// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IArbitrumFeeProvider.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

interface IArbitrumFeeProvider {
    function getArbitrumFees()
        external
        view
        returns (
            uint256 gasLimit,
            uint256 gasPrice,
            uint256 maxSubmissionCost
        );

    function setArbitrumFees(
        uint64 gasLimit,
        uint64 gasPrice,
        uint64 maxSubmissionCost
    ) external;
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IAuthorizerAdaptor.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "../solidity-utils/helpers/IAuthentication.sol";
import "../vault/IVault.sol";

interface IAuthorizerAdaptor is IAuthentication {
    /**
     * @notice Returns the Balancer Vault
     */
    function getVault() external view returns (IVault);

    /**
     * @notice Returns the Authorizer
     */
    function getAuthorizer() external view returns (IAuthorizer);

    /**
     * @notice Performs an arbitrary function call on a target contract, provided the caller is authorized to do so.
     * @param target - Address of the contract to be called
     * @param data - Calldata to be sent to the target contract
     * @return The bytes encoded return value from the performed function call
     */
    function performAction(address target, bytes calldata data) external payable returns (bytes memory);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IAuthorizerAdaptorEntrypoint.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "./IAuthorizerAdaptor.sol";

/**
 * @notice Interface for `AuthorizerAdaptorEntrypoint`.
 */
interface IAuthorizerAdaptorEntrypoint is IAuthorizerAdaptor {
    /**
     * @notice Returns the Authorizer Adaptor
     */
    function getAuthorizerAdaptor() external view returns (IAuthorizerAdaptor);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IBalancerMinter.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "../solidity-utils/openzeppelin/IERC20.sol";

/**
 * @dev Base minter interface, applicable to Mainnet minter or L2 pseudo minters.
 */
interface IBalancerMinter {
    event Minted(address indexed recipient, address gauge, uint256 minted);

    /**
     * @notice Returns the address of the Balancer Governance Token
     */
    function getBalancerToken() external view returns (IERC20);

    /**
     * @notice Mint everything which belongs to `msg.sender` and send to them
     * @param gauge `LiquidityGauge` address to get mintable amount from
     */
    function mint(address gauge) external returns (uint256);

    /**
     * @notice Mint everything which belongs to `msg.sender` across multiple gauges
     * @param gauges List of `LiquidityGauge` addresses
     */
    function mintMany(address[] calldata gauges) external returns (uint256);

    /**
     * @notice Mint tokens for `user`
     * @dev Only possible when `msg.sender` has been approved by `user` to mint on their behalf
     * @param gauge `LiquidityGauge` address to get mintable amount from
     * @param user Address to mint to
     */
    function mintFor(address gauge, address user) external returns (uint256);

    /**
     * @notice Mint tokens for `user` across multiple gauges
     * @dev Only possible when `msg.sender` has been approved by `user` to mint on their behalf
     * @param gauges List of `LiquidityGauge` addresses
     * @param user Address to mint to
     */
    function mintManyFor(address[] calldata gauges, address user) external returns (uint256);

    /**
     * @notice The total number of tokens minted for `user` from `gauge`
     */
    function minted(address user, address gauge) external view returns (uint256);

    /**
     * @notice Whether `minter` is approved to mint tokens for `user`
     */
    function getMinterApproval(address minter, address user) external view returns (bool);

    /**
     * @notice Set whether `minter` is approved to mint tokens on your behalf
     */
    function setMinterApproval(address minter, bool approval) external;

    /**
     * @notice Set whether `minter` is approved to mint tokens on behalf of `user`, who has signed a message authorizing
     * them.
     */
    function setMinterApprovalWithSignature(
        address minter,
        bool approval,
        address user,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    // The below functions are near-duplicates of functions available above.
    // They are included for ABI compatibility with snake_casing as used in vyper contracts.
    // solhint-disable func-name-mixedcase

    /**
     * @notice Whether `minter` is approved to mint tokens for `user`
     */
    function allowed_to_mint_for(address minter, address user) external view returns (bool);

    /**
     * @notice Mint everything which belongs to `msg.sender` across multiple gauges
     * @dev This function is not recommended as `mintMany()` is more flexible and gas efficient
     * @param gauges List of `LiquidityGauge` addresses
     */
    function mint_many(address[8] calldata gauges) external;

    /**
     * @notice Mint tokens for `user`
     * @dev Only possible when `msg.sender` has been approved by `user` to mint on their behalf
     * @param gauge `LiquidityGauge` address to get mintable amount from
     * @param user Address to mint to
     */
    function mint_for(address gauge, address user) external;

    /**
     * @notice Toggle whether `minter` is approved to mint tokens for `user`
     */
    function toggle_approve_mint(address minter) external;
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IBalancerToken.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "../solidity-utils/openzeppelin/IERC20.sol";

interface IBalancerToken is IERC20 {
    function mint(address to, uint256 amount) external;

    function getRoleMemberCount(bytes32 role) external view returns (uint256);

    function getRoleMember(bytes32 role, uint256 index) external view returns (address);

    function hasRole(bytes32 role, address account) external view returns (bool);

    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    function grantRole(bytes32 role, address account) external;

    function revokeRole(bytes32 role, address account) external;

    // solhint-disable-next-line func-name-mixedcase
    function DEFAULT_ADMIN_ROLE() external view returns (bytes32);

    // solhint-disable-next-line func-name-mixedcase
    function MINTER_ROLE() external view returns (bytes32);

    // solhint-disable-next-line func-name-mixedcase
    function SNAPSHOT_ROLE() external view returns (bytes32);

    function snapshot() external;
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IBalancerTokenAdmin.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "../solidity-utils/helpers/IAuthentication.sol";

import "./IBalancerToken.sol";

interface IBalancerTokenAdmin is IAuthentication {
    // solhint-disable func-name-mixedcase
    function INITIAL_RATE() external view returns (uint256);

    function RATE_REDUCTION_TIME() external view returns (uint256);

    function RATE_REDUCTION_COEFFICIENT() external view returns (uint256);

    function RATE_DENOMINATOR() external view returns (uint256);

    // solhint-enable func-name-mixedcase

    /**
     * @notice Returns the address of the Balancer Governance Token
     */
    function getBalancerToken() external view returns (IBalancerToken);

    function activate() external;

    function rate() external view returns (uint256);

    function startEpochTimeWrite() external returns (uint256);

    function mint(address to, uint256 amount) external;
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IGaugeAdder.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;
pragma experimental ABIEncoderV2;

import "./IAuthorizerAdaptorEntrypoint.sol";
import "./IGaugeController.sol";
import "./ILiquidityGauge.sol";
import "./ILiquidityGaugeFactory.sol";
import "./IStakingLiquidityGauge.sol";

interface IGaugeAdder is IAuthentication {
    // Deprecated. TODO: remove from interfaces, and remove references.
    enum GaugeType { LiquidityMiningCommittee, veBAL, Ethereum, Polygon, Arbitrum, Optimism, Gnosis, ZKSync }

    // String values are hashed when indexed, so we also emit the raw string as a data field for ease of use.
    event GaugeTypeAdded(string indexed indexedGaugeType, string gaugeType);
    event GaugeFactorySet(string indexed indexedGaugeType, string gaugeType, ILiquidityGaugeFactory gaugeFactory);

    /**
     * @notice Returns the address of the Authorizer adaptor entrypoint contract.
     */
    function getAuthorizerAdaptorEntrypoint() external view returns (IAuthorizerAdaptorEntrypoint);

    /**
     * @notice Returns the address of the Gauge Controller
     */
    function getGaugeController() external view returns (IGaugeController);

    /**
     * @notice Returns the list of gauge types.
     */
    function getGaugeTypes() external view returns (string[] memory);

    /**
     * @notice Returns gauge type name registered at the given index.
     */
    function getGaugeTypeAtIndex(uint256 index) external view returns (string memory);

    /**
     * @notice Returns the number of gauge types.
     */
    function getGaugeTypesCount() external view returns (uint256);

    /**
     * @notice Returns true if the given gauge type is valid; false otherwise.
     */
    function isValidGaugeType(string memory gaugeType) external view returns (bool);

    /**
     * @notice Returns the factory for gauge type `gaugeType`.
     */
    function getFactoryForGaugeType(string memory gaugeType) external view returns (ILiquidityGaugeFactory);

    /**
     * @notice Returns true if `gauge` has been deployed by the factory for the gauge type `gaugeType`.
     * Note that if a gauge type's factory changes then this function will start returning false for previously
     * valid gauges.
     */
    function isGaugeFromValidFactory(address gauge, string memory gaugeType) external view returns (bool);

    /**
     * @notice Adds a new `gaugeType` corresponding to a new network, which allows setting a factory and adding gauges
     * for the type later on.
     * @param gaugeType Name of the new gauge type.
     */
    function addGaugeType(string memory gaugeType) external;

    /**
     * @notice Adds a new gauge to the GaugeController for the given `gaugeType` type.
     * @dev When adding gauges for L2 networks or sidechains, this must be called with the address of the *root* gauge
     * which is deployed on Ethereum. It should *not* be called with the address of the child gauge which is deployed on
     * the L2 / sidechain.
     *
     * If the gauge added is an Ethereum gauge, it cannot be a gauge for the 80BAL-20WETH pool.
     */
    function addGauge(address gauge, string memory gaugeType) external;

    /**
     * @notice Sets `factory` as the allowlisted factory contract for gauges with type `gaugeType`.
     * @dev This function can either set a new factory or replace an existing one.
     */
    function setGaugeFactory(ILiquidityGaugeFactory factory, string memory gaugeType) external;
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IGaugeController.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "../solidity-utils/openzeppelin/IERC20.sol";

import "./IAuthorizerAdaptor.sol";
import "./IVotingEscrow.sol";

// For compatibility, we're keeping the same function names as in the original Curve code, including the mixed-case
// naming convention.
// solhint-disable func-name-mixedcase

interface IGaugeController {
    function checkpoint_gauge(address gauge) external;

    function gauge_relative_weight(address gauge, uint256 time) external view returns (uint256);

    function voting_escrow() external view returns (IVotingEscrow);

    function token() external view returns (IERC20);

    function add_type(string calldata name, uint256 weight) external;

    function change_type_weight(int128 typeId, uint256 weight) external;

    function add_gauge(address gauge, int128 gaugeType) external;

    function n_gauge_types() external view returns (int128);

    function gauge_types(address gauge) external view returns (int128);

    function admin() external view returns (IAuthorizerAdaptor);

    function gauge_exists(address gauge) external view returns (bool);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IL2GaugeCheckpointer.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;

import "./IGaugeAdder.sol";
import "./IStakelessGauge.sol";

/**
 * @title L2 Gauge Checkpointer interface
 * @notice Manages checkpoints for L2 and mainnet stakeless root gauges, allowing to perform mutiple checkpoints in a
 * single call.
 * @dev Supports gauge types registered in `GaugeAdder`.
 * Gauges to be checkpointed need to be added to the controller beforehand.
 */
interface IL2GaugeCheckpointer {
    // String values are hashed when indexed, so we also emit the raw string as a data field for ease of use.
    /**
     * @notice Emitted when a gauge is added to the checkpointer.
     */
    event GaugeAdded(IStakelessGauge indexed gauge, string indexed indexedGaugeType, string gaugeType);

    /**
     * @notice Emitted when a gauge is removed from the checkpointer.
     */
    event GaugeRemoved(IStakelessGauge indexed gauge, string indexed indexedGaugeType, string gaugeType);

    /**
     * @notice Returns `GaugeAdder` contract.
     */
    function getGaugeAdder() external view returns (IGaugeAdder);

    /**
     * @notice Adds an array of gauges from the given type. This is a permissioned function.
     * @dev Gauges added will be considered when performing checkpoints.
     * The gauges to add should meet the following preconditions:
     * - They must exist in the GaugeController, according to GaugeController#gauge_exists.
     * - They must not be killed.
     * - They must not have been previously added to the checkpointer.
     * Unlike `addGauges`, this function can add gauges that were created by factories registered in a deprecated
     * `GaugeAdder`, and therefore cannot be validated by the current `GaugeAdder`.
     * @param gaugeType Type of the gauge.
     * @param gauges Gauges to add.
     */
    function addGaugesWithVerifiedType(string memory gaugeType, IStakelessGauge[] calldata gauges) external;

    /**
     * @notice Adds an array of gauges from the given type.
     * @dev Gauges added will be considered when performing checkpoints.
     * The gauges to add should meet the following preconditions:
     * - They must have been created in a valid `GaugeFactory`, according to `GaugeAdder#isGaugeFromValidFactory`.
     * - They must exist in the `GaugeController`, according to `GaugeController#gauge_exists`.
     * - They must not be killed.
     * - They must not have been previously added to the checkpointer.
     * @param gaugeType Type of the gauge.
     * @param gauges Gauges to add.
     */
    function addGauges(string memory gaugeType, IStakelessGauge[] calldata gauges) external;

    /**
     * @notice Removes an array of gauges from the given type.
     * @dev Removed gauges will not be considered when performing checkpoints. To remove gauges:
     * - They must be killed.
     * - They must have been previously added to the checkpointer.
     * @param gaugeType Type of the gauge.
     * @param gauges Gauges to remove.
     */
    function removeGauges(string memory gaugeType, IStakelessGauge[] calldata gauges) external;

    /**
     * @notice Returns true if the given gauge was added for the given type; false otherwise.
     * @param gaugeType Type of the gauge.
     * @param gauge Gauge to check.
     */
    function hasGauge(string memory gaugeType, IStakelessGauge gauge) external view returns (bool);

    /**
     * @notice Returns the amount of added gauges for a given type.
     * @param gaugeType Type of the gauge.
     */
    function getTotalGauges(string memory gaugeType) external view returns (uint256);

    /**
     * @notice Returns the gauge of a given type at the given index.
     * @dev Reverts if the index is greater than or equal to the amount of added gauges for the given type.
     * @param gaugeType Type of the gauge.
     * @param index - Index of the added gauge.
     */
    function getGaugeAtIndex(string memory gaugeType, uint256 index) external view returns (IStakelessGauge);

    /**
     * @notice Performs a checkpoint for all added gauges above the given relative weight threshold.
     * @dev Reverts if the ETH sent in the call is not enough to cover bridge costs.
     * @param minRelativeWeight Threshold to filter out gauges below it.
     */
    function checkpointGaugesAboveRelativeWeight(uint256 minRelativeWeight) external payable;

