *   same transaction.
     * - MUST NOT account for mint limits like those returned from maxMint and should always act as though the mint
     *   would be accepted, regardless if the user has enough tokens approved, etc.
     * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToAssets and previewMint SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by minting.
     */
    function previewMint(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Mints exactly shares Vault shares to receiver by depositing amount of underlying tokens.
     *
     * - MUST emit the Deposit event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the mint
     *   execution, and are accounted for during mint.
     * - MUST revert if all of shares cannot be minted (due to deposit limit being reached, slippage, the user not
     *   approving enough underlying tokens to the Vault contract, etc).
     *
     * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
     */
    function mint(uint256 shares, address receiver) external returns (uint256 assets);

    /**
     * @dev Returns the maximum amount of the underlying asset that can be withdrawn from the owner balance in the
     * Vault, through a withdraw call.
     *
     * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
     * - MUST NOT revert.
     */
    function maxWithdraw(address owner) external view returns (uint256 maxAssets);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their withdrawal at the current block,
     * given current on-chain conditions.
     *
     * - MUST return as close to and no fewer than the exact amount of Vault shares that would be burned in a withdraw
     *   call in the same transaction. I.e. withdraw should return the same or fewer shares as previewWithdraw if
     *   called
     *   in the same transaction.
     * - MUST NOT account for withdrawal limits like those returned from maxWithdraw and should always act as though
     *   the withdrawal would be accepted, regardless if the user has enough shares, etc.
     * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToShares and previewWithdraw SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by depositing.
     */
    function previewWithdraw(uint256 assets) external view returns (uint256 shares);

    /**
     * @dev Burns shares from owner and sends exactly assets of underlying tokens to receiver.
     *
     * - MUST emit the Withdraw event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   withdraw execution, and are accounted for during withdraw.
     * - MUST revert if all of assets cannot be withdrawn (due to withdrawal limit being reached, slippage, the owner
     *   not having enough shares, etc).
     *
     * Note that some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
     * Those methods should be performed separately.
     */
    function withdraw(uint256 assets, address receiver, address owner) external returns (uint256 shares);

    /**
     * @dev Returns the maximum amount of Vault shares that can be redeemed from the owner balance in the Vault,
     * through a redeem call.
     *
     * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
     * - MUST return balanceOf(owner) if owner is not subject to any withdrawal limit or timelock.
     * - MUST NOT revert.
     */
    function maxRedeem(address owner) external view returns (uint256 maxShares);

    /**
     * @dev Allows an on-chain or off-chain user to simulate the effects of their redeemption at the current block,
     * given current on-chain conditions.
     *
     * - MUST return as close to and no more than the exact amount of assets that would be withdrawn in a redeem call
     *   in the same transaction. I.e. redeem should return the same or more assets as previewRedeem if called in the
     *   same transaction.
     * - MUST NOT account for redemption limits like those returned from maxRedeem and should always act as though the
     *   redemption would be accepted, regardless if the user has enough shares, etc.
     * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
     * - MUST NOT revert.
     *
     * NOTE: any unfavorable discrepancy between convertToAssets and previewRedeem SHOULD be considered slippage in
     * share price or some other type of condition, meaning the depositor will lose assets by redeeming.
     */
    function previewRedeem(uint256 shares) external view returns (uint256 assets);

    /**
     * @dev Burns exactly shares from owner and sends assets of underlying tokens to receiver.
     *
     * - MUST emit the Withdraw event.
     * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
     *   redeem execution, and are accounted for during redeem.
     * - MUST revert if all of shares cannot be redeemed (due to withdrawal limit being reached, slippage, the owner
     *   not having enough shares, etc).
     *
     * NOTE: some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
     * Those methods should be performed separately.
     */
    function redeem(uint256 shares, address receiver, address owner) external returns (uint256 assets);
}
          

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;

import {AccessControlUpgradeable} from "@openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol";

abstract contract Governable is AccessControlUpgradeable {
    bytes32 public constant OWNER_ROLE = bytes32("OWNER_ROLE");
    bytes32 public constant GOVERNOR_ROLE = bytes32("GOVERNOR_ROLE");
    bytes32 public constant OPERATOR_ROLE = bytes32("OPERATOR_ROLE");       // only contract address

    function __Governable_init(address _owner, address _governor) internal {
        // Assign roles to the sender.
        _grantRole(OWNER_ROLE, _owner);
        _grantRole(GOVERNOR_ROLE, _governor);

