// File: contracts/lpaccount/LpAccountV2.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {
    IAssetAllocation,
    IERC20,
    IEmergencyExit
} from "contracts/common/Imports.sol";
import {
    Address,
    EnumerableSet,
    NamedAddressSet,
    SafeERC20,
    SafeMath
} from "contracts/libraries/Imports.sol";
import {
    Initializable,
    ReentrancyGuardUpgradeSafe,
    AccessControlUpgradeSafe
} from "contracts/proxy/Imports.sol";
import {ILiquidityPoolV2} from "contracts/pool/Imports.sol";
import {IAddressRegistryV2} from "contracts/registry/Imports.sol";
import {
    IAssetAllocationRegistry,
    IErc20Allocation,
    Erc20AllocationConstants
} from "contracts/tvl/Imports.sol";

import {
    IZap,
    ISwap,
    ILpAccountV2,
    IZapRegistry,
    ISwapRegistry,
    IStableSwap3Pool,
    IRewardFeeRegistry
} from "./Imports.sol";

import {ILockingOracle} from "contracts/oracle/Imports.sol";

contract LpAccountV2 is
    Initializable,
    AccessControlUpgradeSafe,
    ReentrancyGuardUpgradeSafe,
    ILpAccountV2,
    IZapRegistry,
    ISwapRegistry,
    Erc20AllocationConstants,
    IEmergencyExit,
    IRewardFeeRegistry
{
    using Address for address;
    using SafeERC20 for IERC20;
    using SafeMath for uint256;
    using NamedAddressSet for NamedAddressSet.ZapSet;
    using NamedAddressSet for NamedAddressSet.SwapSet;
    using EnumerableSet for EnumerableSet.AddressSet;

    IStableSwap3Pool private constant _STABLE_SWAP_3POOL =
        IStableSwap3Pool(0xbEbc44782C7dB0a1A60Cb6fe97d0b483032FF1C7);
    uint256 private constant _DEFAULT_LOCK_PERIOD = 135;

    /**
     * Begin storage variables
     */

    /** V1 storage */

    IAddressRegistryV2 public addressRegistry;
    uint256 public lockPeriod;

    NamedAddressSet.ZapSet private _zaps;
    NamedAddressSet.SwapSet private _swaps;

    /** V2 storage */

    /** @dev reward tokens to deduct fees on claim */
    EnumerableSet.AddressSet private _rewardTokens;
    /** @dev reward token fees in basis points */
    mapping(address => uint256) public rewardFee;

    /**
     * End storage variables
     */

    /** @notice Log when the address registry is changed */
    event AddressRegistryChanged(address);

    /** @notice Log when the lock period is changed */
    event LockPeriodChanged(uint256);

    /**
     * @dev Since the proxy delegate calls to this "logic" contract, any
     * storage set by the logic contract's constructor during deploy is
     * disregarded and this function is needed to initialize the proxy
     * contract's storage according to this contract's layout.
     *
     * Since storage is not set yet, there is no simple way to protect
     * calling this function with owner modifiers.  Thus the OpenZeppelin
     * `initializer` modifier protects this function from being called
     * repeatedly.  It should be called during the deployment so that
     * it cannot be called by someone else later.
     */
    function initialize(address addressRegistry_) external initializer {
        // initialize ancestor storage
        __Context_init_unchained();
        __AccessControl_init_unchained();
        __ReentrancyGuard_init_unchained();

        // initialize impl-specific storage
        _setAddressRegistry(addressRegistry_);
        _setupRole(DEFAULT_ADMIN_ROLE, addressRegistry.emergencySafeAddress());
        _setupRole(EMERGENCY_ROLE, addressRegistry.emergencySafeAddress());
        _setupRole(ADMIN_ROLE, addressRegistry.adminSafeAddress());
        _setupRole(LP_ROLE, addressRegistry.lpSafeAddress());
        _setupRole(CONTRACT_ROLE, addressRegistry.mAptAddress());

        lockPeriod = _DEFAULT_LOCK_PERIOD;
    }

    /**
     * @dev Note the `initializer` modifier can only be used once in the entire
     * contract, so we can't use it here.  Instead, we protect the upgrade init
     * with the `onlyProxyAdmin` modifier, which checks `msg.sender` against the
     * proxy admin slot defined in EIP-1967. This will only allow the proxy admin
     * to call this function during upgrades.
     */
    // solhint-disable-next-line no-empty-blocks
    function initializeUpgrade() external virtual nonReentrant onlyProxyAdmin {}

    /**
     * @notice Sets the address registry
     * @param addressRegistry_ the address of the registry
     */
    function emergencySetAddressRegistry(address addressRegistry_)
        external
        nonReentrant
        onlyEmergencyRole
    {
        _setAddressRegistry(addressRegistry_);
    }

    /**
     * @notice Set the lock period
     * @param lockPeriod_ The new lock period
     */
    function setLockPeriod(uint256 lockPeriod_)
        external
        nonReentrant
        onlyAdminRole
    {
        lockPeriod = lockPeriod_;
        emit LockPeriodChanged(lockPeriod_);
    }

    function deployStrategy(string calldata name, uint256[] calldata amounts)
        external
        override
        nonReentrant
        onlyLpRole
    {
        IZap zap = _zaps.get(name);
        require(address(zap) != address(0), "INVALID_NAME");

        bool isAssetAllocationRegistered =
            _checkAllocationRegistrations(zap.assetAllocations());
        require(isAssetAllocationRegistered, "MISSING_ASSET_ALLOCATIONS");

        bool isErc20TokenRegistered =
            _checkErc20Registrations(zap.erc20Allocations());
        require(isErc20TokenRegistered, "MISSING_ERC20_ALLOCATIONS");

        address(zap).functionDelegateCall(
            abi.encodeWithSelector(IZap.deployLiquidity.selector, amounts)
        );
        _lockOracleAdapter(lockPeriod);
    }

    function unwindStrategy(
        string calldata name,
        uint256 amount,
        uint8 index
    ) external override nonReentrant onlyLpRole {
        address zap = address(_zaps.get(name));
        require(zap != address(0), "INVALID_NAME");
        zap.functionDelegateCall(
            abi.encodeWithSelector(IZap.unwindLiquidity.selector, amount, index)
        );
        _lockOracleAdapter(lockPeriod);
    }

    function registerZap(IZap zap)
        external
        override
        nonReentrant
        onlyAdminRole
    {
        _zaps.add(zap);

        emit ZapRegistered(zap);
    }

    function removeZap(string calldata name)
        external
        override
        nonReentrant
        onlyAdminRole
    {
        _zaps.remove(name);

        emit ZapRemoved(name);
    }

    function transferToPool(address pool, uint256 amount)
        external
        override
        nonReentrant
        onlyContractRole
    {
        IERC20 underlyer = ILiquidityPoolV2(pool).underlyer();
        underlyer.safeTransfer(pool, amount);
    }

    function swap(
        string calldata name,
        uint256 amount,
        uint256 minAmount
    ) external override nonReentrant onlyLpRole {
        ISwap swap_ = _swaps.get(name);
        require(address(swap_) != address(0), "INVALID_NAME");

        bool isErc20TokenRegistered =
            _checkErc20Registrations(swap_.erc20Allocations());

        require(isErc20TokenRegistered, "MISSING_ERC20_ALLOCATIONS");

        address(swap_).functionDelegateCall(
            abi.encodeWithSelector(ISwap.swap.selector, amount, minAmount)
        );
        _lockOracleAdapter(lockPeriod);
    }

    function registerSwap(ISwap swap_)
        external
        override
        nonReentrant
        onlyAdminRole
    {
        _swaps.add(swap_);

        emit SwapRegistered(swap_);
    }

    function removeSwap(string calldata name)
        external
        override
        nonReentrant
        onlyAdminRole
    {
        _swaps.remove(name);

        emit SwapRemoved(name);
    }

    /**
     * @notice Swap stablecoins with the Curve 3pool
     * @param inTokenIndex Token index for the input token
     * @param outTokenIndex Token index for the output token
     * @param amount The amount of token to swap
     * @param minAmount The minimum amount of output token to receive
     */
    function swapWith3Pool(
        int128 inTokenIndex,
        int128 outTokenIndex,
        uint256 amount,
        uint256 minAmount
    ) external nonReentrant onlyLpRole {
        IERC20 inToken =
            IERC20(_STABLE_SWAP_3POOL.coins(uint256(inTokenIndex)));

        inToken.safeApprove(address(_STABLE_SWAP_3POOL), 0);
        inToken.safeApprove(address(_STABLE_SWAP_3POOL), amount);

        _STABLE_SWAP_3POOL.exchange(
            inTokenIndex,
            outTokenIndex,
            amount,
            minAmount
        );

        _lockOracleAdapter(lockPeriod);
    }

    function claim(string[] calldata names)
        external
        override
        nonReentrant
        onlyLpRole
    {
        uint256[] memory preClaimRewardsBalances = _getRewardsBalances();

        for (uint256 i = 0; i < names.length; i++) {
            string calldata name = names[i];
            IZap zap = _zaps.get(name);
            require(address(zap) != address(0), "INVALID_NAME");

            bool isErc20TokenRegistered =
                _checkErc20Registrations(zap.erc20Allocations());
            require(isErc20TokenRegistered, "MISSING_ERC20_ALLOCATIONS");

            address(zap).functionDelegateCall(
                abi.encodeWithSelector(IZap.claim.selector)
            );
        }

        uint256[] memory postClaimRewardsBalances = _getRewardsBalances();
        uint256[] memory rewardsFees =
            _calculateRewardsFees(
                preClaimRewardsBalances,
                postClaimRewardsBalances
            );
        _sendFeesToTreasurySafe(rewardsFees);

        _lockOracleAdapter(lockPeriod);
    }

    function registerRewardFee(address token, uint256 fee)
        external
        override
        onlyAdminRole
    {
        _registerRewardFee(token, fee);
    }

    function registerMultipleRewardFees(
        address[] calldata tokens,
        uint256[] calldata fees
    ) external override onlyAdminRole {
        require(tokens.length == fees.length, "INPUT_ARRAYS_MISMATCH");
        for (uint256 i = 0; i < tokens.length; i++) {
            _registerRewardFee(tokens[i], fees[i]);
        }
    }

    function removeRewardFee(address token) external override onlyAdminRole {
        _removeRewardFee(token);
    }

    function removeMultipleRewardFees(address[] calldata tokens)
        external
        override
        onlyAdminRole
    {
        for (uint256 i = 0; i < tokens.length; i++) {
            _removeRewardFee(tokens[i]);
        }
    }

    function emergencyExit(address token) external override onlyEmergencyRole {
        address emergencySafe = addressRegistry.emergencySafeAddress();
        IERC20 token_ = IERC20(token);
        uint256 balance = token_.balanceOf(address(this));
        token_.safeTransfer(emergencySafe, balance);

        emit EmergencyExit(emergencySafe, token_, balance);
    }

    function getLpTokenBalance(string calldata name)
        external
        view
        returns (uint256 value)
    {
        address zap = address(_zaps.get(name));
        require(zap != address(0), "INVALID_NAME");
        bytes memory data =
            zap.functionStaticCall(
                abi.encodeWithSelector(
                    IZap.getLpTokenBalance.selector,
                    address(this)
                )
            );
        // Convert bytes to uint256
        assembly {
            value := mload(add(data, 0x20))
        }
    }

    function zapNames() external view override returns (string[] memory) {
        return _zaps.names();
    }

    function swapNames() external view override returns (string[] memory) {
        return _swaps.names();
    }

    /**
     * @notice Lock oracle adapter for the configured period
     * @param lockPeriod_ The number of blocks to lock for
     */
    function _lockOracleAdapter(uint256 lockPeriod_) internal {
        ILockingOracle oracleAdapter =
            ILockingOracle(addressRegistry.oracleAdapterAddress());
        // solhint-disable no-empty-blocks
        try oracleAdapter.lockFor(lockPeriod_) {} catch Error(
            string memory reason
        ) {
            // Silence the revert in the case when Oracle Adapter is already
            // locked but with longer period.  In other cases, bubble
            // up the revert.
            require(
                keccak256(bytes(reason)) ==
                    keccak256(bytes("CANNOT_SHORTEN_LOCK")),
                reason
            );
        } catch (bytes memory) {
            revert("UNKNOWN_REASON");
        }
        // solhint-enable no-empty-blocks
    }

    function _setAddressRegistry(address addressRegistry_) internal {
        require(Address.isContract(addressRegistry_), "INVALID_ADDRESS");
        addressRegistry = IAddressRegistryV2(addressRegistry_);
        emit AddressRegistryChanged(addressRegistry_);
    }

    function _registerRewardFee(address token, uint256 fee) internal {
        require(Address.isContract(token), "INVALID_ADDRESS");
        require(fee != 0, "INVALID_REWARD_FEE");
        _rewardTokens.add(token);
        rewardFee[token] = fee;

        emit RewardFeeRegistered(token, fee);
    }

    function _removeRewardFee(address token) internal {
        _rewardTokens.remove(token);
        rewardFee[token] = 0;

        emit RewardFeeRemoved(token);
    }

    function _sendFeesToTreasurySafe(uint256[] memory rewardsFees) internal {
        require(
            _rewardTokens.length() == rewardsFees.length,
            "FEE_LENGTH_MISMATCH"
        );
        address treasurySafeAddress =
            addressRegistry.getAddress("treasurySafe");
        for (uint256 i = 0; i < _rewardTokens.length(); i++) {
            if (rewardsFees[i] > 0) {
                address tokenAddress = _rewardTokens.at(i);
                IERC20(tokenAddress).safeTransfer(
                    treasurySafeAddress,
                    rewardsFees[i]
                );
            }
        }
    }

    /**
     * @notice Check if multiple asset allocations are ALL registered
     * @param allocationNames An array of asset allocation names to check
     * @return `true` if every asset allocation is registered, otherwise `false`
     */
    function _checkAllocationRegistrations(string[] memory allocationNames)
        internal
        view
        returns (bool)
    {
        IAssetAllocationRegistry tvlManager =
            IAssetAllocationRegistry(addressRegistry.getAddress("tvlManager"));

        return tvlManager.isAssetAllocationRegistered(allocationNames);
    }

    /**
     * @notice Check if multiple ERC20 asset allocations are ALL registered
     * @param tokens An array of ERC20 tokens to check
     * @return `true` if every ERC20 is registered, otherwise `false`
     */
    function _checkErc20Registrations(IERC20[] memory tokens)
        internal
        view
        returns (bool)
    {
        IAssetAllocationRegistry tvlManager =
            IAssetAllocationRegistry(addressRegistry.getAddress("tvlManager"));
        IErc20Allocation erc20Allocation =
            IErc20Allocation(
                address(
                    tvlManager.getAssetAllocation(Erc20AllocationConstants.NAME)
                )
            );

        return erc20Allocation.isErc20TokenRegistered(tokens);
    }

    function _getRewardsBalances()
        internal
        view
        returns (uint256[] memory balances)
    {
        balances = new uint256[](_rewardTokens.length());
        for (uint256 i = 0; i < _rewardTokens.length(); i++) {
            address tokenAddress = _rewardTokens.at(i);
            balances[i] = IERC20(tokenAddress).balanceOf(address(this));
        }
    }

    function _calculateRewardsFees(
        uint256[] memory preClaimRewardsBalances,
        uint256[] memory postClaimRewardsBalances
    ) internal view returns (uint256[] memory rewardsFees) {
        require(
            preClaimRewardsBalances.length == postClaimRewardsBalances.length,
            "INPUT_ARRAYS_MISMATCH"
        );
        require(
            _rewardTokens.length() == preClaimRewardsBalances.length,
            "BALANCE_LENGTH_MISMATCH"
        );
        rewardsFees = new uint256[](_rewardTokens.length());
        for (uint256 i = 0; i < _rewardTokens.length(); i++) {
            uint256 balanceDelta =
                postClaimRewardsBalances[i].sub(preClaimRewardsBalances[i]);
            if (balanceDelta > 0) {
                address tokenAddress = _rewardTokens.at(i);
                uint256 fee = rewardFee[tokenAddress];
                rewardsFees[i] = balanceDelta.mul(fee).div(10000);
            }
        }
    }
}

// File: contracts/common/Imports.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import {IDetailedERC20} from "./IDetailedERC20.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {
    ReentrancyGuard
} from "@openzeppelin/contracts/utils/ReentrancyGuard.sol";

import {AccessControl} from "./AccessControl.sol";
import {INameIdentifier} from "./INameIdentifier.sol";
import {IAssetAllocation} from "./IAssetAllocation.sol";
import {IEmergencyExit} from "./IEmergencyExit.sol";

// File: contracts/libraries/Imports.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {Address} from "@openzeppelin/contracts/utils/Address.sol";
import {SafeMath} from "@openzeppelin/contracts/math/SafeMath.sol";
import {SignedSafeMath} from "@openzeppelin/contracts/math/SignedSafeMath.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import {EnumerableSet} from "@openzeppelin/contracts/utils/EnumerableSet.sol";

import {NamedAddressSet} from "./NamedAddressSet.sol";

// File: contracts/proxy/Imports.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {Initializable} from "./Initializable.sol";
import {
    OwnableUpgradeSafe
} from "@openzeppelin/contracts-ethereum-package/contracts/access/Ownable.sol";
import {
    ERC20UpgradeSafe
} from "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20.sol";
import {
    ReentrancyGuardUpgradeSafe
} from "@openzeppelin/contracts-ethereum-package/contracts/utils/ReentrancyGuard.sol";
import {
    PausableUpgradeSafe
} from "@openzeppelin/contracts-ethereum-package/contracts/utils/Pausable.sol";
import {AccessControlUpgradeSafe} from "./AccessControlUpgradeSafe.sol";

import {ProxyAdmin} from "@openzeppelin/contracts/proxy/ProxyAdmin.sol";
import {
    TransparentUpgradeableProxy
} from "@openzeppelin/contracts/proxy/TransparentUpgradeableProxy.sol";