    /**
     * @notice Performs a checkpoint for all added gauges of a given type above the given relative weight threshold.
     * @dev Reverts if the ETH sent in the call is not enough to cover bridge costs.
     * @param gaugeType Type of the gauge.
     * @param minRelativeWeight Threshold to filter out gauges below it.
     */
    function checkpointGaugesOfTypeAboveRelativeWeight(string memory gaugeType, uint256 minRelativeWeight)
        external
        payable;

    /**
     * @notice Performs a checkpoint for a single added gauge of a given type.
     * Reverts if the ETH sent in the call is not enough to cover bridge costs.
     * Reverts if the gauge was not added to the checkpointer beforehand.
     * @param gaugeType Type of the gauge.
     * @param gauge Address of the gauge to checkpoint.
     */
    function checkpointSingleGauge(string memory gaugeType, address gauge) external payable;

    /**
     * @notice Returns the ETH cost to checkpoint a single given gauge.
     * @dev Reverts if the gauge was not added to the checkpointer beforehand.
     * @param gaugeType Type of the gauge.
     * @param gauge Address of the gauge to check the bridge costs.
     */
    function getSingleBridgeCost(string memory gaugeType, address gauge) external view returns (uint256);

    /**
     * @notice Returns the ETH cost to checkpoint all gauges for a given minimum relative weight.
     * @dev A lower minimum relative weight might return higher costs, since more gauges could potentially be included
     * in the checkpoint.
     */
    function getTotalBridgeCost(uint256 minRelativeWeight) external view returns (uint256);

    /**
     * @notice Returns true if gauge type is valid; false otherwise.
     */
    function isValidGaugeType(string memory gaugeType) external view returns (bool);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/ILiquidityGauge.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

// For compatibility, we're keeping the same function names as in the original Curve code, including the mixed-case
// naming convention.
// solhint-disable func-name-mixedcase
// solhint-disable func-param-name-mixedcase

interface ILiquidityGauge {
    // solhint-disable-next-line var-name-mixedcase
    event RelativeWeightCapChanged(uint256 new_relative_weight_cap);

    /**
     * @notice Returns BAL liquidity emissions calculated during checkpoints for the given user.
     * @param user User address.
     * @return uint256 BAL amount to issue for the address.
     */
    function integrate_fraction(address user) external view returns (uint256);

    /**
     * @notice Record a checkpoint for a given user.
     * @param user User address.
     * @return bool Always true.
     */
    function user_checkpoint(address user) external returns (bool);

    /**
     * @notice Returns true if gauge is killed; false otherwise.
     */
    function is_killed() external view returns (bool);

    /**
     * @notice Kills the gauge so it cannot mint BAL.
     */
    function killGauge() external;

    /**
     * @notice Unkills the gauge so it can mint BAL again.
     */
    function unkillGauge() external;

    /**
     * @notice Sets a new relative weight cap for the gauge.
     * The value shall be normalized to 1e18, and not greater than MAX_RELATIVE_WEIGHT_CAP.
     * @param relativeWeightCap New relative weight cap.
     */
    function setRelativeWeightCap(uint256 relativeWeightCap) external;

    /**
     * @notice Gets the relative weight cap for the gauge.
     */
    function getRelativeWeightCap() external view returns (uint256);

    /**
     * @notice Returns the gauge's relative weight for a given time, capped to its relative weight cap attribute.
     * @param time Timestamp in the past or present.
     */
    function getCappedRelativeWeight(uint256 time) external view returns (uint256);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/ILiquidityGaugeFactory.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;
pragma experimental ABIEncoderV2;

import "./ILiquidityGauge.sol";

interface ILiquidityGaugeFactory {
    /**
     * @notice Returns true if `gauge` was created by this factory.
     */
    function isGaugeFromFactory(address gauge) external view returns (bool);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/ILMGetters.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "./IBalancerTokenAdmin.sol";
import "./IGaugeController.sol";

interface ILMGetters {
    /**
     * @notice Returns the address of the Balancer Token Admin contract
     */
    function getBalancerTokenAdmin() external view returns (IBalancerTokenAdmin);

    /**
     * @notice Returns the address of the Gauge Controller
     */
    function getGaugeController() external view returns (IGaugeController);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IMainnetBalancerMinter.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "./IBalancerMinter.sol";
import "./ILMGetters.sol";

/**
 * @dev Full L1 Balancer minter interface with singleton getters.
 */
interface IMainnetBalancerMinter is IBalancerMinter, ILMGetters {
    // solhint-disable-previous-line no-empty-blocks
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IRewardTokenDistributor.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;
pragma experimental ABIEncoderV2;

import "../solidity-utils/openzeppelin/IERC20.sol";

// For compatibility, we're keeping the same function names as in the original Curve code, including the mixed-case
// naming convention.
// solhint-disable func-name-mixedcase, var-name-mixedcase

interface IRewardTokenDistributor {
    struct Reward {
        IERC20 token;
        address distributor;
        uint256 period_finish;
        uint256 rate;
        uint256 last_update;
        uint256 integral;
    }

    function reward_tokens(uint256 index) external view returns (IERC20);

    function reward_data(IERC20 token) external view returns (Reward memory);

    function claim_rewards(address user) external;

    function add_reward(IERC20 rewardToken, address distributor) external;

    function set_reward_distributor(IERC20 rewardToken, address distributor) external;

    function deposit_reward_token(IERC20 rewardToken, uint256 amount) external;

    function claimable_reward(address rewardToken, address user) external view returns (uint256);

    function claimable_reward_write(address rewardToken, address user) external returns (uint256);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/ISmartWalletChecker.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

interface ISmartWalletChecker {
    function check(address contractAddress) external view returns (bool);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IStakelessGauge.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "./ILiquidityGauge.sol";

interface IStakelessGauge is ILiquidityGauge {
    function checkpoint() external payable returns (bool);

    function getRecipient() external view returns (address);
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IStakingLiquidityGauge.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;
pragma experimental ABIEncoderV2;

import "../solidity-utils/openzeppelin/IERC20.sol";

import "./ILiquidityGauge.sol";
import "./IRewardTokenDistributor.sol";

// For compatibility, we're keeping the same function names as in the original Curve code, including the mixed-case
// naming convention.
// solhint-disable func-name-mixedcase, var-name-mixedcase

interface IStakingLiquidityGauge is IRewardTokenDistributor, ILiquidityGauge, IERC20 {
    function initialize(address lpToken, uint256 relativeWeightCap) external;

    function lp_token() external view returns (IERC20);

    function deposit(uint256 value, address recipient) external;

    function withdraw(uint256 value) external;
}

// File: @balancer-labs/v2-interfaces/contracts/liquidity-mining/IVotingEscrow.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;
pragma experimental ABIEncoderV2;

import "./IAuthorizerAdaptor.sol";
import "./ISmartWalletChecker.sol";
import "../solidity-utils/openzeppelin/IERC20.sol";

// For compatibility, we're keeping the same function names as in the original Curve code, including the mixed-case
// naming convention.
// solhint-disable func-name-mixedcase

interface IVotingEscrow is IERC20 {
    struct Point {
        int128 bias;
        int128 slope; // - dweight / dt
        uint256 ts;
        uint256 blk; // block
    }

    function epoch() external view returns (uint256);

    function balanceOf(address user, uint256 timestamp) external view returns (uint256);

    function totalSupply(uint256 timestamp) external view returns (uint256);

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

    function point_history(uint256 timestamp) external view returns (Point memory);

    function user_point_history(address user, uint256 timestamp) external view returns (Point memory);

    function checkpoint() external;

    function admin() external view returns (IAuthorizerAdaptor);

    function smart_wallet_checker() external view returns (ISmartWalletChecker);

    function commit_smart_wallet_checker(address newSmartWalletChecker) external;

    function apply_smart_wallet_checker() external;

    function locked__end(address user) external view returns (uint256);
}

// File: @balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

// solhint-disable

/**
 * @dev Reverts if `condition` is false, with a revert reason containing `errorCode`. Only codes up to 999 are
 * supported.
 * Uses the default 'BAL' prefix for the error code
 */
function _require(bool condition, uint256 errorCode) pure {
    if (!condition) _revert(errorCode);
}

/**
 * @dev Reverts if `condition` is false, with a revert reason containing `errorCode`. Only codes up to 999 are
 * supported.
 */
function _require(
    bool condition,
    uint256 errorCode,
    bytes3 prefix
) pure {
    if (!condition) _revert(errorCode, prefix);
}

/**
 * @dev Reverts with a revert reason containing `errorCode`. Only codes up to 999 are supported.
 * Uses the default 'BAL' prefix for the error code
 */
function _revert(uint256 errorCode) pure {
    _revert(errorCode, 0x42414c); // This is the raw byte representation of "BAL"
}

/**
 * @dev Reverts with a revert reason containing `errorCode`. Only codes up to 999 are supported.
 */
function _revert(uint256 errorCode, bytes3 prefix) pure {
    uint256 prefixUint = uint256(uint24(prefix));
    // We're going to dynamically create a revert string based on the error code, with the following format:
    // 'BAL#{errorCode}'
    // where the code is left-padded with zeroes to three digits (so they range from 000 to 999).
    //
    // We don't have revert strings embedded in the contract to save bytecode size: it takes much less space to store a
    // number (8 to 16 bits) than the individual string characters.
    //
    // The dynamic string creation algorithm that follows could be implemented in Solidity, but assembly allows for a
    // much denser implementation, again saving bytecode size. Given this function unconditionally reverts, this is a
    // safe place to rely on it without worrying about how its usage might affect e.g. memory contents.
    assembly {
        // First, we need to compute the ASCII representation of the error code. We assume that it is in the 0-999
        // range, so we only need to convert three digits. To convert the digits to ASCII, we add 0x30, the value for
        // the '0' character.

        let units := add(mod(errorCode, 10), 0x30)

        errorCode := div(errorCode, 10)
        let tenths := add(mod(errorCode, 10), 0x30)

        errorCode := div(errorCode, 10)
        let hundreds := add(mod(errorCode, 10), 0x30)

        // With the individual characters, we can now construct the full string.
        // We first append the '#' character (0x23) to the prefix. In the case of 'BAL', it results in 0x42414c23 ('BAL#')
        // Then, we shift this by 24 (to provide space for the 3 bytes of the error code), and add the
        // characters to it, each shifted by a multiple of 8.
        // The revert reason is then shifted left by 200 bits (256 minus the length of the string, 7 characters * 8 bits
        // per character = 56) to locate it in the most significant part of the 256 slot (the beginning of a byte
        // array).
        let formattedPrefix := shl(24, add(0x23, shl(8, prefixUint)))

        let revertReason := shl(200, add(formattedPrefix, add(add(units, shl(8, tenths)), shl(16, hundreds))))

        // We can now encode the reason in memory, which can be safely overwritten as we're about to revert. The encoded
        // message will have the following layout:
        // [ revert reason identifier ] [ string location offset ] [ string length ] [ string contents ]

        // The Solidity revert reason identifier is 0x08c739a0, the function selector of the Error(string) function. We
        // also write zeroes to the next 28 bytes of memory, but those are about to be overwritten.
        mstore(0x0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
        // Next is the offset to the location of the string, which will be placed immediately after (20 bytes away).
        mstore(0x04, 0x0000000000000000000000000000000000000000000000000000000000000020)
        // The string length is fixed: 7 characters.
        mstore(0x24, 7)
        // Finally, the string itself is stored.
        mstore(0x44, revertReason)

        // Even if the string is only 7 bytes long, we need to return a full 32 byte slot containing it. The length of
        // the encoded message is therefore 4 + 32 + 32 + 32 = 100.
        revert(0, 100)
    }
}

library Errors {
    // Math
    uint256 internal constant ADD_OVERFLOW = 0;
    uint256 internal constant SUB_OVERFLOW = 1;
    uint256 internal constant SUB_UNDERFLOW = 2;
    uint256 internal constant MUL_OVERFLOW = 3;
    uint256 internal constant ZERO_DIVISION = 4;
    uint256 internal constant DIV_INTERNAL = 5;
    uint256 internal constant X_OUT_OF_BOUNDS = 6;
    uint256 internal constant Y_OUT_OF_BOUNDS = 7;
    uint256 internal constant PRODUCT_OUT_OF_BOUNDS = 8;
    uint256 internal constant INVALID_EXPONENT = 9;

    // Input
    uint256 internal constant OUT_OF_BOUNDS = 100;
    uint256 internal constant UNSORTED_ARRAY = 101;
    uint256 internal constant UNSORTED_TOKENS = 102;
    uint256 internal constant INPUT_LENGTH_MISMATCH = 103;
    uint256 internal constant ZERO_TOKEN = 104;
    uint256 internal constant INSUFFICIENT_DATA = 105;

    // Shared pools
    uint256 internal constant MIN_TOKENS = 200;
    uint256 internal constant MAX_TOKENS = 201;
    uint256 internal constant MAX_SWAP_FEE_PERCENTAGE = 202;
    uint256 internal constant MIN_SWAP_FEE_PERCENTAGE = 203;
    uint256 internal constant MINIMUM_BPT = 204;
    uint256 internal constant CALLER_NOT_VAULT = 205;
    uint256 internal constant UNINITIALIZED = 206;
    uint256 internal constant BPT_IN_MAX_AMOUNT = 207;
    uint256 internal constant BPT_OUT_MIN_AMOUNT = 208;
    uint256 internal constant EXPIRED_PERMIT = 209;
    uint256 internal constant NOT_TWO_TOKENS = 210;
    uint256 internal constant DISABLED = 211;