        // Set OWNER_ROLE as the admin of all roles.
        _setRoleAdmin(OWNER_ROLE, OWNER_ROLE);
        _setRoleAdmin(GOVERNOR_ROLE, OWNER_ROLE);
        _setRoleAdmin(OPERATOR_ROLE, OWNER_ROLE);
    }

    /**
     * @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 v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20PermitUpgradeable {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
          

// SPDX-License-Identifier: Apache-2.0

pragma solidity ^0.8.0;

interface IStakeFXVault {

    function sendVestedFX(uint256 safeAmount) external;

    function updateRewards() external;

    function getValLength() external view returns (uint256);

    function getValInfo(uint256 index) external view returns (uint256, string memory);

    function stake(uint256 amount, bool native) external payable;

    function unstake(uint256 amount) external;

    function entrustDelegatedShare(string memory val, uint256 amount) external;

    function compound() external;

    function claim(address receiver) external returns (uint256);
}
          

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

import {SafeMathUpgradeable} from "@openzeppelin/contracts-upgradeable/utils/math/SafeMathUpgradeable.sol";
import {IERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import {SafeERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import {ReentrancyGuardUpgradeable} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";

import "./interfaces/IRewardDistributor.sol";
import "./interfaces/IStakeFXVault.sol";
import "./common/Governable.sol";

contract RewardDistributor is Initializable, UUPSUpgradeable, IRewardDistributor, ReentrancyGuardUpgradeable, Governable {
    using SafeMathUpgradeable for uint256;
    using SafeERC20Upgradeable for IERC20Upgradeable;

    address public override rewardToken;
    uint256 public override tokensPerInterval;
    uint256 public lastDistributionTime;
    address public rewardTracker;

    event Distribute(uint256 amount);
    event TokensPerIntervalChange(uint256 amount);

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    /**************************************** Core Functions ****************************************/

    function distribute() external override returns (uint256) {
        require(msg.sender == rewardTracker, "RewardDistributor: invalid msg.sender");
        uint256 amount = pendingRewards();
        if (amount == 0) { return 0; }

        lastDistributionTime = block.timestamp;

        uint256 balance = IERC20Upgradeable(rewardToken).balanceOf(address(this));
        if (amount > balance) { amount = balance; }

        IERC20Upgradeable(rewardToken).safeTransfer(msg.sender, amount);

        emit Distribute(amount);
        return amount;
    }

    /**************************************** View Functions ****************************************/

    function pendingRewards() public view override returns (uint256) {
        if (block.timestamp == lastDistributionTime) {
            return 0;
        }

        uint256 timeDiff = block.timestamp.sub(lastDistributionTime);
        return tokensPerInterval.mul(timeDiff);
    }

    /**************************************** Only Admin/Governor Functions ****************************************/

    function updateLastDistributionTime() external onlyRole(GOVERNOR_ROLE) {
        lastDistributionTime = block.timestamp;
    }

    function setTokensPerInterval(uint256 _amount) external onlyRole(GOVERNOR_ROLE) {
        require(lastDistributionTime != 0, "RewardDistributor: invalid lastDistributionTime");
        IStakeFXVault(rewardTracker).updateRewards();
        tokensPerInterval = _amount;
        emit TokensPerIntervalChange(_amount);
    }



    /**************************************** Only Owner Functions ****************************************/

    /**
     * @dev Need to make sure all rewardTracker contracts fully migrate rewardToken to new rewardToken after update this contract rewardToken address
     */
    function updateRewardToken(address _rewardToken) external onlyRole(OWNER_ROLE) {
        rewardToken = _rewardToken;
    }

    function recoverToken(
        address token,
        uint256 amount,
        address _recipient
    ) external onlyRole(OWNER_ROLE) {
        require(_recipient != address(0), "Send to zero address");
        IERC20Upgradeable(token).safeTransfer(_recipient, amount);
    }

    function _authorizeUpgrade(
        address
    ) internal override onlyRole(OWNER_ROLE) {} 

    /**************************************************************
     * @dev Initialize the states
     *************************************************************/    
    function initialize(
        address _rewardToken, address _rewardTracker, address _owner, address _governor
    ) public initializer {
        rewardToken = _rewardToken;
        rewardTracker = _rewardTracker;
        