/* Aliases don't persist so we can't rename them here, but you should
 * rename them at point of import with the "UpgradeSafe" prefix, e.g.
 * import {Address as AddressUpgradeSafe} etc.
 */
import {
    Address
} from "@openzeppelin/contracts-ethereum-package/contracts/utils/Address.sol";
import {
    SafeMath
} from "@openzeppelin/contracts-ethereum-package/contracts/math/SafeMath.sol";
import {
    SignedSafeMath
} from "@openzeppelin/contracts-ethereum-package/contracts/math/SignedSafeMath.sol";

// File: contracts/pool/Imports.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IReservePool} from "./IReservePool.sol";
import {IWithdrawFeePool} from "./IWithdrawFeePool.sol";
import {ILockingPool} from "./ILockingPool.sol";
import {IPoolToken} from "./IPoolToken.sol";
import {ILiquidityPoolV2} from "./ILiquidityPoolV2.sol";

// File: contracts/registry/Imports.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IAddressRegistryV2} from "./IAddressRegistryV2.sol";

// File: contracts/tvl/Imports.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IErc20Allocation} from "./IErc20Allocation.sol";
import {IChainlinkRegistry} from "./IChainlinkRegistry.sol";
import {IAssetAllocationRegistry} from "./IAssetAllocationRegistry.sol";
import {AssetAllocationBase} from "./AssetAllocationBase.sol";
import {ImmutableAssetAllocation} from "./ImmutableAssetAllocation.sol";
import {Erc20AllocationConstants} from "./Erc20Allocation.sol";

// File: contracts/lpaccount/Imports.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IZap} from "./IZap.sol";
import {ISwap} from "./ISwap.sol";
import {ILpAccount} from "./ILpAccount.sol";
import {ILpAccountV2} from "./ILpAccountV2.sol";
import {IZapRegistry} from "./IZapRegistry.sol";
import {ISwapRegistry} from "./ISwapRegistry.sol";
import {IStableSwap3Pool} from "./IStableSwap3Pool.sol";
import {IRewardFeeRegistry} from "./IRewardFeeRegistry.sol";

// File: contracts/oracle/Imports.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {AggregatorV3Interface, FluxAggregator} from "./FluxAggregator.sol";
import {IOracleAdapter} from "./IOracleAdapter.sol";
import {IOverrideOracle} from "./IOverrideOracle.sol";
import {ILockingOracle} from "./ILockingOracle.sol";

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

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

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

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

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

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

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

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "./IERC20.sol";
import "../../math/SafeMath.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 SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    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'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(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");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts/common/IDetailedERC20.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";

interface IDetailedERC20 is IERC20 {
    function name() external view returns (string memory);

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

    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../utils/Context.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 Ownable is Context {
    address private _owner;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

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

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

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

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

// File: @openzeppelin/contracts/utils/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

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

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

    uint256 private _status;

    constructor () internal {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

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

        _;

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

// File: contracts/common/AccessControl.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.6.11;

import {
    AccessControl as OZAccessControl
} from "@openzeppelin/contracts/access/AccessControl.sol";

/**
 * @notice Extends OpenZeppelin AccessControl contract with modifiers
 * @dev This contract and AccessControlUpgradeSafe are essentially duplicates.
 */
contract AccessControl is OZAccessControl {
    /** @notice access control roles **/
    bytes32 public constant CONTRACT_ROLE = keccak256("CONTRACT_ROLE");
    bytes32 public constant LP_ROLE = keccak256("LP_ROLE");
    bytes32 public constant ADMIN_ROLE = keccak256("ADMIN_ROLE");
    bytes32 public constant EMERGENCY_ROLE = keccak256("EMERGENCY_ROLE");

    modifier onlyLpRole() {
        require(hasRole(LP_ROLE, _msgSender()), "NOT_LP_ROLE");
        _;
    }

    modifier onlyContractRole() {
        require(hasRole(CONTRACT_ROLE, _msgSender()), "NOT_CONTRACT_ROLE");
        _;
    }

    modifier onlyAdminRole() {
        require(hasRole(ADMIN_ROLE, _msgSender()), "NOT_ADMIN_ROLE");
        _;
    }

    modifier onlyEmergencyRole() {
        require(hasRole(EMERGENCY_ROLE, _msgSender()), "NOT_EMERGENCY_ROLE");
        _;
    }

    modifier onlyLpOrContractRole() {
        require(
            hasRole(LP_ROLE, _msgSender()) ||
                hasRole(CONTRACT_ROLE, _msgSender()),
            "NOT_LP_OR_CONTRACT_ROLE"
        );
        _;
    }

    modifier onlyAdminOrContractRole() {
        require(
            hasRole(ADMIN_ROLE, _msgSender()) ||
                hasRole(CONTRACT_ROLE, _msgSender()),
            "NOT_ADMIN_OR_CONTRACT_ROLE"
        );
        _;
    }
}

// File: contracts/common/INameIdentifier.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

/**
 * @notice Used by the `NamedAddressSet` library to store sets of contracts
 */
interface INameIdentifier {
    /// @notice Should be implemented as a constant value
    // solhint-disable-next-line func-name-mixedcase
    function NAME() external view returns (string memory);
}

// File: contracts/common/IAssetAllocation.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {INameIdentifier} from "./INameIdentifier.sol";

/**
 * @notice For use with the `TvlManager` to track the value locked in a protocol
 */
interface IAssetAllocation is INameIdentifier {
    struct TokenData {
        address token;
        string symbol;
        uint8 decimals;
    }

    /**
     * @notice Get data for the underlying tokens stored in the protocol
     * @return The array of `TokenData`
     */
    function tokens() external view returns (TokenData[] memory);

    /**
     * @notice Get the number of different tokens stored in the protocol
     * @return The number of tokens
     */
    function numberOfTokens() external view returns (uint256);

    /**
     * @notice Get an account's balance for a token stored in the protocol
     * @dev The token index should be ordered the same as the `tokens()` array
     * @param account The account to get the balance for
     * @param tokenIndex The index of the token to get the balance for
     * @return The account's balance
     */
    function balanceOf(address account, uint8 tokenIndex)
        external
        view
        returns (uint256);

    /**
     * @notice Get the symbol of a token stored in the protocol
     * @dev The token index should be ordered the same as the `tokens()` array
     * @param tokenIndex The index of the token
     * @return The symbol of the token
     */
    function symbolOf(uint8 tokenIndex) external view returns (string memory);

    /**
     * @notice Get the decimals of a token stored in the protocol
     * @dev The token index should be ordered the same as the `tokens()` array
     * @param tokenIndex The index of the token
     * @return The decimals of the token
     */
    function decimalsOf(uint8 tokenIndex) external view returns (uint8);
}

// File: contracts/common/IEmergencyExit.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IERC20} from "./Imports.sol";

/**
 * @notice Used for contracts that need an emergency escape hatch
 * @notice Should only be used in an emergency to keep funds safu
 */
interface IEmergencyExit {
    /**
     * @param emergencySafe The address the tokens were escaped to
     * @param token The token escaped
     * @param balance The amount of tokens escaped
     */
    event EmergencyExit(address emergencySafe, IERC20 token, uint256 balance);

    /**
     * @notice Transfer all tokens to the emergency Safe
     * @dev Should only be callable by the emergency Safe
     * @dev Should only transfer tokens to the emergency Safe
     * @param token The token to transfer
     */
    function emergencyExit(address token) external;
}

// File: @openzeppelin/contracts/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @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) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        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) {
        // 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) {
        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) {
        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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @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) {
        require(b <= a, "SafeMath: subtraction overflow");
        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) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    /**
     * @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. 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) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        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) {
        require(b > 0, "SafeMath: modulo by zero");
        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) {
        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.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * 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) {
        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) {
        require(b > 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.2 <0.8.0;

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

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

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

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

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

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

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/*
 * @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 GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @openzeppelin/contracts/access/AccessControl.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../utils/EnumerableSet.sol";
import "../utils/Address.sol";
import "../utils/Context.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context {
    using EnumerableSet for EnumerableSet.AddressSet;
    using Address for address;

    struct RoleData {
        EnumerableSet.AddressSet members;
        bytes32 adminRole;
    }

    mapping (bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @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 {_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) public view returns (bool) {
        return _roles[role].members.contains(account);
    }

    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) public view returns (uint256) {
        return _roles[role].members.length();
    }

    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) public view returns (address) {
        return _roles[role].members.at(index);
    }

    /**
     * @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 returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual {
        require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to grant");

        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual {
        require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to revoke");

        _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 granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

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

    function _grantRole(bytes32 role, address account) private {
        if (_roles[role].members.add(account)) {
            emit RoleGranted(role, account, _msgSender());
        }
    }

    function _revokeRole(bytes32 role, address account) private {
        if (_roles[role].members.remove(account)) {
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}

// File: @openzeppelin/contracts/utils/EnumerableSet.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

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

    struct Set {
        // Storage of set values
        bytes32[] _values;

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

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

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

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

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

            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.

            bytes32 lastvalue = set._values[lastIndex];

            // Move the last value to the index where the value to delete is
            set._values[toDeleteIndex] = lastvalue;
            // Update the index for the moved value
            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based

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

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

            return true;
        } else {
            return false;
        }
    }

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

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

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

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

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

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

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

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

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

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

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

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

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

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

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


    // UintSet

    struct UintSet {
        Set _inner;
    }

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

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

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

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

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

// File: @openzeppelin/contracts/math/SignedSafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @title SignedSafeMath
 * @dev Signed math operations with safety checks that revert on error.
 */
library SignedSafeMath {
    int256 constant private _INT256_MIN = -2**255;

    /**
     * @dev Returns the multiplication of two signed integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(int256 a, int256 b) internal pure returns (int256) {
        // 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 0;
        }

        require(!(a == -1 && b == _INT256_MIN), "SignedSafeMath: multiplication overflow");

        int256 c = a * b;
        require(c / a == b, "SignedSafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two signed integers. Reverts 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(int256 a, int256 b) internal pure returns (int256) {
        require(b != 0, "SignedSafeMath: division by zero");
        require(!(b == -1 && a == _INT256_MIN), "SignedSafeMath: division overflow");

        int256 c = a / b;

        return c;
    }

    /**
     * @dev Returns the subtraction of two signed integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a - b;
        require((b >= 0 && c <= a) || (b < 0 && c > a), "SignedSafeMath: subtraction overflow");

        return c;
    }

    /**
     * @dev Returns the addition of two signed integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a + b;
        require((b >= 0 && c >= a) || (b < 0 && c < a), "SignedSafeMath: addition overflow");

        return c;
    }
}

// File: contracts/libraries/NamedAddressSet.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {Address} from "@openzeppelin/contracts/utils/Address.sol";
import {EnumerableSet} from "@openzeppelin/contracts/utils/EnumerableSet.sol";

import {IAssetAllocation, INameIdentifier} from "contracts/common/Imports.sol";
import {IZap, ISwap} from "contracts/lpaccount/Imports.sol";

/**
 * @notice Stores a set of addresses that can be looked up by name
 * @notice Addresses can be added or removed dynamically
 * @notice Useful for keeping track of unique deployed contracts
 * @dev Each address must be a contract with a `NAME` constant for lookup
 */
// solhint-disable ordering
library NamedAddressSet {
    using EnumerableSet for EnumerableSet.AddressSet;

    struct Set {
        EnumerableSet.AddressSet _namedAddresses;
        mapping(string => INameIdentifier) _nameLookup;
    }

    struct AssetAllocationSet {
        Set _inner;
    }

    struct ZapSet {
        Set _inner;
    }

    struct SwapSet {
        Set _inner;
    }

    function _add(Set storage set, INameIdentifier namedAddress) private {
        require(Address.isContract(address(namedAddress)), "INVALID_ADDRESS");
        require(
            !set._namedAddresses.contains(address(namedAddress)),
            "DUPLICATE_ADDRESS"
        );

        string memory name = namedAddress.NAME();
        require(bytes(name).length != 0, "INVALID_NAME");
        require(address(set._nameLookup[name]) == address(0), "DUPLICATE_NAME");

        set._namedAddresses.add(address(namedAddress));
        set._nameLookup[name] = namedAddress;
    }

    function _remove(Set storage set, string memory name) private {
        address namedAddress = address(set._nameLookup[name]);
        require(namedAddress != address(0), "INVALID_NAME");

        set._namedAddresses.remove(namedAddress);
        delete set._nameLookup[name];
    }

    function _contains(Set storage set, INameIdentifier namedAddress)
        private
        view
        returns (bool)
    {
        return set._namedAddresses.contains(address(namedAddress));
    }

    function _length(Set storage set) private view returns (uint256) {
        return set._namedAddresses.length();
    }

    function _at(Set storage set, uint256 index)
        private
        view
        returns (INameIdentifier)
    {
        return INameIdentifier(set._namedAddresses.at(index));
    }

    function _get(Set storage set, string memory name)
        private
        view
        returns (INameIdentifier)
    {
        return set._nameLookup[name];
    }

    function _names(Set storage set) private view returns (string[] memory) {
        uint256 length_ = set._namedAddresses.length();
        string[] memory names_ = new string[](length_);

        for (uint256 i = 0; i < length_; i++) {
            INameIdentifier namedAddress =
                INameIdentifier(set._namedAddresses.at(i));
            names_[i] = namedAddress.NAME();
        }

        return names_;
    }

    function add(
        AssetAllocationSet storage set,
        IAssetAllocation assetAllocation
    ) internal {
        _add(set._inner, assetAllocation);
    }

    function remove(AssetAllocationSet storage set, string memory name)
        internal
    {
        _remove(set._inner, name);
    }

    function contains(
        AssetAllocationSet storage set,
        IAssetAllocation assetAllocation
    ) internal view returns (bool) {
        return _contains(set._inner, assetAllocation);
    }

    function length(AssetAllocationSet storage set)
        internal
        view
        returns (uint256)
    {
        return _length(set._inner);
    }

    function at(AssetAllocationSet storage set, uint256 index)
        internal
        view
        returns (IAssetAllocation)
    {
        return IAssetAllocation(address(_at(set._inner, index)));
    }

    function get(AssetAllocationSet storage set, string memory name)
        internal
        view
        returns (IAssetAllocation)
    {
        return IAssetAllocation(address(_get(set._inner, name)));
    }

    function names(AssetAllocationSet storage set)
        internal
        view
        returns (string[] memory)
    {
        return _names(set._inner);
    }

    function add(ZapSet storage set, IZap zap) internal {
        _add(set._inner, zap);
    }

    function remove(ZapSet storage set, string memory name) internal {
        _remove(set._inner, name);
    }

    function contains(ZapSet storage set, IZap zap)
        internal
        view
        returns (bool)
    {
        return _contains(set._inner, zap);
    }

    function length(ZapSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    function at(ZapSet storage set, uint256 index)
        internal
        view
        returns (IZap)
    {
        return IZap(address(_at(set._inner, index)));
    }

    function get(ZapSet storage set, string memory name)
        internal
        view
        returns (IZap)
    {
        return IZap(address(_get(set._inner, name)));
    }

    function names(ZapSet storage set) internal view returns (string[] memory) {
        return _names(set._inner);
    }

    function add(SwapSet storage set, ISwap swap) internal {
        _add(set._inner, swap);
    }

    function remove(SwapSet storage set, string memory name) internal {
        _remove(set._inner, name);
    }

    function contains(SwapSet storage set, ISwap swap)
        internal
        view
        returns (bool)
    {
        return _contains(set._inner, swap);
    }

    function length(SwapSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    function at(SwapSet storage set, uint256 index)
        internal
        view
        returns (ISwap)
    {
        return ISwap(address(_at(set._inner, index)));
    }

    function get(SwapSet storage set, string memory name)
        internal
        view
        returns (ISwap)
    {
        return ISwap(address(_get(set._inner, name)));
    }

    function names(SwapSet storage set)
        internal
        view
        returns (string[] memory)
    {
        return _names(set._inner);
    }
}
// solhint-enable ordering

// File: contracts/lpaccount/IZap.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {
    IAssetAllocation,
    INameIdentifier,
    IERC20
} from "contracts/common/Imports.sol";

/**
 * @notice Used to define how an LP Account farms an external protocol
 */
interface IZap is INameIdentifier {
    /**
     * @notice Deploy liquidity to a protocol (i.e. enter a farm)
     * @dev Implementation should add liquidity and stake LP tokens
     * @param amounts Amount of each token to deploy
     */
    function deployLiquidity(uint256[] calldata amounts) external;

    /**
     * @notice Unwind liquidity from a protocol (i.e exit a farm)
     * @dev Implementation should unstake LP tokens and remove liquidity
     * @dev If there is only one token to unwind, `index` should be 0
     * @param amount Amount of liquidity to unwind
     * @param index Which token should be unwound
     */
    function unwindLiquidity(uint256 amount, uint8 index) external;

    /**
     * @notice Claim accrued rewards from the protocol (i.e. harvest yield)
     */
    function claim() external;

    /**
     * @notice Retrieves the LP token balance
     */
    function getLpTokenBalance(address account) external view returns (uint256);

