    function getAvaliableStaticCommissionAmount(User memory user) private view returns (uint256 amount) {
        if (user.currentInvestAmount == 0) {
            amount = 0;
        } else {
            uint256 commissionDays = now.sub(user.currentInvestTime).div(ONE_DAY);
            if (commissionDays > user.currentInvestCycle) {
                commissionDays = user.currentInvestCycle;
            }
            amount = user.currentInvestAmount.mul(user.currentStaticCommissionRatio).mul(commissionDays);
            amount = amount.div(1000);
            amount = amount.sub(user.currentStaticCommissionWithdrawAmount);
        }
    }