        __Governable_init(_owner, _governor);
        __UUPSUpgradeable_init();
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/ERC4626.sol)

pragma solidity ^0.8.0;

import "../ERC20Upgradeable.sol";
import "../utils/SafeERC20Upgradeable.sol";
import "../../../interfaces/IERC4626Upgradeable.sol";
import "../../../utils/math/MathUpgradeable.sol";
import "../../../proxy/utils/Initializable.sol";

/**
 * @dev Implementation of the ERC4626 "Tokenized Vault Standard" as defined in
 * https://eips.ethereum.org/EIPS/eip-4626[EIP-4626].
 *
 * This extension allows the minting and burning of "shares" (represented using the ERC20 inheritance) in exchange for
 * underlying "assets" through standardized {deposit}, {mint}, {redeem} and {burn} workflows. This contract extends
 * the ERC20 standard. Any additional extensions included along it would affect the "shares" token represented by this
 * contract and not the "assets" token which is an independent contract.
 *
 * [CAUTION]
 * ====
 * In empty (or nearly empty) ERC-4626 vaults, deposits are at high risk of being stolen through frontrunning
 * with a "donation" to the vault that inflates the price of a share. This is variously known as a donation or inflation
 * attack and is essentially a problem of slippage. Vault deployers can protect against this attack by making an initial
 * deposit of a non-trivial amount of the asset, such that price manipulation becomes infeasible. Withdrawals may
 * similarly be affected by slippage. Users can protect against this attack as well as unexpected slippage in general by
 * verifying the amount received is as expected, using a wrapper that performs these checks such as
 * https://github.com/fei-protocol/ERC4626#erc4626router-and-base[ERC4626Router].
 *
 * Since v4.9, this implementation uses virtual assets and shares to mitigate that risk. The `_decimalsOffset()`
 * corresponds to an offset in the decimal representation between the underlying asset's decimals and the vault
 * decimals. This offset also determines the rate of virtual shares to virtual assets in the vault, which itself
 * determines the initial exchange rate. While not fully preventing the attack, analysis shows that the default offset
 * (0) makes it non-profitable, as a result of the value being captured by the virtual shares (out of the attacker's
 * donation) matching the attacker's expected gains. With a larger offset, the attack becomes orders of magnitude more
 * expensive than it is profitable. More details about the underlying math can be found
 * xref:erc4626.adoc#inflation-attack[here].
 *
 * The drawback of this approach is that the virtual shares do capture (a very small) part of the value being accrued
 * to the vault. Also, if the vault experiences losses, the users try to exit the vault, the virtual shares and assets
 * will cause the first user to exit to experience reduced losses in detriment to the last users that will experience
 * bigger losses. Developers willing to revert back to the pre-v4.9 behavior just need to override the
 * `_convertToShares` and `_convertToAssets` functions.
 *
 * To learn more, check out our xref:ROOT:erc4626.adoc[ERC-4626 guide].
 * ====
 *
 * _Available since v4.7._
 */
abstract contract ERC4626Upgradeable is Initializable, ERC20Upgradeable, IERC4626Upgradeable {
    using MathUpgradeable for uint256;

    IERC20Upgradeable private _asset;
    uint8 private _underlyingDecimals;

    /**
     * @dev Set the underlying asset contract. This must be an ERC20-compatible contract (ERC20 or ERC777).
     */
    function __ERC4626_init(IERC20Upgradeable asset_) internal onlyInitializing {
        __ERC4626_init_unchained(asset_);
    }

    function __ERC4626_init_unchained(IERC20Upgradeable asset_) internal onlyInitializing {
        (bool success, uint8 assetDecimals) = _tryGetAssetDecimals(asset_);
        _underlyingDecimals = success ? assetDecimals : 18;
        _asset = asset_;
    }

    /**
     * @dev Attempts to fetch the asset decimals. A return value of false indicates that the attempt failed in some way.
     */
    function _tryGetAssetDecimals(IERC20Upgradeable asset_) private view returns (bool, uint8) {
        (bool success, bytes memory encodedDecimals) = address(asset_).staticcall(
            abi.encodeWithSelector(IERC20MetadataUpgradeable.decimals.selector)
        );
        if (success && encodedDecimals.length >= 32) {
            uint256 returnedDecimals = abi.decode(encodedDecimals, (uint256));
            if (returnedDecimals <= type(uint8).max) {
                return (true, uint8(returnedDecimals));
            }
        }
        return (false, 0);
    }