    /**
     * @notice Order of tokens for deploy `amounts` and unwind `index`
     * @dev Implementation should use human readable symbols
     * @dev Order should be the same for deploy and unwind
     * @return The array of symbols in order
     */
    function sortedSymbols() external view returns (string[] memory);

    /**
     * @notice Asset allocations to include in TVL
     * @dev Requires all allocations that track value deployed to the protocol
     * @return An array of the asset allocation names
     */
    function assetAllocations() external view returns (string[] memory);

    /**
     * @notice ERC20 asset allocations to include in TVL
     * @dev Should return addresses for all tokens that get deployed or unwound
     * @return The array of ERC20 token addresses
     */
    function erc20Allocations() external view returns (IERC20[] memory);
}

// File: contracts/lpaccount/ISwap.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {
    IAssetAllocation,
    INameIdentifier,
    IERC20
} from "contracts/common/Imports.sol";

/**
 * @notice Used to define a token swap that can be performed by an LP Account
 */
interface ISwap is INameIdentifier {
    /**
     * @dev Implementation should perform a token swap
     * @param amount The amount of the input token to swap
     * @param minAmount The minimum amount of the output token to accept
     */
    function swap(uint256 amount, uint256 minAmount) external;

    /**
     * @notice ERC20 asset allocations to include in TVL
     * @dev Should return addresses for all tokens going in and out of the swap
     * @return The array of ERC20 token addresses
     */
    function erc20Allocations() external view returns (IERC20[] memory);
}

// File: contracts/lpaccount/ILpAccount.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

/**
 * @notice For contracts that provide liquidity to external protocols
 */
interface ILpAccount {
    /**
     * @notice Deploy liquidity with a registered `IZap`
     * @dev The order of token amounts should match `IZap.sortedSymbols`
     * @param name The name of the `IZap`
     * @param amounts The token amounts to deploy
     */
    function deployStrategy(string calldata name, uint256[] calldata amounts)
        external;

    /**
     * @notice Unwind liquidity with a registered `IZap`
     * @dev The index should match the order of `IZap.sortedSymbols`
     * @param name The name of the `IZap`
     * @param amount The amount of the token to unwind
     * @param index The index of the token to unwind into
     */
    function unwindStrategy(
        string calldata name,
        uint256 amount,
        uint8 index
    ) external;

    /**
     * @notice Return liquidity to a pool
     * @notice Typically used to refill a liquidity pool's reserve
     * @dev This should only be callable by the `MetaPoolToken`
     * @param pool The `IReservePool` to transfer to
     * @param amount The amount of the pool's underlyer token to transer
     */
    function transferToPool(address pool, uint256 amount) external;

    /**
     * @notice Swap tokens with a registered `ISwap`
     * @notice Used to compound reward tokens
     * @notice Used to rebalance underlyer tokens
     * @param name The name of the `IZap`
     * @param amount The amount of tokens to swap
     * @param minAmount The minimum amount of tokens to receive from the swap
     */
    function swap(
        string calldata name,
        uint256 amount,
        uint256 minAmount
    ) external;

    /**
     * @notice Claim reward tokens with a registered `IZap`
     * @param name The name of the `IZap`
     */
    function claim(string calldata name) external;
}

// File: contracts/lpaccount/ILpAccountV2.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

/**
 * @notice For contracts that provide liquidity to external protocols
 */
interface ILpAccountV2 {
    /**
     * @notice Deploy liquidity with a registered `IZap`
     * @dev The order of token amounts should match `IZap.sortedSymbols`
     * @param name The name of the `IZap`
     * @param amounts The token amounts to deploy
     */
    function deployStrategy(string calldata name, uint256[] calldata amounts)
        external;

    /**
     * @notice Unwind liquidity with a registered `IZap`
     * @dev The index should match the order of `IZap.sortedSymbols`
     * @param name The name of the `IZap`
     * @param amount The amount of the token to unwind
     * @param index The index of the token to unwind into
     */
    function unwindStrategy(
        string calldata name,
        uint256 amount,
        uint8 index
    ) external;

    /**
     * @notice Return liquidity to a pool
     * @notice Typically used to refill a liquidity pool's reserve
     * @dev This should only be callable by the `MetaPoolToken`
     * @param pool The `IReservePool` to transfer to
     * @param amount The amount of the pool's underlyer token to transer
     */
    function transferToPool(address pool, uint256 amount) external;

    /**
     * @notice Swap tokens with a registered `ISwap`
     * @notice Used to compound reward tokens
     * @notice Used to rebalance underlyer tokens
     * @param name The name of the `IZap`
     * @param amount The amount of tokens to swap
     * @param minAmount The minimum amount of tokens to receive from the swap
     */
    function swap(
        string calldata name,
        uint256 amount,
        uint256 minAmount
    ) external;

    /**
     * @notice Claim reward tokens with registered `IZap`s
     * @param names The names of the `IZap`s
     */
    function claim(string[] calldata names) external;
}

// File: contracts/lpaccount/IZapRegistry.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {IZap} from "./IZap.sol";

/**
 * @notice For managing a collection of `IZap` contracts
 */
interface IZapRegistry {
    /** @notice Log when a new `IZap` is registered */
    event ZapRegistered(IZap zap);

    /** @notice Log when an `IZap` is removed */
    event ZapRemoved(string name);

    /**
     * @notice Add a new `IZap` to the registry
     * @dev Should not allow duplicate swaps
     * @param zap The new `IZap`
     */
    function registerZap(IZap zap) external;

    /**
     * @notice Remove an `IZap` from the registry
     * @param name The name of the `IZap` (see `INameIdentifier`)
     */
    function removeZap(string calldata name) external;

    /**
     * @notice Get the names of all registered `IZap`
     * @return An array of `IZap` names
     */
    function zapNames() external view returns (string[] memory);
}

// File: contracts/lpaccount/ISwapRegistry.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {ISwap} from "./ISwap.sol";

/**
 * @notice For managing a collection of `ISwap` contracts
 */
interface ISwapRegistry {
    /** @notice Log when a new `ISwap` is registered */
    event SwapRegistered(ISwap swap);

    /** @notice Log when an `ISwap` is removed */
    event SwapRemoved(string name);

    /**
     * @notice Add a new `ISwap` to the registry
     * @dev Should not allow duplicate swaps
     * @param swap The new `ISwap`
     */
    function registerSwap(ISwap swap) external;

    /**
     * @notice Remove an `ISwap` from the registry
     * @param name The name of the `ISwap` (see `INameIdentifier`)
     */
    function removeSwap(string calldata name) external;

    /**
     * @notice Get the names of all registered `ISwap`
     * @return An array of `ISwap` names
     */
    function swapNames() external view returns (string[] memory);
}

// File: contracts/lpaccount/IStableSwap3Pool.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

/**
 * @notice the stablecoin pool contract
 */
interface IStableSwap3Pool {
    function exchange(
        int128 i,
        int128 j,
        uint256 dx,
        uint256 min_dy // solhint-disable-line func-param-name-mixedcase
    ) external;

    function coins(uint256 coin) external view returns (address);

    // solhint-disable-next-line func-name-mixedcase
    function get_dy(
        int128 i,
        int128 j,
        uint256 dx
    ) external view returns (uint256);
}

// File: contracts/lpaccount/IRewardFeeRegistry.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

/**
 * @notice For managing a collection of `IZap` contracts
 */
interface IRewardFeeRegistry {
    /** @notice Log when a reward fee is registered */
    event RewardFeeRegistered(address token, uint256 fee);

    /** @notice Log when reward fee is removed */
    event RewardFeeRemoved(address token);

    /**
     * @notice register a reward token and its fee
     * @param token address of reward token
     * @param fee percentage to charge fee in basis points
     */
    function registerRewardFee(address token, uint256 fee) external;

    /**
     * @notice register multiple reward tokens with fees
     * @param tokens addresss of reward tokens
     * @param fees percentage to charge fee in basis points
     */
    function registerMultipleRewardFees(
        address[] calldata tokens,
        uint256[] calldata fees
    ) external;

    /**
     * @notice deregister reward token
     * @param token address of reward token to deregister
     */
    function removeRewardFee(address token) external;

    /**
     * @notice deregister multiple reward tokens
     * @param tokens addresses of reward tokens to deregister
     */
    function removeMultipleRewardFees(address[] calldata tokens) external;
}

// File: contracts/proxy/Initializable.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {
    Initializable as OZInitializable
} from "@openzeppelin/contracts-ethereum-package/contracts/Initializable.sol";

contract Initializable is OZInitializable {
    /**
     * @dev Throws if called by any account other than the proxy admin.
     */
    modifier onlyProxyAdmin() {
        require(msg.sender == proxyAdmin(), "PROXY_ADMIN_ONLY");
        _;
    }

    /**
     * @dev Returns the proxy admin address using the slot specified in EIP-1967:
     *
     * 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103
     *  = bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1)
     */
    function proxyAdmin() public view returns (address adm) {
        bytes32 slot =
            0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            adm := sload(slot)
        }
    }
}

// File: @openzeppelin/contracts-ethereum-package/contracts/access/Ownable.sol



pragma solidity ^0.6.0;

import "../GSN/Context.sol";
import "../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.
 */
contract OwnableUpgradeSafe is Initializable, ContextUpgradeSafe {
    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 initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal initializer {


        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);

    }


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

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

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

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

    uint256[49] private __gap;
}

// File: @openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20.sol



pragma solidity ^0.6.0;

import "../../GSN/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
import "../../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 {ERC20MinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of 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 ERC20UpgradeSafe is Initializable, ContextUpgradeSafe, IERC20 {
    using SafeMath for uint256;
    using Address for address;

    mapping (address => uint256) private _balances;

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

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */

    function __ERC20_init(string memory name, string memory symbol) internal initializer {
        __Context_init_unchained();
        __ERC20_init_unchained(name, symbol);
    }

    function __ERC20_init_unchained(string memory name, string memory symbol) internal initializer {


        _name = name;
        _symbol = symbol;
        _decimals = 18;

    }


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

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

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * 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 returns (uint8) {
        return _decimals;
    }

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

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

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

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

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

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

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(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) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

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

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements
     *
     * - `to` 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 = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(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);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
     *
     * This is 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 Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    /**
     * @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 to 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 { }

    uint256[44] private __gap;
}

// File: @openzeppelin/contracts-ethereum-package/contracts/utils/ReentrancyGuard.sol



pragma solidity ^0.6.0;
import "../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].
 */
contract ReentrancyGuardUpgradeSafe is Initializable {
    bool private _notEntered;


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

    function __ReentrancyGuard_init_unchained() internal initializer {


        // Storing an initial 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 percetange 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.
        _notEntered = true;

    }


    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_notEntered, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _notEntered = false;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _notEntered = true;
    }

    uint256[49] private __gap;
}

// File: @openzeppelin/contracts-ethereum-package/contracts/utils/Pausable.sol



pragma solidity ^0.6.0;

import "../GSN/Context.sol";
import "../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.
 */
contract PausableUpgradeSafe is Initializable, ContextUpgradeSafe {
    /**
     * @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 initializer {
        __Context_init_unchained();
        __Pausable_init_unchained();
    }

    function __Pausable_init_unchained() internal initializer {


        _paused = false;

    }


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

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     */
    modifier whenNotPaused() {
        require(!_paused, "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     */
    modifier whenPaused() {
        require(_paused, "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }

    uint256[49] private __gap;
}

// File: contracts/proxy/AccessControlUpgradeSafe.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.6.11;

import {
    AccessControlUpgradeSafe as OZAccessControl
} from "@openzeppelin/contracts-ethereum-package/contracts/access/AccessControl.sol";

/**
 * @notice Extends OpenZeppelin upgradeable AccessControl contract with modifiers
 * @dev This contract and AccessControl are essentially duplicates.
 */
contract AccessControlUpgradeSafe is OZAccessControl {
    /** @notice access control roles **/
    bytes32 public constant CONTRACT_ROLE = keccak256("CONTRACT_ROLE");
    bytes32 public constant LP_ROLE = keccak256("LP_ROLE");
    bytes32 public constant ADMIN_ROLE = keccak256("ADMIN_ROLE");
    bytes32 public constant EMERGENCY_ROLE = keccak256("EMERGENCY_ROLE");

    modifier onlyLpRole() {
        require(hasRole(LP_ROLE, _msgSender()), "NOT_LP_ROLE");
        _;
    }

    modifier onlyContractRole() {
        require(hasRole(CONTRACT_ROLE, _msgSender()), "NOT_CONTRACT_ROLE");
        _;
    }

    modifier onlyAdminRole() {
        require(hasRole(ADMIN_ROLE, _msgSender()), "NOT_ADMIN_ROLE");
        _;
    }

    modifier onlyEmergencyRole() {
        require(hasRole(EMERGENCY_ROLE, _msgSender()), "NOT_EMERGENCY_ROLE");
        _;
    }

    modifier onlyLpOrContractRole() {
        require(
            hasRole(LP_ROLE, _msgSender()) ||
                hasRole(CONTRACT_ROLE, _msgSender()),
            "NOT_LP_OR_CONTRACT_ROLE"
        );
        _;
    }

    modifier onlyAdminOrContractRole() {
        require(
            hasRole(ADMIN_ROLE, _msgSender()) ||
                hasRole(CONTRACT_ROLE, _msgSender()),
            "NOT_ADMIN_OR_CONTRACT_ROLE"
        );
        _;
    }
}

// File: @openzeppelin/contracts/proxy/ProxyAdmin.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../access/Ownable.sol";
import "./TransparentUpgradeableProxy.sol";

/**
 * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
 * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
 */
contract ProxyAdmin is Ownable {

    /**
     * @dev Returns the current implementation of `proxy`.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function getProxyImplementation(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
        // We need to manually run the static call since the getter cannot be flagged as view
        // bytes4(keccak256("implementation()")) == 0x5c60da1b
        (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
        require(success);
        return abi.decode(returndata, (address));
    }

    /**
     * @dev Returns the current admin of `proxy`.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function getProxyAdmin(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
        // We need to manually run the static call since the getter cannot be flagged as view
        // bytes4(keccak256("admin()")) == 0xf851a440
        (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
        require(success);
        return abi.decode(returndata, (address));
    }

    /**
     * @dev Changes the admin of `proxy` to `newAdmin`.
     *
     * Requirements:
     *
     * - This contract must be the current admin of `proxy`.
     */
    function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
        proxy.changeAdmin(newAdmin);
    }

    /**
     * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function upgrade(TransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
        proxy.upgradeTo(implementation);
    }

    /**
     * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
     * {TransparentUpgradeableProxy-upgradeToAndCall}.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function upgradeAndCall(TransparentUpgradeableProxy proxy, address implementation, bytes memory data) public payable virtual onlyOwner {
        proxy.upgradeToAndCall{value: msg.value}(implementation, data);
    }
}

// File: @openzeppelin/contracts/proxy/TransparentUpgradeableProxy.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "./UpgradeableProxy.sol";

/**
 * @dev This contract implements a proxy that is upgradeable by an admin.
 *
 * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
 * clashing], which can potentially be used in an attack, this contract uses the
 * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
 * things that go hand in hand:
 *
 * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
 * that call matches one of the admin functions exposed by the proxy itself.
 * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
 * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
 * "admin cannot fallback to proxy target".
 *
 * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
 * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
 * to sudden errors when trying to call a function from the proxy implementation.
 *
 * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
 * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
 */
contract TransparentUpgradeableProxy is UpgradeableProxy {
    /**
     * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
     * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}.
     */
    constructor(address _logic, address admin_, bytes memory _data) public payable UpgradeableProxy(_logic, _data) {
        assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
        _setAdmin(admin_);
    }

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

    /**
     * @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 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
     */
    modifier ifAdmin() {
        if (msg.sender == _admin()) {
            _;
        } else {
            _fallback();
        }
    }

    /**
     * @dev Returns the current admin.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
     */
    function admin() external ifAdmin returns (address admin_) {
        admin_ = _admin();
    }

    /**
     * @dev Returns the current implementation.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
     */
    function implementation() external ifAdmin returns (address implementation_) {
        implementation_ = _implementation();
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
     */
    function changeAdmin(address newAdmin) external virtual ifAdmin {
        require(newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address");
        emit AdminChanged(_admin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev Upgrade the implementation of the proxy.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
     */
    function upgradeTo(address newImplementation) external virtual ifAdmin {
        _upgradeTo(newImplementation);
    }

    /**
     * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
     * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
     * proxied contract.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
     */
    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable virtual ifAdmin {
        _upgradeTo(newImplementation);
        Address.functionDelegateCall(newImplementation, data);
    }

    /**
     * @dev Returns the current admin.
     */
    function _admin() internal view virtual returns (address adm) {
        bytes32 slot = _ADMIN_SLOT;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            adm := sload(slot)
        }
    }

    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        bytes32 slot = _ADMIN_SLOT;

        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(slot, newAdmin)
        }
    }

    /**
     * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
     */
    function _beforeFallback() internal virtual override {
        require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
        super._beforeFallback();
    }
}

// File: @openzeppelin/contracts-ethereum-package/contracts/utils/Address.sol



pragma solidity ^0.6.2;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

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

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}

// File: @openzeppelin/contracts-ethereum-package/contracts/math/SafeMath.sol



pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @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 sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @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) {
        // 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 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts 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 mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts-ethereum-package/contracts/math/SignedSafeMath.sol



pragma solidity ^0.6.0;

/**
 * @title SignedSafeMath
 * @dev Signed math operations with safety checks that revert on error.
 */
library SignedSafeMath {
    int256 constant private _INT256_MIN = -2**255;