    // Pools
    uint256 internal constant MIN_AMP = 300;
    uint256 internal constant MAX_AMP = 301;
    uint256 internal constant MIN_WEIGHT = 302;
    uint256 internal constant MAX_STABLE_TOKENS = 303;
    uint256 internal constant MAX_IN_RATIO = 304;
    uint256 internal constant MAX_OUT_RATIO = 305;
    uint256 internal constant MIN_BPT_IN_FOR_TOKEN_OUT = 306;
    uint256 internal constant MAX_OUT_BPT_FOR_TOKEN_IN = 307;
    uint256 internal constant NORMALIZED_WEIGHT_INVARIANT = 308;
    uint256 internal constant INVALID_TOKEN = 309;
    uint256 internal constant UNHANDLED_JOIN_KIND = 310;
    uint256 internal constant ZERO_INVARIANT = 311;
    uint256 internal constant ORACLE_INVALID_SECONDS_QUERY = 312;
    uint256 internal constant ORACLE_NOT_INITIALIZED = 313;
    uint256 internal constant ORACLE_QUERY_TOO_OLD = 314;
    uint256 internal constant ORACLE_INVALID_INDEX = 315;
    uint256 internal constant ORACLE_BAD_SECS = 316;
    uint256 internal constant AMP_END_TIME_TOO_CLOSE = 317;
    uint256 internal constant AMP_ONGOING_UPDATE = 318;
    uint256 internal constant AMP_RATE_TOO_HIGH = 319;
    uint256 internal constant AMP_NO_ONGOING_UPDATE = 320;
    uint256 internal constant STABLE_INVARIANT_DIDNT_CONVERGE = 321;
    uint256 internal constant STABLE_GET_BALANCE_DIDNT_CONVERGE = 322;
    uint256 internal constant RELAYER_NOT_CONTRACT = 323;
    uint256 internal constant BASE_POOL_RELAYER_NOT_CALLED = 324;
    uint256 internal constant REBALANCING_RELAYER_REENTERED = 325;
    uint256 internal constant GRADUAL_UPDATE_TIME_TRAVEL = 326;
    uint256 internal constant SWAPS_DISABLED = 327;
    uint256 internal constant CALLER_IS_NOT_LBP_OWNER = 328;
    uint256 internal constant PRICE_RATE_OVERFLOW = 329;
    uint256 internal constant INVALID_JOIN_EXIT_KIND_WHILE_SWAPS_DISABLED = 330;
    uint256 internal constant WEIGHT_CHANGE_TOO_FAST = 331;
    uint256 internal constant LOWER_GREATER_THAN_UPPER_TARGET = 332;
    uint256 internal constant UPPER_TARGET_TOO_HIGH = 333;
    uint256 internal constant UNHANDLED_BY_LINEAR_POOL = 334;
    uint256 internal constant OUT_OF_TARGET_RANGE = 335;
    uint256 internal constant UNHANDLED_EXIT_KIND = 336;
    uint256 internal constant UNAUTHORIZED_EXIT = 337;
    uint256 internal constant MAX_MANAGEMENT_SWAP_FEE_PERCENTAGE = 338;
    uint256 internal constant UNHANDLED_BY_MANAGED_POOL = 339;
    uint256 internal constant UNHANDLED_BY_PHANTOM_POOL = 340;
    uint256 internal constant TOKEN_DOES_NOT_HAVE_RATE_PROVIDER = 341;
    uint256 internal constant INVALID_INITIALIZATION = 342;
    uint256 internal constant OUT_OF_NEW_TARGET_RANGE = 343;
    uint256 internal constant FEATURE_DISABLED = 344;
    uint256 internal constant UNINITIALIZED_POOL_CONTROLLER = 345;
    uint256 internal constant SET_SWAP_FEE_DURING_FEE_CHANGE = 346;
    uint256 internal constant SET_SWAP_FEE_PENDING_FEE_CHANGE = 347;
    uint256 internal constant CHANGE_TOKENS_DURING_WEIGHT_CHANGE = 348;
    uint256 internal constant CHANGE_TOKENS_PENDING_WEIGHT_CHANGE = 349;
    uint256 internal constant MAX_WEIGHT = 350;
    uint256 internal constant UNAUTHORIZED_JOIN = 351;
    uint256 internal constant MAX_MANAGEMENT_AUM_FEE_PERCENTAGE = 352;
    uint256 internal constant FRACTIONAL_TARGET = 353;
    uint256 internal constant ADD_OR_REMOVE_BPT = 354;
    uint256 internal constant INVALID_CIRCUIT_BREAKER_BOUNDS = 355;
    uint256 internal constant CIRCUIT_BREAKER_TRIPPED = 356;
    uint256 internal constant MALICIOUS_QUERY_REVERT = 357;
    uint256 internal constant JOINS_EXITS_DISABLED = 358;

    // Lib
    uint256 internal constant REENTRANCY = 400;
    uint256 internal constant SENDER_NOT_ALLOWED = 401;
    uint256 internal constant PAUSED = 402;
    uint256 internal constant PAUSE_WINDOW_EXPIRED = 403;
    uint256 internal constant MAX_PAUSE_WINDOW_DURATION = 404;
    uint256 internal constant MAX_BUFFER_PERIOD_DURATION = 405;
    uint256 internal constant INSUFFICIENT_BALANCE = 406;
    uint256 internal constant INSUFFICIENT_ALLOWANCE = 407;
    uint256 internal constant ERC20_TRANSFER_FROM_ZERO_ADDRESS = 408;
    uint256 internal constant ERC20_TRANSFER_TO_ZERO_ADDRESS = 409;
    uint256 internal constant ERC20_MINT_TO_ZERO_ADDRESS = 410;
    uint256 internal constant ERC20_BURN_FROM_ZERO_ADDRESS = 411;
    uint256 internal constant ERC20_APPROVE_FROM_ZERO_ADDRESS = 412;
    uint256 internal constant ERC20_APPROVE_TO_ZERO_ADDRESS = 413;
    uint256 internal constant ERC20_TRANSFER_EXCEEDS_ALLOWANCE = 414;
    uint256 internal constant ERC20_DECREASED_ALLOWANCE_BELOW_ZERO = 415;
    uint256 internal constant ERC20_TRANSFER_EXCEEDS_BALANCE = 416;
    uint256 internal constant ERC20_BURN_EXCEEDS_ALLOWANCE = 417;
    uint256 internal constant SAFE_ERC20_CALL_FAILED = 418;
    uint256 internal constant ADDRESS_INSUFFICIENT_BALANCE = 419;
    uint256 internal constant ADDRESS_CANNOT_SEND_VALUE = 420;
    uint256 internal constant SAFE_CAST_VALUE_CANT_FIT_INT256 = 421;
    uint256 internal constant GRANT_SENDER_NOT_ADMIN = 422;
    uint256 internal constant REVOKE_SENDER_NOT_ADMIN = 423;
    uint256 internal constant RENOUNCE_SENDER_NOT_ALLOWED = 424;
    uint256 internal constant BUFFER_PERIOD_EXPIRED = 425;
    uint256 internal constant CALLER_IS_NOT_OWNER = 426;
    uint256 internal constant NEW_OWNER_IS_ZERO = 427;
    uint256 internal constant CODE_DEPLOYMENT_FAILED = 428;
    uint256 internal constant CALL_TO_NON_CONTRACT = 429;
    uint256 internal constant LOW_LEVEL_CALL_FAILED = 430;
    uint256 internal constant NOT_PAUSED = 431;
    uint256 internal constant ADDRESS_ALREADY_ALLOWLISTED = 432;
    uint256 internal constant ADDRESS_NOT_ALLOWLISTED = 433;
    uint256 internal constant ERC20_BURN_EXCEEDS_BALANCE = 434;
    uint256 internal constant INVALID_OPERATION = 435;
    uint256 internal constant CODEC_OVERFLOW = 436;
    uint256 internal constant IN_RECOVERY_MODE = 437;
    uint256 internal constant NOT_IN_RECOVERY_MODE = 438;
    uint256 internal constant INDUCED_FAILURE = 439;
    uint256 internal constant EXPIRED_SIGNATURE = 440;
    uint256 internal constant MALFORMED_SIGNATURE = 441;
    uint256 internal constant SAFE_CAST_VALUE_CANT_FIT_UINT64 = 442;
    uint256 internal constant UNHANDLED_FEE_TYPE = 443;
    uint256 internal constant BURN_FROM_ZERO = 444;

    // Vault
    uint256 internal constant INVALID_POOL_ID = 500;
    uint256 internal constant CALLER_NOT_POOL = 501;
    uint256 internal constant SENDER_NOT_ASSET_MANAGER = 502;
    uint256 internal constant USER_DOESNT_ALLOW_RELAYER = 503;
    uint256 internal constant INVALID_SIGNATURE = 504;
    uint256 internal constant EXIT_BELOW_MIN = 505;
    uint256 internal constant JOIN_ABOVE_MAX = 506;
    uint256 internal constant SWAP_LIMIT = 507;
    uint256 internal constant SWAP_DEADLINE = 508;
    uint256 internal constant CANNOT_SWAP_SAME_TOKEN = 509;
    uint256 internal constant UNKNOWN_AMOUNT_IN_FIRST_SWAP = 510;
    uint256 internal constant MALCONSTRUCTED_MULTIHOP_SWAP = 511;
    uint256 internal constant INTERNAL_BALANCE_OVERFLOW = 512;
    uint256 internal constant INSUFFICIENT_INTERNAL_BALANCE = 513;
    uint256 internal constant INVALID_ETH_INTERNAL_BALANCE = 514;
    uint256 internal constant INVALID_POST_LOAN_BALANCE = 515;
    uint256 internal constant INSUFFICIENT_ETH = 516;
    uint256 internal constant UNALLOCATED_ETH = 517;
    uint256 internal constant ETH_TRANSFER = 518;
    uint256 internal constant CANNOT_USE_ETH_SENTINEL = 519;
    uint256 internal constant TOKENS_MISMATCH = 520;
    uint256 internal constant TOKEN_NOT_REGISTERED = 521;
    uint256 internal constant TOKEN_ALREADY_REGISTERED = 522;
    uint256 internal constant TOKENS_ALREADY_SET = 523;
    uint256 internal constant TOKENS_LENGTH_MUST_BE_2 = 524;
    uint256 internal constant NONZERO_TOKEN_BALANCE = 525;
    uint256 internal constant BALANCE_TOTAL_OVERFLOW = 526;
    uint256 internal constant POOL_NO_TOKENS = 527;
    uint256 internal constant INSUFFICIENT_FLASH_LOAN_BALANCE = 528;

    // Fees
    uint256 internal constant SWAP_FEE_PERCENTAGE_TOO_HIGH = 600;
    uint256 internal constant FLASH_LOAN_FEE_PERCENTAGE_TOO_HIGH = 601;
    uint256 internal constant INSUFFICIENT_FLASH_LOAN_FEE_AMOUNT = 602;
    uint256 internal constant AUM_FEE_PERCENTAGE_TOO_HIGH = 603;

    // FeeSplitter
    uint256 internal constant SPLITTER_FEE_PERCENTAGE_TOO_HIGH = 700;

    // Misc
    uint256 internal constant UNIMPLEMENTED = 998;
    uint256 internal constant SHOULD_NOT_HAPPEN = 999;
}

// File: @balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/IAuthentication.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

interface IAuthentication {
    /**
     * @dev Returns the action identifier associated with the external function described by `selector`.
     */
    function getActionId(bytes4 selector) external view returns (bytes32);
}

// File: @balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/ISignaturesValidator.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

/**
 * @dev Interface for the SignatureValidator helper, used to support meta-transactions.
 */
interface ISignaturesValidator {
    /**
     * @dev Returns the EIP712 domain separator.
     */
    function getDomainSeparator() external view returns (bytes32);

    /**
     * @dev Returns the next nonce used by an address to sign messages.
     */
    function getNextNonce(address user) external view returns (uint256);
}

// File: @balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/ITemporarilyPausable.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

/**
 * @dev Interface for the TemporarilyPausable helper.
 */
interface ITemporarilyPausable {
    /**
     * @dev Emitted every time the pause state changes by `_setPaused`.
     */
    event PausedStateChanged(bool paused);

    /**
     * @dev Returns the current paused state.
     */
    function getPausedState()
        external
        view
        returns (
            bool paused,
            uint256 pauseWindowEndTime,
            uint256 bufferPeriodEndTime
        );
}

// File: @balancer-labs/v2-interfaces/contracts/solidity-utils/misc/IWETH.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

import "../openzeppelin/IERC20.sol";

/**
 * @dev Interface for WETH9.
 * See https://github.com/gnosis/canonical-weth/blob/0dd1ea3e295eef916d0c6223ec63141137d22d67/contracts/WETH9.sol
 */
interface IWETH is IERC20 {
    function deposit() external payable;

    function withdraw(uint256 amount) external;
}

// File: @balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.7.0 <0.9.0;

/**
 * @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: @balancer-labs/v2-interfaces/contracts/vault/IAsset.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

/**
 * @dev This is an empty interface used to represent either ERC20-conforming token contracts or ETH (using the zero
 * address sentinel value). We're just relying on the fact that `interface` can be used to declare new address-like
 * types.
 *
 * This concept is unrelated to a Pool's Asset Managers.
 */
interface IAsset {
    // solhint-disable-previous-line no-empty-blocks
}

// File: @balancer-labs/v2-interfaces/contracts/vault/IAuthorizer.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

interface IAuthorizer {
    /**
     * @dev Returns true if `account` can perform the action described by `actionId` in the contract `where`.
     */
    function canPerform(
        bytes32 actionId,
        address account,
        address where
    ) external view returns (bool);
}

// File: @balancer-labs/v2-interfaces/contracts/vault/IFlashLoanRecipient.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;

// Inspired by Aave Protocol's IFlashLoanReceiver.

import "../solidity-utils/openzeppelin/IERC20.sol";

interface IFlashLoanRecipient {
    /**
     * @dev When `flashLoan` is called on the Vault, it invokes the `receiveFlashLoan` hook on the recipient.
     *
     * At the time of the call, the Vault will have transferred `amounts` for `tokens` to the recipient. Before this
     * call returns, the recipient must have transferred `amounts` plus `feeAmounts` for each token back to the
     * Vault, or else the entire flash loan will revert.
     *
     * `userData` is the same value passed in the `IVault.flashLoan` call.
     */
    function receiveFlashLoan(
        IERC20[] memory tokens,
        uint256[] memory amounts,
        uint256[] memory feeAmounts,
        bytes memory userData
    ) external;
}