    /**
     * @dev Decimals are computed by adding the decimal offset on top of the underlying asset's decimals. This
     * "original" value is cached during construction of the vault contract. If this read operation fails (e.g., the
     * asset has not been created yet), a default of 18 is used to represent the underlying asset's decimals.
     *
     * See {IERC20Metadata-decimals}.
     */
    function decimals() public view virtual override(IERC20MetadataUpgradeable, ERC20Upgradeable) returns (uint8) {
        return _underlyingDecimals + _decimalsOffset();
    }

    /** @dev See {IERC4626-asset}. */
    function asset() public view virtual override returns (address) {
        return address(_asset);
    }

    /** @dev See {IERC4626-totalAssets}. */
    function totalAssets() public view virtual override returns (uint256) {
        return _asset.balanceOf(address(this));
    }

    /** @dev See {IERC4626-convertToShares}. */
    function convertToShares(uint256 assets) public view virtual override returns (uint256) {
        return _convertToShares(assets, MathUpgradeable.Rounding.Down);
    }

    /** @dev See {IERC4626-convertToAssets}. */
    function convertToAssets(uint256 shares) public view virtual override returns (uint256) {
        return _convertToAssets(shares, MathUpgradeable.Rounding.Down);
    }

    /** @dev See {IERC4626-maxDeposit}. */
    function maxDeposit(address) public view virtual override returns (uint256) {
        return type(uint256).max;
    }

    /** @dev See {IERC4626-maxMint}. */
    function maxMint(address) public view virtual override returns (uint256) {
        return type(uint256).max;
    }

    /** @dev See {IERC4626-maxWithdraw}. */
    function maxWithdraw(address owner) public view virtual override returns (uint256) {
        return _convertToAssets(balanceOf(owner), MathUpgradeable.Rounding.Down);
    }

    /** @dev See {IERC4626-maxRedeem}. */
    function maxRedeem(address owner) public view virtual override returns (uint256) {
        return balanceOf(owner);
    }

    /** @dev See {IERC4626-previewDeposit}. */
    function previewDeposit(uint256 assets) public view virtual override returns (uint256) {
        return _convertToShares(assets, MathUpgradeable.Rounding.Down);
    }

    /** @dev See {IERC4626-previewMint}. */
    function previewMint(uint256 shares) public view virtual override returns (uint256) {
        return _convertToAssets(shares, MathUpgradeable.Rounding.Up);
    }

    /** @dev See {IERC4626-previewWithdraw}. */
    function previewWithdraw(uint256 assets) public view virtual override returns (uint256) {
        return _convertToShares(assets, MathUpgradeable.Rounding.Up);
    }

    /** @dev See {IERC4626-previewRedeem}. */
    function previewRedeem(uint256 shares) public view virtual override returns (uint256) {
        return _convertToAssets(shares, MathUpgradeable.Rounding.Down);
    }

    /** @dev See {IERC4626-deposit}. */
    function deposit(uint256 assets, address receiver) public virtual override returns (uint256) {
        require(assets <= maxDeposit(receiver), "ERC4626: deposit more than max");

        uint256 shares = previewDeposit(assets);
        _deposit(_msgSender(), receiver, assets, shares);

        return shares;
    }

    /** @dev See {IERC4626-mint}.
     *
     * As opposed to {deposit}, minting is allowed even if the vault is in a state where the price of a share is zero.
     * In this case, the shares will be minted without requiring any assets to be deposited.
     */
    function mint(uint256 shares, address receiver) public virtual override returns (uint256) {
        require(shares <= maxMint(receiver), "ERC4626: mint more than max");

        uint256 assets = previewMint(shares);
        _deposit(_msgSender(), receiver, assets, shares);

        return assets;
    }

    /** @dev See {IERC4626-withdraw}. */
    function withdraw(uint256 assets, address receiver, address owner) public virtual override returns (uint256) {
        require(assets <= maxWithdraw(owner), "ERC4626: withdraw more than max");

        uint256 shares = previewWithdraw(assets);
        _withdraw(_msgSender(), receiver, owner, assets, shares);

        return shares;
    }

    /** @dev See {IERC4626-redeem}. */
    function redeem(uint256 shares, address receiver, address owner) public virtual override returns (uint256) {
        require(shares <= maxRedeem(owner), "ERC4626: redeem more than max");

        uint256 assets = previewRedeem(shares);
        _withdraw(_msgSender(), receiver, owner, assets, shares);

        return assets;
    }

    /**
     * @dev Internal conversion function (from assets to shares) with support for rounding direction.
     */
    function _convertToShares(uint256 assets, MathUpgradeable.Rounding rounding) internal view virtual returns (uint256) {
        return assets.mulDiv(totalSupply() + 10 ** _decimalsOffset(), totalAssets() + 1, rounding);
    }