    /**
     * @dev Multiplies two signed integers, reverts on overflow.
     */
    function mul(int256 a, int256 b) internal pure returns (int256) {
        // 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 0;
        }

        require(!(a == -1 && b == _INT256_MIN), "SignedSafeMath: multiplication overflow");

        int256 c = a * b;
        require(c / a == b, "SignedSafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Integer division of two signed integers truncating the quotient, reverts on division by zero.
     */
    function div(int256 a, int256 b) internal pure returns (int256) {
        require(b != 0, "SignedSafeMath: division by zero");
        require(!(b == -1 && a == _INT256_MIN), "SignedSafeMath: division overflow");

        int256 c = a / b;

        return c;
    }

    /**
     * @dev Subtracts two signed integers, reverts on overflow.
     */
    function sub(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a - b;
        require((b >= 0 && c <= a) || (b < 0 && c > a), "SignedSafeMath: subtraction overflow");

        return c;
    }

    /**
     * @dev Adds two signed integers, reverts on overflow.
     */
    function add(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a + b;
        require((b >= 0 && c >= a) || (b < 0 && c < a), "SignedSafeMath: addition overflow");

        return c;
    }
}

// File: @openzeppelin/contracts-ethereum-package/contracts/Initializable.sol



pragma solidity >=0.4.24 <0.7.0;


/**
 * @title Initializable
 *
 * @dev Helper contract to support initializer functions. To use it, replace
 * the constructor with a function that has the `initializer` modifier.
 * WARNING: Unlike constructors, initializer functions must be manually
 * invoked. This applies both to deploying an Initializable contract, as well
 * as extending an Initializable contract via inheritance.
 * WARNING: When used with inheritance, manual care must be taken to not invoke
 * a parent initializer twice, or ensure that all initializers are idempotent,
 * because this is not dealt with automatically as with constructors.
 */
contract Initializable {

  /**
   * @dev Indicates that the contract has been initialized.
   */
  bool private initialized;

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

  /**
   * @dev Modifier to use in the initializer function of a contract.
   */
  modifier initializer() {
    require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");

    bool isTopLevelCall = !initializing;
    if (isTopLevelCall) {
      initializing = true;
      initialized = true;
    }

    _;

    if (isTopLevelCall) {
      initializing = false;
    }
  }

  /// @dev Returns true if and only if the function is running in the constructor
  function isConstructor() private view returns (bool) {
    // extcodesize checks the size of the code stored in an address, and
    // address returns the current address. Since the code is still not
    // deployed when running a constructor, any checks on its code size will
    // yield zero, making it an effective way to detect if a contract is
    // under construction or not.
    address self = address(this);
    uint256 cs;
    assembly { cs := extcodesize(self) }
    return cs == 0;
  }

  // Reserved storage space to allow for layout changes in the future.
  uint256[50] private ______gap;
}

// File: @openzeppelin/contracts-ethereum-package/contracts/GSN/Context.sol



pragma solidity ^0.6.0;
import "../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 GSN 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.
 */
contract ContextUpgradeSafe is Initializable {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.

    function __Context_init() internal initializer {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal initializer {


    }


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

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }

    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-ethereum-package/contracts/token/ERC20/IERC20.sol



pragma solidity ^0.6.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

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

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

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

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

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

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

// File: @openzeppelin/contracts-ethereum-package/contracts/access/AccessControl.sol



pragma solidity ^0.6.0;

