interface iOVM_BondManager {

    /*******************
     * Data Structures *
     *******************/

    /// The lifecycle of a proposer's bond
    enum State {
        // Before depositing or after getting slashed, a user is uncollateralized
        NOT_COLLATERALIZED,
        // After depositing, a user is collateralized
        COLLATERALIZED,
        // After a user has initiated a withdrawal
        WITHDRAWING
    }

    /// A bond posted by a proposer
    struct Bond {
        // The user's state
        State state;
        // The timestamp at which a proposer issued their withdrawal request
        uint32 withdrawalTimestamp;
        // The time when the first disputed was initiated for this bond
        uint256 firstDisputeAt;
        // The earliest observed state root for this bond which has had fraud
        bytes32 earliestDisputedStateRoot;
        // The state root's timestamp
        uint256 earliestTimestamp;
    }

    // Per pre-state root, store the number of state provisions that were made
    // and how many of these calls were made by each user. Payouts will then be
    // claimed by users proportionally for that dispute.
    struct Rewards {
        // Flag to check if rewards for a fraud proof are claimable
        bool canClaim;
        // Total number of `recordGasSpent` calls made
        uint256 total;
        // The gas spent by each user to provide witness data. The sum of all
        // values inside this map MUST be equal to the value of `total`
        mapping(address => uint256) gasSpent;
    }


    /********************
     * Public Functions *
     ********************/

    function recordGasSpent(
        bytes32 _preStateRoot,
        bytes32 _txHash,
        address _who,
        uint256 _gasSpent
    ) external;

    function finalize(
        bytes32 _preStateRoot,
        address _publisher,
        uint256 _timestamp
    ) external;

    function deposit() external;

    function startWithdrawal() external;

    function finalizeWithdrawal() external;

    function claim(
        address _who
    ) external;

    function isCollateralized(
        address _who
    ) external view returns (bool);

    function getGasSpent(
        bytes32 _preStateRoot,
        address _who
    ) external view returns (uint256);
}
/**
 * @title iOVM_BondManager
 */
function recordGasSpent(
        bytes32 _preStateRoot,
        bytes32 _txHash,
        address _who,
        uint256 _gasSpent
    ) external;
/********************
 * Public Functions *
 ********************/