    /**
     * @dev Internal conversion function (from shares to assets) with support for rounding direction.
     */
    function _convertToAssets(uint256 shares, MathUpgradeable.Rounding rounding) internal view virtual returns (uint256) {
        return shares.mulDiv(totalAssets() + 1, totalSupply() + 10 ** _decimalsOffset(), rounding);
    }

    /**
     * @dev Deposit/mint common workflow.
     */
    function _deposit(address caller, address receiver, uint256 assets, uint256 shares) internal virtual {
        // If _asset is ERC777, `transferFrom` can trigger a reentrancy BEFORE the transfer happens through the
        // `tokensToSend` hook. On the other hand, the `tokenReceived` hook, that is triggered after the transfer,
        // calls the vault, which is assumed not malicious.
        //
        // Conclusion: we need to do the transfer before we mint so that any reentrancy would happen before the
        // assets are transferred and before the shares are minted, which is a valid state.
        // slither-disable-next-line reentrancy-no-eth
        SafeERC20Upgradeable.safeTransferFrom(_asset, caller, address(this), assets);
        _mint(receiver, shares);

        emit Deposit(caller, receiver, assets, shares);
    }

    /**
     * @dev Withdraw/redeem common workflow.
     */
    function _withdraw(
        address caller,
        address receiver,
        address owner,
        uint256 assets,
        uint256 shares
    ) internal virtual {
        if (caller != owner) {
            _spendAllowance(owner, caller, shares);
        }

        // If _asset is ERC777, `transfer` can trigger a reentrancy AFTER the transfer happens through the
        // `tokensReceived` hook. On the other hand, the `tokensToSend` hook, that is triggered before the transfer,
        // calls the vault, which is assumed not malicious.
        //
        // Conclusion: we need to do the transfer after the burn so that any reentrancy would happen after the
        // shares are burned and after the assets are transferred, which is a valid state.
        _burn(owner, shares);
        SafeERC20Upgradeable.safeTransfer(_asset, receiver, assets);

        emit Withdraw(caller, receiver, owner, assets, shares);
    }

    function _decimalsOffset() internal view virtual returns (uint8) {
        return 0;
    }

    /**
     * @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

pragma solidity ^0.8.18;

library Encode {
    function delegate(
        string memory _validator
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("delegate(string)", _validator);
    }

    function undelegate(
        string memory _validator,
        uint256 _shares
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("undelegate(string,uint256)", _validator, _shares);
    }

    function redelegate(
        string memory _valSrc,
        string memory _valDst,
        uint256 _shares
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("redelegate(string,string,uint256)", _valSrc, _valDst, _shares);
    }

    function delegateV2(
        string memory _validator,
        uint256 _amount
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("delegate(string, uint256)", _validator, _amount);
    }

    function undelegateV2(
        string memory _validator,
        uint256 _amount
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("undelegate(string,uint256)", _validator, _amount);
    }

    function redelegateV2(
        string memory _valSrc,
        string memory _valDst,
        uint256 _amount
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("redelegate(string,string,uint256)", _valSrc, _valDst, _amount);
    }

    function withdraw(
        string memory _validator
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("withdraw(string)", _validator);
    }

    function transferShares(
        string memory _validator,
        address _to,
        uint256 _shares
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("transferFromShares(string,address,uint256)", _validator, _to, _shares);
    }

    function transferFromShares(
        string memory _validator,
        address _from,
        address _to,
        uint256 _shares
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("transferFromShares(string,address,address,uint256)", _validator, _from, _to, _shares);
    }

    function delegation(
        string memory _validator,
        address _delegate
    ) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("delegation(string,address)", _validator, _delegate);
    }

    function delegationRewards(
        string memory _validator, 
        address _delegate) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("delegationRewards(string,address)", _validator, _delegate);
    }

    function allowanceShares(
        string memory _validator, 
        address _owner,
        address _spender) internal pure returns (bytes memory) {
        return abi.encodeWithSignature("allowanceShares(string,address,address)", _validator, _owner, _spender);
    }
}
          