import "../utils/EnumerableSet.sol";
import "../utils/Address.sol";
import "../GSN/Context.sol";
import "../Initializable.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, _msgSender()));
 *     ...
 * }
 * ```
 *
 * 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}.
 */
abstract contract AccessControlUpgradeSafe is Initializable, ContextUpgradeSafe {
    function __AccessControl_init() internal initializer {
        __Context_init_unchained();
        __AccessControl_init_unchained();
    }

    function __AccessControl_init_unchained() internal initializer {


    }

    using EnumerableSet for EnumerableSet.AddressSet;
    using Address for address;

    struct RoleData {
        EnumerableSet.AddressSet members;
        bytes32 adminRole;
    }

    mapping (bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {_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) public view returns (bool) {
        return _roles[role].members.contains(account);
    }

    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) public view returns (uint256) {
        return _roles[role].members.length();
    }

    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) public view returns (address) {
        return _roles[role].members.at(index);
    }

    /**
     * @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 returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual {
        require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to grant");

        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual {
        require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to revoke");

        _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 granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

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

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

    function _grantRole(bytes32 role, address account) private {
        if (_roles[role].members.add(account)) {
            emit RoleGranted(role, account, _msgSender());
        }
    }

    function _revokeRole(bytes32 role, address account) private {
        if (_roles[role].members.remove(account)) {
            emit RoleRevoked(role, account, _msgSender());
        }
    }

    uint256[49] private __gap;
}

// File: @openzeppelin/contracts-ethereum-package/contracts/utils/EnumerableSet.sol



pragma solidity ^0.6.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.0.0, only sets of type `address` (`AddressSet`) and `uint256`
 * (`UintSet`) are supported.
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;

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

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

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

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

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

            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.

            bytes32 lastvalue = set._values[lastIndex];

            // Move the last value to the index where the value to delete is
            set._values[toDeleteIndex] = lastvalue;
            // Update the index for the moved value
            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based

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

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

            return true;
        } else {
            return false;
        }
    }

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

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

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

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

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

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

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

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

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


    // UintSet

    struct UintSet {
        Set _inner;
    }

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

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

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

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

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

// File: @openzeppelin/contracts/proxy/UpgradeableProxy.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "./Proxy.sol";
import "../utils/Address.sol";

/**
 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
 * implementation address that can be changed. This address is stored in storage in the location specified by
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
 * implementation behind the proxy.
 *
 * Upgradeability is only provided internally through {_upgradeTo}. For an externally upgradeable proxy see
 * {TransparentUpgradeableProxy}.
 */
contract UpgradeableProxy is Proxy {
    /**
     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
     *
     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
     */
    constructor(address _logic, bytes memory _data) public payable {
        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
        _setImplementation(_logic);
        if(_data.length > 0) {
            Address.functionDelegateCall(_logic, _data);
        }
    }

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

    /**
     * @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 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Returns the current implementation address.
     */
    function _implementation() internal view virtual override returns (address impl) {
        bytes32 slot = _IMPLEMENTATION_SLOT;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            impl := sload(slot)
        }
    }

    /**
     * @dev Upgrades the proxy to a new implementation.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal virtual {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract");

        bytes32 slot = _IMPLEMENTATION_SLOT;

        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(slot, newImplementation)
        }
    }
}

// File: @openzeppelin/contracts/proxy/Proxy.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())

            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)

            // Copy the returned data.
            returndatacopy(0, 0, returndatasize())

            switch result
            // delegatecall returns 0 on error.
            case 0 { revert(0, returndatasize()) }
            default { return(0, returndatasize()) }
        }
    }

    /**
     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);

    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback () external payable virtual {
        _fallback();
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive () external payable virtual {
        _fallback();
    }

    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overriden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {
    }
}

// File: contracts/pool/IReservePool.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {ILiquidityPoolV2} from "./ILiquidityPoolV2.sol";

/**
 * @notice For pools that keep a separate reserve of tokens
 */
interface IReservePool is ILiquidityPoolV2 {
    /**
     * @notice Log when the percent held in reserve is changed
     * @param reservePercentage The new percent held in reserve
     */
    event ReservePercentageChanged(uint256 reservePercentage);

    /**
     * @notice Set a new percent of tokens to hold in reserve
     * @param reservePercentage_ The new percent
     */
    function setReservePercentage(uint256 reservePercentage_) external;

    /**
     * @notice Transfer an amount of tokens to the LP Account
     * @dev This should only be callable by the `MetaPoolToken`
     * @param amount The amount of tokens
     */
    function transferToLpAccount(uint256 amount) external;

    /**
     * @notice Get the amount of tokens missing from the reserve
     * @dev A negative amount indicates extra tokens not needed for the reserve
     * @return The amount of missing tokens
     */
    function getReserveTopUpValue() external view returns (int256);

    /**
     * @notice Get the current percentage of tokens held in reserve
     * @return The percent
     */
    function reservePercentage() external view returns (uint256);
}

// File: contracts/pool/IWithdrawFeePool.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

/**
 * @notice For pools that can charge an early withdrawal fee
 */
interface IWithdrawFeePool {
    /**
     * @notice Log when the fee period changes
     * @param feePeriod The new fee period
     */
    event FeePeriodChanged(uint256 feePeriod);

    /**
     * @notice Log when the fee percentage changes
     * @param feePercentage The new percentage
     */
    event FeePercentageChanged(uint256 feePercentage);

    /**
     * @notice Set the new fee period
     * @param feePeriod_ The new fee period
     */
    function setFeePeriod(uint256 feePeriod_) external;

    /**
     * @notice Set the new fee percentage
     * @param feePercentage_ The new percentage
     */
    function setFeePercentage(uint256 feePercentage_) external;

    /**
     * @notice Get the period of time that a withdrawal will be considered early
     * @notice An early withdrawal gets charged a fee
     * @notice The period starts from the time of the last deposit for an account
     * @return The time in seconds
     */
    function feePeriod() external view returns (uint256);

    /**
     * @notice Get the percentage of a withdrawal that is charged as a fee
     * @return The percentage
     */
    function feePercentage() external view returns (uint256);

    /**
     * @notice Check if caller will be charged early withdrawal fee
     * @return `true` when fee will apply, `false` when it won't
     */
    function isEarlyRedeem() external view returns (bool);
}

// File: contracts/pool/ILockingPool.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

/**
 * @notice For pools that can be locked and unlocked in emergencies
 */
interface ILockingPool {
    /** @notice Log when deposits are locked */
    event AddLiquidityLocked();

    /** @notice Log when deposits are unlocked */
    event AddLiquidityUnlocked();

    /** @notice Log when withdrawals are locked */
    event RedeemLocked();

    /** @notice Log when withdrawals are unlocked */
    event RedeemUnlocked();

    /** @notice Lock deposits and withdrawals */
    function emergencyLock() external;

    /** @notice Unlock deposits and withdrawals */
    function emergencyUnlock() external;

    /** @notice Lock deposits */
    function emergencyLockAddLiquidity() external;

    /** @notice Unlock deposits */
    function emergencyUnlockAddLiquidity() external;

    /** @notice Lock withdrawals */
    function emergencyLockRedeem() external;

    /** @notice Unlock withdrawals */
    function emergencyUnlockRedeem() external;
}

// File: contracts/pool/IPoolToken.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IDetailedERC20} from "contracts/common/Imports.sol";

/**
 * @notice For pools that locked value between accounts
 * @dev Shares are accounted for using the `APT` token
 */
interface IPoolToken {
    /**
     * @notice Log a token deposit
     * @param sender Address of the depositor account
     * @param token Token deposited
     * @param tokenAmount The amount of tokens deposited
     * @param aptMintAmount Number of shares received
     * @param tokenEthValue Total value of the deposit
     * @param totalEthValueLocked Total value of the pool
     */
    event DepositedAPT(
        address indexed sender,
        IDetailedERC20 token,
        uint256 tokenAmount,
        uint256 aptMintAmount,
        uint256 tokenEthValue,
        uint256 totalEthValueLocked
    );

    /**
     * @notice Log a token withdrawal
     * @param sender Address of the withdrawal account
     * @param token Token withdrawn
     * @param redeemedTokenAmount The amount of tokens withdrawn
     * @param aptRedeemAmount Number of shares redeemed
     * @param tokenEthValue Total value of the withdrawal
     * @param totalEthValueLocked Total value of the pool
     */
    event RedeemedAPT(
        address indexed sender,
        IDetailedERC20 token,
        uint256 redeemedTokenAmount,
        uint256 aptRedeemAmount,
        uint256 tokenEthValue,
        uint256 totalEthValueLocked
    );

    /**
     * @notice Add liquidity for a share of the pool
     * @param amount Amount to deposit of the underlying stablecoin
     */
    function addLiquidity(uint256 amount) external;

    /**
     * @notice Redeem shares of the pool to withdraw liquidity
     * @param tokenAmount The amount of shares to redeem
     */
    function redeem(uint256 tokenAmount) external;

    /**
     * @notice Determine the share received for a deposit
     * @param depositAmount The size of the deposit
     * @return The number of shares
     */
    function calculateMintAmount(uint256 depositAmount)
        external
        view
        returns (uint256);

    /**
     * @notice How many tokens can be withdrawn with an amount of shares
     * @notice Accounts for early withdrawal fee
     * @param aptAmount The amount of shares
     * @return The amount of tokens
     */
    function getUnderlyerAmountWithFee(uint256 aptAmount)
        external
        view
        returns (uint256);

    /**
     * @notice How many tokens can be withdrawn with an amount of shares
     * @param aptAmount The amount of shares
     * @return The amount of tokens
     */
    function getUnderlyerAmount(uint256 aptAmount)
        external
        view
        returns (uint256);

    /**
     * @notice Get the total USD value of an amount of shares
     * @param aptAmount The amount of shares
     * @return The total USD value of the shares
     */
    function getAPTValue(uint256 aptAmount) external view returns (uint256);
}

// File: contracts/pool/ILiquidityPoolV2.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IDetailedERC20} from "contracts/common/Imports.sol";

/**
 * @notice For contracts that hold tokens and track the value locked
 */
interface ILiquidityPoolV2 {
    /**
     * @notice The token held by the pool
     * @return The token address
     */
    function underlyer() external view returns (IDetailedERC20);

    /**
     * @notice Get the total USD value locked in the pool
     * @return The total USD value
     */
    function getPoolTotalValue() external view returns (uint256);

    /**
     * @notice Get the total USD value of an amount of tokens
     * @param underlyerAmount The amount of tokens
     * @return The total USD value
     */
    function getValueFromUnderlyerAmount(uint256 underlyerAmount)
        external
        view
        returns (uint256);

    /**
     * @notice Get the USD price of the token held by the pool
     * @return The price
     */
    function getUnderlyerPrice() external view returns (uint256);
}

// File: contracts/registry/IAddressRegistryV2.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

/**
 * @notice The address registry has two important purposes, one which
 * is fairly concrete and another abstract.
 *
 * 1. The registry enables components of the APY.Finance system
 * and external systems to retrieve core addresses reliably
 * even when the functionality may move to a different
 * address.
 *
 * 2. The registry also makes explicit which contracts serve
 * as primary entrypoints for interacting with different
 * components.  Not every contract is registered here, only
 * the ones properly deserving of an identifier.  This helps
 * define explicit boundaries between groups of contracts,
 * each of which is logically cohesive.
 */
interface IAddressRegistryV2 {
    /**
     * @notice Log when a new address is registered
     * @param id The ID of the new address
     * @param _address The new address
     */
    event AddressRegistered(bytes32 id, address _address);

    /**
     * @notice Log when an address is removed from the registry
     * @param id The ID of the address
     * @param _address The address
     */
    event AddressDeleted(bytes32 id, address _address);

    /**
     * @notice Register address with identifier
     * @dev Using an existing ID will replace the old address with new
     * @dev Currently there is no way to remove an ID, as attempting to
     * register the zero address will revert.
     */
    function registerAddress(bytes32 id, address address_) external;

    /**
     * @notice Registers multiple address at once
     * @dev Convenient method to register multiple addresses at once.
     * @param ids Ids to register addresses under
     * @param addresses Addresses to register
     */
    function registerMultipleAddresses(
        bytes32[] calldata ids,
        address[] calldata addresses
    ) external;

    /**
     * @notice Removes a registered id and it's associated address
     * @dev Delete the address corresponding to the identifier Time-complexity is O(n) where n is the length of `_idList`.
     * @param id ID to remove along with it's associated address
     */
    function deleteAddress(bytes32 id) external;

    /**
     * @notice Returns the list of all registered identifiers.
     * @return List of identifiers
     */
    function getIds() external view returns (bytes32[] memory);

    /**
     * @notice Returns the list of all registered identifiers
     * @param id Component identifier
     * @return The current address represented by an identifier
     */
    function getAddress(bytes32 id) external view returns (address);

    /**
     * @notice Returns the TVL Manager Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return TVL Manager Address
     */
    function tvlManagerAddress() external view returns (address);

    /**
     * @notice Returns the Chainlink Registry Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return Chainlink Registry Address
     */
    function chainlinkRegistryAddress() external view returns (address);

    /**
     * @notice Returns the DAI Pool Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return DAI Pool Address
     */
    function daiPoolAddress() external view returns (address);

    /**
     * @notice Returns the USDC Pool Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return USDC Pool Address
     */
    function usdcPoolAddress() external view returns (address);

    /**
     * @notice Returns the USDT Pool Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return USDT Pool Address
     */
    function usdtPoolAddress() external view returns (address);

    /**
     * @notice Returns the MAPT Pool Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return MAPT Pool Address
     */
    function mAptAddress() external view returns (address);

    /**
     * @notice Returns the LP Account Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return LP Account Address
     */
    function lpAccountAddress() external view returns (address);

    /**
     * @notice Returns the LP Safe Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return LP Safe Address
     */
    function lpSafeAddress() external view returns (address);

    /**
     * @notice Returns the Admin Safe Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return Admin Safe Address
     */
    function adminSafeAddress() external view returns (address);

    /**
     * @notice Returns the Emergency Safe Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return Emergency Safe Address
     */
    function emergencySafeAddress() external view returns (address);

    /**
     * @notice Returns the Oracle Adapter Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return Oracle Adapter Address
     */
    function oracleAdapterAddress() external view returns (address);

    /**
     * @notice Returns the ERC20 Allocation Address
     * @dev Not just a helper function, this makes explicit a key ID for the system
     * @return ERC20 Allocation Address
     */
    function erc20AllocationAddress() external view returns (address);
}

// File: contracts/tvl/IErc20Allocation.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IERC20, IDetailedERC20} from "contracts/common/Imports.sol";

/**
 * @notice An asset allocation for tokens not stored in a protocol
 * @dev `IZap`s and `ISwap`s register these separate from other allocations
 * @dev Unlike other asset allocations, new tokens can be added or removed
 * @dev Registration can override `symbol` and `decimals` manually because
 * they are optional in the ERC20 standard.
 */
interface IErc20Allocation {
    /** @notice Log when an ERC20 allocation is registered */
    event Erc20TokenRegistered(IERC20 token, string symbol, uint8 decimals);

    /** @notice Log when an ERC20 allocation is removed */
    event Erc20TokenRemoved(IERC20 token);

    /**
     * @notice Add a new ERC20 token to the asset allocation
     * @dev Should not allow duplicate tokens
     * @param token The new token
     */
    function registerErc20Token(IDetailedERC20 token) external;

    /**
     * @notice Add a new ERC20 token to the asset allocation
     * @dev Should not allow duplicate tokens
     * @param token The new token
     * @param symbol Override the token symbol
     */
    function registerErc20Token(IDetailedERC20 token, string calldata symbol)
        external;

    /**
     * @notice Add a new ERC20 token to the asset allocation
     * @dev Should not allow duplicate tokens
     * @param token The new token
     * @param symbol Override the token symbol
     * @param decimals Override the token decimals
     */
    function registerErc20Token(
        IERC20 token,
        string calldata symbol,
        uint8 decimals
    ) external;

    /**
     * @notice Remove an ERC20 token from the asset allocation
     * @param token The token to remove
     */
    function removeErc20Token(IERC20 token) external;

    /**
     * @notice Check if an ERC20 token is registered
     * @param token The token to check
     * @return `true` if the token is registered, `false` otherwise
     */
    function isErc20TokenRegistered(IERC20 token) external view returns (bool);

    /**
     * @notice Check if multiple ERC20 tokens are ALL registered
     * @param tokens An array of tokens to check
     * @return `true` if every token is registered, `false` otherwise
     */
    function isErc20TokenRegistered(IERC20[] calldata tokens)
        external
        view
        returns (bool);
}

// File: contracts/tvl/IChainlinkRegistry.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

/**
 * @notice Interface used by Chainlink to aggregate allocations and compute TVL
 */
interface IChainlinkRegistry {
    /**
     * @notice Get all IDs from registered asset allocations
     * @notice Each ID is a unique asset allocation and token index pair
     * @dev Should contain no duplicate IDs
     * @return list of all IDs
     */
    function getAssetAllocationIds() external view returns (bytes32[] memory);

    /**
     * @notice Get the LP Account's balance for an asset allocation ID
     * @param allocationId The ID to fetch the balance for
     * @return The balance for the LP Account
     */
    function balanceOf(bytes32 allocationId) external view returns (uint256);

    /**
     * @notice Get the symbol for an allocation ID's underlying token
     * @param allocationId The ID to fetch the symbol for
     * @return The underlying token symbol
     */
    function symbolOf(bytes32 allocationId)
        external
        view
        returns (string memory);

    /**
     * @notice Get the decimals for an allocation ID's underlying token
     * @param allocationId The ID to fetch the decimals for
     * @return The underlying token decimals
     */
    function decimalsOf(bytes32 allocationId) external view returns (uint256);
}

// File: contracts/tvl/IAssetAllocationRegistry.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {IAssetAllocation} from "contracts/common/Imports.sol";

/**
 * @notice For managing a collection of `IAssetAllocation` contracts
 */
interface IAssetAllocationRegistry {
    /** @notice Log when an asset allocation is registered */
    event AssetAllocationRegistered(IAssetAllocation assetAllocation);