// File: @balancer-labs/v2-interfaces/contracts/vault/IProtocolFeesCollector.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.7.0 <0.9.0;
pragma experimental ABIEncoderV2;

import "../solidity-utils/openzeppelin/IERC20.sol";

import "./IVault.sol";
import "./IAuthorizer.sol";

interface IProtocolFeesCollector {
    event SwapFeePercentageChanged(uint256 newSwapFeePercentage);
    event FlashLoanFeePercentageChanged(uint256 newFlashLoanFeePercentage);

    function withdrawCollectedFees(
        IERC20[] calldata tokens,
        uint256[] calldata amounts,
        address recipient
    ) external;

    function setSwapFeePercentage(uint256 newSwapFeePercentage) external;

    function setFlashLoanFeePercentage(uint256 newFlashLoanFeePercentage) external;

    function getSwapFeePercentage() external view returns (uint256);

    function getFlashLoanFeePercentage() external view returns (uint256);

    function getCollectedFeeAmounts(IERC20[] memory tokens) external view returns (uint256[] memory feeAmounts);

    function getAuthorizer() external view returns (IAuthorizer);

    function vault() external view returns (IVault);
}

// File: @balancer-labs/v2-interfaces/contracts/vault/IVault.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma experimental ABIEncoderV2;

import "../solidity-utils/openzeppelin/IERC20.sol";
import "../solidity-utils/helpers/IAuthentication.sol";
import "../solidity-utils/helpers/ISignaturesValidator.sol";
import "../solidity-utils/helpers/ITemporarilyPausable.sol";
import "../solidity-utils/misc/IWETH.sol";

import "./IAsset.sol";
import "./IAuthorizer.sol";
import "./IFlashLoanRecipient.sol";
import "./IProtocolFeesCollector.sol";

pragma solidity >=0.7.0 <0.9.0;

/**
 * @dev Full external interface for the Vault core contract - no external or public methods exist in the contract that
 * don't override one of these declarations.
 */
interface IVault is ISignaturesValidator, ITemporarilyPausable, IAuthentication {
    // Generalities about the Vault:
    //
    // - Whenever documentation refers to 'tokens', it strictly refers to ERC20-compliant token contracts. Tokens are
    // transferred out of the Vault by calling the `IERC20.transfer` function, and transferred in by calling
    // `IERC20.transferFrom`. In these cases, the sender must have previously allowed the Vault to use their tokens by
    // calling `IERC20.approve`. The only deviation from the ERC20 standard that is supported is functions not returning
    // a boolean value: in these scenarios, a non-reverting call is assumed to be successful.
    //
    // - All non-view functions in the Vault are non-reentrant: calling them while another one is mid-execution (e.g.
    // while execution control is transferred to a token contract during a swap) will result in a revert. View
    // functions can be called in a re-reentrant way, but doing so might cause them to return inconsistent results.
    // Contracts calling view functions in the Vault must make sure the Vault has not already been entered.
    //
    // - View functions revert if referring to either unregistered Pools, or unregistered tokens for registered Pools.

    // Authorizer
    //
    // Some system actions are permissioned, like setting and collecting protocol fees. This permissioning system exists
    // outside of the Vault in the Authorizer contract: the Vault simply calls the Authorizer to check if the caller
    // can perform a given action.

    /**
     * @dev Returns the Vault's Authorizer.
     */
    function getAuthorizer() external view returns (IAuthorizer);

    /**
     * @dev Sets a new Authorizer for the Vault. The caller must be allowed by the current Authorizer to do this.
     *
     * Emits an `AuthorizerChanged` event.
     */
    function setAuthorizer(IAuthorizer newAuthorizer) external;

    /**
     * @dev Emitted when a new authorizer is set by `setAuthorizer`.
     */
    event AuthorizerChanged(IAuthorizer indexed newAuthorizer);

    // Relayers
    //
    // Additionally, it is possible for an account to perform certain actions on behalf of another one, using their
    // Vault ERC20 allowance and Internal Balance. These accounts are said to be 'relayers' for these Vault functions,
    // and are expected to be smart contracts with sound authentication mechanisms. For an account to be able to wield
    // this power, two things must occur:
    //  - The Authorizer must grant the account the permission to be a relayer for the relevant Vault function. This
    //    means that Balancer governance must approve each individual contract to act as a relayer for the intended
    //    functions.
    //  - Each user must approve the relayer to act on their behalf.
    // This double protection means users cannot be tricked into approving malicious relayers (because they will not
    // have been allowed by the Authorizer via governance), nor can malicious relayers approved by a compromised
    // Authorizer or governance drain user funds, since they would also need to be approved by each individual user.

    /**
     * @dev Returns true if `user` has approved `relayer` to act as a relayer for them.
     */
    function hasApprovedRelayer(address user, address relayer) external view returns (bool);

    /**
     * @dev Allows `relayer` to act as a relayer for `sender` if `approved` is true, and disallows it otherwise.
     *
     * Emits a `RelayerApprovalChanged` event.
     */
    function setRelayerApproval(
        address sender,
        address relayer,
        bool approved
    ) external;

    /**
     * @dev Emitted every time a relayer is approved or disapproved by `setRelayerApproval`.
     */
    event RelayerApprovalChanged(address indexed relayer, address indexed sender, bool approved);

    // Internal Balance
    //
    // Users can deposit tokens into the Vault, where they are allocated to their Internal Balance, and later
    // transferred or withdrawn. It can also be used as a source of tokens when joining Pools, as a destination
    // when exiting them, and as either when performing swaps. This usage of Internal Balance results in greatly reduced
    // gas costs when compared to relying on plain ERC20 transfers, leading to large savings for frequent users.
    //
    // Internal Balance management features batching, which means a single contract call can be used to perform multiple
    // operations of different kinds, with different senders and recipients, at once.

    /**
     * @dev Returns `user`'s Internal Balance for a set of tokens.
     */
    function getInternalBalance(address user, IERC20[] memory tokens) external view returns (uint256[] memory);

    /**
     * @dev Performs a set of user balance operations, which involve Internal Balance (deposit, withdraw or transfer)
     * and plain ERC20 transfers using the Vault's allowance. This last feature is particularly useful for relayers, as
     * it lets integrators reuse a user's Vault allowance.
     *
     * For each operation, if the caller is not `sender`, it must be an authorized relayer for them.
     */
    function manageUserBalance(UserBalanceOp[] memory ops) external payable;

    /**
     * @dev Data for `manageUserBalance` operations, which include the possibility for ETH to be sent and received
     without manual WETH wrapping or unwrapping.
     */
    struct UserBalanceOp {
        UserBalanceOpKind kind;
        IAsset asset;
        uint256 amount;
        address sender;
        address payable recipient;
    }

    // There are four possible operations in `manageUserBalance`:
    //
    // - DEPOSIT_INTERNAL
    // Increases the Internal Balance of the `recipient` account by transferring tokens from the corresponding
    // `sender`. The sender must have allowed the Vault to use their tokens via `IERC20.approve()`.
    //
    // ETH can be used by passing the ETH sentinel value as the asset and forwarding ETH in the call: it will be wrapped
    // and deposited as WETH. Any ETH amount remaining will be sent back to the caller (not the sender, which is
    // relevant for relayers).
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - WITHDRAW_INTERNAL
    // Decreases the Internal Balance of the `sender` account by transferring tokens to the `recipient`.
    //
    // ETH can be used by passing the ETH sentinel value as the asset. This will deduct WETH instead, unwrap it and send
    // it to the recipient as ETH.
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - TRANSFER_INTERNAL
    // Transfers tokens from the Internal Balance of the `sender` account to the Internal Balance of `recipient`.
    //
    // Reverts if the ETH sentinel value is passed.
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - TRANSFER_EXTERNAL
    // Transfers tokens from `sender` to `recipient`, using the Vault's ERC20 allowance. This is typically used by
    // relayers, as it lets them reuse a user's Vault allowance.
    //
    // Reverts if the ETH sentinel value is passed.
    //
    // Emits an `ExternalBalanceTransfer` event.

    enum UserBalanceOpKind { DEPOSIT_INTERNAL, WITHDRAW_INTERNAL, TRANSFER_INTERNAL, TRANSFER_EXTERNAL }

    /**
     * @dev Emitted when a user's Internal Balance changes, either from calls to `manageUserBalance`, or through
     * interacting with Pools using Internal Balance.
     *
     * Because Internal Balance works exclusively with ERC20 tokens, ETH deposits and withdrawals will use the WETH
     * address.
     */
    event InternalBalanceChanged(address indexed user, IERC20 indexed token, int256 delta);

    /**
     * @dev Emitted when a user's Vault ERC20 allowance is used by the Vault to transfer tokens to an external account.
     */
    event ExternalBalanceTransfer(IERC20 indexed token, address indexed sender, address recipient, uint256 amount);

    // Pools
    //
    // There are three specialization settings for Pools, which allow for cheaper swaps at the cost of reduced
    // functionality:
    //
    //  - General: no specialization, suited for all Pools. IGeneralPool is used for swap request callbacks, passing the
    // balance of all tokens in the Pool. These Pools have the largest swap costs (because of the extra storage reads),
    // which increase with the number of registered tokens.
    //
    //  - Minimal Swap Info: IMinimalSwapInfoPool is used instead of IGeneralPool, which saves gas by only passing the
    // balance of the two tokens involved in the swap. This is suitable for some pricing algorithms, like the weighted
    // constant product one popularized by Balancer V1. Swap costs are smaller compared to general Pools, and are
    // independent of the number of registered tokens.
    //
    //  - Two Token: only allows two tokens to be registered. This achieves the lowest possible swap gas cost. Like
    // minimal swap info Pools, these are called via IMinimalSwapInfoPool.

    enum PoolSpecialization { GENERAL, MINIMAL_SWAP_INFO, TWO_TOKEN }

    /**
     * @dev Registers the caller account as a Pool with a given specialization setting. Returns the Pool's ID, which
     * is used in all Pool-related functions. Pools cannot be deregistered, nor can the Pool's specialization be
     * changed.
     *
     * The caller is expected to be a smart contract that implements either `IGeneralPool` or `IMinimalSwapInfoPool`,
     * depending on the chosen specialization setting. This contract is known as the Pool's contract.
     *
     * Note that the same contract may register itself as multiple Pools with unique Pool IDs, or in other words,
     * multiple Pools may share the same contract.
     *
     * Emits a `PoolRegistered` event.
     */
    function registerPool(PoolSpecialization specialization) external returns (bytes32);

    /**
     * @dev Emitted when a Pool is registered by calling `registerPool`.
     */
    event PoolRegistered(bytes32 indexed poolId, address indexed poolAddress, PoolSpecialization specialization);

    /**
     * @dev Returns a Pool's contract address and specialization setting.
     */
    function getPool(bytes32 poolId) external view returns (address, PoolSpecialization);

    /**
     * @dev Registers `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
     *
     * Pools can only interact with tokens they have registered. Users join a Pool by transferring registered tokens,
     * exit by receiving registered tokens, and can only swap registered tokens.
     *
     * Each token can only be registered once. For Pools with the Two Token specialization, `tokens` must have a length
     * of two, that is, both tokens must be registered in the same `registerTokens` call, and they must be sorted in
     * ascending order.
     *
     * The `tokens` and `assetManagers` arrays must have the same length, and each entry in these indicates the Asset
     * Manager for the corresponding token. Asset Managers can manage a Pool's tokens via `managePoolBalance`,
     * depositing and withdrawing them directly, and can even set their balance to arbitrary amounts. They are therefore
     * expected to be highly secured smart contracts with sound design principles, and the decision to register an
     * Asset Manager should not be made lightly.
     *
     * Pools can choose not to assign an Asset Manager to a given token by passing in the zero address. Once an Asset
     * Manager is set, it cannot be changed except by deregistering the associated token and registering again with a
     * different Asset Manager.
     *
     * Emits a `TokensRegistered` event.
     */
    function registerTokens(
        bytes32 poolId,
        IERC20[] memory tokens,
        address[] memory assetManagers
    ) external;

    /**
     * @dev Emitted when a Pool registers tokens by calling `registerTokens`.
     */
    event TokensRegistered(bytes32 indexed poolId, IERC20[] tokens, address[] assetManagers);

    /**
     * @dev Deregisters `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
     *
     * Only registered tokens (via `registerTokens`) can be deregistered. Additionally, they must have zero total
     * balance. For Pools with the Two Token specialization, `tokens` must have a length of two, that is, both tokens
     * must be deregistered in the same `deregisterTokens` call.
     *
     * A deregistered token can be re-registered later on, possibly with a different Asset Manager.
     *
     * Emits a `TokensDeregistered` event.
     */
    function deregisterTokens(bytes32 poolId, IERC20[] memory tokens) external;

    /**
     * @dev Emitted when a Pool deregisters tokens by calling `deregisterTokens`.
     */
    event TokensDeregistered(bytes32 indexed poolId, IERC20[] tokens);

    /**
     * @dev Returns detailed information for a Pool's registered token.
     *
     * `cash` is the number of tokens the Vault currently holds for the Pool. `managed` is the number of tokens
     * withdrawn and held outside the Vault by the Pool's token Asset Manager. The Pool's total balance for `token`
     * equals the sum of `cash` and `managed`.
     *
     * Internally, `cash` and `managed` are stored using 112 bits. No action can ever cause a Pool's token `cash`,
     * `managed` or `total` balance to be greater than 2^112 - 1.
     *
     * `lastChangeBlock` is the number of the block in which `token`'s total balance was last modified (via either a
     * join, exit, swap, or Asset Manager update). This value is useful to avoid so-called 'sandwich attacks', for
     * example when developing price oracles. A change of zero (e.g. caused by a swap with amount zero) is considered a
     * change for this purpose, and will update `lastChangeBlock`.
     *
     * `assetManager` is the Pool's token Asset Manager.
     */
    function getPoolTokenInfo(bytes32 poolId, IERC20 token)
        external
        view
        returns (
            uint256 cash,
            uint256 managed,
            uint256 lastChangeBlock,
            address assetManager
        );

    /**
     * @dev Returns a Pool's registered tokens, the total balance for each, and the latest block when *any* of
     * the tokens' `balances` changed.
     *
     * The order of the `tokens` array is the same order that will be used in `joinPool`, `exitPool`, as well as in all
     * Pool hooks (where applicable). Calls to `registerTokens` and `deregisterTokens` may change this order.
     *
     * If a Pool only registers tokens once, and these are sorted in ascending order, they will be stored in the same
     * order as passed to `registerTokens`.
     *
     * Total balances include both tokens held by the Vault and those withdrawn by the Pool's Asset Managers. These are
     * the amounts used by joins, exits and swaps. For a detailed breakdown of token balances, use `getPoolTokenInfo`
     * instead.
     */
    function getPoolTokens(bytes32 poolId)
        external
        view
        returns (
            IERC20[] memory tokens,
            uint256[] memory balances,
            uint256 lastChangeBlock
        );