// SPDX-License-Identifier: UNLICENSED

pragma solidity ^0.8.10;

import {Encode} from "../libraries/Encode.sol";
import {Decode} from "../libraries/Decode.sol";
import {IPrecompileStaking} from "../interfaces/IPrecompileStaking.sol";

/**
 * @title PrecompileStaking
 *
 * @dev Interface to interact to network precompile staking contract functions.
 */
abstract contract PrecompileStaking {

    address private constant _stakingAddress = address(0x0000000000000000000000000000000000001003);

    /**************************************** Precompile Staking Internal Functions ****************************************/

    function _delegate(string memory _val, uint256 _amount) internal returns (uint256, uint256) {
        (bool result, bytes memory data) = _stakingAddress.call{value: _amount}(Encode.delegate(_val));
        Decode.ok(result, data, "delegate failed");

        return Decode.delegate(data);
    }

    function _undelegate(string memory _val, uint256 _shares) internal returns (uint256, uint256, uint256) {
        (bool result, bytes memory data) = _stakingAddress.call(Encode.undelegate(_val, _shares));
        Decode.ok(result, data, "undelegate failed");

        return Decode.undelegate(data);
    }

    function _redelegate(string memory _valSrc, string memory _valDst, uint256 _shares) internal returns (uint256, uint256, uint256) {
        (bool result, bytes memory data) = _stakingAddress.call(Encode.redelegate(_valSrc, _valDst, _shares));
        Decode.ok(result, data, "redelegate failed");

        return Decode.redelegate(data);
    }

    function _delegateV2(string memory _val, uint256 _amount) internal returns (bool _result) {
        require(address(this).balance >= _amount, "insufficient balance");
        return IPrecompileStaking(_stakingAddress).delegateV2(_val, _amount);
    }

    function _undelegateV2(string memory _val, uint256 _amount) internal returns (bool _result) {
        return IPrecompileStaking(_stakingAddress).undelegateV2(_val,_amount);
    }

    function _redelegateV2(string memory _valSrc, string memory _valDst, uint256 _amount) internal returns (bool _result) {
        return IPrecompileStaking(_stakingAddress).redelegateV2(_valSrc, _valDst, _amount);
    }

    function _withdraw(string memory _val) internal returns (uint256) {
        (bool result, bytes memory data) = _stakingAddress.call(Encode.withdraw(_val));
        Decode.ok(result, data, "withdraw failed");

        return Decode.withdraw(data);
    }

    function _transferShares(string memory _val, address _to, uint256 _shares) internal returns (uint256, uint256) {
        (bool result, bytes memory data) = _stakingAddress.call(Encode.transferShares(_val, _to, _shares));
        Decode.ok(result, data, "transferShares failed");

        return Decode.transferShares(data);
    }

    function _transferFromShares(string memory _val, address _from, address _to, uint256 _shares) internal returns (uint256, uint256) {
        (bool result, bytes memory data) = _stakingAddress.call(Encode.transferFromShares(_val, _from, _to, _shares));
        Decode.ok(result, data, "transferFromShares failed");

        return Decode.transferFromShares(data);
    }

    function _delegation(string memory _val, address _del) internal view returns (uint256, uint256) {
        (bool result, bytes memory data) = _stakingAddress.staticcall(Encode.delegation(_val, _del));
        Decode.ok(result, data, "delegation failed");

        return Decode.delegation(data);
    }

    function _delegationRewards(string memory _val, address _del) internal view returns (uint256) {
        (bool result, bytes memory data) = _stakingAddress.staticcall(Encode.delegationRewards(_val, _del));
        Decode.ok(result, data, "delegationRewards failed");

        return Decode.delegationRewards(data);
    }

    function _allowanceShares(string memory _val, address _owner, address _spender) internal view returns (uint256) {
        (bool result, bytes memory data) = _stakingAddress.staticcall(Encode.allowanceShares(_val, _owner, _spender));
        Decode.ok(result, data, "allowanceShares failed");

        return Decode.allowanceShares(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[49] private __gap;
}
          

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

pragma solidity ^0.8.0;

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

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC1967.sol)

pragma solidity ^0.8.0;

/**
 * @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
 *
 * _Available since v4.8.3._
 */
interface IERC1967Upgradeable {
    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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