    /** @notice Log when an asset allocation is removed */
    event AssetAllocationRemoved(string name);

    /**
     * @notice Add a new asset allocation to the registry
     * @dev Should not allow duplicate asset allocations
     * @param assetAllocation The new asset allocation
     */
    function registerAssetAllocation(IAssetAllocation assetAllocation) external;

    /**
     * @notice Remove an asset allocation from the registry
     * @param name The name of the asset allocation (see `INameIdentifier`)
     */
    function removeAssetAllocation(string memory name) external;

    /**
     * @notice Check if multiple asset allocations are ALL registered
     * @param allocationNames An array of asset allocation names
     * @return `true` if every allocation is registered, otherwise `false`
     */
    function isAssetAllocationRegistered(string[] calldata allocationNames)
        external
        view
        returns (bool);

    /**
     * @notice Get the registered asset allocation with a given name
     * @param name The asset allocation name
     * @return The asset allocation
     */
    function getAssetAllocation(string calldata name)
        external
        view
        returns (IAssetAllocation);
}

// File: contracts/tvl/AssetAllocationBase.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {IAssetAllocation} from "contracts/common/Imports.sol";

abstract contract AssetAllocationBase is IAssetAllocation {
    function numberOfTokens() external view override returns (uint256) {
        return tokens().length;
    }

    function symbolOf(uint8 tokenIndex)
        public
        view
        override
        returns (string memory)
    {
        return tokens()[tokenIndex].symbol;
    }

    function decimalsOf(uint8 tokenIndex) public view override returns (uint8) {
        return tokens()[tokenIndex].decimals;
    }

    function addressOf(uint8 tokenIndex) public view returns (address) {
        return tokens()[tokenIndex].token;
    }

    function tokens() public view virtual override returns (TokenData[] memory);
}

// File: contracts/tvl/ImmutableAssetAllocation.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {Address} from "contracts/libraries/Imports.sol";
import {AssetAllocationBase} from "./AssetAllocationBase.sol";

/**
 * @notice Asset allocation with underlying tokens that cannot be added/removed
 */
abstract contract ImmutableAssetAllocation is AssetAllocationBase {
    using Address for address;

    constructor() public {
        _validateTokens(_getTokenData());
    }

    function tokens() public view override returns (TokenData[] memory) {
        TokenData[] memory tokens_ = _getTokenData();
        return tokens_;
    }

    /**
     * @notice Verifies that a `TokenData` array works with the `TvlManager`
     * @dev Reverts when there is invalid `TokenData`
     * @param tokens_ The array of `TokenData`
     */
    function _validateTokens(TokenData[] memory tokens_) internal view virtual {
        // length restriction due to encoding logic for allocation IDs
        require(tokens_.length < type(uint8).max, "TOO_MANY_TOKENS");
        for (uint256 i = 0; i < tokens_.length; i++) {
            address token = tokens_[i].token;
            _validateTokenAddress(token);
            string memory symbol = tokens_[i].symbol;
            require(bytes(symbol).length != 0, "INVALID_SYMBOL");
        }
        // TODO: check for duplicate tokens
    }

    /**
     * @notice Verify that a token is a contract
     * @param token The token to verify
     */
    function _validateTokenAddress(address token) internal view virtual {
        require(token.isContract(), "INVALID_ADDRESS");
    }

    /**
     * @notice Get the immutable array of underlying `TokenData`
     * @dev Should be implemented in child contracts with a hardcoded array
     * @return The array of `TokenData`
     */
    function _getTokenData() internal pure virtual returns (TokenData[] memory);
}

// File: contracts/tvl/Erc20Allocation.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;
pragma experimental ABIEncoderV2;

import {
    IERC20,
    IDetailedERC20,
    AccessControl,
    INameIdentifier,
    ReentrancyGuard
} from "contracts/common/Imports.sol";
import {Address, EnumerableSet} from "contracts/libraries/Imports.sol";
import {IAddressRegistryV2} from "contracts/registry/Imports.sol";
import {ILockingOracle} from "contracts/oracle/Imports.sol";

import {IErc20Allocation} from "./IErc20Allocation.sol";
import {AssetAllocationBase} from "./AssetAllocationBase.sol";

abstract contract Erc20AllocationConstants is INameIdentifier {
    string public constant override NAME = "erc20Allocation";
}

contract Erc20Allocation is
    IErc20Allocation,
    AssetAllocationBase,
    Erc20AllocationConstants,
    AccessControl,
    ReentrancyGuard
{
    using Address for address;
    using EnumerableSet for EnumerableSet.AddressSet;

    IAddressRegistryV2 public addressRegistry;

    EnumerableSet.AddressSet private _tokenAddresses;
    mapping(address => TokenData) private _tokenToData;

    /** @notice Log when the address registry is changed */
    event AddressRegistryChanged(address);

    constructor(address addressRegistry_) public {
        _setAddressRegistry(addressRegistry_);
        _setupRole(DEFAULT_ADMIN_ROLE, addressRegistry.emergencySafeAddress());
        _setupRole(EMERGENCY_ROLE, addressRegistry.emergencySafeAddress());
        _setupRole(ADMIN_ROLE, addressRegistry.adminSafeAddress());
        _setupRole(CONTRACT_ROLE, addressRegistry.mAptAddress());
    }

    /**
     * @notice Set the new address registry
     * @param addressRegistry_ The new address registry
     */
    function emergencySetAddressRegistry(address addressRegistry_)
        external
        nonReentrant
        onlyEmergencyRole
    {
        _setAddressRegistry(addressRegistry_);
    }

    function registerErc20Token(IDetailedERC20 token)
        external
        override
        nonReentrant
        onlyAdminOrContractRole
    {
        string memory symbol = token.symbol();
        uint8 decimals = token.decimals();
        _registerErc20Token(token, symbol, decimals);
    }

    function registerErc20Token(IDetailedERC20 token, string calldata symbol)
        external
        override
        nonReentrant
        onlyAdminRole
    {
        uint8 decimals = token.decimals();
        _registerErc20Token(token, symbol, decimals);
    }

    function registerErc20Token(
        IERC20 token,
        string calldata symbol,
        uint8 decimals
    ) external override nonReentrant onlyAdminRole {
        _registerErc20Token(token, symbol, decimals);
    }

    function removeErc20Token(IERC20 token)
        external
        override
        nonReentrant
        onlyAdminRole
    {
        _tokenAddresses.remove(address(token));
        delete _tokenToData[address(token)];

        _lockOracleAdapter();

        emit Erc20TokenRemoved(token);
    }

    function isErc20TokenRegistered(IERC20 token)
        external
        view
        override
        returns (bool)
    {
        return _tokenAddresses.contains(address(token));
    }

    function isErc20TokenRegistered(IERC20[] calldata tokens)
        external
        view
        override
        returns (bool)
    {
        uint256 length = tokens.length;
        for (uint256 i = 0; i < length; i++) {
            if (!_tokenAddresses.contains(address(tokens[i]))) {
                return false;
            }
        }

        return true;
    }

    function balanceOf(address account, uint8 tokenIndex)
        external
        view
        override
        returns (uint256)
    {
        address token = addressOf(tokenIndex);
        return IERC20(token).balanceOf(account);
    }

    function tokens() public view override returns (TokenData[] memory) {
        TokenData[] memory _tokens = new TokenData[](_tokenAddresses.length());
        for (uint256 i = 0; i < _tokens.length; i++) {
            address tokenAddress = _tokenAddresses.at(i);
            _tokens[i] = _tokenToData[tokenAddress];
        }
        return _tokens;
    }

    function _setAddressRegistry(address addressRegistry_) internal {
        require(addressRegistry_.isContract(), "INVALID_ADDRESS");
        addressRegistry = IAddressRegistryV2(addressRegistry_);
        emit AddressRegistryChanged(addressRegistry_);
    }

    function _registerErc20Token(
        IERC20 token,
        string memory symbol,
        uint8 decimals
    ) internal {
        require(address(token).isContract(), "INVALID_ADDRESS");
        require(bytes(symbol).length != 0, "INVALID_SYMBOL");
        _tokenAddresses.add(address(token));
        _tokenToData[address(token)] = TokenData(
            address(token),
            symbol,
            decimals
        );

        _lockOracleAdapter();

        emit Erc20TokenRegistered(token, symbol, decimals);
    }

    /**
     * @notice Lock the `OracleAdapter` for the default period of time
     * @dev Locking protects against front-running while Chainlink updates
     */
    function _lockOracleAdapter() internal {
        ILockingOracle oracleAdapter =
            ILockingOracle(addressRegistry.oracleAdapterAddress());
        oracleAdapter.lock();
    }
}

// File: contracts/oracle/FluxAggregator.sol



/**
SPDX-License-Identifier: UNLICENSED
----------------------------------
---- APY.Finance comments --------
----------------------------------

Due to pragma being fixed at 0.6.6, we had to copy over this contract
and fix the imports.

original path: @chainlink/contracts/src/v0.6/FluxAggregator.sol
npm package version: 0.0.9
 */
pragma solidity 0.6.11;

import "@chainlink/contracts/src/v0.6/Median.sol";
import "@chainlink/contracts/src/v0.6/Owned.sol";
import "@chainlink/contracts/src/v0.6/SafeMath128.sol";
import "@chainlink/contracts/src/v0.6/SafeMath32.sol";
import "@chainlink/contracts/src/v0.6/SafeMath64.sol";
import "@chainlink/contracts/src/v0.6/interfaces/AggregatorV2V3Interface.sol";
import "@chainlink/contracts/src/v0.6/interfaces/AggregatorValidatorInterface.sol";
import "@chainlink/contracts/src/v0.6/interfaces/LinkTokenInterface.sol";
import "@chainlink/contracts/src/v0.6/vendor/SafeMath.sol";

/* solhint-disable */
/**
 * @title The Prepaid Aggregator contract
 * @notice Handles aggregating data pushed in from off-chain, and unlocks
 * payment for oracles as they report. Oracles' submissions are gathered in
 * rounds, with each round aggregating the submissions for each oracle into a
 * single answer. The latest aggregated answer is exposed as well as historical
 * answers and their updated at timestamp.
 */
contract FluxAggregator is AggregatorV2V3Interface, Owned {
    using SafeMath for uint256;
    using SafeMath128 for uint128;
    using SafeMath64 for uint64;
    using SafeMath32 for uint32;

    struct Round {
        int256 answer;
        uint64 startedAt;
        uint64 updatedAt;
        uint32 answeredInRound;
    }

    struct RoundDetails {
        int256[] submissions;
        uint32 maxSubmissions;
        uint32 minSubmissions;
        uint32 timeout;
        uint128 paymentAmount;
    }

    struct OracleStatus {
        uint128 withdrawable;
        uint32 startingRound;
        uint32 endingRound;
        uint32 lastReportedRound;
        uint32 lastStartedRound;
        int256 latestSubmission;
        uint16 index;
        address admin;
        address pendingAdmin;
    }

    struct Requester {
        bool authorized;
        uint32 delay;
        uint32 lastStartedRound;
    }

    struct Funds {
        uint128 available;
        uint128 allocated;
    }

    LinkTokenInterface public linkToken;
    AggregatorValidatorInterface public validator;

    // Round related params
    uint128 public paymentAmount;
    uint32 public maxSubmissionCount;
    uint32 public minSubmissionCount;
    uint32 public restartDelay;
    uint32 public timeout;
    uint8 public override decimals;
    string public override description;

    int256 public immutable minSubmissionValue;
    int256 public immutable maxSubmissionValue;

    uint256 public constant override version = 3;

    /**
     * @notice To ensure owner isn't withdrawing required funds as oracles are
     * submitting updates, we enforce that the contract maintains a minimum
     * reserve of RESERVE_ROUNDS * oracleCount() LINK earmarked for payment to
     * oracles. (Of course, this doesn't prevent the contract from running out of
     * funds without the owner's intervention.)
     */
    uint256 private constant RESERVE_ROUNDS = 2;
    uint256 private constant MAX_ORACLE_COUNT = 77;
    uint32 private constant ROUND_MAX = 2**32 - 1;
    uint256 private constant VALIDATOR_GAS_LIMIT = 100000;
    // An error specific to the Aggregator V3 Interface, to prevent possible
    // confusion around accidentally reading unset values as reported values.
    string private constant V3_NO_DATA_ERROR = "No data present";

    uint32 private reportingRoundId;
    uint32 internal latestRoundId;
    mapping(address => OracleStatus) private oracles;
    mapping(uint32 => Round) internal rounds;
    mapping(uint32 => RoundDetails) internal details;
    mapping(address => Requester) internal requesters;
    address[] private oracleAddresses;
    Funds private recordedFunds;

    event AvailableFundsUpdated(uint256 indexed amount);
    event RoundDetailsUpdated(
        uint128 indexed paymentAmount,
        uint32 indexed minSubmissionCount,
        uint32 indexed maxSubmissionCount,
        uint32 restartDelay,
        uint32 timeout // measured in seconds
    );
    event OraclePermissionsUpdated(
        address indexed oracle,
        bool indexed whitelisted
    );
    event OracleAdminUpdated(address indexed oracle, address indexed newAdmin);
    event OracleAdminUpdateRequested(
        address indexed oracle,
        address admin,
        address newAdmin
    );
    event SubmissionReceived(
        int256 indexed submission,
        uint32 indexed round,
        address indexed oracle
    );
    event RequesterPermissionsSet(
        address indexed requester,
        bool authorized,
        uint32 delay
    );
    event ValidatorUpdated(address indexed previous, address indexed current);

    /**
     * @notice set up the aggregator with initial configuration
     * @param _link The address of the LINK token
     * @param _paymentAmount The amount paid of LINK paid to each oracle per submission, in wei (units of 10⁻¹⁸ LINK)
     * @param _timeout is the number of seconds after the previous round that are
     * allowed to lapse before allowing an oracle to skip an unfinished round
     * @param _validator is an optional contract address for validating
     * external validation of answers
     * @param _minSubmissionValue is an immutable check for a lower bound of what
     * submission values are accepted from an oracle
     * @param _maxSubmissionValue is an immutable check for an upper bound of what
     * submission values are accepted from an oracle
     * @param _decimals represents the number of decimals to offset the answer by
     * @param _description a short description of what is being reported
     */
    constructor(
        address _link,
        uint128 _paymentAmount,
        uint32 _timeout,
        address _validator,
        int256 _minSubmissionValue,
        int256 _maxSubmissionValue,
        uint8 _decimals,
        string memory _description
    ) public {
        linkToken = LinkTokenInterface(_link);
        updateFutureRounds(_paymentAmount, 0, 0, 0, _timeout);
        setValidator(_validator);
        minSubmissionValue = _minSubmissionValue;
        maxSubmissionValue = _maxSubmissionValue;
        decimals = _decimals;
        description = _description;
        rounds[0].updatedAt = uint64(block.timestamp.sub(uint256(_timeout)));
    }

    /**
     * @notice called by oracles when they have witnessed a need to update
     * @param _roundId is the ID of the round this submission pertains to
     * @param _submission is the updated data that the oracle is submitting
     */
    function submit(uint256 _roundId, int256 _submission) external {
        bytes memory error = validateOracleRound(msg.sender, uint32(_roundId));
        require(
            _submission >= minSubmissionValue,
            "value below minSubmissionValue"
        );
        require(
            _submission <= maxSubmissionValue,
            "value above maxSubmissionValue"
        );
        require(error.length == 0, string(error));

        oracleInitializeNewRound(uint32(_roundId));
        recordSubmission(_submission, uint32(_roundId));
        (bool updated, int256 newAnswer) = updateRoundAnswer(uint32(_roundId));
        payOracle(uint32(_roundId));
        deleteRoundDetails(uint32(_roundId));
        if (updated) {
            validateAnswer(uint32(_roundId), newAnswer);
        }
    }

    /**
     * @notice called by the owner to remove and add new oracles as well as
     * update the round related parameters that pertain to total oracle count
     * @param _removed is the list of addresses for the new Oracles being removed
     * @param _added is the list of addresses for the new Oracles being added
     * @param _addedAdmins is the admin addresses for the new respective _added
     * list. Only this address is allowed to access the respective oracle's funds
     * @param _minSubmissions is the new minimum submission count for each round
     * @param _maxSubmissions is the new maximum submission count for each round
     * @param _restartDelay is the number of rounds an Oracle has to wait before
     * they can initiate a round
     */
    function changeOracles(
        address[] calldata _removed,
        address[] calldata _added,
        address[] calldata _addedAdmins,
        uint32 _minSubmissions,
        uint32 _maxSubmissions,
        uint32 _restartDelay
    ) external onlyOwner() {
        for (uint256 i = 0; i < _removed.length; i++) {
            removeOracle(_removed[i]);
        }

        require(
            _added.length == _addedAdmins.length,
            "need same oracle and admin count"
        );
        require(
            uint256(oracleCount()).add(_added.length) <= MAX_ORACLE_COUNT,
            "max oracles allowed"
        );

        for (uint256 i = 0; i < _added.length; i++) {
            addOracle(_added[i], _addedAdmins[i]);
        }

        updateFutureRounds(
            paymentAmount,
            _minSubmissions,
            _maxSubmissions,
            _restartDelay,
            timeout
        );
    }

    /**
     * @notice update the round and payment related parameters for subsequent
     * rounds
     * @param _paymentAmount is the payment amount for subsequent rounds
     * @param _minSubmissions is the new minimum submission count for each round
     * @param _maxSubmissions is the new maximum submission count for each round
     * @param _restartDelay is the number of rounds an Oracle has to wait before
     * they can initiate a round
     */
    function updateFutureRounds(
        uint128 _paymentAmount,
        uint32 _minSubmissions,
        uint32 _maxSubmissions,
        uint32 _restartDelay,
        uint32 _timeout
    ) public onlyOwner() {
        uint32 oracleNum = oracleCount(); // Save on storage reads
        require(
            _maxSubmissions >= _minSubmissions,
            "max must equal/exceed min"
        );
        require(oracleNum >= _maxSubmissions, "max cannot exceed total");
        require(
            oracleNum == 0 || oracleNum > _restartDelay,
            "delay cannot exceed total"
        );
        require(
            recordedFunds.available >= requiredReserve(_paymentAmount),
            "insufficient funds for payment"
        );
        if (oracleCount() > 0) {
            require(_minSubmissions > 0, "min must be greater than 0");
        }

        paymentAmount = _paymentAmount;
        minSubmissionCount = _minSubmissions;
        maxSubmissionCount = _maxSubmissions;
        restartDelay = _restartDelay;
        timeout = _timeout;

        emit RoundDetailsUpdated(
            paymentAmount,
            _minSubmissions,
            _maxSubmissions,
            _restartDelay,
            _timeout
        );
    }

    /**
     * @notice the amount of payment yet to be withdrawn by oracles
     */
    function allocatedFunds() external view returns (uint128) {
        return recordedFunds.allocated;
    }

    /**
     * @notice the amount of future funding available to oracles
     */
    function availableFunds() external view returns (uint128) {
        return recordedFunds.available;
    }

    /**
     * @notice recalculate the amount of LINK available for payouts
     */
    function updateAvailableFunds() public {
        Funds memory funds = recordedFunds;

        uint256 nowAvailable =
            linkToken.balanceOf(address(this)).sub(funds.allocated);

        if (funds.available != nowAvailable) {
            recordedFunds.available = uint128(nowAvailable);
            emit AvailableFundsUpdated(nowAvailable);
        }
    }

    /**
     * @notice returns the number of oracles
     */
    function oracleCount() public view returns (uint8) {
        return uint8(oracleAddresses.length);
    }

    /**
     * @notice returns an array of addresses containing the oracles on contract
     */
    function getOracles() external view returns (address[] memory) {
        return oracleAddresses;
    }

    /**
     * @notice get the most recently reported answer
     *
     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
     * answer has been reached, it will simply return 0. Either wait to point to
     * an already answered Aggregator or use the recommended latestRoundData
     * instead which includes better verification information.
     */
    function latestAnswer() public view virtual override returns (int256) {
        return rounds[latestRoundId].answer;
    }

    /**
     * @notice get the most recent updated at timestamp
     *
     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
     * answer has been reached, it will simply return 0. Either wait to point to
     * an already answered Aggregator or use the recommended latestRoundData
     * instead which includes better verification information.
     */
    function latestTimestamp() public view virtual override returns (uint256) {
        return rounds[latestRoundId].updatedAt;
    }

    /**
     * @notice get the ID of the last updated round
     *
     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
     * answer has been reached, it will simply return 0. Either wait to point to
     * an already answered Aggregator or use the recommended latestRoundData
     * instead which includes better verification information.
     */
    function latestRound() public view virtual override returns (uint256) {
        return latestRoundId;
    }

    /**
     * @notice get past rounds answers
     * @param _roundId the round number to retrieve the answer for
     *
     * @dev #[deprecated] Use getRoundData instead. This does not error if no
     * answer has been reached, it will simply return 0. Either wait to point to
     * an already answered Aggregator or use the recommended getRoundData
     * instead which includes better verification information.
     */
    function getAnswer(uint256 _roundId)
        public
        view
        virtual
        override
        returns (int256)
    {
        if (validRoundId(_roundId)) {
            return rounds[uint32(_roundId)].answer;
        }
        return 0;
    }

    /**
     * @notice get timestamp when an answer was last updated
     * @param _roundId the round number to retrieve the updated timestamp for
     *
     * @dev #[deprecated] Use getRoundData instead. This does not error if no
     * answer has been reached, it will simply return 0. Either wait to point to
     * an already answered Aggregator or use the recommended getRoundData
     * instead which includes better verification information.
     */
    function getTimestamp(uint256 _roundId)
        public
        view
        virtual
        override
        returns (uint256)