    /**
     * @dev Called by users to join a Pool, which transfers tokens from `sender` into the Pool's balance. This will
     * trigger custom Pool behavior, which will typically grant something in return to `recipient` - often tokenized
     * Pool shares.
     *
     * If the caller is not `sender`, it must be an authorized relayer for them.
     *
     * The `assets` and `maxAmountsIn` arrays must have the same length, and each entry indicates the maximum amount
     * to send for each asset. The amounts to send are decided by the Pool and not the Vault: it just enforces
     * these maximums.
     *
     * If joining a Pool that holds WETH, it is possible to send ETH directly: the Vault will do the wrapping. To enable
     * this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead of the
     * WETH address. Note that it is not possible to combine ETH and WETH in the same join. Any excess ETH will be sent
     * back to the caller (not the sender, which is important for relayers).
     *
     * `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
     * interacting with Pools that register and deregister tokens frequently. If sending ETH however, the array must be
     * sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the final
     * `assets` array might not be sorted. Pools with no registered tokens cannot be joined.
     *
     * If `fromInternalBalance` is true, the caller's Internal Balance will be preferred: ERC20 transfers will only
     * be made for the difference between the requested amount and Internal Balance (if any). Note that ETH cannot be
     * withdrawn from Internal Balance: attempting to do so will trigger a revert.
     *
     * This causes the Vault to call the `IBasePool.onJoinPool` hook on the Pool's contract, where Pools implement
     * their own custom logic. This typically requires additional information from the user (such as the expected number
     * of Pool shares). This can be encoded in the `userData` argument, which is ignored by the Vault and passed
     * directly to the Pool's contract, as is `recipient`.
     *
     * Emits a `PoolBalanceChanged` event.
     */
    function joinPool(
        bytes32 poolId,
        address sender,
        address recipient,
        JoinPoolRequest memory request
    ) external payable;

    struct JoinPoolRequest {
        IAsset[] assets;
        uint256[] maxAmountsIn;
        bytes userData;
        bool fromInternalBalance;
    }

    /**
     * @dev Called by users to exit a Pool, which transfers tokens from the Pool's balance to `recipient`. This will
     * trigger custom Pool behavior, which will typically ask for something in return from `sender` - often tokenized
     * Pool shares. The amount of tokens that can be withdrawn is limited by the Pool's `cash` balance (see
     * `getPoolTokenInfo`).
     *
     * If the caller is not `sender`, it must be an authorized relayer for them.
     *
     * The `tokens` and `minAmountsOut` arrays must have the same length, and each entry in these indicates the minimum
     * token amount to receive for each token contract. The amounts to send are decided by the Pool and not the Vault:
     * it just enforces these minimums.
     *
     * If exiting a Pool that holds WETH, it is possible to receive ETH directly: the Vault will do the unwrapping. To
     * enable this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead
     * of the WETH address. Note that it is not possible to combine ETH and WETH in the same exit.
     *
     * `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
     * interacting with Pools that register and deregister tokens frequently. If receiving ETH however, the array must
     * be sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the
     * final `assets` array might not be sorted. Pools with no registered tokens cannot be exited.
     *
     * If `toInternalBalance` is true, the tokens will be deposited to `recipient`'s Internal Balance. Otherwise,
     * an ERC20 transfer will be performed. Note that ETH cannot be deposited to Internal Balance: attempting to
     * do so will trigger a revert.
     *
     * `minAmountsOut` is the minimum amount of tokens the user expects to get out of the Pool, for each token in the
     * `tokens` array. This array must match the Pool's registered tokens.
     *
     * This causes the Vault to call the `IBasePool.onExitPool` hook on the Pool's contract, where Pools implement
     * their own custom logic. This typically requires additional information from the user (such as the expected number
     * of Pool shares to return). This can be encoded in the `userData` argument, which is ignored by the Vault and
     * passed directly to the Pool's contract.
     *
     * Emits a `PoolBalanceChanged` event.
     */
    function exitPool(
        bytes32 poolId,
        address sender,
        address payable recipient,
        ExitPoolRequest memory request
    ) external;

    struct ExitPoolRequest {
        IAsset[] assets;
        uint256[] minAmountsOut;
        bytes userData;
        bool toInternalBalance;
    }

    /**
     * @dev Emitted when a user joins or exits a Pool by calling `joinPool` or `exitPool`, respectively.
     */
    event PoolBalanceChanged(
        bytes32 indexed poolId,
        address indexed liquidityProvider,
        IERC20[] tokens,
        int256[] deltas,
        uint256[] protocolFeeAmounts
    );

    enum PoolBalanceChangeKind { JOIN, EXIT }

    // Swaps
    //
    // Users can swap tokens with Pools by calling the `swap` and `batchSwap` functions. To do this,
    // they need not trust Pool contracts in any way: all security checks are made by the Vault. They must however be
    // aware of the Pools' pricing algorithms in order to estimate the prices Pools will quote.
    //
    // The `swap` function executes a single swap, while `batchSwap` can perform multiple swaps in sequence.
    // In each individual swap, tokens of one kind are sent from the sender to the Pool (this is the 'token in'),
    // and tokens of another kind are sent from the Pool to the recipient in exchange (this is the 'token out').
    // More complex swaps, such as one token in to multiple tokens out can be achieved by batching together
    // individual swaps.
    //
    // There are two swap kinds:
    //  - 'given in' swaps, where the amount of tokens in (sent to the Pool) is known, and the Pool determines (via the
    // `onSwap` hook) the amount of tokens out (to send to the recipient).
    //  - 'given out' swaps, where the amount of tokens out (received from the Pool) is known, and the Pool determines
    // (via the `onSwap` hook) the amount of tokens in (to receive from the sender).
    //
    // Additionally, it is possible to chain swaps using a placeholder input amount, which the Vault replaces with
    // the calculated output of the previous swap. If the previous swap was 'given in', this will be the calculated
    // tokenOut amount. If the previous swap was 'given out', it will use the calculated tokenIn amount. These extended
    // swaps are known as 'multihop' swaps, since they 'hop' through a number of intermediate tokens before arriving at
    // the final intended token.
    //
    // In all cases, tokens are only transferred in and out of the Vault (or withdrawn from and deposited into Internal
    // Balance) after all individual swaps have been completed, and the net token balance change computed. This makes
    // certain swap patterns, such as multihops, or swaps that interact with the same token pair in multiple Pools, cost
    // much less gas than they would otherwise.
    //
    // It also means that under certain conditions it is possible to perform arbitrage by swapping with multiple
    // Pools in a way that results in net token movement out of the Vault (profit), with no tokens being sent in (only
    // updating the Pool's internal accounting).
    //
    // To protect users from front-running or the market changing rapidly, they supply a list of 'limits' for each token
    // involved in the swap, where either the maximum number of tokens to send (by passing a positive value) or the
    // minimum amount of tokens to receive (by passing a negative value) is specified.
    //
    // Additionally, a 'deadline' timestamp can also be provided, forcing the swap to fail if it occurs after
    // this point in time (e.g. if the transaction failed to be included in a block promptly).
    //
    // If interacting with Pools that hold WETH, it is possible to both send and receive ETH directly: the Vault will do
    // the wrapping and unwrapping. To enable this mechanism, the IAsset sentinel value (the zero address) must be
    // passed in the `assets` array instead of the WETH address. Note that it is possible to combine ETH and WETH in the
    // same swap. Any excess ETH will be sent back to the caller (not the sender, which is relevant for relayers).
    //
    // Finally, Internal Balance can be used when either sending or receiving tokens.

    enum SwapKind { GIVEN_IN, GIVEN_OUT }

    /**
     * @dev Performs a swap with a single Pool.
     *
     * If the swap is 'given in' (the number of tokens to send to the Pool is known), it returns the amount of tokens
     * taken from the Pool, which must be greater than or equal to `limit`.
     *
     * If the swap is 'given out' (the number of tokens to take from the Pool is known), it returns the amount of tokens
     * sent to the Pool, which must be less than or equal to `limit`.
     *
     * Internal Balance usage and the recipient are determined by the `funds` struct.
     *
     * Emits a `Swap` event.
     */
    function swap(
        SingleSwap memory singleSwap,
        FundManagement memory funds,
        uint256 limit,
        uint256 deadline
    ) external payable returns (uint256);

    /**
     * @dev Data for a single swap executed by `swap`. `amount` is either `amountIn` or `amountOut` depending on
     * the `kind` value.
     *
     * `assetIn` and `assetOut` are either token addresses, or the IAsset sentinel value for ETH (the zero address).
     * Note that Pools never interact with ETH directly: it will be wrapped to or unwrapped from WETH by the Vault.
     *
     * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
     * used to extend swap behavior.
     */
    struct SingleSwap {
        bytes32 poolId;
        SwapKind kind;
        IAsset assetIn;
        IAsset assetOut;
        uint256 amount;
        bytes userData;
    }

    /**
     * @dev Performs a series of swaps with one or multiple Pools. In each individual swap, the caller determines either
     * the amount of tokens sent to or received from the Pool, depending on the `kind` value.
     *
     * Returns an array with the net Vault asset balance deltas. Positive amounts represent tokens (or ETH) sent to the
     * Vault, and negative amounts represent tokens (or ETH) sent by the Vault. Each delta corresponds to the asset at
     * the same index in the `assets` array.
     *
     * Swaps are executed sequentially, in the order specified by the `swaps` array. Each array element describes a
     * Pool, the token to be sent to this Pool, the token to receive from it, and an amount that is either `amountIn` or
     * `amountOut` depending on the swap kind.
     *
     * Multihop swaps can be executed by passing an `amount` value of zero for a swap. This will cause the amount in/out
     * of the previous swap to be used as the amount in for the current one. In a 'given in' swap, 'tokenIn' must equal
     * the previous swap's `tokenOut`. For a 'given out' swap, `tokenOut` must equal the previous swap's `tokenIn`.
     *
     * The `assets` array contains the addresses of all assets involved in the swaps. These are either token addresses,
     * or the IAsset sentinel value for ETH (the zero address). Each entry in the `swaps` array specifies tokens in and
     * out by referencing an index in `assets`. Note that Pools never interact with ETH directly: it will be wrapped to
     * or unwrapped from WETH by the Vault.
     *
     * Internal Balance usage, sender, and recipient are determined by the `funds` struct. The `limits` array specifies
     * the minimum or maximum amount of each token the vault is allowed to transfer.
     *
     * `batchSwap` can be used to make a single swap, like `swap` does, but doing so requires more gas than the
     * equivalent `swap` call.
     *
     * Emits `Swap` events.
     */
    function batchSwap(
        SwapKind kind,
        BatchSwapStep[] memory swaps,
        IAsset[] memory assets,
        FundManagement memory funds,
        int256[] memory limits,
        uint256 deadline
    ) external payable returns (int256[] memory);

    /**
     * @dev Data for each individual swap executed by `batchSwap`. The asset in and out fields are indexes into the
     * `assets` array passed to that function, and ETH assets are converted to WETH.
     *
     * If `amount` is zero, the multihop mechanism is used to determine the actual amount based on the amount in/out
     * from the previous swap, depending on the swap kind.
     *
     * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
     * used to extend swap behavior.
     */
    struct BatchSwapStep {
        bytes32 poolId;
        uint256 assetInIndex;
        uint256 assetOutIndex;
        uint256 amount;
        bytes userData;
    }

    /**
     * @dev Emitted for each individual swap performed by `swap` or `batchSwap`.
     */
    event Swap(
        bytes32 indexed poolId,
        IERC20 indexed tokenIn,
        IERC20 indexed tokenOut,
        uint256 amountIn,
        uint256 amountOut
    );

    /**
     * @dev All tokens in a swap are either sent from the `sender` account to the Vault, or from the Vault to the
     * `recipient` account.
     *
     * If the caller is not `sender`, it must be an authorized relayer for them.
     *
     * If `fromInternalBalance` is true, the `sender`'s Internal Balance will be preferred, performing an ERC20
     * transfer for the difference between the requested amount and the User's Internal Balance (if any). The `sender`
     * must have allowed the Vault to use their tokens via `IERC20.approve()`. This matches the behavior of
     * `joinPool`.
     *
     * If `toInternalBalance` is true, tokens will be deposited to `recipient`'s internal balance instead of
     * transferred. This matches the behavior of `exitPool`.
     *
     * Note that ETH cannot be deposited to or withdrawn from Internal Balance: attempting to do so will trigger a
     * revert.
     */
    struct FundManagement {
        address sender;
        bool fromInternalBalance;
        address payable recipient;
        bool toInternalBalance;
    }

    /**
     * @dev Simulates a call to `batchSwap`, returning an array of Vault asset deltas. Calls to `swap` cannot be
     * simulated directly, but an equivalent `batchSwap` call can and will yield the exact same result.
     *
     * Each element in the array corresponds to the asset at the same index, and indicates the number of tokens (or ETH)
     * the Vault would take from the sender (if positive) or send to the recipient (if negative). The arguments it
     * receives are the same that an equivalent `batchSwap` call would receive.
     *
     * Unlike `batchSwap`, this function performs no checks on the sender or recipient field in the `funds` struct.
     * This makes it suitable to be called by off-chain applications via eth_call without needing to hold tokens,
     * approve them for the Vault, or even know a user's address.
     *
     * Note that this function is not 'view' (due to implementation details): the client code must explicitly execute
     * eth_call instead of eth_sendTransaction.
     */
    function queryBatchSwap(
        SwapKind kind,
        BatchSwapStep[] memory swaps,
        IAsset[] memory assets,
        FundManagement memory funds
    ) external returns (int256[] memory assetDeltas);

    // Flash Loans

    /**
     * @dev Performs a 'flash loan', sending tokens to `recipient`, executing the `receiveFlashLoan` hook on it,
     * and then reverting unless the tokens plus a proportional protocol fee have been returned.
     *
     * The `tokens` and `amounts` arrays must have the same length, and each entry in these indicates the loan amount
     * for each token contract. `tokens` must be sorted in ascending order.
     *
     * The 'userData' field is ignored by the Vault, and forwarded as-is to `recipient` as part of the
     * `receiveFlashLoan` call.
     *
     * Emits `FlashLoan` events.
     */
    function flashLoan(
        IFlashLoanRecipient recipient,
        IERC20[] memory tokens,
        uint256[] memory amounts,
        bytes memory userData
    ) external;

    /**
     * @dev Emitted for each individual flash loan performed by `flashLoan`.
     */
    event FlashLoan(IFlashLoanRecipient indexed recipient, IERC20 indexed token, uint256 amount, uint256 feeAmount);

    // Asset Management
    //
    // Each token registered for a Pool can be assigned an Asset Manager, which is able to freely withdraw the Pool's
    // tokens from the Vault, deposit them, or assign arbitrary values to its `managed` balance (see
    // `getPoolTokenInfo`). This makes them extremely powerful and dangerous. Even if an Asset Manager only directly
    // controls one of the tokens in a Pool, a malicious manager could set that token's balance to manipulate the
    // prices of the other tokens, and then drain the Pool with swaps. The risk of using Asset Managers is therefore
    // not constrained to the tokens they are managing, but extends to the entire Pool's holdings.
    //
    // However, a properly designed Asset Manager smart contract can be safely used for the Pool's benefit,
    // for example by lending unused tokens out for interest, or using them to participate in voting protocols.
    //
    // This concept is unrelated to the IAsset interface.

