contract GasTopUpLimit is ControllableOwnable, SelfCallableOwnable {
    event SetGasTopUpLimit(address _sender, uint256 _amount);
    event SubmittedGasTopUpLimitUpdate(uint256 _amount);

    uint256 private constant _MAXIMUM_GAS_TOPUP_LIMIT = 500 finney;
    uint256 private constant _MINIMUM_GAS_TOPUP_LIMIT = 1 finney;

    using DailyLimitTrait for DailyLimitTrait.DailyLimit;

    DailyLimitTrait.DailyLimit internal _gasTopUpLimit;

    /// @dev Constructor initializes the daily gas topup limit in wei.
    constructor() internal {
        _gasTopUpLimit = DailyLimitTrait.DailyLimit(_MAXIMUM_GAS_TOPUP_LIMIT, _MAXIMUM_GAS_TOPUP_LIMIT, now, 0, false);
    }

    /// @dev Confirm pending set top up gas limit operation.
    function confirmGasTopUpLimitUpdate(uint256 _amount) external onlyController {
        _gasTopUpLimit._confirmLimitUpdate(_amount);
        emit SetGasTopUpLimit(msg.sender, _amount);
    }

    /// @dev View your available gas top-up limit
    function gasTopUpLimitAvailable() external view returns (uint256) {
        return _gasTopUpLimit._getAvailableLimit();
    }

    /// @dev Is there an active gas top-up limit change
    function gasTopUpLimitPending() external view returns (uint256) {
        return _gasTopUpLimit.pending;
    }

    /// @dev Has the gas top-up limit been initialised
    function gasTopUpLimitControllerConfirmationRequired() external view returns (bool) {
        return _gasTopUpLimit.controllerConfirmationRequired;
    }

    /// @dev View how much gas top-up has been spent already
    function gasTopUpLimitValue() external view returns (uint256) {
        return _gasTopUpLimit.value;
    }

    /// @dev Sets the daily gas top up limit.
    /// @param _amount is the gas top up amount in wei.
    function setGasTopUpLimit(uint256 _amount) external onlyOwnerOrSelf {
        require(_MINIMUM_GAS_TOPUP_LIMIT <= _amount && _amount <= _MAXIMUM_GAS_TOPUP_LIMIT, "out of range top-up");
        _gasTopUpLimit._setLimit(_amount);
        emit SetGasTopUpLimit(msg.sender, _amount);
    }

    /// @dev Submit a daily gas top up limit update.
    /// @param _amount is the daily top up gas limit amount in wei.
    function submitGasTopUpLimitUpdate(uint256 _amount) external onlyOwnerOrSelf {
        require(_MINIMUM_GAS_TOPUP_LIMIT <= _amount && _amount <= _MAXIMUM_GAS_TOPUP_LIMIT, "out of range top-up");
        _gasTopUpLimit._submitLimitUpdate(_amount);
        emit SubmittedGasTopUpLimitUpdate(_amount);
    }
}
/// @title GasTopUpLimit provides daily limit functionality.
function gasTopUpLimitPending() external view returns (uint256) {
        return _gasTopUpLimit.pending;
    }
/// @dev Is there an active gas top-up limit change