    {
        if (validRoundId(_roundId)) {
            return rounds[uint32(_roundId)].updatedAt;
        }
        return 0;
    }

    /**
     * @notice get data about a round. Consumers are encouraged to check
     * that they're receiving fresh data by inspecting the updatedAt and
     * answeredInRound return values.
     * @param _roundId the round ID to retrieve the round data for
     * @return roundId is the round ID for which data was retrieved
     * @return answer is the answer for the given round
     * @return startedAt is the timestamp when the round was started. This is 0
     * if the round hasn't been started yet.
     * @return updatedAt is the timestamp when the round last was updated (i.e.
     * answer was last computed)
     * @return answeredInRound is the round ID of the round in which the answer
     * was computed. answeredInRound may be smaller than roundId when the round
     * timed out. answeredInRound is equal to roundId when the round didn't time out
     * and was completed regularly.
     * @dev Note that for in-progress rounds (i.e. rounds that haven't yet received
     * maxSubmissions) answer and updatedAt may change between queries.
     */
    function getRoundData(uint80 _roundId)
        public
        view
        virtual
        override
        returns (
            uint80 roundId,
            int256 answer,
            uint256 startedAt,
            uint256 updatedAt,
            uint80 answeredInRound
        )
    {
        Round memory r = rounds[uint32(_roundId)];

        require(
            r.answeredInRound > 0 && validRoundId(_roundId),
            V3_NO_DATA_ERROR
        );

        return (
            _roundId,
            r.answer,
            r.startedAt,
            r.updatedAt,
            r.answeredInRound
        );
    }

    /**
     * @notice get data about the latest round. Consumers are encouraged to check
     * that they're receiving fresh data by inspecting the updatedAt and
     * answeredInRound return values. Consumers are encouraged to
     * use this more fully featured method over the "legacy" latestRound/
     * latestAnswer/latestTimestamp functions. Consumers are encouraged to check
     * that they're receiving fresh data by inspecting the updatedAt and
     * answeredInRound return values.
     * @return roundId is the round ID for which data was retrieved
     * @return answer is the answer for the given round
     * @return startedAt is the timestamp when the round was started. This is 0
     * if the round hasn't been started yet.
     * @return updatedAt is the timestamp when the round last was updated (i.e.
     * answer was last computed)
     * @return answeredInRound is the round ID of the round in which the answer
     * was computed. answeredInRound may be smaller than roundId when the round
     * timed out. answeredInRound is equal to roundId when the round didn't time
     * out and was completed regularly.
     * @dev Note that for in-progress rounds (i.e. rounds that haven't yet
     * received maxSubmissions) answer and updatedAt may change between queries.
     */
    function latestRoundData()
        public
        view
        virtual
        override
        returns (
            uint80 roundId,
            int256 answer,
            uint256 startedAt,
            uint256 updatedAt,
            uint80 answeredInRound
        )
    {
        return getRoundData(latestRoundId);
    }

    /**
     * @notice query the available amount of LINK for an oracle to withdraw
     */
    function withdrawablePayment(address _oracle)
        external
        view
        returns (uint256)
    {
        return oracles[_oracle].withdrawable;
    }

    /**
     * @notice transfers the oracle's LINK to another address. Can only be called
     * by the oracle's admin.
     * @param _oracle is the oracle whose LINK is transferred
     * @param _recipient is the address to send the LINK to
     * @param _amount is the amount of LINK to send
     */
    function withdrawPayment(
        address _oracle,
        address _recipient,
        uint256 _amount
    ) external {
        require(oracles[_oracle].admin == msg.sender, "only callable by admin");

        // Safe to downcast _amount because the total amount of LINK is less than 2^128.
        uint128 amount = uint128(_amount);
        uint128 available = oracles[_oracle].withdrawable;
        require(available >= amount, "insufficient withdrawable funds");

        oracles[_oracle].withdrawable = available.sub(amount);
        recordedFunds.allocated = recordedFunds.allocated.sub(amount);

        assert(linkToken.transfer(_recipient, uint256(amount)));
    }

    /**
     * @notice transfers the owner's LINK to another address
     * @param _recipient is the address to send the LINK to
     * @param _amount is the amount of LINK to send
     */
    function withdrawFunds(address _recipient, uint256 _amount)
        external
        onlyOwner()
    {
        uint256 available = uint256(recordedFunds.available);
        require(
            available.sub(requiredReserve(paymentAmount)) >= _amount,
            "insufficient reserve funds"
        );
        require(
            linkToken.transfer(_recipient, _amount),
            "token transfer failed"
        );
        updateAvailableFunds();
    }

    /**
     * @notice get the admin address of an oracle
     * @param _oracle is the address of the oracle whose admin is being queried
     */
    function getAdmin(address _oracle) external view returns (address) {
        return oracles[_oracle].admin;
    }

    /**
     * @notice transfer the admin address for an oracle
     * @param _oracle is the address of the oracle whose admin is being transferred
     * @param _newAdmin is the new admin address
     */
    function transferAdmin(address _oracle, address _newAdmin) external {
        require(oracles[_oracle].admin == msg.sender, "only callable by admin");
        oracles[_oracle].pendingAdmin = _newAdmin;

        emit OracleAdminUpdateRequested(_oracle, msg.sender, _newAdmin);
    }

    /**
     * @notice accept the admin address transfer for an oracle
     * @param _oracle is the address of the oracle whose admin is being transferred
     */
    function acceptAdmin(address _oracle) external {
        require(
            oracles[_oracle].pendingAdmin == msg.sender,
            "only callable by pending admin"
        );
        oracles[_oracle].pendingAdmin = address(0);
        oracles[_oracle].admin = msg.sender;

        emit OracleAdminUpdated(_oracle, msg.sender);
    }

    /**
     * @notice allows non-oracles to request a new round
     */
    function requestNewRound() external returns (uint80) {
        require(requesters[msg.sender].authorized, "not authorized requester");

        uint32 current = reportingRoundId;
        require(
            rounds[current].updatedAt > 0 || timedOut(current),
            "prev round must be supersedable"
        );

        uint32 newRoundId = current.add(1);
        requesterInitializeNewRound(newRoundId);
        return newRoundId;
    }

    /**
     * @notice allows the owner to specify new non-oracles to start new rounds
     * @param _requester is the address to set permissions for
     * @param _authorized is a boolean specifying whether they can start new rounds or not
     * @param _delay is the number of rounds the requester must wait before starting another round
     */
    function setRequesterPermissions(
        address _requester,
        bool _authorized,
        uint32 _delay
    ) external onlyOwner() {
        if (requesters[_requester].authorized == _authorized) return;

        if (_authorized) {
            requesters[_requester].authorized = _authorized;
            requesters[_requester].delay = _delay;
        } else {
            delete requesters[_requester];
        }

        emit RequesterPermissionsSet(_requester, _authorized, _delay);
    }

    /**
     * @notice called through LINK's transferAndCall to update available funds
     * in the same transaction as the funds were transferred to the aggregator
     * @param _data is mostly ignored. It is checked for length, to be sure
     * nothing strange is passed in.
     */
    function onTokenTransfer(
        address,
        uint256,
        bytes calldata _data
    ) external {
        require(_data.length == 0, "transfer doesn't accept calldata");
        updateAvailableFunds();
    }

    /**
     * @notice a method to provide all current info oracles need. Intended only
     * only to be callable by oracles. Not for use by contracts to read state.
     * @param _oracle the address to look up information for.
     */
    function oracleRoundState(address _oracle, uint32 _queriedRoundId)
        external
        view
        returns (
            bool _eligibleToSubmit,
            uint32 _roundId,
            int256 _latestSubmission,
            uint64 _startedAt,
            uint64 _timeout,
            uint128 _availableFunds,
            uint8 _oracleCount,
            uint128 _paymentAmount
        )
    {
        require(msg.sender == tx.origin, "off-chain reading only");

        if (_queriedRoundId > 0) {
            Round storage round = rounds[_queriedRoundId];
            RoundDetails storage details = details[_queriedRoundId];
            return (
                eligibleForSpecificRound(_oracle, _queriedRoundId),
                _queriedRoundId,
                oracles[_oracle].latestSubmission,
                round.startedAt,
                details.timeout,
                recordedFunds.available,
                oracleCount(),
                (round.startedAt > 0 ? details.paymentAmount : paymentAmount)
            );
        } else {
            return oracleRoundStateSuggestRound(_oracle);
        }
    }

    /**
     * @notice method to update the address which does external data validation.
     * @param _newValidator designates the address of the new validation contract.
     */
    function setValidator(address _newValidator) public onlyOwner() {
        address previous = address(validator);

        if (previous != _newValidator) {
            validator = AggregatorValidatorInterface(_newValidator);

            emit ValidatorUpdated(previous, _newValidator);
        }
    }

    /**
     * Private
     */

    function initializeNewRound(uint32 _roundId) private {
        updateTimedOutRoundInfo(_roundId.sub(1));

        reportingRoundId = _roundId;
        RoundDetails memory nextDetails =
            RoundDetails(
                new int256[](0),
                maxSubmissionCount,
                minSubmissionCount,
                timeout,
                paymentAmount
            );
        details[_roundId] = nextDetails;
        rounds[_roundId].startedAt = uint64(block.timestamp);

        emit NewRound(_roundId, msg.sender, rounds[_roundId].startedAt);
    }

    function oracleInitializeNewRound(uint32 _roundId) private {
        if (!newRound(_roundId)) return;
        uint256 lastStarted = oracles[msg.sender].lastStartedRound; // cache storage reads
        if (_roundId <= lastStarted + restartDelay && lastStarted != 0) return;

        initializeNewRound(_roundId);

        oracles[msg.sender].lastStartedRound = _roundId;
    }

    function requesterInitializeNewRound(uint32 _roundId) private {
        if (!newRound(_roundId)) return;
        uint256 lastStarted = requesters[msg.sender].lastStartedRound; // cache storage reads
        require(
            _roundId > lastStarted + requesters[msg.sender].delay ||
                lastStarted == 0,
            "must delay requests"
        );

        initializeNewRound(_roundId);

        requesters[msg.sender].lastStartedRound = _roundId;
    }

    function updateTimedOutRoundInfo(uint32 _roundId) private {
        if (!timedOut(_roundId)) return;

        uint32 prevId = _roundId.sub(1);
        rounds[_roundId].answer = rounds[prevId].answer;
        rounds[_roundId].answeredInRound = rounds[prevId].answeredInRound;
        rounds[_roundId].updatedAt = uint64(block.timestamp);

        delete details[_roundId];
    }

    function eligibleForSpecificRound(address _oracle, uint32 _queriedRoundId)
        private
        view
        returns (bool _eligible)
    {
        if (rounds[_queriedRoundId].startedAt > 0) {
            return
                acceptingSubmissions(_queriedRoundId) &&
                validateOracleRound(_oracle, _queriedRoundId).length == 0;
        } else {
            return
                delayed(_oracle, _queriedRoundId) &&
                validateOracleRound(_oracle, _queriedRoundId).length == 0;
        }
    }

    function oracleRoundStateSuggestRound(address _oracle)
        private
        view
        returns (
            bool _eligibleToSubmit,
            uint32 _roundId,
            int256 _latestSubmission,
            uint64 _startedAt,
            uint64 _timeout,
            uint128 _availableFunds,
            uint8 _oracleCount,
            uint128 _paymentAmount
        )
    {
        Round storage round = rounds[0];
        OracleStatus storage oracle = oracles[_oracle];

        bool shouldSupersede =
            oracle.lastReportedRound == reportingRoundId ||
                !acceptingSubmissions(reportingRoundId);
        // Instead of nudging oracles to submit to the next round, the inclusion of
        // the shouldSupersede bool in the if condition pushes them towards
        // submitting in a currently open round.
        if (supersedable(reportingRoundId) && shouldSupersede) {
            _roundId = reportingRoundId.add(1);
            round = rounds[_roundId];

            _paymentAmount = paymentAmount;
            _eligibleToSubmit = delayed(_oracle, _roundId);
        } else {
            _roundId = reportingRoundId;
            round = rounds[_roundId];

            _paymentAmount = details[_roundId].paymentAmount;
            _eligibleToSubmit = acceptingSubmissions(_roundId);
        }

        if (validateOracleRound(_oracle, _roundId).length != 0) {
            _eligibleToSubmit = false;
        }

        return (
            _eligibleToSubmit,
            _roundId,
            oracle.latestSubmission,
            round.startedAt,
            details[_roundId].timeout,
            recordedFunds.available,
            oracleCount(),
            _paymentAmount
        );
    }

    function updateRoundAnswer(uint32 _roundId)
        internal
        returns (bool, int256)
    {
        if (
            details[_roundId].submissions.length <
            details[_roundId].minSubmissions
        ) {
            return (false, 0);
        }

        int256 newAnswer =
            Median.calculateInplace(details[_roundId].submissions);
        rounds[_roundId].answer = newAnswer;
        rounds[_roundId].updatedAt = uint64(block.timestamp);
        rounds[_roundId].answeredInRound = _roundId;
        latestRoundId = _roundId;

        emit AnswerUpdated(newAnswer, _roundId, now);

        return (true, newAnswer);
    }

    function validateAnswer(uint32 _roundId, int256 _newAnswer) private {
        AggregatorValidatorInterface av = validator; // cache storage reads
        if (address(av) == address(0)) return;

        uint32 prevRound = _roundId.sub(1);
        uint32 prevAnswerRoundId = rounds[prevRound].answeredInRound;
        int256 prevRoundAnswer = rounds[prevRound].answer;
        // We do not want the validator to ever prevent reporting, so we limit its
        // gas usage and catch any errors that may arise.
        try
            av.validate{gas: VALIDATOR_GAS_LIMIT}(
                prevAnswerRoundId,
                prevRoundAnswer,
                _roundId,
                _newAnswer
            )
        {} catch {}
    }

    function payOracle(uint32 _roundId) private {
        uint128 payment = details[_roundId].paymentAmount;
        Funds memory funds = recordedFunds;
        funds.available = funds.available.sub(payment);
        funds.allocated = funds.allocated.add(payment);
        recordedFunds = funds;
        oracles[msg.sender].withdrawable = oracles[msg.sender].withdrawable.add(
            payment
        );

        emit AvailableFundsUpdated(funds.available);
    }

    function recordSubmission(int256 _submission, uint32 _roundId) private {
        require(
            acceptingSubmissions(_roundId),
            "round not accepting submissions"
        );

        details[_roundId].submissions.push(_submission);
        oracles[msg.sender].lastReportedRound = _roundId;
        oracles[msg.sender].latestSubmission = _submission;

        emit SubmissionReceived(_submission, _roundId, msg.sender);
    }

    function deleteRoundDetails(uint32 _roundId) private {
        if (
            details[_roundId].submissions.length <
            details[_roundId].maxSubmissions
        ) return;

        delete details[_roundId];
    }

    function timedOut(uint32 _roundId) private view returns (bool) {
        uint64 startedAt = rounds[_roundId].startedAt;
        uint32 roundTimeout = details[_roundId].timeout;
        return
            startedAt > 0 &&
            roundTimeout > 0 &&
            startedAt.add(roundTimeout) < block.timestamp;
    }

    function getStartingRound(address _oracle) private view returns (uint32) {
        uint32 currentRound = reportingRoundId;
        if (currentRound != 0 && currentRound == oracles[_oracle].endingRound) {
            return currentRound;
        }
        return currentRound.add(1);
    }

    function previousAndCurrentUnanswered(uint32 _roundId, uint32 _rrId)
        private
        view
        returns (bool)
    {
        return _roundId.add(1) == _rrId && rounds[_rrId].updatedAt == 0;
    }

    function requiredReserve(uint256 payment) private view returns (uint256) {
        return payment.mul(oracleCount()).mul(RESERVE_ROUNDS);
    }

    function addOracle(address _oracle, address _admin) private {
        require(!oracleEnabled(_oracle), "oracle already enabled");

        require(_admin != address(0), "cannot set admin to 0");
        require(
            oracles[_oracle].admin == address(0) ||
                oracles[_oracle].admin == _admin,
            "owner cannot overwrite admin"
        );

        oracles[_oracle].startingRound = getStartingRound(_oracle);
        oracles[_oracle].endingRound = ROUND_MAX;
        oracles[_oracle].index = uint16(oracleAddresses.length);
        oracleAddresses.push(_oracle);
        oracles[_oracle].admin = _admin;

        emit OraclePermissionsUpdated(_oracle, true);
        emit OracleAdminUpdated(_oracle, _admin);
    }

    function removeOracle(address _oracle) private {
        require(oracleEnabled(_oracle), "oracle not enabled");

        oracles[_oracle].endingRound = reportingRoundId.add(1);
        address tail = oracleAddresses[uint256(oracleCount()).sub(1)];
        uint16 index = oracles[_oracle].index;
        oracles[tail].index = index;
        delete oracles[_oracle].index;
        oracleAddresses[index] = tail;
        oracleAddresses.pop();

        emit OraclePermissionsUpdated(_oracle, false);
    }

    function validateOracleRound(address _oracle, uint32 _roundId)
        private
        view
        returns (bytes memory)
    {
        // cache storage reads
        uint32 startingRound = oracles[_oracle].startingRound;
        uint32 rrId = reportingRoundId;

        if (startingRound == 0) return "not enabled oracle";
        if (startingRound > _roundId) return "not yet enabled oracle";
        if (oracles[_oracle].endingRound < _roundId)
            return "no longer allowed oracle";
        if (oracles[_oracle].lastReportedRound >= _roundId)
            return "cannot report on previous rounds";
        if (
            _roundId != rrId &&
            _roundId != rrId.add(1) &&
            !previousAndCurrentUnanswered(_roundId, rrId)
        ) return "invalid round to report";
        if (_roundId != 1 && !supersedable(_roundId.sub(1)))
            return "previous round not supersedable";
    }

    function supersedable(uint32 _roundId) private view returns (bool) {
        return rounds[_roundId].updatedAt > 0 || timedOut(_roundId);
    }

    function oracleEnabled(address _oracle) private view returns (bool) {
        return oracles[_oracle].endingRound == ROUND_MAX;
    }

    function acceptingSubmissions(uint32 _roundId) private view returns (bool) {
        return details[_roundId].maxSubmissions != 0;
    }

    function delayed(address _oracle, uint32 _roundId)
        private
        view
        returns (bool)
    {
        uint256 lastStarted = oracles[_oracle].lastStartedRound;
        return _roundId > lastStarted + restartDelay || lastStarted == 0;
    }

    function newRound(uint32 _roundId) private view returns (bool) {
        return _roundId == reportingRoundId.add(1);
    }

    function validRoundId(uint256 _roundId) private view returns (bool) {
        return _roundId <= ROUND_MAX;
    }
}

// File: contracts/oracle/IOracleAdapter.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

/**
 * @notice Interface for securely interacting with Chainlink aggregators
 */
interface IOracleAdapter {
    struct Value {
        uint256 value;
        uint256 periodEnd;
    }

    /// @notice Event fired when asset's pricing source (aggregator) is updated
    event AssetSourceUpdated(address indexed asset, address indexed source);

    /// @notice Event fired when the TVL aggregator address is updated
    event TvlSourceUpdated(address indexed source);

    /**
     * @notice Set the TVL source (aggregator)
     * @param source The new TVL source (aggregator)
     */
    function emergencySetTvlSource(address source) external;

    /**
     * @notice Set an asset's price source (aggregator)
     * @param asset The asset to change the source of
     * @param source The new source (aggregator)
     */
    function emergencySetAssetSource(address asset, address source) external;

    /**
     * @notice Set multiple assets' pricing sources
     * @param assets An array of assets (tokens)
     * @param sources An array of price sources (aggregators)
     */
    function emergencySetAssetSources(
        address[] memory assets,
        address[] memory sources
    ) external;

    /**
     * @notice Retrieve the asset's price from its pricing source
     * @param asset The asset address
     * @return The price of the asset
     */
    function getAssetPrice(address asset) external view returns (uint256);

    /**
     * @notice Retrieve the deployed TVL from the TVL aggregator
     * @return The TVL
     */
    function getTvl() external view returns (uint256);
}

// File: contracts/oracle/IOverrideOracle.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IOracleAdapter} from "./IOracleAdapter.sol";

interface IOverrideOracle is IOracleAdapter {
    /**
     * @notice Event fired when asset value is set manually
     * @param asset The asset that is being overridden
     * @param value The new value used for the override
     * @param period The number of blocks the override will be active for
     * @param periodEnd The block on which the override ends
     */
    event AssetValueSet(
        address asset,
        uint256 value,
        uint256 period,
        uint256 periodEnd
    );

    /**
     * @notice Event fired when manually submitted asset value is
     * invalidated, allowing usual Chainlink pricing.
     */
    event AssetValueUnset(address asset);

    /**
     * @notice Event fired when deployed TVL is set manually
     * @param value The new value used for the override
     * @param period The number of blocks the override will be active for
     * @param periodEnd The block on which the override ends
     */
    event TvlSet(uint256 value, uint256 period, uint256 periodEnd);

    /**
     * @notice Event fired when manually submitted TVL is
     * invalidated, allowing usual Chainlink pricing.
     */
    event TvlUnset();

    /**
     * @notice Manually override the asset pricing source with a value
     * @param asset The asset that is being overriden
     * @param value asset value to return instead of from Chainlink