    /**
     * @dev Performs a set of Pool balance operations, which may be either withdrawals, deposits or updates.
     *
     * Pool Balance management features batching, which means a single contract call can be used to perform multiple
     * operations of different kinds, with different Pools and tokens, at once.
     *
     * For each operation, the caller must be registered as the Asset Manager for `token` in `poolId`.
     */
    function managePoolBalance(PoolBalanceOp[] memory ops) external;

    struct PoolBalanceOp {
        PoolBalanceOpKind kind;
        bytes32 poolId;
        IERC20 token;
        uint256 amount;
    }

    /**
     * Withdrawals decrease the Pool's cash, but increase its managed balance, leaving the total balance unchanged.
     *
     * Deposits increase the Pool's cash, but decrease its managed balance, leaving the total balance unchanged.
     *
     * Updates don't affect the Pool's cash balance, but because the managed balance changes, it does alter the total.
     * The external amount can be either increased or decreased by this call (i.e., reporting a gain or a loss).
     */
    enum PoolBalanceOpKind { WITHDRAW, DEPOSIT, UPDATE }

    /**
     * @dev Emitted when a Pool's token Asset Manager alters its balance via `managePoolBalance`.
     */
    event PoolBalanceManaged(
        bytes32 indexed poolId,
        address indexed assetManager,
        IERC20 indexed token,
        int256 cashDelta,
        int256 managedDelta
    );

    // Protocol Fees
    //
    // Some operations cause the Vault to collect tokens in the form of protocol fees, which can then be withdrawn by
    // permissioned accounts.
    //
    // There are two kinds of protocol fees:
    //
    //  - flash loan fees: charged on all flash loans, as a percentage of the amounts lent.
    //
    //  - swap fees: a percentage of the fees charged by Pools when performing swaps. For a number of reasons, including
    // swap gas costs and interface simplicity, protocol swap fees are not charged on each individual swap. Rather,
    // Pools are expected to keep track of how much they have charged in swap fees, and pay any outstanding debts to the
    // Vault when they are joined or exited. This prevents users from joining a Pool with unpaid debt, as well as
    // exiting a Pool in debt without first paying their share.

    /**
     * @dev Returns the current protocol fee module.
     */
    function getProtocolFeesCollector() external view returns (IProtocolFeesCollector);

    /**
     * @dev Safety mechanism to pause most Vault operations in the event of an emergency - typically detection of an
     * error in some part of the system.
     *
     * The Vault can only be paused during an initial time period, after which pausing is forever disabled.
     *
     * While the contract is paused, the following features are disabled:
     * - depositing and transferring internal balance
     * - transferring external balance (using the Vault's allowance)
     * - swaps
     * - joining Pools
     * - Asset Manager interactions
     *
     * Internal Balance can still be withdrawn, and Pools exited.
     */
    function setPaused(bool paused) external;

    /**
     * @dev Returns the Vault's WETH instance.
     */
    function WETH() external view returns (IWETH);
    // solhint-disable-previous-line func-name-mixedcase
}

// File: @balancer-labs/v2-solidity-utils/contracts/helpers/Authentication.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/IAuthentication.sol";

/**
 * @dev Building block for performing access control on external functions.
 *
 * This contract is used via the `authenticate` modifier (or the `_authenticateCaller` function), which can be applied
 * to external functions to only make them callable by authorized accounts.
 *
 * Derived contracts must implement the `_canPerform` function, which holds the actual access control logic.
 */
abstract contract Authentication is IAuthentication {
    bytes32 private immutable _actionIdDisambiguator;

    /**
     * @dev The main purpose of the `actionIdDisambiguator` is to prevent accidental function selector collisions in
     * multi contract systems.
     *
     * There are two main uses for it:
     *  - if the contract is a singleton, any unique identifier can be used to make the associated action identifiers
     *    unique. The contract's own address is a good option.
     *  - if the contract belongs to a family that shares action identifiers for the same functions, an identifier
     *    shared by the entire family (and no other contract) should be used instead.
     */
    constructor(bytes32 actionIdDisambiguator) {
        _actionIdDisambiguator = actionIdDisambiguator;
    }

    /**
     * @dev Reverts unless the caller is allowed to call this function. Should only be applied to external functions.
     */
    modifier authenticate() {
        _authenticateCaller();
        _;
    }

    /**
     * @dev Reverts unless the caller is allowed to call the entry point function.
     */
    function _authenticateCaller() internal view {
        bytes32 actionId = getActionId(msg.sig);
        _require(_canPerform(actionId, msg.sender), Errors.SENDER_NOT_ALLOWED);
    }

    function getActionId(bytes4 selector) public view override returns (bytes32) {
        // Each external function is dynamically assigned an action identifier as the hash of the disambiguator and the
        // function selector. Disambiguation is necessary to avoid potential collisions in the function selectors of
        // multiple contracts.
        return keccak256(abi.encodePacked(_actionIdDisambiguator, selector));
    }

    function _canPerform(bytes32 actionId, address user) internal view virtual returns (bool);
}

// File: @balancer-labs/v2-solidity-utils/contracts/helpers/SingletonAuthentication.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/vault/IVault.sol";

import "./Authentication.sol";

abstract contract SingletonAuthentication is Authentication {
    IVault private immutable _vault;

    // Use the contract's own address to disambiguate action identifiers
    constructor(IVault vault) Authentication(bytes32(uint256(address(this)))) {
        _vault = vault;
    }

    /**
     * @notice Returns the Balancer Vault
     */
    function getVault() public view returns (IVault) {
        return _vault;
    }

    /**
     * @notice Returns the Authorizer
     */
    function getAuthorizer() public view returns (IAuthorizer) {
        return getVault().getAuthorizer();
    }

    function _canPerform(bytes32 actionId, address account) internal view override returns (bool) {
        return getAuthorizer().canPerform(actionId, account, address(this));
    }

    function _canPerform(
        bytes32 actionId,
        address account,
        address where
    ) internal view returns (bool) {
        return getAuthorizer().canPerform(actionId, account, where);
    }
}

// File: @balancer-labs/v2-solidity-utils/contracts/math/Math.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow checks.
 * Adapted from OpenZeppelin's SafeMath library.
 */
library Math {
    // solhint-disable no-inline-assembly

    /**
     * @dev Returns the absolute value of a signed integer.
     */
    function abs(int256 a) internal pure returns (uint256 result) {
        // Equivalent to:
        // result = a > 0 ? uint256(a) : uint256(-a)
        assembly {
            let s := sar(255, a)
            result := sub(xor(a, s), s)
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers of 256 bits, reverting on overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        _require(c >= a, Errors.ADD_OVERFLOW);
        return c;
    }

    /**
     * @dev Returns the addition of two signed integers, reverting 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), Errors.ADD_OVERFLOW);
        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers of 256 bits, reverting on overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        _require(b <= a, Errors.SUB_OVERFLOW);
        uint256 c = a - b;
        return c;
    }

    /**
     * @dev Returns the subtraction of two signed integers, reverting 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), Errors.SUB_OVERFLOW);
        return c;
    }

    /**
     * @dev Returns the largest of two numbers of 256 bits.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256 result) {
        // Equivalent to:
        // result = (a < b) ? b : a;
        assembly {
            result := sub(a, mul(sub(a, b), lt(a, b)))
        }
    }

    /**
     * @dev Returns the smallest of two numbers of 256 bits.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256 result) {
        // Equivalent to `result = (a < b) ? a : b`
        assembly {
            result := sub(a, mul(sub(a, b), gt(a, b)))
        }
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a * b;
        _require(a == 0 || c / a == b, Errors.MUL_OVERFLOW);
        return c;
    }

    function div(
        uint256 a,
        uint256 b,
        bool roundUp
    ) internal pure returns (uint256) {
        return roundUp ? divUp(a, b) : divDown(a, b);
    }

    function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
        _require(b != 0, Errors.ZERO_DIVISION);
        return a / b;
    }

    function divUp(uint256 a, uint256 b) internal pure returns (uint256 result) {
        _require(b != 0, Errors.ZERO_DIVISION);

        // Equivalent to:
        // result = a == 0 ? 0 : 1 + (a - 1) / b;
        assembly {
            result := mul(iszero(iszero(a)), add(1, div(sub(a, 1), b)))
        }
    }
}

// File: @balancer-labs/v2-solidity-utils/contracts/openzeppelin/Address.sol



// SPDX-License-Identifier: MIT

// Based on the Address library from OpenZeppelin Contracts, altered by removing the `isContract` checks on
// `functionCall` and `functionDelegateCall` in order to save gas, as the recipients are known to be contracts.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";

/**
 * @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;
    }

    // solhint-disable max-line-length

    /**
     * @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, Errors.ADDRESS_INSUFFICIENT_BALANCE);

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        _require(success, Errors.ADDRESS_CANNOT_SEND_VALUE);
    }

    /**
     * @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:
     *
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call(data);
        return verifyCallResult(success, returndata);
    }

    // solhint-enable max-line-length

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but passing some native ETH as msg.value to the call.
     *
     * _Available since v3.4._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return verifyCallResult(success, returndata);
    }

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

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling up the
     * revert reason or using the one provided.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                _revert(Errors.LOW_LEVEL_CALL_FAILED);
            }
        }
    }
}

// File: @balancer-labs/v2-solidity-utils/contracts/openzeppelin/EnumerableSet.sol



// SPDX-License-Identifier: MIT

// Based on the EnumerableSet library from OpenZeppelin Contracts, altered to remove the base private functions that
// work on bytes32, replacing them with a native implementation for address and bytes32 values, to reduce bytecode
// size and runtime costs.
// The `unchecked_at` function was also added, which allows for more gas efficient data reads in some scenarios.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";

/**
 * @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 {
    // The original OpenZeppelin implementation uses a generic Set type with bytes32 values: this was replaced with
    // AddressSet, which uses address keys natively, resulting in more dense bytecode.

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

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, if it was not already present.
     */
    function add(AddressSet storage set, address value) internal 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(AddressSet storage set, address value) internal 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;

            // The swap is only necessary if we're not removing the last element
            if (toDeleteIndex != lastIndex) {
                address 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(AddressSet storage set, address value) internal view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(AddressSet storage set) internal 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(AddressSet storage set, uint256 index) internal view returns (address) {
        _require(set._values.length > index, Errors.OUT_OF_BOUNDS);
        return unchecked_at(set, index);
    }

    /**
     * @dev Same as {at}, except this doesn't revert if `index` it outside of the set (i.e. if it is equal or larger
     * than {length}). O(1).
     *
     * This function performs one less storage read than {at}, but should only be used when `index` is known to be
     * within bounds.
     */
    // solhint-disable-next-line func-name-mixedcase
    function unchecked_at(AddressSet storage set, uint256 index) internal view returns (address) {
        return set._values[index];
    }

    function rawIndexOf(AddressSet storage set, address value) internal view returns (uint256) {
        return set._indexes[value] - 1;
    }

    struct Bytes32Set {
        // 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(Bytes32Set storage set, bytes32 value) internal 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(Bytes32Set storage set, bytes32 value) internal 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;

            // The swap is only necessary if we're not removing the last element
            if (toDeleteIndex != lastIndex) {
                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(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(Bytes32Set storage set) internal 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(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        _require(set._values.length > index, Errors.OUT_OF_BOUNDS);
        return unchecked_at(set, index);
    }

    /**
     * @dev Same as {at}, except this doesn't revert if `index` it outside of the set (i.e. if it is equal or larger
     * than {length}). O(1).
     *
     * This function performs one less storage read than {at}, but should only be used when `index` is known to be
     * within bounds.
     */
    // solhint-disable-next-line func-name-mixedcase
    function unchecked_at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return set._values[index];
    }

    function rawIndexOf(Bytes32Set storage set, bytes32 value) internal view returns (uint256) {
        return set._indexes[value] - 1;
    }
}

// File: @balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT

// Based on the ReentrancyGuard library from OpenZeppelin Contracts, altered to reduce bytecode size.
// Modifier code is inlined by the compiler, which causes its code to appear multiple times in the codebase. By using
// private functions, we achieve the same end result with slightly higher runtime gas costs, but reduced bytecode size.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract 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() {
        _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() {
        _enterNonReentrant();
        _;
        _exitNonReentrant();
    }

    function _enterNonReentrant() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        _require(_status != _ENTERED, Errors.REENTRANCY);

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

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

// File: @balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol



// SPDX-License-Identifier: MIT

// Based on the ReentrancyGuard library from OpenZeppelin Contracts, altered to reduce gas costs.
// The `safeTransfer` and `safeTransferFrom` functions assume that `token` is a contract (an account with code), and
// work differently from the OpenZeppelin version if it is not.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/solidity-utils/helpers/BalancerErrors.sol";
import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.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 {

    function safeApprove(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        // Some contracts need their allowance reduced to 0 before setting it to an arbitrary amount.
        if (value != 0 && token.allowance(address(this), address(to)) != 0) {
            _callOptionalReturn(address(token), abi.encodeWithSelector(token.approve.selector, to, 0));
        }