     * @param period length of time, in number of blocks, to use manual override
     */
    function emergencySetAssetValue(
        address asset,
        uint256 value,
        uint256 period
    ) external;

    /**
     * @notice Revoke manually set value, allowing usual Chainlink pricing
     * @param asset address of asset to price
     */
    function emergencyUnsetAssetValue(address asset) external;

    /**
     * @notice Manually override the TVL source with a value
     * @param value TVL to return instead of from Chainlink
     * @param period length of time, in number of blocks, to use manual override
     */
    function emergencySetTvl(uint256 value, uint256 period) external;

    /// @notice Revoke manually set value, allowing usual Chainlink pricing
    function emergencyUnsetTvl() external;

    /// @notice Check if TVL has active manual override
    function hasTvlOverride() external view returns (bool);

    /**
     * @notice Check if asset has active manual override
     * @param asset address of the asset
     * @return `true` if manual override is active
     */
    function hasAssetOverride(address asset) external view returns (bool);
}

// File: contracts/oracle/ILockingOracle.sol



// SPDX-License-Identifier: BUSDL-1.1
pragma solidity 0.6.11;

import {IOracleAdapter} from "./IOracleAdapter.sol";

/**
 * @notice For an `IOracleAdapter` that can be locked and unlocked
 */
interface ILockingOracle is IOracleAdapter {
    /// @notice Event fired when using the default lock
    event DefaultLocked(address locker, uint256 defaultPeriod, uint256 lockEnd);

    /// @notice Event fired when using a specified lock period
    event Locked(address locker, uint256 activePeriod, uint256 lockEnd);

    /// @notice Event fired when changing the default locking period
    event DefaultLockPeriodChanged(uint256 newPeriod);

    /// @notice Event fired when unlocking the adapter
    event Unlocked();

    /// @notice Event fired when updating the threshold for stale data
    event ChainlinkStalePeriodUpdated(uint256 period);

    /// @notice Block price/value retrieval for the default locking duration
    function lock() external;

    /**
     * @notice Block price/value retrieval for the specified duration.
     * @param period number of blocks to block retrieving values
     */
    function lockFor(uint256 period) external;

    /**
     * @notice Unblock price/value retrieval.  Should only be callable
     * by the Emergency Safe.
     */
    function emergencyUnlock() external;

    /**
     * @notice Set the length of time before values can be retrieved.
     * @param newPeriod number of blocks before values can be retrieved
     */
    function setDefaultLockPeriod(uint256 newPeriod) external;

    /**
     * @notice Set the length of time before an agg value is considered stale.
     * @param chainlinkStalePeriod_ the length of time in seconds
     */
    function setChainlinkStalePeriod(uint256 chainlinkStalePeriod_) external;

    /**
     * @notice Get the length of time, in number of blocks, before values
     * can be retrieved.
     */
    function defaultLockPeriod() external returns (uint256 period);

    /// @notice Check if the adapter is blocked from retrieving values.
    function isLocked() external view returns (bool);
}

// File: @chainlink/contracts/src/v0.6/Median.sol



pragma solidity ^0.6.0;

import "./vendor/SafeMath.sol";
import "./SignedSafeMath.sol";

library Median {
  using SignedSafeMath for int256;

  int256 constant INT_MAX = 2**255-1;

  /**
   * @notice Returns the sorted middle, or the average of the two middle indexed items if the
   * array has an even number of elements.
   * @dev The list passed as an argument isn't modified.
   * @dev This algorithm has expected runtime O(n), but for adversarially chosen inputs
   * the runtime is O(n^2).
   * @param list The list of elements to compare
   */
  function calculate(int256[] memory list)
    internal
    pure
    returns (int256)
  {
    return calculateInplace(copy(list));
  }

  /**
   * @notice See documentation for function calculate.
   * @dev The list passed as an argument may be permuted.
   */
  function calculateInplace(int256[] memory list)
    internal
    pure
    returns (int256)
  {
    require(0 < list.length, "list must not be empty");
    uint256 len = list.length;
    uint256 middleIndex = len / 2;
    if (len % 2 == 0) {
      int256 median1;
      int256 median2;
      (median1, median2) = quickselectTwo(list, 0, len - 1, middleIndex - 1, middleIndex);
      return SignedSafeMath.avg(median1, median2);
    } else {
      return quickselect(list, 0, len - 1, middleIndex);
    }
  }

  /**
   * @notice Maximum length of list that shortSelectTwo can handle
   */
  uint256 constant SHORTSELECTTWO_MAX_LENGTH = 7;

  /**
   * @notice Select the k1-th and k2-th element from list of length at most 7
   * @dev Uses an optimal sorting network
   */
  function shortSelectTwo(
    int256[] memory list,
    uint256 lo,
    uint256 hi,
    uint256 k1,
    uint256 k2
  )
    private
    pure
    returns (int256 k1th, int256 k2th)
  {
    // Uses an optimal sorting network (https://en.wikipedia.org/wiki/Sorting_network)
    // for lists of length 7. Network layout is taken from
    // http://jgamble.ripco.net/cgi-bin/nw.cgi?inputs=7&algorithm=hibbard&output=svg

    uint256 len = hi + 1 - lo;
    int256 x0 = list[lo + 0];
    int256 x1 = 1 < len ? list[lo + 1] : INT_MAX;
    int256 x2 = 2 < len ? list[lo + 2] : INT_MAX;
    int256 x3 = 3 < len ? list[lo + 3] : INT_MAX;
    int256 x4 = 4 < len ? list[lo + 4] : INT_MAX;
    int256 x5 = 5 < len ? list[lo + 5] : INT_MAX;
    int256 x6 = 6 < len ? list[lo + 6] : INT_MAX;

    if (x0 > x1) {(x0, x1) = (x1, x0);}
    if (x2 > x3) {(x2, x3) = (x3, x2);}
    if (x4 > x5) {(x4, x5) = (x5, x4);}
    if (x0 > x2) {(x0, x2) = (x2, x0);}
    if (x1 > x3) {(x1, x3) = (x3, x1);}
    if (x4 > x6) {(x4, x6) = (x6, x4);}
    if (x1 > x2) {(x1, x2) = (x2, x1);}
    if (x5 > x6) {(x5, x6) = (x6, x5);}
    if (x0 > x4) {(x0, x4) = (x4, x0);}
    if (x1 > x5) {(x1, x5) = (x5, x1);}
    if (x2 > x6) {(x2, x6) = (x6, x2);}
    if (x1 > x4) {(x1, x4) = (x4, x1);}
    if (x3 > x6) {(x3, x6) = (x6, x3);}
    if (x2 > x4) {(x2, x4) = (x4, x2);}
    if (x3 > x5) {(x3, x5) = (x5, x3);}
    if (x3 > x4) {(x3, x4) = (x4, x3);}

    uint256 index1 = k1 - lo;
    if (index1 == 0) {k1th = x0;}
    else if (index1 == 1) {k1th = x1;}
    else if (index1 == 2) {k1th = x2;}
    else if (index1 == 3) {k1th = x3;}
    else if (index1 == 4) {k1th = x4;}
    else if (index1 == 5) {k1th = x5;}
    else if (index1 == 6) {k1th = x6;}
    else {revert("k1 out of bounds");}

    uint256 index2 = k2 - lo;
    if (k1 == k2) {return (k1th, k1th);}
    else if (index2 == 0) {return (k1th, x0);}
    else if (index2 == 1) {return (k1th, x1);}
    else if (index2 == 2) {return (k1th, x2);}
    else if (index2 == 3) {return (k1th, x3);}
    else if (index2 == 4) {return (k1th, x4);}
    else if (index2 == 5) {return (k1th, x5);}
    else if (index2 == 6) {return (k1th, x6);}
    else {revert("k2 out of bounds");}
  }

  /**
   * @notice Selects the k-th ranked element from list, looking only at indices between lo and hi
   * (inclusive). Modifies list in-place.
   */
  function quickselect(int256[] memory list, uint256 lo, uint256 hi, uint256 k)
    private
    pure
    returns (int256 kth)
  {
    require(lo <= k);
    require(k <= hi);
    while (lo < hi) {
      if (hi - lo < SHORTSELECTTWO_MAX_LENGTH) {
        int256 ignore;
        (kth, ignore) = shortSelectTwo(list, lo, hi, k, k);
        return kth;
      }
      uint256 pivotIndex = partition(list, lo, hi);
      if (k <= pivotIndex) {
        // since pivotIndex < (original hi passed to partition),
        // termination is guaranteed in this case
        hi = pivotIndex;
      } else {
        // since (original lo passed to partition) <= pivotIndex,
        // termination is guaranteed in this case
        lo = pivotIndex + 1;
      }
    }
    return list[lo];
  }

  /**
   * @notice Selects the k1-th and k2-th ranked elements from list, looking only at indices between
   * lo and hi (inclusive). Modifies list in-place.
   */
  function quickselectTwo(
    int256[] memory list,
    uint256 lo,
    uint256 hi,
    uint256 k1,
    uint256 k2
  )
    internal // for testing
    pure
    returns (int256 k1th, int256 k2th)
  {
    require(k1 < k2);
    require(lo <= k1 && k1 <= hi);
    require(lo <= k2 && k2 <= hi);

    while (true) {
      if (hi - lo < SHORTSELECTTWO_MAX_LENGTH) {
        return shortSelectTwo(list, lo, hi, k1, k2);
      }
      uint256 pivotIdx = partition(list, lo, hi);
      if (k2 <= pivotIdx) {
        hi = pivotIdx;
      } else if (pivotIdx < k1) {
        lo = pivotIdx + 1;
      } else {
        assert(k1 <= pivotIdx && pivotIdx < k2);
        k1th = quickselect(list, lo, pivotIdx, k1);
        k2th = quickselect(list, pivotIdx + 1, hi, k2);
        return (k1th, k2th);
      }
    }
  }

  /**
   * @notice Partitions list in-place using Hoare's partitioning scheme.
   * Only elements of list between indices lo and hi (inclusive) will be modified.
   * Returns an index i, such that:
   * - lo <= i < hi
   * - forall j in [lo, i]. list[j] <= list[i]
   * - forall j in [i, hi]. list[i] <= list[j]
   */
  function partition(int256[] memory list, uint256 lo, uint256 hi)
    private
    pure
    returns (uint256)
  {
    // We don't care about overflow of the addition, because it would require a list
    // larger than any feasible computer's memory.
    int256 pivot = list[(lo + hi) / 2];
    lo -= 1; // this can underflow. that's intentional.
    hi += 1;
    while (true) {
      do {
        lo += 1;
      } while (list[lo] < pivot);
      do {
        hi -= 1;
      } while (list[hi] > pivot);
      if (lo < hi) {
        (list[lo], list[hi]) = (list[hi], list[lo]);
      } else {
        // Let orig_lo and orig_hi be the original values of lo and hi passed to partition.
        // Then, hi < orig_hi, because hi decreases *strictly* monotonically
        // in each loop iteration and
        // - either list[orig_hi] > pivot, in which case the first loop iteration
        //   will achieve hi < orig_hi;
        // - or list[orig_hi] <= pivot, in which case at least two loop iterations are
        //   needed:
        //   - lo will have to stop at least once in the interval
        //     [orig_lo, (orig_lo + orig_hi)/2]
        //   - (orig_lo + orig_hi)/2 < orig_hi
        return hi;
      }
    }
  }

  /**
   * @notice Makes an in-memory copy of the array passed in
   * @param list Reference to the array to be copied
   */
  function copy(int256[] memory list)
    private
    pure
    returns(int256[] memory)
  {
    int256[] memory list2 = new int256[](list.length);
    for (uint256 i = 0; i < list.length; i++) {
      list2[i] = list[i];
    }
    return list2;
  }
}

// File: @chainlink/contracts/src/v0.6/Owned.sol



pragma solidity ^0.6.0;

/**
 * @title The Owned contract
 * @notice A contract with helpers for basic contract ownership.
 */
contract Owned {

  address payable public owner;
  address private pendingOwner;

  event OwnershipTransferRequested(
    address indexed from,
    address indexed to
  );
  event OwnershipTransferred(
    address indexed from,
    address indexed to
  );

  constructor() public {
    owner = msg.sender;
  }

  /**
   * @dev Allows an owner to begin transferring ownership to a new address,
   * pending.
   */
  function transferOwnership(address _to)
    external
    onlyOwner()
  {
    pendingOwner = _to;

    emit OwnershipTransferRequested(owner, _to);
  }

  /**
   * @dev Allows an ownership transfer to be completed by the recipient.
   */
  function acceptOwnership()
    external
  {
    require(msg.sender == pendingOwner, "Must be proposed owner");

    address oldOwner = owner;
    owner = msg.sender;
    pendingOwner = address(0);

    emit OwnershipTransferred(oldOwner, msg.sender);
  }

  /**
   * @dev Reverts if called by anyone other than the contract owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner, "Only callable by owner");
    _;
  }

}

// File: @chainlink/contracts/src/v0.6/SafeMath128.sol



pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * This library is a version of Open Zeppelin's SafeMath, modified to support
 * unsigned 128 bit integers.
 */
library SafeMath128 {
  /**
    * @dev Returns the addition of two unsigned integers, reverting on
    * overflow.
    *
    * Counterpart to Solidity's `+` operator.
    *
    * Requirements:
    * - Addition cannot overflow.
    */
  function add(uint128 a, uint128 b) internal pure returns (uint128) {
    uint128 c = a + b;
    require(c >= a, "SafeMath: addition overflow");

    return c;
  }

  /**
    * @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(uint128 a, uint128 b) internal pure returns (uint128) {
    require(b <= a, "SafeMath: subtraction overflow");
    uint128 c = a - b;

    return c;
  }

  /**
    * @dev Returns the multiplication of two unsigned integers, reverting on
    * overflow.
    *
    * Counterpart to Solidity's `*` operator.
    *
    * Requirements:
    * - Multiplication cannot overflow.
    */
  function mul(uint128 a, uint128 b) internal pure returns (uint128) {
    // 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-solidity/pull/522
    if (a == 0) {
      return 0;
    }

    uint128 c = a * b;
    require(c / a == b, "SafeMath: multiplication overflow");

    return c;
  }

  /**
    * @dev Returns the integer division of two unsigned integers. Reverts 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(uint128 a, uint128 b) internal pure returns (uint128) {
    // Solidity only automatically asserts when dividing by 0
    require(b > 0, "SafeMath: division by zero");
    uint128 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
    * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
    * Reverts 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(uint128 a, uint128 b) internal pure returns (uint128) {
    require(b != 0, "SafeMath: modulo by zero");
    return a % b;
  }
}

// File: @chainlink/contracts/src/v0.6/SafeMath32.sol



pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * This library is a version of Open Zeppelin's SafeMath, modified to support
 * unsigned 32 bit integers.
 */
library SafeMath32 {
  /**
    * @dev Returns the addition of two unsigned integers, reverting on
    * overflow.
    *
    * Counterpart to Solidity's `+` operator.
    *
    * Requirements:
    * - Addition cannot overflow.
    */
  function add(uint32 a, uint32 b) internal pure returns (uint32) {
    uint32 c = a + b;
    require(c >= a, "SafeMath: addition overflow");

    return c;
  }

  /**
    * @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(uint32 a, uint32 b) internal pure returns (uint32) {
    require(b <= a, "SafeMath: subtraction overflow");
    uint32 c = a - b;

    return c;
  }

  /**
    * @dev Returns the multiplication of two unsigned integers, reverting on
    * overflow.
    *
    * Counterpart to Solidity's `*` operator.
    *
    * Requirements:
    * - Multiplication cannot overflow.
    */
  function mul(uint32 a, uint32 b) internal pure returns (uint32) {
    // 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-solidity/pull/522
    if (a == 0) {
      return 0;
    }

    uint32 c = a * b;
    require(c / a == b, "SafeMath: multiplication overflow");

    return c;
  }

  /**
    * @dev Returns the integer division of two unsigned integers. Reverts 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(uint32 a, uint32 b) internal pure returns (uint32) {
    // Solidity only automatically asserts when dividing by 0
    require(b > 0, "SafeMath: division by zero");
    uint32 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
    * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
    * Reverts 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(uint32 a, uint32 b) internal pure returns (uint32) {
    require(b != 0, "SafeMath: modulo by zero");
    return a % b;
  }
}

// File: @chainlink/contracts/src/v0.6/SafeMath64.sol



pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * This library is a version of Open Zeppelin's SafeMath, modified to support
 * unsigned 64 bit integers.
 */
library SafeMath64 {
  /**
    * @dev Returns the addition of two unsigned integers, reverting on
    * overflow.
    *
    * Counterpart to Solidity's `+` operator.
    *
    * Requirements:
    * - Addition cannot overflow.
    */
  function add(uint64 a, uint64 b) internal pure returns (uint64) {
    uint64 c = a + b;
    require(c >= a, "SafeMath: addition overflow");

    return c;
  }

  /**
    * @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(uint64 a, uint64 b) internal pure returns (uint64) {
    require(b <= a, "SafeMath: subtraction overflow");
    uint64 c = a - b;

    return c;
  }

  /**
    * @dev Returns the multiplication of two unsigned integers, reverting on
    * overflow.
    *
    * Counterpart to Solidity's `*` operator.
    *
    * Requirements:
    * - Multiplication cannot overflow.
    */
  function mul(uint64 a, uint64 b) internal pure returns (uint64) {
    // 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-solidity/pull/522
    if (a == 0) {
      return 0;
    }

    uint64 c = a * b;
    require(c / a == b, "SafeMath: multiplication overflow");

    return c;
  }

  /**
    * @dev Returns the integer division of two unsigned integers. Reverts 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(uint64 a, uint64 b) internal pure returns (uint64) {
    // Solidity only automatically asserts when dividing by 0
    require(b > 0, "SafeMath: division by zero");
    uint64 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
    * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
    * Reverts 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(uint64 a, uint64 b) internal pure returns (uint64) {
    require(b != 0, "SafeMath: modulo by zero");
    return a % b;
  }
}

// File: @chainlink/contracts/src/v0.6/interfaces/AggregatorV2V3Interface.sol



pragma solidity >=0.6.0;

import "./AggregatorInterface.sol";
import "./AggregatorV3Interface.sol";

interface AggregatorV2V3Interface is AggregatorInterface, AggregatorV3Interface
{
}

// File: @chainlink/contracts/src/v0.6/interfaces/AggregatorValidatorInterface.sol



pragma solidity ^0.6.0;

interface AggregatorValidatorInterface {
  function validate(
    uint256 previousRoundId,
    int256 previousAnswer,
    uint256 currentRoundId,
    int256 currentAnswer
  ) external returns (bool);
}

// File: @chainlink/contracts/src/v0.6/interfaces/LinkTokenInterface.sol



pragma solidity ^0.6.0;

interface LinkTokenInterface {
  function allowance(address owner, address spender) external view returns (uint256 remaining);
  function approve(address spender, uint256 value) external returns (bool success);
  function balanceOf(address owner) external view returns (uint256 balance);
  function decimals() external view returns (uint8 decimalPlaces);
  function decreaseApproval(address spender, uint256 addedValue) external returns (bool success);
  function increaseApproval(address spender, uint256 subtractedValue) external;
  function name() external view returns (string memory tokenName);
  function symbol() external view returns (string memory tokenSymbol);
  function totalSupply() external view returns (uint256 totalTokensIssued);
  function transfer(address to, uint256 value) external returns (bool success);
  function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool success);
  function transferFrom(address from, address to, uint256 value) external returns (bool success);
}

// File: @chainlink/contracts/src/v0.6/vendor/SafeMath.sol



pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
  /**
    * @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) {
    uint256 c = a + b;
    require(c >= a, "SafeMath: addition overflow");

    return c;
  }

  /**
    * @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) {
    require(b <= a, "SafeMath: subtraction overflow");
    uint256 c = a - b;

    return c;
  }

  /**
    * @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) {
    // 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-solidity/pull/522
    if (a == 0) {
      return 0;
    }

    uint256 c = a * b;
    require(c / a == b, "SafeMath: multiplication overflow");

    return c;
  }

  /**
    * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
    // Solidity only automatically asserts when dividing by 0
    require(b > 0, "SafeMath: division by zero");
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
    * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
    * Reverts 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) {
    require(b != 0, "SafeMath: modulo by zero");
    return a % b;
  }
}

// File: @chainlink/contracts/src/v0.6/SignedSafeMath.sol



pragma solidity ^0.6.0;

library SignedSafeMath {
  int256 constant private _INT256_MIN = -2**255;

  /**
   * @dev Multiplies two signed integers, reverts on overflow.
   */
  function mul(int256 a, int256 b) internal pure returns (int256) {
    // 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 0;
    }

    require(!(a == -1 && b == _INT256_MIN), "SignedSafeMath: multiplication overflow");

    int256 c = a * b;
    require(c / a == b, "SignedSafeMath: multiplication overflow");

    return c;
  }

  /**
   * @dev Integer division of two signed integers truncating the quotient, reverts on division by zero.
   */
  function div(int256 a, int256 b) internal pure returns (int256) {
    require(b != 0, "SignedSafeMath: division by zero");
    require(!(b == -1 && a == _INT256_MIN), "SignedSafeMath: division overflow");

    int256 c = a / b;

    return c;
  }

  /**
   * @dev Subtracts two signed integers, reverts on overflow.
   */
  function sub(int256 a, int256 b) internal pure returns (int256) {
    int256 c = a - b;
    require((b >= 0 && c <= a) || (b < 0 && c > a), "SignedSafeMath: subtraction overflow");

    return c;
  }

  /**
   * @dev Adds two signed integers, reverts on overflow.
   */
  function add(int256 a, int256 b) internal pure returns (int256) {
    int256 c = a + b;
    require((b >= 0 && c >= a) || (b < 0 && c < a), "SignedSafeMath: addition overflow");

    return c;
  }

  /**
   * @notice Computes average of two signed integers, ensuring that the computation
   * doesn't overflow.
   * @dev If the result is not an integer, it is rounded towards zero. For example,
   * avg(-3, -4) = -3
   */
  function avg(int256 _a, int256 _b)
    internal
    pure
    returns (int256)
  {
    if ((_a < 0 && _b > 0) || (_a > 0 && _b < 0)) {
      return add(_a, _b) / 2;
    }
    int256 remainder = (_a % 2 + _b % 2) / 2;
    return add(add(_a / 2, _b / 2), remainder);
  }
}

// File: @chainlink/contracts/src/v0.6/interfaces/AggregatorInterface.sol



pragma solidity >=0.6.0;

interface AggregatorInterface {
  function latestAnswer() external view returns (int256);
  function latestTimestamp() external view returns (uint256);
  function latestRound() external view returns (uint256);
  function getAnswer(uint256 roundId) external view returns (int256);
  function getTimestamp(uint256 roundId) external view returns (uint256);

  event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 updatedAt);
  event NewRound(uint256 indexed roundId, address indexed startedBy, uint256 startedAt);
}

// File: @chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol



pragma solidity >=0.6.0;

interface AggregatorV3Interface {

  function decimals() external view returns (uint8);
  function description() external view returns (string memory);
  function version() external view returns (uint256);

  // getRoundData and latestRoundData should both raise "No data present"
  // if they do not have data to report, instead of returning unset values
  // which could be misinterpreted as actual reported values.
  function getRoundData(uint80 _roundId)
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );
  function latestRoundData()
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

}