        _callOptionalReturn(address(token), abi.encodeWithSelector(token.approve.selector, to, value));
    }

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

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(address(token), abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @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).
     *
     * WARNING: `token` is assumed to be a contract: calls to EOAs will *not* revert.
     */
    function _callOptionalReturn(address 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.
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = token.call(data);

        // If the low-level call didn't succeed we return whatever was returned from it.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            if eq(success, 0) {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
        }

        // Finally we check the returndata size is either zero or true - note that this check will always pass for EOAs
        _require(returndata.length == 0 || abi.decode(returndata, (bool)), Errors.SAFE_ERC20_CALL_FAILED);
    }
}

// File: contracts/admin/GaugeAdder.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;

import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IGaugeAdder.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IStakingLiquidityGauge.sol";
import "@balancer-labs/v2-interfaces/contracts/vault/IVault.sol";

import "@balancer-labs/v2-solidity-utils/contracts/helpers/SingletonAuthentication.sol";
import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";
import "@balancer-labs/v2-solidity-utils/contracts/helpers/Authentication.sol";

contract GaugeAdder is IGaugeAdder, SingletonAuthentication, ReentrancyGuard {
    // This is the gauge type as used in the GaugeController for Ethereum gauges, which we'll use for all gauges of all
    // networks from now on.
    int128 private constant _ETHEREUM_GAUGE_CONTROLLER_TYPE = 2;

    bytes32 private immutable _ethereum = keccak256(abi.encodePacked("Ethereum"));
    IGaugeController private immutable _gaugeController;
    IERC20 private immutable _balWethBpt;
    IAuthorizerAdaptorEntrypoint private _authorizerAdaptorEntrypoint;

    // Registered gauge types. Append-only.
    string[] private _gaugeTypes;

    // Mapping from gauge type to address of approved factory for that type
    mapping(string => ILiquidityGaugeFactory) private _gaugeTypeFactory;

    constructor(IGaugeController gaugeController, IAuthorizerAdaptorEntrypoint authorizerAdaptorEntrypoint)
        SingletonAuthentication(gaugeController.admin().getVault())
    {
        _gaugeController = gaugeController;
        _authorizerAdaptorEntrypoint = authorizerAdaptorEntrypoint;

        // Cache the BAL 80 WETH 20 BPT on this contract.
        _balWethBpt = gaugeController.token();
    }

    modifier withValidGaugeType(string memory gaugeType) {
        require(_isValidGaugeType(gaugeType), "Invalid gauge type");
        _;
    }

    /// @inheritdoc IGaugeAdder
    function getAuthorizerAdaptorEntrypoint() external view override returns (IAuthorizerAdaptorEntrypoint) {
        return _authorizerAdaptorEntrypoint;
    }

    /// @inheritdoc IGaugeAdder
    function getGaugeController() external view override returns (IGaugeController) {
        return _gaugeController;
    }

    /// @inheritdoc IGaugeAdder
    function getGaugeTypes() external view override returns (string[] memory) {
        return _gaugeTypes;
    }

    /// @inheritdoc IGaugeAdder
    function getGaugeTypeAtIndex(uint256 index) external view override returns (string memory) {
        return _gaugeTypes[index];
    }

    /// @inheritdoc IGaugeAdder
    function getGaugeTypesCount() external view override returns (uint256) {
        return _gaugeTypes.length;
    }

    /// @inheritdoc IGaugeAdder
    function isValidGaugeType(string memory gaugeType) external view override returns (bool) {
        return _isValidGaugeType(gaugeType);
    }

    /// @inheritdoc IGaugeAdder
    function getFactoryForGaugeType(string memory gaugeType)
        external
        view
        override
        withValidGaugeType(gaugeType)
        returns (ILiquidityGaugeFactory)
    {
        return _gaugeTypeFactory[gaugeType];
    }

    /// @inheritdoc IGaugeAdder
    function isGaugeFromValidFactory(address gauge, string memory gaugeType)
        external
        view
        override
        withValidGaugeType(gaugeType)
        returns (bool)
    {
        return _isGaugeFromValidFactory(gauge, gaugeType);
    }

    // Admin Functions

    /// @inheritdoc IGaugeAdder
    function addGaugeType(string memory gaugeType) external override authenticate {
        require(bytes(gaugeType).length > 0, "Gauge type cannot be empty");
        require(!_isValidGaugeType(gaugeType), "Gauge type already added");

        _gaugeTypes.push(gaugeType);

        emit GaugeTypeAdded(gaugeType, gaugeType);
    }

    /// @inheritdoc IGaugeAdder
    function addGauge(address gauge, string memory gaugeType)
        external
        override
        authenticate
        withValidGaugeType(gaugeType)
    {
        if (keccak256(abi.encodePacked(gaugeType)) == _ethereum) {
            IERC20 pool = IStakingLiquidityGauge(gauge).lp_token();
            require(pool != _balWethBpt, "Cannot add gauge for 80/20 BAL-WETH BPT");
        }

        _addGauge(gauge, gaugeType);
    }

    /// @inheritdoc IGaugeAdder
    function setGaugeFactory(ILiquidityGaugeFactory factory, string memory gaugeType)
        external
        override
        authenticate
        withValidGaugeType(gaugeType)
    {
        // Sanity check that calling `isGaugeFromFactory` won't revert
        require(
            (factory == ILiquidityGaugeFactory(0)) || (!factory.isGaugeFromFactory(address(0))),
            "Invalid factory implementation"
        );

        _gaugeTypeFactory[gaugeType] = factory;

        emit GaugeFactorySet(gaugeType, gaugeType, factory);
    }

    // Internal functions

    function _isGaugeFromValidFactory(address gauge, string memory gaugeType) internal view returns (bool) {
        ILiquidityGaugeFactory gaugeFactory = _gaugeTypeFactory[gaugeType];
        return gaugeFactory == ILiquidityGaugeFactory(0) ? false : gaugeFactory.isGaugeFromFactory(gauge);
    }

    /**
     * @dev Adds `gauge` to the GaugeController with type `gaugeType` and an initial weight of zero
     */
    function _addGauge(address gauge, string memory gaugeType) private {
        require(_isGaugeFromValidFactory(gauge, gaugeType), "Invalid gauge");

        // `_gaugeController` enforces that duplicate gauges may not be added so we do not need to check here.
        _authorizerAdaptorEntrypoint.performAction(
            address(_gaugeController),
            abi.encodeWithSelector(IGaugeController.add_gauge.selector, gauge, _ETHEREUM_GAUGE_CONTROLLER_TYPE)
        );
    }

    function _isValidGaugeType(string memory gaugeType) internal view returns (bool) {
        bytes32 gaugeTypeHash = keccak256(abi.encodePacked(gaugeType));
        for (uint256 i = 0; i < _gaugeTypes.length; ++i) {
            if (gaugeTypeHash == keccak256(abi.encodePacked(_gaugeTypes[i]))) {
                return true;
            }
        }

        return false;
    }
}

// File: contracts/gauges/arbitrum/ArbitrumRootGauge.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IArbitrumFeeProvider.sol";
import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/SafeERC20.sol";

import "../StakelessGauge.sol";
import "./IGatewayRouter.sol";

contract ArbitrumRootGauge is StakelessGauge {
    using SafeERC20 for IERC20;

    address private immutable _gateway;
    IGatewayRouter private immutable _gatewayRouter;
    IArbitrumFeeProvider private immutable _factory;

    address private _recipient;

    constructor(IMainnetBalancerMinter minter, IGatewayRouter gatewayRouter) StakelessGauge(minter) {
        _gateway = gatewayRouter.getGateway(address(minter.getBalancerToken()));
        _gatewayRouter = gatewayRouter;
        _factory = IArbitrumFeeProvider(msg.sender);
    }

    function initialize(address recipient, uint256 relativeWeightCap) external {
        // This will revert in all calls except the first one
        __StakelessGauge_init(relativeWeightCap);

        _recipient = recipient;
    }

    function getRecipient() external view override returns (address) {
        return _recipient;
    }

    function _postMintAction(uint256 mintAmount) internal override {
        // Token needs to be approved on the gateway NOT the gateway router
        _balToken.safeApprove(_gateway, mintAmount);

        (uint256 gasLimit, uint256 gasPrice, uint256 maxSubmissionCost) = _factory.getArbitrumFees();
        uint256 totalBridgeCost = _getTotalBridgeCost(gasLimit, gasPrice, maxSubmissionCost);
        require(msg.value == totalBridgeCost, "Incorrect msg.value passed");

        // After bridging, the BAL should arrive on Arbitrum within 10 minutes. If it
        // does not, the L2 transaction may have failed due to an insufficient amount
        // within `max_submission_cost + (gas_limit * gas_price)`
        // In this case, the transaction can be manually broadcasted on Arbitrum by calling
        // `ArbRetryableTicket(0x000000000000000000000000000000000000006e).redeem(redemption-TxID)`
        // The calldata for this manual transaction is easily obtained by finding the reverted
        // transaction in the tx history for 0x000000000000000000000000000000000000006e on Arbiscan.
        // https://developer.offchainlabs.com/docs/l1_l2_messages#retryable-transaction-lifecycle
        _gatewayRouter.outboundTransfer{ value: totalBridgeCost }(
            _balToken,
            _recipient,
            mintAmount,
            gasLimit,
            gasPrice,
            abi.encode(maxSubmissionCost, "")
        );
    }

    function getTotalBridgeCost() external view returns (uint256) {
        (uint256 gasLimit, uint256 gasPrice, uint256 maxSubmissionCost) = _factory.getArbitrumFees();
        return _getTotalBridgeCost(gasLimit, gasPrice, maxSubmissionCost);
    }

    function _getTotalBridgeCost(
        uint256 gasLimit,
        uint256 gasPrice,
        uint256 maxSubmissionCost
    ) internal pure returns (uint256) {
        return gasLimit * gasPrice + maxSubmissionCost;
    }
}

// File: contracts/gauges/arbitrum/IGatewayRouter.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";

interface IGatewayRouter {
    function outboundTransfer(
        IERC20 token,
        address recipient,
        uint256 amount,
        uint256 gasLimit,
        uint256 gasPrice,
        bytes calldata data
    ) external payable;

    function getGateway(address token) external view returns (address gateway);
}

// File: contracts/gauges/L2GaugeCheckpointer.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;

import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IAuthorizerAdaptorEntrypoint.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IGaugeAdder.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IGaugeController.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IL2GaugeCheckpointer.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IStakelessGauge.sol";

import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/Address.sol";
import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/EnumerableSet.sol";
import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";

import "../admin/GaugeAdder.sol";
import "./arbitrum/ArbitrumRootGauge.sol";

/**
 * @title L2 Gauge Checkpointer
 * @notice Implements IL2GaugeCheckpointer; refer to it for API documentation.
 */
contract L2GaugeCheckpointer is IL2GaugeCheckpointer, ReentrancyGuard, SingletonAuthentication {
    using EnumerableSet for EnumerableSet.AddressSet;

    bytes32 private immutable _arbitrum = keccak256(abi.encodePacked("Arbitrum"));

    mapping(string => EnumerableSet.AddressSet) private _gauges;
    IAuthorizerAdaptorEntrypoint private immutable _authorizerAdaptorEntrypoint;
    IGaugeAdder private immutable _gaugeAdder;
    IGaugeController private immutable _gaugeController;

    constructor(IGaugeAdder gaugeAdder, IAuthorizerAdaptorEntrypoint authorizerAdaptorEntrypoint)
        SingletonAuthentication(authorizerAdaptorEntrypoint.getVault())
    {
        _gaugeAdder = gaugeAdder;
        _authorizerAdaptorEntrypoint = authorizerAdaptorEntrypoint;
        _gaugeController = gaugeAdder.getGaugeController();
    }

    modifier withValidGaugeType(string memory gaugeType) {
        require(_gaugeAdder.isValidGaugeType(gaugeType), "Invalid gauge type");
        _;
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function getGaugeAdder() external view override returns (IGaugeAdder) {
        return _gaugeAdder;
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function addGaugesWithVerifiedType(string memory gaugeType, IStakelessGauge[] calldata gauges)
        external
        override
        withValidGaugeType(gaugeType)
        authenticate
    {
        // This is a permissioned call, so we can assume that the gauges' type matches the given one.
        // Therefore, we indicate `_addGauges` not to verify the gauge type.
        _addGauges(gaugeType, gauges, true);
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function addGauges(string memory gaugeType, IStakelessGauge[] calldata gauges)
        external
        override
        withValidGaugeType(gaugeType)
    {
        // Since everyone can call this method, the type needs to be verified in the internal `_addGauges` method.
        _addGauges(gaugeType, gauges, false);
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function removeGauges(string memory gaugeType, IStakelessGauge[] calldata gauges)
        external
        override
        withValidGaugeType(gaugeType)
    {
        EnumerableSet.AddressSet storage gaugesForType = _gauges[gaugeType];

        for (uint256 i = 0; i < gauges.length; i++) {
            // Gauges added must come from a valid factory and exist in the controller, and they can't be removed from
            // them. Therefore, the only required check at this point is whether the gauge was killed.
            IStakelessGauge gauge = gauges[i];
            require(gauge.is_killed(), "Gauge was not killed");
            require(gaugesForType.remove(address(gauge)), "Gauge was not added to the checkpointer");

            emit IL2GaugeCheckpointer.GaugeRemoved(gauge, gaugeType, gaugeType);
        }
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function hasGauge(string memory gaugeType, IStakelessGauge gauge)
        external
        view
        override
        withValidGaugeType(gaugeType)
        returns (bool)
    {
        return _gauges[gaugeType].contains(address(gauge));
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function getTotalGauges(string memory gaugeType)
        external
        view
        override
        withValidGaugeType(gaugeType)
        returns (uint256)
    {
        return _gauges[gaugeType].length();
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function getGaugeAtIndex(string memory gaugeType, uint256 index)
        external
        view
        override
        withValidGaugeType(gaugeType)
        returns (IStakelessGauge)
    {
        return IStakelessGauge(_gauges[gaugeType].at(index));
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function checkpointGaugesAboveRelativeWeight(uint256 minRelativeWeight) external payable override nonReentrant {
        // solhint-disable-next-line not-rely-on-time
        uint256 currentPeriod = _roundDownTimestamp(block.timestamp);

        string[] memory gaugeTypes = _gaugeAdder.getGaugeTypes();
        for (uint256 i = 0; i < gaugeTypes.length; ++i) {
            _checkpointGauges(gaugeTypes[i], minRelativeWeight, currentPeriod);
        }

        // Send back any leftover ETH to the caller.
        Address.sendValue(msg.sender, address(this).balance);
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function checkpointGaugesOfTypeAboveRelativeWeight(string memory gaugeType, uint256 minRelativeWeight)
        external
        payable
        override
        nonReentrant
        withValidGaugeType(gaugeType)
    {
        // solhint-disable-next-line not-rely-on-time
        uint256 currentPeriod = _roundDownTimestamp(block.timestamp);

        _checkpointGauges(gaugeType, minRelativeWeight, currentPeriod);

        _returnLeftoverEthIfAny();
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function checkpointSingleGauge(string memory gaugeType, address gauge) external payable override nonReentrant {
        uint256 checkpointCost = getSingleBridgeCost(gaugeType, gauge);

        _authorizerAdaptorEntrypoint.performAction{ value: checkpointCost }(
            gauge,
            abi.encodeWithSelector(IStakelessGauge.checkpoint.selector)
        );

        _returnLeftoverEthIfAny();
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function getSingleBridgeCost(string memory gaugeType, address gauge) public view override returns (uint256) {
        require(_gauges[gaugeType].contains(gauge), "Gauge was not added to the checkpointer");

        if (keccak256(abi.encodePacked(gaugeType)) == _arbitrum) {
            return ArbitrumRootGauge(gauge).getTotalBridgeCost();
        } else {
            return 0;
        }
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function getTotalBridgeCost(uint256 minRelativeWeight) external view override returns (uint256) {
        // solhint-disable-next-line not-rely-on-time
        uint256 currentPeriod = _roundDownTimestamp(block.timestamp);
        uint256 totalArbitrumGauges = _gauges["Arbitrum"].length();
        EnumerableSet.AddressSet storage arbitrumGauges = _gauges["Arbitrum"];
        uint256 totalCost;

        for (uint256 i = 0; i < totalArbitrumGauges; ++i) {
            address gauge = arbitrumGauges.unchecked_at(i);
            // Skip gauges that are below the threshold.
            if (_gaugeController.gauge_relative_weight(gauge, currentPeriod) < minRelativeWeight) {
                continue;
            }

            // Cost per gauge might not be the same if gauges come from different factories, so we add each
            // gauge's bridge cost individually.
            totalCost += ArbitrumRootGauge(gauge).getTotalBridgeCost();
        }
        return totalCost;
    }

    /// @inheritdoc IL2GaugeCheckpointer
    function isValidGaugeType(string memory gaugeType) external view override returns (bool) {
        return _gaugeAdder.isValidGaugeType(gaugeType);
    }

    function _addGauges(
        string memory gaugeType,
        IStakelessGauge[] calldata gauges,
        bool isGaugeTypeVerified
    ) internal {
        EnumerableSet.AddressSet storage gaugesForType = _gauges[gaugeType];

        for (uint256 i = 0; i < gauges.length; i++) {
            IStakelessGauge gauge = gauges[i];
            // Gauges must come from a valid factory to be added to the gauge controller, so gauges that don't pass
            // the valid factory check will be rejected by the controller.
            require(_gaugeController.gauge_exists(address(gauge)), "Gauge was not added to the GaugeController");
            require(!gauge.is_killed(), "Gauge was killed");
            require(gaugesForType.add(address(gauge)), "Gauge already added to the checkpointer");

            // To ensure that the gauge effectively corresponds to the given type, we query the gauge factory registered
            // in the gauge adder for the gauge type.
            // However, since gauges may come from older factories from previous adders, we need to be able to override
            // this check. This way we can effectively still add older gauges to the checkpointer via authorized calls.
            require(
                isGaugeTypeVerified || _gaugeAdder.getFactoryForGaugeType(gaugeType).isGaugeFromFactory(address(gauge)),
                "Gauge does not correspond to the selected type"
            );

            emit IL2GaugeCheckpointer.GaugeAdded(gauge, gaugeType, gaugeType);
        }
    }

    /**
     * @dev Performs checkpoints for all gauges of the given type whose relative weight is at least the specified one.
     * @param gaugeType Type of the gauges to checkpoint.
     * @param minRelativeWeight Threshold to filter out gauges below it.
     * @param currentPeriod Current block time rounded down to the start of the week.
     * This method doesn't check whether the caller transferred enough ETH to cover the whole operation.
     */
    function _checkpointGauges(
        string memory gaugeType,
        uint256 minRelativeWeight,
        uint256 currentPeriod
    ) private {
        EnumerableSet.AddressSet storage typeGauges = _gauges[gaugeType];

        uint256 totalTypeGauges = typeGauges.length();
        if (totalTypeGauges == 0) {
            // Return early if there's no work to be done.
            return;
        }

        // Arbitrum gauges need to send ETH when performing the checkpoint to pay for bridge costs. Furthermore,
        // if gauges come from different factories, the cost per gauge might not be the same for all gauges.
        function(address) internal performCheckpoint = (keccak256(abi.encodePacked(gaugeType)) == _arbitrum)
            ? _checkpointArbitrumGauge
            : _checkpointCostlessBridgeGauge;

        for (uint256 i = 0; i < totalTypeGauges; ++i) {
            address gauge = typeGauges.unchecked_at(i);
            // Skip gauges that are below the threshold.
            if (_gaugeController.gauge_relative_weight(gauge, currentPeriod) < minRelativeWeight) {
                continue;
            }
            performCheckpoint(gauge);
        }
    }

    /**
     * @dev Performs checkpoint for Arbitrum gauge, forwarding ETH to pay bridge costs.
     */
    function _checkpointArbitrumGauge(address gauge) private {
        uint256 checkpointCost = ArbitrumRootGauge(gauge).getTotalBridgeCost();
        _authorizerAdaptorEntrypoint.performAction{ value: checkpointCost }(
            gauge,
            abi.encodeWithSelector(IStakelessGauge.checkpoint.selector)
        );
    }

    /**
     * @dev Performs checkpoint for non-Arbitrum gauge; does not forward any ETH.
     */
    function _checkpointCostlessBridgeGauge(address gauge) private {
        _authorizerAdaptorEntrypoint.performAction(gauge, abi.encodeWithSelector(IStakelessGauge.checkpoint.selector));
    }

    function _returnLeftoverEthIfAny() private {
        // Send back any leftover ETH to the caller.
        // Most gauge types don't need to send value, and this step can be skipped in those cases.
        uint256 remainingBalance = address(this).balance;
        if (remainingBalance > 0) {
            Address.sendValue(msg.sender, remainingBalance);
        }
    }

    /**
     * @dev Rounds the provided timestamp down to the beginning of the current week (Thurs 00:00 UTC).
     */
    function _roundDownTimestamp(uint256 timestamp) private pure returns (uint256) {
        // Division by zero or overflows are impossible here.
        return (timestamp / 1 weeks) * 1 weeks;
    }
}

// File: contracts/gauges/StakelessGauge.sol



// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.7.0;

import "@balancer-labs/v2-interfaces/contracts/solidity-utils/openzeppelin/IERC20.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IBalancerTokenAdmin.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IGaugeController.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IMainnetBalancerMinter.sol";
import "@balancer-labs/v2-interfaces/contracts/liquidity-mining/IStakelessGauge.sol";

import "@balancer-labs/v2-solidity-utils/contracts/math/Math.sol";
import "@balancer-labs/v2-solidity-utils/contracts/openzeppelin/ReentrancyGuard.sol";

abstract contract StakelessGauge is IStakelessGauge, ReentrancyGuard {
    uint256 public constant MAX_RELATIVE_WEIGHT_CAP = 1e18;

    IERC20 internal immutable _balToken;
    IBalancerTokenAdmin private immutable _tokenAdmin;
    IMainnetBalancerMinter private immutable _minter;
    IGaugeController private immutable _gaugeController;
    IAuthorizerAdaptor private immutable _authorizerAdaptor;

    event Checkpoint(uint256 indexed periodTime, uint256 periodEmissions);

    // solhint-disable var-name-mixedcase
    uint256 private immutable _RATE_REDUCTION_TIME;
    uint256 private immutable _RATE_REDUCTION_COEFFICIENT;
    uint256 private immutable _RATE_DENOMINATOR;
    // solhint-enable var-name-mixedcase

    uint256 private _rate;
    uint256 private _period;
    uint256 private _startEpochTime;

    uint256 private _emissions;
    bool private _isKilled;

    uint256 private _relativeWeightCap;

    constructor(IMainnetBalancerMinter minter) {
        IBalancerTokenAdmin tokenAdmin = IBalancerTokenAdmin(minter.getBalancerTokenAdmin());
        IERC20 balToken = tokenAdmin.getBalancerToken();
        IGaugeController gaugeController = minter.getGaugeController();

        _balToken = balToken;
        _tokenAdmin = tokenAdmin;
        _minter = minter;
        _gaugeController = gaugeController;
        _authorizerAdaptor = gaugeController.admin();

        _RATE_REDUCTION_TIME = tokenAdmin.RATE_REDUCTION_TIME();
        _RATE_REDUCTION_COEFFICIENT = tokenAdmin.RATE_REDUCTION_COEFFICIENT();
        _RATE_DENOMINATOR = tokenAdmin.RATE_DENOMINATOR();

        // Prevent initialisation of implementation contract
        // Choice of `type(uint256).max` prevents implementation from being checkpointed
        _period = type(uint256).max;
    }

    // solhint-disable-next-line func-name-mixedcase
    function __StakelessGauge_init(uint256 relativeWeightCap) internal {
        require(_period == 0, "Already initialized");

        // Because we calculate the rate locally, this gauge cannot
        // be used prior to the start of the first emission period
        uint256 rate = _tokenAdmin.rate();
        require(rate != 0, "BalancerTokenAdmin not yet activated");

        _rate = rate;
        _period = _currentPeriod();
        _startEpochTime = _tokenAdmin.startEpochTimeWrite();
        _setRelativeWeightCap(relativeWeightCap);
    }

    function checkpoint() external payable override nonReentrant returns (bool) {
        require(msg.sender == address(_authorizerAdaptor), "SENDER_NOT_ALLOWED");
        uint256 lastPeriod = _period;
        uint256 currentPeriod = _currentPeriod();

        if (lastPeriod < currentPeriod) {
            _gaugeController.checkpoint_gauge(address(this));

            uint256 rate = _rate;
            uint256 newEmissions = 0;
            lastPeriod += 1;
            uint256 nextEpochTime = _startEpochTime + _RATE_REDUCTION_TIME;
            for (uint256 i = lastPeriod; i < lastPeriod + 255; ++i) {
                if (i > currentPeriod) break;

                uint256 periodTime = i * 1 weeks;
                uint256 periodEmission = 0;
                uint256 gaugeWeight = getCappedRelativeWeight(periodTime);

                if (nextEpochTime >= periodTime && nextEpochTime < periodTime + 1 weeks) {
                    // If the period crosses an epoch, we calculate a reduction in the rate
                    // using the same formula as used in `BalancerTokenAdmin`. We perform the calculation
                    // locally instead of calling to `BalancerTokenAdmin.rate()` because we are generating
                    // the emissions for the upcoming week, so there is a possibility the new
                    // rate has not yet been applied.

                    // Calculate emission up until the epoch change
                    uint256 durationInCurrentEpoch = nextEpochTime - periodTime;
                    periodEmission = (gaugeWeight * rate * durationInCurrentEpoch) / 10**18;
                    // Action the decrease in rate
                    rate = (rate * _RATE_DENOMINATOR) / _RATE_REDUCTION_COEFFICIENT;
                    // Calculate emission from epoch change to end of period
                    uint256 durationInNewEpoch = 1 weeks - durationInCurrentEpoch;
                    periodEmission += (gaugeWeight * rate * durationInNewEpoch) / 10**18;

                    _rate = rate;
                    _startEpochTime = nextEpochTime;
                    nextEpochTime += _RATE_REDUCTION_TIME;
                } else {
                    periodEmission = (gaugeWeight * rate * 1 weeks) / 10**18;
                }

                emit Checkpoint(periodTime, periodEmission);
                newEmissions += periodEmission;
            }

            _period = currentPeriod;
            _emissions += newEmissions;

            if (newEmissions > 0 && !_isKilled) {
                _minter.mint(address(this));
                _postMintAction(newEmissions);
            }
        }

        return true;
    }

    function _currentPeriod() internal view returns (uint256) {
        // solhint-disable-next-line not-rely-on-time
        return (block.timestamp / 1 weeks) - 1;
    }

    function _postMintAction(uint256 mintAmount) internal virtual;

    // solhint-disable func-name-mixedcase

    function user_checkpoint(address) external pure override returns (bool) {
        return true;
    }

    function integrate_fraction(address user) external view override returns (uint256) {
        require(user == address(this), "Gauge can only mint for itself");
        return _emissions;
    }

    function is_killed() external view override returns (bool) {
        return _isKilled;
    }

    function killGauge() external override {
        require(msg.sender == address(_authorizerAdaptor), "SENDER_NOT_ALLOWED");
        _isKilled = true;
    }

    function unkillGauge() external override {
        require(msg.sender == address(_authorizerAdaptor), "SENDER_NOT_ALLOWED");
        _isKilled = false;
    }

    function setRelativeWeightCap(uint256 relativeWeightCap) external override {
        require(msg.sender == address(_authorizerAdaptor), "SENDER_NOT_ALLOWED");
        _setRelativeWeightCap(relativeWeightCap);
    }

    function _setRelativeWeightCap(uint256 relativeWeightCap) internal {
        require(relativeWeightCap <= MAX_RELATIVE_WEIGHT_CAP, "Relative weight cap exceeds allowed absolute maximum");
        _relativeWeightCap = relativeWeightCap;
        emit RelativeWeightCapChanged(relativeWeightCap);
    }

    function getRelativeWeightCap() external view override returns (uint256) {
        return _relativeWeightCap;
    }

    function getCappedRelativeWeight(uint256 time) public view override returns (uint256) {
        return Math.min(_gaugeController.gauge_relative_weight(address(this), time), _relativeWeightCap);
    }
}